Cover plate, decorative sheet and display device

Abstract

The visibility of a display screen, a cover plate or a decorative sheet of a display device at a position where a pattern layer, a transparent or semitransparent matte layer, and a transparent or semitransparent glossy layer overlap is improved. The pattern layer (22) has a pattern colored with an interference pigment (22p) that develops color by interference of reflected light of the second visible light incident on the surface exposed region (EX) from the outside. The glossy layer (24) is disposed on the layer surface (23s) of the matte layer (23). The glossy layer (24) is a layer for forming a convex portion (24p) and a concave portion (24r) in the surface exposed region (EX) so as to increase the surface roughness of the surface exposed region (EX) compared to a case where the glossy layer (24) is not present, and is configured so that the Haze value of the surface exposed region (EX) is 40% to 85%.

Description

Cover plate, decorative panel and display device Technical Field

[0001] The present invention relates to a cover plate with interference pigment, a decorative sheet with interference pigment, and a display device with interference pigment. Background Technology

[0002] Existing display devices use, for example, a patterned layer having a pattern colored with interference pigments as described in Patent Document 1 (Japanese Patent No. 6839319) and Patent Document 2 (Japanese Patent No. 5725581). Patterns colored with interference pigments are not easily visible under transmitted light, but are easily visible under reflected light.

[0003] In such a display device, when visible light emitted from the display screen passes through the pattern colored with interference pigments, the display of the screen is visually recognized without being obstructed by the pattern. Of course, when no visible light is emitted from the display screen of the display device, the pattern colored with interference pigments is visually recognized mainly by visible light incident on the pattern layer from outside the display device.

[0004] For such a display device, for example, it is possible to use a glossy layer (glossy layer) and a matte layer as shown in Patent Document 3 (Japanese Patent Application Publication No. 2000-62081) to give the surface exposed area of ​​the display screen that presents the display content a desired tactile feel.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6839319

[0008] Patent Document 2: Japanese Patent No. 5725581

[0009] Patent Document 3: Japanese Patent Application Publication No. 2000-62081 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] However, when a pattern colored with interference pigments (pattern layer), a highlight layer (gloss layer), and a matte layer are overlaid, the displayed image is less visible compared to the case where the pattern (pattern layer) is not colored with interference pigments. The reason for the reduced visibility and difficulty in seeing the displayed image is believed to be due to the unevenness formed by the matte and gloss layers and the interference pigments in the pattern layer.

[0012] The technical problem of the present invention is to improve the visibility of the display screen, cover plate or decorative piece of the display device at the location where a patterned layer with interference pigment, a transparent or semi-transparent matte layer and a transparent or semi-transparent glossy layer overlap.

[0013] Technical solutions for solving technical problems

[0014] The following describes several aspects as a technical solution to the technical problem. These aspects can be combined arbitrarily as needed.

[0015] The first aspect of the present invention relates to a cover plate disposed on a display screen that emits first visible light to visually display information or images, and positioned on the exposed surface area of ​​a display device through which the first visible light emitted from the display screen passes. The cover plate comprises a transparent or translucent substrate film, a pattern layer, a transparent or translucent matte layer, and a transparent or translucent glossy layer. The transparent or translucent substrate film has a first main surface and a second main surface; the first visible light emitted from the display screen is incident on the first main surface and exits from the second main surface. The pattern layer is disposed on the first main surface side of the substrate film and has a pattern colored with interference pigments, which are colored by interference of reflected light from the second visible light incident from the outside onto the exposed surface area. The matte layer is disposed on the second main surface side of the substrate film and is a layer for matting the light in the exposed surface area. The glossy layer is disposed on the surface of the matte layer. The gloss layer is a layer used to form protrusions and depressions in the exposed surface area, thereby increasing the surface roughness of the exposed surface area compared to the case without a gloss layer. It is configured such that the haze value of the exposed surface area is 40% or more and 85% or less.

[0016] According to the cover plate involved in the first viewpoint, by making the haptic value of the cover plate, including the pattern layer colored with interference pigment, between 40% and 85%, the exposed surface area can be given a tactile feel by the concave and convex parts through the gloss layer, and the visibility of the cover plate can be improved by making the boundary between the convex and concave parts less obvious.

[0017] The cover plate described in the second viewpoint is configured such that, in the cover plate described in the first viewpoint, the recesses and protrusions are composed of a glossy layer having a wavy shape with repeating recesses and protrusions. In the cover plate described in the second viewpoint, the difference in haze values ​​between the protrusions and recesses can be set through the glossy layer, making it easy to set the haze value of the cover plate to an appropriate value and easily improving visibility.

[0018] The cover plate in the third viewpoint, based on the cover plate in the second viewpoint, has a gloss layer configured such that the gradation (grayscale, level) of the recessed area is 30% or more and 60% or less. In the cover plate of the third viewpoint, because the gradation of the recessed area is 30% or more and 60% or less, it becomes a configuration that makes it easy to appropriately set the difference in haze values ​​between the convex and concave areas, thus easily improving visibility.

[0019] The cover plate in the fourth viewpoint, based on the cover plate in the third viewpoint, has a bottom surface of the recess composed of a matte layer. In the cover plate in the fourth viewpoint, the haze value of the bottom surface of the recess can be set to the haze value of the matte layer, making it easy to set the haze value of the recess and easily improve visibility.

[0020] The cover plate in the fifth viewpoint, based on the cover plate in the fourth viewpoint, has a haze value of 65% or higher and 80% or lower in the region of the laminate composed of the substrate film and the matte layer. In the cover plate of the fifth viewpoint, by setting the haze value of the region of the laminate composed of the substrate film and the matte layer to 65% or higher and 80% or lower, it is possible to suppress display blurring and significantly improve visibility.

[0021] The cover plate involved in the sixth point of view is based on the cover plates involved in the first to fifth points of view. The haze value of the cover plate is above 60% and below 70%. Therefore, it can suppress the obvious boundary between the concave and convex parts, suppress the reduction of the display contrast, and significantly improve the visibility.

