TWI682157B - Quantitative assessment method of glare - Google Patents

Abstract

Provide a way to visually evaluate The degree of glare of the anti-glare film can also be a method of quantitative glare evaluation that has a high correlation with glare when the anti-glare film is viewed obliquely.

With one aspect of the invention, a glare fix is provided The quantity evaluation method is provided with: a light-transmitting base material (31), an anti-glare layer (32) provided on the light-transmitting base material (31) and having an uneven surface (32A), and the surface (30A) is formed It is a method for quantitative evaluation of glare of the anti-glare film (30) of the uneven surface, which is a grid-like shape of the surface (30A) of the anti-glare film (30) away from the back (30B) side of the anti-glare film (30) The matrix filter (20) is separated by 3.76 mm or more, so that the light from the white light source (10) passes through the matrix filter (20) and enters from the back (30B) side of the anti-glare film (30) The anti-glare film (30) photographs the transmitted light emitted from the surface (30A) of the anti-glare film (30) and takes the transmitted light as an image. Based on the taken image, the uneven brightness distribution is obtained Standard deviation, and the value of the obtained standard deviation is regarded as a glare value.

Description

Quantitative assessment method of glare

The invention relates to a quantitative evaluation method of glare.

Image display surfaces in image display devices such as liquid crystal displays (LCDs), cathode ray tube display devices (CRTs), plasma displays (PDPs), electroluminescent displays (ELDs), field emission displays (FEDs), etc. An anti-glare film having irregularities on the surface or an anti-reflection film having an anti-reflection layer on the outermost surface is provided to suppress the reflection of the background of the observer and the observer.

The anti-glare film scatters external light on the uneven surface of the anti-glare layer to suppress the reflection of the observer and the background of the observer. The anti-glare film mainly includes: a light-transmitting base material, and an anti-glare layer provided on the light-transmitting base material with an uneven surface.

In the image display device, due to the influence of the uneven surface of the black matrix and the anti-glare film, glare may be generated. Therefore, various methods for evaluating the glare of anti-glare films have been proposed (refer to Patent Documents 1 to 4).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-304648

[Patent Document 2] Japanese Patent Laid-Open No. 2003-279485

[Patent Document 3] Japanese Patent Application Publication No. 2007-71723

[Patent Document 4] Japanese Patent Laid-Open No. 2009-236621

Compared to when viewing the screen from the front, glare is more likely to be seen when viewing the screen diagonally with an angle of more than 30° from the normal direction of the screen, even when viewing the screen from the front When glare is not confirmed at the time, glare may also be confirmed when the screen is viewed obliquely.

In particular, in an ultra-high-definition image display device called 4K2K (horizontal pixel number 3840 x vertical pixel number 2160) with a horizontal pixel number of 3000 or more, glare is likely to occur when the screen is viewed obliquely.

Regarding the problem of glare when viewing a screen from an oblique direction as shown above, in the glare evaluation methods of Patent Documents 1 to 4, there is no correlation with the glare when viewing from an oblique direction, and it cannot be properly evaluated.

On the other hand, even if the glare of the anti-glare film is to be evaluated obliquely, the evaluation object is evaluated obliquely using a CCD camera, the focus of the CCD camera cannot be focused on the entire evaluation object, so it cannot be properly evaluated. In addition, in fact, whether the If glare occurs in the glare film, there is a risk of unevenness caused by individual differences. Therefore, an objective quantitative evaluation method is sought.

The present invention has been completed to solve the above-mentioned problems. That is, the objective is to provide a quantitative glare assessment that has a high correlation with the glare when the anti-glare film is viewed obliquely even if the degree of glare in the anti-glare film is not visually evaluated from the oblique direction method.

According to one aspect of the present invention, there is provided a method for quantitatively evaluating glare, comprising: a light-transmitting base material, and an anti-glare layer provided on the light-transmitting base material and having an uneven surface, and the surface is formed as an uneven surface The method for quantitative evaluation of glare of an anti-glare film is to separate the surface of the anti-glare film from the grid-like matrix filter arranged on the back side of the anti-glare film by 3.76 mm or more in a state separated from white The light of the light source passes through the matrix filter, enters the anti-glare film from the back side of the anti-glare film, photographs the transmitted light emitted from the surface of the anti-glare film, and takes the transmitted light as a portrait, The standard deviation of the uneven brightness distribution is obtained from the acquired image, and the value of the obtained standard deviation is taken as the glare value.

