Image display device and method for manufacturing an image display device

Abstract

To provide an image display device and a method for manufacturing an image display device that make the visibility of the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit, and maintain the brightness of the image display area 3 when the display is lit. [Solution] The image display device 1 comprises a cover panel 2, an image panel 4 having an image display area 3 and a non-display area 9, a light-shielding layer 6 provided at a position corresponding to the periphery of the non-display area 9 of the cover panel 2, and an adhesive layer 5 that joins the light-shielding layer 6 side of the cover panel 2 to the image panel 4. The adhesive layer 5 comprises a first adhesive layer 7 provided at a position corresponding to the image display area 3 and exhibiting transmittance to light with a wavelength of 550 nm such that the color of the light-shielding layer 6 and the image panel 4 when the light is off are similar, and a second adhesive layer 8 that is in contact with the light-shielding layer 6 and the first adhesive layer 7, and is provided around the first adhesive layer 7, with a transmittance to light with a wavelength of 550 nm higher than that of the light-shielding layer 6 and a transmittance to light with a wavelength of 550 nm lower than that of the first adhesive layer 7.

Description

[Technical Field]

[0001] This technology relates to an image display device and a method for manufacturing an image display device. [Background technology]

[0002] In recent years, there has been a growing demand for creating a sense of luxury in the interior space of vehicles. For example, in the case of displays (image panels), there is a demand for them to blend seamlessly with the surrounding instrument panel when the display is not lit, i.e., when the display is not in operation.

[0003] Figure 11 is a plan view showing an example of a conventional image display device 100. In the image display device 100, the boundary 104 between the light-shielding layer 102 of the cover panel 101 (top cover) and the image display area 103 of the image panel is easily visible, and a sense of unity has not been achieved. Thus, there is a need to make the visibility of the boundary 104 more seamless when the display is not lit. In addition to making the visibility of the boundary 104 more seamless when the display is not lit, there is also a need to maintain the brightness of the image display area 103 when the display is lit (when the display is operating).

[0004] Patent Document 1 describes a vehicle display device that can display display areas shown on different display units with a good sense of seamlessness, wherein the cover glass is provided along the boundary between the first display area and the second display area, and has a gradient portion that gradually becomes thinner as it moves away from the boundary.

[0005] However, the technology described in Patent Document 1 enables seamless display of multiple display units when the display is lit, but does not make the visibility of the boundary between the light-shielding layer and the image display area seamless when the display is not lit.

[0006] Patent Document 2 describes a vehicle display device that can create a sense of unity between the design plate and the image display surface. This device has a gradient portion provided on the image display surface side of the substrate, between the transparent portion and the light-shielding portion, formed by changing the density per unit area of ​​multiple granular dots made of a light-shielding printing layer of the same color as the light-shielding printing layer, and an overcoat portion that covers the surface of the multiple dots with a transparent printing layer. Patent Document 2 also states that the overcoat portion may be formed of a smoke material or the like.

[0007] However, the technology described in Patent Document 2 uses a light-shielding printed layer for the gradient area, so there are concerns that it may not achieve a seamless effect due to diffuse reflection unless used in combination with a light-reducing (smoke) overcoat resin with low transmittance. In addition, because the overcoat layer for the gradient area and the image display area are integrated, there are concerns about a significant decrease in image brightness when the display is lit. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2024-048141 [Patent Document 2] Japanese Patent Publication No. 2019-086378 [Overview of the project] [Problems that the invention aims to solve]

[0009] This technology was proposed in light of the conventional situation described above, and provides an image display device and a method for manufacturing an image display device that can make the boundary between the light-shielding layer and the image display area seamless when the display is not lit, and maintain the brightness of the image display area when the display is lit. [Means for solving the problem]

[0010] The image display device according to this technology comprises a cover panel, an image panel having an image display area, an adhesive layer joining the cover panel and the image panel, and a light-shielding layer provided on the periphery of the cover panel. The adhesive layer comprises a first adhesive layer provided at a position corresponding to the image display area and exhibiting transmittance to light with a wavelength of 550 nm such that the color of the image panel when the light is turned off is similar to that of the light-shielding layer, and a second adhesive layer in contact with the light-shielding layer and the first adhesive layer, and provided around the first adhesive layer, having a higher transmittance to light with a wavelength of 550 nm than the light-shielding layer and a lower transmittance to light with a wavelength of 550 nm than the first adhesive layer.

[0011] A method for manufacturing an image display device according to this technology comprises the steps of: A step of forming a second adhesive layer by applying a composition for a second adhesive layer to the periphery of the non-display area of ​​an image panel having an image display area and a non-display area, or to the periphery of a light-shielding layer provided at a position corresponding to the periphery of the non-display area of ​​a cover panel, and curing it; B step of forming a first adhesive layer by applying a composition for a first adhesive layer to the inner periphery of the second adhesive layer, and curing it; and C step of bonding the light-shielding layer side of the cover panel to the image panel, wherein the first adhesive layer is provided at a position corresponding to the image display area and exhibits a transmittance to light with a wavelength of 550 nm such that the color of the light-shielding layer and the image panel when the lights are off are similar; the second adhesive layer is in contact with the light-shielding layer and the first adhesive layer and is provided around the first adhesive layer, with a transmittance to light with a wavelength of 550 nm higher than that of the light-shielding layer and a transmittance to light with a wavelength of 550 nm lower than that of the first adhesive layer. [Effects of the Invention]

[0012] This technology seamlessly improves the visibility of the boundary between the light-shielding layer and the image display area when the display is not lit, while maintaining the brightness of the image display area when the display is lit. [Brief explanation of the drawing]

[0013] [Figure 1]FIG. 1 is a plan view showing an example of an image display device according to the present technology. [Figure 2] FIG. 2 is a cross-sectional view showing an example of the a-a' cross-section in FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view showing an example of an image display device according to the present technology. [Figure 4] FIG. 4 is a cross-sectional view showing an example of an image display device according to the present technology. [Figure 5] FIG. 5 is a cross-sectional view showing an example of an image display device according to the present technology. [Figure 6] FIG. 6 is a cross-sectional view showing an example of an image display device according to the present technology. [Figure 7] FIG. 7 is a cross-sectional view showing an example of an image display device according to the present technology. [Figure 8] FIG. 8 is a perspective view showing an example of a vehicle instrument panel to which an image display device according to the present technology is applied. [Figure 9] FIG. 9 is a cross-sectional view showing an example of a vehicle instrument panel to which an image display device according to the present technology is applied. [Figure 10] FIG. 10 is a perspective view for explaining an example of a manufacturing method of an image display device according to the present technology. [Figure 11] FIG. 11 is a plan view showing an example of a conventional image display device.

