JP2023132986A - Light guide plate for image display - Google Patents

Abstract

To provide an image display light guide plate which can suppress increase of haze even in a moist heat environment and can hold a clear image.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 protection layer includes a first organic material layer, which is a cured material of a mixture including a matrix resin component containing a polyfunctional (meth)acrylate and an additive having an at least one double binding in a molecule.SELECTED DRAWING: None

Description

The present invention relates to a light guide plate for image display.

In a display device, a light guide plate for image display is sometimes used. For example, VR (Virtual Reality) technology or AR (Augmented Reality)
In a display device using Reality technology, a light guide plate for displaying an image in which a hologram layer is supported by a transparent base material is used.

Although a glass substrate is often used as the transparent substrate, studies have been made to change the transparent substrate from glass to plastic for the purpose of reducing weight and improving safety.

For example, Patent Document 1 discloses a hologram laminate used in a vehicle head-up display. This hologram laminate includes an acrylic resin substrate, an acrylic adhesive layer, a hologram layer made of an acrylic photopolymer, an acrylic adhesive layer, and an acrylic resin substrate, which are laminated in this order. Further, Patent Document 1 describes that the appearance of the hologram changes depending on the surface smoothness of the acrylic resin substrate, and when the maximum height Rmax representing the surface smoothness of the hologram laminate exceeds 50 μm, The change in the appearance of the hologram becomes noticeable. On the other hand, when the maximum height Rmax is less than 25 μm, the change in the appearance of the hologram is within an acceptable range.

The structure of a transparent resin base material such as the acrylic resin base mentioned above is such that a resin hard coat layer is provided on the highly transparent resin base material for the purpose of preventing scratches and improving chemical resistance, and a hologram layer is added to the resin base material. A gas barrier layer is preferably provided for the purpose of preventing moisture absorption. Furthermore,
A leveling agent is generally added to such a hard coat layer in order to improve smoothness.

Japanese Patent Application Publication No. 2000-296583

However, such a leveling agent may cause a phenomenon of bleeding onto the surface in a high temperature and high humidity environment. Changes in the surface condition may increase haze, which may lead to a decrease in brightness when displaying images. Patent Document 1 does not mention changes in the surface properties of the hologram laminate under a moist heat environment.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a light guide plate for image display that uses a resin base material and has excellent wet heat durability. .

In view of this situation, the present inventors focused on the fact that the polyfunctional (meth)acrylate that is the hard coat layer is a resin material that hardens through a radical polymerization reaction caused by UV irradiation, and created a double bond in the molecule. A leveling agent was used. By chemically bonding the leveling agent and acrylate during curing, it was possible to suppress the leveling agent from bleeding onto the surface even in high temperature and high humidity environments, and it was possible to suppress an increase in haze.
The present invention has the following aspects.
[1] Contains a first resin base material and a repeating unit derived from polyfunctional (meth)acrylate (meth)
A light guide plate for image display in which a first protective layer containing an acrylic resin and a hologram layer are arranged in this order in the thickness direction, wherein A light guide plate for image display, which has a haze increase of 0.1% or less after a period of time.
[2] The first protective layer is a cured product of a (meth)acrylic resin composition containing a matrix resin component containing a polyfunctional (meth)acrylate and a compound having one or more double bonds in the molecule. The light guide plate for image display according to [1], comprising a certain first organic material layer.
[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 0.01 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the matrix resin component, [3]
Light guide plate for image display.
[5] The light guide plate for image display according to any one of [1] to [4], wherein the first protective layer has a thickness of 1 μm or more and 15 μm or less.
[6] The light guide plate for image display according to any one of [1] to [5], wherein the first protective layer further includes a first inorganic material layer.
[7] The first inorganic material layer is silicon oxide, silicon nitride, silicon nitride oxide, silicon sulfide,
The image display light guide plate according to any one of [1] to [6], comprising at least one inorganic material selected from the group consisting of aluminum oxide, aluminum nitride, aluminum nitride oxide, and aluminum sulfide.
[8] The thickness of the first inorganic material layer is 50 nm or more and 5000 nm or less, [1] to [7]
] Any of the image display light guide plates.
[9] The hologram layer is made of a single or volume hologram material, [1] to [8]
A light guide plate for image display.

According to the present invention, it is possible to provide a light guide plate for image display that has excellent wet heat durability.

FIG. 1 is a schematic cross-sectional view showing an example of an image display light guide plate according to an embodiment of the present invention. FIG. 2 is a schematic front view illustrating a method for measuring brightness values and FOV.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In all drawings, even if the embodiments are different, the same or corresponding parts are denoted by the same reference numerals.
Common explanations will be omitted.
A numerical range expressed using “~” includes the numbers at both ends of “~”.
"UV" means ultraviolet light.
"(Meth)acrylic" means one or both of acrylic and methacrylic.
"(Meth)acrylate" means one or both of acrylate and methacrylate.

<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 image display light guide plate of this embodiment has a first resin base material, a first protective layer, and a hologram layer. The first resin base material, the first protective layer, and the hologram layer are arranged in this order in the thickness direction. The first protective layer is
It has a first organic material layer and can also have a first inorganic material layer if necessary. The first protective layer may be disposed on at least one surface of the hologram layer, but the second protective layer and the second protective layer may be disposed on the other surface of the hologram layer in this order in the thickness direction of the second resin base. A protective layer may be arranged on the surface. In this case, the hologram layer is sandwiched between the first protective layer and the second protective layer, the first resin base material is laminated on the other surface of the first protective layer, and the second protective layer A second resin base material is laminated on the other surface. In this embodiment, the first resin base material and the second resin base material may be collectively referred to as simply "resin base material" hereinafter. Further, the first protective layer and the second protective layer may be collectively referred to as simply "protective layer" hereinafter. Further, the first organic material layer and the second organic material layer may be collectively referred to as simply "organic material layer" hereinafter. Further, the first inorganic material layer and the second inorganic material layer may be collectively referred to as simply "inorganic material layer" hereinafter.
FIG. 1 is a schematic cross-sectional view showing an example of an image display light guide plate according to a modification of the embodiment of the present invention.

