TWI768722B - Touch panel, display device, optical sheet, and screening method of optical sheet - Google Patents

Abstract

The present invention provides a touch panel, a display device, an optical sheet, and a screening method for an optical sheet, which have outdoor anti-glare properties, can suppress the decrease in resolution, and are excellent in the operability of the touch panel. The touch panel of the present invention has unevenness on the surface of the operator side, and the arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cut-off value of the unevenness is set to 2.5 mm is 0.10 μm or more and 0.60 μm or less, and The friction coefficient of the above-mentioned uneven surface satisfies a specific condition.

Description

Screening method for touch panel, display device, optical sheet and optical sheet

The present invention relates to a touch panel, a display device, an optical sheet and a screening method for the optical sheet.

In recent years, a display device with a touch panel in which a touch panel is mounted on a display device has rapidly spread. Such a display device with a touch panel is below medium size (A4 type below 20 inches to 15 inches, B5 type below 15 inches to more than 11 inches), especially small and below (below 11 inches ) size is convenient for carrying, so it is mostly used outdoors or in a car where sunlight will be incident on the screen. Therefore, in order to prevent the reflection of sunlight, it is desired to impart anti-glare properties to the surface of the touch panel. As an optical sheet imparting anti-glare properties, Patent Document 1 is proposed, for example.

[Patent Document 1] Japanese Patent Laid-Open No. 2013-178534

[The problem to be solved by the invention]

Patent Document 1 is excellent in anti-glare property for indoor lighting. However, the anti-glare property for sunlight (outdoor anti-glare property) is not sufficient. In addition, in recent years, touch panels have enabled various operations such as not only moving a finger in one direction, but also expanding and shrinking the screen on the touch panel. If an optical sheet with a high level of anti-glare property is used as the surface material of the touch panel, there is a problem that the operability of the touch panel as described above is easily degraded. In Patent Document 1, no study has been made to achieve both the outdoor anti-glare property and the operability of the touch panel. In addition, regarding the anti-glare film disposed on the surface of currently commercially available large-screen TVs, PC monitors, etc., not only the operability of the touch panel, but also the anti-glare property against sunlight (outdoor anti-glare property) is not considered. ).

The present invention has been made in view of such a situation, and an object of the present invention is to provide a touch panel, a display device, an optical sheet, and a touch panel, a display device, an optical sheet, and the Screening methods for optical sheets. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a touch panel, a display device, an optical sheet, and a screening method of the optical sheet according to the following [1] to [8].

[1] A touch panel having concavities and convexities on the surface of the operator side, a sapphire needle with a tip radius of 0.3 mm is made to vertically contact the above concavities and convexities, a vertical load of 100 g is applied to the squeegee, and at the same time the squeegee is made to The needle reciprocates once with a one-way length of 10 mm at a speed of 10 mm/s, and the static friction coefficient acting on the scraping needle at this time is set to μs ₁₀ ; the scraping needle made of sapphire with a front end radius of 0.3 mm is vertically contacted with the needle. For the above-mentioned irregularities, apply a vertical load of 100 g to the scraping needle, and at the same time make the scraping needle go back and forth with a one-way length of 10 mm at a speed of 20 mm/sec. The static friction coefficient acting on the scraping needle at this time is set as When μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following condition (A1), and the arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cut-off value is set to 2.5 mm satisfies the following condition (A2) ). 0.70≦μs ₂₀ ／μs ₁₀ ≦1.75 (A1) 0.10 μm≦Ra _2.5 ≦0.60 μm (A2) [2] A display device, the outermost surface on the emitting surface side of the display element has concavities and convexities, so that the front end radius A sapphire needle of 0.3 mm is in contact with the above-mentioned concavities and convexes vertically, and a vertical load of 100 g is applied to the scraping needle, and at the same time, the scraping needle is made to perform a round trip with a single stroke length of 10 mm at a speed of 10 mm/sec. At this time, the static friction coefficient acting on the scraping needle is set to μs ₁₀ ; the scraping needle made of sapphire with a front end radius of 0.3 mm is made to contact the above-mentioned unevenness vertically, a vertical load of 100 g is applied to the scraping needle, and at the same time, the scraping needle is When the speed of 20 mm/sec is carried out with a single round trip length of 10 mm, and the static friction coefficient acting on the squeegee is set to μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following conditions (A1), regarding the above irregularities The arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cutoff value is 2.5 mm satisfies the following condition (A2). 0.70≦μs ₂₀ ／μs ₁₀ ≦1.75 (A1) 0.10 μm≦Ra _2.5 ≦0.60 μm (A2) [3] An optical sheet with unevenness on one side, so that a sapphire needle with a tip radius of 0.3 mm vertically contacts the above Concave and convex, apply a vertical load of 100 g to the scraping needle, and at the same time make the scraping needle make a round trip with a one-way length of 10 mm at a speed of 10 mm/s, and set the static friction coefficient acting on the scraping needle at this time as μs _10. Make a sapphire needle with a radius of 0.3 mm at the front end contact the above-mentioned concave and convex vertically, apply a vertical load of 100 g to the scraping needle, and at the same time make the scraping needle carry out a single stroke of 10 mm at a speed of 20 mm/s. One reciprocation, when the static friction coefficient acting on the squeegee at this time is μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following condition (A1), and the cut-off value of the above-mentioned unevenness is set to 2.5 mm JIS The arithmetic mean roughness (Ra _2.5 ) of B0601:1994 satisfies the following condition (A2). 0.70≦μs ₂₀ ／μs ₁₀ ≦1.75 (A1) 0.10 μm≦Ra _2.5 ≦0.60 μm (A2) [4] A screening method for an optical sheet, which is a screening method for an optical sheet with unevenness on one side, and the screening method is selected The following optical sheet is used as the optical sheet on the uppermost part of the touch panel. A sapphire needle with a radius of 0.3 mm at the front end is vertically contacted with the above-mentioned unevenness. At a speed of 10 mm/s, make a round trip with a one-way length of 10 mm, and set the static friction coefficient acting on the squeegee at this time as μs ₁₀ ; make the sapphire squeegee with a front end radius of 0.3 mm vertically contact the above-mentioned concave and convex , apply a vertical load of 100 g to the scraping needle, and at the same time make the scraping needle perform a round trip with a one-way length of 10 mm at a speed of 20 mm/sec. The static friction coefficient acting on the scraping needle at this time is set to μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following condition (A1), and the arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cut-off value is 2.5 mm satisfies the following condition (A2) . 0.70≦μs ₂₀ ／μs ₁₀ ≦1.75 (A1) 0.10 μm≦Ra _2.5 ≦0.60 μm (A2)

[5] A touch panel having concavities and convexities on a surface on the operator side, and the concavities and convexities satisfy the following conditions (B1) and (B2). Condition (B1): A sapphire needle with a tip radius of 0.3 mm was made to vertically contact the above-mentioned unevenness, a vertical load Tg was applied to the above-mentioned squeegee, and at the same time, the squeegee was made to carry out a single pass length of 10 at a speed of 5 mm/sec. 1 round trip of mm, measure the static friction coefficient μs and dynamic friction coefficient μk acting on the scraping needle at this time. In the graph plotted with the ratio of the above-mentioned static friction coefficient μs to the above-mentioned dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load of 100 to 1000 g is borrowed. When approximated by a first-order straight line by the least squares method, the slope of the above-mentioned first-order straight line is negative. Condition (B2): Regarding the irregularities, the arithmetic mean roughness (Ra2.5) of JIS B0601:1994 when the cutoff value is 2.5 mm is 0.10 μm or more and 0.60 μm or less. [6] A display device having concavities and convexities on an outermost surface of a display element on an outgoing surface side, and the concavities and convexities satisfy the following conditions (B1) and (B2). Condition (B1): A sapphire needle with a tip radius of 0.3 mm was made to vertically contact the above-mentioned unevenness, a vertical load Tg was applied to the above-mentioned squeegee, and at the same time, the squeegee was made to perform a single pass at a speed of 5 mm/sec. A round trip of 10 mm is performed once, and the static friction coefficient μs and dynamic friction coefficient μk acting on the scraping needle are measured at this time. In the graph drawn with the ratio (μs/μk) of the above-mentioned static friction coefficient μs to the above-mentioned dynamic friction coefficient μk as the vertical axis, and the above-mentioned vertical load Tg as the horizontal axis, the curve in the range of the vertical load of 100 to 1000 g is calculated by When the least squares method is approximated by a first-order straight line, the slope of the first-order straight line is negative. Condition (B2): Regarding the irregularities, the arithmetic mean roughness (Ra2.5) of JIS B0601:1994 when the cutoff value is 2.5 mm is 0.10 μm or more and 0.60 μm or less. [7] An optical sheet having unevenness on one surface, and the unevenness satisfies the following conditions (B1) and (B2). Condition (B1): A sapphire needle with a tip radius of 0.3 mm was made to vertically contact the above-mentioned unevenness, a vertical load Tg was applied to the above-mentioned squeegee, and at the same time, the squeegee was made to carry out a single pass length of 10 at a speed of 5 mm/sec. 1 round trip of mm, measure the static friction coefficient μs and dynamic friction coefficient μk acting on the scraping needle at this time. In the graph plotted with the ratio (μs/μk) of the above-mentioned static friction coefficient μs to the above-mentioned dynamic friction coefficient μk as the vertical axis and the vertical load Tg as the horizontal axis, the vertical load in the range of 100 to 1000 g will be When the curve is approximated by a first-order straight line by the least squares method, the slope of the first-order straight line is negative. Condition (B2): Regarding the irregularities, the arithmetic mean roughness (Ra2.5) of JIS B0601:1994 when the cutoff value is 2.5 mm is 0.10 μm or more and 0.60 μm or less. [8] A screening method for an optical sheet, wherein an optical sheet having concavities and convexities on one surface and the concavities and convexities satisfying the following conditions (B1) and (B2) is selected as an optical sheet located on the uppermost part of a touch panel. Condition (B1): A sapphire needle with a tip radius of 0.3 mm was made to vertically contact the above-mentioned unevenness, a vertical load Tg was applied to the above-mentioned squeegee, and at the same time, the squeegee was made to carry out a single pass length of 10 at a speed of 5 mm/sec. 1 round trip of mm, measure the static friction coefficient μs and dynamic friction coefficient μk acting on the scraping needle at this time. In the graph plotted with the ratio of the above-mentioned static friction coefficient μs to the above-mentioned dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load of 100 to 1000 g is borrowed. When approximated by a first-order straight line by the least squares method, the slope of the above-mentioned first-order straight line is negative. Condition (B2): Regarding the irregularities, the arithmetic mean roughness (Ra2.5) of JIS B0601:1994 when the cutoff value is 2.5 mm is 0.10 μm or more and 0.60 μm or less. [Effect of invention]

According to the present invention, it is possible to provide a touch panel, a display device, an optical sheet, and a screening method for an optical sheet, which have outdoor anti-glare properties, can suppress a decrease in resolution, and have excellent touch panel operability.

Hereinafter, the touch panel, the display device, the optical sheet, and the screening method of the optical sheet of the present invention will be described by taking Embodiment A and Embodiment B as examples. <Embodiment A> [Touch Panel] The touch panel of Embodiment A has concavities and convexities on the surface of the operator side. Apply a vertical load of 100 g, and at the same time make the scraping needle make a round trip with a one-way length of 10 mm at a speed of 10 mm/sec. The static friction coefficient acting on the scraping needle at this time is set to μs ₁₀ , and the front end radius is 0.3 A sapphire needle with a size of mm is vertically in contact with the above-mentioned concavities and convexities, and a vertical load of 100 g is applied to the scraper needle, and at the same time, at a speed of 20 mm/sec, one round trip with a one-way length of 10 mm is performed. When the static friction coefficient of the squeegee is set to μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following conditions (A1), and about the above-mentioned unevenness, the arithmetic mean roughness of JIS B0601:1994 (Ra _2.5 when the cut-off value is set to 2.5 mm) ) meets the following conditions (A2). 0.70≦μs ₂₀ ／μs ₁₀ ≦1.75 (A1) 0.10 μm≦Ra _2.5 ≦0.60 μm (A2) In Embodiment A, the so-called “surface on the operator’s side” refers to the actual contact surface when the operator operates the touch panel. Operational side.

As a touch panel, an electrostatic capacitance type touch panel, a resistive film type touch panel, an optical type touch panel, an ultrasonic type touch panel, an electromagnetic induction type touch panel, etc. are mentioned. These touch panels have transparent substrates such as glass substrates and plastic film substrates, and there are cases where concavities and convexities for imparting anti-glare properties are formed on the transparent substrates. The touch panel of Embodiment A has, for example, the following optical sheet on the uppermost part as such a member having irregularities on the transparent substrate.

As shown in FIG. 1 , a resistive film touch panel 1 is connected to a circuit (not shown) that is arranged via a spacer 13 in such a way that the conductive films 12 having a pair of transparent substrates 11 above and below the conductive film 12 are opposed to each other. into the basic composition. In the case of the resistive film type touch panel, in Embodiment A, the following optical sheet is used as the upper transparent substrate. By using the following optical sheet as the upper transparent substrate of the resistive film type touch panel as described above, the touch panel can be provided with outdoor anti-glare property by utilizing the uneven shape of the optical sheet, and the operability of the touch panel can be improved. Excellent. In addition, reduction in resolution can be suppressed. In addition, the above-mentioned optical sheet can be used as a lower transparent substrate in addition to being used as an upper transparent substrate.

The capacitive touch panel includes a surface type and a projection type, and the projection type is often used. The projection-type electrostatic capacitive touch panel is formed by connecting a circuit to a basic configuration in which an X-axis electrode and a Y-axis electrode orthogonal to the X-axis electrode are arranged with an insulator interposed therebetween. To describe the basic structure in more detail, it can be mentioned that the X-axis electrodes and the Y-axis electrodes are formed on different surfaces of one transparent substrate; the X-axis electrodes, the insulator layer, the The state of the Y-axis electrode; as shown in FIG. 2 , the X-axis electrode 22 is formed on one transparent substrate 21, the Y-axis electrode 23 is formed on the other transparent substrate 21, and the layered state is performed through an adhesive layer 24, etc. Wait. Moreover, the aspect in which another transparent substrate is further laminated|stacked among these basic aspects is mentioned. In the case of the capacitive touch panel, in Embodiment A, the following optical sheet is used as the uppermost transparent substrate. By using the following optical sheet for the uppermost transparent substrate of the electrostatic capacitive touch panel as described above, the touch panel can be provided with outdoor anti-glare properties by utilizing the uneven shape of the optical sheet, and the touch panel can be Workability becomes excellent. In addition, reduction in resolution can be suppressed. The above-mentioned touch panel is used, for example, as a surface-mounted touch panel provided on a display element.

(Optical Sheet) The optical sheet of Embodiment A has unevenness on one surface, and the unevenness satisfies the above-mentioned conditions (A1) and (A2). The touch panel may require different operating speeds. In the condition (A1), if μs ₂₀ /μs ₁₀ is less than 0.70, the operation feeling of scrolling the screen cannot be obtained, and/or the enlargement/reduction operation cannot be performed smoothly. If it exceeds 1.75, the scroll operation cannot be performed smoothly, and/or the operation feeling of enlargement/reduction cannot be obtained. On the other hand, when the optical sheet of Embodiment A satisfies the condition (A1), in any operation of the touch panel, the degree of finger jamming at the start of the operation can be made the same, and the operability can be improved. Condition (A1) preferably satisfies 0.80≦μs ₂₀ /μs ₁₀ ≦1.60, more preferably 0.85≦μs ₂₀ /μs ₁₀ ≦1.25, and more preferably 0.85≦μs ₂₀ /μs ₁₀ ≦1.15. In addition, in Embodiment A, the static friction coefficient is set as the peak value of the initial friction force that is equal to or higher than the kinetic friction coefficient with the elapse of the measurement time from the friction force 0.

In addition, from the viewpoint of improving operability, μs ₂₀ and μs ₁₀ are preferably in the following ranges. μs ₂₀ is preferably 0.10 to 0.26, more preferably 0.11 to 0.25, and still more preferably 0.12 to 0.24. μs ₁₀ is preferably 0.12 to 0.18, more preferably 0.13 to 0.17, still more preferably 0.14 to 0.16.

In addition, in the condition (A2), the cutoff value was set to 2.5 mm. The cutoff value is a value indicating how much the waviness component is cut off from the profile curve composed of the roughness component (high frequency component) and the waviness component (low frequency component). In other words, the cutoff value is a value indicating the fineness of the filter for cutting off the waviness component (low frequency component) from the profile curve. If the cutoff value is large, the filter is sparse, so the large ripples in the waviness component will be cut off, but the small ripples will not be cut off. On the other hand, if the cutoff value is small, the filter is denser, so that the waviness component is basically cut off. In JIS B0633 referred to in JIS B0601, when the arithmetic mean roughness Ra is 0.1 to 2 μm, the cutoff value (reference length) is set to 0.8 mm. Therefore, according to JIS B0633, in the case of Ra of the above condition (A2), the standard is to set the cut-off value (reference length) to 0.8 mm. However, the touch feeling during operation, outdoor anti-glare performance, and resolution are not only affected by the roughness component (high frequency component), but also by the waviness component (low frequency component), so the cutoff value (reference length ) is set to 0.8 mm, the waviness component (low frequency component) of the roughness curve is cut off to a greater extent, and it is impossible to evaluate the operation that is more easily affected by the low frequency component than the outdoor anti-glare and resolution. The tactile danger of time. Therefore, in Embodiment A, the cutoff value of the condition (A2) is set to 2.5 mm.

