Display device

Abstract

The display device according to the present invention is provided with: a display panel; and a cover member disposed on the display panel. The cover member includes: a glass sheet that has been subjected to chemical strengthening and that has a first surface, and a second surface the depth of a compressive stress layer (dol) of which is greater than that of the first surface; and an optical layer that is layered on the second surface of the glass sheet and that faces outward.

Description

[Technical field]

[0001] The present invention relates to a display device and a cover member provided thereon. [Background technology]

[0002] Patent Document 1 discloses an in-vehicle display device, in which a cover member is fixed to the surface of a display panel, thereby protecting the display panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 208995 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the cover member is provided to protect the display panel, it is necessary to increase its strength, but for example, in the event of an accident, the driver or a person sitting in the passenger seat may be hit by the cover member, and therefore it is necessary to protect the driver, etc. The present invention has been made to solve the above problem, and aims to provide a display device, a cover member provided thereon, and a manufacturing method for the cover member that can protect the driver, etc. from the impact when the driver, etc. hits it. [Means for solving the problem]

[0005] Item 1. A display panel, a cover member disposed on the display panel; Equipped with The cover member is A glass plate that has been chemically strengthened and has a first surface and a second surface having a compressive stress layer depth (dol) greater than that of the first surface; an optical layer laminated to a second surface of the glass plate and facing outward; A display device comprising:

[0006] Item 2. The display device according to item 1, wherein the glass plate is manufactured by a float process, and a tin oxide concentration on the first surface is higher than that on the second surface.

[0007] Item 3. The display device according to item 1 or 2, wherein the optical layer is an organic-inorganic composite film.

[0008] Item 4. The optical layer contains at least a matrix and particles, 4. The display device according to any one of items 1 to 3, wherein the surface of the optical layer opposite to the second surface is unevenly formed by the particles.

[0009] Item 5. The display device according to claim 4, wherein the optical layer includes a first region in which the particles are piled up in the thickness direction of the film, and a valley-shaped second region that surrounds the first region or is surrounded by the first region.

[0010] Item 6. The display device according to claim 5, wherein the first region is a plateau-shaped region.

[0011] Item 7. The display device according to claim 5 or 6, wherein the second region includes a portion where the particles are not piled up or where no particles are present.

[0012] Item 8. The display device according to any one of claims 5 to 7, wherein the width of the first region is 7.7 μm or more, and the width of the second region is 7 μm or more.

[0013] Item 9. The display device according to any one of claims 5 to 7, wherein the width of the first region is 10 μm or more, and the width of the second region is 10 μm or more.

[0014] Item 10. The grains are substantially composed of tabular grains, the tabular grains have a thickness in the range of 0.3 nm to 3 nm and an average diameter of the main faces in the range of 10 nm to 1000 nm; Item 5. The display device according to item 4, wherein the major surfaces of the tabular grains are arranged approximately parallel to the second surface of the glass plate.

[0015] Item 11. The display device according to item 4, wherein the optical layer has an area where the particles are piled up in a thickness direction of the optical layer, and an area where the particles are not piled up or where no particles are present.

[0016] Item 12. The display device according to item 11, wherein a difference between a highest point and a lowest point of the optical layer measured from the second surface of the glass plate is three times or more the average particle size of the particles.

[0017] Item 13. The display device according to item 11 or 12, wherein Smr1 as defined by ISO25178 is 10 to 30%.

[0018] Item 14. The display device according to any one of items 11 to 13, wherein a surface height BH20 at a load area ratio of 20% as defined in ISO25178 is in the range of 0.04 μm to 0.5 μm.

[0019] Item 15. The display device according to any one of claims 11 to 14, wherein a surface height BH80 at a load area ratio of 80% as defined by ISO25178 is in the range of -0.3 µm to 0 µm.

[0020] Item 16. The display device according to any one of items 1 to 15, wherein Rsm of the surface of the optical layer is greater than 0 μm and is 35 μm or less. Here, the Rsm is the average length of the roughness curve element defined in JIS B0601:2001.

[0021] Item 17. The display device according to any one of items 1 to 16, wherein the surface of the optical layer has an Ra in the range of 20 nm to 120 nm. Here, the above Ra is the arithmetic mean roughness of the roughness curve defined in JIS B0601:2001.

[0022] Item 18. The display device according to any one of items 1 to 17, wherein the second surface of the glass plate has an Ra of 10 nm or less. Here, the above Ra is the arithmetic mean roughness of the roughness curve defined in JIS B0601:2001.

[0023] Item 19. The display device according to any one of items 1 to 18, wherein the matrix is ​​mainly made of silicon oxide.

[0024] Item 20. The display device according to any one of items 1 to 19, wherein the glass plate has a thickness of 0.5 to 3 mm.

[0025] Item 21. A cover member provided in a display device having a display panel, A glass plate manufactured by a float process and having a first surface and a second surface having a higher tin oxide concentration than the first surface; an optical layer laminated to a second surface of the glass plate and facing outward; A cover member comprising: Effect of the Invention

[0026] According to the present invention, when a driver or the like is hit, the driver or the like can be protected from the impact. [Brief description of the drawings]

[0027] [Figure 1] 1 is a plan view showing an embodiment of a display device according to the present invention. [Diagram 2] 2 is a partial cross-sectional view of a cover member provided in the display device of FIG. 1. [Diagram 3] FIG. 2 is a perspective view showing an example of particles contained in the first anti-glare film. [Figure 4] 4 is a cross-sectional view of a cover member on which a second anti-glare film is laminated. FIG. [Diagram 5] 4 is a cross-sectional view of a cover member on which a second anti-glare film is laminated. FIG. [Figure 6] 13 is a cross-sectional view of a cover member on which a third anti-glare film is laminated. FIG. [Figure 7] 13 is a cross-sectional view of a cover member on which a third anti-glare film is laminated. FIG. [Figure 8]4 is a cross-sectional view that illustrates a cross section of a convex portion of a film of a cover member on which a third anti-glare film is laminated. FIG. [Figure 9] FIG. 2 is a plan view showing an example of a shielding layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment in which the display device according to the present invention is applied to an in-vehicle display device will be described with reference to the drawings. Fig. 1 is a cross-sectional view of the display device. Examples of the in-vehicle display device include a car navigation system and a display device that displays various instruments and operation panels.

[0029] <1. Overview of the display device> 1, the display device according to this embodiment includes a housing 4 having an opening, a display panel 500 and a backlight unit 6 housed in the housing 4, and a cover member 100 that covers the opening of the housing 4. Each member will be described in detail below.