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] <Image display device> Figure 1 is a plan view showing an example of an image display device according to this technology. Figure 2 is a cross-sectional view showing an example of the a-a' section in Figure 1. The image display device 1 comprises a cover panel 2, an image panel 4 having an image display area 3 and a non-display area 9, an adhesive layer 5 joining the light-shielding layer 6 side of the cover panel 2, and a light-shielding layer 6 provided at a position corresponding to the periphery of the non-display area 9 of the cover panel 2. The adhesive layer 5 comprises a first adhesive layer 7 and a second adhesive layer 8. The first adhesive layer 7 and the second adhesive layer 8 have different transmittances to light with a wavelength of 550 nm. The first adhesive layer 7 is provided at a position corresponding to the image display area 3 and exhibits a transmittance to light with a wavelength of 550 nm such that the color of the light-shielding layer 6 and the image panel 4 when the light is off are similar. The second adhesive layer 8 is provided in a position corresponding to the non-display area 9, is in contact with the light-shielding layer 6 and the first adhesive layer 7, and is provided around the first adhesive layer 7, with a transmittance to light with a wavelength of 550 nm higher than that of the light-shielding layer 6 and a transmittance to light with a wavelength of 550 nm lower than that of the first adhesive layer 7.

[0015] In the image display device 1, a second adhesive layer 8 is formed between the light-shielding layer 6 and the first adhesive layer 7. In addition to the second adhesive layer 8 being formed between the light-shielding layer 6 and the first adhesive layer 7, the first adhesive layer 7, which exhibits transmittance to light with a wavelength of 550 nm such that the color of the light-shielding layer 6 and the image panel 4 when the light is off are similar, is provided at a position corresponding to the image display area 3. Therefore, compared to, for example, the case where the light-shielding layer 6 and the transparent adhesive layer are adjacent, the image display device 1 has a more stepped gradient formed from the light-shielding layer 6 to the first adhesive layer 7. As a result, for example, when the display of the image display device 1 is not lit, if a user views the image display device 1 from the viewing direction D in Figure 2, the boundary 10 between the light-shielding layer 6 and the image display area 3 becomes less visible. In such an image display device 1, the second adhesive layer 8 makes the visibility of the boundary between the light-shielding layer 6 and the image display area 3 in the viewing direction D when the display is not lit more seamless. Here, whether the visibility of the boundary between the light-shielding layer 6 and the image display area 3 is seamless when the display is not lit can be evaluated by the method described in the embodiment below.

[0016] To determine whether the visibility of the boundary between the light-shielding layer 6 and the image display area 3 is seamless when the display is not lit, for example, the color difference △E of the second adhesive layer 8 relative to the light-shielding layer 6 can be used as a reference. For example, if the color difference △E is less than 1.9, the visibility of the boundary between the light-shielding layer 6 and the image display area 3 tends to be seamless when the display is not lit. The color difference △E can be measured by the method described in the examples below.

[0017] Furthermore, since the first adhesive layer 7 is provided in the image display device 1 at a position corresponding to the image display area 3 in the viewing direction D in Figure 2, the brightness of the image display area 3 can be maintained when the display is lit. Therefore, the image display device 1 does not require measures to improve brightness by increasing the current of, for example, the backlight or OLED (Organic Light Emitting Diode), and can suppress the reduction in the lifespan of the backlight or OLED and the increase in power consumption.

[0018] In this way, the image display device 1 makes the visibility of the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit, and maintains the brightness of the image display area 3 when the display is lit.

[0019] [Cover Panel] The cover panel 2 is light-transmitting and is laminated with the image panel 4 via an adhesive layer 5 to cover and protect the display surface of the image panel 4 while ensuring the visibility of the image panel 4.

[0020] The material for the cover panel 2 only needs to have light transmittance that allows the image formed on the image panel 4 to be visible. Examples include glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate. These materials can be treated with a single-sided or double-sided hard coat, anti-reflective coating, etc. Furthermore, if the image panel 4 is a touch panel, for example, a part of the touch panel components can be used as the cover panel 2.

[0021] Furthermore, to improve the brightness and contrast of the displayed image, the cover panel 2 has a black frame-shaped light-shielding layer 6, known as a black matrix, formed in the area corresponding to the periphery of the non-display area 9 of the image panel 4. The light-shielding layer 6 is formed to a uniform thickness by, for example, applying a colored paint such as black using a screen printing method, and then drying and curing it. The thickness of the light-shielding layer 6 can be, for example, 5 to 100 μm. Preferably, the light-shielding layer 6 has a transmittance of 0% for light with a wavelength of 550 nm.

[0022] The shape of the cover panel 2 is not particularly limited and can be set appropriately according to the shape of the image display device 1, etc. For example, the cover panel 2 is a rectangular plate. The cover panel 2 may also have a curved shape, for example, a concave curved shape in one direction, a convex curved shape, a paraboloid of revolution, a hyperbolic paraboloid, or other quadratic curved shape, and may also have flat parts in part of the curved shape and the quadratic curved shape. The dimensional characteristics such as the shape and thickness of the cover panel 2, and physical properties such as elasticity can be appropriately determined according to the intended use of the image display device 1.

[0023] [Image Panel] The image panel 4 has an image display area 3 and a non-display area 9. Examples of image display elements for the image panel 4 include liquid crystal display panels, organic EL display panels, plasma display panels, and touch panels. Here, a touch panel refers to an image display / input panel that combines a display element such as a liquid crystal display panel with a position input device such as a touchpad. The surface shape of the cover panel 2 side of the image panel 4 is not particularly limited, but is preferably flat, for example. A polarizing plate may also be placed on the surface of the image panel 4. The non-display area 9 is an area where no image is displayed. The width of each non-display area 9 depends on the type of image panel 4, but can be, for example, about 1 to 3 mm.

[0024] [Adhesive layer] The adhesive layer 5 joins the cover panel 2 and the image panel 4. The adhesive layer 5 is interposed between the cover panel 2 and the image panel 4. The adhesive layer 5 comprises a first adhesive layer 7 and a second adhesive layer 8.

[0025] [First adhesive layer] The first adhesive layer 7 is light-transmitting and is provided at a position corresponding to the image display area 3, making the image displayed by the image panel 4 visible. In order to more effectively maintain the brightness of the image display area 3 when the display is lit, and to make the visibility of the boundary between the light-shielding layer 6 and the image display area 3 seamless when the display is not lit, the first adhesive layer 7 preferably has a transmittance of 50 to 80% for light with a wavelength of 550 nm, and may be 55 to 80%, or 60 to 80%. Depending on the brightness characteristics of the image panel 4 and the required brightness range, the transmittance of the first adhesive layer 7 for light with a wavelength of 550 nm may be less than 60%, or less than 50%.

[0026] The thickness of the first adhesive layer 7 is not particularly limited as long as it is within the range in which the effects of this technology are achieved, and can be set appropriately depending on the application. For example, it can be 100 to 500 μm, or it may be 50 to 500 μm.

[0027] The first adhesive layer 7 is formed by curing a composition 11 for the first adhesive layer, such as a photocurable composition (photocurable resin composition). The composition 11 for the first adhesive layer is preferably liquid at 25°C. Furthermore, in order to more effectively achieve good inkjet suitability under normal inkjet ejection conditions, the viscosity of the composition 11 for the first adhesive layer at 25°C is preferably 1 mPa·s or more, may be 10 mPa·s or more, may be 1 to 30 mPa·s, or may be 3 to 20 mPa·s.