With the method for quantitatively evaluating glare according to one aspect of the present invention, since the surface of the anti-glare film is separated from the matrix filter by 3.76 mm or more, the glare is evaluated. To estimate the degree of glare in the anti-glare film, the numerical value can also be used to confirm how much glare occurs when the anti-glare film is viewed obliquely.

10‧‧‧White light source

20‧‧‧Matrix filter

30、70‧‧‧Anti-glare film

30A, 70A‧‧‧surface

30B, 70B‧‧‧Back

31‧‧‧Light transmissive substrate

32‧‧‧Anti-glare layer

32A, 71A‧‧‧Concave and convex

40‧‧‧Camera device

50‧‧‧Support board

50A‧‧‧The surface of the white light source 10 side of the support board 50

60‧‧‧ spacer

71‧‧‧Functional layer

80‧‧‧Picture processing device

d‧‧‧Distance

FIG. 1 is a diagram for explaining a method for quantitatively evaluating glare in the embodiment.

FIG. 2 is a schematic configuration diagram of the anti-glare film shown in FIG. 1.

Fig. 3 is a schematic configuration diagram of another anti-glare film.

Hereinafter, referring to the drawings, a method for quantitatively evaluating glare of the anti-glare film of the embodiment will be described. 1 is a diagram for explaining a method for quantitatively evaluating glare of the anti-glare film of the present embodiment, FIG. 2 is a schematic configuration diagram of the anti-glare film shown in FIG. 1, and FIG. 3 is a schematic configuration diagram of other anti-glare films. However, in this specification, the terms "film", "sheet", and "board" are not intended to distinguish one from the other based only on the different names. Therefore, for example, the "film" system also includes the concept of members that can also be referred to as sheets or plates. As a specific example, the "anti-glare film" also includes members called "anti-glare sheet" or "anti-glare plate".

<Quantitative assessment method of glare>

First, as shown in FIG. 1, the white light source 10, the lattice-shaped matrix filter 20, the anti-glare film 30, and the imaging device 40 are arranged in this order. By using the combination of the white light source 10 and the matrix filter 20, the liquid crystal can be reproduced in a pseudo-like manner monitor.

The white light source 10 is preferably a white surface light source for a liquid crystal display that more faithfully reproduces the pseudo-similarity. For a white light source, the series includes, for example, LIGHTBOX made by HAKUBA. The white light source 10 is arranged so that the matrix filter 20 is slightly separated.

The lattice matrix filter 20 shown in FIG. 1 is composed of a black matrix. Specifically, for example, the matrix filter 20 is composed only of a black matrix formed to have a length of 85 nm, a width of 65 nm, a thickness of 1 nm, and a pitch of 127 μm×127 μm (200 ppi), and functions as an uncolored pseudo-color filter. Features. Among them, a pseudo-like color filter is used as a matrix filter, but a colored color filter can also be used as a matrix filter.

The matrix filter 20 is formed on one side of a light-transmitting support plate 50 such as a glass plate. Specifically, the matrix filter 20 is formed on the surface 50A of the support plate 50 on the white light source 10 side.

As shown in FIGS. 1 and 2, the anti-glare film 30 to be evaluated includes a light-transmitting base 31 and an anti-glare layer 32 provided on the light-transmitting base 31 and having an uneven surface 32A.

The surface 30A of the anti-glare film 30 is formed as an uneven surface reflecting the uneven surface 32A of the anti-glare layer 32. Since the anti-glare film 30 shown in FIG. 2 is not provided with a functional layer such as a low refractive index layer on the anti-glare layer 32, the uneven surface 32A of the anti-glare layer 32 is formed as the surface 30A of the anti-glare film 30. The anti-glare film 70 shown in FIG. 3 may be provided with a functional layer 71 on the anti-glare layer 32. At this time, the surface 71A of the functional layer 71 is formed as an anti-glare film 70 的面70A。 The surface 70A. "Functional layer" refers to a layer intended to exert certain functions in an anti-glare film, and specifically, for example, a layer for exerting functions such as anti-reflection property, anti-static property, or anti-fouling property. The functional layer system is not only a single layer, but may also be a laminate of two or more layers. If a low-refractive-index layer having a refractive index lower than that of the anti-glare layer 32 is used as the functional layer 71, the low-refractive-index layer has a thin film thickness. Therefore, on the surface of the low-refractive-index layer, the uneven surface of the anti-glare layer The uneven shape is maintained almost as it is. Therefore, the uneven shape in the surface 70A of the anti-glare film 70 is substantially formed into the uneven shape in the uneven surface 32A of the anti-glare layer 32.

