Image representation using light guide plate

Abstract

To provide an image display light guide plate which can suppress increase of haze even in a moist heat environment, can hold a clear image, and can exhibit an excellent productivity.SOLUTION: The present invention relates to an image display light guide plate in which a first resin base material, a first protection layer, and a hologram layer are arranged in that order in a thickness direction. The increase of haze of the first protection layer under an environment of 85°C and 85%RH after 500 hours have passed is not larger than 0.1%, and the surface water contact angle when the first protection layer is at the temperature of 23°C is not larger than 70 degrees.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a light guide plate for image display. [Background technology]

[0002] In some display devices, light guide plates for image display are used. For example, in VR (Virtual Reality) Virtual Reality (AR) technology or Augmented Reality (Augmented Reality) In a display device using the Reality technology, a hologram layer is supported on a transparent substrate. A light guide plate for image display is used.

[0003] As the transparent substrate, a glass substrate is often used. For this purpose, consideration has been given to changing the transparent substrate from glass to plastic. There are.

[0004] For example, Patent Document 1 discloses a hologram laminate used in an in-vehicle head-up display. The hologram laminate is made of an acrylic resin substrate, an acrylic adhesive, and a hologram-forming material. layer, a hologram layer made of an acrylic photopolymer, an acrylic adhesive layer, and an acrylic Furthermore, Patent Document 1 also describes a method for manufacturing an acrylic resin substrate. It is stated that the appearance of the hologram changes depending on the surface smoothness. If the maximum height Rmax, which indicates the surface smoothness of the laminate, exceeds 50 μm, the appearance of the hologram will deteriorate. On the other hand, if the maximum height Rmax is less than 25 μm, the appearance of the hologram changes significantly. The degree of degradation is within the acceptable range.

[0005] The transparent resin substrate such as the acrylic resin substrate may be made of a highly transparent resin. A resin-based hard coat layer is applied to the substrate to prevent scratches and improve chemical resistance, and a It is preferable to provide a gas barrier layer to prevent moisture absorption into the program layer. In order to improve the smoothness of such a hard coat layer, it is common to add a leveling agent. In addition, an anchor coat is used to improve adhesion between the hard coat layer and the gas barrier layer. An adhesive called an adhesive is often used. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-296583 Summary of the Invention [Problem to be solved by the invention]

[0007] However, such leveling agents tend to bleed onto the surface in high temperature and humidity environments. This change in the surface condition can cause an increase in haze, which can lead to This may cause a decrease in brightness when displaying an image. There is no mention of changes in the surface properties of the hologram laminate due to the application of the coating. In addition, adding a leveling agent to the hard coat layer improves the water repellency of the hard coat layer surface. In order to laminate another material layer, another coating is applied to the surface of this hard coat layer. When a coating agent was applied, cissing was more likely to occur. This may reduce the recoatability of the coating layer, impairing the productivity of the laminate. However, there is no mention of the recoatability of such a hard coat layer.

[0008] The present invention has been made in consideration of the above-mentioned problems, and is directed to an image display device using a resin substrate. The present invention aims to provide a light guide plate for an image display that is excellent in durability against humidity and heat and in productivity. The purpose is to [Means for solving the problem]

[0009] In view of this situation, the present inventors have developed a method for the irradiation of polyfunctional (meth)acrylates by UV irradiation. The resin material cured by radical polymerization reaction is used as the hard coat layer. Focusing on this, we have developed a Rebelin that contains a double bond and a perfluoroalkenyl group in the molecule. A leveling agent was applied to the hard coat layer. The adhesive chemically bonds with the multifunctional (meth)acrylate, allowing the adhesive to withstand high temperature and humidity conditions. In addition, the leveling agent was prevented from bleeding onto the surface of the hard coat layer. By making it difficult for fluorine to migrate, the water repellency of the hard coat layer is suppressed, improving recoatability. was done. The present invention has the following aspects. [1] A first resin substrate and a (meth)acrylate-derived repeating unit A first protective layer containing an acrylic resin and a hologram layer are arranged in this order in the thickness direction. a light guide plate for an image display, which is placed in an environment of 85° C. and 85% RH for the first protective layer; the increase in haze after 500 hours at 23°C is 0.1% or less, A light guide plate for image display, having a surface water contact angle of 70 degrees or less. [2] The first protective layer comprises a matrix resin component containing a polyfunctional (meth)acrylate; Compounds that have one or more double bonds and a perfluoroalkenyl group in the molecule [1] Light guide plate for image display. [3] The light guide plate for image display according to [1] or [2], wherein the compound is a leveling agent. [4] The content of the leveling agent in the (meth)acrylic resin composition is [3] The amount is 0.01 to 2 parts by mass per 100 parts by mass of the polyester resin component. Light guide plate for image display. [5] Any of [1] to [4], wherein the thickness of the first protective layer is 1 μm or more and 15 μm or less. A light guide plate for image display. [6] The image display device according to any one of [1] to [5], wherein the first protective layer further comprises a first inorganic material layer. light guide plate. [7] The first inorganic material layer is silicon oxide, silicon nitride, silicon nitride oxide, silicon sulfide, Aluminum oxide, aluminum nitride, aluminum nitride oxide and aluminum sulfide The image display conductive material according to any one of [1] to [6], which contains at least one inorganic material selected from the group consisting of: light board [8] The thickness of the first inorganic material layer is 50 nm or more and 5000 nm or less, [1] to [7 ] Light guide plate for image display. [9] The hologram layer is made of a single or volume hologram material, [1] to [8] Light guide plate for image display. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a light guide plate for image display that is excellent in durability against heat and humidity and in productivity. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing an example of a light guide plate for image display according to an embodiment of the present invention. [Figure 2] 10A and 10B are schematic front views for explaining a method for measuring a luminance value and an FOV. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following, embodiments of the present invention will be described with reference to the accompanying drawings. Even if the embodiments are different, the same or corresponding parts are denoted by the same reference numerals. Common explanations will be omitted. Numerical ranges expressed using "~" include the numerical values ​​on both sides of the "~". "UV" means ultraviolet light. "(Meth)acrylic" means one or both of acrylic and methacrylic. "(Meth)acrylate" means either or both of acrylate and methacrylate. do.

