JP7632174B2 - Low-reflection member, display device with low-reflection member - Google Patents

Description

This disclosure relates to a low-reflection member and a display device with a low-reflection member having the low-reflection member.

For example, a low-reflection member is known, as described in Patent Document 1. Such a low-reflection member is disposed facing the display surface of the display device. This makes it possible to prevent the reflection of external light on the display surface from being observed from the outside.

JP 2020-015223 A

In order to give the display surface of the display device an appearance that is integrated with the surrounding area of the display device, the low-reflection member not only faces the display surface, but also covers the surrounding area of the display device. The low-reflection member may have a complex shape around the periphery of the display device due to the arrangement of other components. In this case, the substrate of the low-reflection member may be made of different materials for the part facing the display surface and the part around the periphery of the display device. Different materials may have different refractive indices. This difference in refractive index may result in differences in the appearance of the low-reflection member.

The purpose of this disclosure is to suppress differences in appearance in low-reflection components that have substrates with different refractive indices.

The low-reflection member of the present disclosure is
A first substrate;
a second substrate adjacent to the first substrate in a plan view;
A decorative layer laminated on the first substrate and the second substrate;
A low-reflection member including the decorative layer and a low-reflection layer laminated on the first substrate and the second substrate,
The low-reflection layer is provided on a surface of the low-reflection member,
The refractive index of the first substrate is smaller than the refractive index of the second substrate.

In the low-reflection member of the present disclosure, the low-reflection layer may be laminated on the side of the decorative layer opposite the first substrate and the second substrate.

In the low-reflection component of the present disclosure, the visible light transmittance of the decorative layer may be 70% or less.

In the low-reflection member of the present disclosure,
The decorative layer has a first portion in contact with the first substrate and a second portion in contact with the second substrate,
The refractive index of the first portion may be different from the refractive index of the second portion.

In the low-reflection member of the present disclosure,
The decorative layer further includes a base material supporting the first portion and the second portion,
a refractive index of the first portion is between a refractive index of the first substrate and a refractive index of the base material;
The refractive index of the second portion may be between the refractive index of the second substrate and the refractive index of the base material.

In the low-reflection member of the present disclosure, the decorative layer may include a dark layer that absorbs some of the light incident at each position while transmitting other parts.

In the low-reflection member of the present disclosure, the decorative layer may include a pattern layer that transmits at least a portion of the light incident at each position.

In the low-reflection member of the present disclosure, the decorative layer may include a pattern portion that forms a design, and a transparent portion that is a non-forming portion of the pattern portion.

The visible light transmittance of the low-reflection component of the present disclosure may be 10% or more and 70% or less.

The Y value in the Yxy color system of the low-reflection component of the present disclosure may be less than 3%.

At each position of the low reflection member of the present disclosure, the absolute value of a ^* may be less than 4 and the absolute value of b ^* may be less than 4 in the L ^* a ^* b ^* color system.

In the low-reflection member of the present disclosure, a portion of the second substrate may extend to cover a portion of the first substrate.

The low-reflection member of the present disclosure is
A transparent adhesive layer is provided between the first substrate and the second substrate,
The refractive index of the transparent adhesive layer may be between the refractive index of the first substrate and the refractive index of the second substrate.

The display device with a low-reflection member according to the present disclosure includes:
A display device having a display surface;
and any one of the low-reflection members described above that is arranged so that the first substrate faces the display surface.

According to the present disclosure, it is possible to suppress differences in appearance in low-reflection components having substrates with different refractive indices.

FIG. 1 is an exploded perspective view that shows a schematic overall view of a display device with a low reflection member. FIG. 2 is a cross-sectional view showing an example of a display device. FIG. 3 is a front view showing an example of a display device. FIG. 4 is a cross-sectional view of a display device with a low reflection member. FIG. 5 is a diagram showing a state in which the display device with a low reflection member emits image light. FIG. 6 is a diagram showing a state in which the display device with a low reflection member is not emitting image light. FIG. 7 is a cross-sectional view showing a modified example of the low-reflection member. FIG. 8 is an enlarged front view of the low reflection member of FIG. FIG. 9 is a cross-sectional view showing a modified example of the first substrate and the second substrate. FIG. 10 is a cross-sectional view of a low-reflection member according to another modified example. FIG. 11 is a cross-sectional view of a low-reflection member according to a reference example. FIG. 12 is a cross-sectional view of a low-reflection member according to a comparative example.

An embodiment of the present disclosure will be described below with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios have been appropriately altered and exaggerated from those of the actual objects for the convenience of illustration and ease of understanding.

In this specification, the terms "layer," "sheet," and "film" are not distinguished from one another solely on the basis of differences in name. For example, the term "layer" is a concept that includes members that may be called sheets or films.

In this specification, the term "sheet surface (plate surface, film surface)" refers to a surface that coincides with the planar direction of the target sheet-like (plate-like, film-like) member when the target sheet-like (plate-like, film-like) member is viewed overall and globally.

In this specification, "planar view" means observation from the normal direction of the sheet surface (plate surface, film surface) of the target component.

Terms used in this specification that specify shapes and geometric conditions as well as their degrees, such as "parallel," "orthogonal," and "same," as well as values of lengths and angles, are intended to be interpreted without being bound by strict meanings, but to include a range within which similar functions can be expected.

