Display device and electronic device

Abstract

A display device is provided with a surface layer which has translucency on the most observer side and has an irregular uneven shape on the observer side. The surface layer has an arithmetic average roughness Ra of 10 [mu] m or more and 3000 [mu] m or less, and a haze value of 40% or more and 85% or less. In the display device, the distance from a point closest to the valley bottom of the uneven shape to an image forming layer on which an image to be displayed is formed is 0.3 mm or less, and on the surface on which the surface layer is laminated, the rate of decrease in brightness in a direction at 60 degrees with respect to the normal direction is 45% or less with respect to the brightness in the normal direction of the surface as a reference. The display device includes: a sensor unit that detects brightness and color of external light incident on a display surface; and an image adjustment unit that adjusts the brightness and color of the image.

Description

Technical Field

[0001] This invention relates to a display device and an electronic machine. Background Technology

[0002] Previously, various display devices, such as liquid crystal displays (LCDs) and organic electroluminescence (EL) displays, were used in various environments and for various purposes. In addition, an image display technology has been proposed and put into practical use to coordinate the usage environment of the display device with the displayed image information, so that the observer can visually recognize the texture of the object displayed as an image.

[0003] For example, as one such technology, as shown in Patent Document 1, a method is known in which multiple fine holes are formed on a sheet printed with a wood grain pattern or the like that harmonizes with the surrounding environment of the display device, and the sheet is arranged on the display surface to project an image from behind the sheet. In this way, as in Patent Document 1, the observer visually recognizes a black screen when no image is displayed, thus suppressing any disharmony with the surrounding environment and thereby enhancing the design.

[0004] In addition, the following method is also known: using sensors to detect the brightness and color of the ambient light around the display device, and adjusting the hue of the image displayed on the display surface based on this information.

[0005] [Previous Technical Documents]

[0006] (Patent Documents)

[0007] Patent Document 1: International Publication No. 2020 / 196906 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] However, in the former method, the image resolution decreases, making it difficult to display vivid images. Furthermore, in either method, when external light is reflected from the display surface, the observer perceives the smooth surface shape of the display, making it difficult to represent the texture of objects. This is especially true when displaying images of objects with finely textured surfaces such as stone, wood, paper, fabric, or oil paintings; a discrepancy arises between the displayed image and the surface shape perceived by the observer, making it difficult to represent texture.

[0010] The present invention was made in view of this problem, and aims to provide a display device or electronic machine that allows the observer to perceive the texture of an image of an object with a finely textured surface, such as wood or stone, paper, oil painting, or fabric, displayed on a display surface, thereby enhancing the design.

[0011] [Technical means to solve the problem]

[0012] (1) A display device displays an image on a display surface and includes: a surface layer that is translucent on the side closest to the observer and has an uneven shape on the observer side; the arithmetic mean roughness Ra of the aforementioned uneven shape is 10 μm or more and 3000 μm or less, the haze value of the aforementioned surface layer is 40% or more and 85% or less, and in the thickness direction of the aforementioned display device, the distance from the point closest to the bottom of the aforementioned uneven shape to the image forming layer forming the image to be displayed is 0.3 mm or less, and on the surface on which the aforementioned surface layer is laminated, the brightness decrease rate in the direction at 60° relative to the normal direction of the aforementioned surface, based on the brightness in the normal direction of the aforementioned surface, is 45% or less. Further, the aforementioned display device includes: a sensor unit that detects the brightness and color of external light incident on the aforementioned display surface; and an image adjustment unit that adjusts the brightness and color of the image displayed by the aforementioned display device based on the information of the brightness and color of the aforementioned external light detected by the aforementioned sensor unit.

[0013] (2) Preferably, the depth of the concave part, the height of the convex part, and the distribution of the concave and convex parts in the surface direction of the aforementioned concave and convex shape are irregular.

[0014] (3) Preferably, the haze value at the outermost surface of the aforementioned concave-convex shape is not uniformly distributed in the surface direction of the aforementioned surface layer.

[0015] (4) Preferably, the positive reflectance of external light incident on the aforementioned display device is less than 1% inside the display device.

[0016] (5) Electronic machine includes the display device of any one of (1) or (4) above.

[0017] (The effect of the invention)

[0018] According to the present invention, a display device or electronic machine can be provided that allows the observer to perceive the texture of an image of an object with a finely textured surface, such as wood or stone, paper, oil painting, or fabric, displayed on the display surface of the display device, thereby enhancing the design. Attached Figure Description

[0019] Figure 1 is a perspective view of the electronic device 1 according to an embodiment.

[0020] Figure 2 is a diagram showing one example of the use of the electronic device 1 according to the embodiment.

[0021] Figure 3 is a diagram illustrating the layer structure of the display device 10 according to the embodiment.