[0022] The decorative sheet in the seventh viewpoint is a decorative sheet disposed on a display screen that emits first visible light to visually display information or images, and arranged on the exposed surface area of ​​a display device through which the first visible light emitted from the display screen passes. This decorative sheet comprises a transparent or translucent substrate film, a pattern layer, a transparent or translucent matte layer, and a transparent or translucent glossy layer. The substrate film has a first main surface and a second main surface; the first visible light emitted from the display screen is incident on the first main surface and exits from the second main surface. The pattern layer is disposed on the first main surface side of the substrate film and has a pattern colored with interference pigments, which are colored by the interference of reflected light from the second visible light incident from the outside onto the exposed surface area. The matte layer is disposed on the second main surface side of the substrate film and is a layer for matting the light in the exposed surface area. The glossy layer is disposed on the surface of the matte layer. The gloss layer is a layer used to form protrusions and depressions in the exposed surface area, thereby increasing the surface roughness of the exposed surface area compared to the case without a gloss layer. It is configured such that the haze value of the area corresponding to the exposed surface area is 40% or more and 85% or less.

[0023] In the decorative sheet described in the seventh viewpoint, by making the haze value of the decorative sheet, which includes a pattern layer colored with interference pigment, between 40% and 85%, the exposed surface area can be given a tactile feel by the concave and convex parts through the gloss layer, and the visibility of the decorative sheet can be improved by making the boundary between the convex and concave parts less obvious.

[0024] The display device according to the eighth viewpoint includes: a display screen that emits first visible light to visually display information or images; and a cover plate disposed on the exposed surface area of ​​the display screen and allowing the first visible light emitted from the display screen to pass through. The cover plate of the display device includes a transparent or translucent substrate film, a pattern layer, a transparent or translucent matte layer, and a transparent or translucent glossy layer. The substrate film has a first main surface and a second main surface, with the first visible light emitted from the display screen incident on the first main surface and exiting from the second main surface. The pattern layer is disposed on the first main surface side of the substrate film and has a pattern colored with interference pigments, which are colored by interference of reflected light from the second visible light incident from the outside onto the exposed surface area. The matte layer is disposed on the second main surface side of the substrate film and is a layer for extinction of the exposed surface area. The glossy layer is disposed on the surface of the matte layer. The gloss layer is a layer used to form protrusions and depressions in the exposed surface area, thereby increasing the surface roughness of the exposed surface area compared to the case without a gloss layer, and is configured such that the Haze value of the exposed surface area of ​​the cover plate is 40% or more and 85% or less.

[0025] According to the display device described in the eighth point, by making the haptic value of the cover plate, which includes a pattern layer colored with interference pigment, between 40% and 85%, the gloss layer can impart a tactile feel from the recesses and protrusions to the exposed surface area, and can improve the visibility of the cover plate by making the boundary between the protrusions and recesses less obvious.

[0026] Invention Effects

[0027] The visibility of the display screen of the cover plate, decorative plate or display device involved in the present invention is improved. Attached Figure Description

[0028] Figure 1 is a top view of the smartphone involved in the embodiment.

[0029] Figure 2 is a schematic cross-sectional view showing an example of the cover plate according to the first embodiment.

[0030] Figure 3 is a diagram illustrating the relationship between the tone of the concave section and the Haze value.

[0031] Figure 4 is a partial top view showing a portion of the pattern in the patterned layer.

[0032] Figure 5 is a partial top view showing a portion of an example of the pattern of the glossy layer.

[0033] Figure 6 is a partial top view showing a portion of the smartphone's display screen.

[0034] Figure 7 is a schematic diagram illustrating an example of interference pigments used to form patterns.

[0035] Figure 8 is a schematic diagram illustrating the changes in appearance caused by interference pigments.

[0036] Figure 9 is a schematic cross-sectional view showing an example of the cover plate according to the second embodiment.

[0037] Figure 10 is a schematic cross-sectional view used to illustrate the lamination of a decorative sheet involved in a modified example.

[0038] Figure 11 is a schematic cross-sectional view showing a portion of the composition of a smartphone using decorative pieces.

[0039] Figure 12 is a schematic cross-sectional view used to illustrate the lamination of the decorative sheet involved in another variation.

[0040] Figure 13 is a schematic cross-sectional view showing a portion of the composition of a smartphone using decorative pieces.

[0041] Figure 14 is a top view illustrating the bubbles generated during the lamination of decorative sheets.

[0042] Figure 15 is a schematic cross-sectional view showing an example of the cover plate involved in variant C.

[0043] Figure 16 is a schematic cross-sectional view showing an example of the cover plate involved in variant D.

[0044] Figure 17 is a schematic cross-sectional view showing another example of the cover plate involved in variant D.

[0045] Figure 18 is a process diagram showing the manufacturing process of the cover plate involved in Modified Example E.

[0046] Figure 19 is an enlarged illustration of a proxy photograph of the display screen of an existing smartphone with geometric patterns formed by a glossy layer.

[0047] Figure 20 is a photographic representation of an icon showing the display screen of a smartphone with a geometric pattern formed by the glossy layer according to the first embodiment.

[0048] Figure 21 is a photographic illustration showing an enlarged view of the display screen of a smartphone with a geometric pattern formed on the glossy layer according to the second embodiment.

[0049] Figure 22 is an illustrated photograph of an icon showing an enlarged view of the display screen of an existing smartphone with a wood grain pattern formed by a glossy layer.

[0050] Figure 23 is a photographic representation of an icon showing the display screen of a smartphone with a wood grain pattern formed by the gloss layer according to the first embodiment.

[0051] Figure 24 is a photographic representation of an icon showing the display screen of a smartphone with a wood grain pattern formed by the gloss layer according to the second embodiment.

[0052] Figure 25 is an enlarged photograph of an icon pattern of an existing masking layer that forms a wood grain pattern through a glossy layer.

[0053] Figure 26 is a photographic representation of the icon pattern of the first embodiment of the masking layer, which is enlarged to show the wood grain pattern formed by the gloss layer.

[0054] Figure 27 is a photographic representation of the icon pattern of the masking layer in the second embodiment, which is enlarged to show the wood grain pattern formed by the gloss layer. Detailed Implementation

[0055] <First Implementation Method>

[0056] (1) Overall composition

[0057] Figure 1 shows an example of a smartphone 1 as a display device according to the first embodiment of the present invention. Here, smartphone 1 is cited as an example of a display device, but the display device to which the present invention is applied is not limited to smartphone 1; examples include display devices built into mobile computers, display devices for automobiles, and monitors for various devices. Among display devices for automobiles, examples include monitors for automobile navigation systems and air conditioning control panels.