The front surface 30A of the anti-glare film 30 is separated from the matrix filter 20 disposed on the back surface 30B side of the anti-glare film 30 by 3.76 mm or more. That is, the distance d shown in FIG. 1 is 3.76 mm or more. Here, in this specification, "the surface of the anti-glare film is separated from the matrix filter by 3.76 mm or more" means that the surface of the anti-glare film is separated from the back surface of the anti-glare film in the normal direction of the back surface by The distance from the position where the thickness of the anti-glare film is separated to the surface of the matrix filter on the anti-glare film side is 3.76 mm or more. Whether the distance is 3.76 mm or more, it can be confirmed by directly measuring the distance from the surface of the anti-glare film to the surface of the matrix filter on the anti-glare film side, but it is also possible to determine the distance between the surface of the anti-glare film and the matrix The thickness of the anti-glare film and the member between the surfaces of the filter on the anti-glare film side were totaled and confirmed. In addition, the "back surface" of the anti-glare film in this specification means the surface opposite to the surface of the anti-glare film. In this embodiment, the back surface 30B of the anti-glare film 30 is formed on the opposite side to the surface of the light-transmitting base 31 on the anti-glare layer 32 side. Among them, if you use anti-glare For the film 70, the matrix filter 20 is arranged on the back surface 70B side of the anti-glare film 70. In addition, the surface of the anti-glare film is formed as a concave-convex surface, so the thickness of the anti-glare film varies depending on the location, but the above-mentioned "thickness of the anti-glare film" is set to measure the thickness of the anti-glare film at 10 points, which means that The average.

The lower limit of the distance between the matrix filter 20 and the surface 30A of the anti-glare film 30 is preferably 3.0 mm or more. The upper limit of the distance between the matrix filter 20 and the surface 30A of the anti-glare film 30 is preferably 10 mm or less, and more preferably 8 mm or less. If the distance between the matrix filter and the anti-glare film exceeds 10 mm, since glare is unlikely to occur, there is a possibility that the glare cannot be properly evaluated.

The distance between the matrix filter 20 and the surface 30A of the anti-glare film 30 may be interposed between the matrix filter 20 and the surface 30A of the anti-glare film 30 to form a light-transmitting interval of 3.76 mm or more Pieces 60. The spacer 60 includes glass plates and the like. In this embodiment, the support plate 50 and the spacer 60 are in contact.

If the matrix filter 20 is formed on the support plate 50 and the spacer 60 is interposed between the matrix filter 20 and the anti-glare film 30, if the total thickness of the support plate 50 and the spacer 60 is formed to be 3.76 mm or more, The distance between the matrix filter 20 and the anti-glare film 30 is surely formed to be 3.76 mm or more.

In this embodiment, the support plate 50 and the spacer 60 are interposed between the matrix filter 20 and the anti-glare film 30, but if the thickness of the support 50 is formed to be 3.76 mm or more, the matrix can be reliably filtered The distance between the light sheet 20 and the surface 30A of the anti-glare film 30 is 3.76 mm As described above, the spacer 60 may not be interposed. In addition, if the distance between the matrix filter 20 and the surface 30A of the anti-glare film 30 is 3.76 mm or more, an air layer may be interposed between the matrix filter 20 and the anti-glare film 30, but if it is interposed in the air layer, there may be The reflection of the interface may adversely affect the measurement. Therefore, it is preferable that the matrix filter 20 and the anti-glare film 30 be filled with a transparent medium other than gas. The anti-glare film 30 adheres the spacer 60 with a transparent adhesive (not shown).

The anti-glare film 30 includes a light-transmitting base 31 and an anti-glare layer 32, but the light-transmitting base 31 is not particularly limited if it has light permeability, and examples include cellulose acylate Substrate, cycloolefin polymer substrate, polycarbonate substrate, acrylic polymer substrate, polyester substrate, or glass substrate.

