TWI779026B - Touch sensor panel - Google Patents

Abstract

The present invention relates to a touch sensor panel capable of preventing pattern regions and non-pattern regions composing a touch sensor layer from being distinctively recognized, thereby improving the display quality.

Description

Touch Sensor Panel

The present invention relates to a touch sensor panel, and more specifically, to a touch sensor that can prevent the pattern area and non-pattern area constituting the touch sensing layer from being distinguished and recognized, and can improve display quality. tester panel.

When the user touches the image displayed on the screen with fingertips, stylus, etc., the touch sensor is a device that responds to the contact and grasps the touch position. It is installed on the Liquid Crystal Display (LCD) , organic light-emitting diode (Organic Light-Emitting Diode, OLED) and other display devices.

Generally, there is a touch sensing layer in a touch sensor, which includes transparent electrode patterns formed in mutually crossing directions for sensing user touch actions; the touch sensing layer is divided into transparent electrodes. The patterned area of the pattern and the non-patterned area where the transparent electrode pattern does not exist.

Depending on the presence or absence of transparent electrode patterns, the optical properties (including transmittance) of these patterned regions and non-patterned regions will differ from each other, thus creating a disadvantageous situation where the patterned region and the non-patterned region can be distinguished and recognized, resulting in lowered image quality .

prior art literature

patent documents

Patent Document 1: Korean Laid-Open Patent Publication No. 10-2013-0129625

Patent Document 2: Korean Laid-Open Patent Publication No. 10-2015-0107969

The object of the present invention is to provide a film touch sensor that can prevent the phenomenon that these areas are distinguished and recognized by compensating the difference in optical characteristics between the pattern area and the non-pattern area constituting the touch sensing layer, and a film touch sensor including a film touch sensor. touch sensor panel that controls the sensor.

In order to solve such a problem, the present invention provides a touch sensor panel including a cover window for a display device, a pattern area disposed under the cover window and including an electrode pattern formed therein, and The film touch sensor in the non-pattern area between the pattern areas, and the light conversion layer arranged under the film touch sensor; using CIE standard light D65 as the reference light for color measurement, observed at CIE 10° The difference in hue angle (Δh0°) between the patterned area and the non-patterned area is 50° or less when measured from the surface covering the window using the 10D Observer as a reference.

The difference in hue angle between the pattern region and the non-pattern region is more preferably 20° or less.

In addition, the color coordinates on the CIE a*b* color coordinate system of the reflection hue of the above-mentioned pattern area and the above-mentioned non-pattern area are located in the ellipse area satisfying the following formula,

In the above formula, a can be greater than 0 and less than 16, b can be greater than 0 and less than 11.5, h can be 3~3.5, k can be -5~-10.5, θ can be 85°~120°.

The above-mentioned covering window may comprise a covering substrate and at least one functional layer disposed on the covering substrate, and the above-mentioned functional layer may be an anti-reflection (Anti-Reflection) layer, an anti-glare (Anti-Glare) layer, an anti-fouling (Anti- One of a Fouling layer, an anti-scattering (Shatter Proof) layer and an anti-fingerprint (Anti-Fingerprint) layer.

The cover window may further include a diffusion layer disposed between the cover base material and the functional layer.

The above-mentioned light conversion layer may include a polarizing plate and a retardation plate.

The film touch sensor may further include an optical compensation layer for compensating the difference in transmittance between the patterned area and the non-patterned area.

The thickness of the above-mentioned optical compensation layer may be 50 nanometers (nm)~100 nanometers, and the refractive index may be 1.6~2.1.

Optically Clear Adhesive (OCA) can be used to attach the cover window, film touch sensor and light conversion layer to each other.

The touch sensor panel provided by the present invention compensates for the difference in optical characteristics between the patterned area and the non-patterned area constituting the touch sensing layer, so that these areas can no longer be distinguished and identified, thereby improving the display quality .

100: Membrane touch sensor

101: display area

102: Non-display area

110: separation layer

120: The first protective layer

130: optical compensation layer

140: Touch sensing layer

141: the first touch electrode

142: the second touch electrode

143: Bridge

144: electrode pad

145: Sensing line

146:Bond pad

150: second protective layer

200: light conversion layer

210: phase difference plate

220: polarizer

300:Overlay window

310: Covering the base material

320: functional layer

FIG. 1 is a plan view schematically showing a film touch sensor according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view along line II-II' in Fig. 1 .