[0013] <Light guide plate for image display> A light guide plate for image display according to an embodiment of the present invention will be described. The plate has a first resin substrate, a first protective layer, and a hologram layer. The first protective layer is a layer having a thickness of 1000 nm and a thickness of 1000 nm. The first protective layer has a first organic material layer, and may also have a first inorganic material layer, if necessary. It is sufficient that the light-transmitting layer is disposed on at least one surface of the hologram layer. A second protective layer and a second resin substrate are disposed on the surface of the second protective layer in this order in the thickness direction, and a hologram layer is formed on the second resin substrate. A protective layer may be disposed on both surfaces. In this case, the hologram layer is formed by the first protective layer and the second protective layer. The first protective layer is sandwiched between the first and second protective layers, and the first resin base material is laminated on the other side of the first protective layer. A second resin base material is laminated on the other surface of the second protective layer. The first resin substrate and the second resin substrate may hereinafter be collectively referred to simply as "resin substrates." In addition, the first protective layer and the second protective layer may hereinafter be collectively referred to simply as "protective layer." In addition, the first organic material layer and the second organic material layer will be collectively referred to simply as "organic material layer" below. In addition, the first inorganic material layer and the second inorganic material layer will be collectively referred to as "inorganic material layer" hereinafter. It is sometimes called a "layer." FIG. 1 is a schematic cross-sectional view showing an example of a light guide plate for image display according to a modified example of an embodiment of the present invention. be.

[0014] Between the first resin substrate and the first organic layer, between the first organic material layer and the second inorganic material layer, and between the first inorganic One or more transparent layers may be disposed between the mechanical layer and the holographic layer. For example, an adhesive Examples of such layers include an adhesive layer, a hard coat layer, and an anchor coat layer.

[0015] The light guide plate for image display has an incident portion for receiving image light and a display portion for displaying an image based on the image light. The hologram layer is disposed between the incident portion and the display portion. The light guide element is configured to guide at least the image light incident from the incident portion to the display portion and emit the image light from the display portion. The diffraction grating pattern in the display section is formed to display an image. At least a part of the external light incident from the outside of the light guide plate for display is transmitted through the light guide plate. The light is incident from the opposite side.

[0016] The image light incident on the incident section is guided within the hologram layer and emitted to the outside from the display section. On the other hand, external light also passes through the resin substrate and the display unit, so that the viewer of the display unit can see both the image light and external light. Both can be observed within the field of view. The light guide plate for image display of this embodiment is suitable for display devices using VR technology and AR technology. For example, the light guide plate for image display of this embodiment can be used in automobiles as well as displays. Combiners for in-vehicle head-up displays (HUD) and reflective LCD display devices The optical element may be used in a device such as a holographic optical element (HOE), which is typified by a reflector for a light source.

[0017] Hereinafter, a detailed configuration of an example of the light guide plate for image display of this embodiment will be described based on the example shown in FIG. FIG. 1 is a schematic cross-sectional view showing an example of a light guide plate for image display according to an embodiment of the present invention. do.

[0018] In the light guide plate 6 for image display shown in FIG. 1, the first resin base material 1, the first organic material 2, and the a first inorganic material layer 22A, a first inorganic material layer 22B, a hologram layer 3, a second inorganic material layer 24B, a second organic The material layer 24A and the second resin base material 5 are disposed in this order. The planar shape of the light guide plate 6 for image display is not particularly limited. may be shaped so as to be attachable to the display device to be used. For example, the light guide plate 6 for image display is a rectangular plate larger than the shape to be attached to the display device. In this case, the light guide plate 6 for image display may be The material is cut or shaped into a shape that can be attached to the The light guide plate 6 for image display may be in the form of a flat plate, or may be in the form of a curved plate as required. stomach. In the following, an example will be described in which the image display light guide plate 6 is made of a flat plate that is rectangular in plan view.

[0019] [First resin base material 1] The first resin base material 1 is disposed at the outermost portion in the thickness direction of the light guide plate 6 for image display. The resin substrate 1 is disposed on the surface of the light guide plate 6 for image display on the display image output side. The first resin base material 1 has the same outer shape as the light guide plate 6 for image display. The first resin base material 1 is a base material for separating image light emitted from the hologram layer 3 and a second resin base material 5 (described later). and external light that passes through the hologram layer 3. The thickness of the first resin base material 1 is not particularly limited. For example, the thickness of the first resin base material 1 is 0.1 It may be between 1 mm and 10 mm. In this specification, the thickness of the first resin base material 1 is measured by a dial gauge method using a stylus or a machine. It can be measured using a micrometer, etc.

[0020] The material for forming the first resin base material 1 is not particularly limited, and may be any known transparent resin material. It is possible to use. Optical properties such as transparency and refractive index, as well as main physical properties such as impact resistance, heat resistance, and durability. In consideration of this, for example, a polymer such as a homopolymer or copolymer of ethylene, propylene, butene, etc. Olefin resins; amorphous polyolefin resins such as cyclic polyolefin resins; polyethylene Polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) Cellulose-based resins such as triacetyl cellulose, diacetyl cellulose, and cellophane Resins: Polyamide resins such as nylon 6, nylon 66, nylon 12, copolymer nylon, etc. Ethylene-vinyl acetate copolymer partial hydrolyzate (EVOH), polyimide resin, poly Etherimide resin, polysulfone resin, polyethersulfone resin, polyether Polyether ketone resin, polycarbonate resin, polyvinyl butyral resin, poly Arylate resins, fluororesins, poly(meth)acrylic resins, polystyrene and other styrenes resins, polyvinyl alcohol, ethylene vinyl alcohol copolymers, polyvinyl chloride, Cellulose, acetyl cellulose, polyvinylidene chloride, polyphenylene sulfide, poly Polyurethane, phenolic resin, epoxy resin, polynorbornene, styrene-isobutylene Styrene-styrene block copolymer (SIBS), allyl diglycol carbonate, biodegradable The first resin base material 1 may be made of two or more materials. Alternatively, it may have a laminated structure in which two or more materials are laminated. In terms of transparency, polycarbonate resins, poly(meth)acrylic resins, etc. are used. From the viewpoint of process resistance, it is more preferable to use poly(meth)acrylic resins, ethylenediaminetetraacetic acid, and the like. It is more preferable to use epoxy resin, cyclic polyolefin resin, etc.

[0021] [First organic material layer 22A] The first organic material layer 22A contains a repeating unit derived from a polyfunctional (meth)acrylate (methacrylate). The first organic material layer 22A is disposed on the surface of the first resin base material 1. This prevents the first resin base material 1 from being deteriorated by the hologram layer 3. 1. It increases the range of materials that can be used.

[0022] The (meth)acrylic resin of the first organic material layer 22A is a polyfunctional (meth)acrylic resin. Any repeating unit derived from a monofunctional (meth)acrylate may be used. It may contain repeating units of the formula: Multifunctional (meth)acrylates have two or more radically polymerizable functional groups in the molecule. (Meth)acrylate means (meth)acrylate. Examples of polyfunctional (meth)acrylates that can be used as raw materials for (meth)acrylic resins include: Polyethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate Acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol Tri(meth)acrylate, tricyclodidecanedimethanol di(meth)acrylate, etc. Examples of suitable polyfunctional (meth)acrylates include the following: Furthermore, examples of monofunctional (meth)acrylates include isobornyl (meth)acrylate. acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxy-3-phenoxy Propyl (meth)acrylate, butoxyethyl (meth)acrylate, lauryl (meth)acrylate ) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, Xyldiglycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate , 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, Phenoxyethyl (meth)acrylate, dicyclopentadiene (meth)acrylate, poly Polyethylene glycol (meth)acrylate, Polypropylene glycol (meth)acrylate acrylate, nonylphenoxyethyl cellosolve (meth)acrylate, etc. These (meth)acrylates may be used alone or in combination of two or more. A polymer may be formed.