One or more transparent layers are arranged between the first resin base material and the first organic layer, between the first organic material layer and the second inorganic material layer, and between the first inorganic layer and the hologram layer. You can leave it there. Examples include an adhesive layer, a hard coat layer, and an anchor coat layer.

The image display light guide plate has an entrance portion into which image light is incident, and a display portion which displays an image using the image light. The hologram layer is arranged between the incident part and the display part. The hologram layer is formed with a diffraction grating pattern for guiding at least image light incident from the incident portion to the display portion and emitted from the display portion. The diffraction grating pattern in the display section transmits at least a portion of external light incident from outside the image display light guide plate. Note that external light enters from the surface opposite to the display section.

The image light that has entered the incident section is guided into the hologram layer, and is emitted from the display section to the outside. On the other hand, since external light also passes through the resin base material and the display section, an observer of the display section can observe both the image light and the external light within his/her field of view.
The image display light guide plate of this embodiment is suitably used for display devices using VR technology, AR technology, and the like. For example, in addition to display applications, the image display light guide plate of this embodiment can be used for hologram optical elements (HOEs), such as combiners for automotive heads-up displays (HUDs) and reflectors for reflective liquid crystal display devices. ) may be used in devices such as

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

In the image display light guide plate 6 shown in FIG. 1, in the thickness direction, the first resin base 1, the first organic material layer 22A, the first inorganic material layer 22B, the hologram layer 3, the second inorganic material layer 24B, The organic material layer 24A and the second resin base material 5 are arranged in this order.
The shape of the image display light guide plate 6 in plan view is not particularly limited. For example, the image display light guide plate 6
may be shaped into a shape that can be attached to a display device to be used.
For example, the image display light guide plate 6 may be a rectangular plate larger than the shape to be attached to the display device. In this case, the image display light guide plate 6 is molded by cutting into a shape that can be attached to the display device before being assembled into the display device.
The image display light guide plate 6 may be in the shape of a flat plate, or may be in the shape of a curved plate if necessary.
In the following, an example will be described in which the image display light guide plate 6 is made of a flat plate having a rectangular shape in plan view.

[First resin base material 1]
The first resin base material 1 is arranged at the outermost part of the image display light guide plate 6 in the thickness direction. The first resin base material 1 is arranged on the surface of the image display light guide plate 6 on the display image output side.
The first resin base material 1 has a shape similar to the outer shape of the image display light guide plate 6.
The first resin base material 1 receives the image light emitted from the hologram layer 3 and the 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 greater than or equal to mm and less than or equal to 10 mm.
In this specification, the thickness of the first resin base material 1 can be measured using a dial gauge method using a stylus, a micrometer, or the like.

As the material forming the first resin base material 1, any known transparent resin material can be used without particular limitation.
Considering optical properties such as transparency and refractive index of light, as well as main physical properties such as impact resistance, heat resistance, and durability, we Polyolefin resins; amorphous polyolefin resins such as cyclic polyolefin resins; polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); cellulose resins such as triacetyl cellulose, diacetyl cellulose, and cellophane; nylon 6 , nylon 66, nylon 12, polyamide resins such as copolymerized nylon; ethylene-vinyl acetate copolymer partial hydrolyzate (EVOH), polyimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins Resin, polyetheretherketone resin, polycarbonate resin, polyvinyl butyral resin, polyarylate resin, fluororesin, poly(meth)acrylic resin, styrene resin such as polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, PVC,
Organic materials such as cellulose, acetyl cellulose, polyvinylidene chloride, polyphenylene sulfide, polyurethane, phenolic resin, epoxy resin, polynorbornene, styrene-isobutylene-styrene block copolymer (SIBS), allyl diglycol carbonate, biodegradable resin, etc. Can be mentioned. Note that the first resin base material 1 may be formed of two or more types of materials, or may have a laminated structure in which two or more types of materials are laminated.
From the viewpoint of transparency, it is more preferable to use polycarbonate resin, poly(meth)acrylic resin, or the like. Further, from the viewpoint of process resistance, it is more preferable to use poly(meth)acrylic resin, epoxy resin, cyclic polyolefin resin, or the like.

[First organic material layer 22A]
The first organic material layer 22A contains a (meth)acrylic resin containing repeating units derived from polyfunctional (meth)acrylate. By arranging the first organic material layer 22A on the surface of the first resin base material 1, deterioration of the first resin base material 1 due to the hologram layer 3 can be prevented, so there are a number of options for materials that can be used for the first resin base material 1. can be increased.

The (meth)acrylic resin of the first organic material layer 22A may contain repeating units derived from various polyfunctional (meth)acrylates, and may not contain repeating units derived from monofunctional various (meth)acrylates. You can stay there.
Polyfunctional (meth)acrylate means a (meth)acrylate having two or more radically polymerizable functional groups in the molecule.
Examples of polyfunctional (meth)acrylates that are raw materials for (meth)acrylic resins include:
Polyfunctional (meth)acrylate such as polyethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tricyclodidecane dimethanol di(meth)acrylate, etc. ) acrylates.
Examples of monofunctional (meth)acrylates include isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, butoxyethyl (meth)acrylate, and lauryl (meth)acrylate. ) acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, hexyl diglycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, phenoxyethyl (meth)acrylate, ) acrylate, dicyclopentadiene (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, nonylphenoxyethyl cellosolve (meth)acrylate, and the like.
These (meth)acrylates may be used alone or in combination of two or more to form a copolymer.

Moreover, in addition to the above-mentioned (meth)acrylic resin, an oligomer made of the above-mentioned polyfunctional (meth)acrylate may be contained. Examples include oligourethane (meth)acrylate, oligoester (meth)acrylate, and the like.