[0028] The composition 11 for the first adhesive layer may contain, for example, the following components (A), (B), (C), and (D), or components (B), (C), and (D). The composition 11 for the first adhesive layer contains a coloring agent, such as a black pigment.

[0029] Component (A) is a film-forming component of the first adhesive layer 7 which has light transmittance, and can be an acrylic oligomer or an acrylic polymer. Examples of acrylic oligomers include (meth)acrylate oligomers having polyisoprene, polyurethane, polybutadiene, etc. as a backbone. In this specification, "(meth)acrylate" is a term that encompasses both acrylate and methacrylate. Examples of (meth)acrylate oligomers with a polyisoprene backbone include esterified products of a maleic anhydride adduct of a polyisoprene polymer and 2-hydroxyethyl methacrylate (UC102 (polystyrene equivalent molecular weight 17,000), UC203 (polystyrene equivalent molecular weight 35,000), UC-1 (molecular weight approximately 25,000), all manufactured by Kuraray Co., Ltd.). Examples of (meth)acrylic oligomers having a polyurethane skeleton include aliphatic urethane acrylates (EBECRYL230 (molecular weight 5,000), manufactured by Daicel Ornex, UA-1, manufactured by Light Chemical Co., Ltd.). Examples of acrylic polymers include (meth)acrylate polymers that do not have (meth)acroyl groups. For example, examples include (meth)acrylate polymers that do not have (meth)acroyl groups and have a hydroxyl value of 120 mgKOH / g or more, more preferably 170 mgKOH / g or more. By using such base components, for example, it is possible to impart plasticity to the cured product while ensuring good film formation (film maintenance) and adhesion.

[0030] The hydroxyl value of the (meth)acrylate polymer is the mass (mg) of KOH required to neutralize the acetic acid produced by hydrolyzing the acetyl groups after acetylating the hydroxyl groups in 1g of polymer. Therefore, a higher hydroxyl value means a greater number of hydroxyl groups. By setting the hydroxyl value of the (meth)acrylate polymer of component (A) to, for example, 120 mg KOH / g or higher, it is possible to suppress a decrease in the crosslinking density of the cured product of the photocurable resin composition, and in particular, to suppress a decrease in the elastic modulus at high temperatures. Furthermore, from the viewpoint of preventing the crosslinking density of the cured product of composition 11 for the first adhesive layer from becoming too high and losing flexibility, the hydroxyl value of the (meth)acrylate polymer is preferably 400 mg KOH / g or less, and more preferably 350 mg KOH / g or less. Furthermore, by using a (meth)acrylate polymer in component (A) that does not have a (meth)acroyl group, it is possible to prevent it from being excessively incorporated into the main chain of the polymerization chain composed of (meth)acrylate monomers of components (B) and (C).

[0031] When component (A) contains a (meth)acrylate polymer, if the weight-average molecular weight Mn of the (meth)acrylate polymer is too small, the number of molecules without hydroxyl groups increases, which tends to increase the risk of bleeding, etc. Therefore, it is preferably 5,000 or more, more preferably 100,000 or more. Also, if the weight-average molecular weight Mn of the (meth)acrylate polymer in component (A) is too large, it tends to lead to poor dispensing due to increased viscosity, so it is preferably 500,000 or less, more preferably 300,000 or less. In this specification, the weight-average molecular weight Mw and number-average molecular weight Mn of the polymer can be measured by gel permeation chromatography (GPC) (converted to standard polystyrene molecular weight).

[0032] Furthermore, if the dispersion (Mw / Mn) of the (meth)acrylate polymer of component (A) is too low, the polymer and unreacted monomers tend to separate easily, so it is preferably 3 or higher. If it is too high, it will result in the inclusion of undesirable, relatively low molecular weight polymer components, so it is preferably 10 or lower.

[0033] As such a component (A), a copolymer of a hydroxyl group-containing (meth)acrylate monomer and a hydroxyl group-free (meth)acrylate monomer is a preferred example. Component (A) is preferably liquid at room temperature.

[0034] The hydroxyl group-containing (meth)acrylate monomers that constitute the (meth)acrylate polymer of component (A) are (meth)acrylates having one or more hydroxyl groups in the molecule. Specifically, examples include 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-chloropropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, ethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate, propylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, cyclohexyl dimethanol mono(meth)acrylate, etc. Among these, 2-hydroxyethyl (meth)acrylate is a preferred example in terms of polarity control and cost.

[0035] Examples of hydroxyl group-free (meth)acrylate monomers that can constitute the (meth)acrylate polymer of component (A) include, for example, monocyclic alkyl (meth)acrylates having a linear or branched alkyl group with 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tridecyl (meth)acrylate, and the like.

[0036] A particularly preferred example of the (meth)acrylate polymer of component (A) is a copolymer of 2-hydroxyethyl acrylate and 2-ethylhexyl acrylate, from the viewpoint of availability and feasibility of realizing the effects of the invention. Isobornyl acrylate may be further copolymerized.

[0037] If the composition 11 for the first adhesive layer contains component (A), the amount of component (A) in the composition 11 for the first adhesive layer can be changed according to the amounts of the other components (B), (C), and (D). For example, the composition 11 for the first adhesive layer does not have to contain component (A). Also, if the composition 11 for the first adhesive layer contains component (A), the amount of component (A) in the composition 11 for the first adhesive layer can be, for example, 1% by mass or more, or 10% by mass or more. Also, the amount of component (A) in the composition 11 for the first adhesive layer can be 55% by mass or less, or 45% by mass or less.

[0038] The composition 11 for the first adhesive layer preferably contains a hydroxyl group-containing monotubular (meth)acrylate monomer as component (B) as a polymerization component. This is because, when component (A) contains a hydroxyl group-containing (meth)acrylate polymer, the affinity with the hydroxyl group-containing (meth)acrylate polymer is high, and reliability in high temperature and high humidity environments is further improved. In this case, there may be multiple hydroxyl groups in the monomer molecule, but it is preferable that there is one in the monomer molecule.

[0039] Specific examples of the hydroxyl group-containing monofunctional (meth)acrylate monomer of component (B) include monomers similar to the hydroxyl group-containing (meth)acrylate monomer of component (A) that can constitute the (meth)acrylate polymer. Among these, at least one selected from 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate is preferred.

[0040] In the composition 11 for the first adhesive layer, the content of component (B), the hydroxyl group-containing monotubular (meth)acrylate monomer, is preferably 1% by mass or more, more preferably 5% by mass or more, because if it is too low, it tends to become unreliable in high temperature and high humidity environments. If it is too high, the balance of polarity of the resin before or after curing is disrupted, and it tends to become opaque, so it is preferably 30% by mass or less, more preferably 25% by mass or less.