The arithmetic mean roughness Ra _2.5 of the condition (A2) is 0.10 μm or more and 0.60 μm or less. When Ra _2.5 is less than 0.10 μm, the light scattering is insufficient and the anti-glare property is lowered. In addition, the contact area between the finger and the surface of the optical sheet increases and the touch feeling (sliding feeling) deteriorates. When Ra _2.5 exceeds 0.60 μm, the sliding property during handling is impaired, and the contrast and resolution are lowered. From the viewpoints of touch during operation, outdoor anti-glare property, and resolution, the condition (A2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, and more preferably satisfies 0.25 μm≦Ra _2.5 ≦0.55 μm. Moreover, when the arithmetic mean roughness Ra _2.5 is 0.10 μm or more, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made less noticeable. The so-called gradation color unevenness unique to the retardation value is the color unevenness of the rainbow pattern generated by the light passing through the transparent substrate with the retardation value. , when the light of a transparent substrate with a specific retardation value is observed. Furthermore, by satisfying the following conditions (A3) to (A5) in addition to the above-mentioned condition (A2), it becomes easier to satisfy the above-mentioned condition (A1). Especially when Ra _2.5 is 0.25 μm or more, for example, a display element with a wide color gamut can make the color unevenness of the gradation more difficult to notice.

Moreover, it is preferable that the said unevenness|corrugation satisfy|fills the following conditions (A3) with the ten-point average roughness (Rz _2.5 ) of JIS B0601:1994 when the cut-off value is 2.5 mm, and the above-mentioned Ra _2.5 . 5.7≦Rz _2.5 /Ra _2.5 (A3)

The arithmetic mean roughness Ra is a value obtained by integrating the absolute values of the elevations of the peaks and valleys of the roughness curve of the evaluation length and dividing by the evaluation length to obtain equal elevations. On the other hand, the ten-point average roughness Rz is calculated by dividing the roughness curve with an evaluation length of N times the sampling length equal to the cut-off value into N equal parts, and obtaining the first to fifth heights of each section. The arithmetic mean of N Rz's when the interval Rz' between the average elevation of the peak and the average elevation of the bottom of the 1st to 5th depths. That is, Ra is the average value of the elevations of the entire roughness curve, whereas Rz is the average value of the elevations when the five upper and lower five positions in the roughness curve are emphasized. Therefore, when the roughness curve does not have randomness, Ra and Rz are approximately the same, but when the roughness curve has randomness, Rz becomes larger than Ra. Therefore, Rz/Ra becomes an index representing the randomness of the roughness curve.

When Rz _2.5 /Ra _2.5 is 5.7 or more, the irregularity of the roughness curve increases, the contact area between fingers and the surface of the optical sheet decreases, and the touch becomes favorable. In addition, by increasing the randomness of the roughness curve, there is a tendency for the color unevenness of the gradation to be more difficult to notice for display elements with a wide color gamut. Furthermore, from the viewpoint of touch (sliding feeling) and resolution, it is preferable that the roughness does not cause excessive randomness. The condition (A3) is more preferably satisfied 6.0≦Rz _2.5 /Ra _2.5 ≦10.0, more preferably 6.5≦Rz _2.5 /Ra _2.5 ≦9.5, and more preferably 7.0≦Rz _2.5 /Ra _2.5 ≦9.0.

Furthermore, the Rz _2.5 of the unevenness is preferably 0.50 to 4.30 μm, more preferably 1.00 to 4.00 μm, and still more preferably 2.00 to 4.00 μm. When Rz _2.5 is 0.50 μm or more, outdoor anti-glare properties can be imparted to the touch panel, and the touch feeling (sliding feeling) can be further improved. When Rz _2.5 is 4.30 μm or less, the generation of glare can be suppressed, and the sliding property during operation is not impaired. Furthermore, if Rz _2.5 is 2.00 μm or more, for example, in a display device with a wide color gamut, the color unevenness of the gradation characteristic of the retardation value of the transparent substrate can be made more difficult to notice.

Moreover, about the said unevenness, it is preferable that the average interval (S _2.5 ) of local peaks in JIS B0601:1994 when the cutoff value is 2.5 mm satisfies the following condition (A4). S _2.5 ≦70 μm (A4)

When the average interval (S _2.5 ) of the local peaks is 70 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (sliding feeling) can be improved. Condition (A4) preferably satisfies S _2.5 ≦65 μm, more preferably 20 μm≦S _2.5 ≦60 μm, and more preferably 30 μm≦S _2.5 ≦55 μm.

Furthermore, it is preferable that the ten-point average roughness (Rz _0.8 ) of JIS B0601:1994 when the cut-off value is 0.8 mm and the above-mentioned Rz _2.5 satisfy the following condition (A5) about the above-mentioned unevenness. 0.10 μm≦Rz _2.5 －Rz _0.8 ≦1.20 μm (A5)

As described above, the cutoff value is a value indicating the degree to which the waviness component is cut off from the cross-sectional profile curve composed of the free roughness component (high frequency component) and the waviness component (low frequency component). Therefore, Rz _2.5 - Rz _0.8 can be regarded as an indicator of the degree of the influence of the waviness component on Rz. In the case where the condition (A5) is satisfied, the static friction coefficient can be easily made the same in the case of contacting the unevenness at a low speed and the case of contacting the unevenness at a high speed. The operation of the touch panel can be roughly divided into: the operation of scrolling the screen, and the operation of expanding or reducing the display. Between the former operation and the latter operation, the former operation tends to move the finger faster. In addition, the ease of the finger jamming with respect to the waviness component varies according to the speed of moving the finger. That is, when the condition (A5) is satisfied, in any operation of the touch panel, it is easy to make the degree of finger sticking (static friction coefficient) at the beginning of the operation to be the same. Moreover, by setting Rz _2.5 to Rz _0.8 within the above-mentioned range, glare can be easily suppressed.

The condition (A5) more preferably satisfies 15 μm≦Rz _2.5 −Rz _0.8 ≦0.80 μm, and more preferably satisfies 0.20 μm≦Rz _2.5 −Rz _0.8 ≦0.50 μm. Furthermore, Rz _2.5 - Rz _0.8 is preferably more than 0.50 μm, more preferably more than 0.80 μm, from the viewpoint of making the gradation peculiar to the retardation value of the transparent substrate inconspicuous.

In any operation of the touch panel, it is easy to make the degree of stuttering (static friction coefficient) of the finger at the beginning of the operation to be the same degree, and it is preferable that the above-mentioned unevenness is Rz _2.5 /Rz _0.8 to satisfy the following conditions. Rz _2.5 /Rz _0.8 ≦1.50 Furthermore, from the viewpoint of suppressing glare and from the viewpoint of making the gradation peculiar to the retardation value of the transparent substrate less noticeable, Rz _2.5 /Rz _0.8 is more preferably 1.20 or more and 1.50 or less, and more preferably 1.25 or more and 1.35 or less.

Furthermore, it is preferable that the maximum height (Ry _2.5 ) of JIS B0601:1994 when the cut-off value is set to 2.5 mm satisfies the following conditions regarding the above-mentioned unevenness. 0.60 μm≦Ry _2.5 ≦5.0 μm If Ry _2.5 is 5.0 μm or less, it can prevent the fingers from getting stuck during operation and make the touch feeling better. In addition, the generation of glare can be further prevented. When Ry _2.5 is 0.60 μm or more, outdoor anti-glare properties can be imparted. In addition, from the viewpoint of easily satisfying the following conditions (A6) and (A7), Ry _2.5 is more preferably 1.0 μm or more and 4.7 μm or less, and still more preferably 1.2 μm or more and 4.5 μm or less.

Furthermore, it is preferable that the said unevenness|corrugation satisfy|fills the following condition (A6) with the said (Ry _2.5 ) and the said Rz _2.5 . Ry _2.5 /Rz _2.5 ≦1.5 (A6) If Ry _2.5 /Rz _2.5 is less than 1.5, it can prevent the fingers from getting stuck during operation, and make the touch feel better. In addition, the generation of glare can be further prevented, and outdoor anti-glare properties can be easily imparted. Ry _2.5 /Rz _2.5 is more preferably 1.10 or more and 1.40 or less, and still more preferably 1.18 or more and 1.38 or less.

Furthermore, it is preferable that the average inclination angle (θa _2.5 ) of the unevenness when the cutoff value is set to 2.5 mm satisfies the following conditions. 1.0°≦θa _2.5 ≦5.5° When θa _2.5 is 1.0° or more, outdoor anti-glare properties can be imparted to the touch panel, and the touch (sliding feeling) during operation can be improved. When θa _2.5 is 5.5° or less, a decrease in contrast can be suppressed, and both outdoor anti-glare properties and contrast can be achieved. θa _2.5 preferably satisfies 1.3°≦θa _2.5 ≦4.5°, and more preferably satisfies 2.0°≦θa _2.5 ≦4.0°. Moreover, when θa _2.5 is 1.3° or more, the color unevenness of the gradation peculiar to the retardation value of the transparent base material can be made less noticeable. Furthermore, if it is 2.0° or more, for example, in a display element having a wide color gamut, the color unevenness of the gradation can be made more difficult to notice. Here, the "average inclination angle θa" is the value defined in the operation manual (revised on July 20, 1995) of the surface roughness measuring device (trade name: SE-3400) manufactured by Kosaka Research Institute, as shown in Fig. 3, It can be obtained by arctangent θa = tan ^{- 1} _{ (h _{1 +} h _{2 +} h ₃ +・・_・+h _n )/L} to obtain.

[式（A）中，「L」表示基準長度，「dy／dx」表示粗糙度曲線之各單位區間之斜率]。 再者，所謂「基準長度」，意指「截止值」。即，於截止值為0.8 mm之情形時，基準長度為0.8 mm。又，所謂單位測量區間，係用截止值除以取樣數所得之長度之區間。取樣數設為1500。In addition, θa can be calculated according to the following formula (A).

[In the formula (A), "L" represents the reference length, and "dy/dx" represents the slope of each unit section of the roughness curve]. In addition, the so-called "reference length" means "cutoff value". That is, when the cutoff value is 0.8 mm, the reference length is 0.8 mm. In addition, the so-called unit measurement interval is the interval of the length obtained by dividing the cutoff value by the number of samples. The number of samples is set to 1500.

Furthermore, it is preferable that the said unevenness|corrugation is such that the said ((theta)a _2.5 ) and the said Ry _2.5 /Rz _2.5 satisfy the following condition (A7). 0.8≦θa _2.5 /(Ry _2.5 /Rz _2.5 )≦5.0 (A7) If θa _2.5 /(Ry _2.5 /Rz _2.5 ) is within the above range, unevenness with moderate randomness can be obtained, and the anti-glare property, Resolution, tactile feel (sliding feeling) during handling, and a balance that makes the gradation peculiar to the retardation value of the transparent base material less noticeable. θa _2.5 /(Ry _2.5 /Rz _2.5 ) is more preferably 1.0 or more and 4.5 or less, and even in the case of a display element with a wide color gamut, the color unevenness of the gradation can be difficult to be noticed, so it is more preferably 2.0 or more and 4.0 or less.

Furthermore, it is preferable that the average interval (Sm _2.5 ) of the unevenness according to JIS B0601:1994 when the cut-off value is 2.5 mm satisfies the following conditions. Sm _2.5 ≦160 μm When Sm _2.5 is 160 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (sliding feeling) can be improved. Sm _2.5 is more preferably 150 μm or less, and still more preferably 145 μm or less. Moreover, the lower limit is preferably 30 μm or more, more preferably 50 μm or more, and still more preferably 100 μm or more. Furthermore, the smaller the Sm _2.5 is, the more it can suppress the generation of glare even if it is a high-definition display.

Examples of methods for forming the aforementioned concavities and convexities include (x1) physical or chemical treatments such as embossing, sandblasting, and etching, (x2) molding with a mold, and (x3) formation of a concavo-convex layer by coating. Among these methods, from the viewpoint of the reproducibility of the concavo-convex shape, (x2) molding by a mold is preferable, and from the viewpoint of productivity and correspondence to various types, (x3) the concavo-convex by coating is preferable formation of layers.

Molding by a mold can be formed by making a mold composed of a shape complementary to the concavity and convexity, pouring the material forming the concavity and convexity into the mold, and then taking it out from the mold. Here, if the material constituting the concavo-convex is used as the material, the material is poured into the mold, the transparent substrate is stacked, and the concavity and convexity are taken out from the mold together with the transparent substrate, an optical sheet with concavo-convex on the transparent substrate can be obtained. . Moreover, if the material which comprises a transparent base material is poured into a mold and taken out from the mold, an optical sheet composed of a single layer of a transparent base material and having unevenness on the surface of the transparent base material can be obtained. When a curable resin composition (thermosetting resin composition or ionizing radiation curable resin composition) is used as the material to be poured into the mold, it is preferable to harden the curable resin composition before being taken out from the mold. In terms of excellent reproducibility of the concavo-convex shape, it is preferable to form the concavo-convex shape using a mold.

The formation of the concavo-convex layer by coating can be performed by applying a concavo-convex layer-forming coating solution containing a resin component and particles on a transparent substrate by a known coating method such as gravure coating and bar coating. It is formed by drying and hardening as necessary. In order for the uneven layer to satisfy the above-mentioned conditions (A1) and (A2), the film thickness of the uneven layer, the content of particles, and the average particle diameter of the particles are preferably within the following ranges.

The thickness of the uneven layer is preferably 1.5 to 10 μm, more preferably 2 to 8 μm, and still more preferably 3 to 7 μm. The thickness of the concavo-convex layer can be measured at 20 locations from an image of a cross-section captured by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), for example, and the average value of the values at the 20 locations can be measured. and calculate. The acceleration voltage of TEM or STEM is preferably set to 1-5 kV, and the magnification is preferably set to 1000-10,000 times.

Any of organic particles and inorganic particles can be used as long as the particles can form irregularities. The organic particles include polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysilicon Particles composed of oxygen, fluorine-based resin, polyester-based resin, etc. Examples of the inorganic particles include particles composed of silica, alumina, zirconia, titania, and the like. Among these particles, light-transmitting organic particles or silica particles are preferred from the viewpoint of ease of dispersion control. The above-mentioned particles may be used alone or in combination of two or more different in material or particle size.

In addition, in order to make the color unevenness of gradation difficult to be noticeable even in the case of a display device with a wide color gamut, the particles are preferably indeterminate particles having a particle diameter equal to or greater than the wavelength of visible light. The unevenness of the gradation can be suppressed by containing the irregular particles in the concavo-convex layer.

The content of the particles is preferably 5 to 25% by mass, more preferably 6 to 22% by mass, and still more preferably 10 to 20% by mass of the total solid content forming the concavo-convex layer.

The average particle diameter of the particles in the concave-convex layer varies depending on the thickness of the concave-convex layer, and therefore cannot be generalized, but from the viewpoint of easily satisfying the conditions (A1) and (A2), it is preferably 1.0 to 10.0 μm, more preferably It is 1.5-8.0 micrometers, More preferably, it is 2.0-6.0 micrometers. When the particles are aggregated, the average particle diameter of the aggregated particles preferably satisfies the above range. The average particle diameter of the particles can be calculated by the following operations (y1) to (y3). (y1) The particle that appears to be the largest in the observation frame is selected from the images of the cross-sections captured using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). The acceleration voltage of TEM or STEM is preferably set to 1-30 kV, and the magnification is preferably set to 5000 to 300,000 times. (y2) The particles with the largest diameter appearing to be selected from the observed image, and the particle diameter of each particle is calculated. The particle size is measured in the form of the distance between the straight lines. The distance between the straight lines is when the cross section of the particle is clamped by any two parallel straight lines. If the distance between the two straight lines becomes the largest in the combination of the two straight lines. distance. (y3) The same operation was performed on the observation image of the other screen of the same sample, and the value obtained from the number average of the particle diameters of a total of 20 pieces was set as the average particle diameter of the particles. In addition, in the case of agglomerated particles, the largest diameter portion of the agglomerates is regarded as the particle size. In addition, the average particle diameter of the following ultrafine particles can be calculated by the same method as the above-mentioned (y1) to (y3). When calculating the average particle size of the ultrafine particles, the accelerating voltage of the TEM or STEM is preferably set to 10 kV to 30 kV, and the magnification is preferably set to 10,000 to 300,000 times.

From the viewpoint of easily satisfying the above-mentioned conditions (A1) and (A2) for the concavo-convex layer, the film thickness of the concavo-convex layer is preferably larger than the average particle diameter of the particles. Moreover, more specifically, the ratio of [average particle diameter of particle]/[film thickness of uneven|corrugated layer] becomes like this. Preferably it is 0.20-0.99, More preferably, it is 0.50-0.90. The particles can also be those with a wide particle size distribution (single particle with a wide particle size distribution, or a mixture of two or more particles with different particle size distributions and a wide particle size distribution), from the viewpoint of suppressing glare In terms of particle size distribution, a narrower particle size distribution is preferred.

Moreover, as a particle, it is preferable to contain not only the micron-order particle as mentioned above, but also nano-order ultrafine particle. By containing nano-scale ultrafine particles, the uneven layer can easily satisfy the above-mentioned conditions (A1) and (A2). It can be considered that the reason is that in the case of ultrafine particles, a gentle slope is formed even where there are no particles, and low-frequency bumps are formed (truncated at the cutoff value of 0.8 mm, but not at the cutoff value of 2.5 mm). truncated bump). In the case of containing ultrafine particles, the thixotropy of the coating solution and the drying characteristics of the solvent will be affected, and the usual leveling will not occur, so it is considered that the above phenomenon will occur.

The ultrafine particles are preferably inorganic fine particles. Examples of the inorganic ultrafine particles include ultrafine particles composed of silica, alumina, zirconia, titania, and the like. Among these, from the viewpoint of transparency, silica ultrafine particles are preferred. The ultrafine particles preferably have an average primary particle diameter of 1 to 25 nm, more preferably 5 to 20 nm. Within the said range, the uneven|corrugated layer becomes easy to satisfy|fill the said conditions (A1) and (A2).

The ultrafine particles are preferably surface-treated ultrafine particles, or reactive ultrafine particles into which reactive groups are further introduced. By introducing surface treatment, it becomes easy to obtain balance with the organic binder or solvent in the uneven layer, and the uneven layer can easily satisfy the above-mentioned conditions (A1) and (A2). Examples of such surface-treated ultrafine particles include inorganic ultrafine particles surface-treated with a silane coupling agent. When the surface of the inorganic ultrafine particles is treated with a silane coupling agent, a dry method in which the silane coupling agent is sprayed onto the inorganic ultrafine particles; Wet method, etc. In the case of introducing a reactive group, a polymerizable unsaturated group, preferably a photocurable unsaturated group, and particularly preferably a free radiation curable unsaturated group can be preferably used. Specific examples thereof include (meth)acryloyl groups, (meth)acryloyloxy groups, ethylenically unsaturated bonds such as vinyl groups and allyl groups, and epoxy groups.