The thickness of the light-transmitting substrate 31 is not particularly limited, and may be 5 μm or more and 1000 μm or less. From the viewpoint of handleability, the lower limit of the thickness of the light-transmitting substrate 31 is preferably 15 μm or more, and preferably 25 μm or more. Better. From the viewpoint of thinning, the upper limit of the thickness of the light-transmitting substrate 31 is preferably 80 μm or less.

The anti-glare layer 32 is a layer that exerts anti-glare properties. The anti-glare layer 32 may also be an anti-glare layer and can perform other functions. Specifically, the anti-glare layer 32 may be a layer that exhibits anti-glare properties and functions such as hard coating properties, anti-reflection properties, antistatic properties, or anti-fouling properties.

The thickness of the anti-glare layer 32 is not particularly limited, and may be formed to 1 μm or more and 20 μm or less. The thickness of the anti-glare layer 32 is measured by a profile electron microscope (TEM, STEM) image using image processing software Value. Here, the surface of the anti-glare layer is formed as a concave-convex surface, so the thickness varies depending on the location, but the above-mentioned "thickness of the anti-glare layer" is the thickness of the anti-glare layer measured at 10 points, which means the average value .

The method for forming the uneven surface 32A of the anti-glare layer 32 includes, for example, (A) a method of forming an uneven surface using a composition for an anti-glare layer including a curable resin precursor and fine particles that become a binder resin after curing. ; (B) a method of forming an uneven surface by a transfer method using a mold; (C) a method of forming an uneven surface by sandblasting the surface of the anti-glare layer; or (D) by an embossing roller A method of forming irregularities on the surface of the antiglare layer by forming irregularities. Among these, the method of (A) above is preferable because of ease of manufacturing. If the anti-glare layer is formed by the method (A) above, the anti-glare layer includes a binder resin and fine particles.

The imaging system of the transmitted light emitted from the surface 30A of the anti-glare film 30 uses the imaging device 40, but for example, a CCD camera (Charge-Coupled Device camera) can be used as the imaging device 40.

The distance between the anti-glare film 30 and the imaging device 40 varies depending on the resolution of the imaging device 40, but is preferably, for example, 200 mm or more and 300 mm or less. When shooting, the focal point of the imaging device 40 is matched with the anti-glare film 30, and the aperture is fitted where appropriate.

The image processing device 80 is electrically connected to an image processing device 80 that performs image processing and the like to obtain a standard deviation of uneven brightness distribution in transmitted light.

After the anti-glare film 30 and the like are arranged as described above, the white light source 10 transmits the light through the matrix filter 20 and the back of the anti-glare film 30 The surface 30B is incident, and the imaging device 40 photographs the transmitted light emitted from the surface 30A of the anti-glare film 30.

Next, the transmitted light obtained by photography is taken as an image in the image processing device 80. When the captured image system digitizes the glare, image processing is performed to obtain an appropriate value. The image processing is composed of, for example, low-pass filtering, shading correction, and contrast emphasis. The image processing system can be performed using image processing software such as ImagePro Plus ver.6.2 (manufactured by Media Cybernetics). The following describes the case of using ImagePro Plus ver.6.2 as the image processing software.

In the image processing, first, an area for performing image processing on the acquired image is selected. This is based on the reason that only the portion where the anti-glare film is present is subject to image processing. Specifically, for example, a region of 200×160 pixels is selected.

Next, in this area, in order to prevent the cancellation of significant digits in the calculation of the image processing, the 8-bit grayscale image is converted into 16-bit grayscale. Next, the image is filtered to remove components from the black matrix pattern. This filtering is performed by applying a low-pass filter to the extent that the matrix filter becomes indistinguishable. Specifically, for example, the low-pass filter is selected by the emphasis label of the filter command, and filtering is performed under the conditions of 3×3, frequency 3, and intensity 10.

After filtering, the shadow correction is performed, and then the contrast is emphasized. The emphasis of contrast is a process for easily viewing the brightness distribution in assessing glare. Specifically, for example, the contrast is set to 96 and the brightness is set to 48.