[0023] In addition to the (meth)acrylic resin, a polyfunctional (meth)acrylate is also used. For example, oligourethane (meth)acrylate, Polyester (meth)acrylate and the like.

[0024] The (meth)acrylic resin has a repeating unit derived from a polyfunctional (meth)acrylate. By doing so, it is possible to have a crosslinked structure, which makes it difficult for the hologram material to swell and is resistant to the A light guide plate having excellent chemical resistance and long-term visibility can be obtained. The method for forming the first organic material layer 22A is not particularly limited. A (meth)acrylic resin composition containing a methacrylate as a matrix resin component is added to a first resin substrate. The (meth)acrylic resin composition can be applied to the surface of the substrate and then cured to form the film. do. Examples of methods for applying the (meth)acrylic resin composition include air doctor coating. Coating, blade coating, knife coating, reverse coating, transfer Roll coating, gravure roll coating, kiss coating, cast coating coating, spray coating, slot orifice coating, calendar coating Coating methods such as electroplating, dip coating, and die coating Flexographic printing and other relief printing methods, direct gravure printing, offset gravure printing intaglio printing methods such as offset printing, lithographic printing methods such as screen printing, etc. Examples of printing methods include:

[0025] The (meth)acrylic resin composition may be optionally coated with a polyisoprene or acrylic acid to adjust viscosity or improve coating properties. The dilution solvent may be various organic solvents. Examples of suitable solvents include methanol, ethanol, 1-propanol, 2-propanol, and the like. Alcohol compounds such as alcohol; ketone compounds such as acetone and methyl ethyl ketone; Ester compounds such as ethyl acetate, propyl acetate, and butyl acetate; toluene, xylene, etc. These dilution solvents can be used alone or in combination of two or more. It is possible.

[0026] The (meth)acrylic resin composition may contain a photopolymerization initiator as needed. Examples of the photopolymerization initiator include benzophenone, acetophenone, benzoin, and benzophenone. Benzoin isobutyl ether, benzoin isopropyl ether, benzoin ethyl ether , 4,4'-bis(dimethylamino)benzophenone, benzil dimethyl ketal, 2- Chlorothioxanthone, 2,4-dimethylthioxanthone, 2,2'-diisopropyl Thioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4 -(methylthio)phenyl)-2-morpholinopropan-1-one, 2,4,6-tri methylbenzoylphenyldiphosphine oxide, etc. These may be used alone or in combination. More than one type can be used in combination.

[0027] The (meth)acrylic resin composition has excellent properties, which are advantageous for the light guide plate for image display of the present invention. In order to provide the above-mentioned properties, various additives may be added in addition to the matrix resin component. This can be done. Additives include viscosity modifiers, coating property improvers, leveling agents, UV absorbers, and antioxidants. The above-mentioned additives, such as anti-scratch agents, anti-friction agents, etc., can be appropriately blended. 1. By imparting high smoothness to the protective layer, the optical properties of the light guide plate for image display of the present invention can be improved. It is preferable to use a leveling agent because this tends to improve the surface roughness and durability.

[0028] On the other hand, as the additives, when the (meth)acrylic resin composition is cured, It has one or more double bonds in the molecule that can chemically bond with the PEG resin component. Compounds such as these are preferred. A cured product of a (meth)acrylic resin composition containing such a compound as an additive is used as a first compound. By using a synthetic material layer, the additives can be absorbed from the first protective layer even in a high temperature and high humidity environment. The light guide plate for image display of the present invention can suppress the occurrence of a drop-out. The haze increase under the conditions of 85% RH and 500 hours can be kept to 0.1% or less. can. As these additives, compounds having a perfluoroalkenyl group are preferred. A cured product of a (meth)acrylic resin composition containing such a compound as an additive is treated as a first organic solvent. By using this material layer, fluorine is less likely to migrate to the surface of the first protective layer, suppressing water repellency. That is, the surface water contact angle of the first protective layer at 23°C is set to 70 degrees or less. This improves the recoatability of the first protective layer. In this application, the perfluoroalkenyl group refers to a fluorine-containing group having two or more carbon atoms. It is preferable that the number of the perfluoroalkenyl groups is 4 to 20, and more preferable that the number of the perfluoroalkenyl groups is 4 to 20. , -CF(CF3)C(=C(CF3)2)(CF(CF3)2) structure is preferred. More preferable. Therefore, the leveling agent may be, for example, an acrylic leveling agent or a silicone leveling agent. Suitable examples of the leveling agent include a leveling agent and a fluorine-based leveling agent. acrylate-based polymers and oligomers containing ter, alkyl, polyester, etc. in the side chain; Silicone-based polymers and oligomers having silicone chains and polyalkylene oxide chains mers, silicone-based polymers and oligomers having silicone chains and polyester chains; Fluorine-based polymer having a perfluoroalkyl group and a polyalkylene oxide chain, and Oligomers, and perfluoroalkyl ether chains and polyalkylene oxide chains However, for the reasons mentioned above, Representative examples include the P series (manufactured by Shin-Etsu Silicone Co., Ltd.) and the Polyflow KL series (manufactured by Kyoeisha Chemical Co., Ltd.). Silicone polymers and oligomers having ethylenically unsaturated groups, or megaf FAC RS series (DIC), KY400 series (Shin-Etsu Silicone), Futerji Fluorine-based polymers and oligomers, such as the Entol series (manufactured by Neos Co., Ltd.) and a polymer having one or more double bonds in the molecule that can chemically bond with the matrix resin component. It is preferable to use the compounds having the above properties, and among them, the Futergent series (manufactured by Neos Co., Ltd.) It is more preferable to use a compound having a hexafluoropropylene trimer group in the molecule, such as Preferred.

[0029] Furthermore, these leveling agents are used in an amount of 0. It is preferable to use it in the range of 0.1 part by mass or more and 2 parts by mass or less. By setting the blending amount of the leveling agent to 0.01 parts by mass or more, it is possible to polish the first protective layer. The smoothness and scratch resistance can be improved without polishing, and it can be used as a polished light guide plate for image display. There is a tendency that useful processing precision can be easily obtained. More preferably, it is 0.1 parts by mass or more. In addition, by making the blending amount of the leveling agent 1 part by mass or less, it is possible to obtain a light guide plate for image display. This provides sufficient transparency and mechanical strength, and also suppresses the increase in haze in high-temperature, high-humidity environments. It is more preferably 1 part by mass or less.

