Glass plate and method for producing same, in-vehicle display device, and method for selecting glass plate

Abstract

The present invention relates to a glass plate having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure on at least a portion thereof, the visibility index value T on the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or more, the glare index value S is 0.80 or more, the average dynamic friction coefficient COF is 0.50 or less, the friction change amount delta is more than -0.210, and the lightness L* value is 4.7 or less.

Description

Glass plate and manufacturing method thereof, in-vehicle display device, and method for selecting a glass plate

[0001] The present invention relates to a glass plate and a method for manufacturing the same, an in-vehicle display device, and a method for selecting a glass plate.

[0002] 2. Description of the Related Art Generally, a cover made of a transparent substrate such as a glass plate is disposed on the display surface side of a display device such as an LCD (Liquid Crystal Display) device in order to protect the display device.

[0003] However, when such a transparent substrate is installed on a display device, reflections of surrounding objects often occur when attempting to view the display image of the display device through the transparent substrate. When such reflections occur on the transparent substrate, the viewer of the display image has difficulty viewing the display image and is left with an unpleasant impression. In particular, in the case of a cover glass for an in-vehicle display device, the distance between the driver and the display device is fixed. Therefore, when a strong light source, such as sunlight, is reflected, it becomes extremely difficult to view the display image, making it difficult to read necessary information, which is likely to interfere with driving.

[0004] Therefore, in order to suppress such reflections, for example, a method of performing an anti-glare treatment to form an uneven shape on the surface of a transparent substrate has been adopted.

[0005] In response to these issues, Patent Document 1 discloses a method for evaluating reflections on a display device using a special device. However, the optical properties required for a cover glass or the like in an in-vehicle display device are not limited to reducing reflections. In other words, the cover glass in an in-vehicle display device is required to have predetermined levels of optical properties in terms of resolution or visibility, reflected image diffusion, glare, and the like. Therefore, when selecting a transparent substrate such as a glass plate, it is insufficient to consider only one optical property, and it is often necessary to consider multiple optical properties simultaneously.

[0006] Therefore, Patent Document 2 discloses that when evaluation is performed using three index values, namely, a resolution index value T, a reflected image diffusion index value R, and a glare index value S, if these index values ​​satisfy specific ranges, a glass plate having resolution, reflected image diffusion, and glare prevention properties suitable for use in an in-vehicle display device can be obtained.

[0007] Furthermore, Patent Document 3 discloses that a glass plate having excellent color reproducibility can be obtained by satisfying specific ranges for the visibility index value T, the reflected image diffusion index value R, and the glare index value S, as well as the transmission haze.

[0008] Japanese Patent Publication No. 2007-147343 Japanese Patent No. 5867649 Japanese Patent No. 7067077

[0009] In contrast to the above, the cover glass of an in-vehicle display device is not only visually recognized but also touched as a touch panel, and this opportunity is expected to increase in the future. As an index for evaluating the tactile feel of a touch panel, for example, as disclosed in Non-Patent Document 1, arithmetic mean roughness and dynamic friction coefficient are used.

[0010] However, the inventors' investigations have revealed that the arithmetic mean roughness and dynamic friction coefficient alone are insufficient as indicators of actual tactile sensation. Therefore, the inventors have investigated a new method for quantitatively evaluating tactile sensation, focusing particularly on swiping. Therefore, the present invention aims to provide a glass plate that maintains good visibility while also providing an excellent tactile sensation during swiping, and a method for manufacturing the same. Another object of the present invention is to provide an in-vehicle display device using the glass plate and a method for selecting the glass plate.

[0011] As a result of intensive research into the above-mentioned problems, the inventors have come to the realization that, in addition to the coefficient of dynamic friction, the change in friction at the end of the swipe when stopping the swipe is important during the swiping motion, and have thus completed the present invention. Furthermore, in order to achieve the desired change in friction, the shape of the outermost surface of the glass plate is important, and they have also discovered a method for achieving this shape.

[0012] That is, the present invention relates to the following [1] to

[19] . [1] A glass plate having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface has a concave-convex structure on at least a part thereof, and the outermost surface of the region on the first main surface side having the concave-convex structure has a visibility index value T of 0.85 or more, a glare index value S of 0.80 or more, an average dynamic friction coefficient COF of 0.50 or less, and a friction change amount delta of more than -0.210, and the lightness L of the glass plate measured by a specularly excluded (SCE) method in accordance with a method in accordance with ASTM E313-73 standard. ＊ The visibility index value T, the glare index value S, the average dynamic friction coefficient COF, and the friction change delta are each quantified by the following method. Visibility index value T: Using an SMS-1000 manufactured by DM&S, the glass plate is placed at a position 30 mm above a slit-shaped white light source having a length of 40 mm and a width of 0.1 mm, with the first principal surface side facing the light source, and the luminance of the outermost surface of the region having the uneven structure is measured from the second principal surface side of the glass plate. A camera lens with a focal length of 16 mm is used with an aperture of 5.6, and the distance from the outermost surface of the first principal surface side of the glass plate to the camera lens is set to 550 mm. An angle θ = 0° is defined as a direction parallel to the thickness direction of the glass plate, and the average luminance in the range of angle θ = 0° ± 0.1° is measured as T. １ The average value of the luminance in the range of angle θ=0.7°±0.1° is T ２ The average value of the luminance in the range of angle θ = −0.7°±0.1° is T ３ In this case, the value calculated by the following formula (1) is defined as the visibility index value T. ２ +T ３ ) / (2 x T １Glare index value S: The glass plate is arranged so that the second main surface is in contact with the display surface side of a display device with a resolution of 264 ppi. With a green monochrome image composed of RGB (0, 255, 0) displayed on the display device, the sparkle value on the outermost surface of the region having the uneven structure, which is determined by image analysis using an SMS-1000 manufactured by DM&S Co., Ltd., installed on the first main surface side of the glass plate, is used as the glare index value S. ａ The distance d between the SMS-1000 manufactured by DM&S and the outermost surface of the first main surface side of the glass plate was set to 540 mm, and the camera lens used had a focal length of 50 mm and an aperture of 5.6. In addition, as a reference sample, image analysis was also performed under the same conditions on a glass substrate (VRD140 glass; manufactured by AGC Glass Europe) having the same thickness as the glass plate, and the obtained Sparkle value was used as the glare S. ｓ Let's say. ａ and S ｓ The value calculated from the value of (S) using the following formula (2) is defined as the glare index value S. ａ / S ｓ) Equation (2) Average dynamic friction coefficient COF, friction change delta: In a static and dynamic friction measuring device, the dynamic friction coefficient is measured by sliding an artificial finger on the outermost surface of the region having the uneven structure on the first main surface side of the glass plate at a scanning distance of 50 mm, a load of 100 g, and a scanning speed of 100 mm / sec in an environment of room temperature 23°C and humidity 21%. The data acquisition frequency is 1 kHz. The artificial finger is made of urethane, and the contact portion with the outermost surface has linear convex portions formed at 0.5 mm intervals in an area of ​​10 x 15 mm, in a direction perpendicular to the sliding direction. Here, counting back from the time when the dynamic friction coefficient is at its maximum, the time when the dynamic friction coefficient first becomes 0 or less is defined as the movement start time, and the time when the dynamic friction coefficient first becomes 5 or less after the time expressed by {(the movement start time) + (0.75 × the scanning distance / the scanning speed)} is defined as the movement end time. The value calculated by the following formula (3) is defined as the average dynamic friction coefficient COF, and the value calculated by the following formula (4) is defined as the friction change amount delta. Average dynamic friction coefficient COF = average value of dynamic friction coefficients at (an intermediate time between the movement start time and the movement end time) ± 0.2 seconds Formula (3) Friction change amount delta = (maximum dynamic friction coefficient after the movement end time) - (the average dynamic friction coefficient COF) Formula (4)

[0013] [2] The first main surface further has an anti-reflection film on at least a portion thereof, the anti-reflection film covering at least a portion of the uneven structure, the luminous transmittance measured at the outermost surface of the first main surface side of the region of the glass plate having the anti-reflection film is 20 to 85%, and the luminous transmittance of the region of the glass plate having the anti-reflection film measured in accordance with JIS Z 8729 (2004) in transmitted color under a D65 light source is 20 to 85%. ＊ a luminous reflectance measured on the outermost surface on the first principal surface side of the region of the glass plate having the antireflection film covering the concave-convex structure is 1% or less, and a sheet resistance of the antireflection film is 10 ４[3] The glass plate according to [2], wherein the outermost surface of the region on the first main surface side having the unevenness structure and the antireflection coating has a transmission haze of 15% or more as measured by a method in accordance with JIS K 7136 (2000). [4] The glass plate according to [2] or [3], wherein the antireflection coating has a laminated structure in which two or more dielectric layers having different refractive indices are alternately laminated, each of the dielectric layers in the laminated structure being mainly composed of at least one oxide selected from the group consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, or at least one nitride of Si and Al, and at least one of the dielectric layers has dispersed therein at least one fine particle selected from the group consisting of Ag, Mo, W, Cu, Au, Pd, Pt, Ir, Ni, Co, Fe, Cr, C, TiC, SiC, TiN, and CrN. [5] The glass plate according to any one of [2] to [4], wherein the antireflection film has a laminated structure in which two or more layers having different refractive indices are alternately laminated, at least one of the layers in the laminated structure is mainly composed of an oxide of Si, and at least one other of the layers in the laminated structure is mainly composed of a mixed oxide of at least one oxide selected from Group A consisting of Mo and W, and at least one oxide selected from Group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, and the content of the element in Group B in the mixed oxide relative to the total of the element in Group A and the element in Group B is less than 50 mass%. [6] The glass plate according to any one of [2] to [5], wherein, on the outermost surface of a region on the first main surface side having the uneven structure and the antireflection film, the surface roughness is such that the element mean length Rsm of a roughness curve is less than 26 μm, the arithmetic mean roughness Ra is 0.12 μm or more, the skewness Rsk is −1 to 1, and the kurtosis Rku is 2 to 4.

[0014] [7] The glass plate according to [1] above, wherein the outermost surface of the region having the concave-convex structure on the first main surface side has a transmission haze of less than 15% as measured by a method in accordance with JIS K 7136 (2000). [8] The glass plate according to [1] above or [7] above, wherein the outermost surface of the region having the concave-convex structure on the first main surface side has a surface roughness in which the element mean length Rsm of the roughness curve is 26 μm or more, the skewness Rsk is −4 to −1.5, and the kurtosis Rku is 5 to 20. [9] The first main surface further has an antireflection film on at least a portion thereof, the antireflection film covering at least a portion of the concave-convex structure, the antireflection film having a layered structure in which two or more low-refractive-index layers and two or more high-refractive-index layers are alternately stacked, and the high-refractive-index layer is mainly composed of SiN, TiO ２ , Nb ２ O ５ , Ta ２ O ５ and ZrO ２ The glass plate according to [1], [7] or [8] above, wherein the glass plate is at least one selected from the group consisting of:

[0015]

[10] The glass plate according to any one of [1] to [9] above, having a printed layer on at least a part of the second main surface.

[11] The glass plate according to any one of [1] to

[10] above, wherein the glass plate is chemically strengthened glass.

[12] The glass plate according to any one of [1] to

[11] above, used as a cover glass for an in-vehicle display device.

[13] An in-vehicle display device, comprising: a cover glass and a display panel made of the glass plate according to

[12] above.

[0016]

[14] The method for producing a glass plate according to any one of [1] to

[12] , wherein the glass plate has a first main surface and a second main surface opposite to the first main surface, and the method comprises forming a concave-convex structure on at least a portion of the first main surface.

[15] The method for producing a glass plate according to

[14] , wherein the formation of the concave-convex structure comprises immersing the glass plate in a solution containing potassium fluoride and hydrogen fluoride, and then immersing the glass plate in a solution containing hydrogen fluoride, and the method further comprises forming an antireflection film so as to cover at least a portion of the concave-convex structure.

[16] The method for producing a glass plate according to

[14] , wherein the formation of the concave-convex structure comprises spraying a slurry onto the first main surface of the glass plate to roughen it, and then immersing the glass plate in a solution containing hydrogen fluoride to etch it.

[17] The method for producing a glass plate according to

[16] , wherein the spray angle of the slurry with respect to the first main surface is 70° or less.

[18] The method for producing a glass plate according to

[16] or

[17] , wherein forming the concave-convex structure comprises immersing the glass plate in a solution containing potassium fluoride and hydrogen fluoride, and then immersing the glass plate in a solution containing hydrogen fluoride, and further comprises forming an anti-reflection film so as to cover at least a part of the concave-convex structure.

[0017]

[19] A method for selecting a glass plate according to any one of [1] to

[12] above.

[0018] According to the present invention, there are provided a glass plate that maintains good visibility and has an excellent tactile feel during a swipe operation, a method for manufacturing the same, an in-vehicle display device using the glass plate, and a method for selecting the glass plate.

[0019] Fig. 1 is a schematic diagram showing an example of a measuring device used when measuring a visibility index value T. Fig. 2 is a schematic diagram showing an example of a measuring device used when measuring a glare index value S. Fig. 3 is a schematic diagram showing an example of a measuring device used when measuring a reflected image diffuseness index value R.

[0020] The present invention will be described in detail below. In this specification, the term "to" indicating a range of values ​​is used to mean that the values ​​before and after it are included as the lower limit and upper limit.

[0021] <Glass Plate> The glass plate according to the present invention has a first main surface and a second main surface opposite the first main surface, and the first main surface has an uneven structure at least partially. The visibility index value T at the outermost surface of the area having the uneven structure on the first main surface side is 0.85 or more, and the glare index value S is 0.80 or more. The average dynamic friction coefficient COF at the outermost surface is 0.50 or less, and the friction change delta is greater than -0.210. Furthermore, the lightness L of the glass plate measured by a specular elimination (SCE) method in accordance with ASTM E313-73 standard is 0.85 or more. ＊ The value is 4.7 or less.

[0022] <Average dynamic friction coefficient COF, friction change delta> The average dynamic friction coefficient COF at the outermost surface of the region having a concave-convex structure, which is the first main surface side of the glass plate according to this embodiment, is 0.50 or less, and the friction change delta is greater than -0.210. Here, the average dynamic friction coefficient COF and friction change delta are values ​​derived by the following measurement methods, respectively. Note that, as the average dynamic friction coefficient COF and friction change delta in this specification, it is preferable to use the average value measured at any three points on the diagonal line. However, as any measurement point, points with extreme outliers are excluded.

[0023] (Measurement Method) Using a static and dynamic friction measuring device, the dynamic friction coefficient is measured by sliding a dummy finger on the outermost surface of the region having a concave-convex structure on the first main surface of a glass plate at a scanning distance of 50 mm, a load of 100 g, and a speed of 100 mm / s at a room temperature of 23°C and a humidity of 21%. The data acquisition frequency is 1 kHz. The dummy finger is made of urethane, and the contact portion with the outermost surface of the glass plate has linear convex portions formed at 0.5 mm intervals in an area of ​​10 x 15 mm, perpendicular to the sliding direction. Here, the time when the dynamic friction coefficient first becomes 0 or less, counting back from the time when the dynamic friction coefficient is maximized, is defined as the movement start time, and the time when the dynamic friction coefficient first becomes 5 or less, after the time expressed by {(the movement start time) + (0.75 x the scanning distance / the scanning speed)}, is defined as the movement end time. The value calculated using the following formula (3) is defined as the average dynamic friction coefficient COF, and the value calculated using the following formula (4) is defined as the friction change delta. Average dynamic friction coefficient COF = (the midpoint between the movement start time and the movement end time) ±0.2 seconds Average value of dynamic friction coefficient Equation (3) Friction change amount delta = (maximum dynamic friction coefficient after the movement end time) - (average dynamic friction coefficient COF) Equation (4) Note that the scanning distance and scanning speed in the equation for calculating the movement end time are 50 mm and 100 mm / sec, respectively, as described as the sliding conditions of the artificial finger.