[0058] Smartphone 1 has a display screen 10. Information or images are visually displayed on the display screen 10. The information displayed on the display screen 10 includes, for example, character information, information conveyed through symbols such as graphic symbols, and visual information such as charts. The images displayed on the display screen 10 can be still images or moving images. Images displayed on the display screen 10 include, for example, photographs, illustrations, and maps. For example, the icon 11 displayed on smartphone 1 is both information and an image.

[0059] When displaying the screen 10, the screen 10 brightens; when not displaying, the screen 10 dims. In other words, when displaying the screen 10, first visible light is emitted from the screen 10; when not displaying, no first visible light is emitted from the screen 10. For example, if the screen 10 is a liquid crystal display (LCD), the first visible light is emitted from a backlight. For example, if the screen 10 is an organic EL display (OLED), the light emitted from the OLED is the first visible light. It should be noted that, here, EL is short for electroluminescent display.

[0060] A cover plate 20 is disposed on the display screen 10. Specifically, the display screen 10 is covered by the cover plate 20. The cover plate 20 is transparent or semi-transparent. Therefore, first visible light emitted from the display screen 10 passes through the cover plate 20.

[0061] Figure 2 shows an example of the structure of the cover plate 20. The cover plate 20 includes a substrate film 21, a pattern layer 22, a matte layer 23, and a glossy layer 24.

[0062] The substrate film 21 is transparent or semi-transparent. The substrate film 21 has a first main surface 21a and a second main surface 21b. First visible light emitted from the display screen 10 is incident on the first main surface 21a and exits from the second main surface 21b. That is, the first visible light emitted from the display screen 10 is incident on the first main surface 21a of the substrate film 21, passes through the substrate film 21, and exits from the second main surface 21b. The first visible light is incident and exits in the direction indicated by arrow AR1 in Figure 2, and the second visible light is incident and exits in the direction indicated by arrow AR2.

[0063] A pattern layer 22 is disposed on one side of the first main surface 21a of the substrate film 21. The pattern layer 22 is disposed, for example, on a transparent or translucent molding resin 19, which is one of the constituent elements of the display screen 10. The molding resin 19 is, for example, a resin substrate constituting the display screen 10. The resin used in the molding resin 19 is, for example, polymethyl methacrylate (PMMA) or polycarbonate (PC). A glass substrate may also be used instead of the molding resin 19.

[0064] Pattern layer 22 may have a pattern colored with interference pigments, or a pattern colored with interference pigments and metallic inks. The adhesive resin used to hold the interference pigments in pattern layer 22 is transparent or translucent. The interference pigments in pattern layer 22 are colored by the interference of reflected light from the second visible light incident from the outside of smartphone 1 onto cover plate 20. Therefore, under the first visible light transmitted through pattern layer 22, the interference pigments are not colored, or if they are, the color is very weak. For this reason, when displayed on display screen 10 of smartphone 1, the pattern of pattern layer 22 does not substantially affect the display of display screen 10. In other words, when displayed on display screen 10 of smartphone 1, the operator 100 of smartphone 1 will not recognize the pattern of pattern layer 22, but will recognize the pattern of pattern layer 22 when display screen 10 is not being displayed.

[0065] In the pattern layer 22 with the metallic ink pattern, more incident light incident from the surface of the metallic ink pattern can be reflected, while a portion of the incident light incident from the back can be transmitted. The thickness of the metallic ink is, for example, 0.5 μm to 5 μm. The metallic ink is, for example, an ink in which metal powder is uniformly dispersed in a transparent binder resin. By providing a metallic ink pattern, compared to the case without a metallic ink pattern, more light can be reflected to the surface of the cover plate 20, making the pattern of the pattern layer 22 appear brighter.

[0066] The matte layer 23 is disposed on one side of the second main surface 21b of the substrate film 21. Figure 2 shows an example in which the matte layer 23 is directly disposed on the substrate film 21. However, the matte layer 23 may not be directly disposed on the substrate film 21, or other transparent or translucent layers may be disposed between the matte layer 23 and the substrate film 21.

[0067] The matte layer 23 is a matte layer used for the cover plate 20. The matte layer 23 helps to suppress the reflection of the second visible light in the cover plate 20 and to homogenize the diffusion of the first visible light, thereby improving the visibility of the display screen 10. For this reason, the haze value of the area of ​​the laminate formed by providing the matte layer 23 on the substrate film 21 is larger than that of the substrate film 21 alone. The haze value is measured according to the test method described in JIS-K7136. Since there are other constituent elements in the cover plate 20 besides the substrate film 21 and the matte layer 23, such as the pattern layer 22 and the gloss layer 24, it is considered that it may be difficult to measure the haze value of the portion composed only of the substrate film 21 and the matte layer 23 using the test method described in JIS-K7136. Therefore, the concept of a laminate composed of the substrate film 21 and the matte layer 23 is introduced, such a laminate being, for example, a film on which the matte layer 23 is formed on the entire surface of a substrate film 21. The haze value of the region of the laminate consisting of the substrate film 21 and the matte layer 23 is the haze value after removing other components besides the substrate film 21 and the matte layer 23. In other words, the haze value of such a region of the laminate is obtained, for example, by measuring the haze value of the material of the cover plate 20 on which only the matte layer 23 is formed on the substrate film 21.

[0068] A glossy layer 24 is disposed on the surface 23s of the matte layer 23. The glossy layer 24 is used to form protrusions 24p and recesses 24r in the exposed surface area EX of the cover plate 20. The exposed surface area EX is the portion of the cover plate 20 of the smartphone 1 shown in FIG. 1 outside the edge 2. Here, the exposed surface area EX also extends to the periphery of the display screen 10, but it can also be limited to a portion of the display screen 10. Furthermore, the area where the protrusions 24p and recesses 24r are formed can also be limited to a portion of the display screen 10. By repeatedly forming protrusions 24p and recesses 24r in the exposed surface area EX, the surface roughness of the exposed surface area EX increases. As a result, if an operator's finger touches the exposed surface area EX, the glossy layer 24 transmits a rough tactile sensation of the exposed surface area EX to the finger. It is assumed that the exposed surface area EX of the cover plate 20 without the glossy layer 24 is smoother than the area with the glossy layer 24. For example, for areas of the cover plate 20 that are not exposed, such as the edge 2 of a smartphone 1, since the desired tactile feel is not required, the gloss layer 24 may not be provided, or the gloss layer 24 may be provided but the pattern formed by the protrusions 24p and the recesses 24r may not be formed. In the case where the gloss layer 24 is provided but the pattern formed by the protrusions 24p and the recesses 24r is not formed, for example, the gloss layer 24 below the edge 2 may consist only of the protrusions 24p, only of the recesses 24r, or a matte layer 23.