Figure 1 is an exploded perspective view that shows a schematic diagram of a display device 1 with a low-reflection member according to the present embodiment. As shown in Figure 1, the display device 1 with a low-reflection member has a display device 5 and a low-reflection member 10. The display device 5 has a display surface 6 that displays an image. The low-reflection member 10 is disposed facing the display surface 6 of the display device 5.

In the illustrated example, the display device 1 with a low-reflection member is shown as a flat plate. However, the display device 1 with a low-reflection member may be curved by curving each component of the display device 1 with a low-reflection member. For example, only the low-reflection member 10 may be curved, or the display surface 6 of the display device 5 and the low-reflection member 10 may be curved.

The display device 5 can display an image on the display surface 6. The display device 5 can emit image light from the display surface 6. The display device 5 can be in a state where an image is displayed on the display surface 6, and a state where an image is not displayed on the display surface 6. Any display device such as a liquid crystal display, a plasma display, or an organic electroluminescence display can be used as the display device 5. The display surface 6 of such a display device 5 is typically a glass surface.

Alternatively, the display device 5 may display an image of light and dark by blocking part of the light with a light blocking material. In this case, the display device 5 includes a light source 5a that emits light and a light blocking material 5b that forms an image by blocking part of the light from the light source 5a, as shown in FIG. 2. The light blocking material 5b has a shape corresponding to the image to be displayed. In the example shown in FIG. 3, the light blocking material 5b has a shape corresponding to the shape of "A". The shape of "A" can be displayed by transmitting the light from the light source 5a through the part where the light blocking material 5b is not provided. The non-formed part of the light blocking material 5b becomes the display surface 6. As the light source 5a, it is preferable to use, for example, a surface light source device that emits light in a planar shape in order to make the intensity of the light that passes through the part where the light blocking material 5b is not formed uniform. The light blocking material 5b may be formed integrally with the low-reflection member 10.

Figure 4 shows a cross-sectional view of an example of a display device 1 with a low-reflection member. The low-reflection member 10 is provided so as to cover the display device 5 and the periphery of the display device 5. The low-reflection member 10 protects the display device 5 and the periphery of the display device 5 from the outside, and gives the display device 5 and the periphery of the display device 5 an integrated appearance. As an example, the low-reflection member 10 is provided on the instrument panel of a moving body such as an automobile. In this case, the instrument panel is provided with protrusions and openings such as display devices such as gauges, switches, and air conditioning outlets. The low-reflection member 10 is provided on the entire instrument panel, facing the display device, except for the protrusions and openings. In the vicinity of the protrusions and openings, the low-reflection member 10 has a complex shape. In the example shown in Figure 1, the low-reflection member 10 has a portion with multiple holes.

As shown in FIG. 4, the low-reflection member 10 has a first substrate 11, a second substrate 12, a low-reflection layer 15, and a decorative layer 20. The low-reflection layer 15 is laminated on the decorative layer 20 and the first substrate 11 and the second substrate 12. In the example shown in FIG. 4, the decorative layer 20 is disposed between the low-reflection layer 15 and the first substrate 11 and the second substrate 12 in the low-reflection member 10. In other words, the decorative layer 20 is laminated on the first substrate 11 and the second substrate 12, and the low-reflection layer 15 is laminated on the side of the decorative layer 20 opposite the first substrate 11 and the second substrate 12. The low-reflection member 10 is disposed so that the first substrate 11 faces the display surface 6 of the display device 5.

The first substrate 11 protects the display device 5 and the periphery of the display device 5 from the outside. Typically, the first substrate 11 is larger than the second substrate 12 and is provided on most of the low-reflection member 10. In the example shown in FIG. 1, the first substrate 11 is provided on a portion of the low-reflection member 10 except for the vicinity of the portion where the multiple holes are provided. The first substrate 11 supports the low-reflection layer 15 and the decorative layer 20. The first substrate 11 is a transparent plate-like member. The refractive index of the first substrate 11 is smaller than the refractive index of the second substrate 12. Specifically, the refractive index of the first substrate 11 is, for example, 1.55 or less. The thickness of the first substrate 11 is, for example, 0.5 mm or more and 10 mm or less. The first substrate 11 is made of, for example, glass.

The second substrate 12 is provided in a portion where the low-reflection member 10 has a complex shape, such as near a protruding portion or an opening of the instrument panel. In the example shown in FIG. 1, the second substrate 12 is provided in a portion where a plurality of holes are provided in the low-reflection member 10. The second substrate 12 protects from the outside the peripheral portion of the display device 5 that is difficult to protect with the first substrate 11 made of glass or the like. The second substrate 12 is adjacent to the first substrate 11 in a plan view. Preferably, the second substrate 12 is adjacent to the first substrate 11 without a gap in a plan view. The second substrate 12 supports the low-reflection layer 15 and the decorative layer 20. The second substrate 12 is a transparent plate-like member. The refractive index of the second substrate 12 is, for example, 1.56 or more. The thickness of the second substrate 12 is, for example, 1 mm or more and 10 mm or less. The second substrate 12 is made of, for example, polycarbonate, acrylic, ABS (acrylonitrile butadiene styrene copolymer), or the like.

Transparent means that the visible light transmittance, specified as the average value of the transmittance of the material at each wavelength, is 80% or more when measured using a spectrophotometer (JASCO Corporation's "V-670", compliant with JIS K 0115) within the measurement wavelength range of 380 nm to 780 nm.