[0030] <2. Housing> The housing 4 has a rectangular bottom wall 41 and a side wall 42 rising from the periphery of the side wall 41, and the above-mentioned display panel 500 and backlight unit 6 are housed in the internal space surrounded by the bottom wall 41 and the side wall 42. The above-mentioned cover member 100 is attached so as to cover the opening formed by the upper end of the side wall 42. The material constituting the housing 4 is not particularly limited, and can be, for example, a resin material, a metal, or the like.

[0031] <3. Display panel and backlight unit> A known liquid crystal panel can be used as the display panel 500. The backlight unit 6 irradiates light toward the liquid crystal panel, and is, for example, a known one in which a diffusion sheet, a light guide plate, a light source such as an LED, a reflective sheet, and the like are laminated. Note that, in addition to a liquid crystal panel, for example, an organic EL panel, a plasma display panel, an electronic ink type panel, and the like can be adopted as the display panel 500. When a panel other than a liquid crystal panel is used as the display panel 500, a backlight unit is not necessary.

[0032] <4. Cover material> The cover member 100 includes a glass plate 10 having a first surface and a second surface, an adhesive layer 3 laminated on the first surface of the glass plate 10, and an optical layer 20 laminated on the second surface. The first surface of the glass plate 10 faces the display panel 500, and the second surface faces the outside of the display device, that is, the driver's side in this embodiment. This will be described in detail below.

[0033] <4-1. Glass plate> The glass plate 10 can be formed from, for example, general-purpose soda-lime glass, borosilicate glass, aluminosilicate glass, alkali-free glass, or other glass. The glass plate 10 can be formed by a float process. This manufacturing method can provide a glass plate 10 having a smooth surface. However, the glass plate 10 may have irregularities on the main surface, and may be, for example, patterned glass. Patterned glass can be formed by a manufacturing method called a roll-out method. Patterned glass produced by this manufacturing method usually has periodic irregularities in one direction along the main surface of the glass plate.

[0034] In the float process, molten glass is continuously fed onto a molten metal such as molten tin, and the molten glass is made to flow on the molten metal to form it into a strip shape. The glass formed in this way is called a glass ribbon.

[0035] The glass ribbon is cooled as it moves downstream, and is pulled up from the molten metal by rollers after being cooled and solidified. Then, the glass ribbon is transported to an annealing furnace by rollers, annealed, and then cut. In this manner, a float glass sheet is obtained. Here, the surface of the float glass sheet that was in contact with the molten metal is referred to as the bottom surface, and the opposite surface is referred to as the top surface. The bottom surface and the top surface may be unpolished. Since the bottom surface was in contact with the molten metal, when the molten metal is tin, the concentration of tin oxide contained in the bottom surface is greater than the concentration of tin oxide contained in the top surface. In this embodiment, the first surface of the glass sheet 10 is the bottom surface, and the second surface is the top surface.

[0036] The thickness of the glass plate 10 formed as described above is not particularly limited, but it is preferable that it is thin in order to reduce weight. For example, it is preferably 0.5 to 3 mm, and more preferably 0.6 to 2.5 mm. This is because if the glass plate 10 is too thin, the strength decreases, and if it is too thick, there is a risk of distortion occurring in the image viewed from the display panel 500 through the cover member 100. The surface roughness Ra of the second surface of the glass plate 10 is preferably 10 nm or less, more preferably 5 nm or less, even more preferably 2 nm or less, and particularly preferably 1 nm or less. In this way, when the optical layer 20 is an antiglare film, as described later, the antiglare effect is prominent.

[0037] The glass plate 10 may be a flat plate, but may also be a curved plate. In particular, when the image display surface of the display panel 500 to be combined is a non-flat surface such as a curved surface, it is preferable that the glass plate 10 has a main surface of a non-flat shape that matches it. In this case, the glass plate 10 may be curved so that the entire glass plate 10 has a certain curvature, or may be curved locally. The main surfaces (first surface and second surface) of the glass plate 10 may be configured, for example, by a plurality of flat surfaces connected to each other by curved surfaces. The radius of curvature of the glass plate 10 is, for example, 5000 mm or less. This radius of curvature is, for example, 10 mm or more, but may be even smaller, for example, 1 mm or more, especially in the part that is locally curved. Note that the term "main surface" used in this specification refers to the front and back surfaces excluding the side surfaces.

[0038] The optical layer 20 may be formed so as to cover the entire surface or a part of the second surface of the glass plate 10. In the latter case, the optical layer 20 is preferably formed on at least a portion of the second surface that covers the image display surface of the display panel 500.

[0039] The glass plate 10 is also chemically strengthened. This will be described in detail. The method of chemical strengthening is not particularly limited, but for example, the glass plate 10 containing sodium is brought into contact with a molten salt containing a monovalent cation, preferably a potassium ion, having an ionic radius larger than that of a sodium ion, and an ion exchange process is performed to replace the sodium ion in the glass plate 1 with the monovalent cation, thereby chemically strengthening the glass plate 1. As a result, a compressive stress layer in which compressive stress is applied to the surface is formed.

[0040] A typical example of the molten salt is potassium nitrate. Although a mixed molten salt of potassium nitrate and sodium nitrate can be used, it is preferable to use a molten salt of potassium nitrate alone, since it is difficult to control the concentration of the mixed molten salt.

[0041] The surface compressive stress and the compressive stress layer depth in the glass plate 10 can be controlled not only by the glass composition but also by the temperature and treatment time of the molten salt in the ion exchange treatment. The treatment temperature in the ion exchange treatment can be, for example, 360 to 460°C. For the glass plate 10 having the above-mentioned composition for chemical strengthening, the treatment temperature is preferably high, and can be, for example, 400 to 460°C.

[0042] Incidentally, the glass plate 10 of the present embodiment is manufactured by the float method as described above, so that the tin oxide concentration of the top surface is smaller than that of the bottom surface. Therefore, when the above-mentioned chemical strengthening is performed, the compressive stress layer depth (dol) of the top surface becomes larger than that of the bottom surface. The compressive stress layer depth depends on conditions such as the composition and temperature of the glass plate, but the deeper the compressive stress layer depth, the smaller the compressive stress tends to be. Therefore, the surface compressive stress of the top surface, that is, the second surface of the glass plate 10, becomes smaller than that of the first surface. Specifically, when the top surface and the bottom surface of the glass plate 10 are chemically strengthened under the same conditions, the compressive stress layer depth of the second surface becomes larger by about 1 to 10 μm than that of the first surface, and thus the surface compressive stress of the second surface becomes smaller by about 30 to 180 MPa than that of the first surface. The compressive stress layer depth can be measured, for example, by a surface stress meter.