[0069] The haze value of the cover plate 20 is set to 40% or higher and 85% or lower. However, to ensure good visibility, it is preferable to set the haze value of the cover plate 20 to 60% or higher and 70% or lower. When the haze value of the cover plate 20 is set within the above range, the haze value of the region of the laminate composed of the substrate film 21 and the matte layer 23 is set to 70% or higher and 90% or lower. The haze value of the region of the laminate composed of the substrate film 21, the matte layer 23, and the gloss layer 24 is set to 40% or higher and 65% or lower. When this haze value is achieved, the gloss layer 24 is in a smooth state with no unevenness on the entire surface; in other words, no recesses 24r are formed, and the entire surface is the same as the convex portion 24p. For example, if a sheet with a glossy layer 24 formed on a substrate film 21 and a matte layer 23 prepared as the material of the cover plate 20 is used, the Haze value of the region of the laminate composed of the substrate film 21, the matte layer 23, and the glossy layer 24 can be easily measured. The Haze value is larger when the glossy layer 24 is formed with only recesses 24r than when it is formed with only protrusions 24p. That is, as shown in FIG3, when a glossy layer 24 of uniform thickness is formed on the entire surface, the smaller the tone of the recesses 24r, the larger the Haze value. Taking into account the effect caused by the pattern of the alternating protrusions 24p and recesses 24r, the Haze value of the cover plate 20 is set to be 40% or more and 85% or less.

[0070] Here, the tonal range of the recess 24r will be explained. For example, a large number of dots D1 are printed in the recess 24r. When a portion of the recess 24r is magnified and viewed from above, depending on the type of printing plate used in printing the recess 24r and the raised portion 24p, the numerous dots D1 may sometimes be separated from each other, or sometimes they may be in contact. In this specification, a tonal range of 100% is defined as the case where all dots D1 are connected together and the amount of resin per unit volume is the same as that of the raised portion 24p; a tonal range of 0% is defined as the case where there are no dots D1 at all; and a tonal range of 50% is defined as the density of dots D1 where the amount of resin per unit volume is half that of the raised portion 24p. When the raised portion 24p is also printed in the same manner as the recess 24r, a tonal range of 100% for the dots D1 in the recess 24r means that the entire portion is printed in the same way to maximize the density of dots D1, ultimately resulting in a flush surface where the raised portion 24p and the recess 24r are indistinguishable.

[0071] For example, when the gloss layer 24 is formed by printing, if the recesses 24r and the convexes 24p use dots of the same shape, the convexes 24p are printed with the dot density maximally, while the recesses 24r are printed with the dot density sparser than that of the convexes 24p, thereby forming a surface on the cover plate 20 that gives the convexes 24p and the recesses 24r an alternating tactile feel.

[0072] Since the amount of resin per unit area can be varied between the raised portion 24p and the recessed portion 24r, the raised portion 24p and the recessed portion 24r can also be formed by methods other than dot printing. For example, the recessed portion 24r and the raised portion 24p can also be formed by pressing a printing plate with raised and recessed areas.

[0073] To achieve better visibility, the haze value of the cover plate 20 is preferably set to 50% or higher and 85% or lower. When the haze value of the cover plate 20 is set within the above range, the haze value of the region of the laminate consisting of the substrate film 21 and the matte layer 23 is set to 80% or higher and 90% or lower. The haze value of the region of the laminate consisting of the substrate film 21, the matte layer 23, and the gloss layer 24 is set to 50% or higher and 65% or lower.

[0074] When a raised or recessed area EX is formed on the surface by the gloss layer 24, if the difference in Haze value between the raised portion 24p and the recessed portion 4r of the gloss layer 24 is too large, the visibility will be reduced. However, if the Haze value of the cover plate 20 is too low, the contrast of the raised or recessed pattern will disappear, and the design will be compromised. A range of Haze value between 40% and 85% for the cover plate 20 is a range that can balance design and visibility.

[0075] Preferably, the difference in Haze value between the region of the laminate consisting only of the substrate film 21, the matte layer 23, and the gloss layer 24 and the region of the laminate consisting only of the substrate film 21 and the matte layer 23 is set to be 20% or more and 40% or less. The Haze value of the region of the laminate consisting only of the substrate film 21 and the matte layer 23 is obtained, for example, by measuring the Haze value of a film on the substrate film 21, which is the material used to manufacture the cover plate 20, on which the matte layer 23 is formed. Similarly, the Haze value of the region of the laminate consisting only of the substrate film 21, the matte layer 23, and the gloss layer 24 is obtained, for example, by measuring the Haze value of a film on the substrate film 21, which is the material used to manufacture the cover plate 20, on which both the matte layer 23 and the gloss layer 24 are formed. It should be noted that the regions on the substrate film 21, which is the material for the cover plate 20, on which only the matte layer 23 and the gloss layer 24 are formed, and the regions on the substrate film 21 on which only the matte layer 23 is formed, may sometimes have large, continuous portions of each. In this case, if the film can be used to measure the haze value of each large area, the cover plate 20 can also be used to directly measure the haze value of the region where only the matte layer 23 and the gloss layer 24 are formed on the substrate film 21, and the region where only the matte layer 23 is formed on the substrate film 21. Furthermore, it is even more preferable to set the difference in haze value between the region where only the substrate film 21, the matte layer 23, and the gloss layer 24 are formed and the region where only the substrate film 21 and the matte layer 23 are formed to be 20% or more and 30% or less.

[0076] Due to the patterns depicted by the concave portions 24r and convex portions 24p of the gloss layer 24, the haze value in the exposed surface area EX exhibits positional differences. When the smallest area that can be measured by the haze value measuring instrument is smaller than the area of ​​the exposed surface area EX, it can be determined that the visibility of the area meeting this condition has been improved, provided that the measured haze value of any part of the exposed surface area EX is 40% or more and 85% or less.