FIG. 3 is a schematic cross-sectional view of a touch sensor panel according to another embodiment of the present invention, wherein the touch sensor panel is formed by integrally forming a film touch sensor, a cover window and a light conversion layer. .

Fig. 4 is a graph showing the measurement results of reflectance for each wavelength of the cover window included in the touch sensor panel manufactured according to the embodiment of the present invention.

Fig. 5 is a graph showing the measurement results of the reflectance for each wavelength of the circular polarizing plate included in the touch sensor panel manufactured according to the embodiment of the present invention.

Fig. 6 is a graph showing the reflectance measurement results for each wavelength of the cover window included in the touch sensor panel manufactured according to the embodiment of the present invention and the bonded product of the cover window and OCA.

Fig. 7a to Fig. 7c are diagrams showing the measurement results of the reflection hue of the touch sensor panel manufactured according to the embodiment of the present invention.

The present invention will be described in detail below. It should be noted that, when referring to the drawings attached to this specification in describing the present invention, the drawings are merely illustrations for explaining the present invention, and the present invention is not limited by the drawings. In addition, for the convenience of description, some components may be shown exaggeratedly, reduced or omitted in the drawings.

FIG. 1 is a plan view schematically showing the overall shape of a film touch sensor according to an embodiment of the present invention.

Referring to FIG. 1 , the film touch sensor 100 according to an embodiment of the present invention is divided into a display area 101 and a non-display area 102 based on whether to display visual information. In FIG. 1 , the non-display area 102 is clearly shown slightly larger than actual in order to clearly show the components included in the non-display area 102 .

The display area 101 is an area for displaying an image provided by a device combined with a film touch sensor, and is an area for sensing a touch signal input by a user in an electrostatic capacitive manner. Formed in the region are: a plurality of first touch electrodes 141 arranged in a first direction (vertical direction in FIG. 1 ) and connected to each other in a pattern; A plurality of second touch electrodes 142 arranged in a horizontal direction) and connected to each other via bridges 143 .

In the non-display area 102 located around the display area 101, there are formed: a plurality of electrode pads 144 electrically connected to the touch electrodes, a plurality of sensing lines 145 electrically connected to the plurality of electrode pads 144, and the plurality of electrode pads 144. A plurality of bonding pads 146 electrically connected to each sensing line 145. A flexible printed circuit (FPC, Flexible Printed Circuit) (not shown) for transmitting the touch signal sensed in the display area 101 to the driving part (not shown) is connected to the bonding pad 146 .

Fig. 2 is a cross-sectional view along line II~II' in Fig. 1 .

Referring to FIG. 2 , a film touch sensor 100 according to an embodiment of the present invention includes a separation layer 110 , a first protection layer 120 , an optical compensation layer 130 , a touch sensing layer 140 and a second protection layer 150 .

In the process of manufacturing the film touch sensor according to an embodiment of the present invention, the separation layer 110 is a layer formed for peeling off from a hard carrier substrate such as glass. As will be described later, the separation layer 110 covers and wraps the touch sensing layer 140 formed on the upper portion, and at the same time, can function to insulate it.

The raw material of the separation layer 110 is not particularly limited as long as it satisfies the conditions of providing a certain level of release force and transparency. For example, the separation layer 110 can be made of polyimide-based polymers, polyvinyl alcohol-based polymers, polyamic acid-based polymers, polyamide-based polymers , Polyethylene (polyethylene) polymer, polystyrene (polystyrene) polymer, polynorbornene (polynorbornene) polymer, phenylmaleimide copolymer (phenylmaleimide copolymer) polymer, polyiso Nitrobenzene (polyazobenzene) polymers, polyphenylenephthalamide (polyphenylenephthalamide) polymers, polyester (polyester) polymers, polymethyl methacrylate (polymethyl methacrylate) polymers, poly Polyarylate-based polymers, cinnamate-based polymers, coumarin-based polymers, phthalimidine-based polymers, and chalcone-based polymers , aromatic acetylene (aromatic acetylene) polymers and other polymers, these can be used alone or in combination of two or more.