[0041] The composition 11 for the first adhesive layer preferably contains a hydroxyl group-free monotubular (meth)acrylate monomer as component (C), which is a polymerization component. The reason why a hydroxyl group-free monomer is preferred is to set the adhesion and viscosity of the cured product of the composition 11 for the first adhesive layer (first adhesive layer 7) to a better range, and to further improve the performance of the first adhesive layer 7.

[0042] Specific examples of the hydroxyl group-free monofunctional (meth)acrylate monomer of component (C) include monomers similar to the hydroxyl group-free (meth)acrylate monomer of component (A) that can constitute the (meth)acrylate polymer. For example, at least one selected from isobornyl acrylate, isostearyl (meth)acrylate, phenoxypolyethylene glycol acrylate, and ethyl carbitol (meth)acrylate is preferred, and combinations thereof may also be used.

[0043] In the composition 11 for the first adhesive layer, if the amount of component (C) is too small, it tends to become highly viscous, so it is preferably 30% by mass or more, more preferably 65% ​​by mass or more, and if it is too large, it tends to become brittle, so it is preferably 90% by mass or less, more preferably 75% by mass or less.

[0044] The composition 11 for the first adhesive layer may use known photoradical polymerization initiators as component (D). In particular, component (D) preferably contains a hydrogen abstraction type photopolymerization initiator, and a hydrogen abstraction type photopolymerization initiator may be used in combination with other photopolymerization initiators (e.g., intramolecular cleavage type photopolymerization initiators).

[0045] As hydrogen abstraction type photopolymerization initiators, known hydrogen abstraction type photopolymerization initiators can be used, such as diaryl ketones like benphenone and phenylglyoxylates like methylbenzoyl formate. A preferred example is methylbenzoyl formate, which does not yellow and has high hydrogen abstraction ability.

[0046] In the composition 11 for the first adhesive layer, the content of component (D) is preferably 0.1% by mass or more, more preferably 1% by mass or more, because if it is too little, it tends to result in insufficient crosslinking, and if it is too much, it tends to cause deterioration of environmental reliability, so it is preferably 10% by mass or less, more preferably 5% by mass or less.

[0047] The composition 11 for the first adhesive layer may further contain a polyfunctional (meth)acrylate monomer as component (E) to improve the reaction rate and maintain the high-temperature modulus. Specific examples of polyfunctional (meth)acrylate monomers include two or more functional (meth)acrylates such as 1,6-hexanediol diacrylate (HDDA), 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, pentaerythritol triacrylate, and alkoxylated trimethylolpropane acrylate. These can have other functional groups such as hydroxyl groups, as long as they do not impair the effects of this technology. Among these, a preferred specific example of a polyfunctional (meth)acrylate monomer is alkoxylated trimethylolpropane acrylate (e.g., ethoxylated trimethylolpropane triacrylate). When the composition 11 for the first adhesive layer contains component (E), the content of component (E) in the composition 11 for the first adhesive layer is preferably 0.05% or more, more preferably 0.1% or more, because if it is too little, it tends to result in a low crosslinking density, and preferably 5% by mass or less, more preferably 3% by mass or less, because if it is too much, it tends to become brittle.

[0048] The composition 11 for the first adhesive layer may contain various additives in addition to the components (A) to (D) described above, as long as they do not impair the effects of this technology. For example, polybutadiene-based plasticizers, polyisoprene-based plasticizers, phthalate ester-based plasticizers, adipic acid ester-based plasticizers, polyisoprene-based plasticizers, polyether-based plasticizers, etc. can be used as plasticizers (liquid plasticizers) to reduce curing shrinkage. Also, terpene resins, rosin resins, petroleum resins, etc. can be used as tackifiers to improve tackiness. Furthermore, 2-mercaptoethanol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-ethylhexyl thioglycolate, 2,3-dimethylcapto-1-propanol, α-methylstyrene dimer, etc. may be used as chain transfer agents to adjust the molecular weight of the cured product. Furthermore, if necessary, general additives such as adhesion improvers like silane coupling agents, antioxidants, leveling agents (surface modifiers), and UV absorbers may be used.

[0049] The content of each component in the composition 11 for the first adhesive layer can be, for example, 1 to 55% by mass of component (A), 1 to 30% by mass of component (B), 30 to 90% by mass of component (C), 0.1 to 10% by mass of component (D), and a coloring agent (e.g., black pigment) that is greater than 0% by mass and 0.8% by mass or less, or 0.1 to 1.2% by mass. Alternatively, the content of each component in the composition 11 for the first adhesive layer can be, for example, 10 to 25% by mass of component (B), 65 to 75% by mass of component (C), 1 to 5% by mass of component (D), 0.05 to 3% by mass of component (E), a coloring agent (e.g., black pigment) that is 0.1 to 1.2% by mass (or greater than 0% by mass and 0.8% by mass or less), and other components that are 5% by mass or less.

[0050] [Second adhesive layer] The second adhesive layer 8 is provided in a position corresponding to the non-display area 9. The second adhesive layer 8 is in contact with the light-shielding layer 6 and the first adhesive layer 7, and is provided around the first adhesive layer 7. As shown in Figure 2, for example, the second adhesive layer 8 covers a portion of the surface of the light-shielding layer 6 on the image panel 4 side in the non-display area 9, and is formed between the image panel 4 and the cover panel 2 in the non-display area 9. It is preferable that the second adhesive layer 8 is formed in an area other than the image display area 3. The width of the second adhesive layer 8 that can be seen when viewing the image display device 1 from the viewing direction D in Figure 2, specifically the width of the boundary 10 and the boundary 12 between the second adhesive layer 8 and the first adhesive layer 7, is preferably not too large from the viewpoint of not affecting the brightness of the image display area 3 when the display is lit, and preferably not too small from the viewpoint of making the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit. For example, the width between boundary 10 and boundary 12 can be approximately 1 to 3 mm.

[0051] With respect to making the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit, the second adhesive layer 8 is not particularly limited as long as its transmittance to light at a wavelength of 550 nm is higher than that of the light-shielding layer 6 and lower than that of the first adhesive layer 7. For example, the second adhesive layer 8 preferably has a transmittance of 70% or less to light at a wavelength of 550 nm, but may also be 60% or less, 56% or less, 50% or less, 34% or less, 20% or less, 15-70%, 15-60%, 15-56%, 20-60%, 20-50%, or 15-20%. For example, by having a transmittance of 70% or less to light at a wavelength of 550 nm, the visibility of the boundary between the light-shielding layer 6 and the image display area 3 when the display is not lit can be made more seamless. Furthermore, the second adhesive layer 8 is not particularly limited in terms of the lower limit of its transmittance to light at a wavelength of 550 nm. For example, it may be 1% or more, 5% or more, or 10% or more, but a transmittance of 15% or more tends to result in better photocurability of the composition 13 for the second adhesive layer 8.