The content of the ultrafine particles is preferably 0.2 to 60 mass % of the total solid content forming the uneven layer. The content of the ultrafine particles can be adjusted depending on the purpose of using the ultrafine particles, but from the viewpoint of improving hardness or scratch resistance, it is preferably 15 to 50% by mass, and from the viewpoints of improving optical properties and preparing unevenness, more Preferably it is 0.4-10 mass %. Moreover, by setting it in the said range, the uneven|corrugated layer becomes easy to satisfy|fill the above-mentioned conditions (A1) and (A2) by controlling the leveling property and suppressing the polymerization shrinkage of the uneven|corrugated layer. Moreover, when other particles are contained in the uneven layer, the content ratio of other particles to ultrafine particles (content of other particles/content of ultrafine particles) is preferably 0.05 to 3.0, more preferably 0.1 to 1.5, and the upper limit is more preferably is 0.7 or less. By setting it in the said range, the uneven|corrugated layer becomes easy to satisfy|fill the said conditions (A1) and (A2). Furthermore, only by aggregating ultrafine particles, it is possible to form particles of the order of μm to form irregularities.

The resin component of the concavo-convex layer preferably contains a thermosetting resin composition or an ionizing radiation curable resin composition, and more preferably contains an ionizing radiation curable resin composition from the viewpoint of improving mechanical strength, wherein, Furthermore, it is preferable to contain an ultraviolet curable resin composition.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition hardened by heating. As a thermosetting resin, an acrylic resin, a urethane resin, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, a silicone resin, etc. are mentioned. In the thermosetting resin composition, if necessary, a curing agent is added to these curable resins.

The ionizing radiation curable resin composition is a composition containing a compound having a ionizing radiation curable functional group (hereinafter, also referred to as "ion radiation curable compound"). Examples of free radiation curable functional groups include ethylenically unsaturated bonding groups such as (meth)acryloyl groups, vinyl groups, and allyl groups, epoxy groups, oxetanyl groups, and the like. The ionized radiation curable compound is preferably a compound having an ethylenically unsaturated bond group, more preferably a compound having two or more ethylenically unsaturated bond groups, and still more preferably a compound having two or more ethylenically unsaturated bond groups A polyfunctional (meth)acrylate-based compound of an ethylenically unsaturated bond group. As the polyfunctional (meth)acrylate-based compound, both monomers and oligomers can be used. Furthermore, the so-called ionizing radiation refers to electromagnetic waves or charged particle beams with energy quanta that can polymerize or cross-link molecules, usually ultraviolet (UV) or electron beam (EB), in addition, X-rays, Electromagnetic waves such as gamma rays; charged particle beams such as alpha rays and ion beams.

Among the polyfunctional (meth)acrylate-based compounds, the bifunctional (meth)acrylate-based monomers include ethylene glycol di(meth)acrylate and bisphenol A tetraethoxy diacrylate , bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, dicyclopentenyl di(meth)acrylate, triethylene glycol diacrylate, tetraethylene glycol di( Meth)acrylate, tricyclodecanediyl dimethylene di(meth)acrylate, tris(2-hydroxyethyl)trimeric isocyanate di(meth)acrylate, and the like. Trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, neotaerythritol can be mentioned as a trifunctional or more than trifunctional (meth)acrylate type monomer, for example Tri(meth)acrylate, neotaerythritol tetra(meth)acrylate, neotaerythritol hexa(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, dipivale Tetraol Hexa (meth)acrylate, Dipivalerythritol Penta (meth)acrylate, Dipivalerythritol Tetra (meth)acrylate, Di-trimethylolpropane Tetra (meth)acrylate , Tris (2-hydroxyethyl) trimeric isocyanate tri (meth) acrylate, etc. In addition, the above-mentioned (meth)acrylate-based monomer may be a part of which the molecular skeleton is modified, and may also be used in the form of ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, Cyclic alkyl, aromatic, bisphenol, etc. are modified.

Moreover, as a polyfunctional (meth)acrylate type oligomer, urethane (meth)acrylate (urethane (meth)acrylate), epoxy (meth)acrylate, polyester (meth)acrylate can be mentioned. ) acrylate-based polymers such as acrylates, polyether (meth)acrylates, and the like. The amine ester (meth)acrylate can be obtained, for example, by the reaction of a polyol and an organic diisocyanate with a hydroxy (meth)acrylate. In addition, preferable epoxy (meth)acrylate is (meth)acrylic acid obtained by reacting trifunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with (meth)acrylic acid. base) acrylate; (meth)acrylate obtained by reacting aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with 2 or more functions with polybasic acids and (meth)acrylic acid; And the (meth)acrylate obtained by making a bifunctional or more aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, etc. react with a phenol and (meth)acrylic acid. The above-mentioned ionizing radiation curable compounds may be used alone or in combination of two or more.

類等中之1種以上。 上述光聚合起始劑中，較佳適當選擇雙(2,4,6－三甲基苯甲醯基)－苯基氧化膦、寡(2－羥基－2－甲基－1－[4－(1－甲基乙烯基)苯基]丙酮、2－羥基－2－甲基－1－苯基－丙烷－1－酮、1－羥基－環己基－苯基－酮及2－甲基－1－(4－甲基噻吩基)－2－N-

啉基丙烷－1－酮中之1種或複數種。When the ionized radiation curable compound is an ultraviolet curable compound, the ionized radiation curable composition preferably contains additives such as a photopolymerization initiator or a photopolymerization accelerator. Examples of the photopolymerization initiator include: acetophenone, benzophenone, α-hydroxyalkylphenone, α-aminoalkylphenone, α-hydroxyketone, Micheler ketone, benzoin, benzoin methyl ketal, benzalyl benzoate, α-acyl oxime ester, acyl phosphine oxides, 9-oxysulfur 𠮿

1 or more of the categories, etc. Among the above photopolymerization initiators, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, oligo(2-hydroxy-2-methyl-1-[4- (1-Methylvinyl)phenyl]acetone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-one and 2-methyl- 1-(4-Methylthienyl)-2-N-

One or more of olinylpropane-1-ones.

The photopolymerization initiator is not limited to the above-mentioned compounds, and any one may be used as long as it has the ability to initiate polymerization by ultraviolet rays. These photopolymerization initiators may be used alone or in combination of two or more. The content of the photopolymerization initiator in the ionized radiation curable resin composition is not particularly limited, but is preferably used within the range of 1 to 20 parts by mass relative to 100 parts by mass of the total amount of the ultraviolet curable compound. When using a plurality of types, it is preferable to use each within the above-mentioned range.

The photopolymerization initiator preferably has a melting point of 100°C or higher. By setting the melting point of the photopolymerization initiator to be 100°C or higher, the photopolymerization initiator remaining due to the heat during the formation of the transparent conductive film of the touch panel or the crystallization process sublimates, thereby preventing damage to the transparent conductive film. of low resistance. In addition, the photopolymerization accelerator can reduce the polymerization inhibition by air at the time of curing and accelerate the curing speed, for example, one selected from the group consisting of isoamyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate One or more of esters and the like.

Moreover, it is preferable that the uneven|corrugated layer forming coating liquid contains a leveling agent. As a leveling agent, a fluorine type leveling agent, a polysiloxane type leveling agent, a fluorine polysiloxane copolymer type leveling agent etc. are mentioned, for example. Among them, a polysiloxane-based leveling agent can be preferably used from the viewpoint of easily satisfying the above-mentioned conditions (A1) and (A2) for the uneven layer. Moreover, compared with reactive ones, non-reactive ones tend to have favorable touch panel operability. The addition amount of the leveling agent is preferably 0.01 to 5.0% by weight with respect to the total solid content of the uneven layer.

The unevenness of the optical sheet is preferably formed by antifouling treatment. By performing the antifouling treatment, the surface shape of the embodiment A can be prevented from being damaged by the stains remaining in the unevenness. In addition, the antifouling treatment using a fluorine-based mold release agent or a polysiloxane-based mold release agent is preferable in that it imparts slidability to the unevenness, satisfies the condition (A1) easily, and can make the feel more favorable. . As a means of antifouling treatment, a means of making the uneven layer contain a release agent such as a fluorine-based mold release agent and a polysiloxane-based mold release agent, and forming a mold release layer on the outermost surface of the optical sheet with the above-mentioned mold release agent can be mentioned. the means. When the concavo-convex layer contains a mold release agent, the content of the mold release agent is preferably 0.5 to 5.0 mass % of the total solid content of the concavo-convex layer.

(transparent substrate) As a transparent base material used for an optical sheet, what has light transmittance, smoothness, heat resistance, and is excellent in mechanical strength is preferable. Examples of such transparent substrates include polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether, polyether, Polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane and amorphous olefin (Cyclo-Olefin- Polymer: COP) and other plastic films. The transparent substrate can also be formed by laminating two or more plastic films. In addition, in addition to the above-mentioned plastic films manufactured by general methods such as extrusion molding (inflation method, T-die method) or solution casting method: solution casting, calendering method: calendaring, etc. A coating film made of resin such as an ionizing radiation curable resin composition is formed on a base material having releasability, and the film is produced by peeling the coating film from the base material.

Among the above, from the viewpoint of mechanical strength or dimensional stability, polyester (polyethylene terephthalate, polyethylene naphthalate, polyethylene naphthalate, etc. )). In addition, COP and polyester are preferable in that they are excellent in weather resistance.

The thickness of the transparent substrate is preferably 5-300 μm, more preferably 10-200 μm, and still more preferably 20-130 μm. In order to improve the adhesiveness, the surface of the transparent substrate can be subjected to physical treatment such as corona discharge treatment and oxidation treatment in advance. In addition, a paint called a tackifier or a primer can also be applied in advance.

The transparent substrate preferably has a retardation value exceeding 0 nm and less than 3,000 nm, more preferably exceeding 20 nm and 2,000 nm or less. The retardation value is set to a value at a wavelength of 550 nm. The retardation value of the transparent substrate is determined by the following formula, and is determined by the refractive index _nx in the direction of the in-plane refractive index of the transparent substrate that is the largest in the direction of the retardation axis, the in-plane direction of the transparent substrate and the direction of the retardation axis. The orthogonal direction is represented by the refractive index _ny in the direction of the progressive axis and the thickness d of the transparent substrate, and is referred to as the so-called "in-plane retardation". Retardation value (Re)=( _nx - _ny )×d The above-mentioned retardation value can be measured by, for example, the trade names “KOBRA-WR” and “PAM-UHR100” manufactured by Oji Scientific Instruments.

Usually, when a transparent substrate with a small retardation value is used, the color unevenness of the gradient color generated by the light passing through the transparent substrate is observed (for example, through polarized sunglasses, a transparent material with a specific retardation value is recognized through a polarizing plate. observed in the light of the substrate). However, since the optical sheet used in the touch panel of Embodiment A satisfies the condition (A2), even if a transparent substrate with a small retardation value is used, the color unevenness of the gradation can be hardly noticeable. Furthermore, even if the retardation value is reduced, the fact that the color unevenness of the gradation can be made inconspicuous is related to the thinning of the base material thickness of the transparent base material. That is, with regard to a transparent substrate (for example, a polyester film, which is a general-purpose substrate) that generates retardation, generally, by performing uniaxial stretching to increase the thickness of the substrate, etc., the retardation value is increased, thereby suppressing the occurrence of retardation. The gradient is uneven. However, with regard to the optical sheet used in the touch panel of the embodiment A, even if the thickness of the transparent substrate (for example, polyester film as a general substrate) is reduced, the color unevenness of the gradation can be caused Hard to notice. Furthermore, even if the retardation value is made small, the case where the uneven color of the gradation can be made less noticeable is related to the situation that it is usually possible to use the color unevenness of the gradation, which is easy to produce, and it is beyond the scope of choice. Plastic film (polyimide film, polyaramide film). A polyimide film and a polyaramide film are preferable in that they are excellent in flexibility resistance. In recent years, the color gamut of display elements tends to expand. A display element with a wide color gamut has a steep shape in the spectral spectrum of each color (R, G, B). For such a display element, the color unevenness of the gradation specific to the retardation value tends to be particularly noticeable. The optical sheet used in the touch panel of the embodiment A is preferable in that even in a display element with a wide color gamut, the color unevenness of the gradation can be hardly noticeable.

The optical sheet may also have functional layers such as an antireflection layer, an antifouling layer, and an antistatic layer on the concavo-convex and/or the surface opposite to the concavo-convex. Moreover, when there exists a structure of an uneven|corrugated layer on a transparent base material, in addition to the said part, you may have a functional layer between a transparent base material and an uneven|corrugated layer. Furthermore, when other functional layers are laminated on the concavo-convex layer, the concavo-convex on the outermost surface satisfies the scope of this case. The concavo-convex may be a single layer or a plurality of layers as long as the outermost surface is within the scope of the present invention.

The touch panel of Embodiment A is provided with outdoor anti-glare properties by the uneven shape of the optical sheet, and is excellent in operability. In addition, the reduction in resolution can be suppressed. Therefore, the touch panel of the embodiment A is preferably installed on the output surface side of the display element of a smartphone or tablet (multifunctional mobile terminal) carried by a vehicle-mounted display device and a train or the like when moving.

[display device] The display device of Embodiment A is a display device in which the outermost surface on the output surface side of the display element has unevenness, and the unevenness satisfies the above-mentioned conditions (A1) and (A2). The display apparatus of Embodiment A can use the same optical sheet used for the touch panel of Embodiment A mentioned above as a member which has unevenness|corrugation on the outermost surface.

As a display element, a liquid crystal display element, an in-cell touch panel liquid crystal display element, an EL display element, a plasma display element, etc. are mentioned. Furthermore, the liquid crystal display element has a backlight device on the back of the liquid crystal element. The in-cell touch panel liquid crystal element is a liquid crystal element formed by sandwiching liquid crystals between two glass substrates and has touch panel functions such as resistive film type, electrostatic capacitance type, and optical type. In addition, as a display method of the liquid crystal of an in-cell touch panel liquid crystal element, an IPS method, a VA method, a multi-domain method, an OCB method, an STN method, a TSTN method, etc. are mentioned. The in-cell touch panel liquid crystal element is described in, for example, Japanese Patent Laid-Open No. 2011-76602 and Japanese Patent Laid-Open No. 2011-222009.

The optical sheet can be provided on the output surface side of the display element, for example, in the following order. (a) Display element/surface protection plate/optical sheet (b) Display element/optical sheet (c) Touch panel with display element/optical sheet on top In the case of (a) and (b), outdoor anti-glare properties can be imparted to the display device by arranging the unevenness of the optical sheet toward the opposite side to the display element. In addition, the reduction in the resolution of the display element can be suppressed, and the scratches generated on the surface or the display element can be made difficult to see. In the case of (c), the display device becomes a display device with a touch panel provided with a touch panel having an optical sheet on the uppermost part on the output surface side of the display element. In this case, a display device excellent in outdoor anti-glare property, high resolution, and operability of the touch panel can be produced. Therefore, the display device of Embodiment A is preferably used as a display device for in-vehicle use, a smartphone or a tablet (multifunctional mobile terminal) carried when traveling in a train or the like.

As described above, with regard to the optical sheet used in the display device of the embodiment A, even for a display element with a wide color gamut, the color unevenness of the gradation can be hardly noticeable. As a standard for expressing color gamut, "ITU-R recommends BT.2020 (hereinafter, referred to as "BT.2020")" and the like. ITU-R is the abbreviation of "International Telecommunication Union-Radiocommunication Sector", and ITU-R advises BT.2020 to be the international standard for the color gamut of high-definition television. Regarding the display device of the embodiment A, even for a display element with a coverage rate of 60% or more based on the CIE-xy chromaticity diagram of the BT.2020 represented by the following formula, the color unevenness of the gradation is difficult to attract. Attention. ＜Formula representing the coverage of BT.2020＞ [In the area of the CIE-xy chromaticity diagram of the display element, the area that overlaps with the area of the CIE-xy chromaticity diagram of BT.2020 / the area of the CIE-xy chromaticity diagram of BT.2020] × 100 (%)

Furthermore, the "area of the CIE-xy chromaticity diagram" necessary to calculate the coverage of BT.2020 is to measure the CIE- The x-value and y-value of the Yxy color system can be obtained from the "red (R) vertex coordinates", "green (G) vertex coordinates" and "blue (B) vertex coordinates" obtained from the measurement results "Calculate. The x value and the y value of the CIE-Yxy colorimetric system can be measured, for example, with a spectroradiometer CS-2000 manufactured by Konica Minolta. Examples of display elements with a wide color gamut include: three-color independent organic EL display devices (among them, three-color independent organic EL elements with a microcavity structure), liquid crystal display elements using quantum dots for backlight devices, backlight devices The device uses a liquid crystal display element such as a white LED (near-ultraviolet LED, a combination of a blue phosphor, a green phosphor, and a red phosphor) of a three-wavelength method.

[Optical sheet] The optical sheet of Embodiment A has unevenness|corrugation on one surface, and this unevenness|corrugation satisfies the said conditions (A1) and (A2). Furthermore, in the optical sheet of Embodiment A, when other functional layers are laminated on the above-mentioned unevenness, the unevenness of the outermost surface satisfies the scope of the present application. The concavo-convex may be a single layer or a plurality of layers as long as the outermost surface is within the scope of the present invention. As an optical sheet of Embodiment A, the same optical sheet used for the touch panel of Embodiment A mentioned above is mentioned.

When using the optical sheet of Embodiment A for a touch panel, this optical sheet is provided so that the surface which has unevenness|corrugation may become the surface of the operator side of a touch panel. In order to satisfy the above-mentioned conditions (A1) and (A2), the optical sheet of Embodiment A is provided on the uppermost part of the touch panel, thereby imparting outdoor anti-glare properties to the touch panel, and making the touch panel The operability becomes excellent. Therefore, the optical sheet of the embodiment A can be preferably used on the surface of a vehicle-mounted display device, and the surface of a smartphone or tablet (multifunctional mobile terminal) carried when a train or the like moves.