The peeling force of the separation layer 110 is not particularly limited, for example, it can be more than 0.01 Newton/25mm (0.01N/25mm) and less than 1 Newton/25mm, preferably more than 0.01N/25mm and 0.1N/25mm. Below 25mm. If the above range is satisfied, the touch sensor can be easily detached from the carrier substrate without residue during the manufacturing process of the touch sensor, and curl and cracks caused by tension generated during detachment can be reduced.

The thickness of the separation layer 110 is not particularly limited, for example, it may be 10-1000 nm, preferably, it may be 50-500 nm. When the above-mentioned range is satisfied, the peeling force is stable and a uniform pattern can be formed.

The first protection layer 120 is formed between the separation layer 110 and the touch sensing layer 140 , and is an optional constituent element that can be omitted as needed. The first protection layer 120 covers the touch sensing layer 140 together with the separation layer 110 for protection. The first protection layer 120 functions to enable The separation layer 110 is not exposed to the etchant for forming the pattern of the touch sensing layer 140 .

As the raw material of the first protective layer 120, polymers known in the art can be used without particular limitation. The composition is formed and is not limited thereto.

Specific types of polyols include polyether glycol derivatives, polyester glycol derivatives, polycaprolactone glycol derivatives, and the like, and are not limited. on these.

Specific types of melamine curing agents include methoxy methyl melamine derivatives, methyl melamine derivatives, butyl melamine derivatives, isobutoxy Melamine (isobutoxy melamine) derivatives, butoxy melamine (butoxy melamine) derivatives, etc., but not limited to these.

As another example, the first protective layer 120 may be made of an organic-inorganic hybrid curable composition, and the combination of an organic compound and an inorganic compound can reduce cracks during peeling.

The above-mentioned components can be used as the organic compound, and examples of the inorganic compound include silica-based nanoparticles, silicon-based nanoparticles, glass nanofibers, and the like, but are not limited thereto.

The optical compensation layer 130 is formed on the first protective layer 120 and performs the following functions: to compensate the difference in optical characteristics (including the difference in transmittance) between the patterned area and the non-patterned area in the touch sensing layer 140, wherein the patterned area is formed with a transparent electrode pattern , and no transparent electrode pattern is formed in the non-pattern area.

This will be specifically described below.

First, referring to FIG. 1 , the film touch sensor includes: a pattern area in which a first touch electrode 141, a second touch electrode 142, and a bridge 143 area are formed in the display area 101; pattern area.

Referring to FIG. 2, such a patterned area and a non-patterned area are separated in a stacked structure in the up and down direction.

Furthermore, in the case where the optical compensation layer 130 is not interposed therebetween, the non-pattern area B has a structure in which the separation layer 110, the first protection layer 120 and the second protection layer 150 are stacked, and the pattern area A has a structure in which the separation layer 110 is removed. In addition to the first protection layer 120 and the second protection layer 150 , the touch sensing layer 140 (that is, the first touch electrode 141 or the second touch electrode 142 ) is further laminated. In addition, although it is not shown in FIG. 2, in a part of the region, there is a bridge (FIG. 1: 143), or an insulating part (not shown), or both of the bridge and the insulating part are further laminated. structure.

Since they have different lamination structures, the pattern area A and the non-pattern area B have different optical properties from each other. Typically, the two regions may exhibit different transmittances and hues from each other, with the result that a disadvantageous situation arises in that the two regions may be recognized differently by the user.

In the film touch sensor related to the embodiment of the present invention, the optical compensation layer 130 has the following functions: in order to allow the user to distinguish the pattern area A and the non-pattern area B, the optical characteristics of the two areas The difference is compensated.

The thickness of the optical compensation layer 130 may be 50 nm to 100 nm, and the optical compensation layer 130 may be formed of an organic film or an inorganic film.

When the optical compensation layer 130 is an inorganic film, it may contain at least one selected from Al ₂ O ₃ , MgO, NdF ₃ , SiON, Y ₂ O ₃ , ZnO, TiO ₂ , ZrO ₂ , and Nb ₂ O ₅ .

In the case where the optical compensation layer 130 is an organic film, it can be made of more than one selected from Al ₂ O ₃ , MgO, NdF ₃ , SiON, Y ₂ O ₃ , ZnO, TiO ₂ , ZrO ₂ , and Nb ₂ O ₅ Organic insulating film formation of inorganic particles. In this case, the content of the inorganic fine particles may be 40 parts by weight or more and 95 parts by weight or less based on the total weight of the optical compensation layer. By adjusting the content of the inorganic particles, the refractive index of the optical compensation layer can be adjusted.