[0030] In addition, a silane coupling agent is added to the acrylic resin composition, and the first organic It is also possible to adjust the adhesion between the material layer 22A and the first resin base material. In order to strengthen the adhesion between the insulating material layer 22A and the first resin substrate, a silane coupling agent is used. It is possible. A typical example of the silane coupling agent is an aminosilane compound. Specific examples of the silane compound include γ-aminopropyltriethoxysilane, γ-amino Propyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane oxysilane, γ-ureidopropyltriethoxysilane, γ-N-phenylaminopropyl These aminosilanes can be used alone or in combination of two or more. Furthermore, coupling agents other than aminosilanes may be used in combination. do not have.

[0031] The thickness of the first protective layer 2 including the first organic material layer 22A is preferably 1 μm or more. Preferably, it is 2 μm or more, more preferably 5 μm or more. When the thickness of the first protective layer 2 is 1 μm or more, the hologram layer 3 can effectively prevent the resin substrate from being damaged. The thickness of the first protective layer 2 is preferably 15 μm or less. It is more preferable that the thickness is 2 μm or less, and even more preferable that the thickness is 10 μm or less. By making the thickness of the first protective layer 2 15 μm or less, the elastic modulus of the first protective layer 2 can be increased. can. The thickness of the first protective layer 2 can be measured using a non-contact optical interference film thickness meter or the like.

[0032] The elastic modulus of the first organic material layer 22A is preferably 2 GPa or more, and more preferably 5 GPa or more. It is more preferable that the modulus of elasticity is 2 GPa or more. The elastic modulus of the first organic material layer 22A is 20 GPa or less. The elastic modulus is preferably 20 GPa or less, and more preferably 15 GPa or less. By satisfying the condition below, warpage due to cure shrinkage during the formation of the organic layer can be suppressed. The elastic modulus was measured using a Shimadzu dynamic ultra-micro hardness tester, DUH-W201. Conditions: Triangular 115, measurement possible with an indentation depth of 230 to 280 nm .

[0033] The difference in refractive index between the first resin base material 1 and the first organic material layer 22A is 0.3 or less. It is preferable that the difference in refractive index is 0.3 or less, and more preferable that the difference is 0.2 or less. This allows for excellent brightness to be imparted and prevents color unevenness. The refractive index is measured using a commonly used Abbe refractometer or ellipsometer. It can be measured.

[0034] [First inorganic material layer] The first inorganic material layer 22B may be appropriately used for the purpose of preventing moisture absorption into the hologram layer. In this case, in the light guide plate for image display according to the embodiment of the present invention, 1. The resin substrate, the first organic material layer, the first inorganic material layer, and the hologram layer are arranged in the thickness direction, In this case, the moisture absorption prevention performance of the hologram layer is improved. Since the deterioration of the resin substrate due to the hologram layer tends to be prevented, the first inorganic material layer It is preferable that the hologram layer is in direct contact with the substrate. The inorganic material used in the first inorganic material layer 22B may be silicon oxide, silicon nitride, or nitride. Silicon oxide, silicon sulfide, aluminum oxide, aluminum nitride, aluminum nitride oxide Alternatively, aluminum sulfide may be mentioned. Among these, silicon oxide and silicon nitride oxide are preferred from the viewpoint of improving total light transmittance and barrier properties. Aluminum oxide, aluminum nitride, and aluminum oxide are preferred. Sodium and potassium are particularly preferred. The lower the alkaline oxide content, the less the barrier properties can be reduced under high temperature and humidity conditions. is preferable.

[0035] The thickness of the first inorganic material layer 22B is preferably 50 nm or more and 5000 nm or less. The layer thickness is preferably 50 nm or more and 3000 nm or less. The effect of preventing moisture absorption into the hologram layer is obtained, and sufficient resistance to the hologram material is also obtained. Furthermore, since the layer thickness is 5000 nm or less, cracks are less likely to occur in the protective layer 22. The thickness of the layer is particularly preferably 50 nm or more and 1000 nm or less.

[0036] The inorganic material used for the first inorganic material layer 22B is a material having a higher molecular weight than the first resin base material 1 and the first organic material layer 22A. For example, the refractive index of the first inorganic material layer 22B may be 1.4 or higher. The refractive index of the first inorganic material layer 22B may be 8 or more and 3.0 or less. The light passing through the first resin base material 1 via the layer 22 is absorbed from the optically dense first inorganic material layer 22B. The light then passes through the optically rough first organic material layer 22A and enters the first resin base material 1. The angle of emergence of light from the first protective layer 22 toward the first resin base material 1 is 1. As a result, the FOV ( This can widen your field of view.

[0037] The method for forming the first inorganic material layer 22B is not particularly limited. For example, a vacuum deposition method, a spa Conventionally known methods such as tarring, ion plating, and plasma CVD are used. The first inorganic material layer 22B can be formed by any of the following methods. When doing so, the coating surface is subjected to corona discharge treatment in order to improve the adhesion between the coating surface and silicon oxide. , low temperature plasma treatment, and the use of silane coupling agents, saturated polyester and isopropyl alcohol. Surface treatment such as coating with a cyanate mixture may also be performed. For example, when forming a thin film of silicon oxide by vacuum deposition, silicon is used as the evaporated material. silicon monoxide, silicon dioxide, or a mixture of these, -3 Torr~ 1.0×10 -5 Heating under a Torr vacuum using electron beam, resistance heating, or high frequency heating Alternatively, reactive evaporation can be used, which is carried out while supplying oxygen gas. When a layer made of silicon nitride oxide is formed as the first inorganic material layer 22B, the silicon nitride oxide The first inorganic material layer 22B is mainly composed of silicon oxide, except that silicon nitride oxide is used instead. A similar configuration is used.

[0038] When forming a layer made of aluminum oxide as the first inorganic material layer 22B, for example, It may be formed only from Al2O3, or it may be formed by mixing Al, AlO, Al2O3, etc. The atomic ratio of Al:O in the aluminum oxide layer may be The aluminum oxide usable for the first inorganic material layer 22B varies depending on the conditions for producing the inorganic material layer. The compound layer contains trace amounts (up to 3% of the total components) of other components within a range that does not impair the dense performance. may be included. The thickness of the aluminum oxide layer may be set as needed, such as for chemical resistance. For example, the thickness of the aluminum oxide layer may be 5 nm or more and 800 nm or less.