The (meth)acrylic resin has a repeating unit derived from a polyfunctional (meth)acrylate, so it can have a crosslinked structure, so it does not swell with the hologram material, has chemical resistance, and has long-term visibility. A light guide plate having excellent properties can be obtained.
The method of forming the first organic material layer 22A is not particularly limited. For example, it is formed by applying a (meth)acrylic resin composition containing polyfunctional (meth)acrylate as a matrix resin component to the surface of the first resin base material, and then curing the (meth)acrylic resin composition. can.
Examples of coating methods for the (meth)acrylic resin composition include air doctor coating, blade coating, knife coating, reverse coating, transfer roll coating, gravure roll coating, kiss coating, cast coating, spray coating, and slot orifice coating. , coating methods such as calendar coating, electrodeposition coating, dip coating, and die coating; letterpress printing methods such as flexographic printing, intaglio printing methods such as direct gravure printing method and offset gravure printing method, and lithographic printing methods such as offset printing method; Examples include printing methods such as stencil printing methods such as screen printing methods.

The (meth)acrylic resin composition may be diluted with various solvents as necessary for the purpose of adjusting viscosity and improving coatability. Various general organic solvents can be used as such diluting solvents, such as alcohol compounds such as methanol, ethanol, 1-propanol, and 2-propanol; ketone compounds such as acetone and methyl ethyl ketone;
Examples include ester compounds such as ethyl acetate, propyl acetate, and butyl acetate; aromatic compounds such as toluene and xylene. These diluting solvents can be used alone or in combination of two or more.

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

In addition to the matrix resin component, various additives may be added to the (meth)acrylic resin composition for the purpose of imparting more excellent characteristics to the image display light guide plate of the present invention.
As additives, viscosity modifiers, coating property improvers, leveling agents, ultraviolet absorbers, antioxidants, anti-scratch agents, etc. can be blended as appropriate, and are not particularly limited. It is preferable to use a leveling agent because imparting high smoothness to the protective layer tends to improve the optical properties, durability, etc. of the light guide plate for image display of the present invention.

On the other hand, these additives are preferably compounds having one or more double bonds in the molecule that can chemically bond to the matrix resin component during curing of the (meth)acrylic resin composition.
By using a cured product of a (meth)acrylic resin composition containing such a compound as an additive as the first organic material layer, the additive bleeds out from the first protective layer even in a high temperature and high humidity environment. 85° C. in the light guide plate for image display of the present invention.
, 85% RH, and 500 hours of haze increase can be made 0.1% or less.
Therefore, suitable examples of the leveling agent include acrylic leveling agents, silicone leveling agents, and fluorine leveling agents. Specific examples include acrylate polymers and oligomers containing polyether, alkyl, polyester, etc. in their side chains;
silicone polymers and oligomers having silicone chains and polyalkylene oxide chains; silicone polymers and oligomers having silicone chains and polyester chains;
Examples include fluoropolymers and oligomers having a perfluoroalkyl group and a polyalkylene oxide chain, and fluoropolymers and oligomers having a perfluoroalkyl ether chain and a polyalkylene oxide chain, but for the reasons mentioned above, K
Silicone polymers and oligomers with ethylenically unsaturated groups, such as the P series (manufactured by Shin-Etsu Silicone Co., Ltd.) and Polyflow KL series (manufactured by Kyoeisha Chemical Co., Ltd.), or the Megafac RS series (manufactured by DIC Corporation), KY400 series (manufactured by DIC Corporation), etc. Fluoropolymers and oligomers such as Shin-Etsu Silicone Co., Ltd.) and Ftergent series (Neos Co., Ltd.)
It is preferable to use a compound having one or more double bonds in its molecule that can chemically bond to the matrix resin component.

Moreover, these leveling agents are added in an amount of 0.00 parts by weight per 100 parts by mass of the matrix resin component.
It is preferable to use it in a range of 0.01 parts by mass or more and 2 parts by mass or less.
By setting the blending amount of the leveling agent to 0.01 part by mass or more, the smoothness and scratch resistance of the first protective layer can be improved without polishing it, and the processing is useful as a light guide plate for displaying polished images. Accuracy tends to be easily obtained. More preferably, it is 0.1 part by mass or more. Furthermore, by controlling the amount of the leveling agent to 1 part by mass or less, sufficient transparency and mechanical strength can be obtained as a light guide plate for image display, and it tends to be possible to suppress an increase in haze under high temperature and high humidity environments. be. More preferably, it is 1 part by mass or less.

Further, a silane coupling agent may be added to the acrylic resin composition to adjust the adhesion between the first organic material layer 22A and the first resin base material. That is, a silane coupling agent can be used for the purpose of strengthening the adhesion between the first organic material layer 22A and the first resin base material.
A typical example of the silane coupling agent is an aminosilane compound. Specific examples of aminosilane compounds include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, and γ-aminopropyltriethoxysilane. -N-phenylaminopropyltrimethoxysilane is mentioned. These aminosilanes can be used alone or in a mixture of two or more. Furthermore, coupling agents other than aminosilane may be used in combination.

The thickness of the first protective layer 2 including the first organic material layer 22A is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 5 μm or more. When the thickness of the first protective layer 2 is 1 μm or more, deterioration of the resin base material due to the hologram layer 3 can be prevented. Further, the thickness of the first protective layer 2 is preferably 15 μm or less;
It is more preferably 2 μm or less, and even more preferably 10 μm or less. When the thickness of the first protective layer 2 is 15 μm or less, the elastic modulus of the first protective layer 2 can be increased.
Note that the thickness of the first protective layer 2 can be measured using a non-contact optical interference type film thickness meter or the like.

The elastic modulus of the first organic material layer 22A is preferably 2 GPa or more, more preferably 5 GPa or more. When the elastic modulus is 2 GPa or more, deterioration of the resin base material due to the hologram layer 3 can be prevented. Moreover, it is preferable that the elastic modulus of 22 A of 1st organic material layers is 20 GPa or less, and it is more preferable that it is 15 GPa or less. Elastic modulus is 20GPa
By being below, it is possible to suppress warping due to curing shrinkage during formation of the organic layer.
The elastic modulus can be measured using a measuring device: Shimadzu dynamic ultra-microhardness meter, DUH-W201, measuring conditions: Triangular 115, indentation depth of 230 to 280 nm.