In addition, the organic matter may contain one or more selected from acrylic resins, polyurethane resins, melamine resins, alkyd resins, siloxane polymers, and organosilane condensates, and the inorganic particles may contain Al ₂ One or more of O ₃ , MgO, NdF ₃ , SiON, Y ₂ O ₃ , ZnO, TiO ₂ , ZrO ₂ , and Nb ₂ O ₅ .

The average dispersed particle diameter of the inorganic fine particles may be 10 nm or more and 200 nm or less.

It can be constituted in the following way: the refractive index of the optical compensation layer 130 is greater than the refractive index of the first protective layer 120 and smaller than the refractive index of the transparent electrode pattern constituting the touch sensing layer 140. As a specific example, the refractive index of the optical compensation layer 130 The ratio may be not less than 1.6 and not more than 2.1, more preferably not less than 1.6 and not more than 1.8. If configured in this way, the optical compensation layer 130 between the first protection layer 120 and the touch sensing layer 140 has a refractive index between the first protection layer 120 and the touch sensing layer 140. The refractive index of the first protection layer 120 and the touch-sensing layer 140 can prevent light loss caused by a sharp difference in refractive index. If the refractive index is less than 1.6, there is a problem that the transmittance of the non-pattern region increases and visibility increases. If the refractive index exceeds 2.1, there is a problem that the transmittance of the non-pattern area decreases to increase the visibility. In addition, if the thickness of the optical compensation layer 130 is too thin, it will be difficult to control the thickness uniformity during the film forming process.

The touch sensing layer 140 is formed on the optical compensation layer 130 and is a constituent element for sensing a touch signal input by a user.

The sensing pattern constituting the touch sensing layer 140 can be formed into an appropriate pattern according to the requirements of the applied electronic device. The y-coordinate pattern is formed of these two patterns, but is not limited thereto.

For example, as shown in FIG. 1 , the touch sensing layer 140 may include a first touch electrode 141 , a second touch electrode 142 , an insulating part (not shown) and a bridge 143 .

Further referring to FIG. 1 , the first touch electrodes 141 are formed along the vertical direction while being electrically connected to each other, and the second touch electrodes 142 are formed along the horizontal direction while being electrically separated from each other.

In order to electrically insulate between the first touch electrode 141 and the second touch electrode 142, an insulating part is formed between the first touch electrode 141 and the second touch electrode 142, and the second touch The contact hole (not shown) where a part of the electrode 142 is exposed, and the bridge 143 formed on the insulating portion electrically connects the adjacent second touch electrodes 142 through the contact hole.

As the material for forming the first touch electrode 141, the second touch electrode 142, and the bridge 143, as long as it is a transparent conductive substance, it can be used without limitation, for example, it can be formed from a material selected from the following: selected from indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), fluorine doped tin oxide (FTO), indium tin Oxide-Silver-Indium Tin Oxide (ITO-Ag-ITO), Indium Zinc Oxide-Silver-Indium Zinc Oxide (IZO-Ag-IZO), Indium Zinc Tin Oxide-Silver-Indium Zinc Tin Oxide ( Metal oxides in IZTO-Ag-IZTO) and aluminum zinc oxide-silver-aluminum zinc oxide (AZO-Ag-AZO); selected from gold (Au), silver (Ag), copper (Cu), molybdenum Metals in (Mo) and APC; metal nanowires selected from gold, silver, copper and lead; carbon series materials selected from carbon nanotubes (CNT) and graphene (graphene); and selected Conductive polymer substances from poly(3,4-dioxyethylthiophene) (PEDOT) and polyaniline (PANI), these can be used alone or in combination of two or more, preferably, can be used indium tin oxide. Either crystalline or amorphous indium tin oxide can be used.

The resistance of the touch sensing layer 140 may be below 40Ω/□.

The thickness of the touch-sensing layer 140 is not particularly limited, and it is preferably as thin as possible when considering the flexibility of the film touch sensor. For example, the thickness of the touch sensing layer 140 may be 100 nm to 150 nm.