[0052] The second adhesive layer 8 is, for example, a cured version of composition 13 for the second adhesive layer. Composition 13 for the second adhesive layer is, for example, a photocurable composition (photocurable resin composition). Composition 13 for the second adhesive layer has a higher content of a coloring agent, such as black pigment, than the composition 11 for the first adhesive layer described above. Composition 13 for the second adhesive layer can have the same configuration as composition 11 for the first adhesive layer, except that the content of the coloring agent is different. In composition 13 for the second adhesive layer, the content of black pigment, which is an example of a coloring agent, can be, for example, 0.10 to 2.0% by mass, may be 0.19% by mass or more, may be 0.19% by mass or more and less than 0.85% by mass, or may be 0.19 to 0.80% by mass.

[0053] The optimal transmittance of the second adhesive layer 8 for light with a wavelength of 550 nm depends on the color of the light-shielding layer 6 and the color of the image display area 3 when the display is not lit. Since the color of the light-shielding layer 6 and the color of the image display area 3 when the display is not lit vary depending on the materials used and the design, it is preferable that the optimal transmittance of the second adhesive layer 8 for light with a wavelength of 550 nm can be easily adjusted. The transmittance of the second adhesive layer 8 for light with a wavelength of 550 nm can be set to a desired value by adjusting, for example, the transmittance characteristics of the composition 13 for the second adhesive layer (e.g., the amount of colorant) or the thickness of the second adhesive layer 8.

[0054] Figure 3 is a cross-sectional view showing an example of an image display device 20 according to this technology. The image display device 20 has the same configuration as the image display device 1, except that the thickness of the second adhesive layer 8 in the non-display area 9 (length of the second adhesive layer 8 in the viewing direction D) is smaller than that of the image display device 1, and the width of the first adhesive layer 7 on the image panel 4 side extends to a position corresponding to the non-display area 9. In this way, the image display device 20 has the second adhesive layer 8 and the first adhesive layer 7 stacked at a position corresponding to the non-display area 9. As in the image display device 20, the transmittance of the second adhesive layer 8 to light with a wavelength of 550 nm can be adjusted by changing the thickness of the second adhesive layer 8.

[0055] The image display device 1 may be formed such that the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 decreases from the light-shielding layer 6 side toward the first adhesive layer 7 side. For example, the image display device 1 may be formed such that the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 decreases continuously or stepwise from the light-shielding layer 6 side toward the first adhesive layer 7 side.

[0056] Figure 4 is a cross-sectional view showing an example of an image display device 30 according to this technology. The image display device 30 has the same configuration as the image display device 1, except that the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 is formed to continuously decrease from the light-shielding layer 6 side toward the first adhesive layer 7 side (image display area 3 side), starting from the boundary 10. By continuously changing the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9, as in the image display device 30, the transmittance of the adhesive layer 5 for 550 nm light on the light-shielding layer 6 side can be made smaller than the transmittance of the first adhesive layer 7 side for 550 nm light, and a more gradual gradient is formed from the light-shielding layer 6 to the first adhesive layer 7, making the visibility of the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit. Furthermore, the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 may be formed to continuously decrease from the light-shielding layer 6 side toward the first adhesive layer 7 side, starting from, for example, the space between boundary 10 and boundary 12 in the image display device 1 (for example, the central part between boundary 10 and boundary 12). Alternatively, the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 may be formed by a combination of continuously decreasing and gradually decreasing from the light-shielding layer 6 side toward the first adhesive layer 7 side.

[0057] In the image display device 30, for example, the light-shielding layer 6 and the first adhesive layer 7 are in contact on the cover panel 2 side. In the image display device 30, the width of the first adhesive layer 7 is greater on the cover panel 2 side than on the image panel 4 side. In the image display device 30, the width of the second adhesive layer 8 is smaller on the cover panel 2 side than on the image panel 4 side.

[0058] The image display device 1 may be formed such that the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 decreases in stages from the light-shielding layer 6 side toward the first adhesive layer 7 side. Figure 5 is a cross-sectional view showing an example of an image display device 40 according to the present technology. Figure 6 is a cross-sectional view showing an example of an image display device 40A according to the present technology. The image display devices 40 and 40A have the same configuration as the image display device 1, except that the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 decreases in stages from the light-shielding layer 6 side toward the first adhesive layer 7 side. As in the image display devices 40 and 40A, by gradually changing the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9, the transmittance of the adhesive layer 5 to 550nm light on the light-shielding layer 6 side can be made smaller than the transmittance of the first adhesive layer 7 side to 550nm light. Furthermore, a more gradual gradient is formed from the light-shielding layer 6 to the first adhesive layer 7, making the visibility of the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit.

[0059] Figure 7 is a cross-sectional view showing an example of an image display device 50 according to the present technology. Similar to the image display device 30, the image display device 50 has the same configuration as the image display device 1, except that the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9 decreases continuously from the light-shielding layer 6 side to the first adhesive layer 7 side, and the first adhesive layer 7 comprises a first layer 7A with a transmittance of 70% or more for light with a wavelength of 550 nm, and a second layer 7B with a transmittance higher than that of the light-shielding layer 6 for light with a wavelength of 550 nm and lower than that of the first layer 7A for light with a wavelength of 550 nm. In the image display device 50, by continuously changing the thickness of the second adhesive layer 8 at the position corresponding to the non-display area 9, the visibility of the boundary between the light-shielding layer 6 and the image display area 3 when the display is not lit can be made more seamless, similar to the image display device 30.

[0060] The first layer 7A is, for example, a transparent adhesive layer, and its transmittance to light with a wavelength of 550 nm is preferably 70% or more, may be 80% or more, may be greater than 80%, may be 81% or more, may be 85% or more, may be 90% or more, may be 95% or more, may be 98% or more, may be 99% or more, or may be 100%. The thickness of the first layer 7A can be, for example, 50 to 300 μm. The second layer 7B may have a lower transmittance to light with a wavelength of 550 nm than the first adhesive layer 7. The thickness of the second layer 7B can be, for example, 50 to 300 μm. The second layer 7B may be in contact with the cover panel 2 or may be formed in the middle of the first adhesive layer 7.

[0061] Figure 8 is a perspective view showing an example of a vehicle instrument panel 41 to which the image display device (image display devices 1, 20, 30, 40, 40A, 50) according to this embodiment is applied. Figure 9 is a cross-sectional view showing an example of a vehicle instrument panel 41 to which the image display device according to this technology is applied.

[0062] The image display device according to this embodiment can make the visibility of the boundary between the light-shielding layer 6 and the image display area 3 more seamless when the display is not lit, and can therefore be suitably used, for example, as a vehicle instrument panel 41 incorporated within a black housing 42. Furthermore, by using the image display device according to this embodiment as a vehicle instrument panel 41, the design of the interior space can be improved in various vehicle types, including next-generation vehicles equipped with high-definition and curved-surface compatible OLEDs. In addition, since the image display device according to this embodiment can maintain the brightness of the image display area 3 when the display is lit, it can be suitably used, for example, as a vehicle instrument panel 41 in an electric vehicle where power consumption is important.