[Screening method of optical sheet] The screening method of the optical sheet of Embodiment A is to select an optical sheet with unevenness on one side and the unevenness satisfying the above-mentioned conditions (A1) and (A2) as the optical sheet located on the uppermost part of the touch panel.

In the screening method of the optical sheet of the embodiment A, even if the operability test of the optical sheet is not performed, the optical sheet with good operability, outdoor anti-glare property and high resolution can be screened efficiently. Product design and quality management of optical sheets.

Regarding the judgment conditions for screening the optical sheet of the touch panel, the above-mentioned conditions (A1) and (A2) are set as necessary conditions. The determination condition of the condition (A1) preferably satisfies 0.80≦μs ₂₀ /μs ₁₀ ≦1.65, and more preferably satisfies 0.85≦μs ₂₀ /μs ₁₀ ≦1.55. Moreover, the determination condition of the condition (A2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, and more preferably satisfies 0.25 μm≦Ra _2.5 ≦0.55 μm.

Regarding the screening method of the optical sheet of the touch panel, it is more preferable to set one or more of the following conditions (A3) to (A5) as new from the viewpoints of the tactile sensation during operation and the outdoor anti-glare property. It is preferable to set all of (A3) to (A5) as the newly added judgment conditions. 5.7≦Rz _2.5 /Ra _2.5 (A3) S _2.5 ≦70 μm (A4) 0.10 μm≦Rz _2.5 −Rz _0.8 ≦1.50 μm (A5) The judgment conditions of the conditions (A3) to (A5) are preferably the above-mentioned Embodiment A The preferred numerical range of the optical sheet. Furthermore, other parameters are preferably set as the newly added determination conditions.

<Embodiment B> [Touch Panel] The touch panel of Embodiment B has unevenness on the surface of the operator side, and the unevenness satisfies the following conditions (B1) and (B2). Condition (B1): A sapphire needle with a tip radius of 0.3 mm was made to vertically contact the above-mentioned unevenness, a vertical load Tg was applied to the above-mentioned squeegee, and at the same time, the squeegee was made to carry out a single pass length of 10 at a speed of 5 mm/sec. 1 round trip of mm, measure the static friction coefficient μs and dynamic friction coefficient μk acting on the scraping needle at this time. In the graph plotted with the ratio of the above-mentioned static friction coefficient μs to the above-mentioned dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load of 100 to 1000 g is borrowed. When approximated by the least squares method with a first-order line, the slope of the first-order line is negative. Condition (B2): The arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cut-off value of the unevenness is 2.5 mm is 0.10 μm or more and 0.60 μm or less. In Embodiment B, the so-called "surface on the operator side" refers to the surface that the operator actually touches and operates when operating the touch panel.

As a touch panel, an electrostatic capacitance type touch panel, a resistive film type touch panel, an optical type touch panel, an ultrasonic type touch panel, an electromagnetic induction type touch panel, etc. are mentioned. These touch panels may have transparent substrates such as glass substrates and plastic film substrates, and irregularities for imparting anti-glare properties are formed on the transparent substrates. The touch panel of Embodiment B has, for example, the following optical sheet on the uppermost part as such a member having irregularities on the transparent substrate.

As shown in FIG. 1 , the resistive film type touch panel 1 is connected to a circuit (not shown) with a spacer 13 interposed therebetween so that the conductive films 12 having a pair of transparent substrates 11 above and below the conductive film 12 are opposed to each other. The basic composition of the made. In the case of a resistive film type touch panel, in Embodiment B, the following optical sheet is used as an upper transparent substrate. By using the following optical sheet as the upper transparent substrate of the resistive film type touch panel as described above, the touch panel can be provided with outdoor anti-glare property by utilizing the uneven shape of the optical sheet, and the operability of the touch panel can be improved. Excellent. In addition, reduction in resolution can be suppressed. In addition, the above-mentioned optical sheet can also be used as a lower transparent substrate together with an upper transparent substrate.

The capacitive touch panel includes a surface type and a projection type, and the projection type is often used. The projection-type electrostatic capacitive touch panel is formed by connecting a circuit to a basic configuration in which an X-axis electrode and a Y-axis electrode orthogonal to the X-axis electrode are arranged with an insulator interposed therebetween. If the basic structure is described in more detail, the following examples include: forming the X-axis electrode and the Y-axis electrode on different surfaces of one transparent substrate; forming the X-axis electrode, the insulator layer, the The state of the Y-axis electrode; as shown in FIG. 2, the X-axis electrode 22 is formed on one transparent substrate 21, the Y-axis electrode 23 is formed on the other transparent substrate 21, and the state of lamination is carried out through the adhesive layer 24, etc. Like and so on. Moreover, the aspect in which another transparent substrate is laminated|stacked among these basic aspects can be mentioned. In the case of the electrostatic capacitance type touch panel, in Embodiment B, the following optical sheet is used as the uppermost transparent substrate. By using the following optical sheet for the uppermost transparent substrate of the electrostatic capacitive touch panel as described above, the touch panel can be provided with outdoor anti-glare properties by utilizing the uneven shape of the optical sheet, and the touch panel can be Workability becomes excellent. In addition, reduction in resolution can be suppressed. The above-mentioned touch panel is used, for example, as a surface-mounted touch panel provided on a display element.

(optical sheet) The optical sheet of Embodiment B has unevenness on one surface, and the unevenness satisfies the above-mentioned conditions (B1) and (B2). Fig. 4 is a graph showing the unevenness of the optical sheet according to Embodiment B, with the ratio of the coefficient of static friction μs to the coefficient of kinetic friction μk (μs/μk) on the vertical axis and the vertical load Tg on the horizontal axis, and the vertical load Tg is plotted. The curve in the load range of 100-1000 g is a graph of an approximate first-order straight line obtained by the least squares method. As shown in FIG. 4 , in the optical sheet of Embodiment B, the slope of the above-mentioned approximate first-order straight line is negative, and the ratio (μs/μk) decreases as the load (vertical load) applied to the unevenness of the optical sheet increases. . This means that the larger the vertical load becomes, the more easily the unevenness of the optical sheet becomes deformed, and the smaller the influence of the unevenness becomes.

When performing the operation of changing the direction of the finger on the optical sheet, such as writing characters or drawing graphics, most of them stop for a moment and then start (for example, when changing the direction of the finger, the movement of the finger is usually stopped for a moment; It will also stop the movement of the finger for a moment when the position of the finger). When the movement of the finger is stopped for a moment and then restarted as described above, it is easily affected by the difference between the coefficient of static friction μs and the coefficient of kinetic friction μk. When the vertical load is small, if the ratio (μs/μk) is too small, the fingers tend to slide on the optical sheet and it becomes difficult to change the direction. In addition, when the vertical load is large, if the ratio (μs/μk) is too large, when the finger is oriented on the optical sheet, the finger receives a high load and it becomes difficult to change the direction. Therefore, in order to easily change the direction of the finger on the optical sheet, it is required that when the vertical load is small, the finger does not slide too much to obtain a moderate sense of impedance, and as the vertical load increases, the load applied to the finger is suppressed. . Regarding the optical sheet of Embodiment B, by satisfying the above-mentioned condition (B1), complicated operations such as changing the direction of a finger on the optical sheet can be performed favorably. Furthermore, as the situation where the load is different, for example, there can be mentioned: the situation of operating the terminal while standing in the tram (the operating load at this time is usually light); condition (the operating load at this time is usually heavier). That is, by satisfying the condition (B1), complicated operations such as direction change can be performed favorably under the condition that the posture during operation is different and the operation load is different.

In addition, in Embodiment B, the kinetic friction coefficient μk means the average value of the kinetic friction coefficient of the whole measurement time. In addition, the static friction coefficient μs is assumed to be the peak value of the initial friction force that is equal to or higher than the kinetic friction coefficient with the elapse of the measurement time from the friction force 0. The static friction coefficient μs and the dynamic friction coefficient μk can be measured by a friction and wear tester (manufactured by Xindong Science Co., Ltd., HEIDON NHS2000).

When the vertical load is small, for example, when the load is 50 to 150 g, the ratio (μs/μk) is preferably 1.58 to 2.50 from the viewpoint of obtaining a moderate sense of impedance without excessive sliding, more preferably It is 1.70～2.20. Moreover, when the vertical load is large, for example, when the load is 900 to 1100 g, the ratio (μs/μk) is preferably 1.00 to 1.50, more preferably 1.10 to 1.40, from the viewpoint of suppressing excessive load .

Moreover, in the condition (B1), the slope of the approximate first-order straight line is preferably -10.0×10 ^{−4 to} −4.5×10 ^{−4 , and} more preferably −8.5×10 ^{−4 to} −6.0×10 ⁻⁴ . Within the above range, workability can be further improved.

In addition, in the condition (B2), the cutoff value was set to 2.5 mm. The cutoff value is a value indicating the degree to which the waviness component is cut off from the cross-sectional profile curve composed of the free roughness component (high frequency component) and the waviness component (low frequency component). In other words, the cutoff value is a value indicating the fineness of the filter for cutting off the waviness component (low frequency component) from the profile curve. If the cutoff value is large, the filter is sparse, so the large waviness components are truncated, but the small waviness components are not truncated. On the other hand, if the cutoff value is small, the filter is denser, so that the waviness component is basically cut off. In JIS B0633 referred to in JIS B0601, when the arithmetic mean roughness Ra is 0.1 to 2 μm, the cutoff value (reference length) is set to 0.8 mm. Therefore, according to JIS B0633, in the case of Ra of the above condition (B2), the standard is to set the cut-off value (reference length) to 0.8 mm. However, the touch feeling during operation, outdoor anti-glare performance, and resolution are not only affected by the roughness component (high frequency component), but also by the waviness component (low frequency component), so the cutoff value (reference length ) is set to 0.8 mm, the waviness component (low frequency component) of the roughness curve is cut off to a greater extent, and it is impossible to evaluate the operation that is more easily affected by the low frequency component than the outdoor anti-glare and resolution. The tactile danger of time. Therefore, in Embodiment B, the cutoff value of the condition (B2) was set to 2.5 mm.

Condition (B2) is that the arithmetic mean roughness Ra _2.5 is 0.10 μm or more and 0.60 μm or less. When Ra _2.5 is less than 0.10 μm, the light scattering is insufficient and the anti-glare property is lowered. In addition, the contact area between the finger and the surface of the optical sheet increases and the touch feeling (sliding feeling) deteriorates. When Ra _2.5 exceeds 0.60 μm, the sliding property during handling is impaired, and the contrast and resolution are lowered. From the viewpoints of touch during operation, outdoor anti-glare properties, and resolution, the condition (B2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, more preferably 0.25 μm≦Ra _2.5 ≦0.55 μm, and further Preferably, 0.30 μm≦Ra _2.5 ≦0.50 μm is satisfied. Moreover, when the arithmetic mean roughness Ra _2.5 is 0.10 μm or more, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made less noticeable. The so-called gradation color unevenness unique to the retardation value is the color unevenness of the rainbow pattern generated by the light passing through the transparent substrate with the retardation value. , when the light of a transparent substrate with a specific retardation value is observed. Furthermore, by satisfying the following condition (B3) in addition to the above condition (B2), it becomes easier to satisfy the above condition (B1). In particular, when Ra _2.5 is preferably 0.25 μm or more, more preferably 0.30 μm or more, for example, for a display element with a wide color gamut, the color unevenness of the gradation can be more difficult to notice.

In addition, it is preferable that the above-mentioned unevenness has a ten-point average roughness (Rz _0.8 ) of JIS B0601:1994 when the cutoff value is 0.8 mm, and a ten-point average roughness of JIS B0601:1994 when the cutoff value is 2.5 mm (Rz _2.5 ) The following condition (B3) is satisfied. Rz _0.8 / (Rz _2.5 - Rz _0.8 )≦3.2 (B3)

In the case where the cutoff value is set to 0.8 mm, the degree of cut-off of the low frequency components of the roughness curve becomes larger than that in the case where the cutoff value is set to 2.5 mm. That is, the value of Rz _0.8 can be regarded as the high frequency component in the unevenness of the optical sheet, and the value of (Rz _2.5 - Rz _0.8 ) can be regarded as the low frequency component in the unevenness of the optical sheet. Therefore, "Rz _0.8 /(Rz _2.5 - Rz _0.8 )" of the condition (B3) can be regarded as the ratio of the high-frequency components of the unevenness to the low-frequency components.

In the condition (B3), "Rz _0.8 /(Rz _2.5 - Rz _0.8 ) is 3.2 or less" means that the high frequency component is not too much and there is a certain amount of low frequency Concavities and convexities are easily maintained. On the other hand, concavities and convexities of low frequency components are easily deformed, and it becomes easier to satisfy the above-mentioned condition (B1). Furthermore, it becomes easier to satisfy the condition (B1) by increasing the absolute amount of the unevenness, but in this case, the condition (B2) cannot be satisfied. In other words, it is preferable to satisfy the condition (B1) by satisfying the condition (B3) within the range that satisfies the concavity and convexity of the condition (B2). Condition (B3) more preferably satisfies Rz _0.8 /(Rz _2.5 −Rz _0.8 )≦3.0, and more preferably satisfies Rz _0.8 /(Rz _2.5 −Rz _0.8 )≦2.9. Satisfying Rz _0.8 / (Rz _2.5 - Rz _0.8 )≦3.0 is also related to the following situation: For example, for display elements with a wide color gamut, the color unevenness of the gradient color unique to the retardation value of the transparent substrate can be made more difficult to attract. Attention. Moreover, as a lower limit value of Rz _0.8 /(Rz _2.5 -Rz _0.8 ), 1.0 or more is preferable, 2.0 or more is more preferable, and 2.5 or more is still more preferable.

Moreover, it is preferable that the said unevenness|corrugation is such that the above-mentioned Rz _2.5 and the above-mentioned Ra _2.5 satisfy the following condition (B4). 5.7≦Rz _2.5 /Ra _2.5 (B4)

The arithmetic mean roughness Ra is a value obtained by integrating the absolute values of the elevations of the peaks and valleys of the roughness curve of the evaluation length and dividing by the evaluation length to obtain equal elevations. On the other hand, the ten-point average roughness Rz is calculated by dividing the roughness curve with an evaluation length of N times the sampling length equal to the cut-off value into N equal parts, and obtaining the first to fifth heights of each section. The arithmetic mean of N Rz's when the interval Rz' between the average elevation of the peak and the average elevation of the bottom of the 1st to 5th deepest valleys is Rz'. That is, Ra is the average value of the elevations of the entire roughness curve, whereas Rz is the average value of the elevations when the five upper and lower five positions in the roughness curve are emphasized. Therefore, when the roughness curve does not have randomness, Ra and Rz are approximately the same, but when the roughness curve has randomness, Rz becomes larger than Ra. Therefore, Rz/Ra becomes an index representing the randomness of the roughness curve.

When Rz _2.5 /Ra _2.5 is 5.7 or more, the irregularity of the roughness curve increases, the contact area between fingers and the surface of the optical sheet decreases, and the touch becomes favorable. In addition, by increasing the randomness of the roughness curve, there is a tendency for the color unevenness of the gradation to be more difficult to notice for display elements with a wide color gamut. Furthermore, from the viewpoints of touch (sliding feeling) and resolution, it is preferable that the roughness does not cause excessive randomness. Condition (B4) is more preferably satisfied 6.0≦Rz _2.5 /Ra _2.5 ≦10.0, more preferably 6.5≦Rz _2.5 /Ra _2.5 ≦9.5, and more preferably 7.0≦Rz _2.5 /Ra _2.5 ≦9.0.

The Rz _2.5 of the unevenness is preferably 0.50 to 4.30 μm, more preferably 1.00 to 4.00 μm, and still more preferably 2.00 to 4.00 μm. When Rz _2.5 is 0.50 μm or more, the above-mentioned condition (B1) can be easily satisfied, and outdoor anti-glare property can be imparted to the touch panel, and the touch feeling (sliding feeling) can be further improved. When Rz _2.5 is 4.30 μm or less, the generation of glare can be suppressed, and the sliding property during operation is not impaired. Furthermore, if Rz _2.5 is 2.00 μm or more, for example, in a display device with a wide color gamut, the color unevenness of the gradation characteristic of the retardation value of the transparent substrate can be made more difficult to notice.

Moreover, it is preferable that the said unevenness|corrugation satisfy|fills the following condition (B5) when the cut-off value is set to 2.5 mm, and the local peak average interval (S _2.5 ) of JIS B0601:1994. S _2.5 ≦70 μm (B5)

When the average interval (S _2.5 ) of the local peaks is 70 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (sliding feeling) can be improved. Condition (B5) more preferably satisfies S _2.5 ≦65 μm, more preferably 20 μm≦S _2.5 ≦60 μm, and more preferably 30 μm≦S _2.5 ≦55 μm.

Furthermore, it is preferable that the maximum height (Ry _2.5 ) of JIS B0601:1994 when the cut-off value of the unevenness is set to 2.5 mm satisfies the following conditions. 0.60 μm≦Ry _2.5 ≦5.0 μm If Ry _2.5 is 5.0 μm or less, the fingers can be prevented from getting stuck during operation, and the operability can be improved. In addition, the generation of glare can be further prevented. When Ry _2.5 is 0.60 μm or more, outdoor anti-glare properties can be imparted. In addition, from the viewpoint of easily satisfying the following conditions (B6) and (B7), Ry _2.5 is more preferably 1.0 μm or more and 4.7 μm or less, and still more preferably 1.2 μm or more and 4.5 μm or less.

Furthermore, it is preferable that the said unevenness|corrugation satisfy|fills the following condition (B6) with the said (Ry _2.5 ) and the said Rz _2.5 . Ry _2.5 /Rz _2.5 ≦1.5 (B6) If Ry _2.5 /Rz _2.5 is less than or equal to 1.5, the fingers can be prevented from getting stuck during operation, and the operability can be improved. In addition, the generation of glare can be further prevented, and outdoor anti-glare properties can be easily provided. Ry _2.5 /Rz _2.5 is more preferably 1.10 or more and 1.40 or less, and still more preferably 1.18 or more and 1.37 or less.