[0024] The average coefficient of dynamic friction COF is effective for evaluating finger sliding during a swipe operation on the surface of a glass plate, i.e., smoothness. The average coefficient of dynamic friction COF is 0.50 or less, preferably 0.10 to 0.50. Here, from the viewpoint of smooth finger sliding during a swipe operation, the average coefficient of dynamic friction COF is 0.50 or less, preferably 0.45 or less, more preferably 0.40 or less, and even more preferably 0.35 or less. On the other hand, the lower limit of the average coefficient of dynamic friction COF is not particularly limited, but from the viewpoint of providing a swiping operation feel to the user, it is preferably 0.10 or more, more preferably 0.15 or more, and even more preferably 0.20 or more.

[0025] Furthermore, through studies by the present inventors, the floating feeling, such as a weak sense of the finger stopping at the end of a swipe motion on the surface of a glass plate, is correlated with the friction change amount delta, and it has been found that a certain value or more of the friction change amount delta is effective. The friction change amount delta is greater than -0.210, and preferably greater than -0.210 and less than -0.01. Here, from the viewpoint of suppressing the feeling of the finger getting stuck at the end of the swipe motion and realizing a smooth feeling of finger release, the friction change amount delta is greater than -0.210, preferably -0.205 or more, more preferably -0.200 or more, even more preferably -0.15 or more, and even more preferably -0.10 or more. On the other hand, the upper limit of the friction change amount delta is not particularly limited, but from the viewpoint of giving the user the feeling of operation after completing the swipe, it is preferably -0.01 or less, more preferably -0.02 or less, and even more preferably -0.03 or less.

[0026] More specifically, the following combinations of the average coefficient of dynamic friction COF and the amount of change in friction delta are preferred: (i) the average coefficient of dynamic friction COF is 0.35 or less, and the amount of change in friction delta is −0.200 or more; (ii) the average coefficient of dynamic friction COF is 0.40 or less, and the amount of change in friction delta is −0.100 or more. In a more preferred embodiment of the above combinations, the preferred upper and lower limits of the average coefficient of dynamic friction COF and the amount of change in friction delta can be adopted.

[0027] In order for the average dynamic friction coefficient COF and the friction change amount delta to satisfy the above ranges, for example, the shape of the uneven structure on the first main surface side of the glass plate is set to a predetermined range. For example, if the convex portions in the uneven structure on the surface are sharp, contact with the user's finger occurs at multiple discrete points, resulting in a low dynamic friction coefficient and a smooth feel during swiping. On the other hand, by making the uneven structure on the surface finer and shortening the uneven period, and forming many uneven portions, the friction change at the end of the swipe action can be increased, resulting in a smooth feeling of finger slippage. Note that even when an anti-reflective film, anti-fouling film, etc. is formed to cover the uneven structure, the surface structure of the anti-reflective film or anti-fouling film will be a structure that imitates the uneven structure. Therefore, by setting the shape of the uneven structure to a predetermined range, the uneven shape of the outermost surface of the glass plate can be controlled.

[0028] An example of a specific uneven shape on the outermost surface of the glass plate that satisfies the desired ranges of the average dynamic friction coefficient COF and the friction change amount delta will be described later.

[0029] <Visibility Index Value T> In this embodiment, visibility (clarity) represents the degree to which an image obtained matches a displayed image when the displayed image is viewed through a glass plate. This correlates with the result of a viewer's visual judgment of visibility (resolution) and has been confirmed to exhibit behavior similar to human visual perception. For example, a glass plate having a small visibility index value T (close to 0) has poor visibility, while a glass plate having a large visibility index value T has good visibility. Therefore, this visibility index value T can be used as a quantitative index when judging the visibility of a glass plate.

[0030] In this embodiment, the visibility index value T is quantified by the following method. It is preferable to use the average value measured at three arbitrary points on a diagonal line as the visibility index value T in this specification. However, as the arbitrary measurement points, locations with extreme outliers are excluded. An SMS-1000 manufactured by DM&S (Display-Messtechnik & Systeme) is used as the analysis device, and a glass plate is placed 30 mm away from a slit-shaped white light source having a length of 40 mm and a width of 0.1 mm, with the first principal surface side facing the light source. Then, the luminance at the outermost surface of the region having the uneven structure is measured from the second principal surface side of the glass plate. A camera lens with a focal length of 16 mm and an aperture of 5.6 is used, and the distance from the outermost surface of the first principal surface side of the glass plate to the camera lens is set to 550 mm. The angle θ = 0° is defined as the direction parallel to the thickness direction of the glass plate, and the average luminance in the range of angle θ = 0° ± 0.1° is calculated as T. １ The average value of the luminance in the range of angle θ=0.7°±0.1° is T ２ The average value of the luminance in the range of angle θ = −0.7°±0.1° is T ３ In this case, the value calculated by the following formula (1) is defined as the visibility index value T. ２ +T ３ ) / (2 x T １ ) Formula (1)

[0031] More specifically, one embodiment of a method for measuring the visibility index value T of a glass plate 50 will be described with reference to FIG. 1 . A measuring device 70A has a light source 71 and a detector (analysis device) 75, and a sample to be measured, i.e., a glass plate 50, is placed within the measuring device 70A. The glass plate 50 has a first main surface 52 having a concavo-convex structure and a second main surface 53. The light source 71 emits a first light beam from the first main surface 52 side toward the glass plate 50 in a direction parallel to the thickness direction of the glass plate 50, and the luminance of the transmitted light of the first light beam transmitted through the glass plate 50 is detected and analyzed by a detector (analysis device) 75 located on the second main surface 53 side of the glass plate 50.

[0032] The direction parallel to the thickness direction of the glass plate 50 is defined as angle θ=0°, and the average value of the luminance detected in the range of angle θ=0°±0.1° (T １), the average value of the luminance detected in the range of angle θ = 0.7° ± 0.1° (T ２ ) and the average value of the luminance detected in the range of angle θ = −0.7° ± 0.1° (T ３ ), the visibility index value T of the glass plate 50 is calculated by the above formula (1). Note that a minus (-) sign in the angle θ indicates that the angle is inclined counterclockwise with respect to the incident first light, and a plus (+) sign indicates that the angle is inclined clockwise with respect to the incident first light.

[0033] The analyzer used is the SMS-1000 manufactured by DM&S (Display-Messtechnik & Systeme), but if a successor device from DM&S conforming to JIS C1006:2019 is available for this analyzer, this successor device may also be used. Furthermore, the camera lens may be, for example, a C1614A lens (manufactured by Ricoh Co., Ltd.).

[0034] As one of the optical properties of the glass plate according to this embodiment, the visibility index value T at the outermost surface of the region having a concave-convex structure is 0.85 or more, preferably 0.86 or more, more preferably 0.87 or more, and the higher the better. The upper limit of the visibility index value T is 1.0. The visibility index value T can be set to a desired range depending on, for example, the shape and density of the concave-convex structure.

[0035] <Glare Index Value S> In this embodiment, glare (Anti-Sparkle) represents the degree to which light (image) from a displayed image is scattered by the surface of the glass plate when it passes through the glass plate, and the degree to which unevenness of bright spots is observed, which occurs when the scattered light interferes with each other. This correlates with the results of glare judgment by an observer, and has been confirmed to exhibit behavior similar to human visual perception. For example, a glass plate with a small glare index value S tends to exhibit significant glare, while a glass plate with a large glare index value S tends to suppress glare.

[0036] The glare index value S in this embodiment is quantified by the following method. It is preferable to use an average value measured at any three points on a diagonal line as the glare index value S in this specification. However, as any measurement points, points with extreme outliers are excluded. A glass plate is placed so that the second main surface is in contact with the display surface side of a display device with a resolution of 264 ppi. With a green monochromatic image composed of RGB (0, 255, 0) displayed on the display device, the sparkle value at the outermost surface of the region having an uneven structure, which is determined by image analysis using an SMS-1000 manufactured by DM&S installed on the first main surface side of the glass plate, is used as the glare index value S. ａ The distance d between the SMS-1000 manufactured by DM&S and the outermost surface on the first main surface side of the glass plate was set to 540 mm, and the camera lens used had a focal length of 50 mm and an aperture of 5.6. Image analysis was also performed under the same conditions on a glass substrate (VRD140 glass manufactured by AGC Glass Europe) of the same size as the glass plate as a reference sample, and the obtained Sparkle value was used as the glare S. ｓ Let's say. ａ and S ｓ The value calculated from the value of (S) using the following formula (2) is defined as the glare index value S. ａ / S ｓ ) Formula (2) When it is difficult to obtain VRD140 glass as the glass substrate serving as the reference sample, a glass substrate having a Sparkle value of 0.270 to 0.290 is used as the reference sample.

[0037] Here, the reason why a green monochromatic image composed of RGB (0, 255, 0) is displayed on the display device is that it is a color with high visual sensitivity and is easy to see. Furthermore, when the distance d=540 mm between the solid-state imaging element SMS-1000 manufactured by DM&S and the outermost surface on the first main surface side of the glass plate is expressed as a distance index r, it corresponds to r=10.8. The distance index r is expressed by the following formula (2-1) using the focal length f of the solid-state imaging element and the distance d between the solid-state imaging element and the glass plate. Distance index r=(distance d between the solid-state imaging element and the glass plate) / (focal length f of the solid-state imaging element) Formula (2-1)

[0038] More specifically, one embodiment of a method for measuring the glare index value S of a glass plate 50 will be described with reference to Fig. 2. The measuring device 70C includes a sample to be measured, i.e., a glass plate 50, a detector 75 disposed on the first main surface 52 side of the glass plate 50, and a display device 54 with a resolution of 264 ppi disposed so as to contact the second main surface 53 of the glass plate 50. An LCD panel, for example, can be used as the display device 54. A green monochromatic image composed of RGB (0, 255, 0) is displayed on the display device 54, and the image viewed through the glass plate 50 is analyzed using a detector (analysis device) 75. The Sparkle value obtained from the image analysis results is used as the glare index S. ａ The glare S ａ The glare S was also measured under the same conditions for a glass substrate (VRD140 glass; manufactured by Asahi Glass Europe) having the same thickness as the glass plate 50 as a reference sample. ｓ The glare index value S of the glass plate is calculated from the values ​​of (a) and (b) by the above formula (2).

[0039] The solid-state imaging device used is the SMS-1000 manufactured by DM&S (Display-Messtechnik & Systeme), but if a successor device from DM&S that complies with JIS C1006: 2019 is available for this analysis device, that successor device may also be used. The camera lens may be, for example, a 23FM50SP lens (manufactured by Tamron Co., Ltd.).

[0040] As one of the optical properties of the glass plate according to this embodiment, the glare index value S at the outermost surface of the region having the uneven structure is 0.80 or more, preferably 0.81 or more, more preferably 0.82 or more, and the higher the value, the better, since this improves the visibility of the information displayed on the display. The upper limit of the glare index value S is 1.0. The glare index value S can be set to a desired range depending on, for example, the shape and density of the uneven structure.

[0041] <Reflection Image Diffusivity Index Value R> One index of the optical properties of the glass plate according to this embodiment is the reflection image diffuseness index value. The reflection image diffuseness index value indicates the degree to which the reflected image of an object (e.g., lighting) placed around the glass plate matches the original object. It has been confirmed that this index value correlates with the result of an observer's visual judgment of the anti-glare property, and exhibits behavior similar to human visual perception. For example, a glass plate having a small reflection image diffuseness index value R (close to 0) has poor anti-glare properties, while a glass plate having a large reflection image diffuseness index value R (closer to 1) has good anti-glare properties.

[0042] The reflected image diffuseness index value R is quantified by the following method. It is preferable to use the average value measured at three arbitrary points on a diagonal line as the reflected image diffuseness index value R in this specification. However, as the arbitrary measurement points, locations with extreme outliers are excluded. Using a DM&S SMS-1000, a 101 mm-wide slit-shaped light is emitted onto the glass plate from the first principal surface side, and the luminance of the reflected light is measured. A camera lens with a focal length of 16 mm and an aperture of 5.6 is used, the distance from the outermost surface of the first principal surface side of the glass plate to the camera lens is 300 mm, and the imaging scale is set in the range of 0.0276 to 0.0278. When the angle φ is set to 0° in the direction parallel to the thickness direction of the glass plate, light is emitted at an angle φ = 5.7° ± 0.1°, and the angle φ = -5.7° at the time of total reflection is used as the reference (angle α = 0°). The average brightness of the reflected light in the range of angle α = 0° ± 0.1° is R １ , the average brightness of the reflected light in the range of angle α = 0.5° ± 0.1° is R ２ , the average brightness of the reflected light in the range of angle α = −0.5° ± 0.1° is R ３ In this case, the value calculated by the following formula (5) is defined as the reflected image diffuseness index value R. ２ +R ３ ) / (2 x R １ ) Formula (5)

[0043] More specifically, one embodiment of a method for measuring the reflected image diffuseness index value R of a glass plate 50 will be described with reference to Fig. 3. The measurement device 70B has a light source 71 and a detector (analysis device) 75. A sample to be measured, i.e., a glass plate 50, is placed within the measurement device 70B with its first principal surface 52 facing the light source 71 and detector 75. A black plate 51 is placed on the second principal surface 53 side of the glass plate 50. The light source 71 emits a slit-shaped second light 731 having a width of 101 mm toward the glass plate 50. The detector (analysis device) 75 receives the reflected light reflected at a predetermined angle from the first principal surface 52 and analyzes its brightness.

[0044] During measurement, second light 731 is irradiated from light source 71 of measurement device 70B toward glass plate 50. When a direction parallel to the direction of normal L of glass plate 50 (thickness direction of the glass plate) is defined as angle φ=0°, second light 731 is irradiated onto glass plate 50 at an angle tilted by 5.7° clockwise (indicated by φ in FIG. 3 ). Note that, because actual measurements involve errors, angle φ more accurately includes a range of 5.7°±0.1°.

[0045] Next, the detector (analysis device) 75 is used to detect the specularly reflected light (hereinafter referred to as "first reflected light 733") among the light incident on the first main surface 52 of the glass plate 50, and the average brightness R １ In reality, the angle of the first reflected light 733 with respect to the normal line L is −(incident angle)°, so it is −5.7°±0.1° (α in FIG. 3). １ A minus (-) sign indicates that the angle is tilted counterclockwise relative to the normal L, and a plus (+) sign indicates that the angle is tilted clockwise relative to the normal.

[0046] Here, the first reflected light 733 is incident at an angle α=0°±0.1° (=α １ ) range.

[0047] Similarly, a second angle α is defined as an angle α=0.5°±0.1° with respect to a direction inclined by −5.7° from the first main surface 52 of the glass plate 50 relative to the normal line L (angle α=0°). ２The average value R of the brightness of the reflected light (hereinafter referred to as the "second reflected light 735") reflected by ２ , and a third angle α, represented by angle α=−0.5°±0.1°. ３ The average value R of the brightness of the reflected light (hereinafter referred to as the "third reflected light 737") reflected by ３ Measure.

[0048] The obtained luminance R １ , R ２ , R ３ The reflected image diffuseness index value R of the glass plate 50 is calculated using the above formula (5).