[0022] Figure 4 is a block diagram showing the configuration of the display device 10 according to the embodiment.

[0023] Figure 5 is an enlarged view of a portion of the cross-section of the surface layer 15 of the embodiment.

[0024] Figure 6 is a diagram showing the configuration of the display device for Measurement Example 1.

[0025] Figure 7 is a diagram showing the configuration of the display device for measurement example 2.

[0026] Figure 8 is a graph showing the brightness distribution at the light-emitting surface 12a of the display panel 12 of the display device in Examples 1 and 2.

[0027] Figure 9 is a diagram illustrating the distance S in the display device of an arbitrary measurement example.

[0028] Figure 10 is a table showing the evaluation results of image quality in the display devices of Measurement Examples 3 to 28.

[0029] Figure 11 is a table showing the evaluation results of the image quality of the display devices in Examples 29-38.

[0030] Figure 12 is a photograph of an example of a display device 10 and an electronic device 1, showing a surface layer 15 with an irregular shape, an arithmetic mean roughness Ra, a haze value, and a distance S within a preferred range on a portion of the light-emitting surface 12a.

[0031] Figure 13 is an enlarged view of a portion of a cross-section of the surface layer 35 of another embodiment 1.

[0032] Figure 14 is a photograph showing the condition of the surface of the laminate 40.

[0033] Figure 15 illustrates the layer composition of the laminate 70. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, including Figure 1, the figures shown below are schematic illustrations, and the size and shape of each part are appropriately exaggerated for ease of understanding.

[0035] The dimensions and material names of the components described in this specification are just one example of the implementation method and are not limited thereto. Appropriate options may be selected and used.

[0036] Furthermore, in this specification, terms for specific shapes or geometric conditions, such as parallel or orthogonal, include not only their strict meanings but also states that perform the same optical function and have an error that can be considered parallel or orthogonal.

[0037] (Implementation Method)

[0038] Figure 1 is a perspective view showing the electronic device 1 of this embodiment.

[0039] Figure 2 is a diagram showing one example of the use of the electronic device 1 in this embodiment.

[0040] As shown in Figure 1, the electronic device 1 in this embodiment is a tablet terminal, including a display device 10 having a display surface 10a (screen) for displaying images, a frame 50 for holding the display device 10, an input / output section or communication section (not shown), and a control section (not shown) for controlling the electronic device 1, etc.

[0041] The input section includes input devices such as a mouse, keyboard, touch panel, and buttons, which output the received operation information to the control section of the electronic device 1. The communication section is a module used for communication-related processing. The control section of the electronic device 1 can send and receive information via a network (not shown) through the communication section, for example, it can communicate with an external personal computer such as the electronic device 1.

[0042] Electronic device 1 is not limited to the aforementioned tablet terminal, but may also be a smartphone, e-book reader, digital photo frame, display device for displaying paintings or non-fungible token (NFT) artwork, and electronic textbook, etc. Furthermore, electronic device 1, as an embodiment of the present invention, is not limited to these examples.

[0043] As shown in Figure 2, the electronic device 1 in this embodiment is configured, for example, to be embedded in a wall surface 60 formed of a wooden panel, and the display surface 10a is surrounded by a wooden panel. Therefore, an observer can visually recognize the wood grain pattern of the wood on the wall surface 60 around the display surface 10a.

[0044] In this embodiment, as an example, as shown in Figure 2, an example of an image displaying text or the like on a wood grain pattern is given to illustrate the electronic device 1 and the display device 10. The wood grain pattern of the image is coordinated with the wood grain pattern of the wall surrounding the display device. This display device 10 has the following advantages: for example, it can be used for promotional advertisements or menus in stores, and the displayed text information can be easily changed.

[0045] Furthermore, for the electronic machine 1 and the display device 10 of this embodiment, an example in which the display surface 10a (screen) is rectangular is given for explanation, but the shape of the display surface 10a is not limited to this.

[0046] In conventional display devices or electronic machines, even if images such as text are depicted on the wood grain pattern of wood, the observer will perceive them as flat images displayed on the display surface, making it difficult to coordinate with the surrounding wood of the wall 60.

[0047] In contrast, in the display device 10 and electronic device 1 of this embodiment, when an observer visually recognizes the image displayed on the display surface 10a, the texture of text or the like drawn on the surface of the wood grain pattern can be obtained, and the image display can also be coordinated with the surrounding environment.

[0048] Furthermore, the display device 10 and the electronic device 1 are not limited to the texture of wood grain on the surface of wood. When objects with concave or convex shapes on the surface, such as stone, paper, oil paintings, or fabrics, are displayed on the display surface 10a, the observer can obtain the texture of the object.

[0049] Figure 3 is a diagram illustrating the layer structure of the display device 10 according to this embodiment.

[0050] Figure 4 is a block diagram showing the configuration of the display device 10 according to this embodiment.