Furthermore, it is preferable that the average inclination angle (θa _2.5 ) of the unevenness when the cut-off value is set to 2.5 mm satisfies the following conditions. 1.0°≦θa _2.5 ≦5.5° When θa _2.5 is 1.0° or more, outdoor anti-glare properties can be imparted to the touch panel, and operability can be improved. When θa _2.5 is 5.5° or less, a decrease in contrast can be suppressed, and both outdoor anti-glare properties and contrast can be achieved. θa _2.5 preferably satisfies 1.3°≦θa _2.5 ≦4.5°, and more preferably satisfies 2.0°≦θa _2.5 ≦4.0°. Moreover, when θa _2.5 is 1.3° or more, the color unevenness of the gradation peculiar to the retardation value of the transparent base material can be made less noticeable. Furthermore, if it is preferably 1.5° or more, and more preferably 2.0° or more, for example, in a display element with a wide color gamut, the color unevenness of the gradation can be made more difficult to notice. Here, the "average inclination angle θa" is the value defined in the operation manual (revised on July 20, 1995) of the surface roughness measuring device (trade name: SE-3400) manufactured by Kosaka Research Institute, as shown in Fig. 3, It can be obtained by arctangent θa = tan ^{- 1} _{ (h _{1 +} h _{2 +} h ₃ +・・_・+h _n )/L} to obtain.

[式（A）中，「L」表示基準長度，「dy／dx」表示粗糙度曲線之各單位區間之斜率]。 再者，所謂「基準長度」，意指「截止值」。即，於截止值為0.8 mm之情形時，基準長度為0.8 mm。又，所謂單位測量區間，係用截止值除以取樣數所得之長度之區間。取樣數係設為1500。In addition, θa can be calculated according to the following formula (A).

[In the formula (A), "L" represents the reference length, and "dy/dx" represents the slope of each unit section of the roughness curve]. In addition, the so-called "reference length" means "cutoff value". That is, when the cutoff value is 0.8 mm, the reference length is 0.8 mm. In addition, the so-called unit measurement interval is the interval of the length obtained by dividing the cutoff value by the number of samples. The number of samples is set to 1500.

Furthermore, it is preferable that the said unevenness|corrugation satisfy|fills the following condition (B7) with the said ((theta)a _2.5 ) and the said Ry _2.5 /Rz _2.5 . 0.8≦θa _2.5 /(Ry _2.5 /Rz _2.5 )≦5.0 (B7) If θa _2.5 /(Ry _2.5 /Rz _2.5 ) is within the above range, unevenness with moderate randomness can be obtained, and the anti-glare property, Resolution, tactile feel (sliding feeling) during handling, and a balance that makes the gradation peculiar to the retardation value of the transparent base material less noticeable. θa _2.5 /(Ry _2.5 /Rz _2.5 ) is more preferably 1.0 or more and 4.5 or less, and even in the case of a display element with a wide color gamut, the color unevenness of the gradation can be difficult to be noticed, so it is more preferably 1.2 or more and 4.0 or less.

Furthermore, it is preferable that the average interval (Sm _2.5 ) of the unevenness according to JIS B0601:1994 when the cut-off value is 2.5 mm satisfies the following conditions. Sm _2.5 ≦160 μm When Sm _2.5 is 160 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (sliding feeling) can be improved. Sm _2.5 is more preferably 150 μm or less, and still more preferably 145 μm or less. Moreover, the lower limit is preferably 30 μm or more, more preferably 50 μm or more, and still more preferably 100 μm or more. Furthermore, the smaller the Sm _2.5 is, the more it can suppress the generation of glare even if it is a high-definition display.

Examples of methods for forming the aforementioned concavities and convexities include (x1) physical or chemical treatments such as embossing, sandblasting, and etching, (x2) molding with a mold, and (x3) formation of a concavo-convex layer by coating. Among these methods, from the viewpoint of the reproducibility of the concavo-convex shape, (x2) molding by a mold is preferable, and from the viewpoint of productivity and compatibility with various types, (x3) forming the concavo-convex by coating is preferable Floor.

Molding by a mold can be formed by making a mold composed of a shape complementary to the concavity and convexity, pouring the material forming the concavity and convexity into the mold, and then taking it out from the mold. Here, if the material constituting the concavo-convex is used as the material, the material is poured into the mold, the transparent substrate is stacked, and the concavity and convexity are taken out from the mold together with the transparent substrate, an optical sheet with concavo-convex on the transparent substrate can be obtained. . Moreover, if the material which comprises a transparent base material is poured into a mold and taken out from the mold, an optical sheet composed of a single layer of a transparent base material and having unevenness on the surface of the transparent base material can be obtained. When a curable resin composition (thermosetting resin composition or ionizing radiation curable resin composition) is used as the material to be poured into the mold, it is preferable to harden the curable resin composition before being taken out from the mold. In terms of excellent reproducibility of the concavo-convex shape, it is preferable to form the concavo-convex shape using a mold.

The formation of the concavo-convex layer by coating can be performed by applying a concavo-convex layer-forming coating solution containing a resin component and particles on a transparent substrate by a known coating method such as gravure coating and bar coating. It is formed by drying and hardening as necessary. In order for the uneven layer to satisfy the above-mentioned conditions (B1) and (B2), the film thickness of the uneven layer, the content of particles, and the average particle diameter of the particles are preferably in the following ranges.

The thickness of the uneven layer is preferably 1.0 to 10 μm, more preferably 1.5 to 5 μm, and still more preferably 1.8 to 4 μm. The thickness of the concavo-convex layer can be measured at 20 locations from an image of a cross-section captured by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), for example, and the average value of the values at the 20 locations can be measured. and calculate. The acceleration voltage of TEM or STEM is preferably set to 1-5 kV, and the magnification is preferably set to 1000-10,000 times.

Any of organic particles and inorganic particles can be used as long as the particles can form irregularities. The organic particles include polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysilicon Particles composed of oxygen, fluorine-based resin, polyester-based resin, etc. Examples of the inorganic particles include particles composed of silica, alumina, zirconia, titania, and the like. Among these particles, light-transmitting organic particles or silica particles are preferred from the viewpoint of ease of dispersion control. The above-mentioned particles may be used alone or in combination of two or more different in material and particle size.

In addition, the particles are preferably aggregates. In the case where the concavo-convex layer contains aggregates of particles, the concavities and convexities of the high-frequency components are easily maintained when a force is applied to the concavo-convex layer, while the concavities and convexities of the low-frequency components are easily deformed, and it becomes easier to satisfy the above conditions ( B1). In addition, in order to make the color unevenness of gradation difficult to be noticeable even in the case of a display device with a wide color gamut, the particles are preferably indeterminate particles having a particle diameter equal to or greater than the wavelength of visible light. The unevenness of the gradation can be suppressed by containing the irregular particles in the concavo-convex layer.

The content of the particles is preferably 4 to 25% by mass, more preferably 5 to 20% by mass, and still more preferably 5 to 15% by mass of the total solid content forming the concavo-convex layer.

The average particle diameter of the particles in the concave-convex layer varies depending on the thickness of the concave-convex layer, and therefore cannot be generalized, but from the viewpoint of easily satisfying the above-mentioned conditions (B1) and (B2), it is preferably 1.0 to 10.0 μm, and more Preferably it is 1.0-6.0 micrometers, More preferably, it is 1.0-5.0 micrometers. When the particles are aggregated, the average particle diameter of the aggregated particles preferably satisfies the above range.

The average particle diameter of the particles can be calculated by the following operations (y1) to (y3). (y1) The particle that appears to be the largest in the observation frame is selected from the images of the cross-sections captured using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). The acceleration voltage of TEM or STEM is preferably set to 1-30 kV, and the magnification is preferably set to 5000 to 300,000 times. (y2) The particles with the largest diameter appearing to be selected from the observed image, and the particle diameter of each particle is calculated. The particle size is measured in the form of the distance between the straight lines. The distance between the straight lines is when the cross section of the particle is clamped by any two parallel straight lines. If the distance between the two straight lines becomes the largest in the combination of the two straight lines. distance. (y3) The same operation was performed on the observation image of the other screen of the same sample, and the value obtained from the number average of the particle diameters of a total of 20 pieces was set as the average particle diameter of the particles. In addition, in the case of agglomerated particles, the largest diameter portion of the agglomerates is regarded as the particle size.

From the viewpoint that the concavo-convex layer easily satisfies the above-mentioned conditions (B1) and (B2), the film thickness of the concavo-convex layer is preferably larger than the average particle diameter of the particles. Moreover, more specifically, the ratio of [average particle diameter of particle]/[film thickness of uneven|corrugated layer] becomes like this. Preferably it is 0.20-0.99, More preferably, it is 0.50-0.90. The particles can also be those with a wide particle size distribution (single particle with a wide particle size distribution, or a mixture of two or more particles with different particle size distributions and a wide particle size distribution), from the viewpoint of suppressing glare In terms of particle size distribution, a narrower particle size distribution is preferred.

The resin component of the concavo-convex layer preferably contains a thermosetting resin composition or an ionizing radiation curable resin composition, and more preferably contains an ionizing radiation curable resin composition from the viewpoint of improving mechanical strength, wherein , and further preferably contains an ultraviolet curable resin composition.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition hardened by heating. As a thermosetting resin, an acrylic resin, a urethane resin, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, a silicone resin, etc. are mentioned. In the thermosetting resin composition, if necessary, a curing agent is added to these curable resins.

The ionizing radiation curable resin composition is a composition containing a compound having a ionizing radiation curable functional group (hereinafter, also referred to as "ion radiation curable compound"). Examples of free radiation curable functional groups include ethylenically unsaturated bonding groups such as (meth)acryloyl groups, vinyl groups, and allyl groups, epoxy groups, oxetanyl groups, and the like. The ionized radiation curable compound is preferably a compound having an ethylenically unsaturated bond group, more preferably a compound having two or more ethylenically unsaturated bond groups, and still more preferably a compound having two or more ethylenically unsaturated bond groups A polyfunctional (meth)acrylate-based compound of an ethylenically unsaturated bond group. As the polyfunctional (meth)acrylate-based compound, both monomers and oligomers can be used. Furthermore, the so-called ionizing radiation refers to electromagnetic waves or charged particle beams with energy quanta that can polymerize or cross-link molecules, usually ultraviolet (UV) or electron beam (EB), in addition, X-rays, Electromagnetic waves such as gamma rays; charged particle beams such as alpha rays and ion beams.

Among the polyfunctional (meth)acrylate-based compounds, the bifunctional (meth)acrylate-based monomers include ethylene glycol di(meth)acrylate and bisphenol A tetraethoxy diacrylate , bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, dicyclopentenyl di(meth)acrylate, triethylene glycol diacrylate, tetraethylene glycol di( Meth)acrylate, tricyclodecanediyl dimethylene di(meth)acrylate, tris(2-hydroxyethyl)trimeric isocyanate di(meth)acrylate, and the like. Trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, neotaerythritol can be mentioned as a trifunctional or more than trifunctional (meth)acrylate type monomer, for example Tri(meth)acrylate, neotaerythritol tetra(meth)acrylate, neotaerythritol hexa(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, dipivale Tetraol Hexa (meth)acrylate, Dipivalerythritol Penta (meth)acrylate, Dipivalerythritol Tetra (meth)acrylate, Di-trimethylolpropane Tetra (meth)acrylate , Tris (2-hydroxyethyl) trimeric isocyanate tri (meth) acrylate, etc. In addition, the above-mentioned (meth)acrylate-based monomer may be a part of which the molecular skeleton is modified, and may also be used in the form of ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, Cyclic alkyl, aromatic, bisphenol, etc. are modified.

Moreover, as a polyfunctional (meth)acrylate type oligomer, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, Acrylate-based polymers such as meth)acrylates and the like. The amine ester (meth)acrylate can be obtained, for example, by the reaction of a polyol and an organic diisocyanate with a hydroxy (meth)acrylate. In addition, preferable epoxy (meth)acrylate is (meth)acrylic acid obtained by reacting trifunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with (meth)acrylic acid. base) acrylate; (meth)acrylate obtained by reacting aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with 2 or more functions with polybasic acids and (meth)acrylic acid; And the (meth)acrylate obtained by making a bifunctional or more aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, etc. react with a phenol and (meth)acrylic acid. The above-mentioned ionizing radiation curable compounds may be used alone or in combination of two or more.

類等中之1種以上。 上述光聚合起始劑中，較佳為適當選擇雙(2,4,6－三甲基苯甲醯基)－苯基氧化膦、寡(2－羥基－2－甲基－1－[4－(1－甲基乙烯基)苯基]丙酮、2－羥基－2－甲基－1－苯基－丙烷－1－酮、1－羥基－環己基－苯基－酮、及2－甲基－1－(4－甲基噻吩基)－2－N-

啉基丙烷－1－酮中之1種或複數種。When the ionized radiation curable compound is an ultraviolet curable compound, the ionized radiation curable composition preferably contains additives such as a photopolymerization initiator or a photopolymerization accelerator. Examples of the photopolymerization initiator include those selected from the group consisting of acetophenone, benzophenone, α-hydroxyalkylphenone, α-aminoalkylphenone, α-hydroxyketone, Michler's ketone, benzoin, Acetophenone methyl ketal, benzalyl benzoate, α-acyl oxime ester, acyl phosphine oxides, 9-oxysulfur 𠮿

1 or more of the categories, etc. Among the above-mentioned photopolymerization initiators, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, oligo(2-hydroxy-2-methyl-1-[4] -(1-Methylvinyl)phenyl]acetone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-one, and 2-methyl base-1-(4-methylthienyl)-2-N-

One or more of olinylpropane-1-ones.

The photopolymerization initiator is not limited to the above-mentioned compounds, and any one may be used as long as it has the ability to initiate polymerization by ultraviolet rays. These photopolymerization initiators may be used alone or in combination of two or more. The content of the photopolymerization initiator in the ionized radiation curable resin composition is not particularly limited, but is preferably used within the range of 1 to 20 parts by mass relative to 100 parts by mass of the total amount of the ultraviolet curable compound. When using a plurality of types, it is preferable to use each within the above-mentioned range.

The photopolymerization initiator preferably has a melting point of 100°C or higher. By setting the melting point of the photopolymerization initiator to be 100°C or higher, the photopolymerization initiator remaining due to the heat during the formation of the transparent conductive film of the touch panel or the crystallization process sublimates, thereby preventing damage to the transparent conductive film. of low resistance. In addition, the photopolymerization accelerator can reduce the polymerization inhibition by air at the time of curing and accelerate the curing speed, for example, one selected from the group consisting of isoamyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate One or more of esters and the like.

Moreover, it is preferable that the uneven|corrugated layer forming coating liquid contains a leveling agent. As a leveling agent, a fluorine type leveling agent, a polysiloxane type leveling agent, a fluorine polysiloxane copolymer type leveling agent etc. are mentioned, for example. Among them, a polysiloxane-based leveling agent can be preferably used from the viewpoint of easily satisfying the above-mentioned conditions (B1) and (B2) for the uneven layer. Moreover, compared with reactive ones, non-reactive ones tend to have favorable touch panel operability. The addition amount of the leveling agent is preferably 0.01 to 5.0% by weight with respect to the total solid content of the uneven layer.

The unevenness of the optical sheet is preferably formed by antifouling treatment. By performing the antifouling treatment, the surface shape of the embodiment B can be prevented from being damaged by the stains remaining in the unevenness. In addition, the antifouling treatment using a fluorine-based mold release agent, a polysiloxane-based mold release agent, or the like imparts slidability to irregularities, easily satisfying the above-mentioned condition (B1), and making the workability more favorable. good. As a means of antifouling treatment, a means of making the uneven layer contain a release agent such as a fluorine-based mold release agent and a polysiloxane-based mold release agent, and forming a mold release layer on the outermost surface of the optical sheet with the above-mentioned mold release agent can be mentioned. the means. When the concavo-convex layer contains a mold release agent, the content of the mold release agent is preferably 0.5 to 5.0 mass % of the total solid content of the concavo-convex layer.

(transparent substrate) As a transparent base material used for an optical sheet, what has light transmittance, smoothness, heat resistance, and is excellent in mechanical strength is preferable. Examples of such transparent substrates include polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether, polyether, Polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane and amorphous olefin (Cyclo-Olefin- Polymer: COP) and other plastic films. The transparent substrate can also be formed by laminating two or more plastic films. In addition, in addition to the above-mentioned plastic films manufactured by general methods such as extrusion molding (inflation method, T-die method) or solution casting method: solution casting, calendering method: calendaring, etc. A coating film made of resin such as an ionizing radiation curable resin composition is formed on a base material having releasability, and the film is produced by peeling the coating film from the base material.

Among the above, from the viewpoint of mechanical strength and dimensional stability, polyesters (polyethylene terephthalate, polyethylene naphthalate) subjected to stretching, particularly biaxial stretching, are preferred. In addition, COP and polyester are preferable in that they are excellent in weather resistance.

The thickness of the transparent substrate is preferably 5-300 μm, more preferably 10-200 μm, and still more preferably 20-130 μm. In order to improve the adhesiveness, the surface of the transparent substrate can be subjected to physical treatment such as corona discharge treatment and oxidation treatment in advance. In addition, a paint called a tackifier or a primer can also be applied in advance.

The transparent substrate preferably has a retardation value exceeding 0 nm and less than 3,000 nm, more preferably exceeding 20 nm and less than 2,000 nm. The retardation value is set to a value at a wavelength of 550 nm. The retardation value of the transparent substrate is determined by the following formula, and is determined by the refractive index _nx in the direction of the in-plane refractive index of the transparent substrate that is the largest in the direction of the retardation axis, the in-plane direction of the transparent substrate and the direction of the retardation axis. The orthogonal direction is represented by the refractive index _ny in the direction of the advance axis and the thickness d of the transparent substrate. Retardation value (Re)=( _nx - _ny )×d The above-mentioned retardation value can be measured by, for example, the trade names “KOBRA-WR” and “PAM-UHR100” manufactured by Oji Scientific Instruments.