[0063] <Manufacturing method for image display devices> Figure 10 is a perspective view illustrating an example of a method for manufacturing an image display device according to this technology. The method for manufacturing an image display device according to this embodiment includes, for example, the following steps A, B, and C.

[0064] Step A: The composition 13 for the second adhesive layer is applied to the peripheral edge of the light-shielding layer 6 located at a position corresponding to the peripheral edge of the non-display area 9 of the cover panel 2, or to the peripheral edge of the non-display area 9 of the image panel 4, and cured to form the second adhesive layer 8. Step B: The composition 11 for the first adhesive layer is applied to the inner circumference of the second adhesive layer 8 and cured to form the first adhesive layer 7. Step C: The light-shielding layer 6 side of the cover panel 2 is bonded to the image panel 4.

[0065] [Process A] In the manufacturing method of the image display device 1, for example, in step A (ST1 in Figure 10), it is preferable to apply the composition 13 for the second adhesive layer to the surface of the cover panel 2 on the side where the light-shielding layer 6 is formed using an inkjet device 43 to form a composition film 44 for the second adhesive layer.

[0066] The inkjet device 43 is an ejection device that employs a so-called inkjet method, having, for example, one or more ejection heads with multiple ejection holes arranged in a predetermined pattern, and ejecting fine droplets from the ejection holes to adhere to the cover panel 2. Compared to, for example, a die coater or dispenser, the inkjet device 43 can coat the material with higher precision in position and size. Furthermore, the inkjet device 43 makes it easy to coat the composition 13 for the second adhesive layer with a desired thickness and pattern, and also offers a fast coating speed.

[0067] The coating thickness of the composition film 44 for the second adhesive layer can be appropriately set according to the surface condition of the cover panel 2 and the image panel 4, the required film properties of the adhesive layer 5, etc. The inkjet device 43 has an ejection head with multiple ejection holes that is installed facing the surface of the cover panel 2, and ejects the composition 13 for the second adhesive layer while moving relative to the cover panel 2. The inkjet device 43 may adjust the ejection width and ejection force by providing multiple ejection heads. Multiple ejection heads may be arranged in parallel or in a staggered pattern. It is preferable that the composition 13 for the second adhesive layer has a low viscosity that can be ejected by the inkjet device 43.

[0068] If the composition 13 for the second adhesive layer is a photocurable composition, it can be cured by light irradiation. The light irradiation conditions for the composition 13 for the second adhesive layer are preferably set to a degree of curing that at least maintains the coated shape of the composition 13 for the second adhesive layer. The light source 45 can be a known light source such as an LED, UV lamp, mercury lamp, metal halide lamp, or xenon lamp.

[0069] Here, the curing rate is defined as the ratio (consumption ratio) of the amount of (meth)acryloyl groups present after light irradiation to the amount of (meth)acryloyl groups present in the composition 13 for the second adhesive layer before light irradiation. A higher curing rate indicates that curing has progressed further. Specifically, the curing rate is measured from 1640 to 1620 cm from the baseline in the FT-IR measurement chart of the composition 13 for the second adhesive layer before light irradiation. -1 The absorption peak height (X) and the FT-IR measurement chart of composition 13 for the second adhesive layer after light irradiation, from baseline 1640 to 1620 cm². -1 The absorption peak height (Y) can be calculated by substituting it into the following equation A. Formula A: Curing rate (%)=[(XY) / X]×100

[0070] The conditions for light irradiation in step A are not particularly limited in terms of the type of light source, output, illuminance, integrated light amount, etc. For example, the curing rate may be limited to a degree that maintains the coated shape of the composition 13 for the second adhesive layer (so-called partial curing), or it may be completely cured (so-called full curing). Partial curing means, for example, that the curing rate of the composition 13 for the second adhesive layer after light irradiation is about 40-50%. Full curing means, for example, that the curing rate of the composition 13 for the second adhesive layer after light irradiation is 90% or more, may be 95% or more, or may be 99% or less.

[0071] In step A, if the desired thickness cannot be obtained with a single application by the inkjet device 43, the composition 13 for the second adhesive layer may be applied multiple times. In this case, after applying the composition 13 for the second adhesive layer multiple times, the composition 13 for the second adhesive layer may be irradiated with light.

[0072] Furthermore, in step A, the process of applying the composition 13 for the second adhesive layer and then irradiating it with light may be repeated multiple times. This makes it possible to sufficiently cure the second adhesive layer even when using a composition 13 for the second adhesive layer with low light transmittance, and for example, a second adhesive layer 8 with low transmittance to light at a wavelength of 550 nm (for example, a second adhesive layer 8 with a transmittance of less than 15% to light at a wavelength of 550 nm) can be obtained.

[0073] [Process B] In step B (ST2 in Figure 10), it is preferable to apply the composition 11 for the first adhesive layer to the inner circumference of the second adhesive layer 8, and then flatten and cure the surface of the composition 11 to form the first adhesive layer 7. In step B, it is preferable to apply the composition 11 for the first adhesive layer using an inkjet device 43 to form the composition film 46 for the first adhesive layer. If the composition 11 for the first adhesive layer is a photocurable composition, it can be cured by light irradiation. The curing method for the composition 11 for the first adhesive layer can be the same as that for the composition 13 for the second adhesive layer in step A. In step B, the process of applying the composition 11 for the first adhesive layer and then irradiating it with light may be repeated multiple times.

[0074] [Process C] In step C, the light-shielding layer side 6 of the cover panel 2 is bonded to the image panel 4. This yields the image display device 1 described above. The bonding of the cover panel 2 and the image panel 4 can be performed by applying pressure under a predetermined temperature environment (e.g., 10 to 80°C) using a known bonding device. To prevent air bubbles from forming between the cover panel 2 and the adhesive layer 5 (first adhesive layer 7 and second adhesive layer 8), the bonding may be performed using a vacuum bonding method.

[0075] In the manufacturing method of the image display device 1, after step C, light irradiation may be further performed from the adhesive layer 5 side of the cover panel 2 to fully cure the composition 13 for the second adhesive layer and the composition 11 for the first adhesive layer.

[0076] From the viewpoint of more effectively achieving the effects of this technology, it is preferable that the manufacturing method of the image display device 1 involves, in step A, applying a photocurable second adhesive layer composition 13 using an inkjet device 43 and curing the photocurable second adhesive layer composition 13 by light irradiation, and in step B, applying a photocurable first adhesive layer composition 11 using an inkjet device 43 and curing the photocurable first adhesive layer composition 11 by light irradiation.

[0077] The method for manufacturing the image display device 1 described above assumes that the composition 13 for the second adhesive layer and the composition 11 for the first adhesive layer are applied to the surface of the cover panel 2, but the method is not limited to this example. For example, the composition 13 for the second adhesive layer and the composition 11 for the first adhesive layer may be applied to the surface of the image panel 4 (for example, the peripheral area of ​​the non-display region 9) before the cover panel 2 is bonded to it.