[0077] (2) Composition of each part of the cover plate 20

[0078] (2-1) Substrate film 21

[0079] The substrate film 21 may be, for example, a transparent or translucent resin film, a transparent or translucent elastomer film, or a transparent or translucent glass. Among the resin films constituting the substrate film 21, there may be, for example, a thermoplastic resin film composed of a single resin, a thermoplastic resin film mixed with multiple resins, or a film obtained by overlapping multiple layers of thermoplastic resin films. Among the resin films, there may be, for example, a resin film composed of polyester resin, polyethylene terephthalate (PET) resin, acrylic resin, polycarbonate resin, polybutylene terephthalate (PBT) resin, triacetyl cellulose resin, styrene resin, or ABS resin; a multilayer film of acrylic resin and ABS resin; or a multilayer film of acrylic resin and polycarbonate resin.

[0080] The thickness of the substrate film 21 is selected, for example, from a range of 10 μm to 1000 μm.

[0081] (2-2) Pattern layer 22

[0082] The pattern in pattern layer 22 is, for example, a geometric pattern as shown in Figure 4. Pattern layer 22 includes a pattern (here, a geometric pattern) that is visible when the display screen 10 is not lit. The geometric pattern shown in Figure 4 is a grayscale pattern represented by multiple areas separated by straight lines and displayed in different shades. In Figure 4, a geometric pattern is shown as the pattern of pattern layer 22, but the pattern is not limited to geometric patterns. For example, it can also be a natural pattern that imitates the shape or pattern of plants, animals, terrain, etc., existing in nature, such as a wood grain pattern.

[0083] The thickness of the pattern layer 22 is selected, for example, from a range of 1 μm to 50 μm. The pattern layer 22 is formed on the substrate film 21, for example, by screen printing, offset printing, flexographic printing, gravure printing, inkjet printing, or digital printing using toners. The adhesive of the pattern layer 22 is composed of one or more of vinyl chloride vinyl acetate copolymer resin, acrylic resin, thermoplastic polyurethane resin, and polyester resin.

[0084] Figure 7 schematically illustrates an example of the cross-sectional structure of the particles of the interference pigment 22p. The interference pigment 22p, for example, has a core 201 and a thin shell 202 covering the core 201. Both the core 201 and the shell 202 are transparent to visible light. The core 201 and the shell 202 are made of materials with different refractive indices. For example, the refractive index of the core 201 is smaller than that of the shell 202. Arrows AR2 and AR3 represent incident light (second visible light) incident on the shell 202 of the interference pigment 22p. A portion of the incident light, indicated by arrow AR3, propagates within the shell 202 and is reflected by the core 201, becoming the reflected light indicated by arrow AR31. Additionally, a portion of the incident light, indicated by arrow AR2, is reflected by the surface of the shell 202, becoming the reflected light indicated by arrow AR21. The reflected light indicated by arrow AR21 and the reflected light indicated by arrow AR31 interfere with each other and reinforce each other, thus making the interference light of a specific wavelength strongly visually recognizable.

[0085] For example, if the wavelength that enhances interference is made to be the blue wavelength by adjusting the thickness of the shell 202, a blue interference pigment is obtained.

[0086] The first visible light emanating from display screen 10 also enters the interference pigment 22p. The light entering the interference pigment 22p, indicated by arrow AR1 in Figure 7, is the first visible light. The visible light indicated by arrow AR1 enters the interference pigment 22p, passes through it, and exits on the opposite side of the interference pigment 22p. The first visible light passing through the interference pigment 22p is the transmitted light, indicated by arrow AR11. The transmitted light, indicated by arrow AR11, is used to display, for example, icon 11 on display screen 10.

[0087] As shown in Figure 8, if the reflection angles of the incident light IL1 and reflected light RL1 illuminating the interference pigment 22p are different from those of the incident light IL1w and reflected light RL1w, the color of the interference light will change due to the different light paths. Furthermore, if the reflection angles of the incident light IL1 and reflected light RL1 are different from those of the incident light IL1w and reflected light RL1w, the reflectivity will also be different, thus changing the magnitude of the spectral components contained in the interference light. Additionally, if the aforementioned reflection angles are different, the proportion of each frequency spectral component contained in the interference light will also change.

[0088] For example, compared to the reflection angles of incident light IL1 and reflected light RL1, the reflection angles of incident light IL1w and reflected light RL1w are larger, therefore reflected light RL1w is stronger than reflected light RL1. Furthermore, the magnitude of the spectral components contained in reflected light RL1w differs by frequency compared to reflected light RL1, thus resulting in a different hue.

[0089] The pattern layer 22 can also be constructed by stacking multiple layers, including interference pigments 22p that display different colors.

[0090] (2-3) Matte layer 23

[0091] The matte layer 23 can be formed by dispersing transparent microparticles in a transparent resin. Examples of transparent resins include acrylic resins, silicone resins, polyethylene resins, polypropylene resins, polyester resins, polycarbonate resins, epoxy resins, and polyurethane resins. Examples of transparent microparticles include cross-linked acrylic particles, cross-linked styrene particles, talc, glass beads, and silicone particles. The average particle size of the transparent microparticles used to form the matte layer 23 is 2 to 20 μm. For example, the transparent microparticles may include two or more types of particles with a difference of 1.5 μm or more in average particle size.

[0092] In addition to producing diffuse reflection by roughening the surface with transparent microparticles, matte layer 23 can also be configured to produce diffuse reflection by roughening the surface of a transparent or translucent layer without using microparticles.

[0093] (2-4) Gloss layer 24

[0094] As shown in Figure 2, the gloss layer 24 has protrusions 24p and concave portions 24r. The gloss layer 24 has a wavy shape with repeated concave portions 24r and protrusions 24p. The pattern formed by the repetition of concave portions 24r and protrusions 24p is, for example, a geometric pattern as shown in Figure 5. As shown in Figure 6, the pattern formed by such a gloss layer 24 is visually recognized by overlapping with the display of the display screen 10. The pattern formed by the repetition of such concave portions 24r and protrusions 24p can give a prescribed design, but it is also important to prevent the reduction in visibility caused by the repetition of concave portions 24r and protrusions 24p.