[0043] For example, when the top and bottom surfaces of the glass plate 10 are chemically strengthened under the same conditions, the inventors have obtained the following test results. That is, the compressive stress layer depth on the top surface is 10 to 20 μm, and the surface compressive stress at this time is 650 to 800 MPa. On the other hand, the compressive stress layer depth on the bottom surface is 9 to 19 μm, and the surface compressive stress at this time is 680 to 830 MPa. Therefore, when the top and bottom surfaces of the glass plate are chemically strengthened under the same conditions, the compressive stress depth on the top surface is deeper than that on the bottom surface, and correspondingly, the surface compressive stress on the top surface is smaller than that on the bottom surface. Therefore, when an impact is applied to the glass plate, the top surface is more likely to break than the bottom surface.

[0044] <4-2.Adhesive layer> The adhesive layer 3 may be any adhesive layer capable of fixing the glass plate 10 to the display panel 500 with sufficient strength. Specifically, an adhesive layer such as a resin obtained by copolymerizing acrylic, rubber, and methacrylic monomers with acrylic monomers having tackiness at room temperature and setting the desired glass transition temperature can be used. As the acrylic monomer, methyl acrylate, ethyl acrylate, butyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, etc. can be applied, and as the methacrylic monomer, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, stearyl methacrylate, etc. can be applied. In addition, when applying by heat lamination, an organic material that softens at the lamination temperature may be used. For example, in the case of a resin obtained by copolymerizing methacrylic and acrylic monomers, the glass transition temperature can be adjusted by changing the compounding ratio of each monomer. An ultraviolet absorbing agent may be contained in the adhesive layer 71.

[0045] The thickness of the adhesive layer 3 can be, for example, 10 to 500 μm, and is preferably 20 to 350 μm. In particular, when the thickness of the adhesive layer 3 is small, the distance from the display panel 500 to the outermost surface of the cover member 100 becomes small, and as a result, the image on the display panel 500 can be clearly viewed. On the other hand, when the thickness of the adhesive layer 3 is too small, the fixing strength between the glass plate and the display panel 500 decreases, which is not preferable.

[0046] Moreover, it is preferable that the refractive index of the adhesive layer 3 is larger than the refractive index of air and smaller than the refractive index of the glass plate 10. This can suppress distortion of the image displayed on the display panel.

[0047] <4-3. Optical layer> Next, the optical layer will be described. Three types of anti-glare films will be described below as an example of the optical layer. In the following description, "substantially parallel" means that the angle between the two surfaces is 30° or less, further 20° or less, and particularly 10° or less. Furthermore, "main component" means a component whose content is 50% or more, further 80% or more by mass. Furthermore, "substantially composed" means that the content is 80% or more, further 90% or more, and particularly 95% or more by mass. The "main surface" of a tabular particle refers to a pair of front and back surfaces of the tabular particle, similar to the main surface of the above-mentioned glass plate. The definition of "plateau-like" will be described later with reference to FIG. 8.

[0048] <4-3-1. First anti-glare film> First, the first anti-glare film 20 will be described with reference to FIG. 2. FIG. 2 is a partial cross-sectional view of a glass plate on which an anti-glare film is laminated. In the example of FIG. 2, the anti-glare film 20 is formed directly on the second surface of the glass plate 10, but another film may be interposed between the glass plate 10 and the anti-glare film 20. The anti-glare film 20 includes particles 1 and a matrix 2. The anti-glare film 20 may include voids. The voids may be present in the matrix 2 or in contact with the particles 1 and the matrix 2.

[0049] <4-3-1-1. Particles> The particle 1 may be a tabular particle. The particle 1 may be substantially composed of tabular particles. However, a part of the particle 1 may have a shape other than a tabular shape, for example, a spherical shape, but the particle 1 may not include spherical particles and may be composed only of tabular particles. FIG. 3 shows an example of the particle 1, which is a tabular particle. The particle 1 has a pair of main surfaces 1s. The pair of main surfaces 1s are approximately parallel to each other. The main surface 1s may be substantially flat. However, the main surface 1s may have steps or minute irregularities. Note that a particle formed by linking spherical silicon oxide particles has an outer shape that is chain-like and not flat, and does not fall under the category of a tabular particle.

[0050] The thickness 1t of the particle 1 corresponds to the distance between a pair of main surfaces 1s and is in the range of 0.3 nm to 3 nm. The thickness 1t is preferably 0.5 nm or more, more preferably 0.7 nm or more, and is preferably 2 nm or less, more preferably 1.5 nm or less. When the thickness 1t varies depending on the location, the thickness 1t may be determined as the average of the maximum thickness and the minimum thickness.

[0051] The average diameter d of the main surface 1s of the particle 1 is in the range of 10 nm to 1000 nm. The average diameter d of the main surface is preferably 20 nm or more, more preferably 30 nm or more. The average diameter d is preferably 700 nm or less, more preferably 500 nm or less. The average diameter d of the main surface 1s can be determined by averaging the minimum and maximum diameters passing through the center of gravity of the main surface 1s.

[0052] The average aspect ratio of the particles 1 can be calculated by d / t. The average aspect ratio is not particularly limited, but is preferably 30 or more, more preferably 50 or more. The average aspect ratio may be 1000 or less, more preferably 700 or less.

[0053] The particle 1 may be a phyllosilicate mineral particle. The phyllosilicate mineral contained in the phyllosilicate mineral particle is also called a layered silicate mineral. Examples of phyllosilicate minerals include kaolinite, dickite, nacrite, halloysite, and other kaolin minerals; serpentines such as chrysotile, lizardite, and amesite; dioctahedral smectites such as montmorillonite and beidellite; trioctahedral smectites such as saponite, hectorite, and sauconite; dioctahedral micas such as muscovite, paragonite, illite, and celadonite; trioctahedral micas such as phlogopite, anite, and lepidolite; dioctahedral brittle micas such as margarite; trioctahedral brittle micas such as clintite and annandite; dioctahedral chlorites such as donbasite; 2-3 octahedral chlorites such as cookeite and sudoite; trioctahedral chlorites such as clinochlore and chamosite; pyrophyllite, talc, dioctahedral vermiculite, and trioctahedral vermiculite. The phyllosilicate mineral particles preferably contain a mineral belonging to smectite, kaolin, or talc. As a mineral belonging to smectite, montmorillonite is suitable. Note that montmorillonite belongs to the monoclinic system, kaolin belongs to the triclinic system, and talc belongs to the monoclinic or triclinic system.