[0039] There is no particular limitation on the method for forming the first inorganic material layer 22B using aluminum oxide. For example, the first inorganic material layer 22B can be formed by a method such as vacuum deposition, sputtering, or ion plating. PVD (physical vapor deposition) methods such as the CVD (chemical vapor deposition) method are used. Good too. For example, in the vacuum deposition method, Al, Al2O3, etc. are used as the deposition source material. Heating methods for deposition sources include resistance heating, high-frequency induction heating, and electron beam heating. In the vacuum deposition method, reactive gases such as oxygen, nitrogen, and water vapor are introduced. Reactive deposition using ozone addition, ion assist, or other means may also be used. Applying a bias to the substrate on the film-forming surface, or increasing or decreasing the temperature of the film-forming surface The same applies to other film formation methods such as sputtering and CVD.

[0040] [Hologram layer 3] The hologram layer 3 is laminated on the surface of the first protective layer 2. The hologram layer 3 has a particular structure. The hologram layer 3 may be formed of an appropriate material corresponding to the functions required for the image display light guide plate 6. A diffraction grating of the above is formed. The material of the hologram layer 3 is not particularly limited, and may be a known resin material for forming a hologram. stomach. For example, a polymer having at least one solvent-soluble, cationic polymerizable ethylene oxide ring in its structural unit is and a hologram comprising a thermosetting resin having one of the above and a radically polymerizable ethylenic monomer. Ram recording materials (JP-A Nos. 9-62169, 11-161141, 2002) 002-310932). Specifically, epoxy resins such as bisphenol-based epoxy resins; triethylene glycol (Meth)acrylates such as butyl diacrylate; 4,4'-bis(tert-butylphenyl) (i) Photopolymerization initiators such as iodonium hexafluorophosphate; 3,3'-carbonyl A wavelength sensitizer such as rubis(7-diethylamino)coumarin; an organic solvent such as 2-butanone, It is preferable that the light-sensitive material contains the above-mentioned photosensitive material. In particular, it is preferable that the hologram layer is made of a single or volume hologram material. .

[0041] [Second inorganic material layer 24B] The second inorganic material layer 24B is a part of the second protective layer 24 and is connected to the first hologram layer 3 via the hologram layer 3. The second inorganic material layer 24B is laminated on the opposite side of the protective layer 2. The same configuration as that exemplified in the description of the second inorganic material layer 2B is used. The thickness, material, etc. of 4B may be different from those of the first inorganic layer 22B.

[0042] [Second organic material layer 24A] The second organic material layer 24A is a part of the second protective layer 24, and the description of the first organic material layer 22A is omitted. The same configuration as that exemplified in is used, except that the thickness of the second organic material 24A, The material may be different from that of the first organic material layer 22A.

[0043] [Second resin base material 5] The second resin base material 5 is laminated on the surface of the second protective layer 24. The second resin base material 5 is The same configuration as that exemplified in the description of the first resin base material 1 is used. The thickness, material, etc. of the resin base material 5 may be different from those of the first resin base material 1. In particular, The material 5 is a surface of the light guide plate 6 for image display on the side opposite to the display image output side on the side on which external light is incident. Since the first resin base material 1 is disposed on the first resin base material 2, a material having a higher surface hardness than the first resin base material 1 may be used.

[0044] [Light guide plate for image display 6] The light guide plate 6 for image display is formed between the first resin substrate 1 and the hologram layer 3 and between the second resin substrate 5 A first protective layer 22 and a second protective layer 24 are disposed between the first protective layer 22 and the hologram layer 3, respectively. The first protective layer 22 includes a first organic material layer 22A and a first inorganic material layer 22B. The protective layer 24 includes a second organic material layer 24A and a second inorganic material layer 24B. The first protective layer 22 has a first organic material layer 22A disposed on the side of the first resin base material 1 and a first inorganic material layer 22B disposed on the side of the first resin base material 1. It is preferable that the material layer 22B is disposed on the side of the hologram layer 3. In addition, the second protective layer 24 In this case, the second organic material layer 24A is disposed on the side of the second resin base material 2, and the second inorganic material layer 24B is disposed on the side of the second resin base material 2. It is preferable that the insulating layer 1 is disposed on the program layer 3 side. The chemical resistance of the first resin base material 1 and the second resin base material 5 varies depending on the type of resin material. However, it is significantly lower than that of glass. Therefore, the first resin base material 1 and the second resin base material 5 , has lower solvent resistance than glass, and is less resistant to hologram materials. When the first resin substrate 1 and the second resin substrate 5 are in contact with the hologram layer 3, the hologram The hologram material, which is a component of the layer 3, passes through the first resin substrate 1 and the second resin substrate 5, The hologram material tends to accumulate inside the first resin base material 1 and the second resin base material 5. When the first resin substrate 1 and the second resin substrate 5 are exposed to the hologram agent, The substrate 5 deteriorates, and the clarity is likely to decrease. Therefore, the first resin substrate 1 and the second resin substrate 5 are provided between the hologram layer 3 and the first resin substrate 1, respectively. By providing the protective layer 2 and the second protective layer 4, the first resin base material 1 and the second resin base material 5 By suppressing the penetration of the hologram agent, deterioration of the resin substrate is prevented.

[0045] <Method of manufacturing a light guide plate for image display> The light guide plate 6 for image display can be manufactured, for example, as follows. The first resin base material 1 and the second resin base material 5 are prepared ([substrate preparation step]). and a first organic material layer 22A and a second organic material layer 24A are formed on the surfaces of the second resin base material 5, respectively. The first step of forming an intermediate body consisting of a resin substrate and an organic material layer is The first inorganic material layer 22B and the second inorganic material layer 24A are formed on the surfaces of the first organic material layer 22A and the second organic material layer 24A. An inorganic material layer 24B is formed on each of the layers (inorganic material layer forming step). A photosensitive material for forming a hologram is applied to the surface of the first inorganic material layer 22B. A transparent seal layer having the same thickness as the hologram layer 3 is provided on the outer periphery of the first inorganic material layer 22B. In this case, the photosensitive material is applied to the recessed portion surrounded by the sealing layer. The sealing layer seals the outer periphery of the hologram layer 3 after the hologram layer 3 is formed. Thereafter, the second resin substrate 5 on which the second protective layer 24 is formed is 4 is placed facing the photosensitive material ([Light guide plate manufacturing process]). Thereafter, the first resin substrate 1, the first protective layer 2, the hologram layer 3, and the second A laminate including the protective layer 4 and the second resin base material 5 is bonded together. After this, interference fringes corresponding to the diffraction pattern are formed in the photosensitive material of the laminate, and A diffraction grating is formed. In this manner, the light guide plate 6 for image display is manufactured.