The first touch electrodes 141 and the second touch electrodes 142 constituting the touch sensing layer 140 can each independently be a polygonal pattern such as a triangle, a quadrangle, a pentagon, a hexagon, or a heptagon.

In addition, the touch sensing layer 140 may include regular patterns. The so-called regular pattern means that the shape of the pattern is regular. For example, the pattern of the touch-sensing layer 140 may independently include a rectangular or square mesh pattern, or a hexagonal pattern.

Alternatively, the touch sensing layer 140 may include irregular patterns. The irregular pattern means that the form of the pattern does not have regularity.

On the other hand, when the pattern constituting the touch sensing layer 140 is formed of materials such as metal nanowires, carbon-based materials, polymer materials, etc., the pattern of the touch sensing layer 140 may have a network structure. In the case where the pattern has a network structure, a signal is sequentially transmitted to the patterns adjacent to each other in contact, so a pattern with high sensitivity can be realized.

The pattern constituting the touch sensing layer 140 may be formed of a single layer or a plurality of layers.

As the raw material of the insulating part used to electrically insulate the first touch electrode 141 and the second touch electrode 142, any insulating material known in the art can be used without particular limitation. Oxide (such as oxide of silicon) or photosensitive resin composition containing acrylic resin, or thermosetting resin composition. Alternatively, the insulating portion may be formed of an inorganic substance such as silicon oxide (SiOx), and in this case, it may be formed by vapor deposition, sputtering, or the like.

The second protective layer 150 is formed of an insulating material, and covers the first touch electrodes 141, the second touch electrodes 142, the insulating part, and the bridge 143 that constitute the touch sensing layer 140, so as to make the touch sensing layer 140 and The function of external insulation and protection.

The second protection layer 150 is formed in a planarized manner on the surface opposite to the surface contacting the touch sensing layer 140 .

In addition, the second protective layer 150 may be formed of a single layer or a plurality of layers of two or more layers.

As the raw material of the second protective layer 150, as long as it is an insulating material known in the art, it can be used without particular limitation. For example, a photosensitive material containing metal oxide (such as silicon oxide) or acrylic resin can be used. permanent resin composition, or a thermosetting resin composition can be used.

On the other hand, according to another embodiment of the present invention, the touch sensor panel can be provided in the following form: the film touch sensor is integrally formed with the cover window and the light conversion layer covering the film touch sensor, The light conversion layer converts the polarization direction and phase of the light and outputs it.

FIG. 3 is a cross-sectional view of a touch sensor panel according to another embodiment of the present invention, wherein the touch sensor panel integrates a film touch sensor, a cover window and a light conversion layer.

Referring to FIG. 3, the light conversion layer 200 is attached to the lower portion of the film touch sensor 100, The cover window 300 is attached to the upper portion of the film touch sensor 100 .

The film touch sensor 100 may be the film touch sensor 100 related to an embodiment of the present invention described in detail with reference to the foregoing FIG. 1 and FIG. 2 .

The light conversion layer 200 is a layer capable of converting and outputting the polarization direction and phase of light passing therethrough, and may include a polarizer 220 and a retardation plate 210 .

In the embodiment shown in FIG. 3, the light conversion layer 200 is attached to the lower part of the film touch sensor 100, but the present invention is not necessarily limited thereto, and the light conversion layer can also be attached to the film touch sensor the upper part on which the cover window is attached. Furthermore, when the light conversion layer 200 is attached to the lower part of the film touch sensor 100, the distance between the user's fingertips in contact with the touch sensor during the touch operation is short, so the static electricity generated by the touch The increase in capacity variation is beneficial to the improvement of touch performance.

In the case where the light conversion layer 200 includes the polarizing plate 220, the light conversion layer 200 can convert transmitted light into polarized light and output it. The polarizing plate 220 may include a transmission axis and an absorption axis. With respect to light irradiated on the polarizing plate 220, the polarizing plate 220 can transmit light polarized in a direction parallel to the transmission axis and absorb the remaining light, so that polarized light can be output.

When the light conversion layer 200 includes the phase difference plate 210, the light conversion layer 200 can convert the phase of transmitted light and output it. The phase difference plate 210 may be a QWP that only retards incident light by λ/4. With the retardation plate 210 , when circularly polarized light enters the retardation plate 210 , it can be converted into linearly polarized light; when linearly polarized light is incident, it can be converted into circularly polarized light.