Further, the difference in refractive index between the first resin base material 1 and the first organic material layer 22A is preferably 0.3 or less, more preferably 0.2 or less. By having a refractive index difference of 0.3 or less, an excellent brightness value can be provided and color unevenness can be prevented.
Note that the refractive index can be measured by a commonly used method using an Abbe refractometer or an ellipsometer.

[First inorganic material layer]
The first inorganic material layer 22B can be appropriately employed 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, the first resin base material, the first organic material layer, the first inorganic material layer, and the hologram layer are arranged in the thickness direction.
They can be arranged in this order. In this case, it is preferable that the first inorganic material layer and the hologram layer are in direct contact because the ability to prevent moisture absorption into the hologram layer is higher and the deterioration of the resin base material due to the hologram layer tends to be prevented.
Examples of the inorganic material used for the first inorganic material layer 22B include silicon oxide, silicon nitride, silicon nitride oxide, silicon sulfide, aluminum oxide, aluminum nitride, aluminum nitride oxide, and aluminum sulfide.
Among these, silicon oxide, silicon nitride oxide, aluminum oxide, and aluminum nitride oxide are preferred from the viewpoint of improving total light transmittance and barrier properties. In particular, it is preferable that the content of alkali oxide components such as sodium and potassium is low because it is possible to suppress deterioration of barrier properties under high temperature and high humidity conditions.

The thickness of the first inorganic material layer 22B is preferably 50 nm or more and 5000 nm or less, and 50 nm or more and 5000 nm or less.
The thickness is more preferably 3000 nm or less. When the layer thickness is 50 nm or more, a sufficient effect of preventing moisture absorption into the hologram layer can be obtained, and sufficient hologram agent resistance tends to be obtained. Further, since the layer thickness is 5000 nm or less, cracks are less likely to occur in the protective layer 22, and therefore delamination can be suppressed. A particularly preferable layer thickness is 50n
m or more and 1000 nm or less.

The inorganic material used for the first inorganic material layer 22B may have a higher refractive index 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 is 1.4.
It may be 8 or more and 3.0 or less. When the first inorganic material layer 22B has a high refractive index, the light that passes through the first resin base material 1 via the first protective layer 22 is optically transmitted from the optically dense first inorganic material layer 22B. The light passes through the rough first organic material layer 22A and enters the first resin base material 1. Therefore,
The emission angle of light directed from the first protective layer 22 toward the first resin base material 1 increases according to the difference in refractive index between the first protective layer 2 and the first resin base material 1. As a result, the FOV (
field of view).

The method of forming the first inorganic material layer 22B is not particularly limited. For example, it can be formed by any conventionally known method such as a vacuum evaporation method, a sputtering method, an ion plating method, or a plasma CVD method. When forming the first inorganic material layer 22B using silicon oxide, in order to improve the adhesion between the film-forming surface and the silicon oxide, the film-forming surface may be subjected to corona discharge treatment or low-temperature plasma treatment, or Surface treatment such as coating with a silane coupling agent or a mixture of saturated polyester and isocyanate may be performed.
For example, when forming a thin film of silicon oxide by vacuum evaporation, silicon, silicon monoxide, silicon dioxide, or a mixture thereof is used as the evaporator, and the temperature is 1.0×10 ⁻³ Torr to
The material is heated and evaporated under a vacuum of 1.0×10 ⁻⁵ Torr using an electron beam, resistance heating, or high frequency heating method. Further, a reactive vapor deposition method performed while supplying oxygen gas can also be adopted.
When forming a layer made of silicon nitride oxide as the first inorganic material layer 22B, it is the same as the first inorganic material layer 22B mainly composed of silicon oxide, except that silicon oxide is replaced with silicon nitride oxide. The following configuration is used.

When forming a layer made of aluminum oxide as the first inorganic material layer 22B, for example,
It may be formed of only Al ₂ O ₃ or may be formed of a mixture of Al, AlO, Al ₂ O ₃ , etc. The atomic ratio of Al:O in the aluminum oxide layer varies depending on the conditions for producing the aluminum oxide layer. The aluminum oxide layer that can be used as the first inorganic material layer 22B may contain a trace amount (up to 3% of all components) of other components as long as the density performance is not impaired.
The thickness of the aluminum oxide layer may be set according to needs such as chemical resistance. For example, the thickness of the aluminum oxide layer may be 5 nm or more and 800 nm or less.

The method of forming the first inorganic material layer 22B using aluminum oxide is not particularly limited. For example, the first inorganic material layer 22B may be formed using a PVD method (physical vapor deposition method) such as a vacuum deposition method, a sputtering method, or an ion plating method, or a CVD method (chemical vapor deposition method).
For example, in the vacuum evaporation method, Al, Al ₂ O ₃ , etc. are used as the evaporation source material, and resistance heating, high frequency induction heating, electron beam heating, etc. may be used as the heating method for the evaporation source. . In the vacuum evaporation method, oxygen, nitrogen, water vapor, etc. are introduced as reactive gases,
Reactive vapor deposition using means such as ozone addition and ion assist may also be used. Furthermore, a bias or the like may be applied to the substrate on the film-forming surface, or the temperature of the film-forming surface may be increased or cooled. The same applies to other film forming methods such as sputtering and CVD.