[0051] The display device 10 in this embodiment is a transmissive liquid crystal display (LCD) that includes a backlight 11, a display panel 12, a surface layer 15, a display control unit 20, a memory unit 24, and a sensor unit 25.

[0052] In Figure 3 and the following figures, for ease of understanding, the direction parallel to the thickness direction of the display device 10 is appropriately shown as the arrow d direction. In the d direction, the back side of the display device 10 is designated as the -d side, and the observer side is designated as the +d side.

[0053] The display device 10 uses a backlight 11 to illuminate the display panel 12 from the rear side, and displays the image information formed on the display panel 12 on the display surface 10a.

[0054] In general display devices, there is a tendency for the viewing angle to be wider in the horizontal direction and narrower in the vertical direction, depending on the intended use of the display device.

[0055] In contrast, the display device 10 of this embodiment has a uniform and wide viewing angle regardless of the direction within the screen, or a small change in viewing angle, thereby displaying an image with no or minimal change in brightness regardless of the viewing direction.

[0056] The backlight 11 is a surface light source device that illuminates the display panel 12 from the rear side (-d side). In this embodiment, the backlight 11 can be either a side-lit surface light source device including a light guide plate or a direct-lit surface light source device. A general-purpose backlight can be used for the backlight 11.

[0057] As for edge-lit backlights, backlights that appropriately include multiple light-emitting diodes (LEDs) as light sources, a light guide plate and a reflective film to guide light from the light source, a light diffuser to diffuse the light emitted from the light guide plate, a prism to control the direction of light emission, and various optical sheets such as a reflective polarizer to improve the utilization efficiency of specific polarized light are known. Furthermore, as for direct-lit backlights, backlights that appropriately include multiple LEDs arranged as light sources on the back side opposite the light-emitting surface, a reflective film, and various optical sheets such as the light diffuser or prism and the reflective polarizer as described above are known.

[0058] The display panel 12 is a plate-shaped component with a highly transparent glass plate as its substrate, and is a transmissive display unit that displays image information on the display surface 10a of the display device 10. Alternatively, the display panel 12 may also be a film-shaped component with a highly transparent polyimide film as its substrate.

[0059] The display panel 12 in this embodiment is a transmissive liquid crystal panel including an electrode layer (not shown), a polarizing layer, and a liquid crystal layer. Regarding the driving method of the liquid crystal layer of the display panel 12, it is preferable to use a driving method with a wide viewing angle, such as vertical alignment (VA), in-plane switching (IPS), or fringe field switching (FFS).

[0060] In the display device 10 of this embodiment, a surface layer 15 is deposited on the light-emitting surface 12a of the display panel 12. The display device 10 of this embodiment preferably has a relatively flat brightness distribution at the light-emitting surface 12a and wide viewing angle characteristics; when viewed from an oblique angle, the decrease in brightness is smaller, or there is no decrease in brightness, compared to when viewed from the front. Ideally, the display surface 10a of the display device 10 and the electronic device 1 should have a Lambertian distribution with a relatively flat brightness distribution in both the vertical and horizontal directions of the screen.

[0061] The display device 10 of this embodiment preferably has a reduction rate of 45% or less in the brightness (front brightness, brightness at a viewing angle of 0°) of the light-emitting surface 12a in the direction of 60° relative to the normal direction of the light-emitting surface 12a at point B, which is equivalent to point A (refer to Figure 1) which is the center of the display surface 10a.

[0062] The surface layer 15 is deposited on the light-emitting surface 12a of the display panel 12 and is located on the observer side (+d side) of the display device 10. The surface layer 15 can be integrally deposited on the light-emitting surface 12a, or it can be bonded to the light-emitting surface 12a by means of a bonding layer (not shown) with high transparency. In addition, the bonding layer may also have light-diffusing properties.

[0063] The surface layer 15 is a film or sheet-like component that is translucent and has a fine and irregular uneven shape on the observer's side. The surface layer 15 has the function of enhancing the texture of objects in the image displayed on the display surface of the display device 10.

[0064] The surface layer 15 is not limited to the texture of wood as in this embodiment. It can enhance the texture of images of objects with fine and irregular concave and convex shapes on the surface, such as stone, paper, oil paintings, cloth or woven fabrics, etc., by being disposed on the light-emitting surface 12a.

[0065] Figure 5 is an enlarged view of a portion of the cross-section of the surface layer 15 of this embodiment.

[0066] In this embodiment, the surface layer 15 has a substrate layer 151 and an uneven shape layer 152. The surface layer 15 uses its uneven shape to diffuse light emitted from the light-emitting surface 12a of the display panel 12. The diffusion effect is non-directional.