[0054] In the anti-glare film 20, the particles 1 are arranged such that the main surface 1s is approximately parallel to the second surface of the glass plate 10. If 80% or more, further 85% or more, and particularly 90% or more of the particles 1 are arranged approximately parallel by number, the particles 1 are considered to be arranged approximately parallel as a whole even if the remainder are not arranged approximately parallel. When judging this, it is desirable to confirm the arrangement of 30, preferably 50, tabular particles.

[0055] When the particles 1 are phyllosilicate particles, the crystal plane of the phyllosilicate oriented along the second surface of the glass sheet 10 may be the (001) plane. Such plane orientation can be confirmed by X-ray diffraction analysis.

[0056] <4-3-1-2. Matrix> The matrix 2 preferably contains silicon oxide, which is an oxide of Si, and is mainly composed of silicon oxide. The matrix 2 mainly composed of silicon oxide is suitable for lowering the refractive index of the film and suppressing the reflectance of the film. The matrix 2 may contain a component other than silicon oxide, or may contain a component partially containing silicon oxide.

[0057] A component partially containing silicon oxide is, for example, a component that includes a portion composed of silicon atoms and oxygen atoms, and an atom other than both atoms, a functional group, or the like is bonded to the silicon atom or oxygen atom of this portion. Examples of atoms other than silicon atoms and oxygen atoms include, for example, nitrogen atoms, carbon atoms, hydrogen atoms, and metal elements described in the next paragraph. Examples of functional groups include, for example, organic groups described as R in the next paragraph. Strictly speaking, such components are not silicon oxide in that they are not composed only of silicon atoms and oxygen atoms. However, in describing the characteristics of the matrix 2, it is appropriate to treat the silicon oxide portion composed of silicon atoms and oxygen atoms as "silicon oxide", and this is consistent with the conventions in the field. In this specification, the silicon oxide portion is also treated as silicon oxide. As is clear from the above explanation, the atomic ratio of silicon atoms to oxygen atoms in silicon oxide does not have to be stoichiometric (1:2).

[0058] The matrix 2 may contain a metal oxide other than silicon oxide, specifically a metal oxide component or a metal oxide portion containing elements other than silicon. The metal oxide that the matrix 2 may contain is not particularly limited, but may be, for example, an oxide of at least one metal element selected from the group consisting of Ti, Zr, Ta, Nb, Nd, La, Ce, and Sn. The matrix 2 may contain an inorganic compound component other than an oxide, such as a nitride, a carbide, or a halide, or may contain an organic compound component.

[0059] Metal oxides such as silicon oxide can be formed from hydrolyzable organometallic compounds. Examples of hydrolyzable silicon compounds include compounds represented by formula (1): Rn SiY 4-n (1) R is an organic group containing at least one selected from an alkyl group, a vinyl group, an epoxy group, a styryl group, a methacryloyl group, and an acryloyl group. Y is at least one hydrolyzable organic group selected from an alkoxy group, an acetoxy group, an alkenyloxy group, and an amino group, or a halogen atom. The halogen atom is preferably Cl. n is an integer from 0 to 3, and is preferably 0 or 1.

[0060] R is preferably an alkyl group, for example an alkyl group having 1 to 3 carbon atoms, particularly a methyl group. Y is preferably an alkoxy group, for example an alkoxy group having 1 to 4 carbon atoms, particularly a methoxy group and an ethoxy group. Two or more compounds represented by the above formula may be used in combination. Such a combination may include, for example, a combination of a tetraalkoxysilane in which n is 0 and a monoalkyltrialkoxysilane in which n is 1.

[0061] After hydrolysis and polycondensation, the compound represented by formula (1) forms a network structure in which silicon atoms are bonded to each other via oxygen atoms, and in this structure, the organic group represented by R is included in the network structure in a state in which it is directly bonded to the silicon atom.

[0062] <4-3-1-3. Physical properties of the first anti-glare film> The ratio of particles 1 to matrix 2 in anti-glare film 20 is, on a mass basis, for example, 0.05 to 10, further 0.05 to 7, and preferably 0.05 to 5. The volume ratio of voids in anti-glare film 20 is not particularly limited, but may be 10% or more, further 10 to 20%. However, voids may not necessarily exist.

[0063] The thickness of the anti-glare film 20 is not particularly limited, but from the viewpoint of easily obtaining suitable anti-glare properties, for example, 50 nm to 1000 nm, more preferably 100 nm to 700 nm, and particularly preferably 100 nm to 500 nm. In order to orient the main faces of the tabular particles so as to be approximately parallel to the substrate, it is preferable that the thickness of the anti-glare film 20 is equal to or less than the above-mentioned upper limit. In a thick film, the tendency of the tabular particles to be randomly oriented becomes stronger.

[0064] It is preferable that the surface 20s of the anti-glare film 20 has minute irregularities. This is expected to provide a higher anti-glare effect. However, the development of the irregularities on the surface 20s is suppressed by the orientation of the particles 1 along the second surface of the glass plate 10. The surface roughness of the surface 20s of the anti-glare film 20 is expressed by Ra and is 20 nm to 120 nm, further 30 nm to 110 nm, and preferably 40 nm to 100 nm. Ra is the arithmetic mean roughness of the roughness curve defined by JIS B0601:2001. For example, if the particles are randomly oriented, the surface roughness Ra will be greater than the above-mentioned range.

[0065] The Rsm of the surface 20s is more than 0 μm and not more than 35 μm, more preferably 1 μm to 30 μm, and even more preferably 2 μm to 20 μm. Rsm is the average length of the roughness curve element defined by JIS B0601:2001. A not too large Rsm is suitable for suppressing so-called sparkle.

[0066] Sparkle is a bright spot that occurs depending on the relationship between the minute irregularities for imparting anti-glare function and the pixel size of the display panel. Sparkle is observed as an irregular fluctuation of light accompanying the change in the relative position between the display device and the user's viewpoint. Sparkle has become more evident as display devices become more highly fine. The anti-glare film 20 having Ra and Rsm within the above-mentioned ranges is particularly suitable for suppressing sparkle while reducing gloss and haze in a balanced manner.