Convert the image obtained above into 8-bit gray scale Among them, 150×110 pixels, the unevenness of the value of each pixel is calculated as the standard deviation value, thereby digitizing the glare. The obtained glare value is compared with a predetermined value, whereby the glare property of the anti-glare film can be evaluated. The smaller the numerical glare value, the less glare. Therefore, the glare value is preferably 14 or less, and more preferably 12 or less. The "oblique direction" in this specification means that the direction normal to the light-transmissive base material in the anti-glare film is inclined by 30° or more from left to right.

In this embodiment, the surface 30A of the anti-glare film 30 is separated from the matrix filter 20 by 3.76 mm or more, and the glare of the anti-glare film 30 is evaluated. Here, although the reason is not clear, the inventors found that when the surface 30A of the anti-glare film 30 is separated from the matrix filter by 3.76 mm or more, when evaluating the glare of the anti-glare film, in fact, actually This is relevant to the evaluation of glare of the anti-glare film when viewed obliquely. Therefore, according to the present embodiment, even if the glare generated in the anti-glare film is not visually evaluated from an oblique direction, when the anti-glare film is viewed obliquely, the degree of the glare can be confirmed by numerical values.

The anti-glare film obtained by the evaluation method of the present embodiment with a glare value of 12 or less is incorporated into an image display device, but it is particularly referred to as 4K2K (horizontal pixels 3840×vertical pixels) It is preferable to use an ultra-high-definition image display device with a number of horizontal pixels of at least 2160) of 3000 or more.

[Examples]

In order to explain the present invention in detail, the following examples are carried out Explain, but the invention is not limited to these records.

<Preparation of composition for anti-glare layer>

First, each component is blended so as to have the composition shown below to obtain a composition for an anti-glare layer.

(Composition 1 for anti-glare layer)

‧Silica dioxide particles (Fumed silica with octyl silane treatment, average primary particle diameter of 12 nm, manufactured by Japan Aerosil): 0.5 parts by mass

‧Silica dioxide microparticles (Sily-treated gas-phase silica, average primary particle diameter 12nm, manufactured by Japan Aerosil): 0.2 parts by mass

‧Pentaerythritol tetraacrylate (PETTA) (product name "PETA", manufactured by Daicel-Cytec): 50 parts by mass

‧Urethane acrylate (product name "V-4000BA", manufactured by DIC): 50 parts by mass

‧Polymerization initiator (IRGACURE 184, manufactured by BASF Japan): 5 parts by mass

‧Polyether modified silicone (product name "TSF4460", manufactured by Momentive Performance Materials): 0.025 parts by mass

‧Toluene: 70 parts by mass

‧Isopropyl alcohol: 40 parts by mass

‧Cyclohexanone: 40 parts by mass

(Composition 2 for anti-glare layer)

‧Organic fine particles (spherical polyacrylate-styrene copolymer particles, particle size 3.5 μm, refractive index 1.545, manufactured by Sekisui Chemical Co., Ltd.): 12 parts by mass

‧Pentaerythritol triacrylate (product name "KAYARAD-PET-30", manufactured by Nippon Kayaku): 38 parts by mass

‧Isocyanuric acid EO modified triacrylate (product name "M-313", manufactured by East Asia Synthetic Corporation): 22 parts by mass

‧Inorganic ultrafine particles (silica with reactive functional groups introduced on the surface, average primary particle diameter 12nm, solvent MIBK, solid content 30%, manufactured by Nissan Chemical Co., Ltd.): 120 parts by mass

‧Polymerization initiator (IRGACURE 184, manufactured by BASF Japan): 5 parts by mass

‧Polyether modified silicone (product name "TSF4460", manufactured by Momentive Performance Materials): 0.025 parts by mass

‧Toluene: 135 parts by mass

(Composition 3 for anti-glare layer)

‧Organic fine particles (spherical polyacrylate-styrene copolymer particles, particle size 5 μm, refractive index 1.525, manufactured by Sekisui Chemical Co., Ltd.): 20 parts by mass

‧Pentaerythritol triacrylate (product name "KAYARAD-PET-30", manufactured by Nippon Kayaku): 38 parts by mass

‧Isocyanuric acid EO modified triacrylate (product name "M- 313", manufactured by East Asia Synthetic Corporation): 22 parts by mass

‧Inorganic ultrafine particles (silica with reactive functional groups introduced on the surface, average primary particle diameter 12nm, solvent MIBK, solid content 30%, manufactured by Nissan Chemical Co., Ltd.): 120 parts by mass