Usually, when a transparent substrate with a small retardation value is used, the color unevenness of the gradient color generated by the light passing through the transparent substrate is observed (for example, through polarized sunglasses, a transparent material with a specific retardation value is recognized through a polarizing plate. observed in the light of the substrate). However, since the optical sheet used in the touch panel of Embodiment B satisfies the condition (B2), even if a transparent base material with a small retardation value is used, the color unevenness of the gradation can be hardly noticeable. Furthermore, even if the retardation value is reduced, the fact that the color unevenness of the gradation can be made inconspicuous is related to the thinning of the base material thickness of the transparent base material. That is, with regard to a transparent substrate (for example, a polyester film that is a general-purpose substrate) that generates retardation, generally, by performing uniaxial stretching to increase the thickness of the substrate, etc., the retardation value is increased, thereby suppressing the Produces uneven color gradients. However, with regard to the optical sheet used in the touch panel of the embodiment B, even if the thickness of the transparent substrate (for example, a polyester film as a general substrate) is reduced, the color unevenness of the gradation can be caused Hard to notice. Furthermore, even if the retardation value is made small, the case where the uneven color of the gradation can be made less noticeable is related to the situation that it is usually possible to use the color unevenness of the gradation, which is easy to produce, and it is beyond the scope of choice. Plastic film (polyimide film, polyaramide film). A polyimide film and a polyaramide film are preferable in that they are excellent in flexibility resistance. In recent years, the color gamut of display elements tends to expand. A display element with a wide color gamut has a steep shape in the spectral spectrum of each color (R, G, B). For such a display element, the color unevenness of the gradation specific to the retardation value tends to be particularly noticeable. Regarding the optical sheet used in the touch panel of the embodiment B, it is preferable in that even in a display element with a wide color gamut, the color unevenness of the gradation can be made inconspicuous.

The optical sheet may also have functional layers such as an antireflection layer, an antifouling layer, and an antistatic layer on the concavo-convex and/or the surface opposite to the concavo-convex. Moreover, when there exists a structure of an uneven|corrugated layer on a transparent base material, in addition to the said part, you may have a functional layer between a transparent base material and an uneven|corrugated layer. Furthermore, when other functional layers are laminated on the concavo-convex layer, the concavo-convex on the outermost surface satisfies the scope of this case. The concavo-convex may be a single layer or a plurality of layers as long as the outermost surface is within the scope of the present invention.

The touch panel of Embodiment B is provided with outdoor anti-glare properties by the uneven shape of the optical sheet, and is excellent in operability. In addition, the reduction in resolution can be suppressed. Therefore, the touch panel of the embodiment B is preferably installed on the output surface side of the display element of a display device for in-vehicle use, a smartphone or a tablet (multifunctional mobile terminal) carried when moving, such as a train.

[display device] The display device of Embodiment B has concavities and convexities on the outermost surface of the output surface side of the display element, and the concavities and convexities satisfy the above-mentioned conditions (B1) and (B2). The display device of Embodiment B can use the same optical sheet as the optical sheet used in the touch panel of Embodiment B described above as a member having irregularities on the outermost surface.

As a display element, a liquid crystal display element, an in-cell touch panel liquid crystal display element, an EL display element, a plasma display element, etc. are mentioned. Furthermore, the liquid crystal display element has a backlight device on the back of the liquid crystal element. The in-cell touch panel liquid crystal element is a liquid crystal element formed by sandwiching liquid crystals between two glass substrates and has touch panel functions such as resistive film type, electrostatic capacitance type, and optical type. In addition, as a display method of the liquid crystal of an in-cell touch panel liquid crystal element, an IPS method, a VA method, a multi-domain method, an OCB method, an STN method, a TSTN method, etc. are mentioned. The in-cell touch panel liquid crystal element is described in, for example, Japanese Patent Laid-Open No. 2011-76602 and Japanese Patent Laid-Open No. 2011-222009.

The optical sheet can be provided on the output surface side of the display element, for example, in the following order. (a) Display element/surface protection sheet/optical sheet (b) Display element/optical sheet (c) Touch panel with display element/optical sheet on top In the case of (a) and (b), outdoor anti-glare properties can be imparted to the display device by arranging the unevenness of the optical sheet toward the opposite side to the display element. In addition, the reduction in the resolution of the display element can be suppressed, and the scratches generated on the surface or the display element can be made difficult to see. In the case of (c), the display device becomes a display device with a touch panel provided with a touch panel having an optical sheet on the uppermost part on the output surface side of the display element. In this case, a display device excellent in outdoor anti-glare property, high resolution, and operability of the touch panel can be produced. Therefore, the display device of Embodiment B is preferably used as a display device for in-vehicle use, a smartphone or a tablet (multifunctional mobile terminal) that is carried when moving in a train or the like.

As described above, with regard to the optical sheet used in the display device of Embodiment B, even for a display element with a wide color gamut, the color unevenness of the gradation can be hardly noticeable. As a standard for expressing color gamut, "ITU-R recommends BT.2020 (hereinafter, referred to as "BT.2020")" and the like. ITU-R is the abbreviation of "International Telecommunication Union-Radiocommunication Sector", and ITU-R advises BT.2020 to be the international standard for the color gamut of high-definition television. Regarding the display device of the embodiment B, even for a display element with a coverage rate of 60% or more based on the CIE-xy chromaticity diagram of the BT.2020 represented by the following formula, the color unevenness of the gradation is difficult to attract. Attention. ＜Formula representing the coverage of BT.2020＞ [In the area of the CIE-xy chromaticity diagram of the display element, the area that overlaps with the area of the CIE-xy chromaticity diagram of BT.2020 / the area of the CIE-xy chromaticity diagram of BT.2020] × 100 (%)

Furthermore, the "area of the CIE-xy chromaticity diagram" necessary to calculate the coverage of BT.2020 is to measure the CIE- The x-value and y-value of the Yxy color system can be obtained from the "red (R) vertex coordinates", "green (G) vertex coordinates" and "blue (B) vertex coordinates" obtained from the measurement results "Calculate. The x value and the y value of the CIE-Yxy colorimetric system can be measured, for example, with a spectroradiometer CS-2000 manufactured by Konica Minolta. Examples of display elements with a wide color gamut include: three-color independent organic EL display devices (among them, three-color independent organic EL elements with a microcavity structure), liquid crystal display elements using quantum dots for backlight devices, backlight devices The device uses a liquid crystal display element such as a white LED (near-ultraviolet LED, a combination of a blue phosphor, a green phosphor, and a red phosphor) of a three-wavelength method.

[Optical sheet] The optical sheet of Embodiment B has unevenness|corrugation on one surface, and this unevenness|corrugation satisfies the said conditions (B1) and (B2). Furthermore, in the optical sheet of Embodiment B, when other functional layers are laminated on the above-mentioned unevenness, the unevenness of the outermost surface satisfies the scope of the present application. The concavo-convex may be a single layer or a plurality of layers as long as the outermost surface is within the scope of the present invention. As an optical sheet of Embodiment B, the same optical sheet used for the touch panel of Embodiment B mentioned above is mentioned.

When using the optical sheet of Embodiment B for a touch panel, this optical sheet is provided so that the surface which has unevenness|corrugation becomes the surface of the operator side of a touch panel. In order to satisfy the above-mentioned conditions (B1) and (B2), the optical sheet of the embodiment B is provided on the uppermost part of the touch panel, thereby imparting outdoor anti-glare properties to the touch panel, and making the touch panel The operability becomes excellent. Therefore, the optical sheet of the embodiment B can be preferably used for the surface of a display device for in-vehicle use, and the surface of a smartphone or tablet (multifunctional mobile terminal) carried when a train or the like moves.

[Screening method of optical sheet] The screening method of the optical sheet of Embodiment B is to select the optical sheet having concavities and convexities on one side, the concavities and convexities satisfying the above-mentioned conditions (B1) and (B2) as the optical sheet located on the uppermost part of the touch panel.

In the screening method of the optical sheet of the embodiment B, even if the workability test of the optical sheet is not carried out, the optical sheet with good workability, outdoor anti-glare property and high resolution can be screened efficiently. Product design and quality management of optical sheets.

Regarding the judgment conditions for screening the optical sheet of the touch panel, the above-mentioned conditions (B1) and (B2) are set as necessary conditions. Regarding the determination condition of the condition (B1), for example, the ratio (μs/μk) when the load is 50 to 150 g is preferably in the range of 1.6 to 2.5, more preferably in the range of 1.7 to 2.2. In addition, when the load is 900 to 1100 g, the ratio (μs/μk) is preferably in the range of 1.0 to 1.5, more preferably in the range of 1.1 to 1.4. In addition, the determination condition of the condition (B2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, more preferably 0.25 μm≦Ra _2.5 ≦0.55 μm, and more preferably 0.30 μm≦Ra _2.5 ≦0.50 μm.

Regarding the screening method of the optical sheet of a touch panel, from the viewpoint of excellent operability and outdoor anti-glare property, it is further preferable to set the following condition (B3) as a newly added determination condition. Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦3.2 (B3) The determination condition of the condition (B3) is preferably the preferable numerical range of the optical sheet of the above-mentioned Embodiment B. Furthermore, other parameters are preferably set as the newly added determination conditions. [Example]

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to the aspect described in an Example. In addition, "part" and "%" are used as quality standards unless otherwise specified.

<Example of Embodiment A> A1. Measurement and Evaluation The following measurement and evaluation were performed about the optical sheet produced in the Example and the comparative example. The results are shown in Table 1.

A1-1. Coefficient of static friction Using HEIDON HHS2000 manufactured by Xindong Science Co., Ltd., measure the coefficient of static friction by the following method under a certain load reciprocating friction measurement mode. The sapphire needle with a radius of 0.3 mm at the front end was made to vertically contact the unevenness of the optical sheet, and a vertical load of 100 g was applied to the squeegee, and at the same time, the squeegee was made to scan at a speed of 10 mm/s for a single pass with a length of 10 mm. The reciprocation was performed once, and this time was measured as the static friction coefficient (μs10) of the squeegee. Moreover, the static friction coefficient (μs ₂₀ ) when the scanning speed was set to 20 mm/sec was measured. Furthermore, the atmosphere during measurement is set to a temperature of 23°C±5°C and a humidity of 50%±10%. In addition, each sample was placed in an atmosphere of 23° C.±5° C. and a humidity of 50%±10% for 10 minutes or more before starting the measurement.

A1-2. Surface roughness measurement (cutoff value 2.5 mm) The optical sheets of Examples and Comparative Examples were cut into 10 cm squares. The cut site was selected from a random site after confirming visually that there were no abnormal points such as dust or damage. Prepare to attach the cut surface member to a black board with a size of 10 cm in length × 10 cm in width (manufactured by Kuraray Co., Ltd., trade name : Comoglas Product No.: DFA502K, thickness 2.0 mm) with 20 samples each. Using a surface roughness measuring instrument (model: SE-3400 / manufactured by Kosaka Laboratory Co., Ltd.), after setting the sample in a state where the sample is fixed and in close contact with the measurement platform, the unevenness of the optical sheet is measured according to the following measurement conditions. Ra, Rz, S, and Sm of JIS B0601:1994. The calculation of θa is based on the operating instructions (revised on July 20, 1995) of the surface roughness measuring instrument (SE-3400) manufactured by Kosaka Research Institute. The average value of 20 samples was taken as Ra, Rz, S, Sm, and θa of each Example and Comparative Example. The atmosphere during measurement is set to a temperature of 23°C±5°C and a humidity of 50%±10%. In addition, before starting the measurement, each sample was left to stand for 10 minutes or more in an atmosphere of 23°C±5°C and a humidity of 50%±10%. [Stylus of Surface Roughness Detection Section] Trade name SE2555N manufactured by Kosaka Laboratory Co., Ltd. (Front end curvature radius: 2 μm, vertex angle: 90 degrees, material: diamond) [Measuring conditions of surface roughness measuring instrument] ・Reference length (cutoff value λc of roughness curve): 2.5 mm ・Evaluation length (reference length (cutoff value λc) × 5): 12.5 mm ・Conveying speed of stylus: 0.5 mm/s ・Vertical magnification: 2000 times ・Lateral magnification: 10 times ・Skid: Not used (not in contact with the measurement surface) ・Cutoff filter type: Gaussian ・Insensitive zone level: 10% ・tp/PC curve: normal

A1-3. Surface roughness measurement (cutoff value 0.8mm) Using a surface roughness measuring instrument (model: SE-3400/manufactured by Kosaka Laboratory Co., Ltd.), Rz of JIS B0601:1994 of the uneven surfaces of the 20 samples described above was measured under the following measurement conditions. The average value of 20 samples was taken as the Rz of each Example and Comparative Example. [Stylus of Surface Roughness Detection Section] Trade name SE2555N manufactured by Kosaka Laboratory Co., Ltd. (Front end curvature radius: 2 μm, vertex angle: 90 degrees, material: diamond) [Measuring conditions of surface roughness measuring instrument] ・Reference length (cutoff value λc of roughness curve): 0.8 mm ・Evaluation length (reference length (cutoff value λc) × 5): 4.0 mm ・Conveying speed of stylus: 0.5 mm/s ・Vertical magnification: 2000 times ・Lateral magnification: 10 times ・Slide: Not used (not in contact with the measurement surface) ・Cutoff filter type: Gaussian ・Insensitive zone level: 10% ・tp/PC curve: normal

A1-4. Outdoor anti-glare A black acrylic plate was bonded to the base material side of the obtained optical sheet via a transparent adhesive, and the sample for evaluation was produced. Next, in an environment with an illuminance of 7,000 to 13,000 lux (the environment in front of the window on a sunny day), each sample for evaluation was set horizontally on a water platform with a height of about 1 m, and 20 people were visually inspected from a height of about 50 cm above. The evaluations were performed from various angles, and the evaluations were performed according to the following criteria, and the most evaluations were used as the results. A: No glare of sunlight is felt on the surface of the sample. B: The viewing angle is slightly dazzling from the sunlight on the surface of the sample, but it is within the allowable range. C: The glare of sunlight is strongly felt on the sample surface.

A1-5. Resolution The substrate side of the obtained optical sheet was pasted on the outermost glass of a commercial mobile phone (7.9-inch LCD) through a transparent adhesive, and the illuminance was 7000-13000 lux (in front of the window on a sunny day) , each display device was set horizontally on a water platform with a height of about 1 m, and 20 people visually checked the icons and characters of the initial screen of each display device from about 30 cm above at various angles. 2 points were assigned to those who could recognize the icons and characters well; 1 point was assigned to those who could recognize the icons and characters within the range that would not interfere with the operation; points for evaluation. The average score of 20 people is 1.6 points or more as A, those who will be more than 1.2 points and less than 1.6 points as B, and those less than 1.2 points as C.

A1-6. Touch (Sliding) A 10 cm square acrylic plate was attached to the base material side of the obtained optical sheet. Next, the following two kinds of operations, which are supposed to be operated with the touch panel, are performed. This operation was performed by 20 persons, and evaluation was performed by assigning an extremely favorable tactile sensation to 2 points, a good tactile sensation to 1 point, and a poor tactile sensation to 0 points. The average score of 20 people is 1.6 points or more as A, 1.2 points or more and less than 1.6 points as B, and less than 1.2 points as C. <Operation 1 (scroll operation)> Operate with the pulp of your index finger. Carry out the following operations: Press the board with the dominant hand, and move the finger pulp of the non-dominant hand on the uneven surface of the optical sheet for about 5 cm in the left-right direction for about 1 second. This operation 1 was repeated 5 times. <Operation 2 (enlargement/reduction operation)> Press the board with the dominant hand, place the lateral sides of the index finger and thumb of the non-dominant hand on the approximate center of the uneven surface of the optical sheet, and move the index finger and thumb by 2 to 3 cm at the same time for about 1 second to expand. time operation. Immediately after that, the operation for shrinking to the original center is performed. This operation 2 was repeated 5 times.

A1-7. The tactile feeling of the finger at the beginning of the operation The same sample as the above (A1-6) was prepared, and 20 people performed the operations of the above 1 and the above 2. In operation 1 and operation 2, those with the same degree of stuttering of the fingers were set as 2 points, those with slightly different degrees of stuttering of the fingers were set as 1 point, and those with different degrees of stuttering of the fingers were set as 0 points for evaluation. . The average score of 20 people is 1.6 points or more as A, 1.2 points or more and less than 1.6 points as B, and less than 1.2 points as C.

A2. Fabrication of optical sheet [Example A1] Coating the concave-convex layer coating solution A1 of the following formula on a plastic film (thickness 80 μm triacetyl cellulose resin film (TAC), manufactured by Fujifilm, TD80UL), After drying for 30 seconds at 70°C and a wind speed of 5 m/s, ultraviolet rays were irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the cumulative light intensity was 100 mJ/cm ² to form a concavo-convex layer to obtain an optical sheet. The thickness of the uneven layer was 7 μm.