The light conversion layer 200 may include the polarizing plate 220 or the retardation plate 210 , or may include both the polarizing plate 220 and the retardation plate 210 .

The light conversion layer 200 may have a thickness of 25 micrometers (μm)˜75 μm. The polarizing plate 220 may have a thickness of 15 microns to 50 microns, and the phase difference plate 210 may have a thickness of 10 microns to 25 microns.

Alternatively, the light conversion layer 200 may have a thickness of 5 micrometers to 250 micrometers, and the polarizing plate 220 may have a thickness of 5 micrometers to 100 micrometers.

If the thickness of the polarizing plate 220 is less than 5 micrometers, handling between process shifts is not easy, and the possibility of defects in the process increases. Conversely, if the thickness of the polarizing plate 220 exceeds 100 μm, the stress acting upon bending increases, and there is a problem that cracks may occur in the polarizing plate 220 when repeatedly bent. In addition, unlike the illustration in Fig. 3, when the light conversion layer is attached to the upper part of the film touch sensor, the distance between the fingertip in contact with the touch sensor becomes longer, and touch may occur. The problem of degraded control performance.

Therefore, by forming the polarizing plate 220 with a thickness of 5 micrometers to 100 micrometers, it is possible to reduce process defects or damage defects, and has the effect of improving manufacturing yield.

As the polarizing plate 220, a polarizing plate dyed as necessary can be used.

In addition, the transmittance of the polarizing plate 220 can be appropriately selected according to needs.

The phase difference plate 210 may have a thickness of 10 microns to 150 microns.

If the thickness of the phase difference plate 210 is less than 10 micrometers, the handling between process shifts is not easy, and the possibility of defects in the process increases.

If the thickness of the phase difference plate 210 exceeds 150 micrometers, the stress acting upon bending becomes large, and there is a problem that cracks may be generated in the phase difference plate 210 during repeated bending. In addition, unlike the illustration in FIG. 3 , when the light conversion layer is attached to the upper part of the film touch sensor, the distance between the fingertip in contact with the touch sensor becomes longer, which may cause Touch performance degradation issue.

Therefore, by forming the phase difference plate 210 with a thickness of 10 micrometers to 150 micrometers, it is possible to reduce process defects or damage defects, and has the effect of improving manufacturing yield. In addition, there is also an effect of being able to improve touch sensitivity.

The cover window 300 is a layer that protects the film touch sensor 100 from scratches or external impacts, and generally includes at least a cover substrate 310 made of tempered glass, and may further include more than one functional layer 320 .

According to an embodiment of the present invention, the cover substrate 310 is a transparent substrate, which may be glass or a film. As the covering base material, any material can be used without particular limitation as long as it has necessary properties such as transparency, lightness, impact resistance, scratch resistance, and processability.

The functional layer 320 can be formed by an organic film or an inorganic film, and can include an anti-reflection (Anti-Reflection) layer, an anti-glare (Anti-Glare) layer, an anti-fouling (Anti-Fouling) layer, an anti-scattering (Shatter Proof) layer, an anti-fingerprint At least one of the (Anti-Fingerprint) layers.

The functional layer 320 may be formed to have a different refractive index from that of the cover substrate 310 .

In addition, a diffusion layer may be further formed between the functional layer 320 and the cover substrate 310 , and in this case, the diffusion layer may be formed by roughening or an organic film layer containing particles.

When the light conversion layer and cover window are attached to the film touch sensor, the optical characteristics of the touch sensor panel display may be changed due to further stacked layers. Especially, as shown in FIG. 3, when the light conversion layer 200 is attached to the lower part of the film touch sensor 100 in order to improve the touch performance, the reflected light does not pass through the light conversion layer 200. Influenced by the hue of each constituent element of the sensor panel, for the user, the pattern area and the non-pattern area of the film touch sensor 100 can be easily distinguished and recognized.

Therefore, in another embodiment of the present invention, in the state where the user finally uses the display device, that is, in the state where the cover window and the light conversion layer are attached to the film touch sensor, through the control touch sensor The reflective hue of the panel makes it difficult for the user to distinguish and recognize the pattern area and the non-pattern area of the film touch sensor, which can improve the display characteristics of the display device.