[Hologram layer 3]
The hologram layer 3 is laminated on the surface of the first protective layer 2. The configuration of the hologram layer 3 is not particularly limited. A suitable diffraction grating corresponding to the functions necessary for the image display light guide plate 6 is formed in the hologram layer 3.
The material of the hologram layer 3 is not particularly limited, and may be a known hologram-forming resin material.
For example, hologram recording materials (JP-A No. 9-62169, JP-A-11-1999) made of a thermosetting resin that is solvent-soluble and has at least one cationically polymerizable ethylene oxide ring in its structural unit, and a radically polymerizable ethylenic monomer Publication No. 161141, Japanese Patent Application Publication No. 2
002-310932).
Specifically, epoxy resins such as bisphenol-based epoxy resins; (meth)acrylates such as triethylene glycol diacrylate; photopolymerization initiators such as 4,4'-bis(tert-butylphenyl)iodonium hexafluorophosphate; It is preferably formed from a photosensitive material containing a wavelength sensitizer such as 3,3'-carbonylbis(7-diethylamino)coumarin; and an organic solvent such as 2-butanone.
Among these, it is preferable that the hologram layer is made of a single or volume hologram material.

[Second inorganic material layer 24B]
The second inorganic material layer 24B is a part of the second protective layer 24, and the second inorganic material layer 24B is a part of the second protective layer 24.
It is laminated on the opposite side of the protective layer 2. As the second inorganic material layer 24B, the first inorganic material layer 2
A configuration similar to that illustrated in the description of 2B is used. However, the second inorganic material layer 2
The thickness, material, etc. of 4B may be different from those of first inorganic layer 22B.

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

[Second resin base material 5]
The second resin base material 5 is laminated on the surface of the second protective layer 24. As the second resin base material 5, a configuration similar to that exemplified in the description of the first resin base material 1 is used. However, the second
The thickness, material, etc. of the resin base material 5 may be different from those of the first resin base material 1. In particular, since the second resin base material 5 is disposed on the surface of the image display light guide plate 6 on the external light incident side opposite to the display image output side, the surface hardness is lower than that of the first resin base material 1. High quality materials may be used.

[Light guide plate 6 for image display]
The image display light guide plate 6 is provided between the first resin base material 1 and the hologram layer 3 and between the second resin base material 5
A first protective layer 22 and a second protective layer 24 are arranged between 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, and the second protective layer 24 includes a second organic material layer 24A and a second inorganic material layer 24B.
In the first protective layer 22, it is preferable that the first organic material layer 22A is disposed on the first resin base material 1 side, and the first inorganic material layer 22B is disposed on the hologram layer 3 side. In addition, the second protective layer 24
Also, it is preferable that the second organic material layer 24A is disposed on the second resin base material 2 side, and the second inorganic material layer 24B is disposed on the hologram layer 3 side.
Although 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, it is much lower than that of glass. Therefore, the first resin base material 1 and the second resin base material 5 have lower solvent resistance and hologram material resistance than glass.
When the first resin base material 1 and the second resin base material 5 are in contact with the hologram layer 3, the hologram agent, which is a component of the hologram layer 3, passes through the first resin base material 1 and the second resin base material 5. or
The hologram agent tends to accumulate inside the first resin base material 1 and the second resin base material 5. When the first resin base material 1 and the second resin base material 5 are exposed to the hologram agent, the first resin base material 1 and the second resin base material 5 are likely to deteriorate, resulting in a decrease in clarity and the like.
Therefore, between the first resin base material 1 and the second resin base material 5 and the hologram layer 3, the first
By providing the protective layer 2 and the second protective layer 4, the penetration of the hologram agent into the first resin base material 1 and the second resin base material 5 is suppressed, thereby preventing deterioration of the resin base material.

<Method for manufacturing light guide plate for image display>
The image display light guide plate 6 can be manufactured, for example, as follows.
A first resin base material 1 and a second resin base material 5 are prepared ([substrate preparation step]), and the first resin base material 1
A first organic material layer 22A and a second organic material layer 24A are respectively formed on the surface of the second resin base material 5 ([organic material layer forming step]). A first inorganic material layer 22B and a second
Inorganic material layers 24B are respectively formed (inorganic material layer forming step).
A photosensitive material for forming a hologram is applied to the surface of the first inorganic material layer 22B. At this time, a transparent sealing layer having the same thickness as the hologram layer 3 may be provided on the outer periphery of the first inorganic material layer 22B. In this case, the photosensitive material is applied to the formed recess surrounded by the sealing layer. The sealing layer seals the outer periphery of the hologram layer 3 after the hologram layer 3 is formed.
After that, the second resin base material 5 on which the second protective layer 24 is formed is placed on the photosensitive material.
4 is placed facing the photosensitive material ([light guide plate manufacturing process]).
After that, the first resin base material 1, the first protective layer 2, the hologram layer 3, and the second
A laminate consisting of 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 on the photosensitive material of the laminate, and
Form a diffraction grating.
In this way, the image display light guide plate 6 is manufactured.

When the inorganic material is silicon oxide, the inorganic material layer can be formed as follows.
After the intermediate body consisting of the resin base material and the organic material layer is placed in a vacuum evaporation apparatus, silicon oxide is vacuum evaporated. The ultimate vacuum degree of the chamber of the vacuum evaporation apparatus is preferably 3×10 ⁻³ Torr or less. Under this vacuum, silicon monoxide with a purity of 99.9% is heated and evaporated using a high-frequency induction heating method to form a silicon oxide thin film on the surface of the resin base material. As a result, an intermediate laminate on which a silicon oxide thin film layer is formed is obtained.
After that, the image display light guide plate 6 is formed.

When the inorganic material is alumina, the inorganic material layer can be formed as follows.
An intermediate body consisting of a resin base material and an organic material layer is placed in an electron beam evaporation device, and an appropriate amount of alpha alumina particles with a purity of 99.999% and a particle size of 0.5 to 5 mm are placed as a evaporation source, and then vacuum evacuated. I do. The distance from the vapor deposition source to the shutter is preferably about 3 to 15 cm, and the distance from the vapor deposition source to the surface of the resin substrate is preferably about 5 to 50 cm.
After the pressure of the electron beam evaporator reaches 3×10 ⁻³ Torr or less, the filament current of the electron beam is increased to 25 to 50 mA, the shutter is opened, and alumina film is formed. When the temperature of the wall inside the device reaches 45°C or higher, the shutter is closed and the filament current of the electron beam is stopped. After cooling to 35° C. or lower, the filament current of the electron beam is increased to 25 to 50 mA to heat the evaporation source, the shutter is opened, and alumina film is formed. This is repeated to form an alumina film. As a result, an intermediate laminate having an alumina thin film layer formed thereon is obtained.
After that, the image display light guide plate 6 is formed.