[0046] When the inorganic material is silicon oxide, the inorganic material layer can be formed as follows. After the intermediate body consisting of the resin substrate and the organic material layer is placed in a vacuum deposition device, a silicon oxide film is deposited. The vacuum level in the chamber of the vacuum deposition device is 3 x 10 -3 Torr and below It is preferable to use a high-frequency induction heating method under this vacuum to produce silicon monoxide with a purity of 99.9%. The silicon oxide is heated and evaporated to form a thin film of silicon oxide on the surface of the resin substrate. An intermediate laminate having a thin film oxide layer formed thereon is obtained. Thereafter, the light guide plate 6 for image display is formed.

[0047] When the inorganic material is alumina, the inorganic material layer can be formed as follows. An intermediate consisting of a resin substrate and an organic material layer is placed in an electron beam evaporation device, and Alpha alumina particles with a purity of 99.999% and a particle size of 0.5 to 5 mm are placed in an appropriate amount. The distance from the evaporation source to the shutter is approximately 3 to 15 cm, and the evaporation source is located on the surface of the resin substrate. The distance to the surface is preferably about 5 to 50 cm. The pressure in the electron beam evaporation equipment is 3×10 -3 After reaching Torr or less, the electron beam filler The ment current is increased to 25-50mA, the shutter is opened, and alumina film is formed. When the surface temperature reaches 45°C or higher, the shutter closes and the electron beam filament current is stopped. After cooling to 35°C or less, the filament current of the electron beam is increased to 25-50mA and the vapor is evaporated. The deposition source is heated, the shutter is opened, and the alumina film is deposited. This process is repeated until the alumina film is deposited. As a result, an intermediate laminate body on which an alumina thin film layer is formed is obtained. Thereafter, the light guide plate 6 for image display is formed.

[0048] <brightness value> Here, an example of a method for measuring the luminance value of the light guide plate 6 for image display will be briefly explained. . FIG. 2 is a schematic front view illustrating a method for measuring the luminance value.

[0049] As shown in FIG. 2, in order to measure the luminance value of the light guide plate 6 for image display, The display device 10 is manufactured using the above. The display device 10 includes an image light projection unit 13 and an incident optical system 12 in addition to the light guide plate 6 for image display. Equipped with. The image light projection unit 13 projects an image in response to an image signal sent from a controller (not shown). Image light to be displayed is projected onto the display light guide plate 6 . The incident optical system 12 includes, for example, a prism. The image light emitted from the light guide plate 6 for image display is incident on the incident portion 6a provided on the surface of the light guide plate 6 for image display. For example, the incident portion 6a is provided on the surface on the resin base material 1 side. The image light incident on the incident portion 6a passes through the waveguide diffraction grating portion 3b formed in the hologram layer 3. The light then reaches the diffraction grating portion 3c for display in the hologram layer 3. The image light is diffracted at positions corresponding to the respective display pixels. In the example shown in FIG. 2, the display unit 6d is made of a resin base material. It is formed on the surface on side 1 at a position spaced apart from the incident part 6a.

[0050] The luminance value of the light guide plate for image display 6 is measured by placing the display device 10 in a measuring device 15. This is done accordingly. The measuring device 15 includes a holding table (not shown), a luminance meter 14, a gonio stage (not shown), Equipped with. The support base holds the display device 10. The luminance meter 14 measures the luminance value of the received light. The stage supports the luminance meter 14 so that it can swing around the circumference of the stage, the center of rotation being the center. The distance d between the luminance meter 14 and the display surface 3a is determined based on the position of the user's eyes when the display device 10 is worn. For example, if the display device 10 is a head-mounted display, d is set to 15 mm.

[0051] The luminance value of the light guide plate 6 for image display was measured by setting the luminance meter 14 at a position of 0° of oscillation angle (solid line in FIG. 2). The display device 10 is placed on a support stand (see the luminance meter 14) and measured. The center of a is located on the measurement optical axis of the luminance meter 14 and faces the luminance meter 14 . The luminance value is measured by the luminance meter 14 when a white image with maximum luminance is displayed on the display device 10. This is the brightness that can be obtained. The brightness value is preferably 1000 nit or more, and more preferably 1200 nit or more. [Example]

[0052] The present invention will be explained in more detail below with reference to Examples and Production Examples. The examples and preparations are not intended to be limiting.

[0053] [Example 1] The resin substrate material is PMMA (Mitsubishi Chemical Corporation's "Acrylite (registered trademark)" The resin substrate is a rectangular plate measuring 60 mm wide x 60 mm long x 1 mm thick.

[0054] [Substrate preparation process] In the substrate preparation step, the resin base material is washed and dried. The resin substrate was treated with a neutral detergent, Semiclean (registered trademark) M-LO (product name: Yokohama Oil & Fat). The sample is then immersed in a 5% aqueous solution of surfactant (manufactured by Kogyo Co., Ltd.) and ultrasonically cleaned for 5 minutes. After this, the resin substrate is immersed in ultrapure water and ultrasonically cleaned for 5 minutes. The resin substrate was rinsed with water, air-dried, and then placed in an oven at 80°C under a nitrogen atmosphere. After this, the air-dried evaluation sample B is dried in a UV ozone cleaner for 1 minute. Ozone cleaning. This completes the substrate preparation process.

[0055] [Organic material layer formation process] In the organic material layer forming step, an organic material layer is formed on the surface of the resin substrate. Shiko 7600B (Mitsubishi Chemical Corporation, isophorone diisocyanate / pentaerythritol) Omnirad 184 as initiator for 100 parts by mass of thritol triacrylate (manufactured by IGM Resins) 4 parts by mass, and Futergent 602A as a leveling agent (fluorine-based leveling agent, manufactured by Neos Corporation) was added, and MEK (methyl ethyl ketone) was added. propylene glycol monomethyl ether acetate (Sankyo Chemical Co., Ltd.) and PGM (propylene glycol monomethyl ether acetate (Sankyo Chemical Co., Ltd.) The solid content was adjusted to 40% by mass in a mixed solvent of 7:3 (manufactured by Chemical Co., Ltd.). The mixture for the substrate layer was obtained. The mixture was applied to the base resin using a bar coater, and then coated with a high-pressure water. Silver lamp (integrated light output: 500 mJ / cm 2 ) to a thickness of 5 μm after curing. The organic material layer is formed as follows. This completes the organic material layer forming process.

[0056] [Inorganic material layer formation process] In the inorganic material layer forming step, an inorganic material layer is formed on the surface of the organic material layer. After the resin substrate on which the organic material layer has been formed is placed in a vacuum deposition device, vacuum deposition of silicon oxide is performed. The ultimate vacuum level in the chamber of the vacuum deposition device is 1.0 x 10 -4 Let's call it Torr. Under this vacuum, silicon monoxide with a purity of 99.9% is heated and evaporated using a high-frequency induction heating method. A silicon oxide thin film having a thickness of 100 nm is formed on the surface of the organic material layer. This completes the inorganic material layer forming step, and intermediate 1 is obtained. By this operation, an organic material layer and an inorganic material layer are formed in this order on the base resin, and this is called an "intermediate It's called the "body."