[0067] The substrate layer 151 is a sheet or film-like resin component that is translucent. The resin used to form the substrate layer 151 is preferably a thermoplastic resin such as polycarbonate (PC), methacrylate-butadiene-styrene copolymer (MBS), methacrylate-styrene copolymer (MS), polyethylene terephthalate (PET), polystyrene (PS), or triacetylcellulose (TAC), but is not limited to these, and other resins may also be used.

[0068] The thickness of the substrate layer 151 is preferably 20 to 100 μm, more preferably 30 to 50 μm.

[0069] The uneven shape layer 152 is formed on the observer-side (+d side) surface of the substrate layer 151 in the thickness direction (d direction), and has a fine and irregular uneven shape on the observer-side surface. The uneven shape layer 152 is integrally formed on one side of the substrate layer 151.

[0070] The uneven layer 152 is formed, for example, from a UV-curable resin such as urethane acrylate, polyester acrylate, or epoxy acrylate. Alternatively, the uneven layer 152 may also be formed from other ionizing radiation-curable resins such as electron beam-curable resins.

[0071] The uneven shape of the uneven shape layer 152 is preferably irregular in the distribution of the size (height of the protrusion, depth of the concave) or position of the unevenness, but it can also be an uneven shape with periodicity or the like, depending on the object displaying the image.

[0072] Furthermore, the raised / uneven shape can be formed by coating one side of the substrate layer 151 with a UV-curable resin, pressing a molding die for imparting the raised / uneven shape onto the coating to impart (transfer) the raised / uneven shape, and then irradiating it with UV light to cure the UV-curable resin. Additionally, the method for forming the raised / uneven shape layer 152 is not limited to the above method and can be appropriately selected. Furthermore, regarding the molding die for forming the raised / uneven shape, a mold for forming the raised / uneven shape can also be manufactured based on the surface of the object whose texture is to be enhanced (in this embodiment, the surface of a wooden board) when displayed as an image, thus forming a reverse mold for the raised / uneven shape.

[0073] Furthermore, the surface layer 15 can be configured with a preferred profile shape for the unevenness of the object in the image displayed on the display surface 10a, and the angle of the unevenness or the degree of acuteness of the top of the protrusion can be appropriately set.

[0074] From the viewpoint of improving the texture of objects displayed as images, the arithmetic mean roughness Ra (JIS B 0601:2001) of the uneven shape is preferably 10 μm or more and 3000 μm or less. When the arithmetic mean roughness Ra of the uneven shape is less than 10 μm, the unevenness of the shape is small, the surface of the surface layer 15 is nearly flat, which cannot sufficiently diffuse image light and thus cannot improve texture. Furthermore, when the arithmetic mean roughness Ra of the uneven shape is greater than 3000 μm, the unevenness of the shape is too large, resulting in increased image blurring and thus failing to improve texture. Therefore, the arithmetic mean roughness Ra of the uneven shape is preferably within the above range.

[0075] The arithmetic mean roughness Ra of the convex and concave shape can be measured using a laser microscope (such as the VK-9710 manufactured by Keyence Corporation).

[0076] Furthermore, by satisfying the aforementioned preferred range for the arithmetic mean roughness Ra of the uneven shape, the surface layer 15 can enhance the texture of the object displayed as an image (wood or stone, paper, fabric, painting, etc.). The optimal range for the arithmetic mean roughness Ra varies depending on the object whose texture needs to be improved.

[0077] Furthermore, from the viewpoint of representing texture, the haze value of the surface layer 15 is preferably 40% or higher and 85% or lower. If the haze value of the surface layer 15 is less than 40%, the texture of the object displayed in the image decreases. Furthermore, if the haze value of the surface layer 15 is greater than 85%, the blurriness of the image increases, and the image resolution decreases. Therefore, the haze value of the surface layer 15 is preferably within the above-mentioned range.

[0078] The haze value can be measured according to JIS K 7136:2000 using a haze meter (HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd.). During measurement, parallel light is incident from the surface side of the surface layer 15 (the side of the substrate layer 151) without unevenness or concavity at an incident angle of 0°.

[0079] In addition, the surface layer 15 is not limited to the above example, and may also have the following form.

[0080] The uneven surface layer 152 or the substrate layer 151, or both, may contain particles that serve as a light-diffusing material.

[0081] In addition, the surface layer 15 may also be a single-layer structure without a substrate layer 151.

[0082] Furthermore, the surface layer 15 may also include a reflection-suppressing layer formed along a finely textured surface on its outermost surface. Additionally, the surface layer 15 may include a layer having at least one of the following functions: ultraviolet absorption, antistatic properties, stain prevention, hard coating, etc.

[0083] Furthermore, from the viewpoint of improving the image quality, in the thickness direction (d direction) of the display panel 12, it is preferable that the distance S from the point at the bottom of the valley on the back side of the uneven shape of the surface layer 15 to the surface on the observer side of the image forming layer forming the image in the display panel 12 is 0.3 mm or less.