The refractive index value can be measured, for example, with an Abbe refractometer (such as the RX-7000α manufactured by Atago Co., Ltd.). The magnitude relationship between the refractive indices can be confirmed, for example, by the refraction direction of light incident on the interface between the materials whose refractive indices are being compared, or by the total reflection conditions.

The low-reflection layer 15 prevents light reflected by the low-reflection member 10 from being observed from the outside. The low-reflection layer 15 is provided on the surface of the low-reflection member 10. The low-reflection layer 15 includes multiple layers with different refractive indices. The light reflected at the interface between the layers with different refractive indices interferes with each other to weaken each other, thereby preventing the light reflected at the surface of the low-reflection member 10 from being observed. The low-reflection layer 15 is transparent. The thickness of the low-reflection layer 15 is, for example, 0.8 nm to 1 μm. The low-reflection layer 15 can be formed, for example, by placing an ultraviolet-curing resin such as urethane acrylate on a substrate such as acrylic or triacetyl cellulose (TAC) and curing the resin by irradiating it with ultraviolet light, and then placing an acrylic ultraviolet-curing resin and curing the resin by irradiating it with ultraviolet light.

The decorative layer 20 displays a design. Due to this design, a portion of the light passing through the decorative layer 20 is absorbed by the decorative layer 20. In other words, the visible light transmittance of the decorative layer 20 is low. Specifically, the visible light transmittance of the decorative layer 20 is 70% or less, and preferably 50% or less.

The decorative layer 20 displays a design, thereby imparting a design to the low-reflection member 10. In the example shown in FIG. 4, the decorative layer 20 has a base material 21, a pattern layer 22, a dark color layer 23, and an adhesive layer 30. The adhesive layer 30 has a first portion 31 and a second portion 32. The decorative layer 20 contacts the first substrate 11 at the first portion 31, and contacts the second substrate 12 at the second portion 32.

In the example shown in FIG. 4, the low-reflection layer 15, the base material 21 of the decorative layer 20, the pattern layer 22, and the dark layer 23 are each integral along the sheet surface as a whole. However, the low-reflection layer 15, the base material 21 of the decorative layer 20, the pattern layer 22, and the dark layer 23 may be separated at the positions where they overlap the first portion 31 and the second portion 32, respectively. In other words, the low-reflection member 10 may be made of a first low-reflection member and a second low-reflection member. In this case, the first low-reflection member has a first low-reflection layer, a first decorative layer having a first base material, a first pattern layer, a first dark layer, and a first portion of the adhesive layer, and a first substrate. The second low-reflection member has a second low-reflection layer, a second decorative layer having a second base material, a second pattern layer, a second dark layer, and a second portion of the adhesive layer, and a second substrate.

In the example shown in FIG. 4, the decorative layer 20 is arranged so that the side on which the dark color layer 23 is provided with respect to the pattern layer 22 faces the display device 5. In other words, the display device 5 is arranged on the side on which the dark color layer 23 of the decorative layer 20 covers the pattern layer 22. However, the decorative layer 20 may be arranged so that the side on which the pattern layer 22 is provided with respect to the dark color layer 23 faces the display device 5. In other words, the display device 5 may be arranged on the side opposite to the side on which the dark color layer 23 of the decorative layer 20 covers the pattern layer 22.

The substrate 21 is a support that properly supports the pattern layer 22 and the dark layer 23. The substrate 21 allows the decorative layer 20 to have an appropriate thickness. The substrate 21 is a transparent film-like member. Considering transparency and proper support for the pattern layer 22 and the dark layer 23, the substrate 21 preferably has a thickness of 10 μm or more and 500 μm or less. The refractive index of the substrate 21 is, for example, 1.4 or more and 1.6 or less. The substrate 21 is made of, for example, polyethylene terephthalate, polycarbonate, acrylic, triacetyl cellulose (TAC), etc.

The picture layer 22 forms the design displayed by the decorative layer 20. More specifically, a design that can be observed from the outside is formed by reflecting a portion of the light incident from the outside at each position of the picture layer 22. The picture layer 22 can form pictures such as figures, patterns, designs, colors, pictures, photographs, characters, marks, pictograms, letters, and numbers as designs.

The pattern layer 22 contains pigments of various colors and organic fillers so that the design can be appropriately formed. In particular, the pigment contained in the pattern layer 22 is preferably an optical interference pigment. Examples of optical interference pigments include pigments coated on scaly base particles such as mica, aluminum, and glass. Titanium oxide is preferable as a pigment that coats the base particles. Optical interference pigments can express a desired color by multiple reflection of light.

The pattern layer 22 can transmit at least a portion of the light incident at each position. This allows the pattern layer 22 to transmit the image light from the display device 5 at each position. The pattern layer 22 may have a portion that transmits all of the light incident thereon. In other words, a portion of the pattern layer 22 may be transparent.