[0049] The analyzer used is the SMS-1000 manufactured by DM&S (Display-Messtechnik & Systeme), but if a successor device from DM&S conforming to JIS C1006:2019 is available for this analyzer, this successor device may also be used. Furthermore, the camera lens may be, for example, a C1614A lens (manufactured by Ricoh Co., Ltd.).

[0050] As one of the optical properties of the glass plate according to this embodiment, the reflected image diffusion index value R at the outermost surface of the region having the uneven structure is preferably 0.01 or more, more preferably 0.012 or more, and even more preferably 0.015 or more, from the viewpoint of being able to grasp information displayed on the display even in the presence of external light. On the other hand, from the viewpoint of preventing "whiteout," in which the entire surface becomes invisible due to scattered light when exposed to very strong external light, the reflected image diffusion index value R is preferably 0.95 or less, more preferably 0.8 or less, and even more preferably 0.6 or less. The reflected image diffusion index value R can be set to a desired range depending on, for example, the shape and density of the uneven structure.

[0051] <Lightness L ＊ Even if the glass plate satisfies the optical characteristics of the visibility index value T and the glare index value S, if the glass plate itself is whitish, visibility is affected. Therefore, the glass plate according to this embodiment has a lightness L measured by the specular elimination (SCE) method in accordance with the ASTM E313-73 standard. ＊ The lightness L ＊It is preferable to use the average value measured at three arbitrary points on the diagonal line, excluding points that give extremely outlier values.

[0052] The lightness L of the glass plate according to this embodiment ＊ If the value is 4.7 or less, the glass plate itself does not take on a whitish tint, and good visibility can be achieved. ＊ The value is 4.7 or less, preferably 4.5 or less, and more preferably 4.3 or less. The lower limit is not particularly limited, but is usually 0.01 or more.

[0053] Lightness L in this embodiment ＊ The values ​​are measured by the specular reflection excluded (SCE) method in accordance with the ASTM E313-73 standard, which measures only diffuse reflected light by eliminating specular reflected light. ＊ Therefore, the L measured by the SCE method is in good agreement. ＊ a ＊ b ＊ Lightness L in the color system ＊ The value can be regarded as an index of the whiteness of the glass plate.

[0054] The lightness L of the glass plate according to this embodiment ＊ The value can be reduced by reducing the transmission haze value of the glass plate. It has also been newly discovered that the value can be reduced by forming a specific absorptive antireflection film so as to cover the uneven structure provided on the first principal surface side.

[0055] First and Second Embodiments The first main surface of the glass plate according to this embodiment has an uneven structure on at least a part thereof. This uneven structure performs an anti-glare (AG) function, imparting anti-glare properties to the glass plate.

[0056] As a result of investigations by the present inventors, it has been found that the following first and second embodiments can be given as examples of the glass plate according to this embodiment.

[0057] First Embodiment In the first embodiment, the first main surface of the glass plate further has an anti-reflection coating on at least a portion thereof, and the anti-reflection coating covers at least a portion of the concave-convex structure. Here, the glass plate has a luminous transmittance of 20 to 85% measured at the outermost surface on the first main surface side of the region having the anti-reflection coating, and a luminous transmittance of 20 to 85% measured at the outermost surface on the first main surface side of the region having the anti-reflection coating in a transmitted color under a D65 light source measured in accordance with JIS Z 8729 (2004) for the same region. ＊ The luminous reflectance measured on the outermost surface on the first principal surface side of the region having the antireflection film covering the concave-convex structure of the glass plate is 1% or less, and the sheet resistance of the antireflection film is 10 ４ Ω / □ or more.

[0058] Anti-reflection film In the first embodiment, the anti-reflection film may cover at least a part of the concave-convex structure, and it is preferable that the anti-reflection film covers the areas of the glass plate that are visible and that are touched for swiping actions, etc. When the concave-convex structure is formed in all of the areas that are visible and that are touched, it is preferable that the anti-reflection film is formed in all of those areas.

[0059] Generally, providing an anti-reflection film on a glass plate reduces the reflectance, thereby reducing the glare caused by the reflection of light. Furthermore, when a glass plate having an anti-reflection film is used in a display device, the transmittance of light from the display device can be improved, thereby improving the visibility of the image display device. In addition, in this embodiment, by providing an absorptive anti-reflection film as described below, the lightness L of the glass plate can be improved even when the transmission haze as described below is high. ＊ It was found that the values ​​could be reduced. The effect of providing an anti-reflection film on the visibility index value T and the glare index value S is extremely small. Therefore, even when an anti-reflection film is formed, the visibility index value T and the glare index value S on the outermost surface of the region having the uneven structure of the glass plate after the anti-reflection film is formed can be considered to be the same as the visibility index value T and the glare index value S, respectively, before the anti-reflection film is formed.

[0060] The absorptive antireflection film has a laminated structure in which two or more dielectric layers with different refractive indices are alternately stacked. By stacking the dielectric layers with different refractive indices, light reflection can be suppressed. The absorptive antireflection film may be stacked in the order of a high refractive index layer and a low refractive index layer, or a low refractive index layer and a high refractive index layer, from the side closer to the first main surface of the glass plate. Furthermore, when the number of layers is three or more, it is not necessary for all layers to have different refractive indices.

[0061] For example, in the case of a three-layer laminate structure, the layers may be arranged in the order from the side closest to the first main surface of the glass plate as a low refractive index layer, a high refractive index layer, and a low refractive index layer, or as a high refractive index layer, a low refractive index layer, and a high refractive index layer. In the former case, the two low refractive index layers may have the same refractive index, and in the latter case, the two high refractive index layers may have the same refractive index. The same applies when the number of layers is four or more. In this specification, a high refractive index layer is, for example, a layer having a refractive index of 1.9 or more at a wavelength of 550 nm, and a low refractive index layer is a layer having a refractive index of 1.6 or less at a wavelength of 550 nm. Alternatively, the structure may include a layer having a refractive index of 1.2 to 1.4 at a wavelength of 550 nm, in which hollow particles or pores are mixed in the matrix of the layer.

[0062] In a preferred embodiment of the absorptive antireflection film, fine particles having light absorbing ability may be dispersed in the dielectric layer. As the fine particles having light absorbing ability, those having high light absorbing ability over the entire wavelength range of visible light are used. In this embodiment, by using fine particles having high light absorbing ability over the entire wavelength range of visible light as the fine particles dispersed in the dielectric layer, it is possible to more effectively prevent the transmitted light from becoming yellowish.

[0063] Specifically, the fine particles are preferably at least one selected from the group consisting of Ag, Mo, W, Cu, Au, Pd, Pt, Ir, Ni, Co, Fe, Cr, C, TiC, SiC, TiN, and CrN. All of the fine particles in the above group have high redox potentials, making them less likely to react with surrounding oxides to form oxide fine particles. Furthermore, they have high light absorption capabilities, so even a small amount of fine particles can provide sufficient light absorption, reducing the risk of the fine particles sticking together and causing macroscopic conductivity. They also have the advantage of being relatively easy to obtain. Therefore, at least one fine particle selected from the above group is preferred. The fine particles dispersed in the dielectric layer may be one or more of the above types. Although the fine particle options listed above are highly conductive, the absorptive antireflection coating is insulating because they are dispersed as fine particles in the dielectric layer.

[0064] The fine particles may be dispersed in the high refractive index layer, the low refractive index layer, or both. The number of dielectric layers in which the fine particles are dispersed is not particularly limited, and may be one layer or two or more layers.

[0065] It is preferable that fine particles are dispersed in a dielectric layer other than the outermost layer among the dielectric layers constituting the absorptive antireflection coating. Note that it is the dielectric layer in which the fine particles are dispersed that affects the luminous transmittance and luminous reflectance measured at the outermost surface of the glass plate according to this embodiment, as well as the sheet resistance of the absorptive antireflection coating.

[0066] The dielectric layer is preferably composed mainly of at least one oxide selected from the group consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, or at least one nitride selected from the group consisting of Si and Al, and from the viewpoints of productivity and refractive index, it is more preferable that the high refractive index layer is composed of one selected from niobium oxide, tantalum oxide, and silicon nitride, and the low refractive index layer is composed of a layer made of silicon oxide, for the reasons described below.

[0067] It is preferable that the dielectric layer itself does not have light absorption ability, and therefore, a layer with low absorption ability across the entire visible wavelength range is preferred. Furthermore, to obtain a film with anti-reflection properties, a low refractive index layer preferably has a refractive index of 1.5 or less at a wavelength of 550 nm, and a high refractive index layer preferably has a refractive index of 1.8 or more. Selection from the above group satisfies these conditions. In this specification, "mainly" means that the ratio of the above oxide or nitride to the constituent materials of the dielectric layer is 70% by mass or more.

[0068] The constituent materials of the dielectric layers are appropriately selected from the oxides or nitrides described above so that they each become the desired refractive index layer (high refractive index layer, low refractive index layer). Note that the constituent materials of the dielectric layers are appropriately selected so that they become the desired refractive index layer (high refractive index layer, low refractive index layer) including the refractive index due to the fine particles. Note that the dielectric layers may be composed of only one type of the oxides or nitrides described above, or may be composed of two or more types.

[0069] In light of the above, a preferred specific example of an absorptive antireflection coating is one in which the main component of each dielectric layer in the laminate structure is at least one oxide selected from the group consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, or at least one nitride of Si and Al, and at least one of the dielectric layers has dispersed therein at least one fine particle selected from the group consisting of Ag, Mo, W, Cu, Au, Pd, Pt, Ir, Ni, Co, Fe, Cr, C, TiC, SiC, TiN, and CrN.

[0070] In another preferred embodiment of the absorptive antireflection coating, one of the layers constituting the laminate structure is composed of a mixed oxide of at least one element selected from Group A consisting of Mo and W and at least one element selected from Group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In. However, the content of the elements of Group B contained in the mixed oxide relative to the total of the elements of Group A contained in the mixed oxide and the elements of Group B contained in the mixed oxide (hereinafter referred to as the Group B content) is preferably less than 50 mass%. The other layer constituting the laminate structure is composed of an oxide whose main component is Si, i.e., SiO ２It is composed of:

[0071] Half-tone masks used in the semiconductor manufacturing field are known as light-transmitting films that have the ability to absorb light and are insulating. Half-tone masks include Mo-SiO ｘ An oxygen-deficient film such as a film is used. As an optically insulating and light-transmitting film having light absorption ability, there is a narrow band gap film used in the field of semiconductor manufacturing.

[0072] However, these films have a high ability to absorb light at short wavelengths in the visible light spectrum, which causes the transmitted light to have a yellowish tint, making them unsuitable for use as cover glasses for image display devices.

[0073] In this embodiment, a layer having a high Mo content and a layer having a SiO ２ By forming a laminated structure with a layer composed of the above, a glass plate can be obtained that has light absorption ability, is insulating, and does not yellow transmitted light. Note that, in this specification, the term "main component" refers to a layer in which the ratio of a mixed oxide of at least one selected from Group A consisting of Mo and W and at least one selected from Group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In in the layer constituent materials is 70 mass% or more, and refers to a layer in which the ratio of Si oxide in the layer constituent materials is 70 mass% or more.

[0074] The layer whose main component is a mixed oxide of group A and group B is called layer (A-B-O), and the layer whose main component is an oxide of Si is called layer (SiO ２ ) in the transmitted color of the glass plate under the D65 light source, ＊ From the viewpoint of lowering the value, the content of group B in the layer (ABO) is preferably less than 50% by mass, more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less.

[0075] The absorptive antireflection film is a layer (SiO ２ ), and layer (A-B-O), the layer (A-B-O) and layer (SiO ２) may be laminated in this order. Alternatively, a laminate structure may be used in which three or more layers having different refractive indices are laminated. In this case, at least one layer is a layer (SiO ２ ), and at least one other layer is required to be layer (A-B-O), and other layers may or may not be included. ２ ), and when there are a plurality of layers (A-B-O), those layers (SiO ２ The layers (A-B-O) may be the same or different from each other. The same applies when the number of layers is four or more.

[0076] The outermost layer of the absorptive anti-reflection film is a layer (SiO ２ ) is preferable because the outermost layer is a layer (SiO ２ ) can be produced relatively easily. In addition, when an antifouling film is further formed, a layer (SiO ２ For this reason, it is preferable that the outermost layer of the absorptive antireflection film is formed on the layer (SiO ２ ) is preferred.

[0077] In any embodiment of the absorptive antireflection film, from the viewpoint of preventing reflection of external light on the glass plate, the luminous reflectance measured on the outermost surface on the first principal surface side of the region where the absorptive antireflection film covering the uneven structure is formed is preferably 1% or less, more preferably 0.8% or less, and even more preferably 0.6% or less. The lower limit of the luminous reflectance is not particularly limited, but is usually 0.1% or more. The luminous reflectance in this specification is a value measured in accordance with JIS Z 8701 (1999). It is preferable to use the average value measured at three arbitrary points on a diagonal line as the luminous reflectance. However, the arbitrary measurement points should exclude points with extreme outliers.

[0078] In any of the above-described embodiments of the absorptive antireflection film, when a touch panel is attached to a glass plate, the sheet resistance of the absorptive antireflection film is set to 10 or less from the viewpoint of maintaining the change in capacitance due to finger contact required for a capacitive touch sensor and ensuring that the touch panel functions properly. ６ Ω / □ or more is preferable, and 10 ７Ω / □ or more is more preferable, and 10 ８ The upper limit of the sheet resistance of the absorptive antireflection film is not particularly limited, but is usually 10 １０ Ω / □ or less. The sheet resistance of the absorptive antireflection coating in this specification is a value measured in accordance with ASTM D257 or JIS K 6271-6 (2008). It is preferable to use an average value measured at three arbitrary points on a diagonal line as the sheet resistance of the antireflection coating in this specification. However, points where extreme outliers are obtained are excluded from the arbitrary measurement points.

[0079] The sheet resistance of the absorptive antireflection film, the luminous reflectance and the luminous transmittance measured on the outermost surface on the first main surface side of the region where the absorptive antireflection film is formed, and the b ＊ To achieve a value within a desired range, it is preferable to select an appropriate combination of the dielectric layer in the absorptive antireflection coating and the fine particles dispersed in the dielectric layer.

[0080] The dielectric layer in which the particles are dispersed has a sheet resistance of 10 ８ Ω / □ or more is preferable, and 10 ９ On the other hand, the volume resistivity of the fine particles as a single substance is preferably 10 －５ It is preferably Ωm or less.

[0081] The dielectric layer in which the fine particles are dispersed preferably has an extinction coefficient at a wavelength of 550 nm in the range of 0.005 to 3, more preferably 0.01 to 1. From the viewpoint of obtaining good absorption characteristics with a reasonable film thickness and realizing a suitable luminous transmittance, the extinction coefficient is preferably 0.005 or more, more preferably 0.01 or more. On the other hand, from the viewpoint of preventing excessively strong absorption and a low luminous transmittance, the extinction coefficient is preferably 3 or less, more preferably 1 or less. This prevents the transmitted light from becoming yellowish, and the b of the glass plate ＊ The value can also be set within a suitable range.

[0082] Furthermore, the dielectric layer formed on the dielectric layer in which the fine particles are dispersed preferably has a dielectric constant of 1.3 to 1.5 and a thickness of 30 to 150 nm.

[0083] The luminous transmittance, b ＊ Examples of glass plates having a value, luminous reflectance, and sheet resistance that satisfy the preferred ranges include the following: a glass plate having an absorptive antireflection film formed on one main surface thereof, and a dielectric layer having dispersed therein fine particles having light absorption ability formed on the other main surface thereof.

[0084] Examples of fine particles capable of absorbing light include oxides such as chromium oxide and iron oxide, carbides such as chromium carbide and tungsten carbide, carbon black, and mica.