[0084] As in this embodiment, when the display panel 12 is a liquid crystal display panel, the image forming layer is a liquid crystal layer. Therefore, in this embodiment, the distance S can be adjusted by changing the thickness of the component (i.e., a CF substrate or polarizing layer, etc., not shown) located between the liquid crystal layer and the surface layer 15 of the display panel 12.

[0085] If the distance S is greater than 0.3 mm, the image will be visually perceived as being located on the inner side of the display panel 12, rather than on the outermost surface of the display device 10, which serves as the display surface. This will result in a so-called sense of depth in the image, and the image quality will be reduced. Therefore, the distance S is preferably less than 0.3 mm.

[0086] The display control unit 20, etc., will be explained with reference to Figure 4.

[0087] The sensor unit 25 detects the brightness or color of the light in the operating environment of the electronic device 1 and the display device 10, that is, the brightness or color of the external light incident on the display surface 10a, and outputs it to the image adjustment unit 21. In this embodiment, an example is given in which the sensor unit 25 detects the brightness or color of external light such as sunlight or illumination light incident on point A, which is the center of the screen of the display surface 10a of the display device 10, and outputs it to the image adjustment unit 21 of the display control unit 20.

[0088] The sensor unit 25 may be, for example, a general-purpose spectrophotometer disposed outside the display device 10, or a smaller ambient light sensor that outputs color information (chromaticity) using the tristimulus XYZ color system of the CIE XYZ color system, or a light receiving element disposed within the display panel 12.

[0089] Furthermore, the sensor unit 25 is not limited to the example described above; it can also detect the brightness or color pattern of external light at multiple points on the display surface 10a. In this case, the display surface 10a can be divided into multiple regions, and the sensor unit 25 can detect the brightness or color pattern of external light at a point that is the center of each region. In this case, for example, the display surface 10a can be divided into multiple regions, and a light receiving element for the sensor unit 25 can be arranged within the display panel 12 at the center of each region.

[0090] Furthermore, when a light-receiving element is disposed within the display panel 12 as a sensor unit 25, it can be configured, for example, to be disposed near a pixel electrode in a pixel circuit. In this case, it can be disposed in all pixel circuits in the area that constitutes the display surface 10a, or it can be disposed only in selected locations. As a light-receiving element, a photodiode or the like can be used.

[0091] The display control unit 20 controls the driving of the backlight 11 and the display panel 12, etc. The display control unit 20 includes an image adjustment unit 21, an electrode control unit 22, a light source control unit 23, etc. The display control unit 20 may use a central processing unit (CPU), etc.

[0092] The image adjustment unit 21 adjusts the brightness or hue of the image displayed on the display surface 10a of the display device 10 based on the brightness or color of the external light detected by the sensor unit 25.

[0093] When the sensor unit 25 detects the brightness or color of external light at a location on the display surface 10a, the image adjustment unit 21 adjusts the overall brightness or hue of the image displayed on the screen based on the detected brightness or color information. Furthermore, when the sensor unit 25 detects the brightness or color of external light at multiple points on the display surface 10a, the image adjustment unit 21 can also adjust the brightness or color of the displayed image based on the two-dimensional distribution of the brightness and color of external light on the display surface 10a. In particular, when the sensor unit 25 is arranged at each pixel, the image adjustment unit 21 can also adjust the brightness or color of the image in each pixel area.

[0094] Based on the instructions of the image adjustment unit 21, the electrode control unit 22 controls the voltage on the electrodes of the liquid crystal layer (not shown) of the display panel 12.

[0095] The light source control unit 23 controls the brightness and darkness of the backlight 11 (not shown) by means of the instructions of the image adjustment unit 21.

[0096] The memory unit 24 stores the computer program or data used by the image adjustment unit 21 to adjust the brightness or hue of the image displayed on the display surface 10a. Furthermore, the memory unit 24 temporarily stores data required for processing by the image adjustment unit 21, etc.

[0097] The memory unit 24 may use storage elements such as read-only memory (ROM) or random access memory (RAM).

[0098] The display control unit 20 in this embodiment can input information via the input unit or communication unit of the electronic device 1. Furthermore, not limited to the example described, the display device 10 may also include an input unit or a communication unit.

[0099] The image display performed by the electronic machine 1 and display device 10 according to this embodiment will be described with reference to Figure 4 and the like.

[0100] First, the image to be displayed on the display surface 10a is output to the display control unit 20 via the input or communication unit of the electronic device 1, and the display control unit 20 of the display device 10 is instructed to display the image. For example, in this embodiment, as shown in Figure 2, an image with text drawn on the surface of wood having a wood grain pattern is selected.