Specifically, using CIE standard light D65 as the reference light for color measurement, when measuring from the surface covering the window with the CIE 10° observer (10D Observer) as the reference, the CIE a*b of the reflection hue of the pattern area and the non-pattern area *Coordinates on the color coordinate system are located within an ellipse region satisfying the following formula.

In the above formula, a is greater than 0 and less than 16, b is greater than 0 and less than 11.5, h is 3 to 3.5, and k is -5 to -10.5. Also, θ may be 85° to 120°.

In addition, the difference Δh0° of the hue angle (Hue Angle) formed by the color coordinates of the patterned area and the non-patterned area is less than 50°, more preferably less than 20°.

Therefore, the optical characteristics of the patterned area and the non-patterned area, especially the reflection hue, become similar, and the user cannot visually distinguish the patterned area and the non-patterned area.

Examples and comparative examples are given below to describe the present invention more specifically. It should be noted that these Examples and Comparative Examples are merely for illustrating the present invention, and it is obvious to those skilled in the art that the scope of the present invention is not limited by them.

First, creation of an overlay window will be described.

As for the cover window, two types of cover windows including a diffusion layer and a cover window without a diffusion layer were produced, and the reflectance was measured, and an organic thin film was formed on both cover windows.

Fig. 4 shows the reflectance measurement results for each wavelength of the produced cover window, which were measured using a ST4000 measuring instrument manufactured by K-MAC Corporation.

Next, a circular polarizing plate was produced as a light conversion layer. The circular polarizing plate is produced by bonding a polarizing plate (manufactured by Toyu Fine Chemical Co., Ltd.) with a transmittance of 43% and a 1/4 lambda retardation film (manufactured by Fuji Corporation) with a pressure-sensitive adhesive, also using K-MAC Co., Ltd. The manufactured ST4000 measuring instrument measured the reflectance of the polarizing plate surface of the manufactured circular polarizing plate, and the results are shown in Fig. 5 .

For film touch sensors, multiple touch sensing layers and optical compensation layers with different thicknesses are fabricated. Specifically, the touch sensing layer is formed of ITO with a thickness of 110 nm to 140 nm, and the optical compensation layer is formed of a material having a refractive index of 1.6 to 1.68 with a thickness of 40 nm to 90 nm. The characteristics of the touch-sensing layer and the optical compensation layer of each embodiment and each comparative example will be described later.

After the optically clear adhesive (OCA, Optically Clear Adhesive) is used to attach the produced cover window, film touch sensor and circular polarizing plate, the reflectance of OCA is measured by measuring the reflectance of the cover window and the joint between the cover window and OCA Confirmed by the reflectivity. The measurement results are shown in Fig. 6 .

Figs. 7a to 7c are diagrams showing the measurement results of reflection hue of the touch sensor panel produced in this way. For the cover window, a cover window not containing a diffusion layer was used, and as the light conversion layer, the above-mentioned circular polarizing plate was used. The measurement results are shown on the CIE a*b* color coordinate system, and are the results measured by a 10° observer using D65 standard light.

From Figure 7a to Figure 7c, the part displayed with red squares represents the pattern area, and the part displayed with blue diamonds represents the coordinates on the color coordinate system of the non-pattern area, and Figures 7a to 7c will limit the ellipse area The values of a, b, h, k, and θ are shown in the accompanying drawings together, and these elliptical areas meet the conditions that the color difference (△a*b*) is less than 8, less than 12, and less than 14, respectively.

As shown in the attached figure, a is below 16, b is below 11.5, h is 3~3.5, and k is -5~-10.5. Moreover, when θ is 85°-120°, the positions of the color coordinates of the patterned area and the non-patterned area are sufficiently close and the two areas display similar hues, so the user cannot distinguish and recognize the two areas.

In Table 1 below, the difference Δh0° in hue angle (Hue Angle) was measured while changing the thickness of the touch sensing layer, the thickness of the optical compensation layer, and the refractive index, and shows the results of visual evaluation based on the difference in hue angle. Visual evaluation refers to the degree to which the patterned area and the non-patterned area of the touch sensor panel can be distinguished and recognized by human eyes.

In the case of the comparative example, the thickness of the touch sensing layer was 120 nm, the thickness of the optical compensation layer was 50 nm, the refractive index was 1.6, and Δh0° was as high as 51.53°. Patterned areas can be clearly distinguished and identified from non-patterned areas.