The dark layer 23 makes it difficult to observe the display device 5 from the outside. The dark layer 23 covers the pattern layer 22 from one side, making the design formed by the pattern layer 22 darker and clearer. The dark layer 23 absorbs a part of the light incident at each position while transmitting the other part. The dark layer 23 typically contains a black pigment to be black. The dark layer 23 may contain a black dye instead of a black pigment, or may contain both a pigment and a dye. Examples of the black pigment contained in the dark layer 23 include carbon black, titanium black, and composite metal oxides, and examples of the black dye include azo-based black dye and nigrosine black dye. The dark layer 23 may also contain not only a black pigment and a black dye, but also a toning pigment and a toning dye. For example, if the dark layer 23 containing a black pigment is reddish, the dark layer 23 may further contain a blue pigment as a toning pigment. Alternatively, the dark layer 23 may be black by containing pigments and dyes of the colors yellow, cyan, and magenta. The pigments contained in the dark layer 23 preferably have a particle size of 300 nm or less. The particle size of the pigment can be measured by a laser diffraction method using, for example, a concentrated particle size analyzer (Otsuka Electronics Co., Ltd.'s "FPAR-1000") on the coating liquid that forms the dark layer 23, which will be described later.

The adhesive layer 30 adheres the decorative layer 20 to the first substrate 11 and the second substrate 12. The adhesive layer 30 has a first portion 31 and a second portion 32. The adhesive layer 30 is a so-called OCA (Optical Clear Adhesive). Examples of materials for the adhesive layer 30 include acrylic polymers, urethane polymers, silicone polymers, and rubber elastic polymers. The adhesive layer 30 has a thickness that provides sufficient adhesion and prevents the decorative layer 20 from becoming too thick. For example, the thickness of the adhesive layer 30 is 5 μm or more and 300 μm or less.

The first portion 31 is in contact with the first substrate 11, and the second portion 32 is in contact with the second substrate 12. The refractive index of the first portion 31 is different from that of the second portion 32. The refractive index of the first portion 31 is between the refractive index of the first substrate 11 and the refractive index of the base material 21. In other words, from the side of the low-reflection layer 15 of the low-reflection member 10, the refractive index is higher or lower in the order of the base material 21, the first portion 31, and the first substrate 11. The refractive index of the second portion 32 is between the refractive index of the second substrate 12 and the refractive index of the base material 21. In other words, from the side of the low-reflection layer 15 of the low-reflection member 10, the refractive index is higher or lower in the order of the base material 21, the second portion 32, and the second substrate 12. The refractive index of the first portion 31 is, for example, 1.45 or more and 1.55 or less. The refractive index of the second portion 32 is, for example, 1.5 or more and 1.6 or less.

Not limited to the illustrated example, the pattern layer 22 or the dark color layer 23 may be omitted in the decorative layer 20. If the pattern layer 22 is omitted, the design displayed by the decorative layer 20 will be a dark design formed by the dark color layer 23.

Not limited to the illustrated example, the adhesive layer 30 may be omitted in the decorative layer 20. In this case, the dark color layer 23 has adhesiveness and adheres the decorative layer 20 to the first substrate 11 and the second substrate 12. Such a dark color layer 23 is, for example, an OCA that contains a pigment or dye and has a black color. The dark color layer 23 has a first portion 31 and a second portion 32, similar to the adhesive layer 30 described above. Even in this case, the first portion 31 contacts the first substrate 11, and the second portion 32 contacts the second substrate 12.

If the visible light transmittance of the low-reflection member 10 is too low, the image light from the display device 5 cannot be properly transmitted through the low-reflection member 10, making it difficult to observe the image light. In order to properly observe the image light from the display device 5, the visible light transmittance of the low-reflection member 10 is preferably 2% or more, and more preferably 10% or more. In particular, when the display device 5 is a liquid crystal display, plasma display, organic EL display, etc., in order to properly transmit the image light, the visible light transmittance of the low-reflection member 10 is more preferably 30% or more, and even more preferably 50% or more.

On the other hand, if the visible light transmittance of the low-reflective member 10 is too high, external light is not sufficiently reflected by the pattern layer 22 of the low-reflective member 10, and the low-reflective member 10 cannot properly display the design formed by the decorative layer 20. To properly display the design, the visible light transmittance of the low-reflective member 10 is preferably 70% or less, and more preferably 40% or less.

Visible light transmittance is determined as the average value of the transmittance at each wavelength when measured using a spectrophotometer (JASCO Corporation's "V-670", compliant with JIS K 0115) in the measurement wavelength range of 380 nm to 780 nm.

When the saturation of the low-reflection member 10 is high, the light passing through the low-reflection member 10 may change from the intended color. That is, the image light from the display device 5 may not be properly observed. It is preferable that the saturation of the low-reflection member 10 is low so that the image light passes through the low-reflection member 10 with almost no change in color. Specifically, it is preferable that the absolute value of a ^* in the L ^* a ^* b ^* color system is 4 or less and the absolute value of b ^* is 4 or less.

The L ^* , a ^* , and b ^* values in the L ^* a ^* b ^* color system can be measured from the reflectance of total reflection including specular reflection (SCI) at an object using, for example, a spectrophotometer (Konica Minolta's "CM-700d").

The luminous reflectance Y value of the low-reflection member 10 in the Yxy color system is sufficiently low. Specifically, the luminous reflectance Y value of the low-reflection member 10 is preferably less than 3%, and more preferably less than 1.5%.

The value of luminous reflectance Y is a value specified in JIS Z8722, and means the reflectance of total reflection including specular reflection for light with a wavelength of about 550 nm (SCI). For example, a spectrophotometer (Konica Minolta's "CM-700d") can be used as a device for measuring the value of luminous reflectance Y.