[0101] Next, the image adjustment unit 21 sends an instruction to the sensor unit 25 to detect the brightness or darkness of external light. The sensor unit 25 detects the brightness and color of the external light incident on the display surface 10a. In this embodiment, the sensor unit 25 detects the brightness or color of the external light incident on point A, which is the geometric center of the display surface 10a. The sensor unit 25 outputs the detection result to the image adjustment unit 21.

[0102] The image adjustment unit 21 adjusts the brightness or color of the displayed image based on the brightness or color of the external light detected by the sensor unit 25. Specifically, the image adjustment unit 21 retrieves an image processing-related program from the memory unit 24 and calculates the brightness or color of the wood and text under the external light environment detected by the sensor unit 25 based on the program. Then, the image adjustment unit 21 generates an image with adjusted brightness or color (hereinafter referred to as the adjusted image) based on the calculation result.

[0103] Next, based on the adjusted image, the image adjustment unit 21 outputs information required for driving the electrodes of the display panel 12 or driving the light source of the backlight 11 to the electrode control unit 22 of the display panel 12 and the light source control unit 23 of the backlight 11.

[0104] In this way, the display device 10 displays the adjusted image on the display surface 10a.

[0105] At this time, the surface layer 15 of this embodiment has the following effects: as described above, for images of wood or stone, paper, paintings, fabrics, etc. displayed on the screen, the observer can obtain their texture and the texture is enhanced. Furthermore, by means of the sensor unit 25 and the image adjustment unit 21 of the display control unit 20, the display device 10 can display an image that corresponds to the brightness or color of the external light in the environment in which the display device 10 is placed, and the harmony between the image and the surrounding environment can be further improved. As a result, the display device 10 and the electronic device 1 can display images that are harmonious with the surrounding environment and have enhanced texture, and the design can be improved.

[0106] (Evaluation of image quality in the display devices of Examples 1-38)

[0107] Display devices equivalent to the display device 10 of this embodiment or comparative examples, namely Measurement Examples 1 to 38, were prepared, and the texture of the display on the display surface was evaluated. The brightness distribution at the light-emitting surface 12a of the display panel 12 of the display devices of Measurement Examples 1 to 38, the arithmetic mean roughness Ra of the uneven shape of the surface layer 15, the distance S from the bottom of the uneven shape of the surface layer 15 to the liquid crystal layer, which serves as the image forming layer, and the haze value of the surface layer 15 were different.

[0108] (Brightness distribution at the light-emitting surface of the display panel)

[0109] First, display devices for measuring different brightness distributions of emitted light at the light-emitting surface 12a of the display panel 12 are prepared, and the appearance of the image is evaluated.

[0110] The brightness distribution of the emitted light at the light-emitting surface 12a of the display panel 12 is the brightness distribution at point B, which is the center of the light-emitting surface 12a. In the display devices of Measurement Examples 1 and 2, as an example, measurements were taken along the light-emitting surface 12a in the direction corresponding to the left-right direction of the screen in the usage state of the display device (for example, the direction parallel to the long side of the display surface 10a in Figure 2). Viewed from the thickness direction of the display device, point B is the same as point A of the display surface 10a. In addition, for both the display devices of Measurement Examples 1 and 2, the brightness distribution in the direction passing through point B of the light-emitting surface 12a and parallel to the vertical direction of the screen is equal to or differs from the brightness distribution in the direction passing through point B and parallel to the left-right direction of the screen.

[0111] Figure 6 is a diagram showing the configuration of the display device for Measurement Example 1.

[0112] Figure 7 is a diagram showing the configuration of the display device for measurement example 2.

[0113] As shown in Figure 6, the display device of Test Example 1 includes a surface layer 15, a display panel 12, and a backlight 11B. As shown in Figure 7, the display device of Test Example 2 includes a surface layer 15, a display panel 12, and a backlight 11.

[0114] The display devices of Test Example 1 and Test Example 2 differ only in a portion of the optical components constituting the backlight, while the other portions are identical. The display device of Test Example 1 is equivalent to a display device with a surface layer 15 on the outermost surface area layer of a commercially available display device (PV10109LZR40G manufactured by Kingtech Corporation).

[0115] The screen size of the display devices in Test Examples 1 and 2 was 10.1 inches.

[0116] The display panel 12 used in the display devices of Test Examples 1 and 2, from the back side (backlight side) in the thickness direction, includes, in sequence, a polarizing layer 121, a thin film transistor (TFT) substrate 122, a liquid crystal layer 123, a color filter (CF) substrate 124, an optical film (phase refraction film) 125, and a polarizing layer 126. The display panel 12 is an IPS-type liquid crystal display panel.

[0117] The backlight 11B of the display device in Measurement Example 1 includes a light source 111, a light guide plate 112, a reflector 113, a light diffuser 114, a first prism lens 115, and a second prism lens 116.