‧Polymerization initiator (IRGACURE 184, manufactured by BASF Japan): 5 parts by mass

‧Polyether modified silicone (product name "TSF4460", manufactured by Momentive Performance Materials): 0.025 parts by mass

‧Toluene: 135 parts by mass

(Composition 4 for anti-glare layer)

‧Organic microparticles (hydrophilized acrylate-styrene copolymer particles, average particle diameter 2.0 μm, refractive index 1.55, manufactured by Sekisui Chemical Co., Ltd.): 3 parts by mass

‧ Fumed silica (silane treatment, average particle diameter 12nm, manufactured by Japan Aerosil): 1 part by mass

‧Pentaerythritol tetraacrylate (PETTA) (product name: PETA, manufactured by Daicel-Cytec): 60 parts by mass

‧Carbamate acrylate (product name: UV1700B, manufactured by Japan Synthetic Chemical Co., Ltd., weight average molecular weight 2000, number of functional groups 10): 40 parts by mass

‧Polymerization initiator (IRGACURE 184, manufactured by BASF Japan): 5 parts by mass

‧Polyether modified silicone (TSF4460, Momentive Performance Materials): 0.025 parts by mass

‧Toluene: 105 parts by mass

‧Isopropyl alcohol: 30 parts by mass

‧Cyclohexanone: 15 parts by mass

(Composition 5 for anti-glare layer)

‧Organic microparticles (spherical polystyrene particles, particle size 3.5 μm, refractive index 1.59, manufactured by Zongken Chemical Company): 12 parts by mass

‧Pentaerythritol triacrylate (product name "KAYARAD-PET-30", manufactured by Nippon Kayaku): 90 parts by mass

‧Acrylic polymer (molecular weight 75,000, manufactured by Mitsubishi Rayon): 10 parts by mass

‧Polymerization initiator (IRGACURE 184, manufactured by BASF Japan): 3 parts by mass

‧Polyether modified silicone (TSF4460, manufactured by Momentive Performance Materials): 0.025 parts by mass

‧Toluene: 145 parts by mass

‧Cyclohexanone: 60 parts by mass

(Composition 6 for anti-glare layer)

‧Inorganic fine particles (gel-formed amorphous silica, hydrophobic treatment, average particle diameter (laser diffraction scattering method) 4.1 μm, manufactured by Fuji Sylysia): 14 parts by mass

‧Pentaerythritol triacrylate (product name "KAYARAD-PET- 30", manufactured by Nippon Kayaku Co., Ltd.): 100 parts by mass

‧Polymerization initiator (IRGACURE 184, manufactured by BASF Japan): 5 parts by mass

‧Polyether modified silicone (TSF4460, manufactured by Momentive Performance Materials): 0.2 parts by mass

‧Toluene: 150 parts by mass

‧MIBK: 35 parts by mass

<Preparation of composition for low refractive index layer>

The components are blended so as to have the composition shown below to obtain a composition for a low refractive index layer.

(Composition for low refractive index layer)

‧Hollow silica particles (solid content of hollow silica particles: 20% by mass, solution: methyl isobutyl ketone, average particle diameter: 50 nm): 40 parts by mass

‧Pentaerythritol triacrylate (PETA) (product name: PETIA, manufactured by Daicel-Cytec): 10 parts by mass

‧Polymerization initiator (IRGACURE 127; manufactured by BASF Japan): 0.35 parts by mass

‧Modified silicone oil (X22164E; manufactured by Shin-Etsu Chemical Co., Ltd.): 0.5 parts by mass

‧Methyl isobutyl ketone (MIBK): 320 parts by mass

‧Propylene glycol methyl ether acetate (PGMEA): 161 parts by mass

<Sample 1>

Prepare a cellulose acetate triacetate resin film (manufactured by Fujifilm, TD60UL) with a thickness of 60 μm as a light-transmitting base material, and apply the composition 1 for the antiglare layer on one side of the cellulose triacetate resin film, and Form a coating film. Next, the formed coating film was circulated with dry air at 50°C for 15 seconds at a flow rate of 0.2 m/s, and then circulated with dry air at 70°C for 30 seconds at a flow rate of 10 m/s. Drying, thereby evaporating the solvent in the coating film, and irradiating ultraviolet rays in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light amount becomes 100 mJ/cm ² to harden the coating film, thereby forming a thickness of 4.0 μm (At the time of hardening) the anti-glare layer, and the anti-glare film of sample 1 was produced.