[0067] <4-3-1-4. Optical properties of cover material> The gloss can be evaluated by the specular gloss. The 60° specular gloss of the glass plate 10 is, for example, 60 to 130%, further 70 to 120%, particularly 80 to 110%, or 85 to 100%. These specular gloss values ​​are values ​​measured on the surface 10s on which the anti-glare film 20 is formed. The haze of the glass plate 10 is, for example, 20% or less, further 15% or less, particularly 10% or less, and may be 1 to 8%, further 1 to 6%, or particularly 1 to 5% in some cases.

[0068] Between the 60° specular gloss G and the haze H (%), it is preferable that the relational formula (a) is satisfied, more preferably that the relational formula (b) is satisfied, and even more preferably that the relational formula (c) is satisfied. G and H may satisfy the relational formula (d). H≦-0.2G+25 (a) H≦-0.2G+24.5 (b) H≦-0.2G+24 (c) H≦-0.15G+18 (d)

[0069] The gloss can be measured according to "Method 3 (60-degree specular gloss)" of "Specular gloss measurement method" of JIS Z8741-1997, and the haze can be measured according to JIS K7136:2000.

[0070] <4-3-2. Second anti-glare film> Next, the second anti-glare film will be described with reference to Figs. 4 and 5. Figs. 4 and 5 are partial cross-sectional views of a glass plate on which the second anti-glare film is laminated. In Figs. 4 and 5, the anti-glare films 30 and 40 are directly formed on the second surface of the glass plate 10, but another film may be interposed between the glass plate 10 and the anti-glare films 30 and 40. These anti-glare films 30 and 40 contain particles 5 and a matrix 2. The anti-glare films 30 and 40 may contain voids. The voids may be present in the matrix 2 or in contact with the particles 5 and the matrix 2.

[0071] In the anti-glare film 30, the particles 5 are piled up in the thickness direction of the film in all regions, whereas in the anti-glare film 40, there are regions 40a where the particles 5 are piled up in the thickness direction of the film, and regions 40b where the particles 5 are not piled up in the same direction or where no particles 5 are present. Region 40b may not be a region where the particles 5 are not piled up in the same direction or where no particles 5 are present, but may be a region having a surface 40s that is approximately parallel to the second surface of the glass plate 10 and where no particles 5 are exposed. Region 40b may be, for example, a region having a thickness of 0.25 μm. 2 Above that, another 0.5μm 2 Above 1μm 2 In at least a part of region 40a of anti-glare films 30 and 40, particles 5 are piled up to a height of 5 times or more, or even 7 times or more the average particle size of particles 5.

[0072] <4-3-2-1. Particles> The shape of the particle 5 is not particularly limited, but is preferably spherical. The particle 5 may be substantially composed of spherical particles. However, a part of the particle 5 may have a shape other than spherical, for example, a plate-like shape. The particle 5 may be composed only of spherical particles. Here, the spherical particle refers to a particle whose surface is composed of a curved surface, and whose ratio of the longest diameter to the shortest diameter passing through the center of gravity is 1 to 1.8, particularly 1 to 1.5. The average particle size of the spherical particles may be 5 nm to 200 nm, further 10 nm to 100 nm, particularly 20 nm to 60 nm. The average particle size of the spherical particles is determined by the average of the individual particle sizes, specifically the average value of the shortest diameter and the longest diameter described above, and it is desirable to carry out the measurement based on an SEM image for 30 particles, preferably 50 particles.

[0073] The preferred ranges of the thickness t, the average diameter d of the main surface, and the aspect ratio d / t of the tabular grains which may be contained in some of the grains 5 are the same as those of the first anti-glare film.

[0074] The material constituting the particles 5 is not particularly limited, but preferably contains a metal oxide, particularly silicon oxide. However, the metal oxide may contain an oxide of at least one metal element selected from the group consisting of Ti, Zr, Ta, Nb, Nd, La, Ce, and Sn.

[0075] The particles 5 can be supplied to the anti-glare films 30 and 40 from a dispersion of the particles 5. In this case, it is preferable to use a dispersion in which the particles 5 are dispersed individually and independently. Compared to a dispersion in which the particles are linked in chains, the use of a dispersion in which the particles are not aggregated is suitable for realizing a desired aggregation state of the particles in the anti-glare films 30 and 40. This is because the particles 5 that are independent of each other are likely to move with the evaporation of the liquid such as the dispersion medium, and are likely to be in an aggregated state suitable for achieving good properties in the film.

[0076] <4-3-2-2. Matrix> The matrix 2 is the same as the first anti-glare film 20 described above. However, in the second anti-glare films 30 and 40, the matrix 2 preferably contains nitrogen atoms. The nitrogen atoms are preferably contained as part of an organic compound component or a functional group, particularly a nitrogen-atom-containing functional group. The nitrogen-atom-containing functional group is preferably an amino group. The nitrogen atoms can be part of a highly reactive functional group, particularly in raw materials for forming a matrix mainly composed of a metal oxide such as silicon oxide. Such functional groups can promote the aggregation of the particles 5 during film formation and can play a role in making the aggregation state of the particles 5 into a desirable form.

[0077] Metal oxides such as silicon oxide can be formed from hydrolyzable organometallic compounds. Examples of hydrolyzable silicon compounds include the compounds shown in formula (1).

[0078] Nitrogen atoms can also be provided to the anti-glare films 30 and 40 from a compound containing silicon atoms, specifically, an amino group-containing silane coupling agent. This compound can be represented, for example, by formula (2). A k B m SiY4-k-m (2)

[0079] A is an organic group containing an amino group. The amino group may be any of primary, secondary and tertiary amino groups. A is, for example, an amino group-containing hydrocarbon, preferably an alkyl group or alkenyl group having some atoms substituted with an amino group, more preferably an alkyl group or alkenyl group having a hydrogen atom substituted with an amino group, and particularly preferably an alkyl group or alkenyl group having an amino group at the end. The alkyl group and the alkenyl group may be linear or branched. A is preferably an ω-aminoalkyl group having an amino group at the end of the alkyl group, and an N-ω'-(aminoalkyl)-ω-aminoalkyl group in which the hydrogen atom of the amino group is substituted with another aminoalkyl group. A preferably contains a carbon atom as an atom connected to a silicon atom. In this case, a hydrocarbon group such as an alkyl group or an alkenyl group may be present between the nitrogen atom and the silicon atom. In other words, the nitrogen atom may be bonded to a silicon atom constituting silicon oxide via a hydrocarbon group. Particularly preferred A is a γ-aminopropyl group or an N-(2-aminoethyl)-3-aminopropyl group.