<Brightness value>
Here, an example of a method for measuring the brightness value in the image display light guide plate 6 will be briefly described.
FIG. 2 is a schematic front view illustrating a method for measuring brightness values.

As shown in FIG. 2, in order to measure the brightness value of the image display light guide plate 6, the image display light guide plate 6
The display device 10 is manufactured using the method.
In addition to the image display light guide plate 6, the display device 10 includes an image light projection section 13 and an incident optical system 12.
Equipped with
The image light projection unit 13 projects image light to be displayed on the image display light guide plate 6 in response to an image signal sent from a controller (not shown).
The entrance optical system 12 includes, for example, a prism. The entrance optical system 12 makes the image light emitted from the image light projection section 13 enter the entrance section 6a provided on the surface of the image display light guide plate 6. For example, the incident part 6a is provided on the surface of the resin base material 1 side.
The image light incident on the incident part 6a reaches the display diffraction grating part 3c of the hologram layer 3 via the waveguide diffraction grating part 3b formed in the hologram layer 3. The display diffraction grating section 3c diffracts the image light at a position corresponding to each display pixel. The diffracted light is emitted to the outside from the display section 6d on the surface of the image display light guide plate 6. In the example shown in FIG. 2, the display section 6d is formed on the surface of the resin base material 1 at a position spaced apart from the incident section 6a.

The luminance value of the image display light guide plate 6 is measured by placing the display device 10 in the measuring device 15.
The measuring device 15 includes a holding table (not shown), a luminance meter 14, a goniometer stage (not shown),
Equipped with
The holding stand holds the display device 10. The brightness meter 14 measures the brightness value of the received light. The goniometer stage swingably supports the luminance meter 14 on a circumference centered on its rotation center.
The distance d between the luminance meter 14 and the display surface 3a corresponds to 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 assumed to be 15 mm.

The brightness value of the image display light guide plate 6 is measured by placing the brightness meter 14 at a position where the swing angle is 0° (see the solid line brightness meter 14 in FIG. 2). The display device 10 is mounted on the display surface 3 by the holding base.
The center of a is placed at a position facing the brightness meter 14 on the measurement optical axis of the brightness meter 14.
The brightness value is the brightness measured by the brightness meter 14 when the display device 10 displays a white image with maximum brightness.
The brightness value is preferably 1000 nits or more, more preferably 1200 nits or more.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Production Examples. The present invention is not limited to these Examples and Production Examples.

[Example 1]
The material for the resin base material is PMMA (“Acrylite (registered trademark)” manufactured by Mitsubishi Chemical Corporation).
) is used. The resin base material is a rectangular plate with a width of 60 mm, a length of 60 mm, and a thickness of 1 mm.

[Substrate preparation process]
In the substrate preparation step, the resin base material is cleaned and dried.
The resin base material is ultrasonically cleaned for 5 minutes while immersed in a 5% surfactant aqueous solution of Semi-Clean (registered trademark) M-LO (trade name; manufactured by Yokohama Yushi Kogyo Co., Ltd.), which is a neutral cleaning agent. .
Thereafter, the resin base material is ultrasonically cleaned for 5 minutes while immersed in ultrapure water. Furthermore, the resin base material is rinsed with ultrapure water, and after air drying, the resin base material is dried in an oven at 80° C. under a nitrogen atmosphere. After that, the air-dried evaluation sample B was exposed to UV ozone for 1 minute in a UV ozone cleaner.
Clean with ozone.
With this, the substrate preparation process is completed.

[Organic material layer formation process]
In the organic material layer forming step, an organic material layer is formed on the surface of the resin base material.
Omnirad 184 as an initiator to 100 parts by mass of Shiko 7600B (manufactured by Mitsubishi Chemical Corporation, isophorone diisocyanate/pentaerythritol triacrylate)
(manufactured by IGM Resins) and Polyflow KL402 (manufactured by IGM Resins) as a leveling agent.
0.1 part by mass of a silicone leveling agent (manufactured by Kyoeisha Chemical) was added, and MEK (methyl ethyl ketone, manufactured by Sankyo Chemical) and PGM (propylene glycol monomethyl ether acetate, manufactured by Sankyo Chemical) were mixed at a mass ratio of 7:3. A mixed solvent was used to adjust the solid content to 40% by mass to obtain a liquid mixture for an organic material layer. The above-mentioned liquid mixture is applied to the base resin using a bar coater, and irradiated with a high-pressure mercury lamp (integrated light amount: 500 mJ/cm ² ) to form an organic material layer having a thickness of 5 μm after curing.
With this, the organic material layer forming process is completed.

[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 base material on which the organic material layer is formed is placed in a vacuum evaporation apparatus, silicon oxide is vacuum evaporated. The ultimate vacuum degree of the chamber of the vacuum evaporation apparatus is 1.0×10 ⁻⁴ 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 with a thickness of 100 nm is formed on the surface of the organic material layer.
With this, the inorganic material layer forming step was completed, and intermediate 1 was obtained.
A product obtained by forming an organic material layer and an inorganic material layer in this order on a base resin by this operation is called an "intermediate".

[Example 2]
In Example 2, Intermediate 2 was obtained in the same manner as in Example 1, except that the added amount of Polyflow KL402, which is a leveling agent contained in the organic material layer, was 0.3 parts by mass.

[Example 3]
In Example 3, Intermediate 3 was obtained in the same manner as in Example 1, except that the amount of Polyflow KL402, which is a leveling agent contained in the organic material layer, was 0.5 parts by mass.