[0118] The backlight 11 of the display device in Example 2 includes a light source 111, a light guide plate 112, a reflector 113, a light diffuser 114, and a Lambertian light diffuser 117.

[0119] The light source unit 111 is a light-emitting component, and multiple LEDs are arranged at equal intervals along the side surface (light incident surface 112a) of the light guide plate 112.

[0120] The light guide plate 112 is a component that guides the light from the light source 111 to the side 112b opposite to the light incident surface 112a. The reflector plate 113 is a component that reflects the light emitted from the light guide plate 112 toward the back side back to the light guide plate 112 side.

[0121] The light diffuser 114 is an optical component that diffuses and expands the light emitted from the light guide plate 112, and has a non-directional diffusion effect.

[0122] In the backlight 11B of Measurement Example 1, the first prism 115 and the second prism 116 are optical sheets with multiple unit prisms arranged on the observer-side (+d side) surface, which have the function of directing the light emitted through the light diffuser 114 towards the front direction by means of the unit prisms. The unit prisms extend along the sheet surface in one direction, have an isosceles triangular cross-sectional shape, and are arranged in a direction intersecting the length direction.

[0123] When viewed from the thickness direction of the display device, the unit prisms of the first prism 115 and the second prism 116 are arranged in orthogonal directions. In this embodiment, the unit prisms of the first prism 115 are arranged in the vertical direction of the screen, and the unit prisms of the second prism 116 are arranged in the horizontal direction of the screen.

[0124] The Lambertian light diffuser 117 used in the backlight 11 of Measurement Example 2 is an optical sheet that diffuses the incident parallel light before it is emitted, and the brightness distribution of the emitted light is a Lambertian distribution. Here, a diffuser (Zenith Polymer Lambertian diffuser SG3201 manufactured by SphereOptics) is used as the Lambertian light diffuser 117.

[0125] In addition, the brightness distribution of the display device in each test case was measured by displaying a white screen on the display device of each test case and using a conograph manufactured by Autoronic Corporation. The measurement was performed from -80° to 80° along the left and right direction of the screen at point B on the light-emitting surface 12a.

[0126] Figure 8 is a graph showing the brightness distribution at the light-emitting surface 12a of the display panel 12 of the display device in Examples 1 and 2.

[0127] In the graph shown in Figure 8, the vertical axis represents the normalized brightness, and the horizontal axis represents the viewing angle (the angle relative to the normal direction of the screen). In the graph shown in Figure 8, in the display devices of Measurement Examples 1 and 2, the brightness at each viewing angle is normalized with the front brightness as reference 1.

[0128] As shown in Figure 8, in the display device of Measurement Example 1, the brightness decreased as the viewing angle increased, with the half-angle being approximately 25 degrees. In contrast, in the display device of Measurement Example 2, the decrease in brightness was smaller even as the viewing angle increased.

[0129] In the display device of Measurement Example 1, the brightness at a viewing angle of 60° decreased by approximately 83.3% compared to the brightness at a viewing angle of 0° (front brightness). On the other hand, in the display device of Measurement Example 2, the brightness at a viewing angle of 60° decreased by approximately 43.6% compared to the brightness at a viewing angle of 0° (front brightness). The brightness decrease rate is the average of the decrease rate at a viewing angle of +60° and the decrease rate at a viewing angle of -60°.

[0130] In the display devices of the measured examples 1 and 2, with the surface layer 15 disposed on the light-emitting surface 12a of the display panel 12, images of the same wood grain pattern on the same wood surface are actually displayed on the screen, and the texture of its appearance is evaluated.

[0131] The arithmetic mean roughness Ra of the surface layer 15 used in the display devices of Examples 1 and 2 was 100 μm, and the haze value was 60%.

[0132] The display devices in Examples 1 and 2 use a Konica Minolta, Inc. spectroradiometer CL-500A as the sensor unit 25 to measure the brightness or color of external light at point A, which is the center of the display surface 10a. The brightness or color of the image is adjusted by the display control unit 20, and the adjusted image is displayed on the display surface 10a.

[0133] In evaluating the quality of the displayed image, the brightness of the external light incident on point A of the display surface 10a is 100 lx, and the color in the CIE chromaticity diagram has x = 0.303826 and y = 0.329804. This was measured using sensor unit 25 (a Konica Minolta CL-500A spectroradiometer).

[0134] The evaluation of the quality of the displayed image is conducted by an observer in a bright room, observing point A, which is the center of the image, at a 60-degree angle (observation angle of 60 degrees) relative to the normal direction of the display surface 10a from a position 30 cm away.

[0135] The quality of the images displayed on the display surface 10a of the display devices of Examples 1 and 2 is evaluated as follows.