[0095] Furthermore, it is important to impart the desired tactile feel to the exposed surface area EX through the repetition of the recesses 24r and convexities 24p of the gloss layer 24. The tactile feel provided by the recesses 24r and convexities 24p of the gloss layer 24 becomes difficult to perceive as the gradation of the recesses 24r approaches 100%. Therefore, it is preferable to set the gradation of the recesses of the gloss layer 24 to 60% or less. To improve visibility, it is preferable to set the gradation of the recesses 24r of the gloss layer 24 to 30% or more to prevent the haze values ​​of the recesses 24r and convexities 24p from becoming too large. For example, in the example shown in FIG3, the gradation of the recesses 24r of the gloss layer 24 is set to 40%.

[0096] For example, when forming the gloss layer 24 by printing, the tonal value of dot D1 in the recess 24r can be adjusted by using halftone dots to adjust the amount of ink during printing the recess 24r. With this printing method, both the recess 24r and the raised portion 24p of the gloss layer 24 can be printed in one operation, saving time. For example, if the amount of ink per unit area for printing the recess 24r is set to half the amount of ink per unit area for printing the raised portion 24p, then the tonal value of dot D1 in the recess 24r is 50% (half).

[0097] The resins used in the gloss layer 24 include, for example, polyvinyl resins, polyamide resins, polyacrylic resins, polyurethane resins, polyvinyl alcohol acetal resins, polyester polyurethane resins, cellulose ester resins, and alkyd resins.

[0098] <Second Implementation Method>

[0099] (3) Overall composition

[0100] In the smartphone 1 and cover plate 20, which are examples of the display devices of the first embodiment described above, the recess 24r and the convex portion 24p are formed by adjusting the tone of the recess 24r of the gloss layer 24. Therefore, both the surface of the recess 24r and the surface of the convex portion 24p are made of the material forming the gloss layer 24.

[0101] As shown in Figure 9, in the cover plate 20 of the second embodiment, the protrusion 24p is formed by a glossy layer 24. However, the glossy layer 24 is not formed in the recess 23r. In other words, by setting the tone of the recess 24r of the glossy layer 24 in the first embodiment to 0%, the cover plate 20 of the second embodiment has a raised / lowered surface in the exposed area EX. That is, the bottom surface of the recess 23r of the cover plate 20 of the second embodiment is formed by the surface of the matte layer 23.

[0102] The substrate film 21 and pattern layer 22 of the cover plate 20 in the second embodiment can be constructed in the same way as the substrate film 21 and pattern layer 22 of the cover plate 20 in the first embodiment.

[0103] In the cover plate 20 of the second embodiment, since the bottom surface of the recess 23r is the surface of the matte layer 23, the haze value of the laminate composed of the substrate film 21 and the matte layer 23 is set to 65% or more and 80% or less. Furthermore, the cover plate 20 is configured such that its haze value is 40% or more and 85% or less. Similar to the first embodiment, to obtain even better visibility, it is further preferable that the cover plate 20's haze value is 60% or more and 70% or less.

[0104] (4) Variations

[0105] (4-1) Variation A

[0106] As shown in FIG10, a cover plate 20 can be formed on a smartphone 1, which serves as a display device, using a decorative sheet 50. The decorative sheet 50 shown in FIG10 includes the same substrate film 21, pattern layer 22, matte layer 23, and gloss layer 24 as in the first embodiment. In forming the cover plate 20, a decorative sheet 50 of the required size is cut from a roll of decorative sheet 50. An adhesive 18 for dry lamination is applied to the pattern layer 22 of the decorative sheet 50. The decorative sheet 50 coated with adhesive 18 is overlapped with a molding resin 19, and pressure is applied. The decorative sheet 50 is bonded to the molding resin 19 using pressure, and as shown in FIG11, the cover plate 20 is formed on the molding resin 19. The molding resin 19 and the cover plate 20 are part of the smartphone 1.

[0107] (4-2) Variation B

[0108] The decorative sheet 50 shown in FIG12 has the same substrate film 21, pattern layer 22, matte layer 23, and gloss layer 24 as in the second embodiment. The cover plate 20 is disposed on the molding resin 19 by overlapping and pressing the decorative sheet 50 coated with adhesive 18 for dry lamination with the molding resin 19, just as in the smartphone 1 shown in FIG11. However, compared to the decorative sheet 50 shown in FIG10, the decorative sheet 50 in FIG12 has a larger step difference in the unevenness formed by the gloss layer 24. Therefore, compared to the decorative sheet 50 shown in FIG12, the decorative sheet 50 shown in FIG10 has a lower risk of residual air bubbles Bu (see FIGS. 13 and 14).

[0109] (4-3) Variation C

[0110] In the first and second embodiments described above, the case of forming a matte layer 23 on the substrate film 21 was explained. However, as shown in FIG15, the substrate film 21A can also be configured to have the function of a matte layer. For example, by using a substrate film 21 doped with transparent microparticles, the substrate film 21 can be given a matte function. That is, the substrate film 21A with a matte function can also be used as a laminate composed of the substrate film 21 and the matte layer 23.

[0111] (4-4) Variation D

[0112] In the first and second embodiments described above, the icon 11 displayed on the display screen 10 of the smartphone 1 was explained. However, even if the techniques described in the first and second embodiments are applied to the case of displaying the icon using a black masking layer patterned in the shape of the icon, it is possible to prevent the icon from being difficult to see due to the unevenness formed by the matte layer 23 and the gloss layer 24. Figures 16 and 17 show an example of displaying the icon using light emitted from the LED 80 toward the matte layer 23 and the gloss layer 24 of the cover plate 20. A patterned portion 25a in the shape of the icon is formed in the masking layer 25 disposed between the LED 80 and the matte layer 23 and the gloss layer 24. By allowing the light from the LED 80 to pass through the patterned portion 25a, the icon is displayed in the exposed area EX on the surface. It should be noted that the difference between the cover plate 20 in Figures 16 and 17 is whether or not a transparent polycarbonate sheet 26 is provided between the masking layer 25 and the molding resin 19. Other transparent sheets may also be used instead of the polycarbonate sheet 26. The shielding layer 25 is formed, for example, by printing with black ink. Alternatively, transparent or translucent glass can be used instead of the transparent or translucent molding resin 19.

[0113] (4-5) Variation E

[0114] In the second embodiment described above, the case in which a matte layer 23 is formed on a substrate film 21 is explained.

[0115] However, the cover plate can also be manufactured using transfer printing. Figure 18 schematically illustrates the manufacturing process of a transfer-based cover plate 20.