[0080] B may be the organic group described above as R, or may be an alkyl group or an alkenyl group. The alkyl group or alkenyl group may have a branch, and some of the hydrogen atoms may be substituted. B is preferably an unsubstituted alkyl group, more preferably a linear alkyl group, the carbon chain of which has 1 to 3 carbon atoms, and even more preferably a methyl group. Y is as described above. k is an integer of 1 to 3, m is an integer of 0 to 2, and k+m is an integer of 1 to 3. k is 1, and m is 0 or 1. When A is a γ-aminopropyl group, k=1 and m=0 are preferable, and when A is an N-(2-aminoethyl)-3-aminopropyl group, k=1 and m=0 or 1 are preferable.

[0081] After hydrolysis and polycondensation, the compound represented by formula (2) forms a network structure in which silicon atoms are bonded to each other via oxygen atoms. When used together with the compound represented by formula (1), the compound represented by formula (2) forms part of the network structure. In this structure, the organic group represented by A is included in the state of being directly bonded to the silicon atom.

[0082] The organic group represented by A is thought to attract particles and promote particle aggregation during the process in which the solvent in the coating liquid evaporates.

[0083] The first and second anti-glare films 20, 30, 40 having the above-mentioned compositions can be said to be organic-inorganic composite films.

[0084] <4-3-2-3. Physical properties of the second anti-glare film> The ratio of particles 5 to matrix 2 in the anti-glare films 30 and 40, the film thickness of the anti-glare films 30 and 40, the Ra of the surfaces 30s and 40s, and the Rsm of the surfaces 30s and 40s are not particularly limited, but may be in the same range as that of the first anti-glare film 20 described above.

[0085] In anti-glare films 30 and 40, particles 5 aggregate and overlap locally to increase the height of the film in those areas, while in other areas the particles 5 do not overlap and the film is locally thinner. The difference between the highest and lowest points of anti-glare films 30 and 40 measured from the second surface of glass plate 10 may be three or more times, or even four or more times, the average particle size of particles 5.

[0086] In region 40b of anti-glare film 40, the particles are not stacked in the thickness direction of the film, or no particles are present. In the latter case, in region 40b, film 40 may be composed of only matrix 2. The ratio of region 40b to the area of ​​the region where anti-glare film 40 is formed may be, for example, 5 to 90%, further 10 to 70%, and particularly 20 to 50%.

[0087] <4-3-2-4. Optical properties of cover material> The gloss can be evaluated by the specular gloss. The 60° specular gloss of the glass plate 10 is, for example, 60 to 130%, further 70 to 120%, particularly 80 to 110%, or 85 to 100%. These specular gloss values ​​are values ​​measured on the second surface of the glass plate on which the anti-glare films 30, 40 are formed. The haze of the glass plate 10 is, for example, 20% or less, further 15% or less, particularly 10% or less, and may be 1 to 8%, further 1 to 6%, or particularly 1 to 5% in some cases.

[0088] Between the 60° specular gloss G and the haze ratio H (%), it is preferable that the relationship (a) holds, and it is more preferable that the relationship (b) holds. H≦-0.2G+25 (a) H≦-0.2G+24.5 (b)

[0089] The Japanese Industrial Standards numbers referenced for the measurements of gloss and haze are as described above.

[0090] <4-3-2-5. Parameters related to load curve> The cover glasses 200 and 300 on which the second anti-glare film is laminated may have the following characteristics with respect to parameters related to the load curve in accordance with ISO25178. As specified in ISO25178, the load curve is a percentage obtained by accumulating the frequency at a certain height from the high side, with the total number of all height data being 100. Based on the load curve, the area load ratio at a certain height C is given as Smr(C). The line with the smallest slope among the lines where the difference in the Smr values ​​at two points of a certain height is 40% is taken as an equivalent line, and the difference in height between the equivalent line when the area load ratio is 0% and 100% is the level difference Sk of the core part. The area load ratio that separates the core part from the protruding peak part that is equal to or higher than the height of the core part is Smr1, and conversely, the area load ratio that separates the core part from the protruding valley part that is equal to or lower than the height of the core part is Smr2. The surface heights at the area load ratios of 20, 40, 60, and 80% are BH20, BH40, BH60, and BH80.

[0091] Smr1 may be 1 to 40%, further 3 to 35%, and in some cases 10 to 30%. BH20 is, for example, 0.04 μm to 0.5 μm, further 0.06 μm to 0.5 μm, and preferably 0.12 μm to 0.3 μm. BH80 is, for example, −0.3 μm to 0 μm, further −0.3 μm to −0.05 μm, and preferably −0.25 μm to −0.12 μm.

[0092] <4-3-3. The third anti-glare film> Next, the third anti-glare film will be described with reference to Figs. 6 and 7. Fig. 6 is a partial cross-sectional view of a glass plate on which the third anti-glare film is laminated, and Fig. 7 is a partial cross-sectional view showing another example of a glass plate on which the third anti-glare film is laminated. As shown in Figs. 6 and 7, the cover members 400 and 500 include a glass plate 10 and anti-glare films 50 and 60 provided on the glass plate 10. In Figs. 6 and 7, the anti-glare films 50 and 60 are directly formed on the main surface 10s of the glass plate 10, but another film may be interposed between the glass plate 10 and the anti-glare films 50 and 60. The anti-glare films 50 and 60 include particles 5 and a matrix 2. The anti-glare films 50 and 60 may include voids. The voids may be present in the matrix 2 or in contact with the particles 5 and the matrix 2.

[0093] The anti-glare films 50 and 60 have first regions 50p and 60p and second regions 50v and 60v. In the first regions 50p and 60p, the particles 5 are stacked in the thickness direction of the anti-glare films 50 and 60. When the anti-glare films 50 and 60 are observed from the surface side along the thickness direction, the second regions 50v and 60v surround the first regions 50p and 60p. However, the second regions 50v and 60v may be surrounded by the first regions 50p and 60p. For example, the first regions 50p and 60p and the second regions 50v and 60v are interposed between a plurality of regions that are spaced apart from each other. This structure is sometimes called a sea-island structure. The second regions 50v and 60v are valley-shaped regions whose surfaces are recessed from the surrounding first regions. Therefore, the islands of the sea-island structure protrude from the sea when the islands are the first regions 50p and 60p, and are recessed from the sea when the islands are the second regions 50v and 60v. The second regions 50v and 60v have fewer piled-up particles 5 than the first regions 50p and 60p. The second regions 50v and 60v may include a portion 50t where the particles 5 are piled up (see FIG. 6). The second regions 50v and 60v may include a portion where the particles 5 are not piled up or where the particles 5 are not present (see FIG. 6 and FIG. 7). At least a part of the second regions 50v and 60v may be composed of a portion where the particles 5 are not piled up or where the particles 5 are not present. At least a part of the first regions 50p and 60p, or even 50% or more by number, or in some cases the entire region, may be a plateau region.