[0085] Examples of the dielectric layer in which the fine particles having light absorbing ability are dispersed include resin layers made of homopolymers such as epoxy resins, acrylic resins, polyethylene terephthalate, polyethersulfone, polyarylate, polycarbonate, transparent ABS resins, phenolic resins, acrylonitrile-butadiene-styrene resins, polyurethane, polymethyl methacrylate, polyvinyl, polyvinyl butyral, polyether ether ketone, polyethylene, polyester, polypropylene, polyamide, and polyimide, as well as copolymers of monomers of these resins with monomers copolymerizable therewith.

[0086] ...Luminous transmittance of glass plate In the first embodiment, the luminous transmittance measured on the outermost surface on the first main surface side of the region having the antireflection film is preferably 20 to 85%. Here, from the viewpoint of having a moderate light absorption ability and suppressing reflection from the interface between the display device and the adhesive layer when the glass plate is used as a cover glass for a display device, thereby improving the bright contrast of the display device, the luminous transmittance is preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, and preferably 85% or less, more preferably 80% or less, and even more preferably 75% or less. The luminous transmittance in this specification is a value measured in accordance with JIS Z 8701 (1999). Furthermore, the luminous transmittance in this specification is preferably an average value measured at three arbitrary points on a diagonal line. However, extreme outliers are excluded from the arbitrary measurement points.

[0087] Glass plate b＊ Value b measured in the area of ​​the glass plate in the first embodiment having the anti-reflection film ＊ From the viewpoint of preventing transmitted light from becoming yellowish and enabling the glass to be suitably used as a cover glass for a display device, the value is preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less. ＊ The lower limit of the value is not particularly limited, and may be 0. ＊ The value is a value of transmitted color under a D65 light source measured in accordance with JIS Z 8729 (2004). ＊ It is preferable to use the average value measured at three arbitrary points on the diagonal line, excluding points that give extremely outlier values.

[0088] Transmission Haze Generally, the transmission haze measured at the outermost surface of the region on the first main surface side of the glass plate, which has the uneven structure and the non-absorptive antireflection film, increases as the value increases, and the glass plate appears whiter. Therefore, regarding the whiteness of the glass plate, the lightness L of the glass plate according to the SCE method is used. ＊ However, the inventors' investigations have revealed that when the absorptive antireflection film is formed so as to cover the uneven structure, the lightness L of the glass plate measured by the SCE method is not significantly different from that of the conventional antireflection film, even if the transmission haze is 15% or more. ＊ It was found that the value could be reduced to 4.7 or less, and the whiteness of the glass plate could be suppressed.

[0089] Therefore, the transmission haze in the first embodiment may be 15% or more, 17% or more, or 20% or more. ＊From the viewpoint of reducing the value, the transmission haze is preferably 35% or less, more preferably 32% or less, and even more preferably 30% or less. In this specification, the transmission haze represents the transmittance loss caused by surface reflection (Fresnel reflection) due to the difference in refractive index between the glass plate and air when light is incident on the glass plate, and is measured by a method conforming to JIS K 7136 (2000). In this specification, the transmission haze is preferably an average value measured at three arbitrary points on a diagonal line. However, as the arbitrary measurement points, points with extreme outliers are excluded.

[0090] Specifically, the transmission haze is quantified by the following method. Using a haze meter HZ-1 manufactured by Suga Test Instruments Co., Ltd., a glass plate is placed on a light source with the first main surface of the glass plate facing the light source, and the transmitted light is measured from above the glass plate. When the direction parallel to the thickness direction of the glass plate is defined as an angle of 0°, light detected within ±2.5° is defined as transmitted light, and light detected at an angle less than -2.5° or more than +2.5° is defined as scattered light (transmitted light loss). The sum of the transmitted light and scattered light, i.e., the proportion of the scattered light relative to the total light transmission, is defined as the transmission haze (%).

[0091] ...Uneven Structure-1 In the first embodiment, one aspect of the uneven structure on the first principal surface of the glass plate is at least partially covered with an absorbing anti-reflection film. The surface of the uneven structure preferably satisfies one or more of the following (1) to (4) with respect to surface roughness, more preferably two or more, even more preferably three or more, and particularly preferably all four. Furthermore, when an absorbing anti-reflection film, anti-fouling film, or the like is formed to cover the uneven structure, the outermost surface after the film formation preferably satisfies one or more of the following (1) to (4), more preferably two or more, even more preferably three or more, and particularly preferably all four. Note that the absorbing anti-reflection film, etc., is formed following the formed uneven structure, so the formed uneven structure and the uneven shape of the outermost surface on which the absorbing anti-reflection film, etc., is formed are substantially identical. (1) The element mean length Rsm of the roughness curve is less than 26 μm. (2) The arithmetic mean roughness Ra is 0.12 μm or more. (3) The skewness Rsk is −1 to 1. (4) The kurtosis Rku is 2 to 4.

[0092] The element mean length Rsm of the roughness curve means the average length of the profile curve elements in the reference length, and is a value measured in accordance with JIS B 0601 (2013) (ISO 4287:1997). The element mean length Rsm of the roughness curve is preferably less than 26 μm, and from the viewpoint of reducing light interference caused by the uneven structure and increasing the glare index value S, it is more preferably 24 μm or less, and even more preferably 22 μm or less. On the other hand, from the viewpoint of increasing the reflected image diffusion index value R, the element mean length Rsm of the roughness curve is preferably 5 μm or more, more preferably 7 μm or more, and even more preferably 9 μm or more.

[0093] The arithmetic mean roughness Ra means the average of the absolute values ​​of Z(x) over a reference length, and is a value measured in accordance with JIS B 0601 (2013) (ISO 4287:1997). From the viewpoint of increasing the reflected image diffusion index value R, the arithmetic mean roughness Ra is preferably 0.12 μm or more, more preferably 0.13 μm or more, and even more preferably 0.14 μm or more. On the other hand, from the viewpoint of ensuring the stability of the uneven structure, the arithmetic mean roughness Ra is preferably 0.3 μm or less, more preferably 0.28 μm or less, and even more preferably 0.26 μm or less.

[0094] The skewness Rsk is the cube mean of Z(x) at a reference length that has been made dimensionless by the cube of the root mean square height (Zq), and is a value measured in accordance with JIS B 0601 (2013). The skewness Rsk is preferably -1 to 1. Here, from the viewpoint of defining the structure of the tip end of the uneven structure and reducing dynamic friction resistance, the skewness Rsk is preferably -1 or more, more preferably -0.9 or more, even more preferably -0.8 or more, and preferably 1 or less, more preferably 0.9 or less, and even more preferably 0.8 or less.

[0095] Kurtosis Rku is the fourth-squared mean of Z(x) at a reference length that has been made dimensionless by the fourth power of the root mean square height (Zq), and is a value measured in accordance with JIS B 0601 (2013). Kurtosis Rku is preferably 2 to 4. Here, from the viewpoint of defining the sharpness of the tip of the uneven structure and reducing dynamic friction resistance, kurtosis Rku is preferably 2 or more, more preferably 2.2 or more, even more preferably 2.4 or more, and preferably 4 or less, more preferably 3.8 or less, and even more preferably 3.6 or less. In this specification, the element mean length Rsm, arithmetic mean roughness Ra, skewness Rsk, and kurtosis Rku of the roughness curve are preferably average values ​​measured at any three points on the diagonal. However, points with extreme outliers are excluded from the arbitrary measurement points.

[0096] The glass plate having the above-described uneven structure in this embodiment can be obtained by, for example, a frosting method, the details of which will be described later.

[0097] Furthermore, in the first embodiment having the above-mentioned uneven structure-1, the arithmetic mean roughness Ra is relatively large, and the element mean length Rsm of the roughness curve, i.e., the width of the unevenness, is relatively small. Furthermore, the skewness Rsk and kurtosis Rku are close to a normal distribution. That is, the cracks in the first embodiment are not deep, so in order to achieve the desired average dynamic friction coefficient COF and friction change amount delta and to achieve a good tactile feel when swiping while maintaining the visibility index value T and glare index value S at a certain value or higher, the tips of the unevenness must be sharp. Therefore, the transmission haze tends to be high.

[0098] However, the inventors have found that by covering at least a part of the uneven structure with the absorptive anti-reflection film, the whiteness of the substrate can be suppressed even if the transmission haze is high, and the brightness L in the SCE method can be reduced. ＊ It was found that the value could be reduced to 4.7 or less.

[0099] ...Uneven Structure-2 In the first embodiment, at least a portion of the uneven structure on the first principal surface of the glass plate is covered with an absorptive anti-reflection film. The surface of the uneven structure preferably satisfies one or more of the following conditions (1) to (3) with respect to surface roughness, more preferably two or more, and particularly preferably all three. Furthermore, when an absorptive anti-reflection film, anti-fouling film, or the like is formed to cover the uneven structure, the outermost surface after the film formation preferably satisfies one or more of the following conditions (1) to (3), more preferably two or more, and even more preferably all three. Since the absorptive anti-reflection film or the like is formed following the formed uneven structure, the formed uneven structure and the uneven shape of the outermost surface on which the absorptive anti-reflection film or the like is formed are substantially identical. (1) The element mean length Rsm of the roughness curve is 26 μm or more. (2) The skewness Rsk is -4 to -1.5. (3) Kurtosis Rku is 5 to 20.

[0100] The element mean length Rsm of the roughness curve is preferably 26 μm or more, more preferably 27 μm or more, even more preferably 28 μm or more, even more preferably 30 μm or more, and most preferably 32 μm or more. On the other hand, from the viewpoint of preventing a touching finger from touching recesses, the element mean length Rsm of the roughness curve is preferably 50 μm or less, more preferably 48 μm or less, and even more preferably 46 μm or less.

[0101] The skewness Rsk is preferably −4 to −1.5. Here, from the viewpoint of defining the structure of the tip end of the uneven structure and reducing dynamic friction resistance, the skewness Rsk is preferably −4 or more, more preferably −3.8 or more, even more preferably −3.6 or more, and is preferably −1.5 or less, more preferably −1.7 or less, even more preferably −1.9 or less, and even more preferably −2.5 or less.

[0102] The kurtosis Rku is preferably 5 to 20. Here, from the viewpoint of defining the sharpness of the tip of the uneven structure and reducing dynamic friction resistance, the kurtosis Rku is preferably 5 or more, more preferably 6 or more, even more preferably 7 or more, even more preferably 11 or more, and is preferably 20 or less, more preferably 18 or less, and even more preferably 16 or less.

[0103] The shape of the concave-convex structure may further be considered in terms of arithmetic mean roughness Ra. The arithmetic mean roughness Ra is preferably 0.01 μm or more, more preferably 0.02 μm or more, and even more preferably 0.03 μm or more. On the other hand, from the viewpoint of ensuring the stability of the concave-convex structure, the arithmetic mean roughness Ra is preferably 0.30 μm or less, more preferably 0.28 μm or less, and even more preferably 0.26 μm or less.

[0104] The glass plate satisfying the uneven structure-2 in this embodiment can be obtained, for example, by employing a wet blasting method, the details of which will be described later.

[0105] In the first embodiment, the aspect having the above-mentioned uneven structure-2 has a relatively large element mean length Rsm of the roughness curve, i.e., the width of the unevenness. Furthermore, the skewness Rsk is large in the negative direction, i.e., the tips of the concave portions, which are valleys, are sharp, and the tips of the convex portions, which are mountains, are rounded. Furthermore, the kurtosis Rku is relatively large, and the symmetry of the shapes of the concave portions and convex portions deviates from the normal distribution, with the tips of the convex portions being rounded.

[0106] By adopting such an embodiment, it is possible to maintain the visibility index value T and the glare index value S at a certain value or higher, while realizing the desired average dynamic friction coefficient COF and friction change amount delta, improving the tactile feel when swiping, and easily maintaining a low transmission haze. However, depending on the desired optical properties and tactile feel, the transmission haze may be 15% or more. Even in this case, by covering at least a portion of the uneven structure with the absorptive anti-reflection film, it is possible to suppress the whiteness of the substrate, and the brightness L in the SCE method can be improved. ＊ The value can be 4.7 or less.

[0107] Second Embodiment In a second embodiment, the outermost surface of the region having the uneven structure on the first main surface side of the glass plate has a transmission haze of less than 15% as measured by a method in accordance with JIS K 7136 (2000).

[0108] Transmission Haze: The transmission haze measured at the outermost surface of the region having the uneven structure and, optionally, the anti-reflection film on the first main surface side of the glass plate indicates that the larger the value, the more light is scattered, and the whiter the glass plate appears. Therefore, regarding the whiteness of the glass plate, the lightness L of the glass plate according to the SCE method is used. ＊ From the viewpoint of reducing the value, the transmission haze is preferably less than 15%, more preferably 14% or less, and even more preferably 13% or less. The upper limit of the transmission haze is not particularly limited, but is usually 0.1% or more.

[0109] ...Uneven Structure In the second embodiment, the surface of the uneven structure on the first main surface side of the glass plate preferably satisfies one or more of the following (1) to (3) with respect to surface roughness, more preferably satisfies two or more, and even more preferably satisfies all three. As described above, the uneven structure may optionally further include an anti-reflection film or an anti-fouling film on at least a portion thereof. However, if these films are formed, the outermost surface after film formation preferably satisfies one or more of the following (1) to (3), more preferably satisfies two or more, and even more preferably satisfies all three. Note that, since the anti-reflection film or the like is formed following the formed uneven structure, the formed uneven structure and the uneven shape of the outermost surface on which the anti-reflection film or the like is formed are substantially identical. (1) The element mean length Rsm of the roughness curve is 26 μm or more. (2) The skewness Rsk is -4 to -1.5. (3) The kurtosis Rku is 5 to 20.

[0110] The element mean length Rsm of the roughness curve means the average length of the profile curve element in the reference length, and is a value measured in accordance with JIS B 0601 (2013). The element mean length Rsm of the roughness curve is preferably 26 μm or more, more preferably 27 μm or more, even more preferably 28 μm or more, even more preferably 30 μm or more, and most preferably 32 μm or more. On the other hand, from the viewpoint of preventing a touching finger from touching recesses, the element mean length Rsm of the roughness curve is preferably 50 μm or less, more preferably 48 μm or less, and even more preferably 46 μm or less.

[0111] The skewness Rsk is the cube mean of Z(x) at a reference length that has been made dimensionless by the cube of the root mean square height (Zq), and is a value measured in accordance with JIS B 0601 (2013). The skewness Rsk is preferably -4 to -1.5. Here, from the viewpoint of defining the structure of the tip of the uneven structure and reducing dynamic friction resistance, the skewness Rsk is preferably -4 or more, more preferably -3.8 or more, even more preferably -3.6 or more, and preferably -1.5 or less, more preferably -1.7 or less, even more preferably -1.9 or less, and even more preferably -2.5 or less.

[0112] Kurtosis Rku is the fourth-mean value of Z(x) at a reference length that has been made dimensionless by the fourth power of the root mean square height (Zq), and is a value measured in accordance with JIS B 0601 (2013). Kurtosis Rku is preferably 5 to 20. Here, from the viewpoint of defining the sharpness of the tip of the uneven structure and reducing dynamic friction resistance, kurtosis Rku is preferably 5 or more, more preferably 6 or more, even more preferably 7 or more, even more preferably 11 or more, and preferably 20 or less, more preferably 18 or less, and even more preferably 16 or less.