[0057] [Example 2] In Example 2, the addition of Futergent 602A, a leveling agent contained in the organic material layer, Intermediate 2 was obtained in the same manner as in Example 1, except that the amount was 0.3 parts by weight.

[0058] [Example 3] In Example 3, the addition of Futergent 602A, a leveling agent contained in the organic material layer, Intermediate 3 was obtained in the same manner as in Example 1, except that the amount was 0.5 parts by weight.

[0059] [Comparative Example 1] Comparative Example 1 was the same as Example 1 except that the leveling agent contained in the organic material layer was not added. Intermediate 4 was obtained by the same procedure as in 1.

[0060] Comparative Example 2 In Comparative Example 2, the leveling agent contained in the organic material layer was Polyflow PF75 (acrylic, Intermediate 5 was obtained in the same manner as in Example 1, except that 0.5 parts by weight of methylparaben (manufactured by Kyoeisha Chemical Co., Ltd.) was used. Ta.

[0061] Comparative Example 3 In Comparative Example 3, the leveling agent contained in the organic material layer was BYK361N (acrylic, BY Intermediate 6 was obtained in the same manner as in Example 1, except that 0.5 parts by weight of the hydroxybenzoate (manufactured by Company K) was used.

[0062] Comparative Example 4 In Comparative Example 4, the leveling agent contained in the organic material layer was Polyflow KL402 (a silicone-based Intermediate 7 was prepared in the same manner as in Example 1, except that 0.5 parts by weight of ethanol (manufactured by Kyoeisha Chemical Co., Ltd.) was used. Got it.

[0063] Comparative Example 5 In Comparative Example 5, the leveling agent contained in the organic material layer was Megafac RS75 (fluorine-based, Intermediate 8 was obtained in the same manner as in Example 1, except that 0.5 parts by weight of the hydroxybenzoate (manufactured by DIC Corporation) was used.

[0064] <Humidity and heat durability test> The humidity and heat durability test was carried out using a small environmental tester SH-241 (product name: manufactured by Espec Corporation). The intermediate was then maintained under conditions of 85°C and 85% RH for 500 hours.

[0065] <Haze measurement> Haze measurement was performed using a haze meter NDH7000II manufactured by Nippon Denshoku Industries Co., Ltd. The haze difference (Δ haze) before and after the moist heat test was calculated.

[0066] <Presence or absence of double bonds> The presence or absence of double bonds in the leveling agent can be determined from the molecular structure provided by the manufacturer. It was determined that: <Presence or absence of perfluoroalkenyl group> The presence of perfluoroalkenyl groups in the leveling agent was confirmed by Fourier transform infrared analysis (FT-IR). R) and gas chromatography-mass spectrometry (GC-MS) can be used to determine whether or not it is present. .

[0067] <Recoatability> Recoatability was evaluated by applying an anchor coating material to the surface after forming the organic material layer and observing how the liquid repels the material. It can be determined by observation. The anchor coat material was a polyester resin (trade name "Byron 63SS" by Toyo Manufactured by Boshinsha, hydroxyl value: 5 mg KOH / g) and an isocyanate compound (trade name "Coronate H X", manufactured by Tosoh Corporation, isocyanurate structure trimer of hexamethylene diisocyanate) NCO (number of isocyanate groups in isocyanate compound 1) / OH (number of isocyanate groups in polyester resin) An anchor coating liquid is used that is formulated so that the number of hydroxyl groups in fat (1) = 1 (molar ratio). After forming the organic material layer, the above anchor coat liquid is applied to the surface with a bar coater. If the coating was successful without any cissing, it was marked as "〇", if cissing was observed in some areas, it was marked as "△", and if cissing was observed on the entire surface, it was marked as "〇". If this is seen, mark it as "X".

[0068] <Water contact angle> The water contact angle was measured by measuring the surface after forming the organic material layer at 23°C using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). Measurements were performed using a Drop Master 500.

[0069] Table 1 shows the configurations and measurement results of each example and comparative example.

[0070] [Table 1]

[0071] <Evaluation results> As shown in Table 1, the haze change before and after the moist heat test in Examples 1 to 3 (in Table 1, "haze increase" is shown) ") is 0.1 or less, and it can be determined that the film has excellent humidity and heat stability. Furthermore, the water contact angle of the surface of the organic material layer was low, and recoatability was also good. In contrast, the haze change before and after the wet heat test in Comparative Examples 1 to 3 exceeded 0.1. It can be determined that none of them are excellent in humidity and heat stability. In addition, in Comparative Examples 2 to 5, the water contact angle of the organic material layer surface was high, and in particular, in Comparative Examples 3 to 5 In this case, the recoatability was poor.

[0072] Next, examples of light guide plates for image displays using the above-mentioned intermediate products will be described. The plate can be manufactured by carrying out the light guide plate manufacturing process described below.

[0073] [Example 4] In Example 4, the intermediate 1 is used to produce a light guide plate 6 for image display according to the embodiment. The photosensitive material for the hologram layer 3 is a bisphenol-based epoxy resin jER( Registered trademark) 1007 (polymerization degree n = 10.8, epoxy equivalent: 1750-2200, Mitsubishi 100 parts by weight of ethylene glycol diacrylate (manufactured by Mikal), 50 parts by weight of triethylene glycol diacrylate and 4,4 '-Bis(tert-butylphenyl)iodonium hexafluorophosphate 5 0.5 parts by mass of 3,3'-carbonylbis(7-diethylamino)coumarin and 2-bromo The material dissolved in 100 parts by weight of Tanon (hereinafter referred to as "photosensitive material A") is used. .