[0094] "Plateau-like" means that the tops of the convex portions of the anti-glare films 50 and 60 look plateau-like when the film is observed by SEM or the like, but strictly speaking, L2 / L1≧0.75, particularly L2 / L1≧0.8, is satisfied in the cross section of the film. Here, as shown in FIG. 8, L1 is the length of a portion equivalent to 50% of the height H of each convex portion, and L2 is the length of a portion equivalent to 70% of the height H, preferably 75% of the height H. As shown in FIG. 8, for one L1, L2 may exist divided into two or more portions. In this case, L2 is determined by the total length of the two or more portions.

[0095] The boundaries 50b and 60b between the first regions 50p and 60p and the second regions 50v and 60v can be determined by the average thickness T of the anti-glare films 50 and 60 (see FIG. 7). The average thickness T can be measured using a laser microscope, as described below. The width Wp of the first regions 50p and 60p and the width Wv of the second regions 50v and 60v are determined by the distance between the boundaries 50b and 60b.

[0096] The width Wp may be 5 μm or more, further 7.7 μm or more, preferably 10 μm or more. The width Wv may be 3.5 μm or more, 7 μm or more, preferably 10 μm or more. When the width Wp is large, the visible light incident on the antiglare film is easily transmitted directly, so the haze ratio tends to be low. When the width Wv is large, the visible light incident on the antiglare film is moderately scattered, so the gloss tends to be low. A film in which the width Wp and the width Wv are both 10 μm or more is particularly suitable for achieving both a low haze ratio and gloss.

[0097] The first regions 50p and 60p and the second regions 50v and 60v are each, for example, 0.25 μm 2 Above that, another 0.5μm 2 Above 1μm 2 More than 5μm in some cases 2 Above that, another 10μm 2 The area may extend over the above range.

[0098] The anti-glare films 50 and 60 include first regions 50p and 60p and second regions 50v and 60v. The ratio of the area of ​​the region where the anti-glare film 40 is formed to the area of ​​the second regions 50v and 60v may be, for example, 5 to 90%, further 10 to 70%, and particularly 20 to 50%. The anti-glare films 50 and 60 may be composed of only the first regions 50p and 60p and the second regions 50v and 60v.

[0099] <4-3-3-1. Particles> The particles 5 are as described in the second anti-glare film.

[0100] <4-3-3-2. Matrix> The matrix 2 is as described for the first and second anti-glare films. However, unlike the second anti-glare film, in the third anti-glare film, there is little need to promote the aggregation of the particles 5 by adding nitrogen atoms. Therefore, it is preferable that the metal oxide such as silicon oxide forming the matrix 2 is formed from a hydrolyzable organometallic compound, in particular, the compound represented by formula (1). The matrix 2 may be substantially composed of silicon oxide.

[0101] <4-3-3-3. Physical properties of the third anti-glare film> In the anti-glare films 50 and 60, the ratio of particles 5 to matrix 2, the film thickness, Ra of surfaces 50s and 60s, and Rsm of surfaces 50s and 60s are not particularly limited, and may be in the ranges described for the first and second anti-glare films. The difference between the highest and lowest points of the anti-glare films 50 and 60 measured from the main surface 10s of the glass plate 10 may be three or more times, or even four or more times, the average particle size of the particles 5.

[0102] <4-3-3-4. Optical properties of cover material> The gloss can be evaluated by the specular gloss. The 60° specular gloss of the glass plate 10 is, for example, 60 to 130%, further 70 to 120%, particularly 80 to 110%, or 85 to 100%. These specular gloss values ​​are values ​​measured for the surface 10s on which the anti-glare films 50 and 60 are formed. The haze of the glass plate 10 is, for example, 20% or less, further 15% or less, particularly 10% or less, and may be 1 to 8%, further 1 to 6%, or particularly 1 to 5% in some cases.

[0103] Between the 60° specular gloss G and the haze H (%), the relational formula (a) is preferably satisfied, the relational formula (b) is more preferably satisfied, and the relational formula (c) is even more preferably satisfied. G and H may satisfy the relational formula (d). H≦-0.2G+25 (a) H≦-0.2G+24.5 (b) H≦-0.2G+24 (c) H≦-0.15G+18 (d)

[0104] The Japanese Industrial Standards numbers referenced for the measurements of gloss and haze are as described above.

[0105] <4-4. Method of forming optical layer> The method for forming the optical layer is not particularly limited, but may be, for example, as follows. First, the material constituting the matrix described above, for example, tetraethoxysilane, is dissolved under acidic conditions to generate a matrix precursor liquid. In addition, a dispersion containing the above-mentioned particles, for example, a smectite dispersion, is diluted with ethanol or the like to generate a microparticle dispersion. Then, the matrix precursor liquid and the microparticle dispersion are mixed to generate a coating liquid for the optical layer.

[0106] Next, a coating liquid is applied to the second surface of the cleaned glass plate 10. The application method is not particularly limited, but for example, a flow coating method, a spray coating method, a spin coating method, etc. can be adopted. Thereafter, the applied coating liquid is dried in an oven or the like at a predetermined temperature (for example, 80 to 120°C) for volatilizing the alcohol content in the solution, and then sintered at a predetermined temperature (for example, 400 to 650°C) for hydrolysis and decomposition of the organic chain, to obtain an optical layer.

[0107] <5.Features> The display device according to this embodiment can achieve the following effects. That is, since the anti-glare films 20, 30, 40, 50, 60 are laminated as optical layers on the cover members 100, 200, 300, 400, 500, the image on the display panel 500 can be clearly viewed. In addition, since the glass plate 10 and the display panel 500 are directly fixed by the adhesive layer 3 without an air layer therebetween, the image on the display panel 500 can also be clearly viewed.

[0108] Furthermore, in this display device, the glass plate 10 is chemically strengthened, and the second surface facing the outside (driver's side) has a greater compressive stress depth than the first surface. In particular, the glass plate 10 is manufactured by the float method, and the top surface with a high tin oxide concentration faces the outside as the second surface, so that when chemical strengthening is performed, the compressive stress layer depth of the second surface can be made greater than that of the first surface. Therefore, the strength of the surface of the cover member facing the inside of the vehicle is reduced, and it becomes more likely to break when it receives an impact. Therefore, for example, when the head of the driver or a passenger sitting in the passenger seat hits the display device due to an accident, the glass plate 10 becomes more likely to break due to the impact, and the impact received by the head can be reduced.