[0113] The shape of the uneven structure may further be considered in terms of arithmetic mean roughness Ra. This refers to the average absolute value of Z(x) over a reference length, and is a value measured in accordance with JIS B 0601 (2013). The arithmetic mean roughness Ra is preferably 0.01 μm or more, more preferably 0.02 μm or more, and even more preferably 0.03 μm or more. On the other hand, from the viewpoint of ensuring the stability of the uneven structure, the arithmetic mean roughness Ra is preferably 0.30 μm or less, more preferably 0.28 μm or less, and even more preferably 0.26 μm or less.

[0114] The glass plate according to the second embodiment can be obtained by, for example, employing a wet blasting method and setting the spray angle of the slurry within an appropriate range, as will be described in detail later.

[0115] In addition, in the second embodiment, the element mean length Rsm of the roughness curve, i.e., the width of the unevenness, is relatively large. Also, the skewness Rsk is large in the negative direction, i.e., the tips of the concave portions that become valleys are sharp, and the tips of the convex portions that become mountains are rounded. Furthermore, the kurtosis Rku is relatively large, the symmetry of the shapes of the concave portions and convex portions deviates from the normal distribution, and the tips of the convex portions are rounded. Thus, in the second embodiment, by deepening the cracks, i.e., deepening the concave portions and convex portions, it is possible to achieve the desired average dynamic friction coefficient COF and friction change amount delta while maintaining low transmission haze. As a result, the whiteness of the substrate can be suppressed, and the lightness L in the SCE method can be improved. ＊ It was found that the values ​​could be kept low.

[0116] In the second embodiment, the antireflection film is optional. For example, if an antireflection film similar to the absorption type antireflection film in the first embodiment is formed so as to cover at least a part of the uneven structure, the whiteness of the substrate can be suppressed and the brightness L can be improved, as in the first embodiment. ＊ In this case, the preferred embodiment of the antireflection film is the same as the preferred embodiment of the absorptive antireflection film in the first embodiment.

[0117] In addition to the above, in the second embodiment, since the transmission haze is less than 15%, the antireflection film of the first embodiment can be employed, and other antireflection films that have been widely used in the past may also be employed. For example, in an antireflection film having a laminate structure in which two or more low-refractive-index layers and two or more high-refractive-index layers are alternately laminated, the main component of the high-refractive-index layer is preferably at least one selected from the group consisting of silicon nitride, titanium oxide, niobium oxide, tantalum oxide, and zirconium oxide.

[0118] The greater the number of layers in the laminated structure, the lower the reflectivity can be achieved over a wider wavelength range. For example, the total number of layers in the laminated structure of the antireflection film is preferably 2 to 8, and more preferably 2 to 6, from the viewpoints of reflectance reduction effect and mass productivity.

[0119] The materials for the high refractive index layer and the low refractive index layer are not particularly limited and can be appropriately selected in consideration of the required level of antireflection property, productivity, and the like. However, the main component of the high refractive index layer is preferably, for example, at least one selected from the group consisting of silicon nitride, titanium oxide, niobium oxide, tantalum oxide, and zirconium oxide, as described above, and from the viewpoints of productivity and refractive index, at least one selected from the group consisting of silicon nitride, niobium oxide, and tantalum oxide is more preferred.

[0120] The material constituting the low refractive index layer is preferably at least one selected from the group consisting of silicon oxide, a material containing a mixed oxide of Si and Sn, a material containing a mixed oxide of Si and Zr, and a material containing a mixed oxide of Si and Al, and from the viewpoints of productivity and refractive index, a layer made of silicon oxide is more preferred.

[0121] Furthermore, the preferred ranges of the luminous reflectance measured on the outermost surface on the first main surface side of the region having the antireflection film and the sheet resistance of the antireflection film are also the same as the preferred ranges of the luminous reflectance and sheet resistance in the first embodiment, respectively.

[0122] ..Luminous transmittance of glass plate, b ＊ Value: Luminous transmittance and b measured on the outermost surface on the first principal surface side of the glass plate according to the second embodiment ＊ The preferred range of the value is the luminous transmittance and b measured on the outermost surface on the first main surface side of the glass plate according to the first embodiment. ＊ The preferred ranges of values ​​are the same as those of the respective values.

[0123] <Composition of Glass Plate> In the glass plate according to this embodiment, the mother glass preferably has a refractive index of 1.4 to 1.7, from the viewpoint of sufficiently suppressing reflection at the bonding surface when optically bonding a display, a touch panel, or the like.

[0124] Specifically, glass of various compositions can be used, including, for example, alkali-free glass, soda-lime glass, soda-lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, lead glass, alkali-barium glass, aluminoborosilicate glass, and borosilicate glass. Among these, soda-lime glass and aluminosilicate glass are more preferred from the viewpoint of facilitating ion exchange in the chemical strengthening treatment described below. Furthermore, the glass composition preferably contains sodium, and is preferably a composition that can be strengthened by molding and chemical strengthening treatment.

[0125] More specifically, the glass composition is expressed in mole percent based on oxides, for example, SiO ２ 50 to 80%, Al ２ O ３ 0.1 to 25%, Li ２ O + Na ２ O+K ２ O 3 to 30%, MgO 0 to 25%, CaO 0 to 25% and ZrO ２ However, there is no particular limitation thereto.

[0126] More specifically, the following glass compositions (i) to (v) can be mentioned: For example, "containing 0 to 25% MgO" means that MgO is not essential but may be contained in an amount up to 25%.

[0127] (i) Composition expressed in mole percent on an oxide basis, the composition expressed in mole percent is SiO ２ 63 to 73%, Al ２ O ３ 0.1 to 5.2%, Na ２ O 10-16%, K ２ 0 to 1.5% O, Li ２ (ii) a glass containing 0 to 5.0% of O, 5 to 13% of MgO, and 4 to 10% of CaO, and (iii) a glass having a composition expressed in mole percent based on oxides of SiO ２ 50 to 74%, Al ２ O ３ 1-10%, Na ２ O 6-14%, K ２ 3-11% O, Li ２ O 0 to 5.0%, MgO 2 to 15%, CaO 0 to 6% and ZrO ２ Contains 0 to 5% of SiO ２ and Al ２ O ３ The total content of is 75% or less, Na ２ O and K ２ (iii) a glass having a composition expressed in mole percent on an oxide basis of SiO ２ 68 to 80%, Al ２ O ３ 4-10%, Na ２ O 5-15%, K ２ O 0-1%, Li ２ O 0 to 5.0%, MgO 4 to 15% and ZrO ２ (iv) a glass containing 0 to 1% of SiO ２ 67 to 75%, Al ２ O ３ 0-4%, Na ２ O 7-15%, K ２ O 1 to 9%, Li ２ O 0 to 5.0%, MgO 6 to 14% and ZrO２ Contains 0 to 1.5% of SiO ２ and Al ２ O ３ The total content of 71-75%, Na ２ O and K ２ (v) a glass having a composition expressed in mole percent on an oxide basis of SiO ２ 56 to 73%, Al ２ O ３ 7 to 24%, B ２ O ３ 0 to 6%, P ２ O ５ 0 to 6%, Li ２ 2-12% O, Na ２ O 2-11%, K ２ O 0-5%, MgO 0-8%, CaO 0-2%, SrO 0-5%, BaO 0-5%, ZnO 0-5%, TiO ２ 0 to 2% and ZrO ２ (vi) A glass containing 0 to 4% of SiO ２ 58 to 80%, Al ２ O ３ 13-18%, B ２ O ３ 0 to 5%, P ２ O ５ 0.5-4%, Li ２ 3-10% O, Na ２ O 5-20%, K ２ O 0-2%, MgO 0-11%, CaO 0-20%, SrO 0-20%, BaO 0-15%, ZnO 0-10%, TiO ２ 0 to 1%, ZrO ２ Glass containing 0 to 2% of

[0128] <Chemical Strengthening Treatment> In order to increase the strength of the glass plate according to the present embodiment and prevent breakage when external stress is applied, it is preferable to introduce a compressive stress layer on the outermost surface of the glass plate, and it is more preferable to make the glass plate a chemically strengthened glass plate that has been subjected to chemical strengthening treatment by ion exchange treatment.

[0129] When chemical strengthening treatment is performed on a glass plate, in order to perform the chemical strengthening treatment appropriately, Li in the glass composition ２ O and Na ２ The total content of O is preferably 12 mol % or more. Furthermore, in order to increase the surface compressive stress (CS) and the depth of the compressive stress layer (DOL), the glass composition of the glass plate is preferably SiO ２ 60 mol % or more of Al ２ O ３ It is preferable that the content is 8 mol % or more.

[0130] <Anti-fouling film> The glass plate according to this embodiment may further have an anti-fouling (AFP: Anti Finger Print) film so as to cover the uneven structure formed on the first main surface or on the anti-reflection film. The anti-fouling film is a film that suppresses adhesion of organic or inorganic substances to the surface, or a film that has the effect of enabling the adhesion of organic or inorganic substances to be easily removed by cleaning, such as wiping, even if they are attached to the surface.

[0131] The antifouling film is not particularly limited as long as it can impart antifouling properties, but is preferably a compound containing fluorine, and examples thereof include a fluorine-containing organosilicon compound coating obtained by curing a fluorine-containing organosilicon compound through a hydrolysis and condensation reaction.

[0132] The fluorine-containing organosilicon compound is not particularly limited as long as it can provide antifouling, water repellency, and oil repellency.For example, it can be fluorine-containing organosilicon compound having one or more groups selected from the group consisting of polyfluoropolyether group, polyfluoroalkylene group, and polyfluoroalkyl group.In addition, polyfluoropolyether group means a divalent group having a structure in which polyfluoroalkylene group and etheric oxygen atom are alternately bonded.

[0133] In addition, examples of commercially available fluorine-containing organosilicon compounds include KP-801 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY178 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-130 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-185 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), OPTOOL (registered trademark) DSX, and OPTOOL AES (all trade names, manufactured by Daikin Corporation).

[0134] The thickness of the antifouling film is not particularly limited, but when the antifouling film is made of a fluorine-containing organosilicon compound coating, the thickness is preferably 2 to 20 nm. From the viewpoint of achieving a uniform coverage with the antifouling film and obtaining good abrasion resistance, the thickness is preferably 2 nm or more. Furthermore, from the viewpoint of maintaining good optical properties, the thickness is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less.

[0135] <Size, Shape> The thickness of the glass plate according to this embodiment is not particularly limited, but is usually preferably 5 mm or less from the viewpoint of effectively performing a chemical strengthening treatment. In addition to the above viewpoints, when used as a cover glass for an in-vehicle display device, the thickness of the glass plate is more preferably 3 mm or less from the viewpoint of reducing the weight of the vehicle body, and from the viewpoint of strength, the thickness of the glass plate is preferably 0.2 mm or more, more preferably 0.8 mm or more, and even more preferably 1 mm or more. The size of the glass according to this embodiment is also not particularly limited and may be appropriately determined depending on the application.

[0136] The glass plate according to this embodiment may have a bent portion on at least one of the first principal surface and the second principal surface. The bent portion refers to a portion having a non-zero mean curvature. In this case, it is preferable to form the glass plate into a predetermined shape from a flat glass plate.

[0137] The coefficient of dynamic friction of the bent portion is preferably 0.02 or less, more preferably 0.015 or less, and even more preferably 0.01 or less, from the viewpoint of finger sliding property when a human finger touches the bent portion. Note that the coefficient of dynamic friction of the bent portion in this specification is a value determined by the same method as the average coefficient of dynamic friction COF of the outermost surface of the region having the concave-convex structure of the glass plate.

[0138] <Second Principal Surface> The glass plate according to this embodiment may have a printed layer on at least a portion of the second principal surface. When the glass plate is used as a cover glass for a display device, providing a printed layer can have the effect of clearly indicating button positions to the user and improving operability, and can also have the effect of improving design by concealing wiring for the touch panel. The printed layer is preferably provided on at least a portion of the second principal surface, and is provided using known methods and conditions.

[0139] In addition to the above, the glass plate according to this embodiment may have other functional layers on at least one of the first and second main surfaces, as long as the effects of the present invention are not impaired. Examples of other functional layers include an infrared-cutting layer, an ultraviolet-cutting layer, a water-repellent layer, an antistatic layer, an undercoat layer, an adhesion-improving layer, and a protective layer. These other functional layers may be conventionally known layers formed by known methods.

[0140] <In-Vehicle Display Device> The use of the glass plate according to this embodiment is not particularly limited, and it is used, for example, as a cover glass for a display (such as a notebook PC, a monitor, an LCD, a PDP, an ELD, a CRT, or a PDA). In particular, it is preferably used as a cover glass for an in-vehicle display device because it can be suitably used in applications where the distance between the person viewing the glass plate and the glass plate is fixed and a tactile feel is required when operating a touch panel. Examples of in-vehicle display devices include instrument panels called clusters such as speedometers, CIDs (Center Information Displays) for car navigation systems and display audio systems, and RSEs (Rear Seat Entertainment).

[0141] That is, the present invention also relates to an in-vehicle display device including a cover glass made of the above-mentioned glass plate and a display panel. The display panel includes an illuminant, and examples of the illuminant include organic electroluminescence (EL) displays, OLED (organic light-emitting diodes), liquid crystal display (LCD) light sources, micro-LEDs, and phosphors. That is, examples of the display device include organic EL displays, OLED displays, LCDs, micro-LED displays, and plasma displays.

[0142] The glass plate in the in-vehicle display device is arranged so that the first main surface side of the glass plate is the viewing side. The in-vehicle display device according to this embodiment not only has good visibility but also provides an excellent tactile sensation during a swipe operation.

[0143] <Selection Method> The present invention also relates to a method for selecting the glass plate according to the above-described embodiment when obtaining a glass plate that maintains favorable visibility and also has an excellent tactile feel during a swipe operation. The glass plate according to the above-described embodiment is a glass plate having a first main surface and a second main surface facing the first main surface, and at least a portion of the first main surface has an uneven structure. At the outermost surface of the region having the uneven structure on the first main surface side, the visibility index value T is 0.85 or more, the glare index value S is 0.80 or more, the average dynamic friction coefficient COF is 0.50 or less, and the friction change amount delta is greater than -0.210. In addition, the lightness L of the glass plate ＊ The value is 4.7 or less.

[0144] The preferred aspects of the glass plate in the selection method according to this embodiment are the same as the preferred aspects of the glass plate described above.

[0145] <<Glass Plate Manufacturing Method>> The glass plate manufacturing method according to this embodiment includes the following steps (i) and (ii): (i) preparing a glass plate having a first main surface and a second main surface facing the first main surface, and (ii) forming a concavo-convex structure on at least a part of the first main surface.

[0146] Between the step (i) and the step (ii) or after the step (ii), the method may further include a step (iii) of subjecting the glass plate to a tempering treatment, and the tempering treatment step is preferably performed after the step (ii).

[0147] Furthermore, the method may further include, as step (iv), a step of forming an anti-reflection film so as to cover at least a part of the uneven structure. Step (iv) may be performed after step (ii), but when a strengthening treatment is performed in step (iii), step (iv) is preferably performed after step (iii).

[0148] <Step (i): Step of Preparing a Glass Plate> The glass plate in step (i) may be commercially available or may be manufactured. When manufacturing a glass plate, a conventionally known method can be adopted. For example, raw materials of each component are mixed to obtain a desired composition, and heated and melted in a glass melting furnace. The glass is homogenized by bubbling, stirring, adding a fining agent, etc., and formed into a glass plate of a predetermined thickness by a known forming method, and then slowly cooled.

[0149] Examples of glass forming methods include the float method, press method, fusion method, down-draw method, and roll-out method. Among these, the float method is preferred for mass production. Furthermore, as continuous forming methods other than the float method, the fusion method and down-draw method are also preferred.