[Example 4]
In Example 4, the leveling agent contained in the organic material layer was Megafac RS75 (fluorine-based,
Intermediate 4 was obtained in the same manner as in Example 1, except that the amount was 0.1 part by mass (manufactured by DIC).

[Example 5]
In Example 5, the leveling agent contained in the organic material layer was Megafac RS75 (fluorine-based,
Intermediate 5 was obtained in the same manner as in Example 1, except that the amount was 0.3 parts by mass (manufactured by DIC).

[Example 6]
In Example 6, the leveling agent contained in the organic material layer was Megafac RS75 (fluorine-based,
Intermediate 6 was obtained in the same manner as in Example 1, except that the amount was 0.5 parts by mass (manufactured by DIC).

[Comparative example 1]
In Comparative Example 1, Intermediate 7 was obtained in the same manner as in Example 1, except that the leveling agent contained in the organic material layer was not added.

[Comparative example 2]
In Comparative Example 2, the leveling agent contained in the organic material layer was Polyflow PF75 (acrylic,
Intermediate 8 was obtained in the same manner as in Example 1, except that the amount was 0.5 parts by mass (manufactured by Kyoeisha Kagaku Co., Ltd.).

[Comparative example 3]
In Comparative Example 2, the leveling agent contained in the organic material layer was BYK361N (acrylic type, BY
Intermediate 9 was obtained in the same manner as in Example 1, except that the amount was 0.5 parts by mass (manufactured by Company K).

<Moist heat durability test>
In the moist heat durability test, the above intermediate was held at 85° C. and 85% RH for 500 hours using a small environmental tester SH-241 (trade name; manufactured by ESPEC Co., Ltd.).

<Measurement of haze>
For haze measurement, the intermediate was evaluated using a haze meter NDH7000II manufactured by Nippon Denshoku Kogyo Co., Ltd., and the haze difference (Δ haze) before and after the moist heat test was calculated.

<Presence or absence of double bond>
The presence or absence of double bonds in the leveling agent was determined based on the molecular structure provided by the manufacturer.

Table 1 shows the configuration and measurement results of each Example and each Comparative Example.

<Evaluation results>
As shown in Table 1, the haze change (“haze increase” in [Table 1]) before and after the heat-and-moisture test for Examples 1 to 6 was 0.1 or less, and it can be determined that the samples had excellent heat-and-moisture stability. On the other hand, the haze changes before and after the heat-and-moisture test of Comparative Examples 1, 2, and 3 exceeded 0.1, and it can be determined that none of them had excellent heat-and-moisture stability.
The reason for this is that in Examples 1 to 6, the leveling agent is chemically bonded to the polyfunctional acrylate that is the hard coat layer, so the leveling agent does not bleed to the surface even in a moist heat environment, resulting in an increase in haze. This can be said to be because it was able to suppress the
On the other hand, in Comparative Examples 1 to 3, the increase in haze was large, and in Comparative Examples 2 and 3 in particular, bleeding of the leveling agent occurred on the surface, causing a significant increase in haze.

Next, examples of light guide plates for image display using each of the above-mentioned intermediates will be described. The image display light guide plate can be manufactured by performing the light guide plate manufacturing process described below.

[Example 7]
In Example 7, the image display light guide plate 6 of the embodiment is manufactured using the intermediate body 1.
The photosensitive material for the hologram layer 3 is bisphenol-based epoxy resin jER (
(registered trademark) 1007 (degree of polymerization n = 10.8, epoxy equivalent: 1750-2200, manufactured by Mitsubishi Chemical) 100 parts by mass, 50 parts by mass of triethylene glycol diacrylate, and 4,4
A mixture of 5 parts by mass of '-bis(tert-butylphenyl)iodonium hexafluorophosphate and 0.5 parts by mass of 3,3'-carbonylbis(7-diethylamino)coumarin dissolved in 100 parts by mass of 2-butanone (hereinafter referred to as , also referred to as "photosensitive material A").

[Light guide plate production process]
In the light guide plate manufacturing process of Example 7, the image display light guide plate 6 is manufactured using two intermediate bodies 1.
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 intermediates.
The sealing layer is made of a transparent material, and is not particularly limited as long as it can bond the intermediate protective layers to each other. In Example 7, the optical adhesive Hardrock (registered trademark) OP-104 was used.
5K (trade name; manufactured by Denka Corporation) is used.
As a result, an intermediate base material with a seal layer step is prepared in which the opening surrounded by the seal layer has a size of 50 mm x 50 mm.
After that, the above-mentioned photosensitive material A is applied as a photopolymer material for hologram on this intermediate base material.
is applied by spin coating. The photosensitive material is applied so that the thickness after drying is 5 μm.
Thereafter, the other intermediate base material is laminated on the seal layer and the photosensitive material so that its protective layer faces the protective layer of the intermediate base material with the seal layer, and press laminated under reduced pressure. The conditions for press bonding are an absolute pressure of 5 kPa, a temperature of 70° C., and a press pressure of 0.04 MPa.
Thereafter, a diffraction grating is recorded on the photosensitive material of the press-bonded laminate. In this step, the temperature of the laminate is maintained at 20°C. In the diffraction grating, interference fringes are formed by irradiating a stacked body with two laser beams and adjusting the irradiation angle and intensity of each laser beam so that a necessary diffraction pattern is formed. As a result, a diffraction grating is recorded on the photosensitive material.
A specific diffraction grating is a diffraction grating that diffracts each light in the red, green, and blue wavelength range that is incident as image light into the incident part, and emits it from the display part at the position corresponding to the pixel of the image light. A color display diffraction grating is formed.
After that, while the laminate was kept at 20°C, ultraviolet light (wavelength 365 nm, irradiance 80 W/
cm ² ) is irradiated over the entire surface of the laminate for 30 seconds from one side. A high-pressure mercury lamp is used as the ultraviolet light source.
Thereby, the sealing layer is cured, and the image display light guide plate 6 of Example 7 is produced.