[0109] Furthermore, since the anti-glare films 20, 30, 40, 50, and 60 are organic-inorganic composite films, the organic components contained therein react with the tin oxide on the surface of the glass plate 10, and thus deterioration of the anti-glare films 20, 30, 40, 50, and 60 can be suppressed.

[0110] <6. Variations> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. The following modified examples can be appropriately combined.

[0111] <6-1> The configuration of the housing 4 is not particularly limited as long as it can accommodate the display panel 500 and the backlight unit 6. The display panel 500 may be anything other than the above-mentioned liquid crystal panel, such as an organic EL panel, a plasma display panel, or an electronic ink type panel. When a panel other than a liquid crystal panel is used as the display panel 500, the backlight unit 6 is not necessary. Air may be interposed between the display panel 500 and the cover member 100 instead of the adhesive layer 3.

[0112] <6-2> In the above embodiment, the cover member is in contact with the housing 4, but it may be in contact only with the display panel. <6-3> The glass plate 10 may be provided with a shielding layer 9 as shown in FIG. 9 so that a part of the display area of ​​the display panel 500 can be viewed. At least one opening 91 or cutout 92 is formed in the shielding layer 9 so that an image displayed on the display panel 500 can be viewed through the opening 91 or cutout 92. Such a shielding layer 9 may be formed on at least one of the first surface and the second surface of the glass plate 10. The optical layer may be laminated so as to cover the opening 91 or cutout 92, or may be formed on the shielding layer 9. The material for forming the shielding layer 9 is not particularly limited, and may be formed from, for example, ceramic or sheet material in a dark color such as black, brown, gray, or dark blue.

[0113] <6-4> In the above embodiment, the organic-inorganic composite film 20, 30, 40, 50, 60 having an anti-glare function as an optical layer is laminated on the second surface of the glass plate 10, but for example, fine irregularities can be formed on the second surface of the glass plate 10 by etching or the like, and the irregularities can provide an anti-glare function or an anti-reflection function. A layer having such irregularities also corresponds to the optical layer of the present invention. In the above embodiment, an anti-glare film is described as an example of the optical layer, but the optical layer may be another functional film, for example, a known anti-reflection film, anti-fogging film, heat reflection film, etc.

[0114] <6-5> In the above embodiment, a glass plate manufactured by the float method is used, but the manufacturing method of the glass plate is not particularly limited, and it is sufficient that the glass plate is at least chemically strengthened and the depth of the compressive stress layer of the second surface facing the outside is greater than that of the first surface.

[0115] <6-6> In the above embodiment, the display device of the present invention has been described as a display device for use in a vehicle, but is not limited thereto. The display device can be applied to all display devices used together with the above-mentioned display panel. In addition, the display device can be provided with a touch panel and used as a touch panel display. Therefore, the above-mentioned cover member can also be applied to various display devices. [Explanation of symbols]

[0116] 10 Glass Plate 20,30,40,50,60 Anti-glare film (optical layer) 500 Display Panel

Claims

1. A display panel; a cover member disposed on the display panel; Equipped with The cover member is A glass plate that has been chemically strengthened and has a first surface and a second surface having a compressive stress layer depth (dol) greater than that of the first surface; an optical layer laminated to a second surface of the glass plate and facing outward; Equipped with The optical layer contains at least a matrix and particles, the surface of the optical layer opposite to the second surface is unevenly formed by the particles, The optical layer includes a first region in which the particles are piled up in a thickness direction of the optical layer, and a valley-shaped second region that surrounds the first region or is surrounded by the first region, A display device, wherein the first region is a plateau-shaped region.

2. The display device according to claim 1 , wherein the glass plate is manufactured by a float process, and the first surface has a higher tin oxide concentration than the second surface.

3. The display device according to claim 1 , wherein the optical layer is an organic-inorganic composite film.

4. The display device according to claim 1 , wherein the second region includes a portion where the particles are not piled up or where no particles are present.

5. 5. The display device according to claim 1, wherein the first region has a width of 7.7 μm or more, and the second region has a width of 7 μm or more.

6. 5. The display device according to claim 1, wherein the first region has a width of 10 [mu]m or more, and the second region has a width of 10 [mu]m or more.

7. said grains being substantially composed of tabular grains; the tabular grains have a thickness in the range of 0.3 nm to 3 nm and an average diameter of the major faces in the range of 10 nm to 1000 nm; 4. The display device according to claim 1, wherein the major faces of the tabular grains are arranged approximately parallel to the second face of the glass plate.

8. A display panel; a cover member disposed on the display panel; Equipped with The cover member is A glass plate that has been chemically strengthened and has a first surface and a second surface having a compressive stress layer depth (dol) greater than that of the first surface; an optical layer laminated to a second surface of the glass plate and facing outward; Equipped with The optical layer contains at least a matrix and particles, the surface of the optical layer opposite to the second surface is unevenly formed by the particles, the optical layer has a region in which the particles are stacked in a thickness direction of the optical layer, and a region in which the particles are not stacked or no particles are present; A display device, wherein a difference between a highest point and a lowest point of the optical layer as measured from the second surface of the glass plate is three times or more the average particle size of the particles.

9. The display device according to claim 8, wherein Smr1 defined in ISO25178 is 10 to 30%.

10. 10. The display device according to claim 8, wherein a surface height BH20 at a load area ratio of 20% defined in ISO25178 is in the range of 0.04 μm to 0.5 μm.

11. 11. The display device according to claim 8, wherein a surface height BH80 at a load area ratio of 80% defined in ISO25178 is in the range of -0.3 μm to 0 μm.

12. The display device according to claim 1 , wherein Rsm of the surface of the optical layer is greater than 0 μm and is not greater than 35 μm. Here, the Rsm is the average length of the roughness curve element defined in JIS B0601:2001.

13. 13. The display device according to claim 1, wherein the Ra of the surface of the optical layer is in the range of 20 nm to 120 nm. Here, the Ra is the arithmetic mean roughness of the roughness curve defined in JIS B0601:2001.

14. The display device according to claim 1 , wherein the second surface of the glass plate has an Ra of 10 nm or less. Here, the Ra is the arithmetic mean roughness of the roughness curve defined in JIS B0601:2001.

15. 15. The display device according to claim 1, wherein the matrix is ​​mainly made of silicon oxide.

16. 16. The display device according to claim 1, wherein the glass plate has a thickness of 0.5 to 3 mm.

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