[0150] A glass member formed into a flat plate by any molding method is slowly cooled and then cut to the desired size. If more precise dimensional accuracy is required, the cut glass member may be subjected to polishing or edge processing, as described below. This reduces cracking and chipping of the glass plate during handling in the molding process, etc., and improves yield.

[0151] When the glass plate has a bent portion on at least one of the first and second main surfaces, it may be formed into a predetermined shape from a flat glass plate. Forming may be performed while heating the glass, and the forming method may be, for example, gravity forming, vacuum forming, press forming, etc. Note that the glass may be formed before or after step (ii). In particular, when a frosting method or wet blasting method is performed in step (ii), it is preferable to form the glass after step (ii).

[0152] When polishing at least one of the main surfaces of a glass plate, the polishing can be performed, for example, by moving the polishing part of a rotary polishing tool at a constant speed while contacting the glass plate with a constant pressure. By polishing under the conditions of constant pressure and constant speed, the grinding surface can be polished uniformly at a constant polishing rate.

[0153] The edge surfaces of the glass plate may be subjected to edge processing such as chamfering. The chamfering is preferably a processing generally called R-chamfering or C-chamfering by mechanical grinding, but may also be processing by etching or the like, and is not particularly limited.

[0154] <Step (ii): Step of forming a concave-convex structure> In step (ii), a region having a concave-convex structure is formed on at least a portion of the first main surface, and either a chemical treatment or a physical treatment may be employed. Examples of chemical treatment methods include a frosting method, which provides concave-convex structures on the first main surface itself. Examples of physical treatment methods include a two-fluid spray method or an electrostatic spray method, which forms a region having a concave-convex structure on the first main surface. Examples of methods that combine physical treatment and chemical treatment include a wet blasting method, which involves wet blasting followed by etching. In this embodiment, the frosting method and the wet blasting method are particularly preferred.

[0155] Frost Method When forming a textured structure by the frost method, the steps are generally pre-washing, washing, chemical immersion, and washing, in that order. Of the above, the pre-washing and the two washings can be performed by conventionally known methods.

[0156] Among the above, the chemical immersion preferably includes a step of immersing the glass plate in a solution containing potassium fluoride (KF) and hydrogen fluoride (HF), and then a step of immersing the glass plate in a solution containing hydrogen fluoride. Between the immersions in these two types of solutions, washing and drying may be appropriately performed.

[0157] The glass plate is immersed in a solution containing potassium fluoride and hydrogen fluoride to form a frosted surface, and then etched by immersing the glass plate in a solution containing hydrogen fluoride to adjust the transmission haze on the surface of the glass plate.

[0158] The solution used in the frosting process is a mixed solution containing potassium fluoride and hydrogen fluoride, and the potassium fluoride concentration in the mixed solution is preferably 0.5 to 5.0% by mass. From the viewpoint of performing the frosting process sufficiently, the concentration is preferably 0.5% by mass or more, more preferably 0.7% by mass or more, and even more preferably 1.0% by mass or more. Furthermore, from the viewpoint of appropriately roughening the surface structure of the glass plate without excessively refining it and ensuring a high appearance quality, the concentration is preferably 5.0% by mass or less, more preferably 4.5% by mass or less, and even more preferably 4.0% by mass or less.

[0159] The concentration of hydrogen fluoride in the mixed solution is preferably 0.5 to 4.0% by mass. From the viewpoint of sufficiently etching the substrate during the frosting process, the concentration is preferably 0.5% by mass or more, more preferably 0.7% by mass or more, and even more preferably 1.0% by mass or more. Furthermore, from the viewpoint of preventing excessive etching and stripping of masking components formed on the substrate surface, the concentration is preferably 4.0% by mass or less, more preferably 3.5% by mass or less, and even more preferably 3.0% by mass or less.

[0160] In addition, in the mixed solution, the ratio of the potassium fluoride concentration to the hydrogen fluoride concentration (KF / HF) is preferably 0.33 to 3.0. From the viewpoint of precipitating and fixing the mask component on the substrate surface, the ratio is preferably 0.33 or more, more preferably 0.5 or more, and even more preferably 0.75 or more. From the viewpoint of appropriately roughening the surface structure of the glass plate without excessively miniaturizing it and ensuring a high appearance quality, the ratio is preferably 3.0 or less, more preferably 2.0 or less, and even more preferably 1.33 or less.

[0161] The mixed solution may further contain other compounds, and in such cases, fluorides are preferred, such as ammonium fluoride and potassium phosphate. The concentration of each of the other compounds is preferably 15% by mass or less. The mixed solution is an aqueous solution.

[0162] The temperature at which the glass plate is immersed in the solution used for frost processing is preferably 10 to 50° C., more preferably 15 to 40° C. The immersion time is preferably 60 to 360 seconds, more preferably 120 to 240 seconds.

[0163] The solution used in the etching process contains hydrogen fluoride, and the concentration of hydrogen fluoride in the solution is preferably 0.5 to 20% by mass. From the viewpoint of smoothing the tips of the uneven structure formed by the frosting process and efficiently obtaining a suitable shape, the concentration is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more. Furthermore, to prevent ions generated when the substrate is dissolved from bonding with fluorine ions and forming a coating on the substrate surface, the concentration is preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 15% by mass or less.

[0164] The solution may further contain other compounds, and among these, a mixed solution with another acid is preferred from the viewpoint of preventing the substrate from being coated by bonding ions generated when the substrate is dissolved with fluorine ions and dissolving crystals formed on the substrate surface. Examples of the other acid are hydrochloric acid, nitric acid, sulfuric acid, etc. In the case of a mixed solution with another acid, the ratio of the concentration of hydrogen fluoride to the total concentration of the other acids is preferably 0.3 to 3.0, more preferably 0.5 or more, and more preferably 2.0 or less. The solution is an aqueous solution.

[0165] The amount of post-etching by etching cannot be generally determined, but is preferably, for example, 0.5 to 15 μm. Here, from the viewpoint of sufficiently removing contaminant components adhering to the substrate surface, the amount of post-etching is preferably 0.5 μm or more, more preferably 1.0 μm or more. Furthermore, from the viewpoint of not significantly changing the thickness of the substrate, the amount of post-etching is preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 7.0 μm or less.

[0166] By employing the above-described frosting method, a glass plate can be obtained in which, on the outermost surface of the region having the uneven structure, a visibility index value T of 0.85 or more and a glare index value S of 0.80 or more are maintained, while an average dynamic friction coefficient COF of 0.50 or less and a friction change amount delta of more than -0.210 are realized. Furthermore, by employing the above-described frosting method, a glass plate can be obtained in which, with respect to the surface roughness of the outermost surface, the element mean length Rsm of the roughness curve is less than 26 μm, the arithmetic mean roughness Ra is 0.12 μm or more, the skewness Rsk is -1 to 1, and the kurtosis Rku is 2 to 4.

[0167] The transmission haze of the outermost surface of the region having the concave-convex structure of the glass plate obtained as described above is 15% or more. However, by forming an absorptive anti-reflection film so as to cover the concave-convex structure, the whiteness of the substrate is suppressed and the brightness L ＊ The value can be reduced to 4.7 or less.

[0168] Wet Blasting Method When forming a textured structure by wet blasting, a glass plate, preferably a polished glass plate, is generally subjected to wet blasting, followed by cleaning, etching, cleaning, and other steps.

[0169] Of the above, the wet blasting process preferably includes a step of spraying a slurry onto the first main surface of the glass plate to roughen it, and a subsequent step of immersing the glass plate in a solution containing hydrogen fluoride to etch it. Washing and drying may be performed as appropriate between the roughening step and the etching step.

[0170] In the roughening process, a slurry made by mixing a liquid such as water with abrasive particles (abrasive grains) is pumped into a blast gun, accelerated with compressed air, and then sprayed onto the first main surface of the glass plate to perform surface roughening, processing, cleaning, peening, etc.

[0171] By appropriately changing the abrasive particle size, abrasive particle distribution, abrasive particle type, abrasive particle concentration, discharge pressure, discharge time, sweep speed, number of sweeps, sweep pitch, spray angle, spray distance, etc. of the particles (abrasive particles) used in the roughening process, optical properties for maintaining good visibility and preferable conditions for achieving a good tactile feel can be determined.

[0172] Among the above conditions, it was found that by making the spray angle of the slurry more oblique than conventional methods, the occurrence of lateral cracks can be suppressed and median cracks can be made the main focus. By making median cracks the main focus, a concave-convex structure with a large aspect ratio can be formed when the subsequent etching process is performed, and the average coefficient of dynamic friction COF can be made small and the lightness L can be made the main focus. ＊ A glass plate with a small value can be obtained.

[0173] From the above viewpoint, the spray angle of the slurry with respect to the first main surface is preferably less than 90°, more preferably 70° or less, and even more preferably 65° or less. Furthermore, from the viewpoint of sufficiently introducing cracks, the spray angle is preferably 45° or more, and more preferably 50° or more.

[0174] It has been found that conditions such as abrasive grain size and discharge pressure, other than or in addition to the above-mentioned blast angle, are also very effective in suppressing the occurrence of lateral cracks.

[0175] The abrasive grain type can be any known type, such as alumina or silicon carbide. The abrasive grain size varies depending on the type of abrasive grain. For example, when using alumina, the grain size according to JIS R 6001 (1987) is preferably equal to or smaller than the average grain size of #1500 (larger number), more preferably equal to or smaller than the average grain size of #2000 (larger number). The lower limit of the grain size is not particularly limited, but the grain size is preferably equal to or larger than the average grain size of #6000.

[0176] The discharge pressure is preferably 0.1 to 0.6 MPa. From the viewpoint of introducing sufficiently deep cracks into the substrate surface, the discharge pressure is preferably 0.1 MPa or more, more preferably 0.15 MPa or more, and even more preferably 2.0 MPa or more. Furthermore, from the viewpoint of preventing chipping and damage to the discharge portion, the discharge pressure is preferably 0.6 MPa or less, more preferably 0.5 MPa or less, and even more preferably 0.4 MPa or less.

[0177] The abrasive concentration is preferably 5 to 20% by volume. From the viewpoint of introducing a sufficient amount of cracks into the substrate surface, the abrasive concentration is preferably 5% by volume or more, more preferably 7% by volume or more, and even more preferably 10% by volume or more. Furthermore, from the viewpoint of sufficiently dispersing the abrasive in the liquid, the abrasive concentration is preferably 20% by volume or less, more preferably 17% by volume or less, and even more preferably 15% by volume or less.

[0178] The number of sweeps is preferably 2 to 64. From the viewpoint of eliminating sweep unevenness in wet blasting, the number of sweeps is preferably 2 or more, more preferably 4 or more, and even more preferably 8 or more. Furthermore, from the viewpoint of keeping the processing time within a practical range, the number of sweeps is preferably 64 or less, more preferably 48 or less, and even more preferably 32 or less.

[0179] In the etching step, a solution containing hydrogen fluoride is used, and the concentration of hydrogen fluoride in the solution is preferably 0.5 to 20% by mass. From the viewpoint of expanding cracks introduced by wet blasting and obtaining a suitable shape, the concentration is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more. Furthermore, from the viewpoint of preventing ions generated when the substrate dissolves at the tip of the crack from combining with fluorine ions to form difficult-to-etch crystals, which inhibit etching and change the crack shape, the concentration is preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 15% by mass or less.

[0180] The solution may further contain other compounds, such as hydrochloric acid and sulfuric acid. The concentration of the other compounds is preferably 15% by mass or less. The solution is an aqueous solution.

[0181] The amount of etching in the etching step cannot be generally determined, but is preferably 1.0 to 30 μm, and more preferably 2.0 to 20 μm, for example.

[0182] By adopting the wet blasting method as described above, the outermost surface of the region having the uneven structure has a visibility index value T of 0.85 or more, a glare index value S of 0.80 or more, and a brightness L ＊A glass plate having a good tactile feel when swiped, such as an average coefficient of dynamic friction COF of 0.50 or less and a friction change delta of more than -0.210, while maintaining good optical properties with a value of 4.7 or less, can be obtained. Furthermore, by employing the above-described wet blasting method, a glass plate can be obtained in which the surface roughness of the outermost surface is such that the element mean length Rsm of the roughness curve is 26 μm or more, the skewness Rsk is -4 to -1.5, and the kurtosis Rku is 5 to 20.

[0183] Furthermore, when the uneven structure is formed by the wet blasting method, for example, by setting the spray angle of the slurry to 70° or less with respect to the first main surface, the transmission haze can be reduced to 15% or less while realizing the above-mentioned good optical properties and tactile feel. On the other hand, even when the wet blasting method is used and the transmission haze at the outermost surface of the region having the uneven structure exceeds 15%, by forming the above-mentioned absorptive antireflection film so as to cover the uneven structure, as in the case of forming the uneven structure by the frosting method, the whiteness of the substrate can be suppressed and the brightness L ＊ The value can be reduced to 4.7 or less.

[0184] <Step (iii): Step of Tempering Treatment> When the glass plate is subjected to the step (iii), which is a tempering treatment, the step (iii) may be performed between the above step (i) and step (ii), but is preferably performed after the step (ii).

[0185] By subjecting at least one of the first and second main surfaces of the glass plate to a tempering treatment, a compressive stress layer is formed on the surface, thereby increasing the strength and scratch resistance. Either physical tempering or chemical tempering can be applied as the tempering treatment, and chemical tempering is preferred because it can introduce more compressive stress even into a thin glass plate.

[0186] Chemical strengthening involves immersing a glass plate in molten alkali metal salt at a temperature below the glass transition point, thereby exchanging alkali metal ions with a small ionic radius present on the surface of the glass plate for alkali metal ions with a larger ionic radius. Specifically, Li ions on the surface of the glass plate are exchanged for Na ions, or Na ions on the surface of the glass plate are exchanged for K ions. This allows a compressive stress layer to be formed on the surface of the glass plate. Conventional molten salts and treatment conditions for the chemical strengthening treatment can be used.

[0187] <Step (iv): Step of forming an anti-reflective film> In step (iv), an anti-reflective film is optionally formed on a glass plate having a concave-convex structure formed on its surface, or on a glass plate having a concave-convex structure formed on its surface and further subjected to chemical strengthening treatment. When forming the anti-reflective film, it is sufficient to form it so as to cover at least a part of the concave-convex structure, and it is preferable to form it so as to cover an area of ​​the glass plate that is visible and that is touched for swiping actions, etc.

[0188] Even when the transmission haze is high on the outermost surface of the region having the uneven structure of the glass plate, by forming the absorptive antireflection film described in the first embodiment in the above-mentioned <First embodiment and second embodiment>, the brightness L ＊ This allows for lower values ​​and good visibility.

[0189] The anti-reflection film can be formed by a conventionally known method. For example, a dielectric layer or layers can be sequentially formed and stacked on the surface of the first main surface of the glass plate using a known film formation method such as sputtering, vacuum deposition, coating, chemical vapor deposition (CVD), or physical vapor deposition (PVD) such as PLD, to obtain the anti-reflection film. An anti-reflection film may also be formed on the surface of the second main surface of the glass plate.

[0190] Examples of sputtering methods include magnetron sputtering, pulse sputtering, AC sputtering, and digital sputtering.

[0191] Among the above methods, for example, magnetron sputtering is a method in which a magnet is placed on the backside of the dielectric layer or the base material of the layer to generate a magnetic field, and gas ion atoms collide with the surface of the material and are ejected, thereby forming a sputtering film with a thickness of several nanometers, which can form a continuous dielectric film that is an oxide or nitride of the material.