<Concavo-convex layer coating solution A1> ・Di-trimethylolpropane tetraacrylate 55 parts (manufactured by SARTOMER, SR355) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure 184) ・0.25 part of polysiloxane-based leveling agent (Made by Momentive Performance Materials, TSF4460) ・Spherical polyacrylic acid-styrene copolymer particles 10 parts (average particle size 6 μm, refractive index 1.52) ・Colloidal silica fine particles (reactive hydrophobic treatment) 100 parts (manufactured by Nissan Chemical Industries, Ltd., solvent MIBK, solid content 30%) (average particle size 10-15 nm) ・Solvent (MIBK) 110 parts

[Example A2] An optical sheet was obtained in the same manner as in Example A1 except that the uneven layer coating liquid A1 of Example A1 was changed to the uneven layer coating liquid A2 of the following formulation, and the film thickness was 6 μm. <Concavo-convex layer coating solution A2> ・Multifunctional acrylate oligomer 60 parts (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UV7640B functional group number 6～7) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure 184) ・Polysiloxane-based leveling agent: 0.2 part of polyester modified polydimethylsiloxane (Made by BYK-CHEMIE, BYK370) ・Spherical polyacrylic acid-styrene copolymer particles 16 parts (average particle size 3.5 μm, refractive index 1.52) ・Fumed silica fine particles (hydrophobic treatment: octylsilane treatment) 6 parts (manufactured by Airlogi, Japan, with an average particle size of 10-15 nm) ・Solvent 1 (toluene) 135 parts

[Example A3] Optical fiber was obtained in the same manner as in Example A1, except that the coating solution A1 for the concavo-convex layer of Example A1 was changed to the coating solution A3 for the concavo-convex layer of the following formulation, and the thickness of the concavo-convex layer was set to 2.5 μm. piece. <Concavo-convex layer coating solution A3> ・Neotaerythritol triacrylate 100 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・14 parts of inorganic particles (Amorphous silica manufactured by Fuji Silesia Chemical Co., Ltd.) (hydrophobic treatment, silane coupling agent, average aggregate particle size 2 μm) ・Photopolymerization initiator 5 parts (manufactured by BASF Corporation, Irgacure 184) ・0.2 part of polysiloxane-based leveling agent (Manufactured by Momentive Performance Materials TSF4460) ・Mold release agent 2 parts (Daikin Industrial Co., Ltd., OPTOOL DAC) ・Solvent 1 (toluene) 150 parts ・Solvent 2 (MIBK) 35 parts

[Comparative Example A1] Optical fiber was obtained in the same manner as in Example A1, except that the coating solution A1 for the concavo-convex layer of Example A1 was changed to the coating solution A4 for the concavo-convex layer of the following formulation, and the thickness of the concavo-convex layer was set to 4 μm. piece. <Concavo-convex layer coating solution A4> ・Aliphatic polyester skeleton 6-functional urethane acrylate 100 parts (manufactured by SARTOMER, CN968) ・3 parts of spherical polyacrylic acid-styrene copolymer particles (average particle size 2.5 μm, refractive index 1.52) ・Silica fine particles (hydrophobic treatment: methyl) 3 parts (manufactured by Airlogi, Japan, with an average particle size of 10-15 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.2 part of polyether-modified polysiloxane (manufactured by Shin-Etsu Silicones, KF6004) ・Solvent 1 (toluene) 150 parts ・Solvent 2 (MIBK) 35 parts

[Comparative Example A2] An optical fiber was obtained in the same manner as in Example A1, except that the coating solution A1 for the concavo-convex layer of Example A1 was changed to the coating solution A5 for the concavo-convex layer of the following formulation, and the thickness of the concavo-convex layer was set to 3 μm. piece. <Concavo-convex layer coating solution A5> ・Aliphatic polyester skeleton 6-functional urethane acrylate 100 parts (manufactured by SARTOMER, CN968) ・Amorphous silica fine particles (hydrophobic treatment: silane coupling agent) 15 parts (manufactured by Fuji Silesia Chemical Co., Ltd., with an average aggregate particle size of 2.5 μm) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.2 part of polyether-modified polysiloxane (manufactured by Shin-Etsu Silicones Co., Ltd., X-22-2516) ・Solvent (toluene) 150 parts

[Table 1] Table 1 Example A1 Example A2 Example A3 Comparative Example A1 Comparative Example A2 Static friction coefficient μs ₁₀ 0.14 0.16 0.16 0.13 0.36 μs ₂₀ 0.13 0.15 0.24 0.25 0.35 μs ₂₀ / μs ₁₀ 0.93 0.94 1.50 1.92 0.97 surface shape Ra _2.5 (μm) 0.18 0.16 0.47 0.08 0.72 Rz _2.5 (μm) 1.51 1.11 3.54 0.43 4.49 Rz _2.5 /Ra _2.5 8.5 7.2 7.5 5.6 6.2 S _2.5 (μm) 53.5 35.3 49.0 74.6 35.4 θa _2.5 (°) 1.4 1.4 3.6 0.3 6.3 Ry _2.5 (μm) 2.0 1.4 4.3 0.5 5.2 Sm _2.5 (μm) 141 108 123 163 89 Rz _0.8 (μm) 1.20 0.86 2.61 0.34 3.82 Rz _2.5 - Rz _0.8 (μm) 0.31 0.25 0.93 0.09 0.67 Rz _2.5 /Rz _0.8 1.26 1.29 1.36 1.27 1.17 Ry _2.5 /Rz _2.5 1.32 1.26 1.21 1.16 1.16 θa _2.5 / (Ry _2.5 /Rz _2.5 ) 1.06 1.11 2.98 0.26 5.43 Outdoor anti-glare B B A C A Analytical A A B A C touch slidability A A B C A operability The tactile feeling of the finger at the beginning of the operation A A B C A

From the results in Table 1, it is understood that the optical sheets of Examples A1 to A3 can provide outdoor anti-glare properties, and can also provide good resolution and workability.

A3. Fabrication of touch panel An ITO conductive film with a thickness of 20 nm was formed by sputtering on the transparent substrate side of the optical sheets of Examples A1 to A3 and Comparative Examples A1 and A2, and the upper electrode plate was produced. Next, an ITO conductive film with a thickness of about 20 nm was formed by sputtering on one surface of a tempered glass plate with a thickness of 1 mm, thereby producing a lower electrode plate. Next, by the screen printing method, the ionized radiation curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as the coating liquid for spacers was dot-printed on the surface of the lower electrode plate having the conductive film, and then a high pressure A mercury lamp was irradiated with ultraviolet rays, and spacers with a diameter of 50 μm and a height of 8 μm were arranged at 1 mm intervals. Next, the upper electrode plate and the lower electrode plate were arranged so that the conductive films faced each other, and the edges were adhered with a double-sided tape having a thickness of 30 μm and a width of 3 mm to prepare Examples A1 to A3 and Comparative Examples. A1, A2 resistive film touch panel. The resistive film touch panels of Examples A1 to A3 have outdoor anti-glare properties, and are good in resolution and operability. On the other hand, the resistive film touch panel of Comparative Example A1 was dazzling due to insufficient outdoor anti-glare property, and the operability was lowered. In addition, the resistive film touch panel of Comparative Example A2 cannot recognize the image and text information of the display screen due to excessive outdoor anti-glare properties.

A4. Fabrication of display device (1) The optical sheets of Examples A1 to A3 and Comparative Examples A1 and A2 were bonded to the surface glass plate of a commercially available ultra-high-definition liquid crystal display device (4.7 inches, pixel density of about 320 ppi) through a transparent adhesive, and the production was carried out. The display devices (1) of Examples A1 to A3 and Comparative Examples A1 and A2. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the opposite side to the display element. The obtained display devices (1) were visually evaluated for the presence or absence of glare. As a result, the display devices (1) of Examples A1 to A3 had suppressed glare and little reflection of external light, resulting in good visibility. In addition, the display devices (1) of the embodiments A1 to A3 also do not impair the resolution of the ultra-high-definition images.

A5. Fabrication of display device (2) Except that the substrates of the optical sheets of Examples A1 to A3 and Comparative Examples A1 and A2 were changed to polyethylene terephthalate films with a thickness of 50 μm (retardation value of 2,500 nm), the same as those of Examples A1 to A3. In the same manner as Comparative Examples A1 and A2, optical sheets of Examples A4 to A6 and Comparative Examples A3 and A4 were produced. The physical property values of Table 1 of the optical sheets of Examples A4 to A6 and Comparative Examples A3 and A4 are substantially the same as those of Examples A1 to A3 and Comparative Examples A1 and A2. The optical sheets of Examples A4 to A6 and Comparative Examples A3 and A4, and the organic EL display element of the three-color independent mode with a microcavity structure, a commercially available organic EL display device with a polarizing element (based on the CIE-xy chromaticity diagram) Coverage of BT.2020: 77%) of the surface glass plates were pasted through a transparent adhesive, and the display devices (2) of Examples A4 to A6 and Comparative Examples A3 and A4 were produced. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the opposite side to the display element.

[Evaluation of Display Device (2)] ＜Color unevenness in gradation＞ The screen of the display device (2) is displayed in white or substantially white. The screen was visually observed through polarized sunglasses from various angles, and according to the following criteria, 20 people evaluated whether the color unevenness of the gradation was recognizable, and the evaluation with the largest number was set as the result. The results are shown in Table 2. A: The color unevenness of the gradation color cannot be recognized. B: The color irregularity of the gradation color is barely discernible, but does not impair the image quality. C: The color unevenness of the gradation is clearly recognized, which seriously hinders the image quality.

The display elements constituting the display device (2) have a very wide color gamut and are prone to uneven color gradation, but the display devices of Examples A4 to A6 can hardly recognize the uneven color of the gradation. In particular, since the display device of Example A6 has a large Ra and a moderately irregular concave-convex shape, the color unevenness of the gradation is almost completely unrecognizable.

[Table 2] Table 2 Example A4 Example A5 Example A6 Comparative Example A3 Comparative Example A4 uneven color B B A C B

<Example of Embodiment B> B1. Measurement and Evaluation The following measurement and evaluation were performed about the optical sheet produced in the Example and the comparative example. The results are shown in Table 3.

B1-1. Friction coefficient Using the trade name HEIDON NHS2000 manufactured by Xindong Science Co., Ltd., the static friction coefficient μs and the dynamic friction coefficient μk are measured by the following method under a certain load reciprocating friction measurement mode, and the ratio (μs/μk) is calculated. A sapphire needle with a radius of 0.3 mm at the front end was made to vertically contact the unevenness of the optical sheet, and a vertical load of 100 g was applied to the squeegee, and at the same time, the squeegee was made to scan at a speed of 5 mm/s for a single pass with a length of 10 mm. The reciprocation was performed once, and the kinetic friction coefficient μk of the scraper needle was measured at this time. Furthermore, by the same operation, the coefficient of kinetic friction μk was measured when the vertical loads applied to the squeegee were 500 g and 1000 g. Furthermore, in the same manner as the above-mentioned operation, the static friction coefficient μs when the vertical load applied to the squeegee was 100 g, 500 g, and 1000 g was measured. Furthermore, the atmosphere during measurement is set to a temperature of 23°C±5°C and a humidity of 50%±10%. In addition, each sample was placed in an atmosphere of 23° C.±5° C. and a humidity of 50%±10% for 10 minutes or more before starting the measurement. The equations of Examples B1, B2, and Comparative Example B4 shown in Table 3 are all approximate first-order straight lines calculated by the least squares method.

B1-2. Surface roughness measurement (cutoff value 2.5mm) The optical sheets of Examples and Comparative Examples were cut into 10 cm squares. The cutting site is selected from a random site after confirming visually that there are no abnormal points such as dust or damage. Prepare to attach the cut surface member to a black board with a size of 10 cm in length × 10 cm in width (manufactured by Kuraray Co., Ltd., trade name : Comoglas Product No.: DFA502K, thickness 2.0 mm) with 20 samples each. Using a surface roughness measuring instrument (Model: SE-3400 / manufactured by Kosaka Laboratory Co., Ltd.), after setting the sample in a state where the sample is fixed and in close contact with the measurement platform, the unevenness of the optical sheet is measured according to the following measurement conditions. Ra, Rz, S, and Sm of JIS B0601:1994. The calculation of θa is based on the operating instructions (revised on July 20, 1995) of the surface roughness measuring instrument (SE-3400) manufactured by Kosaka Research Institute. The average value of 20 samples was taken as Ra, Rz, S, Sm, and θa of each Example and Comparative Example. The atmosphere during measurement is set to a temperature of 23°C±5°C and a humidity of 50%±10%. In addition, before starting the measurement, each sample was left to stand for 10 minutes or more in an atmosphere of 23°C±5°C and a humidity of 50%±10%. [Stylus of Surface Roughness Detection Section] Trade name SE2555N manufactured by Kosaka Laboratory Co., Ltd. (Front end curvature radius: 2 μm, vertex angle: 90 degrees, material: diamond) [Measuring conditions of surface roughness measuring instrument] ・Reference length (cutoff value λc of roughness curve): 2.5 mm ・Evaluation length (reference length (cutoff value λc) × 5): 12.5 mm ・Conveying speed of stylus: 0.5 mm/s ・Vertical magnification: 2000 times ・Lateral magnification: 10 times ・Slide: Not used (not in contact with the measurement surface) ・Cutoff filter type: Gaussian ・Insensitive zone level: 10% ・tp/PC curve: normal

B1-3. Surface roughness measurement (cutoff value 0.8 mm) Using a surface roughness measuring instrument (model: SE-3400/manufactured by Kosaka Laboratory Co., Ltd.), Rz of JIS B0601:1994 of the uneven surfaces of the 20 samples described above was measured under the following measurement conditions. The average value of 20 samples was taken as the Rz of each Example and Comparative Example. [Stylus of Surface Roughness Detection Section] Trade name SE2555N manufactured by Kosaka Laboratory Co., Ltd. (Front end curvature radius: 2 μm, vertex angle: 90 degrees, material: diamond) [Measuring conditions of surface roughness measuring instrument] ・Reference length (cutoff value λc of roughness curve): 0.8 mm ・Evaluation length (reference length (cutoff value λc) × 5): 4.0 mm ・Conveying speed of stylus: 0.5 mm/s ・Vertical magnification: 2000 times ・Lateral magnification: 10 times ・Slide: Not used (not in contact with the measurement surface) ・Cutoff filter type: Gaussian ・Insensitive zone level: 10% ・tp/PC curve: normal

B1-4. Outdoor anti-glare A black acrylic plate was bonded to the base material side of the obtained optical sheet via a transparent adhesive, and the sample for evaluation was produced. Then, under the environment of illuminance of 7,000 to 13,000 lux (in front of the window on a sunny day), each sample for evaluation was set horizontally on a water platform with a height of about 1 m, and 20 people performed visual inspection from about 50 cm above at various angles. The evaluation was performed according to the following criteria, and the evaluation with the largest number was used as the result. A: No glare of sunlight is felt on the surface of the sample. B: The viewing angle is slightly dazzling from the sunlight on the surface of the sample, but it is within the allowable range. C: The glare of sunlight is strongly felt on the sample surface.

B1-5. Analytical The substrate side of the obtained optical sheet was pasted on the outermost glass of a commercial mobile phone (7.9-inch LCD) through a transparent adhesive, and the illuminance was 7000-13000 lux (in front of the window on a sunny day) , each display device was set horizontally on a water platform with a height of about 1 m, and 20 people visually checked the icons and characters of the initial screen of each display device from about 30 cm above at various angles. 2 points were assigned to those who could recognize the icons and characters well; 1 point was assigned to those who could recognize the icons and characters within the range that would not interfere with the operation; points for evaluation. The average score of 20 people is 1.6 points or more as A, those who will be more than 1.2 points and less than 1.6 points as B, and those less than 1.2 points as C.

B1-6. Operability A sample in which a 10 cm square acrylic plate was attached to the substrate side of the obtained optical sheet was produced. Next, the operation of moving a finger on the uneven surface of the optical sheet of the sample to change the direction is performed. The operation system should be carried out under a lighter load (when standing, hold the sample with the hand opposite to the dominant hand, and use the dominant hand to operate the load), and a heavier load (place the sample on the table, use the The sample is fixed with the hand opposite to the dominant hand, and the load is carried out with the dominant hand) under two loads. When operating any kind of load, the direction can be easily changed, and those who feel good operability are rated as 2 points. When operating at least one load, the finger slides a little when the direction is changed, or the direction is changed. Those who feel the finger is slightly heavier and feel a little abnormal in operability is set as 1 point. When operating at least one load, the finger slides when the direction is changed, or the finger is heavier when the direction is changed, and the feeling is Those with obvious abnormality in operability were set as 0 points and evaluated by 20 people. The average score of 20 people is 1.6 points or more as A, those who will be 1.0 points or more but less than 1.6 points as B, those who will be 0.5 points or more but less than 1.0 points as C, and less than 0.5 points is set to D.

B-2. Fabrication of optical sheets [Example B1] Coating solution B1 for concavo-convex layer of the following formulation was applied to a plastic film (thickness 80 μm triacetate cellulose resin film (TAC), manufactured by Fujifilm, TD80UL ), dried at 70°C and a wind speed of 5 m/s for 30 seconds, and then irradiated with ultraviolet rays in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the cumulative light intensity became 100 mJ/cm ² to form a concavo-convex layer to obtain an optical sheet . The thickness of the uneven layer was 2.5 μm.