[Example 8]
Example 8 uses the intermediate body 2 to produce the image display light guide plate 6 of the embodiment.
The image display light guide plate 6 of Example 8 is produced in the same manner as Example 7 except that the intermediate body 2 is used.

[Example 9]
In Example 9, the intermediate body 3 is used to produce the image display light guide plate 6 of the embodiment.
The image display light guide plate 6 of Example 9 is produced in the same manner as Example 7 except that the intermediate body 3 is used.

[Example 10]
Example 10 uses the intermediate body 4 to produce the image display light guide plate 6 of the embodiment. The image display light guide plate 6 of Example 10 was prepared in the same manner as Example 7 except that the intermediate body 4 was used.
is produced.

[Example 11]
Example 11 uses the intermediate body 5 to produce the image display light guide plate 6 of the embodiment. The image display light guide plate 6 of Example 11 was prepared in the same manner as Example 7 except that the intermediate 5 was used.
is produced.

[Example 12]
Example 12 uses the intermediate body 6 to produce the image display light guide plate 6 of the embodiment. The image display light guide plate 6 of Example 12 was prepared in the same manner as Example 7 except that the intermediate body 6 was used.
is created.

[Comparative example 4]
In Comparative Example 4, an image display light guide plate is manufactured using Intermediate 7. An image display light guide plate 6 of Comparative Example 4 is produced in the same manner as Example 7 except that Intermediate 7 is used instead of Intermediate 1.

[Comparative example 5]
In Comparative Example 5, a light guide plate for image display is produced using Intermediate 8. An image display light guide plate of Comparative Example 5 is produced in the same manner as in Example 7 except that intermediate 8 is used.

[Comparative example 6]
In Comparative Example 6, a light guide plate for image display is manufactured using Intermediate 9. An image display light guide plate of Comparative Example 6 is produced in the same manner as in Example 7 except that intermediate 9 is used.

<Evaluation method>
Next, the evaluation method for each manufacturing example will be explained. The evaluation is performed by evaluating the clarity of the displayed image.

[Evaluation of clarity of displayed image]
As samples for measuring the clarity of displayed images, samples that were not subjected to a moist heat test (in Table 2,
Prepare "Initial"). The sharpness of the measurement sample is measured based on the measurement method described above in the embodiment. Each measurement sample is assembled into the above-mentioned display device.
A luminance meter BM-8 (trade name; manufactured by Topcon Co., Ltd.) is used to evaluate the clarity of the displayed image.
A white image and a character display image are used as input images for evaluation.
The evaluation is performed by visually determining how the white image and character display image appear. As the character image, "ABCDE" within 10 mm x 100 mm is displayed.
If the rainbow colors are not visible in the white image and the characters are clearly visible in the character display image,
It is determined that the clarity is good and there is no problem with the displayed image (denoted as "A" in Table 2).
If the characters are clearly visible but rainbow colors are visible in the white image, it is determined that the displayed image is usable but the image quality is poor (denoted as "B" in Table 2).
If a rainbow color appears in the white image and the outline of the character appears blurred in the character display image, the display image is determined to be unusable (denoted as "C" in Table 2).
After conducting the above-mentioned heat and humidity durability test on the measurement sample, the same evaluation of sharpness is performed (described as "after the heat and humidity durability test" in Table 2).

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

<Evaluation results>
As shown in Table 2, the clarity of the displayed images of Examples 7 to 12 was good both at the initial stage and after the wet heat durability test, and it can be determined that there were no problems with the displayed images. On the other hand, the clarity of the images displayed in Comparative Examples 4 to 6 can be determined to be inferior to each of the Examples.

Although preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples. Additions, omissions, substitutions, and other changes to the configuration are possible without departing from the spirit of the present invention.
Moreover, the invention is not limited by the foregoing description, but only by the scope of the appended claims.

The image display light guide plate of the present invention suppresses haze increase even in a humid heat environment and can maintain a clear image, so it is useful for display devices in VR and AR applications, for example.
For example, the image display light guide plate of the present invention is useful for display devices such as head-up displays, wearable displays, and head-mounted displays.

1 First resin base material 22 First protective layer 3 Hologram layer 3a Display surface 3b Waveguide diffraction grating section 3c Display diffraction grating section 24 Second protective layer 5 Second resin base material 6 Image display light guide plate 6a Incidence Section 6d Display section 10 Display device 12 Incident optical system 13 Image light projection section 14 Luminance meter 15 Measuring device 22A First organic material layer 22B First inorganic material layer 24A Second organic material layer 24B Second inorganic material layer

Claims (9)

A guide for image display in which a first resin base material, a first protective layer containing a (meth)acrylic resin containing repeating units derived from polyfunctional (meth)acrylate, and a hologram layer are arranged in this order in the thickness direction. A light guide plate for image display, wherein the first protective layer has a haze increase of 0.1% or less after 500 hours in an environment of 85° C. and 85% RH. The first protective layer is a cured product of a (meth)acrylic resin composition containing a matrix resin component containing a polyfunctional (meth)acrylate and a compound having one or more double bonds in the molecule. The light guide plate for image display according to claim 1, comprising an organic material layer. The light guide plate for image display according to claim 1 or 2, wherein the compound is a leveling agent. The image according to claim 3, wherein the content of the leveling agent in the (meth)acrylic resin composition is 0.01 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the matrix resin component. Light guide plate for display. The light guide plate for image display according to any one of claims 1 to 4, wherein the first protective layer has a thickness of 1 μm or more and 15 μm or less. The image display light guide plate according to claim 1, wherein the first protective layer further includes a first inorganic material layer. The first inorganic material layer includes 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. The image display light guide plate according to any one of items 1 to 6. The light guide plate for image display according to any one of claims 1 to 7, wherein the first inorganic material layer has a thickness of 50 nm or more and 5000 nm or less. The light guide plate for image display according to any one of claims 1 to 8, wherein the hologram layer is made of a single or volume hologram material.

Images