<Sample 2>

In sample 2, the anti-glare layer composition 2 was used instead of the anti-glare layer composition 1 and the thickness of the anti-glare layer at the time of curing was set to 5.0 μm. film.

<Sample 3>

In Sample 3, an anti-glare layer was produced in the same manner as Sample 1, except that the composition 3 for the anti-glare layer was used instead of the composition 1 for the anti-glare layer, and the thickness of the anti-glare layer when cured was 7.0 μm. film.

<Sample 4>

In Sample 4, an anti-glare film was produced in the same manner as in Sample 1, except that the composition 4 for anti-glare layer was used instead of the composition 1 for anti-glare layer.

<Sample 5>

In Sample 5, the anti-glare layer composition 5 was used instead of the anti-glare layer composition 1, and the thickness of the anti-glare layer at the time of curing was set to 4.5 μm. film.

<Sample 6>

In sample 6, the anti-glare layer composition 6 was used instead of the anti-glare layer composition 1 and the thickness of the anti-glare layer at the time of curing was set to 2.0 μm. film.

<Sample 7>

In Sample 7, the antiglare layer was formed on the cellulose triacetate resin film in the same manner as in Sample 1, except that the integrated light amount of ultraviolet light was 50 mJ/cm ² . Next, on the surface of the anti-glare layer, the composition for the low refractive index layer was applied so that the film thickness after drying (40° C.×1 minute) became 0.1 μm, under a nitrogen atmosphere (oxygen concentration 200 ppm or less) , An ultraviolet light was irradiated with an integrated light amount of 100 mJ/cm ² to harden it to form a low refractive index layer, and an anti-glare film of sample 7 was produced.

<Example>

In each of the anti-glare films of samples 1 to 7, on the back side of the anti-glare film (the surface opposite to the surface on which the anti-glare layer of the triacetate cellulose film is formed), a thickness of 3 mm was bonded with a transparent adhesive glass plate. In addition, the glass surface on which the anti-glare film was not bonded to the glass plate and the glass surface on which the black matrix was formed with 200 ppi on one side and the thickness of the 0.7 mm glass plate were not bonded with water . That is, in samples 1 to 7, the surface of the anti-glare film was separated from the black matrix by 3.76 mm. To the laminate thus obtained, light from a white surface light source (LIGHTBOX manufactured by HAKUBA, average brightness 1000 cd/m ² ) was irradiated from the black matrix side, and the glare was caused by the pseudo-similarity. It was photographed from the anti-glare film side using a CCD camera (KP-M1, C mounting adapter, close-up mount; PK-11A Nikon, camera lens; 50mm, F1.4s NIKKOR). The distance between the CCD camera and the anti-glare film is set to 250 mm, and the focus of the CCD camera is adjusted in accordance with the anti-glare film. Import the image captured by the CCD camera to a personal computer, and analyze it using image processing software (ImagePro Plus ver.6.2; manufactured by Media Cybernetics) as shown below. First, the 200×160 pixel area is selected from the taken portrait, and the area is converted into 16-bit gray scale. Next, the low-pass filter is selected by the emphasis label of the filter command, and the filter is applied under the conditions of 3×3, frequency 3, and intensity 10. This removes the components from the black matrix pattern. Next, select Flattening and perform shading correction on the conditions of background: dark and wide object width 10. Next, the contrast emphasis command is formed as contrast: 96, brightness: 48 for contrast emphasis. The resulting portrait is converted into 8-bit grayscale, and for 150×110 pixels among them, the unevenness of the value of each pixel is calculated as the standard deviation value, thereby digitizing the glare. It can be said that the smaller the numerical glare value, the less glare.