[0078] In the manufacturing method of the image display device 20 shown in Figure 3, in step A, the second adhesive layer 8 is formed such that its thickness is smaller than that of the image display device 1. In step B, the composition 11 for the first adhesive layer is applied to the inner circumference of the second adhesive layer 8, and then the composition 11 for the first adhesive layer is applied so that the width of the outermost first adhesive layer 7 extends to the non-display area 9. The surface of the composition 11 for the first adhesive layer is then flattened and cured to form the first adhesive layer 7.

[0079] In the manufacturing method of the image display device 30 shown in Figure 4, for example, in step A, the composition 13 for the second adhesive layer is applied to the peripheral edge of the non-display area 9 of the image panel 4, and the second adhesive layer 8 is formed such that the thickness of the second adhesive layer 8 in the non-display area 9 decreases continuously toward the image display area 3 side. In step B, the composition 11 for the first adhesive layer is applied to the inner periphery of the second adhesive layer 8, and then the surface of the composition 11 for the first adhesive layer is flattened and cured to form the first adhesive layer 7.

[0080] In the manufacturing method of the image display devices 40 and 40A shown in Figures 5 and 6, for example, in step A, a composition 13 for the second adhesive layer is applied to the peripheral edge of the light-shielding layer 6 of the cover panel 2 to form a second adhesive layer 8 such that the thickness at the position corresponding to the non-display area 9 decreases in stages from the light-shielding layer 9 side toward the first adhesive layer 7 side. In step B, a composition 11 for the first adhesive layer is applied to the inner circumference of the second adhesive layer 8, and then the surface of the composition 11 for the first adhesive layer is flattened and cured to form the first adhesive layer 7.

[0081] Furthermore, in steps A and B, the second adhesive layer 8 and the first adhesive layer 7 may be formed such that a portion of the coating area of ​​the composition 13 for the second adhesive layer and the composition 11 for the first adhesive layer are mixed.

[0082] In the manufacturing method of the image display device 50 shown in Figure 7, for example, in step A, a second adhesive layer 8 is formed on the periphery of the non-display area 9 of the image panel 4, and a composition 13 for the second adhesive layer is applied to the image display area 3 of the image panel 4 and cured to form a second layer 7B. Then, in step B of the manufacturing method of the image display device 50, a composition having a transmittance of 70% or more for light with a wavelength of 550 nm is applied to the inner periphery of the second adhesive layer 8 and onto the second layer 7B, and cured to form a first layer 7A. As a result, an image display device 50 is obtained that has a first adhesive layer 5 comprising the first layer 7A and the second layer 7B. [Examples]

[0083] The following describes an embodiment of this technology. Note that this technology is not limited to this embodiment. In this embodiment, an evaluation image display device having a configuration similar to the image display device 30 shown in Figure 4 was fabricated, and the transmittance of the second adhesive layer 8 to light with a wavelength of 550 nm and the visibility of the boundary 10 when the display is not lit (seamless effect) were confirmed.

[0084] For example, the following compositions were used as composition 13 for the second adhesive layer and composition 11 for the first adhesive layer. In Table 1, "resin viscosity" refers to the viscosity of composition 13 for the second adhesive layer and composition 11 for the first adhesive layer at 25°C, and was measured using a rheometer (HaakeRheoSress600, Thermo Fisher Scientific; measurement conditions: cone rotor, φ=35mm, rotor angle 2°, shear rate 120 (1 / s)). In Table 1, the values ​​for pigment dispersion in the columns for "composition for the first adhesive layer" and "composition for the second adhesive layer" represent the carbon black content (mass%) in the composition. In Table 1, values ​​other than those in the resin viscosity and pigment dispersion columns represent parts by mass.

[0085] [Table 1]

[0086] The image display device for evaluation was fabricated using the following method. First, the composition 13 for the second adhesive layer was applied using an inkjet device 43 so that the thickness of the second adhesive layer 8 in the non-display area 9 of the image panel 4 (component name: liquid crystal display) continuously decreased toward the image display area 3, thereby forming a composition film 44 for the second adhesive layer. The composition film 44 for the second adhesive layer was irradiated with light using a UV lamp (manufactured by HOYA, UV irradiator: H-40AH4) under conditions that resulted in a curing rate of 40%. This formed the second adhesive layer 8 on the periphery of the non-display area 9 of the image panel 4.

[0087] The composition 11 for the first adhesive layer was applied to the inner circumference of the second adhesive layer 8 using an inkjet device 43 to form a composition film 46 for the first adhesive layer. The composition film 46 for the first adhesive layer was irradiated with light using a UV lamp under conditions that resulted in a curing rate of 40%. This formed the first adhesive layer 7.

[0088] Then, the image panel 4, on which the second adhesive layer 8 and the first adhesive layer 7 were formed, was bonded to the light-shielding layer 6 (black printed, outer dimensions 143mm x 293mm, inner dimensions 103mm x 253mm) of the cover panel 2 (component name: glass (143mm x 293mm)) to obtain an image display device for evaluation. Furthermore, by varying the pigment dispersion content in the composition 13 for the second adhesive layer in the range of 0.10 to 0.85% by mass and the resin thickness in the range of 50 to 200 μm, evaluation image display devices with different transmittances of the second adhesive layer 8 to light at a wavelength of 550 nm were also obtained, as shown in Table 2. In addition, by varying the pigment dispersion content in the composition 11 for the first adhesive layer in the range of more than 0% by mass and 0.8% by mass or less and the resin thickness in the range of 50 to 200 μm, evaluation image display devices with different transmittances of the first adhesive layer 7 to light at a wavelength of 550 nm were also obtained, as shown in Table 3.

[0089] [Transmittance] The transmittance of the second adhesive layer 8 to light at a wavelength of 550 nm was measured from the cover panel 2 side of the evaluation image display device 50 using a UV-Vis spectrophotometer (UV-2600, manufactured by Shimadzu Corporation). The results are shown in Table 2. The transmittance of the light-shielding layer 6 to light at a wavelength of 550 nm, measured in the same manner as the second adhesive layer 8, was 0% in the evaluation image display device.

[0090] [Seamless effect] The seamless effect of the boundary 10 in the viewing direction D when the display is not illuminated was visually evaluated when the transmittance of the second adhesive layer 8 for light with a wavelength of 550 nm is a predetermined value shown in Table 2.

[0091] The seamless effect was evaluated as "×" (NG) when there was no seamless effect, "△" (OK) when the seamless effect was low, "〇" (OK) when there was a seamless effect, and "◎" (OK) when the seamless effect was good. In practical terms, a seamless effect of "◎", "〇", or "△" is preferable, "◎" or "〇" is more preferable, and "◎" is particularly preferable. The results are shown in Table 2.

[0092] In Table 2, "-" indicates that the second adhesive layer 8 was not obtained (did not harden) (NG).