An example of a method for manufacturing the low-reflection member 10 is described below.

A first substrate 11 and a second substrate 12 are prepared, each having a shape corresponding to the component on which the low-reflection member 10 to be manufactured is to be placed. The first substrate 11 is made of, for example, glass, and is provided on the main portion of the component having a shape corresponding to the component on which the low-reflection member 10 is to be placed. The second substrate 12 is made of, for example, polycarbonate, and is provided on the portion on which the low-reflection member 10 will have a complex shape. The second substrate 12 can be manufactured into a desired shape, for example, by injection molding. This allows the second substrate 12 to have a complex shape. A first portion 31 of an adhesive layer 30 is provided on the first substrate 11. A second portion 32 of an adhesive layer 30 is provided on the second substrate 12.

A coating liquid for forming a dark layer 23 is applied onto the substrate 21. The coating liquid contains black pigments such as carbon black, titanium black, and composite metal oxides, and black dyes such as azo-based black dyes and nigrosine black dyes. The coating liquid may contain a toning pigment or a toning dye. Alternatively, the coating liquid may contain pigments or dyes of yellow, cyan, and magenta to be black. The particle size of the pigments contained in the coating liquid is 300 nm or less. The coating liquid is made of, for example, an ultraviolet-curing resin. When the coating liquid is irradiated with ultraviolet light, the coating liquid hardens and the dark layer 23 is formed.

A pattern layer 22 is provided on the dark layer 23, for example by printing. The pattern layer 22 is provided so as to form a desired design. The pattern layer 22 is provided, for example, thin enough so as to transmit at least a portion of the light incident at each position.

An adhesive layer 30 is provided on the side of the substrate 21 opposite the side on which the dark layer 23 is provided. In addition, a low-reflection layer 15 is provided on the pattern layer 22. This produces the low-reflection member 10 shown in FIG. 4.

The function of the display device 1 with low-reflection member and the low-reflection member 10 of this embodiment will be explained.

When no image is displayed on the display surface 6 of the display device 5, the low-reflection member 10 displays a design in the display device 1 with a low-reflection member, as shown in FIG. 5. The design displayed by the low-reflection member 10 is displayed on the display device 5 and its periphery. This allows the display device 5 and its periphery to have a unified appearance.

On the other hand, when the display device 5 displays an image on the display surface 6, as shown in FIG. 6, the image light passes through the low-reflection member 10. More specifically, a portion of the incident image light is passed through each position of the pattern layer 22 and the dark color layer 23 of the decorative layer 20. This allows the observer to observe the image. In other words, the display device 1 with low-reflection member can display the image that is intended to be observed, and an external observer can observe the image. In particular, since the image light can be passed through each position of the low-reflection member 10, the display device 1 with low-reflection member can display the image clearly.

Light incident on the display device with low-reflection member 1 from the outside first enters the low-reflection layer 15 of the low-reflection member 10. The light reflected at the surface and internal interfaces of the low-reflection layer 15 weaken each other. For this reason, even if light enters the display device with low-reflection member 1 from the outside, the light reflected by the display device with low-reflection member 1 is hardly observed.

In the low-reflection component, a substrate made of glass is used. The low-reflection component may include a portion with a complex shape. It is difficult to fabricate a substrate made of glass that conforms to a complex shape. In the portion with a complex shape, a resin such as polycarbonate is used as the substrate. A substrate made of resin can be easily fabricated to conform to a complex shape. In this case, substrates made of different materials are adjacent in a planar view. Different materials may have different refractive indices. This difference in refractive index may cause a difference in appearance between portions of the base material made of different materials.

The low-reflection member 10 of this embodiment has a decorative layer 20 laminated on the first substrate 11 and the second substrate 12, and a low-reflection layer 15 laminated on the decorative layer 20 and the first substrate 11 and the second substrate 12. The low-reflection layer 15 provided on the surface of the low-reflection member 10 makes it difficult to observe light reflected at the interface between the low-reflection layer 15 and other members. It is possible to reduce light incident on members other than the low-reflection layer 15. Therefore, less light is reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12. Even if there is a difference in the refractive index between the first substrate 11 and the second substrate 12, the difference in appearance between the first substrate 11 and the second substrate 12 is difficult to observe.

In the example shown in FIG. 4, the low-reflection layer 15 is laminated on the side of the decorative layer 20 opposite to the first substrate 11 and the second substrate 12. The low-reflection layer 15 makes it difficult to observe light reflected at the interface between the low-reflection layer 15 and the decorative layer 20. The amount of light incident on the decorative layer 20 can be reduced. Therefore, less light is reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12. After passing through the decorative layer 20, the light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 passes through the decorative layer 20 again and exits from the low-reflection member 10. That is, the light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 passes through the decorative layer 20 twice. The decorative layer 20 has a low visible light transmittance in order to display the design. For this reason, light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 is difficult to observe. For these reasons, even if there is a difference in the refractive index between the first substrate 11 and the second substrate 12, the difference in appearance between the first substrate 11 and the second substrate 12 is difficult to observe.

The visible light transmittance of the decorative layer 20 is 70% or less. In the example shown in FIG. 4, the light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 passes through the decorative layer 20 twice, and is reduced to 50% or less by the decorative layer 20. For this reason, the light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 is difficult to observe. Therefore, the difference in appearance between the first substrate 11 and the second substrate 12 is even more difficult to observe.