[0192] Among the above, for example, digital sputtering is a method in which an ultrathin metal film is first formed by sputtering, and then the process of oxidizing the film by irradiating it with oxygen plasma, oxygen ions, or oxygen radicals is repeated in the same chamber to form a thin film of metal oxide. In this case, the film-forming molecules are metal when deposited on the substrate, so it is presumed to be more ductile than when a film is deposited as a metal oxide. Therefore, even with the same energy, the film-forming molecules are more likely to rearrange, resulting in the formation of a dense and smooth film.

[0193] In the coating method, for example, a composition that serves as a precursor of a layer that constitutes the antireflection film is applied by a spin coating method, a dip coating method, a casting method, a slit coating method, a spray coating method, an electrostatic spray deposition method (ESD method), or the like, and then a heat treatment is performed as necessary, and this method is repeated to form a laminated structure.

[0194] In addition to the above steps (i) to (iv), conventionally known methods can also be used when forming an antifouling film (AFP film). For example, a method in which a composition of a silane coupling agent having a fluoroalkyl group such as a perfluoroalkyl group or a fluoroalkyl group containing a perfluoro(polyoxyalkylene) chain is applied by spin coating, dip coating, casting, slit coating, spray coating, or the like, followed by heat treatment as needed, or a vacuum deposition method in which a fluorine-containing organosilicon compound is vapor-deposited on the surface of the adhesive layer, followed by heat treatment as needed, can be mentioned.

[0195] The composition serving as a precursor of the antifouling film is not particularly limited as long as it contains a fluorine-containing hydrolyzable silicon compound and can form a film. The composition may contain optional components other than the fluorine-containing hydrolyzable silicon compound.

[0196] The optional components are not particularly limited as long as they do not inhibit the effects of the present invention, and examples thereof include hydrolyzable silicon compounds that do not contain fluorine atoms (hereinafter referred to as "non-fluorine hydrolyzable silicon compounds"), catalysts, etc.

[0197] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following descriptions. Examples 1 to 6 and 10 are working examples, and Examples 7 to 9 and 11 to 16 are comparative examples.

[0198] <Evaluation Method> The following evaluations were performed for each example. Measurements were made at three arbitrary points along the diagonal of the glass plate to determine each physical property value, and the average value was used.

[0199] <Average dynamic friction coefficient COF, friction change delta> Using a static friction measuring instrument (Trinity Labs, multi-function static friction measuring instrument TL201), the dynamic friction coefficient was measured by sliding a dummy finger on the outermost surface of the region having an uneven structure on the first main surface side of the glass plate at a scanning distance of 50 mm, a load of 100 g, and a scanning speed of 100 mm / s at a room temperature of 23 ° C and a humidity of 21%. The data acquisition frequency was 1 kHz, and the number of samplings was 5. The dummy finger was made of urethane (Trinity Labs, urethane dummy finger), and the contact portion with the outermost surface of the glass plate was formed at 0.5 mm intervals in an area of ​​10 × 15 mm, in a direction perpendicular to the sliding direction. Here, going back from the time when the dynamic friction coefficient is at its maximum, the time when the dynamic friction coefficient first becomes 0 or less was defined as the movement start time, and the time when the dynamic friction coefficient first becomes 5 or less after the time expressed by {(movement start time) + (0.75 × scanning distance / scanning speed)} was defined as the movement end time. The value calculated by the following formula (3) was defined as the average dynamic friction coefficient COF, and the value calculated by the following formula (4) was defined as the friction change amount delta. Average dynamic friction coefficient COF = average value of dynamic friction coefficients at (midpoint between the movement start time and the movement end time) ± 0.2 seconds Formula (3) Friction change amount delta = (maximum dynamic friction coefficient after the movement end time) - (average dynamic friction coefficient COF) Formula (4)

[0200] <Visibility index value T> A glass plate (100 mm x 100 mm x 1.3 mmt) was placed 30 mm away from a slit-shaped white light source having a length of 40 mm and a width of 0.1 mm, with the first main surface side facing the light source. Then, from the second main surface side of the glass plate, the light transmitted through the glass plate and the angle θ were detected using an SMS-1000 (analysis device) manufactured by DM&S (Display-Messtechnik & Systeme), and the brightness at the outermost surface of each area having a concave-convex structure was measured. The camera lens used was a C1614A lens with a focal length of 16 mm and an aperture of 5.6, and the distance from the outermost surface of the first main surface side of the glass plate to the camera lens was set to 550 mm. When the angle θ = 0 ° is set to the direction parallel to the thickness direction of the glass plate, the average brightness value in the range of angle θ = 0 ° ± 0.1 ° was calculated as T. １ The average value of the luminance in the range of angle θ=0.7°±0.1° is T ２ The average value of the luminance in the range of angle θ = −0.7°±0.1° is T ３ In this case, the value calculated by the following formula (1) was defined as the visibility index value T. Visibility index value T=1−(T ２ +T ３ ) / (2 x T １ ) Formula (1)

[0201] <Glare index value S> A glass plate (100 mm x 100 mm x 1.6 mm) was placed so that its second main surface was in contact with the display surface side of a display device (iPad-Air (registered trademark), manufactured by Apple Inc.) with a resolution of 264 ppi. With a green monochromatic image composed of RGB (0, 255, 0) displayed on the display device, the sparkle value on the outermost surface of the region having the uneven structure was determined by image analysis using an SMS-1000 manufactured by DM&S Co., Ltd., placed on the first main surface side of the glass plate, and the glare index value S was calculated. ａThe distance d between the SMS-1000 manufactured by DM&S and the outermost surface on the first main surface side of the glass plate was set to 540 mm, and a 23FM50SP lens with a focal length of 50 mm was used as the camera lens at an aperture of 5.6. Image analysis was also performed under the same conditions on a glass substrate (VRD140 glass; manufactured by AGC Glass Europe) of the same size (100 mm x 100 mm x 1.6 mmt) as a reference sample, and the obtained Sparkle value was used as the glare S. ｓ I decided to do so. ａ and S ｓ The value calculated from the value of (S) using the following formula (2) was taken as the glare index value S. ａ / S ｓ ) Formula (2)

[0202] <Reflected Image Diffusion Index Value R> A glass plate (100 mm × 100 mm × 1.3 mmt) was placed with the first principal surface facing up, and a 101 mm-wide slit-shaped light was emitted from above. The luminance of the reflected light obtained was measured using an SMS-1000 manufactured by DM&S. At this time, a matte black plate was placed on the second principal surface side to eliminate reflected light from the second principal surface side (rear surface reflection). A C1614A lens with a focal length of 16 mm was used as the camera lens, with an aperture of 5.6. The distance from the outermost surface of the first principal surface of the glass plate to the camera lens was 300 mm, and the imaging scale was set to a range of 0.0276 to 0.0278. When the angle φ is set to 0° in the direction parallel to the thickness direction of the glass plate, light is emitted from an angle φ = 5.7° ± 0.1°, and the angle φ = -5.7° at the time of total reflection is set as the reference (angle α = 0°). The average brightness of the reflected light in the range of angle α = 0° ± 0.1° is defined as R １ , the average brightness of the reflected light in the range of angle α = 0.5° ± 0.1° is R ２ , the average brightness of the reflected light in the range of angle α = −0.5° ± 0.1° is R ３ In this case, the value calculated by the following formula (5) was taken as the reflected image diffuseness index value R. ２ +R ３ ) / (2 x R １ ) Formula (5)

[0203] <Lightness L ＊The whiteness of the glass plate was evaluated by the brightness L measured by the specular elimination (SCE) method using a CM-26d manufactured by Konica Minolta in accordance with the ASTM E313-73 standard. ＊ Specifically, the measurement port of the measuring device was placed in contact with the glass plate so that external light would not enter, light was irradiated onto the glass plate from a specified light source, and the spectrum of the light reflected from the glass plate was detected by a photodetector. ＊ a ＊ b ＊ By calculating the color system, the lightness L ＊ got the value.

[0204] <Surface Roughness> On the outermost surface of the region having a concave-convex structure of a glass plate, the element mean length Rsm of the roughness curve, the arithmetic mean roughness Ra, the skewness Rsk, the kurtosis Rku, and the maximum cross-sectional height Rt, which are indicators of surface roughness, were each measured in accordance with JIS B 0601 (2013). Specifically, using a VK-X3000 manufactured by Keyence Corporation, a 50x objective lens was used to image a 280 μm × 200 μm field of view of the substrate after the concave-convex structure was formed and before the anti-reflection film was formed. Images were obtained by applying plane tilt correction to the entire image without using a cutoff. For that image, 21 straight lines were defined across the entire width of the image in the horizontal direction of the Y axis at 10 μm intervals, and 21 Rsm, Ra, Rsk, Rku, and Rt were calculated from their cross-sectional profiles, and the average value was taken as a single value of Rsm, Ra, Rsk, Rku, and Rt on the outermost surface of the glass plate. Similar operations were performed, as described above, at any three locations on the diagonal of the glass plate, and the average values ​​were taken as the values ​​of Rsm, Ra, Rsk, Rku, and Rt. Note that this measurement was performed before the anti-reflection film was formed, but since the anti-reflection film is formed following the unevenness of the glass plate and does not significantly affect each parameter of surface roughness, it can be considered as a value measured after the anti-reflection film was formed.

[0205] <Transmission Haze> The transmission haze of the outermost surface of the region of the glass plate having the uneven structure and the anti-reflection film was measured by a method conforming to JIS K 7136 (2000). Specifically, the glass plate was placed on a light source with the first main surface side facing the light source, and the transmitted light was measured from above the glass plate using a haze meter HZ-1 manufactured by Suga Test Instruments Co., Ltd. When the direction parallel to the thickness direction of the glass plate is defined as an angle of 0°, the light detected within ±2.5° was defined as transmitted light, and the light detected at an angle of less than -2.5° or more than +2.5° was defined as scattered light (transmitted light loss). The sum of the transmitted light and scattered light, i.e., the proportion of the scattered light to the total light transmission, was defined as the transmission haze (%).

[0206] <Luminous transmittance of outermost surface> The luminous transmittance measured on the outermost surface on the first principal surface side of the region having an antireflection film covering the uneven structure of the glass plate was measured by a method conforming to JIS Z 8701 (1999). Specifically, the spectral transmittance was measured using a spectrophotometer (manufactured by Shimadzu Corporation, product name: SolidSpec-3700), and the luminous transmittance, i.e., the stimulus value Y defined in JIS Z 8701 (1999), was calculated and used as the luminous transmittance.

[0207] <Glass plate b ＊ Value > b of glass plate ＊ The value was measured by a method conforming to JIS Z 8729 (2004). Specifically, the color index (b ＊ The D65 light source was used.

[0208] <Luminous reflectance of outermost surface> The luminous reflectance measured on the outermost surface on the first principal surface side of the region having an antireflection film covering the concave-convex structure of the glass plate was measured by a method conforming to JIS Z 8701 (1999). Specifically, the spectral reflectance of the outermost surface on the first principal surface side of the region having an antireflection film covering the concave-convex structure was measured using a spectrophotometer (manufactured by Shimadzu Corporation, product name: SolidSpec-3700), and the luminous reflectance, i.e., the reflection stimulus value Y defined in JIS Z 8701 (1999), was calculated. The second principal surface side of the glass plate was painted black with lacquer to eliminate backside reflection during the measurement.

[0209] <Sheet Resistance of Antireflection Film> The sheet resistance of the antireflection film provided on the first main surface side of the glass plate was measured by a method in accordance with JIS K 6271-6 (2008). Specifically, using a measuring device (manufactured by Mitsubishi Chemical Analytech Co., Ltd., device name: Hiresta UP (MCP-HT450 type)), a probe was placed at the center of the antireflection film, and a current of 10 V was applied for 10 seconds to measure the sheet resistance of the antireflection film.

[0210] <60° Specular Gloss (%)> The 60° specular gloss (%) of the outermost surface on the first principal surface side of the glass plate was measured by a method conforming to JIS Z 8741 (1997). Specifically, using an all-in-one glossmeter (Rhopoint IQ, manufactured by Rhopoint Instruments), the 60° specular gloss was measured at approximately the center of the plane of the area having the uneven structure and anti-reflection film formed on the surface on the first principal surface side of the glass plate. At this time, black felt was placed on the second principal surface side of the glass plate to eliminate backside reflection of the glass plate.

[0211] <Tactile Sensation> A sensory evaluation was performed on the tactile sensation of a swipe on the outermost surface of the region of the glass plate having the concave-convex structure and the anti-reflection film. Specifically, a single-finger swipe and a two-finger swipe (pinching in and pinching out) were performed on the outermost surface. The panel evaluated the finger slippage during the single-finger swipe and the ease with which the fingers stopped when the two-finger swipe was completed. The panel consisted of 174 people, and each gave a pass / fail rating and a score of 0 to 10 points to the tactile sensation of each glass plate. The average score was used as the tactile rank. As a result of the sensory evaluation, a tactile rank of 2 or more was considered to be acceptable, and a higher tactile rank was preferable.

[0212] Test Examples Examples 1 to 9 A glass plate (DRAGONTRAIL (registered trademark), manufactured by AGC Inc.) having a thickness of 1.3 mm was cut into pieces measuring 500 mm x 400 mm using a diamond cutter. Sharp edges resulting from the cutting were ground using a diamond grinding wheel with a grit size of 400 in accordance with JIS R 6001 (1987) to form a C-chamfered shape.

[0213] Next, one of the main surfaces (first main surface) of the glass plate was subjected to an anti-glare treatment by wet blasting using the following procedure. Alumina particles were used as abrasive grains, and a slurry was prepared by dispersing the abrasive grains in water so that the abrasive grain concentration (alumina particle concentration) was 12% by volume. The particle size of the alumina grains according to JIS R 6001 (1987) is as shown in Table 1.

[0214] The slurry was pumped into a blast gun and accelerated with compressed air before being sprayed onto the first main surface of the glass plate to roughen the surface by wet blasting. The discharge pressure, spray angle of the slurry relative to the first main surface, and number of sweeps during roughening were as shown in Table 1. In all examples, the projection distance was 70 mm and the transport speed was 20 mm / s.

[0215] After wet blasting, the glass plate was washed with water, and then etched with hydrofluoric acid and washed to obtain a glass plate having a textured structure on the first principal surface. The concentration of hydrogen fluoride in the hydrofluoric acid was 5.0 mass %, and the immersion time was adjusted so that the amount of etching by hydrofluoric acid was the value shown in Table 1.

[0216] Next, an anti-reflection film was formed on the entire surface of the first main surface having the concave-convex structure formed above. In Examples 1 and 9, a total of four low-refractive index layers and high-refractive index layers shown below were alternately formed by magnetron sputtering to provide the anti-reflection film. The outermost layer was SiO ２ Low refractive index layer: SiO ２ High refractive index layer: Nb ２ O ５ layer, refractive index at wavelength 550 nm 2.3

[0217] Specifically, the anti-reflection coatings of Examples 1 and 9 were formed by the following procedure. Each of the above layers was formed by sputtering. ２ O ５ The layer was 14 mm thick and made of SiO ２ The layer is 38 mm thick and made of Nb ２ O ５ The layer was 119 mm thick and SiO ２ The conditions were adjusted so that the layers were formed in order to a thickness of 87 mm. Each layer was laminated by a flow method. During film formation, a mixed gas of argon gas and 10% by volume of oxygen gas was introduced into the chamber, and the pressure was 0.3 Pa, the frequency was 20 kHz, and the film formation power was 3.8 W / cm. ２ Magnetron sputtering was carried out with a reverse pulse width of 5 μsec, and each layer was deposited over the entire surface of the first main surface having the uneven structure.