[0093] [Color difference △E] The color difference △E of the second adhesive layer 8 was measured relative to the light-shielding layer 6. A UV-Vis-Near-Infrared spectrophotometer (ARSV-LS901, manufactured by JASCO Corporation) was used to measure the color difference △E. The measurement was performed by positioning the evaluation image display device so that the measurement light entered from the cover panel 2 side and aligned with the point to be measured. The measurement mode was reflectance measurement mode, the measurement temperature was 25°C, and the color temperature L was measured. * a * , b * The color difference △E was calculated using the following formula 1. The results are shown in Table 2.

[0094]

number

[0095] In Formula 1, L1 * , a1 * , b1 * represent the measurement results of the light-shielding layer 6 portion, and L2 * , a2 * , b2 * represent the measurement results of the second adhesive layer 8 portion.

[0096]

Table 2

[0097] <00003​​​​​​​​​​​​​​​​​​​​Furthermore, it was found that by providing a first adhesive layer 7 at a position corresponding to the image display area 3, which exhibits a transmittance to light with a wavelength of 550 nm such that the color of the light-shielding layer 6 and the image panel 4 when the light is off are similar, for example, a first adhesive layer 7 with a transmittance of 50-80% to light with a wavelength of 550 nm, the brightness of the image display area 3 when the display is lit can be maintained more effectively.

[0102] Thus, it has been found that the image display device according to this technology makes the boundary between the light-shielding layer 6 and the image display area 3 seamless when the display is not lit, and maintains the brightness of the image display area 3 when the display is lit. [Explanation of Symbols]

[0103] 1. Image display device, 2 cover panels, 3 Image display area, 4 Image Panels, 5 adhesive layer, 6 light shielding layer, 7. First adhesive layer, 7A 1st layer, 7B 2nd layer, 8. Second adhesive layer, 9 hidden area, 10. Boundary between the light-shielding layer and the image display area, 11 Composition for the first adhesive layer, 12 The boundary between the second adhesive layer and the first adhesive layer, 13 Composition for the second adhesive layer, 20 Image display devices, 30 Image display devices, 40 Image display devices, 40A Image Display Device, 41. Vehicle instrument panel, 42 Housing, 43. Inkjet device, 44 Composition film for the second adhesive layer, 45 light source, 46 Composition film for the first adhesive layer, 50 Image display devices, 100 image display devices, 101 Cover Panel, 102 Light blocking layer, 103 Image display device, 104 Boundary between light-shielding layer and image display area

Claims

1. Cover panel and, An image panel having an image display area and a hidden area, A light-shielding layer provided at a position corresponding to the periphery of the non-display area of ​​the cover panel, The cover panel comprises an adhesive layer that joins the light-shielding layer side with the image panel, The adhesive layer is A first adhesive layer is provided at a position corresponding to the image display area and exhibits transmittance to light with a wavelength of 550 nm such that the color of the image panel when the light is off is similar to that of the light-shielding layer. An image display device comprising a second adhesive layer that is in contact with the light-shielding layer and the first adhesive layer, and is provided around the first adhesive layer, having a transmittance to light with a wavelength of 550 nm that is higher than that of the light-shielding layer and a transmittance to light with a wavelength of 550 nm that is lower than that of the first adhesive layer.

2. The image display device according to claim 1, wherein the first adhesive layer has a transmittance of 50 to 80% for light with a wavelength of 550 nm.

3. The light-shielding layer has a transmittance of 0% for light with a wavelength of 550 nm. The image display device according to claim 1 or 2, wherein the second adhesive layer has a transmittance of 70% or less to light with a wavelength of 550 nm.

4. The image display device according to claim 1 or 2, wherein the second adhesive layer is formed such that its thickness at the position corresponding to the non-display area decreases continuously or stepwise from the light-shielding layer side toward the first adhesive layer side.

5. The image display device according to claim 1 or 2, wherein the second adhesive layer has a transmittance to light with a wavelength of 550 nm on the light-shielding layer side that is smaller than the transmittance to light with a wavelength of 550 nm on the first adhesive layer side.

6. The first adhesive layer is The first layer has a transmittance of 70% or more for light with a wavelength of 550 nm, The image display device according to claim 1 or 2, further comprising a second layer having a higher transmittance to light with a wavelength of 550 nm than the light-shielding layer and a lower transmittance to light with a wavelength of 550 nm than the first layer.

7. The image display device according to claim 6, wherein the second layer has a transmittance of 70% or less for light with a wavelength of 550 nm.

8. Step A involves applying a composition for a second adhesive layer to the periphery of the non-display area of ​​an image panel having an image display area and a non-display area, or to the periphery of a light-shielding layer provided at a position corresponding to the periphery of the non-display area of ​​a cover panel, and curing it to form a second adhesive layer. Step B involves applying the composition for the first adhesive layer to the inner circumference of the second adhesive layer and curing it to form the first adhesive layer. The process includes step C of bonding the light-shielding layer side of the cover panel to the image panel, The first adhesive layer exhibits a transmittance to light with a wavelength of 550 nm such that the color of the image panel when the light is off is similar to that of the light-shielding layer. A method for manufacturing an image display device, wherein the second adhesive layer is in contact with the light-shielding layer and the first adhesive layer, and is provided around the first adhesive layer, and has a higher transmittance to light with a wavelength of 550 nm than the light-shielding layer, and a lower transmittance to light with a wavelength of 550 nm than the first adhesive layer.

9. The method for manufacturing an image display device according to claim 8, wherein the first adhesive layer has a transmittance of 50 to 80% for light with a wavelength of 550 nm.

10. The light-shielding layer has a transmittance of 0% for light with a wavelength of 550 nm. The method for manufacturing an image display device according to claim 8 or 9, wherein the second adhesive layer has a transmittance of 70% or less to light with a wavelength of 550 nm.

11. The method for manufacturing an image display device according to claim 8 or 9, wherein in step A and step B, at least one of the composition for the second adhesive layer and the composition for the first adhesive layer is applied using an inkjet device.

12. The composition for the second adhesive layer and the composition for the first adhesive layer are photocurable compositions. In step A, the composition of the second adhesive layer is cured by light irradiation. The method for manufacturing an image display device according to claim 11, wherein in step B, the composition for the first adhesive layer is cured by light irradiation.

13. In step A, the second adhesive layer is formed on the periphery of the non-display area of ​​the image panel, and the composition for the second adhesive layer is applied to the image display area of ​​the image panel and cured to form a second layer having a higher transmittance to light with a wavelength of 550 nm than the light-shielding layer and a lower transmittance to light with a wavelength of 550 nm than the first adhesive layer. The method for manufacturing an image display device according to claim 7 or 8, wherein in step B, a composition having a transmittance of 70% or more to light with a wavelength of 550 nm is applied to the inner circumference of the second adhesive layer and onto the second layer, and the mixture is cured to form a first layer, thereby forming the first adhesive layer comprising the first layer and the second layer.

14. The method for manufacturing an image display device according to claim 13, wherein the second layer has a transmittance of 70% or less for light with a wavelength of 550 nm.

15. A vehicle instrument panel comprising an image display device according to claim 1 or 2, incorporated within a black housing.

Images