[0116] First, matte ink 61 and glossy ink 62 are printed on the prepared carrier film 60, for example, by gravure printing. In the example shown in FIG18, matte ink 61 is printed on the entire surface of the carrier film 60, and glossy ink 62 is printed locally in a manner that overlaps with matte ink 61.

[0117] Next, a transparent resin is applied to form a top layer 63. Then, a pattern layer 64 is printed on the applied top layer 63, for example, by gravure printing.

[0118] The top layer 63 and pattern layer 64 are transferred to the molding resin 19, and the carrier film 60, matte ink 61, and glossy ink 62 do not remain on the cover plate 20. The surface of the top layer 63 included in the cover plate 20 has a surface state in which matte ink 61 is transferred to the convex surface 63x. In addition, the surface of the top layer 63 has a surface state in which glossy ink 62 is transferred to the concave surface 63y.

[0119] As a result, the haze value of the exposed surface area EX formed by the convex surface 63x and the concave surface 63y can be set to 40% or more and 85% or less. Furthermore, the haze value of the convex surface 63x can be set to 65% or more and 80% or less. Additionally, the haze value of the concave surface 63y can be set to 30% or more and 60% or less.

[0120] The resins used in the top layer 63 include, for example, acrylic resin, silicone resin, polyethylene resin, polypropylene resin, polyester resin, polycarbonate resin, epoxy resin, and polyurethane resin.

[0121] (5) Characteristics

[0122] (5-1)

[0123] The cover plate 20 of the smartphone 1, which serves as a display device, or the decorative piece 50 used by the smartphone 1, is disposed on the display screen 10 that emits first visible light to visually display information or images, and is configured in the exposed surface area EX that allows the first visible light emitted from the display screen 10 to pass through.

[0124] The cover plate 20 has a transparent or translucent substrate film 21, a pattern layer 22, a transparent or translucent matte layer 23, and a transparent or translucent gloss layer 24.

[0125] The substrate film 21 has a first main surface 21a and a second main surface 21b. First visible light emitted from the display screen 10 is incident on the first main surface 21a and emitted from the second main surface 21b. A pattern layer 22 is disposed on the first main surface 21a side of the substrate film 21 and has a pattern colored with interference pigment 22p. The interference pigment 22p is colored by interference of reflected light from the second visible light incident from the outside onto the exposed surface area EX. A matte layer 23 is disposed on the second main surface 21b side of the substrate film 21 and is a layer for matting the surface exposed area EX. A gloss layer 24 is disposed on the layer surface 23s of the matte layer 23. The gloss layer 24 is a layer used to form protrusions 24p and recesses 24r in the exposed surface area EX, thereby increasing the surface roughness of the exposed surface area EX compared to the case without the gloss layer 24. It is configured such that the haze value of the exposed surface area EX is 40% or more and 85% or less.

[0126] By setting the haze value of the cover plate 20 or decorative sheet 50, which includes the pattern layer 22 colored with interference pigment 22p, to 40% or more and 85% or less, the gloss layer 24 can impart a tactile feel to the exposed surface area EX caused by the recesses 24r and the protrusions 24p. Furthermore, for displays where the visibility of transmitted light is slightly reduced due to the interference pigment 22p, the boundary between the protrusions 24p and the recesses 24r can be made less obvious, thus improving the visibility of the cover plate 20 or decorative sheet 50.

[0127] (5-2)

[0128] The cover plate 20 shown in Figure 2 or the decorative piece 50 shown in Figure 10 is configured such that the recesses 24r and convexities 24p are formed by a glossy layer 24 having a wavy shape with repeating recesses 24r and convexities 24p. In the cover plate 20 of Figure 2 or the decorative piece 50 of Figure 10, the difference in haze values ​​between the convexities 24p and the recesses 24r can be set by the glossy layer 24, making it easy to set the haze value of the cover plate 20 or the decorative piece 50 to an appropriate value and easily improving visibility. The cover plate 20 of Figure 2 or the decorative piece 50 of Figure 10 can be used, for example, in a smartphone 1, but can also be used in display devices other than smartphone 1.

[0129] (5-3)

[0130] In the cover plate 20 of FIG. 2 or the decorative piece 50 of FIG. 10, the gloss layer 24 is configured, for example, to make the tone of the recess 24r between 30% and 60%. Therefore, the cover plate 20 of FIG. 2 or the decorative piece 50 of FIG. 10 is configured to easily and appropriately set the difference in haze values ​​between the protrusion 24p and the recess 24r, thus easily improving visibility. The cover plate 20 of FIG. 2 or the decorative piece 50 of FIG. 10 is used, for example, in a smartphone 1, but can also be used in display devices other than smartphone 1.

[0131] (5-4)

[0132] In the cover plate 20 shown in Figure 9 or the decorative piece 50 shown in Figure 12, the bottom surface of the recess 23r is formed by the surface of the matte layer 23. In the cover plate 20 of Figure 9 or the decorative piece 50 of Figure 12, the haze value of the bottom surface of the recess 23r can be set to the haze value of the matte layer 23, making it easy to set the haze value of the recess 23r and easily improve visibility.

[0133] (5-5)

[0134] In the cover plate 20 of FIG. 9 or the decorative sheet 50 of FIG. 12, the haze value of the laminate composed of the substrate film 21 and the matte layer 23 is set to 65% or more and 80% or less. Therefore, in the cover plate 20 of FIG. 9 or the decorative sheet 50 of FIG. 12, the blurring of the display image 10 can be suppressed, and the visibility can be significantly improved.

[0135] (5-6)

[0136] The cover plate 20 or decorative piece 50 preferably has a haze value of 60% or higher and 70% or lower. By setting the haze value of the cover plate 20 or decorative piece 50 in this way, it is possible to suppress the obvious boundary between the recesses 24r and 23r and the protrusions 24p, while suppressing the reduction in the contrast of the display screen 10, thus significantly improving visibility.

[0137] Figures 19 to 21 show enlarged views of an icon in a display screen when a glossy layer depicts a geometric pattern. Figure 19 shows an example of a conventional display screen 110. Figure 20 shows a display screen 10 of a smartphone 1 according to the first embodiment. Figure 21 shows a display screen 10 of a smartphone 1 according to the second embodiment. Observing Figure 19, the raised texture caused by the formation of a glossy layer at icon 111 can be seen in the icon, which detracts from the aesthetics. In addition, the boundary of the raised texture of the character 112 below the icon in Figure 19 is not clearly displayed. Comparing Figure 19 with Figures 20 and 21, it can be seen that the boundary of the raised texture caused by the formation of the glossy layer 24 is not easily seen in Figures 20 and 21, and the text is also easy to read. By adopting the configuration of the first embodiment or the second embodiment, the contrast is improved.