<Concavo-convex layer coating liquid B1> ・Neotaerythritol triacrylate 100 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・14 parts of inorganic particles (Amorphous silica manufactured by Fuji Silesia Chemical Co., Ltd.) (hydrophobic treatment, silane coupling agent, average aggregate particle size 2 μm) ・Photopolymerization initiator 5 parts (manufactured by BASF, Irgacure184) ・0.2 part of polysiloxane-based leveling agent (Manufactured by Momentive Performance Materials TSF4460) ・Mold release agent 2 parts (Daikin Industrial Co., Ltd., OPTOOL DAC) ・Solvent 1 (toluene) 150 parts ・Solvent 2 (MIBK) 35 parts

[Example B2] An optical fiber was obtained in the same manner as in Example B1, except that the coating solution B1 for the concavo-convex layer of Example B1 was changed to the coating solution B2 for the concavo-convex layer of the following formulation, and the thickness of the concavo-convex layer was set to 4 μm. piece. <Concavo-convex layer coating liquid B2> ・100 parts of neotaerythritol tetraacrylate (Kyoeisha Chemical Co., Ltd., Light acrylate PE-4) ・Amorphous silica particles (hydrophobic treatment: silane coupling agent) 3 parts (manufactured by Fuji Silesia Chemical Co., Ltd., with an average aggregate particle size of 3 μm) ・Amorphous silica particles (hydrophobic treatment: silane coupling agent) 3 parts (manufactured by Fuji Silesia Chemical Co., Ltd., with an average aggregate particle size of 1.5 μm) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.2 part of polyether-modified polysiloxane (manufactured by Shin-Etsu Silicones, KF6004) ・Solvent (toluene) 150 parts

[Comparative Example B1] An optical fiber was obtained in the same manner as in Example B1, except that the coating liquid B1 for the concavo-convex layer of Example B1 was changed to the coating liquid B3 for the concavo-convex layer of the following formulation, and the film thickness of the concavo-convex layer was set to 7 μm piece. <Concavo-convex layer coating liquid B3> ・Di-trimethylolpropane tetraacrylate 55 parts (manufactured by SARTOMER, SR355) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・0.25 part of polysiloxane-based leveling agent (Made by Momentive Performance Materials, TSF4460) ・Spherical polyacrylic acid-styrene copolymer particles 10 parts (average particle size 6 μm, refractive index 1.52) ・Colloidal silica fine particles (reactive hydrophobic treatment) 100 parts (manufactured by Nissan Chemical Industries, Ltd., solvent MIBK, solid content 30%) (average particle size 10-15 nm) ・Solvent (MIBK) 110 parts

[Comparative Example B2] Optical fiber was obtained in the same manner as in Example B1, except that the coating solution for the concavo-convex layer B1 of Example B1 was changed to the coating solution for the concavo-convex layer B4 of the following formulation, and the thickness of the concavo-convex layer was set to 7 μm. piece. <Concavo-convex layer coating liquid B4> ・Multifunctional acrylate oligomer 60 parts (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UV7640B functional group number 6～7) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.2 part of polyester modified polydimethylsiloxane (Made by BYK-CHEMIE, BYK370) ・Spherical polyacrylic acid-styrene copolymer particles 16 parts (average particle size 3.5 μm, refractive index 1.52) ・Silica fine particles (hydrophobic treatment: octylsilane treatment) 6 parts (manufactured by Airlogi, Japan, with an average particle size of 10-15 nm) ・Solvent 1 (toluene) 135 parts

[Comparative Example B3] An optical fiber was obtained in the same manner as in Example B1, except that the coating liquid B1 for the concavo-convex layer of Example B1 was changed to the coating liquid B5 for the concavo-convex layer of the following formulation, and the film thickness of the concavo-convex layer was set to 4 μm. piece. <Concavo-convex layer coating liquid B5> ・Aliphatic polyester skeleton 6-functional urethane acrylate 100 parts (manufactured by SARTOMER, CN968) ・3 parts of spherical polyacrylic acid-styrene copolymer particles (average particle size 2.5 μm, refractive index 1.52) ・Silica fine particles (hydrophobic treatment: methyl) 3 parts (manufactured by Airlogi, Japan, with an average particle size of 10-15 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.2 part of polyether-modified polysiloxane (manufactured by Shin-Etsu Silicones, KF6004) ・Solvent 1 (toluene) 150 parts ・Solvent 2 (MIBK) 35 parts

[Comparative Example B4] An optical sheet was obtained in the same manner as in Example B1, except that the concavo-convex layer coating solution B1 of Example B1 was changed to the concave-convex layer coating solution B6 of the following formulation, and the thickness of the concavo-convex layer was set to 3.8 μm . <Concavo-convex layer coating liquid B6> ・100 parts of neotaerythritol tetraacrylate (Kyoeisha Chemical Co., Ltd., Light acrylate PE-4A) ・Amorphous silica particles (hydrophobic treatment: silane coupling agent) 10 parts (manufactured by Fuji Silesia Chemical Co., Ltd., with an average aggregate particle size of 3.5 μm) ・Amorphous silica particles (hydrophobic treatment: silane coupling agent) 8 parts (manufactured by Fuji Silesia Chemical Co., Ltd., with an average aggregate particle size of 2 μm) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.3 part of polyether-modified polysiloxane (manufactured by Shin-Etsu Silicones, KF6004) ・Solvent (toluene) 150 parts

[Comparative Example B5] An optical sheet was obtained in the same manner as in Example B1, except that the uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B7 of the following formulation, and the film thickness of the uneven layer was set to 4 μm . <Concavo-convex layer coating liquid B7> ・100 parts of neotaerythritol tetraacrylate (Kyoeisha Chemical Co., Ltd., Light acrylate PE-4A) ・Amorphous silica particles (hydrophobic treatment: silane coupling agent) 2 parts (manufactured by Fuji Silesia Chemical Co., Ltd., with an average aggregate particle size of 3 μm) ・Photopolymerization initiator 3 parts (manufactured by BASF, Irgacure184) ・Polysiloxane-based leveling agent: 0.2 part of polyether-modified polysiloxane (manufactured by Shin-Etsu Silicones Co., Ltd., X-22-2516) ・Solvent (toluene) 150 parts

[table 3] table 3 Example B1 Example B2 Comparative Example B1 Comparative Example B2 Comparative Example B3 Comparative Example B4 Comparative Example B5 Vertical load (g) 100 500 1000 100 500 1000 100 500 1000 100 500 1000 100 500 1000 100 500 1000 100 500 1000 Static friction coefficient [μS] 0.190 0.893 1.466 0.220 0.750 1.540 0.118 0.450 0.992 0.148 0.636 1.605 0.111 0.416 1.140 0.301 0.981 2.300 0.190 0.512 1.460 Kinetic friction coefficient [μk] 0.099 0.576 1.199 0.137 0.546 1.380 0.095 0.401 0.812 0.120 0.537 1.188 0.095 0.378 0.722 0.193 0.722 1.884 0.140 0.398 0.984 Ratio (μs/μk) 1.92 1.55 1.22 1.61 1.37 1.12 1.24 1.12 1.22 1.23 1.18 1.35 1.17 1.10 1.58 1.56 1.36 1.22 1.36 1.29 1.48 Approximate a straight line y=-7.9× ^10-4 x+2.0 y=-5.5× ^10-4 x+1.7 - - - y=-3.9× ^10-4 x+1.6 - surface shape Ra _2.5 (μm) 0.47 0.29 0.18 0.16 0.08 0.74 0.42 Rz _2.5 (μm) 3.54 2.66 1.51 1.11 0.43 4.72 2.57 Rz _2.5 /Ra _2.5 7.5 9.1 8.5 7.2 5.6 6.3 6.1 S _2.5 (μm) 49.0 35.1 53.5 35.3 74.6 34.9 75.0 θa _2.5 (°) 3.6 1.9 1.4 1.4 0.3 6.6 1.2 Ry _2.5 (μm) 4.3 3.5 2.0 1.4 0.5 5.2 3.6 Sm _2.5 (μm) 123 109 141 108 163 91.5 177 Rz _0.8 (μm) 2.61 1.98 1.20 0.86 0.34 4.16 1.97 Rz _0.8 / (Rz _2.5 - Rz _0.8 ) 2.82 2.93 3.83 3.49 3.86 7.51 3.28 Ry _2.5 /Rz _2.5 1.21 1.32 1.32 1.26 1.16 1.10 1.40 θa _2.5 / (Ry _2.5 /Rz _2.5 ) 2.98 1.44 1.06 1.11 0.26 6.00 0.86 Outdoor anti-glare A A B B C A B Analytical B B A A A C B operability A B C C D B D

From the results in Table 3, it can be seen that the optical sheet of Example B1 can provide outdoor anti-glare properties and can improve the handleability. In addition, the resolution is also good.

B3. Fabrication of touch panel An ITO conductive film with a thickness of 20 nm was formed on the transparent substrate side of the optical sheets of Examples B1, B2 and Comparative Examples B1 to B5 by sputtering to form an upper electrode plate. Next, an ITO conductive film with a thickness of about 20 nm was formed on one surface of a tempered glass plate with a thickness of 1 mm by a sputtering method to prepare a lower electrode plate. Next, the ionized radiation curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as the coating liquid for spacers was dot-printed on the surface having the conductive film of the lower electrode plate by the screen printing method, and then used A high-pressure mercury lamp was irradiated with ultraviolet rays, and spacers with a diameter of 50 μm and a height of 8 μm were arranged at intervals of 1 mm. Next, the upper electrode plate and the lower electrode plate were arranged so that the conductive films faced each other, and the edges were adhered with a double-sided tape with a thickness of 30 μm and a width of 3 mm to prepare Examples B1, B2 and Comparative Examples. Resistive film touch panels of B1-B5. The resistive film touch panels of Examples B1 and B2 have outdoor anti-glare properties, and are good in operability and resolution.

B4. Production of display device (1) The optical sheets of Examples B1, B2 and Comparative Examples B1 to B5 were bonded to the surface glass plate of a commercially available ultra-high-definition liquid crystal display device (4.7 inches, pixel density of about 320 ppi) through a transparent adhesive to produce The display devices (1) of Examples B1, B2 and Comparative Examples B1 to B5. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the opposite side to the display element. The obtained display device (1) was visually evaluated for the presence or absence of glare. As a result of the display devices (1) of Examples B1 and B2, the glare was suppressed, the reflection of external light was less, and the visibility was good. In addition, the display device (1) of the embodiment B1 does not impair the resolution of the ultra-high-definition image.

B5. Production of display device (2) The substrates of the optical sheets of Examples B1, B2 and Comparative Examples B1 to B5 were changed to a polyethylene terephthalate film with a thickness of 50 μm (retardation value of 2,500 nm), and the same as that of Examples B1 and B2. In the same manner as Comparative Examples B1 to B5, optical sheets of Examples B3 and B4 and Comparative Examples B6 to B10 were produced. The respective physical property values in Table 3 of the optical sheets of Examples B3, B4 and Comparative Examples B6 to B10 are substantially the same as those of Examples B1, B2 and Comparative Examples B1 to B5. The optical sheets of Examples B3, B4 and Comparative Examples B6 to B10, and the organic EL display element of the three-color independent mode with the microcavity structure, have a commercially available organic EL display device with a polarizing element (based on the CIE-xy chromaticity diagram). The surface glass plates of the BT.2020 coverage: 77%) were bonded through a transparent adhesive, and the display devices (2) of Examples B3, B4 and Comparative Examples B6 to B10 were produced. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the opposite side to the display element.

[Evaluation of Display Device (2)] ＜Color unevenness in gradation＞ The screen of the display device (2) is displayed in white or substantially white. The screen was visually observed from various angles through polarized sunglasses to evaluate whether the color unevenness of the gradation was recognizable. 20 people evaluated according to the following evaluation criteria: 2 points were given for those whose gradation was unrecognizable, and 1 point for those whose gradation was seldom recognizable but did not interfere with the image quality. If the color unevenness of the gradation color is clearly recognized and seriously hinders the image quality, it is set to 0 points. The average score of 20 people is 1.7 points or more as A, 1.4 points or more but less than 1.7 points as B, 1.0 points or more and less than 1.4 points as C, and less than 1.0 points as C for D. The results are shown in Table 4.

The display elements constituting the display device (2) have a very wide color gamut and are prone to produce uneven color gradients. However, since the display device (2) of Example B3 has a concave-convex shape with a large Ra and moderate randomness, the color unevenness of the gradation is almost completely unrecognizable.

[Table 4] Table 4 Example B3 Example B4 Comparative Example B6 Comparative Example B7 Comparative Example B8 Comparative Example B9 Comparative Example B10 uneven color A B C C D B D

1: Resistive film touch panel 11: Transparent substrate 12: Transparent conductive film 13: Spacer 2: Electrostatic capacitive touch panel 21: Transparent substrate 22: Transparent conductive film (X-axis electrode) 23: Transparent conductive film (Y-axis electrode) 24: Adhesive layer

FIG. 1 is a cross-sectional view showing an embodiment of the resistive film type touch panel of the present invention. FIG. 2 is a cross-sectional view showing an embodiment of the electrostatic capacitance type touch panel of the present invention. FIG. 3 is a diagram illustrating a method of calculating the average inclination angle θa. 4 is a graph showing the unevenness of the optical sheet of the present invention, when the ratio (μs/μk) of the coefficient of static friction μs to the coefficient of kinetic friction μk (μs/μk) is taken as the vertical axis, and the vertical load Tg is taken as the horizontal axis, since the A graph of an example of an approximate first-order straight line obtained by the least-squares method for a curve in the range of vertical load of 100 to 1000 g.

1: Resistive film touch panel

11: Transparent substrate

12: Transparent conductive film

13: Spacer

Claims (9)

A touch panel, the surface on the operator side has concavities and convexities, so that a sapphire needle with a front end radius of 0.3mm is in contact with the concavity and convexity vertically, a vertical load of 100g is applied to the squeegee, and at the same time, the squeegee is 10mm/ The speed of the second is to carry out a round trip with a one-way length of 10mm, and the static friction coefficient acting on the scraper needle at this time is set to μs ₁₀ ; the scraper needle made of sapphire with a front end radius of 0.3mm is made to contact the unevenness vertically, and the scraper needle is made of sapphire. A vertical load of 100 g is applied to the needle, and at the same time, the scraping needle is made to perform a round trip with a single-pass length of 10 mm at a speed of 20 mm/sec. When the static friction coefficient acting on the scraping needle is set to μs ₂₀ , μs ₁₀ and μs ₂₀ The following condition (A1) is satisfied, and the arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cutoff value is 2.5 mm satisfies the following condition (A2), and the unevenness is cut off. The ten-point average roughness (Rz _2.5 ) of JIS B0601:1994 when the value is set to 2.5 mm and the ten-point average roughness (Rz _0.8 ) of JIS B0601:1994 when the cutoff value is set to 0.8 mm satisfy the following conditions (A5), 0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1), 0.10μm≦Ra _2.5 ≦0.60μm (A2), 0.10μm≦Rz _2.5 -Rz _0.8 ≦1.20μm (A5). The touch panel of claim 1, wherein the Rz _2.5 and the Ra _2.5 satisfy the following condition (A3), 5.7≦Rz _2.5 /Ra _2.5 (A3). The touch panel of claim 1 or 2, wherein, regarding the unevenness, the maximum height (Ry _2.5 ) of JIS B0601:1994 when the cut-off value is 2.5 mm and the Rz _2.5 satisfy the following conditions (A6), Ry _2.5 /Rz _2.5 ≦1.5 (A6). The touch panel according to claim 3, wherein, regarding the unevenness, the average inclination angle (θa _2.5 ) of the unevenness when the cutoff value is 2.5 mm and the Ry _2.5 /Rz _2.5 satisfy the following condition (A7), 0.8≦ θa _2.5 /(Ry _2.5 /Rz _2.5 )≦5.0 (A7). The touch panel of claim 1 or 2, wherein the unevenness is provided on one surface of the optical sheet. The touch panel of claim 5, wherein the optical sheet has a transparent substrate with a retardation value exceeding 0 nm and less than 3,000 nm. A display device, the outermost surface of the output surface side of the display element has concavities and convexities, and a sapphire needle with a front end radius of 0.3mm is made to vertically contact the concavities and convexities, and a vertical load of 100g is applied to the scraper, and at the same time, the The scraping needle performs a round trip with a one-way length of 10 mm at a speed of 10 mm/s, and the static friction coefficient acting on the scraping needle at this time is set as μs ₁₀ ; For the unevenness, a vertical load of 100g is applied to the scraper needle, and at the same time, the scraper needle is made to reciprocate once with a one-way length of 10mm at a speed of 20mm/sec. The static friction coefficient acting on the scraper needle at this time is set to μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following condition (A1), and regarding the unevenness, the arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cutoff value is 2.5 mm satisfies the following condition (A2), and, Regarding the unevenness, the ten-point average roughness (Rz 2.5 ) of JIS B0601:1994 when the cut-off value is 2.5 mm, and the ten-point average roughness (Rz _2.5 ) of JIS B0601: 1994 when the cut-off value is 0.8 mm _0.8 ) Satisfy the following conditions (A5), 0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1), 0.10μm≦Ra _2.5 ≦0.60μm (A2), 0.10μm≦Rz _2.5 -Rz _0.8 ≦1.20μm (A5). An optical sheet with unevenness on one side, a sapphire needle with a front end radius of 0.3mm is made to contact the unevenness vertically, a vertical load of 100g is applied to the scraper, and at the same time, the scraper is made to perform a single pass at a speed of 10mm/sec. One round trip with a length of 10mm, the static friction coefficient acting on the scraper needle at this time is set to μs ₁₀ ; the scraper needle made of sapphire with a front end radius of 0.3mm is made to contact the unevenness vertically, and a vertical load of 100g is applied to the scraper needle , and at the same time make the scraping needle go back and forth with a single-pass length of 10 mm at a speed of 20 mm/sec. When the static friction coefficient acting on the scraping needle is set to μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following conditions ( A1) Regarding the unevenness, the arithmetic mean roughness (Ra _2.5 ) of JIS B0601:1994 when the cutoff value is 2.5 mm satisfies the following condition (A2), and regarding the unevenness, the cutoff value is 2.5 mm The ten-point average roughness (Rz _2.5 ) of JIS B0601:1994 and the ten-point average roughness (Rz _0.8 ) of JIS B0601:1994 when the cutoff value is 0.8 mm satisfy the following conditions (A5), 0.70 ≦μs ₂₀ /μs ₁₀ ≦1.75 (A1), 0.10μm≦Ra _2.5 ≦0.60μm (A2), 0.10μm≦Rz _2.5 -Rz _0.8 ≦1.20μm (A5). A screening method for an optical sheet, which is based on a screening method for an optical sheet with concavities and convexities on one side, the screening method selects the optical sheet as the optical sheet located on the uppermost part of the touch panel, and uses a sapphire scraper with a radius of 0.3mm at the front end. Vertically contact the concave and convex, apply a vertical load of 100g to the scraper, and at the same time make the scraper make a round trip with a one-way length of 10mm at a speed of 10mm/sec, and set the static friction coefficient acting on the scraper at this time. is μs ₁₀ ; a sapphire needle with a front end radius of 0.3mm is made to contact the unevenness vertically, a vertical load of 100g is applied to the scraper needle, and at the same time, the scraper needle is made to perform a round trip with a single-pass length of 10mm at a speed of 20mm/sec Once, when the static friction coefficient acting on the squeegee at this time is μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following condition (A1), and the cut-off value is set to 2.5mm. JIS B0601:1994 The arithmetic mean roughness (Ra _2.5 ) satisfies the following condition (A2), and for the unevenness, the ten-point mean roughness (Rz _2.5 ) of JIS B0601:1994 when the cut-off value is 2.5 mm, and the cut-off value When the value is set to 0.8mm, the ten-point average roughness (Rz _0.8 ) of JIS B0601:1994 satisfies the following conditions (A5), 0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1), 0.10μm≦Ra _2.5 ≦0.60μm (A2), 0.10μm≦Rz _2.5 -Rz _0.8 ≦1.20μm (A5).

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