<Comparative example>

In each of the anti-glare films of Samples 1 to 7, the back of the anti-glare film was bonded with a transparent adhesive to a glass plate with a thickness of 0.7 mm on which a black matrix with 200 ppi formed on one side was not formed. surface. That is, in samples 1 to 7, the surface of the anti-glare film was separated from the black matrix by 0.76 mm. To the laminate thus obtained, light from a white surface light source (LIGHTBOX manufactured by HAKUBA, average brightness 1000 cd/m ² ) was irradiated from the black matrix side, and the glare was caused by the pseudo-similarity. Take this from the anti-glare film side with a CCD camera (KP-M1, C mount adapter, close-up mount; PK-11A Nikon, camera lens; 50mm, F1.4s NIKKOR). The distance between the CCD camera and the anti-glare film is set to 250 mm, and the focus of the CCD camera is adjusted in accordance with the anti-glare film. The image captured by the CCD camera is taken into a personal computer, and analyzed with image processing software (ImagePro Plus ver.6.2; manufactured by Media Cybernetics) as shown below. First, select the area of 200×160 pixels from the imported portrait, and convert to 16bit gray scale in this area. Next, the low-pass filter is selected by the emphasis label of the filter command, and the filter is applied under the conditions of 3×3, frequency 3, and intensity 10. This removes the components from the black matrix pattern. Next, select flattening, and perform shading correction under the conditions of background: dark, object width 10. Next, the contrast emphasis command is set to contrast: 96, brightness: 48 for contrast emphasis. Convert the resulting image into 8-bit grayscale, and for each of 150×110 pixels, calculate the unevenness of the value of each pixel as the standard deviation value, thereby digitizing the glare.

<Evaluation of glare by visual inspection>

In each anti-glare film of samples 1 to 7, the glare was visually evaluated as follows. It is formed as a white surface light source with a brightness of 1500cd/m ² , a glass plate with a thickness of 0.7mm and a black matrix with 200ppi formed on one side, and the anti-glare film is stacked in this order from the bottom. At a distance of about 30cm, the anti-glare The normal direction of the cellulose triacetate resin film of the film was visually evaluated in a direction inclined 45° to the left and right. Observe the degree of glare, and judge in four stages of 1-4. Here, the order of glare is 1, 2, 3, and 4 in order. That is, the one with the most glare is 1, and the one with the least glare is 4.

The results are shown in Table 1 below.

As shown in Table 1, the results of the glare evaluation method of the comparative example do not correspond to the results of the glare evaluation by visual observation. On the other hand, the result of the glare evaluation method of the embodiment corresponds to the glare evaluation result obtained by visual inspection. With this, by the glare evaluation method of the embodiment, confirm In fact, even if the degree of glare in the anti-glare film is not visually evaluated from an oblique direction, it is possible to evaluate how much glare occurs when the anti-glare film is visually observed from an oblique direction.

10‧‧‧White light source

20‧‧‧Matrix filter

30‧‧‧Anti-glare film

30A‧‧‧Surface

30B‧‧‧Back

31‧‧‧Light transmissive substrate

32‧‧‧Anti-glare layer

40‧‧‧Camera device

50‧‧‧Support board

50A‧‧‧face

60‧‧‧ spacer

80‧‧‧Picture processing device

d‧‧‧Distance

Claims (5)

A method for quantitative evaluation of glare, comprising: a light-transmitting base material, and an anti-glare layer provided on the light-transmitting base material and having an uneven surface, and an anti-glare film having an uneven surface formed on the surface , Which is: the surface of the anti-glare film is separated from the grid-shaped matrix filter arranged on the back side of the anti-glare film by 3.76 mm or more, and the light from the white light source is transmitted through the matrix filter The light sheet enters the anti-glare film from the back side of the anti-glare film, photographs the transmitted light emitted from the surface of the anti-glare film, and takes the transmitted light as an image. Based on the taken image, The standard deviation of the uneven brightness distribution is obtained, the value of the obtained standard deviation is used as a glare value, and the degree of glare that is recognized when the anti-glare film is viewed obliquely is evaluated based on the glare value. As in the method for quantitative evaluation of glare according to item 1 of the patent application range, a light-transmitting spacer is arranged between the matrix filter and the anti-glare film. For example, in the method for quantitative evaluation of glare according to item 1 of the patent application scope, the standard deviation of the uneven brightness distribution is obtained after performing the image processing on the acquired image. For example, in the method of quantitative evaluation of glare in claim 1, the matrix filter is composed of a black matrix. For example, in the method of quantitative evaluation of glare in the first patent application, the above-mentioned photography of transmitted light is performed by a CCD camera.

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