[0138] Figures 22 to 24 show enlarged views of an icon in a display screen when the gloss layer depicts a wood grain pattern. Figure 22 shows an example of a conventional display screen. Figure 23 shows a display screen 10 of the smartphone 1 according to the first embodiment. Figure 24 shows a display screen 10 of the smartphone 1 according to the second embodiment. Observing Figure 22, due to the formation of the gloss layer at the icon, the icon and characters become blurred and difficult to visually identify. Furthermore, comparing Figure 22 with Figures 23 and 24, it can be seen that even with the wood grain pattern of the gloss layer 24 in Figures 23 and 24, the blurring of the outlines of the icon and characters is suppressed, and the contrast is improved by adopting the configuration of the first embodiment or the second embodiment.

[0139] Figures 25 to 27 show an enlarged view of an icon when a glossy layer depicts a wood grain pattern and an icon is displayed using a masking layer. Figure 25 shows an example of the patterned portion 125a of the icon on an automotive panel 170 formed by an existing masking layer. Figure 26 shows the patterned portion 25a of the icon on an automotive panel 70 depicting a wood grain pattern of the glossy layer 24 according to the first embodiment (see Figures 16 and 17). Figure 27 shows the patterned portion 25a of the icon on an automotive panel 70 depicting a wood grain pattern of the glossy layer 24 according to the second embodiment (see Figures 16 and 17). Observing Figure 25, due to the formation of the glossy layer, a wood grain pattern appears in and around the patterned portion 125a of the icon, which detracts from the aesthetics of the patterned portion 125a of the icon. However, comparing Figures 25 with Figures 26 and 27, it can be seen that even with the wood grain pattern of the glossy layer 24 present, the patterned portion 25a of the icon and its surroundings are still clear, and the aesthetics are improved by adopting the configuration of the first embodiment or the second embodiment.

[0140] The first and second embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. In particular, the various embodiments and modifications described in this specification can be arbitrarily combined as needed.

[0141] Explanation of reference numerals in the attached figures

[0142] 1. Smartphone

[0143] 10 Display Screen

[0144] 20 Cover plate

[0145] 21 Substrate Film

[0146] 22 Pattern Layers

[0147] 23 Matte layer

[0148] 24 Glossy Layer

[0149] 24p bulge

[0150] 24r, 23r concave part

[0151] 50 decorative pieces

[0152] EX - Exposed area on the surface.

Claims

1. A cover plate disposed on a display screen that emits first visible light to visually display information or images, and disposed on a surface exposed area of ​​a display device through which the first visible light emitted from the display screen passes, the cover plate comprising: a transparent or translucent substrate film having a first main surface and a second main surface, wherein the first visible light emitted from the display screen is incident on the first main surface and the first visible light is emitted from the second main surface; a pattern layer disposed on the first main surface side of the substrate film and having a pattern colored with interference pigment, the interference pigment being colored by interference of reflected light of the second visible light incident from the outside onto the surface exposed area; a transparent or translucent matte layer disposed on the second main surface side of the substrate film for extinction of the surface exposed area; and a transparent or translucent gloss layer disposed on the surface of the matte layer, the gloss layer being a layer for forming protrusions and recesses in the surface exposed area to increase the surface roughness of the surface exposed area compared to the case without the gloss layer, configured such that the haze value of the surface exposed area is 40% or more and 85% or less.

2. The cover plate according to claim 1, wherein, The recess and the convex portion are formed by the glossy layer having a wavy shape that repeats the recess and the convex portion.

3. The cover plate according to claim 2, wherein, The gloss layer is configured such that the tonal range of the dotted portion forming dots in the recess is 30% or more and 60% or less.

4. The cover plate according to claim 3, wherein, The bottom surface of the recess is formed by the surface of the matte layer.

5. The cover plate according to claim 4, wherein, The haze value of the region of the laminate consisting of the substrate film and the matte layer is 65% or more and 80% or less.

6. The cover plate according to any one of claims 1 to 5, wherein, The cover plate is configured such that the haze value of the exposed area of ​​the surface is above 60% and below 70%.

7. A decorative sheet disposed on a display screen that emits first visible light to visually display information or images, and disposed on a surface exposed area of ​​a display device through which the first visible light emitted from the display screen passes, the decorative sheet comprising: a transparent or translucent substrate film having a first main surface and a second main surface, wherein the first visible light emitted from the display screen is incident on the first main surface and the first visible light is emitted from the second main surface; a pattern layer disposed on the first main surface side of the substrate film and having a pattern colored with interference pigment, the interference pigment being colored by interference of reflected light of the second visible light incident from the outside onto the surface exposed area; a transparent or translucent matte layer disposed on the second main surface side of the substrate film for extinction of the surface exposed area; and a transparent or translucent gloss layer disposed on the surface of the matte layer, the gloss layer being a layer for forming protrusions and recesses in the surface exposed area to increase the surface roughness of the surface exposed area compared to the case without the gloss layer, configured such that the haze value corresponding to the portion of the surface exposed area is 40% or more and 85% or less.

8. A display device comprising: a display screen emitting first visible light to visually display information or an image; and a cover plate disposed on an exposed surface area of ​​the display screen and allowing the first visible light emitted from the display screen to pass through, the cover plate comprising: a transparent or translucent substrate film having a first main surface and a second main surface, wherein the first visible light emitted from the display screen is incident on the first main surface and emitted from the second main surface; and a pattern layer disposed on the first main surface side of the substrate film and having a pattern colored with interference pigment, the interference pigment being... Color is achieved by interference of reflected light from a second visible light incident from the outside onto the exposed surface area; a transparent or translucent matte layer is disposed on the second main surface side of the substrate film for extinction of the exposed surface area; and a transparent or translucent gloss layer is disposed on the surface of the matte layer, the gloss layer being a layer used to form protrusions and recesses in the exposed surface area to increase the surface roughness of the exposed surface area compared to the case without the gloss layer, configured such that the Haze value of the exposed surface area of ​​the cover plate is 40% or more and 85% or less.

Images