[0074] [Light guide plate manufacturing process] In the light guide plate manufacturing process of Example 4, two intermediate bodies 1 were used to manufacture a light guide plate 6 for image display. do. A sealing layer having a width of 5 mm and a thickness of 5 μm is applied to the peripheral edge of the protective layer of one of the intermediate bodies. The sealing layer is made of a transparent material and can be any material that can bond the protective layers of the intermediate body together. In Example 4, the optical adhesive Hardlock (registered trademark) OP-104 was used, but is not limited thereto. 5K (trade name; manufactured by Denka Co., Ltd.) is used. As a result, the opening surrounded by the sealing layer is a seal having a size of 50 mm x 50 mm. A layer-stepped intermediate substrate is provided. After this, the above-mentioned photosensitive material A is applied onto the intermediate substrate as a photopolymer material for holograms. The photosensitive material is applied by spin coating so that the thickness after drying is 5 μm. It will be distributed. Thereafter, the other intermediate substrate is placed in such a manner that its protective layer faces the protective layer of the intermediate substrate with the sealing layer. The adhesive is laminated on the sealing layer and the photosensitive material as shown in the figure, and then press-laminated under reduced pressure. The conditions were absolute pressure 5 kPa, temperature 70°C, and press pressure 0.04 MPa. After this, a diffraction grating is recorded on the photosensitive material of the press-bonded laminate. The temperature of the laminate is kept at 20°C. The diffraction grating is formed by irradiating the laminate with two laser beams. By adjusting the irradiation angle and intensity of each, interference is generated to form the desired diffraction pattern. This forms a diffraction grating on the photosensitive material. Specifically, the diffraction grating is a diffraction grating that detects red, green, and blue light incident as image light entering the incident portion. Each light in the wavelength range of the color is diffracted and emitted from the display unit at a position corresponding to the pixel of the image light. A diffraction grating for color display is formed. After this, while the laminate was kept at 20°C, it was irradiated with ultraviolet light (wavelength 365 nm, irradiance 80 W / cm 2 ) is irradiated from one side of the laminate for 30 seconds. A mercury lamp is used. As a result, the sealing layer is cured, and the light guide plate for image display 6 of Example 4 is produced.

[0075] [Example 5] In Example 5, the intermediate 2 is used to produce the light guide plate 6 for image display according to the embodiment. A light guide plate 6 for image display of Example 5 was produced in the same manner as in Example 4, except that the intermediate 2 was used. It is manufactured.

[0076] [Example 6] In Example 6, the intermediate 3 is used to produce a light guide plate 6 for image display according to the embodiment. A light guide plate 6 for image display of Example 6 was produced in the same manner as in Example 4 except that the intermediate 3 was used. It is manufactured.

[0077] Comparative Example 6 In Comparative Example 6, a light guide plate for image display was produced using Intermediate 4. A light guide plate for image display of Comparative Example 6 was prepared in the same manner as in Example 4, except that Intermediate 4 was used instead. 6 is produced.

[0078] Comparative Example 7 In Comparative Example 7, a light guide plate for image display was produced using Intermediate 5. A light guide plate for image display of Comparative Example 7 was prepared in the same manner as in Example 4, except that Intermediate 5 was used instead. 6 is produced.

[0079] <Evaluation method> Next, the evaluation method for each manufacturing example will be described. The evaluation was carried out by evaluating the clarity of the displayed image. It will be held.

[0080] [Evaluation of display image clarity] As a sample for measuring the clarity of the displayed image, a sample without the heat and humidity test (referred to as " in Table 2) The clarity of the measurement sample is measured in the same manner as in the embodiment. Each measurement sample is assembled into the above-mentioned display device. do. The clarity of the displayed image was evaluated using a luminance meter BM-8 (product name: manufactured by Topcon Corporation). can be. A white image and a character display image are used as input images for evaluation. The evaluation is carried out by visually determining how the white image and the character display image look. The character image displayed is "ABCDE" within a 10mm x 100mm area. If the rainbow color is not visible in the white image and the characters are clearly visible in the character display image, The clarity is good and there are no problems with the displayed image (marked "A" in Table 2). If the text is clearly visible but rainbow colors are visible in the white image, the displayed image is unusable. However, the image quality is judged to be poor (marked as "B" in Table 2). Rainbow colors are visible in the white image, and the outlines of the characters appear blurred in the text display image. If so, the displayed image is deemed unusable (denoted as "C" in Table 2). The measurement sample was subjected to the above-described humidity and heat durability test, and then the same clarity evaluation was performed. (In Table 2, this is referred to as "after the humidity and heat durability test").

[0081] Table 2 below shows the evaluation results of each example and comparative example.

[0082] [Table 2]

[0083] <Evaluation results> As shown in Table 2, the clarity of the displayed image in Examples 4 to 6 was good both initially and after the humidity and heat durability test. In both cases, the results are good and it can be determined that there are no problems with the displayed image. The clarity of the displayed images in Examples 6 and 7 can be judged to be inferior to that of the respective Examples.

[0084] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments. The present invention is not limited to the above embodiments and examples. , omissions, substitutions, and other modifications are possible. Furthermore, the present invention is not limited by the above description, but is encompassed by the appended claims. is limited only by [Industrial Applicability]

[0085] The light guide plate for image display of the present invention suppresses an increase in haze even in a humid and hot environment, and displays a clear image. This makes it useful for display devices for VR and AR applications, for example. For example, the light guide plate for image display of the present invention can be used in head-up displays, wearable displays, etc. It is useful for display device applications such as head-mounted displays and video players. [Explanation of symbols]

[0086] 1 First resin base material 22 1st protective layer 3 Hologram Layer 3a Display surface 3b Waveguide diffraction grating section 3c Diffraction grating section for display 24 Second protective layer 5 Second resin base material 6 Light guide plate for image display 6a Inlet section 6d display 10 Display device 12 Input optical system 13 Image light projection unit 14 Luminance meter 15 Measuring equipment 22A 1st organic material layer 22B 1st inorganic material layer 24A 2nd organic material layer 24B 2nd inorganic material layer

Claims

1. A light guide plate for image display, comprising a first resin substrate, a first protective layer containing a (meth)acrylic resin including a repeating unit derived from a polyfunctional (meth)acrylate, and a hologram layer, arranged in this order in a thickness direction, wherein an increase in haze of the first protective layer after 500 hours in an environment of 85°C and 85% RH is 0.1% or less, and a surface water contact angle of the first protective layer at 23°C is 70 degrees or less, the first protective layer comprises a first organic material layer that is a cured product of a (meth)acrylic resin composition that includes a matrix resin component containing a polyfunctional (meth)acrylate and a compound having one or more double bonds in the molecule and having a perfluoroalkenyl group, the compound is a leveling agent, The light guide plate for image display, wherein the content of the leveling agent in the (meth)acrylic resin composition is 0.3 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the matrix resin component.

2. 2. The light guide plate for image display according to claim 1, wherein the first protective layer has a thickness of 1 [mu]m or more and 15 [mu]m or less.

3. 3. The light guide plate for image display according to claim 1, wherein the first protective layer further comprises a first inorganic material layer.

4. 4. The light guide plate for image display according to claim 3, wherein the first inorganic material layer contains at least one inorganic material selected from the group consisting of silicon oxide, silicon nitride, silicon nitride oxide, silicon sulfide, aluminum oxide, aluminum nitride, aluminum nitride oxide, and aluminum sulfide.

5. 4. The light guide plate for image display according to claim 3, wherein the thickness of the first inorganic material layer is 50 nm or more and 5000 nm or less.

6. 6. The light guide plate for image display according to claim 1, wherein the hologram layer is made of a single or volume hologram material.

Images