The refractive index of the first portion 31 is different from the refractive index of the second portion 32. The refractive index of the portion of the decorative layer 20 in contact with the first substrate 11 and the second substrate 12 is adjusted to match the first substrate 11 and the second substrate 12, respectively. This makes it possible to reduce the reflectance at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12. In particular, the refractive index of the first portion 31 is between the refractive index of the first substrate 11 and the refractive index of the base material 21, and the refractive index of the second portion 32 is between the refractive index of the second substrate 12 and the refractive index of the base material 21, so that the reflectance at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 can be reduced. As a result, the light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 becomes difficult to observe.

The visible light transmittance of the low-reflective member 10 is 10% or more and 70% or less. Because the visible light transmittance is sufficiently low, the low-reflective member 10 can properly display the design by the decorative layer 20. Because the visible light transmittance is sufficiently high, the low-reflective member 10 can transmit sufficient light at each position, so the light passing through the low-reflective member 10 becomes clear.

The value of the visual reflectance Y in the Yxy color system of the low-reflection member 10 is less than 3%. Because the visual reflectance of the low-reflection member 10 as a whole is sufficiently small, even if there is a difference between the visual reflectance at the position where it overlaps the first substrate 11 and the visual reflectance at the position where it overlaps the second substrate 12, the difference is small and there is almost no difference in appearance. Therefore, the difference in appearance between the first substrate 11 and the second substrate 12 is less easily observed.

At each position on the low-reflection member 10, the absolute value of a ^* in the L ^* a ^* b ^* color system is 4 or less, and the absolute value of b ^* is 4 or less. That is, the saturation of the low-reflection member 10 is low. Therefore, light passing through the low-reflection member 10, particularly image light from the display device 5, can be easily observed in the intended color even through the low-reflection member 10. That is, the image light can be appropriately observed.

As described above, the low-reflection member 10 of the present embodiment includes the first substrate 11, the second substrate 12 adjacent to the first substrate 11 in a plan view, the decorative layer 20 laminated on the first substrate 11 and the second substrate 12, and the low-reflection layer 15 laminated on the decorative layer 20 and the first substrate 11 and the second substrate 12, and the low-reflection layer 15 is provided on the surface of the low-reflection member 10, and the refractive index of the first substrate 11 is smaller than that of the second substrate 12. With such a low-reflection member 10, the amount of light incident on members other than the low-reflection layer 15 is reduced, so that light reflected at the interface between the decorative layer 20 and the first substrate 11 or the second substrate 12 is difficult to observe. Therefore, the difference in appearance between the first substrate 11 and the second substrate 12 is difficult to observe.

Various modifications can be made to the above-described embodiment. Below, we will explain modified examples of the low-reflection member 10 with reference to the figures.

A modified example of the decorative layer 20 is shown in Figures 7 and 8. Figure 7 corresponds to Figure 4 and shows a cross-sectional view of a display device 1 with a low-reflection member having a decorative layer 20 in one modified example. Figure 8 is an enlarged front view of the low-reflection member 10 in the display device 1 with a low-reflection member of Figure 7. The components other than the decorative layer 20 are the same as those in the embodiment described above, and detailed description will be omitted.

The decorative layer 20 shown in FIG. 7 has a base material 21, a patterned portion 26, a dark colored portion 27, a transparent portion 28, and an adhesive layer 30. The transparent portion 28 is a non-formed portion of the patterned portion 26 and the dark colored portion 27. The patterned portion 26 is provided at a position overlapping the dark colored portion 27. In the example shown in FIG. 7, the decorative layer 20 is arranged so that the side on which the dark colored portion 27 is provided with respect to the patterned portion 26 faces the display device 5. However, the decorative layer 20 may be arranged so that the side on which the patterned portion 26 is provided with respect to the dark colored portion 27 faces the display device 5. Not limited to the illustrated example, the patterned portion 26 or the dark colored portion 27 may be omitted. The base material 21 and the adhesive layer 30 are the same as those in the above-mentioned embodiment, so their description will be omitted here.

The pattern portion 26 forms the design displayed by the decorative layer 20, similar to the pattern layer 22 in the embodiment described above. The thickness of the pattern portion 26 is preferably 1 μm or more and 20 μm or less. By making the pattern portion 26 sufficiently thick, the pattern formed by the pattern portion 26 can be made dark and clear. In the example shown in FIG. 7, the cross-sectional shape of the pattern portion 26 is rectangular, but is not limited to this and may be, for example, a trapezoidal shape.

The dark color portion 27 has a function of absorbing light so that the image light from the display device 5 does not enter the pattern portion 26. The dark color portion 27 may contain, for example, light absorbing particles in a binder resin. Examples of light absorbing particles include black pigments such as carbon black and titanium black. It is preferable that the dark color portion 27 is provided only in a position facing the pattern portion 26 so that the image light emitted from the display device 5 is not hindered from passing through the transmission portion 28 by the dark color portion 27. In addition, if the dark color portion 27 is sufficiently thick to cover the pattern portion 26, the pattern formed by the pattern portion 26 becomes darker and clearer. As a specific example, the thickness of the dark color portion 27 is 1 μm or more and 20 μm or less.