[0218] In Examples 2 to 8, a total of four layers, namely, a high refractive index layer (1), a low refractive index layer (1), a high refractive index layer (2), and a low refractive index layer (2), shown below, were formed in this order on the formed uneven structure using a pulse sputtering method to form an anti-reflection film. The outermost layer was the low refractive index layer (1). High refractive index layer (1): Mo—Nb—O layer, thickness 14 nm, refractive index at a wavelength of 550 nm: 2.1 Low refractive index layer (1): SiO ２ High refractive index layer (2): Mo—Nb—O layer, thickness 120 nm, refractive index at wavelength 550 nm 2.1) Low refractive index layer (2): SiO ２ layer, thickness 90 nm, refractive index at wavelength 550 nm 1.47)

[0219] Specifically, the anti-reflective coatings of Examples 2 to 9 were formed by the following procedure. While introducing a mixed gas of argon gas and 39% by volume of oxygen gas, the pressure was kept at 0.3 Pa, and pulse sputtering was performed using a target made by mixing and sintering niobium and molybdenum in a weight ratio of 80:20. The sputtering conditions were a frequency of 20 kHz and a power density of 4.0 W / cm. ２ The inversion pulse width was set to 5 μsec. As a result, a Mo—Nb—O layer was formed to a thickness of 14 nm so as to cover the uneven structure of the glass plate. The composition ratio of Mo to Nb in the obtained Mo—Nb—O layer was Mo:Nb=80:20 (mass %).

[0220] Next, pulse sputtering was performed using a silicon target while introducing a mixed gas of argon gas and 40% by volume of oxygen gas under the following conditions: pressure 0.3 Pa, frequency 20 kHz, power density 3.8 W / cm. ２ The inversion pulse width was set to 5 μsec. This resulted in a silicon oxide (silica (SiO ２ )) was deposited.

[0221] Next, while introducing a mixed gas of argon gas and 10% by volume of oxygen gas, the pressure was kept at 0.3 Pa, and pulse sputtering was carried out using a target made by mixing and sintering niobium and molybdenum in a weight ratio of 80:20. The sputtering conditions were a frequency of 20 kHz and a power density of 4.0 W / cm.２ The reverse pulse width was set to 5 μsec. As a result, a Mo—Nb—O layer was formed to a thickness of 120 nm. The composition ratio of Mo to Nb in the obtained Mo—Nb—O layer was Mo:Nb=80:20 (mass %).

[0222] Subsequently, pulse sputtering was performed using a silicon target while introducing a mixed gas of argon gas and 39% by volume of oxygen gas under the conditions of a pressure of 0.3 Pa, a frequency of 20 kHz, and a power density of 3.8 W / cm. ２ The inversion pulse width was set to 5 μsec. This resulted in a silicon oxide (silica (SiO ２ )) was deposited.

[0223] In Examples 1 to 9, an antifouling film was further formed on the glass plate on which the antireflection film had been formed, so as to cover the entire surface of the antireflection film. The antifouling film was formed by the following procedure. As the material for the antifouling layer, a material for forming a fluorine-containing organosilicon compound film was introduced into a heating container of an antifouling layer formation chamber. S-550 (manufactured by AGC Inc.) was used as the composition for forming the antifouling layer. Next, the glass plate on which the antireflection film had been formed was placed in a vacuum chamber, and then the composition for forming an antifouling layer was supplied toward the first main surface, and a film was formed to a thickness of 4 nm.

[0224] According to the above procedure, glass plates of Examples 1 to 9 were obtained.

[0225] <Examples 10 to 16> In Examples 10 to 15, one main surface (first main surface) of the glass plate was subjected to anti-glare treatment by a frosting method according to the following procedure. In Example 16, no anti-glare treatment was performed.

[0226] In the anti-glare treatment using the frosting method, the glass plate was first pre-washed by immersing it in 5% by mass hydrofluoric acid for 180 seconds. It was then washed with pure water, dried, and then frosted. The frosting was performed by immersing it in a mixed solution of potassium fluoride and hydrogen fluoride at 15°C for 180 seconds. The concentrations of potassium fluoride and hydrogen fluoride in the mixed solution were as shown in Table 2.

[0227] The specimen was then washed with pure water, dried, and then etched. The etching was performed by immersing the specimen in a mixed solution of hydrogen fluoride and hydrochloric acid at 15°C. The hydrogen fluoride concentration in the mixed solution was 10 mass% and the hydrochloric acid concentration was 4 mass%. The immersion time was adjusted so that the post-etching amount due to the etching process would be the value shown in Table 2.

[0228] Thereafter, the glass plate was washed with pure water and dried to obtain a glass plate having an uneven structure on the first main surface.

[0229] Next, an antireflection film was formed over the entire first principal surface having the concavo-convex structure formed above in Examples 10 to 15, and over the entire one principal surface in Example 16. Specifically, an antireflection film was formed in Examples 10 to 12 in the same manner as in Examples 2 to 8, and in Examples 13 to 16 in the same manner as in Examples 1 and 9.

[0230] Next, an antifouling film was formed on the glass plate on which the antireflection film had been formed so as to cover the entire surface of the antireflection film in the same manner as in Examples 1 to 9, thereby obtaining glass plates of Examples 10 to 16.

[0231] The evaluation results of the obtained glass plates are shown in Tables 1 and 2. In addition, for all of the glasses of Examples 1 to 16, the sheet resistance of the anti-reflection film was 10 ４ It was Ω / □ or more.

[0232]

[0233]

[0234] From the above results, it was found that even if the average dynamic friction coefficient COF value is within an appropriate range, a glass plate with a small friction change delta has a poor tactile feel during a swipe operation. ＊ It was found that by setting the value within an appropriate range, good visibility can also be maintained.

[0235] A glass plate that satisfies these characteristics correlates with the surface roughness and transmission haze values. In conventional glass plate manufacturing methods, in order to obtain an excellent tactile feel, the transmission haze increases, and a sufficiently low lightness L ＊However, the inventors have found that, when forming the uneven structure by using the wet blasting method, it is possible to achieve both an excellent feel and a small transmission haze by reducing the spray angle of the slurry. ＊ There is a correlation with the value, and when the transmission haze is large, the lightness L ＊ However, by forming the above-mentioned absorptive anti-reflection film, even if the transmission haze is large, the whiteness of the substrate can be suppressed and a sufficiently low brightness L ＊ It was found that the value could be achieved.

[0236] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. This application is based on a Japanese patent application (Patent Application No. 2023-106110) filed on June 28, 2023, the contents of which are incorporated herein by reference.

[0237] By applying the glass plate according to the present invention to a display device, excellent visibility is maintained while also providing an excellent tactile feel, and therefore the glass plate can be suitably used in a display device having a touch panel function.

[0238] 50 Glass plate 51 Black plate 52 First main surface 53 Second main surface 54 Display device 70A, 70B, 70C Measuring device 71 Light source 75 Detector (analysis device) 731 Second light 733 First reflected light 735 Second reflected light 737 Third reflected light

Claims

1. A glass plate having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface has an uneven structure on at least a portion thereof, and the outermost surface of the region having the uneven structure on the first main surface side has a visibility index value T of 0.85 or more, a glare index value S of 0.80 or more, an average dynamic friction coefficient COF of 0.50 or less, and a friction change amount delta of more than -0.210, and the lightness L of the glass plate measured by a method conforming to the ASTM E313-73 standard using a specular elimination (SCE) method is ＊ A glass plate having a visibility index value T of 4.7 or less, and the visibility index value T, the glare index value S, the average dynamic friction coefficient COF, and the friction change amount delta are quantified by the following methods. Visibility index value T: Using SMS-1000 manufactured by DM&S, the glass plate is placed at a position 30 mm away from a slit-shaped white light source having a length of 40 mm and a width of 0.1 mm, so that the first main surface side is the light source side, and the luminance at the outermost surface of the region having the uneven structure is measured from the second main surface side of the glass plate. A camera lens having a focal length of 16 mm is used with an aperture of 5.6, and the distance from the outermost surface of the first main surface side of the glass plate to the camera lens is set to 550 mm. The direction parallel to the thickness direction of the glass plate is defined as angle θ=0°, and the average brightness in the range of angle θ=0°±0.1° is defined as T １ The average luminance in the range of angle θ=0.7°±0.1° is T ２ The average luminance in the range of angle θ = -0.7°±0.1° is T ３ In this case, the value calculated by the following formula (1) is defined as the visibility index value T. ２ +T ３ ) / (2 x T １ ) Formula (1) Glare index value S: The glass plate is arranged so that the second main surface is in contact with the display surface side of a display device with a resolution of 264 ppi. In a state where a green monochromatic image composed of RGB (0, 255, 0) is displayed on the display device, the sparkle value at the outermost surface of the region having the uneven structure, which is obtained by image analysis using an SMS-1000 manufactured by DM&S Co., Ltd., installed on the first main surface side of the glass plate, is defined as the glare S. ａ Let us assume that. The distance d between the SMS-1000 manufactured by DM&S and the outermost surface on the first main surface side of the glass plate was set to 540 mm, and the camera lens used had a focal length of 50 mm and an aperture of 5.

6. In addition, image analysis was performed under the same conditions on a glass substrate (VRD140 glass manufactured by AGC Glass Europe) having the same thickness as the glass plate as a reference sample, and the obtained Sparkle value was used as the glare S. ｓ Let us assume that. ａ and S ｓ The value calculated from the value of (S) using the following formula (2) is defined as the glare index value S. ａ / S ｓ Average dynamic friction coefficient COF, friction change delta: In a static and dynamic friction measuring device, the dynamic friction coefficient is measured by sliding a dummy finger on the outermost surface of the region having the concave-convex structure on the first main surface side of the glass plate at a scanning distance of 50 mm, a load of 100 g, and a scanning speed of 100 mm / sec in an environment of room temperature 23° C. and humidity 21%. The data acquisition frequency is 1 kHz. The artificial finger is made of urethane, and the contact portion with the outermost surface is formed with linear convex portions at 0.5 mm intervals in a direction perpendicular to the sliding direction within an area of ​​10×15 mm. Here, the time when the dynamic friction coefficient becomes 0 or less for the first time, going back from the time when the dynamic friction coefficient becomes maximum, is defined as the movement start time, and the time when the dynamic friction coefficient becomes 5 or less for the first time after the time represented by {(the movement start time)+(0.75×the scanning distance / the scanning speed)} is defined as the movement end time. The value calculated by the following formula (3) is defined as the average dynamic friction coefficient COF, and the value calculated by the following formula (4) is defined as the friction change amount delta. Average dynamic friction coefficient COF=average value of dynamic friction coefficients at (middle time between the movement start time and the movement end time)±0.2 seconds Formula (3) Friction change amount delta=(maximum dynamic friction coefficient after the movement end time)−(the average dynamic friction coefficient COF) Formula (4) 2. The first main surface further has an anti-reflection film on at least a part thereof, the anti-reflection film covers at least a part of the uneven structure, the luminous transmittance measured on the outermost surface of the first main surface side of the region of the glass plate having the anti-reflection film is 20 to 85%, and the luminous transmittance of the region of the glass plate having the anti-reflection film under a D65 light source measured in accordance with JIS Z 8729 (2004) is 20 to 85%. ＊ a luminous reflectance value of 5 or less, a luminous reflectance measured on the outermost surface on the first principal surface side of a region of the glass plate having the antireflection film covering the uneven structure is 1% or less, and a sheet resistance of the antireflection film is 10 ４ The glass plate according to claim 1 , having a resistance of Ω / □ or more.

3. The glass plate according to claim 2, wherein a transmission haze measured by a method in accordance with JIS K 7136 (2000) is 15% or more on an outermost surface of a region on the first main surface side having the uneven structure and the antireflection film.

4. The glass plate according to claim 2, wherein the anti-reflection film has a laminated structure in which two or more dielectric layers having different refractive indices are alternately laminated, the main components of the dielectric layers in the laminated structure are at least one oxide selected from the group consisting of Si, Nb, Ti, Zr, Ta, Al, Sn and In, or at least one nitride of Si and Al, and at least one of the dielectric layers has dispersed therein at least one fine particle selected from the group consisting of Ag, Mo, W, Cu, Au, Pd, Pt, Ir, Ni, Co, Fe, Cr, C, TiC, SiC, TiN and CrN.

5. The glass plate according to claim 2, wherein the anti-reflection film has a laminated structure in which two or more layers having different refractive indices are alternately laminated, at least one of the layers in the laminated structure has a main component of an oxide of Si, and at least one other of the layers in the laminated structure has a main component of a mixed oxide of at least one oxide selected from Group A consisting of Mo and W, and at least one oxide selected from Group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn and In, and the content of the elements in Group B in the mixed oxide relative to the total of the elements in Group A and the elements in Group B is less than 50 mass%.

6. The glass plate according to claim 2, wherein, at an outermost surface of a region on the first main surface side having the uneven structure and the anti-reflection film, the surface roughness has an element mean length Rsm of a roughness curve of less than 26 μm, an arithmetic mean roughness Ra of 0.12 μm or more, a skewness Rsk of -1 to 1, and a kurtosis Rku of 2 to 4.

7. The glass plate according to claim 1, wherein the outermost surface of the region having the uneven structure on the first main surface side has a transmission haze of less than 15% as measured by a method in accordance with JIS K 7136 (2000).

8. The glass plate according to claim 7, wherein, at an outermost surface of the region having the uneven structure on the first main surface side, the surface roughness has an element mean length Rsm of a roughness curve of 26 μm or more, a skewness Rsk of -4 to -1.5, and a kurtosis Rku of 5 to 20.

9. The first main surface further has an anti-reflection film on at least a part thereof, the anti-reflection film covers at least a part of the uneven structure, the anti-reflection film has a laminated structure in which two or more low refractive index layers and high refractive index layers are alternately laminated, and the main components of the high refractive index layers are SiN, TiO ２ , Nb ２ O ５ , Ta ２ O ５ and ZrO ２ The glass plate according to claim 7, which is at least one selected from the group consisting of:

10. The glass plate according to any one of claims 1 to 9, having a printed layer on at least a portion of the second main surface.

11. The glass plate according to any one of claims 1 to 9, wherein the glass plate is a chemically strengthened glass.

12. The glass plate according to any one of claims 1 to 9, which is used as a cover glass for an in-vehicle display device.

13. An in-vehicle display device comprising a cover glass made of the glass plate according to claim 12 and a display panel.

14. A method for manufacturing a glass sheet according to any one of claims 1 to 9, wherein the glass sheet has a first main surface and a second main surface opposite to the first main surface, and the method includes forming a concave-convex structure on at least a portion of the first main surface.

15. The method for manufacturing a glass plate according to claim 14, wherein forming the uneven structure includes immersing the glass plate in a solution containing potassium fluoride and hydrogen fluoride, and then immersing the glass plate in a solution containing hydrogen fluoride, and further includes forming an anti-reflective film so as to cover at least a portion of the uneven structure.

16. The method for manufacturing a glass plate according to claim 14, wherein forming the uneven structure includes spraying a slurry onto the first main surface of the glass plate to roughen it, and then immersing the glass plate in a solution containing hydrogen fluoride to etch it.

17. The method for manufacturing a glass plate according to claim 16, wherein the spray angle of the slurry is 70° or less with respect to the first main surface.

18. The method for manufacturing a glass plate according to claim 16, wherein forming the uneven structure includes immersing the glass plate in a solution containing potassium fluoride and hydrogen fluoride, and then immersing the glass plate in a solution containing hydrogen fluoride, and further includes forming an anti-reflective film so as to cover at least a portion of the uneven structure.

19. A method for selecting a glass sheet according to any one of claims 1 to 9.

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