In the case of Example 1, the thickness of the touch sensing layer is 122 nanometers, the thickness of the optical compensation layer is 80 nanometers, and the refractive index is 1.62, showing Δh0° of 20.14°. In visual evaluation, it can be Moderate discrimination between patterned and non-patterned areas.

In the case of Examples 2, 3, 6, and 7, 9.59°, 8.58°, 5.33°, and 4.37° of Δh0° are shown respectively, and the pattern area and the non-pattern area can be identified weakly; in Examples 4 and 5 In the case of , the △h0° of 0.71° and 0.55° were respectively displayed, and the pattern area and the non-pattern area could not be distinguished, showing uniform visibility.

In the above-mentioned embodiments, the thickness of the touch sensing layer, the thickness of the optical compensation layer and the refractive index are changed to measure △h0°, and a visual evaluation is carried out based on △h0°. The parameters affecting △h0° include touch sensing In addition to the thickness of the layers, the thickness of the optical compensation layer and the refractive index, there may be various parameters. Examples include: the type and thickness of the functional layer contained in the cover window; the type and thickness of the adhesive used to attach the cover window, film touch sensor, and light conversion layer; the hue and transmittance of the polarizing plate etc., but not limited to these.

Therefore, it should be fully understood that the value of Δh0° can also be appropriately adjusted by changing the thickness of the touch sensing layer, the thickness of the optical compensation layer, and other parameters other than the refractive index according to needs, and such changes are included in the present invention In the range.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-mentioned embodiments, and it can be understood that the present invention can be embodied in modified forms within the range of characteristics that do not deviate from the essence of the present invention. The embodiments of the present invention described above can be applied independently or in combination of some or all of their features.

Therefore, the scope of the present invention is defined not by the above description but by the claims, and all differences within the equivalent range should be construed as being included in the present invention.

100‧‧‧Membrane touch sensor

200‧‧‧light conversion layer

210‧‧‧Phase plate

220‧‧‧polarizer

300‧‧‧overlay windows

310‧‧‧covering substrate

320‧‧‧Functional layer

Claims (10)

A touch sensor panel, comprising: a cover window for a display device, a film touch sensor disposed under the cover window and including a pattern area formed with an electrode pattern and a non-pattern area between the pattern areas , and the light conversion layer arranged at the lower part of the film touch sensor; when using CIE standard light D65 as the reference light for color measurement, and taking the CIE 10° observer as a reference to measure from the surface covering the window, the pattern area The hue angle difference (△h0°) from the non-pattern area is 50° or less, wherein the color coordinates on the CIE a*b* color coordinate system of the reflection hue of the pattern area and the non-pattern area are located in an ellipse satisfying the following formula Inside:

In this formula, a is greater than 0 and less than 16, b is greater than 0 and less than 11.5, h is 3 to 3.5, k is -5 to -10.5, and θ is 85° to 120°. The touch sensor panel as claimed in claim 1, wherein the difference in hue angle between the pattern area and the non-pattern area is less than 20°. The touch sensor panel as claimed in claim 1, wherein the cover window comprises a cover substrate and at least one functional layer disposed on the cover substrate. The touch sensor panel as described in claim 3, wherein the functional layer is an anti-reflection (Anti-Reflection) layer, an anti-glare (Anti-Glare) layer, an anti-fouling (Anti-Fouling) layer, an anti-scattering ( Shatter Proof) layer, and one of anti-fingerprint (Anti-Fingerprint) layer. The touch sensor panel as claimed in claim 3, wherein the cover window further includes a diffusion layer disposed between the cover substrate and the functional layer. The touch sensor panel as claimed in claim 1, wherein the light conversion layer includes a polarizer and a retardation plate. The touch sensor panel as claimed in claim 1, wherein the film touch sensor further comprises an optical compensation layer for compensating the difference in transmittance between the pattern area and the non-pattern area. The touch sensor panel as claimed in claim 7, wherein the thickness of the optical compensation layer is 50 nanometers (nm)˜100 nanometers. The touch sensor panel as claimed in claim 7, wherein the optical compensation layer has a refractive index of 1.6˜2.1. The touch sensor panel of claim 1, wherein the cover window, film touch sensor and light conversion layer are attached to each other using an optically clear adhesive (OCA).

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