The transparent portion 28 is provided to transmit the image light from the display device 5 to the low-reflection member 10. FIG. 8 shows an enlarged portion of a front view of the low-reflection member 10. As shown in FIG. 7 and FIG. 8, the transparent portion 28 is a non-formed portion of the pattern portion 26 and the dark color portion 27 when the low-reflection member 10 is observed from the front, as shown in FIG. 7 and FIG. 8. In order to sufficiently transmit the image light from the display device 5, the proportion of the area occupied by the transparent portion 28 in the decorative layer 20 (also called the aperture ratio) is preferably 5% or more, and more preferably 10% or more. On the other hand, in order to make it easier to observe the design displayed by the decorative layer 20, the proportion of the area occupied by the transparent portion 28 in the decorative layer 20 is preferably 30% or less.

In the example shown in FIG. 8, a plurality of transparent portions 28 are arranged at a distance from each other. A pattern portion 26 is formed between each transparent portion 28. In the illustrated example, each transparent portion 28 is circular when viewed from the front, and the plurality of transparent portions 28 are arranged in a square lattice pattern. When each transparent portion 28 is circular, the diffusion of the image light passing through the transparent portion 28 can be suppressed. In addition, when the transparent portions 28 are arranged in a lattice pattern, particularly in a square lattice pattern, the image light from the display device 5 can be uniformly transmitted, so that unevenness in the image light is less likely to occur. However, the transparent portions 28 are not limited to the illustrated example, and may have any shape and may be arranged in any position. The diameter of each transparent portion 28 is, for example, 30 μm or more and 150 μm or less.

The transmissive portion 28 may be a gap such as a hole, as in the example shown in FIG. 7, but may also be made of, for example, a transparent resin. Such a transparent resin can effectively prevent foreign matter such as dust from entering the transmissive portion 28.

The transparent portion 28 can be formed, for example, by irradiating a laser onto the pattern portion 26 and the dark portion 27 provided over the entire surface of the substrate 21 at the positions where the transparent portion 28 is to be formed, and then removing the pattern portion 26 and the dark portion 27 at the positions irradiated by the laser.

Figure 9 shows a modified example of the first substrate 11 and the second substrate 12 of the decorative layer 20. In this modified example, a portion of the second substrate 12 extends to cover a portion of the first substrate 11. As a result, a portion of the second substrate 12 overlaps with the first substrate 11. Because the second substrate 12 has such a shape, the first substrate 11 can be assembled to the second substrate 12 and positioned in an appropriate position.

The low-reflection member 10 has a transparent adhesive layer 13 provided between the first substrate 11 and the second substrate 12. The transparent adhesive layer 13 bonds the first substrate 11 and the second substrate 12. The refractive index of the transparent adhesive layer 13 is between the refractive index of the first substrate 11 and the refractive index of the second substrate 12. Specifically, the refractive index of the transparent adhesive layer 13 is 1.45 or more and 1.55 or less. The transparent adhesive layer 13 is made of, for example, an acrylic polymer, a urethane polymer, a silicone polymer, a rubber bullet polymer, etc. In the portion where the second substrate 12 extends and covers the first substrate 11, the light is reflected at two interfaces, that is, the interface between the second substrate 12 and the transparent adhesive layer 13, and the interface between the transparent adhesive layer 13 and the first substrate 11. The sum of these reflectances is lower than the reflectance at the interface between the first substrate 11 and the second substrate 12. By providing the transparent adhesive layer 13, the difference in appearance due to the difference in refractive index between the first substrate 11 and the second substrate 12 can be reduced in the portion where the second substrate 12 covers the first substrate 11.

Figure 10 shows another modified example of the low-reflection member 10. In the example shown in Figure 10, the first substrate 11 and the second substrate 12 are arranged between the low-reflection layer 15 and the decorative layer 20 in the low-reflection member 10. In other words, the first substrate 11 and the second substrate 12 are laminated on the decorative layer 20, and the low-reflection layer 15 is laminated on the opposite side of the decorative layer 20 of the first substrate 11 and the second substrate 12. The low-reflection member 10 is arranged so that the decorative layer 20 laminated on the first substrate 11 faces the display surface 6 of the display device 5. In the example shown in Figure 10, the decorative layer 20 has a base material 21, a dark color layer 23, and an adhesive layer 30 having a first portion 31 and a second portion 32, but the pattern layer 22 is omitted. That is, the decorative layer 20 forms a dark design by the dark color layer 23.

Of course, it is possible to combine the embodiments and variations as appropriate.

The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

As Example 1, the low-reflection member 10 of the embodiment shown in FIG. 4 was prepared. As Example 2, the low-reflection member 10 of the above-mentioned modified example shown in FIG. 7 was prepared. As Example 3, the low-reflection member 10 of the above-mentioned modified example shown in FIG. 10 was prepared. As Reference Example 1, a member 110 in which a low-reflection layer 115 was laminated on a first substrate 111 and a second substrate 112 as shown in FIG. 11 was prepared. As Comparative Example 1, a member 110 in which a decorative layer 120 was laminated on a first substrate 111 and a second substrate 112 as shown in FIG. 12 was prepared. In each Example, Reference Example, and Comparative Example, the decorative layer has a base material, a dark color layer or a dark color portion, and an adhesive layer having a first portion and a second portion, but the pattern layer or the pattern portion is omitted. That is, the decorative layer forms a dark color design. In each Example, Reference Example, and Comparative Example, the visible light transmittance of the decorative layer is 50%.

For each of the members of the Examples, Reference Examples, and Comparative Examples, the Y value in the Yxy color system, the L ^* value, the a ^* value, and the ^{b* value} in the L*a ^* b ^* color system were measured at the position overlapping the first substrate and the position overlapping the second substrate. The measurements were performed using a spectrophotometer (Konica Minolta's "CM-700d") to measure the reflectance of total reflection including regular reflection (SCI). For each of the members of the Examples and Comparative Examples, it was visually confirmed whether or not there was a difference in appearance between the position overlapping the first substrate and the position overlapping the second substrate. A was assigned to those in which there was almost no difference in appearance between the position overlapping the first substrate and the position overlapping the second substrate, B was assigned to those in which there was no difference in appearance unless carefully observed, and C was assigned to those in which there was a clear difference in appearance. The measurement results and observation results are shown in Table 1 below.

As can be seen from Table 1, in Examples 1, 2, 3 and Reference Example 1, the differences in the Y value in the Yxy color system, the L ^* value, the a ^* value and the ^{b* value} in the L*a ^* b ^* color system between the position overlapping the first substrate and the position overlapping the second substrate are sufficiently small. That is, it is understood that there is a small difference in appearance between the position overlapping the first substrate and the position overlapping the second substrate. On the other hand, in Comparative Example 1, the differences in the Y value in the Yxy color system, the L ^* value, the a ^* value and the ^{b *} value in the L*a ^* b ^* color system between the position overlapping the first substrate and the position overlapping the second substrate are relatively large. That is, it is considered that there is a difference in appearance between the position overlapping the first substrate and the position overlapping the second substrate. As a result of the observation, no difference in appearance was observed between the position overlapping the first substrate and the position overlapping the second substrate in Examples 1, 2, and 3, but a difference in appearance was observed between the position overlapping the first substrate and the position overlapping the second substrate in Comparative Example 1. In particular, since the value of luminous reflectance Y in the Yxy color system of the low-reflection member 10 in Comparative Example 1 is 3% or more, it is considered that a difference in appearance due to the difference between the luminous reflectance at the position overlapping the first substrate 11 and the luminous reflectance at the position overlapping the second substrate 12 is easily observed.

In Examples 1, 2, and 3, the low-reflection member has a decorative layer, and the decorative layer can display a design. This design makes it difficult to observe differences in appearance. A design can be imparted to the member on which the low-reflection member is provided.

Reference Signs List 1 Display device with low reflection member 5 Display device 6 Display surface 10 Low reflection member 11 First substrate 12 Second substrate 13 Transparent adhesive layer 15 Low reflection layer 20 Decorative layer 21 Base material 22 Design layer 23 Dark color layer 26 Design portion 27 Dark color portion 28 Transmissive portion 30 Adhesive layer 31 First portion 32 Second portion

Claims (14)

A first substrate;
a second substrate adjacent to the first substrate in a plan view;
A decorative layer laminated on the first substrate and the second substrate;
A low-reflection member including the decorative layer and a low-reflection layer laminated on the first substrate and the second substrate,
The low-reflection layer is provided on a surface of the low-reflection member,
A low-reflection member, wherein the refractive index of the first substrate is smaller than the refractive index of the second substrate. The low-reflection member according to claim 1, wherein the low-reflection layer is laminated on the side of the decorative layer opposite the first substrate and the second substrate. The low-reflection member according to claim 1 or 2, wherein the visible light transmittance of the decorative layer is 70% or less. The decorative layer has a first portion in contact with the first substrate and a second portion in contact with the second substrate,
The low-reflection member according to claim 1 , wherein a refractive index of the first portion is different from a refractive index of the second portion. The decorative layer further includes a base material supporting the first portion and the second portion,
a refractive index of the first portion is between a refractive index of the first substrate and a refractive index of the base material;
The low-reflection member according to claim 4 , wherein the refractive index of the second portion is between the refractive index of the second substrate and the refractive index of the base material. The low-reflection member according to any one of claims 1 to 5, wherein the decorative layer includes a dark layer that absorbs part of the light incident at each position while transmitting the other part. The low-reflection member according to any one of claims 1 to 6, wherein the decorative layer includes a pattern layer that transmits at least a portion of the light incident at each position. The low-reflection member according to any one of claims 1 to 5, wherein the decorative layer includes a pattern portion that forms a design and a transparent portion that is a non-forming portion of the pattern portion. The low-reflection member according to any one of claims 1 to 8, wherein the visible light transmittance of the low-reflection member is 10% or more and 70% or less. The low-reflection member according to any one of claims 1 to 9, wherein the Y value in the Yxy color system of the low-reflection member is less than 3%. 11. The low-reflection member according to claim 1, wherein the absolute value of a ^* in the L ^* a ^* b ^* color system is less than 4 and the absolute value of b ^* is less than 4 at each position of the low-reflection member. The low-reflection member according to any one of claims 1 to 11, wherein a portion of the second substrate extends to cover a portion of the first substrate. A transparent adhesive layer is provided between the first substrate and the second substrate,
The low-reflection member according to claim 12 , wherein the refractive index of the transparent adhesive layer is between the refractive index of the first substrate and the refractive index of the second substrate. A display device having a display surface;
A display device with a low-reflection member, comprising: the low-reflection member according to claim 1 , which is disposed so that the first substrate faces the display surface.