[0136] In the display device of Measurement Example 1, if the viewing angle is large, the brightness of the image decreases significantly, and the brightness changes of the image caused by the viewing angle are drastic. Therefore, in the display device of Measurement Example 1, it is difficult for the observer to obtain the texture of the wood surface from the visually recognized display image.

[0137] On the other hand, in the display device of Measurement Example 2, the changes in brightness of the image caused by the viewing angle are small, allowing the image to be viewed regardless of the viewing angle. Furthermore, the observer can fully perceive the texture of the wood surface from the visually recognized displayed image and identify text drawn on the board.

[0138] Furthermore, in the display device of Test Example 2, when the surface layer 15 was partially removed, the results showed that the portion without the surface layer 15 could be visually identified by reflections of external light, and the flatness of the display surface could be visually identified, but the texture of the wood grain was not easily discernible.

[0139] (Arithmetic mean roughness Ra and distance S of the concave-convex shape)

[0140] Next, display devices with different distances S between the arithmetic mean roughness Ra of the uneven shape of the surface layer 15 and the distance S between the point closest to the bottom of the uneven shape (the point closest to the back side (-d side) of the uneven shape) and the point closest to the observer side (+d side) of the liquid crystal layer 123 are prepared, and the texture of the image displayed on these display surfaces 10a is evaluated.

[0141] The display devices of Measurement Examples 3 to 28 include the same display panel 12 and backlight 11 as those of Measurement Example 2, but the distance S and arithmetic mean roughness Ra are different.

[0142] In the evaluation, the brightness or color of external light at point A on the display surface 10a of each test example's display device is detected by the sensor unit 25, and the image after brightness or color adjustment is displayed by the display control unit 20. Furthermore, the observation position of the displayed image or the conditions of external light for each test example's display device are as described above.

[0143] Figure 9 illustrates the distance S in the display device of an arbitrary measurement example. In Figure 9, a portion of a cross-section of the display device of the arbitrary measurement example, parallel to the thickness direction (d direction), is shown in enlarged form.

[0144] In the display devices of Measurement Examples 3 to 28, as shown in Figure 9, the distance S is the distance from the bottom of the valley on the back side of the uneven shape of the surface layer 15 to the surface of the liquid crystal layer 123 on the observer side. The distance S can be adjusted by changing the thickness of the components between the liquid crystal layer 123 and the surface layer 15, namely the CF substrate 124, the optical sheet 125, and the polarizing layer 126.

[0145] In addition, five examples of surface layer 15 with an arithmetic mean roughness Ra of 5 μm, 8 μm, 10 μm, 3000 μm, and 7000 μm were prepared. Furthermore, six examples of surface layer 15 with a distance S of 0.15 mm, 0.20 mm, 0.25 mm, 0.3 mm, 0.5 mm, and 0.7 mm were prepared.

[0146] Furthermore, in the display devices of the measured examples 3 to 28, the uneven shape layer 152 of the surface layer 15 contains a light-diffusing material (Micropearl manufactured by Sekisui Chemical Co., Ltd., with an average particle size of 10 μm), and the haze value of each surface layer 15 is adjusted to approximately 60% regardless of the arithmetic mean roughness Ra of the uneven shape.

[0147] Figure 10 is a table showing the evaluation results of image quality in the display devices of Measurement Examples 3 to 28.

[0148] In the “Texture Evaluation” table shown in Figure 10, situations where the observer can perceive texture in the visually observed image are considered good and represented by 0, while situations where texture is difficult to perceive are considered poor and represented by ×.

[0149] As shown in the table in Figure 10, the larger the arithmetic mean roughness Ra of the uneven shape, the greater the blurriness of the image, and the less the texture of the object can be obtained. In addition, when the arithmetic mean roughness Ra of the uneven shape of the surface layer 15 is 5 μm or 8 μm, but less than 10 μm, the uneven shape is too small, and the roughness of the surface of the object displayed in the image cannot be visually recognized, so the observer cannot obtain the texture of the image.

[0150] Furthermore, the greater the distance S, the greater the sense of depth of the image (the feeling that the image is displayed further inside the display panel 12 than the display surface, i.e., the depth of the image), and the more difficult it is to obtain the texture of objects.

[0151] For example, when the distance S is 0.3 mm, or even smaller (0.25 mm, 0.20 mm, 0.15 mm), the sense of depth is suppressed and the image texture is obtained when the arithmetic mean roughness Ra of the uneven shape is 10 μm and 3000 μm. However, when the arithmetic mean roughness Ra is 7000 μm, the blurriness of the image increases regardless of the value of the distance S, making it difficult to obtain the image texture.

[0152] Based on the above, by having the arithmetic mean roughness Ra of the uneven shape of the surface layer 15 be 10 μm or more and 3000 μm or less, the texture of objects in the image can be improved. Furthermore, by making the distance S 0.3 mm or less, the sense of depth in the image can be suppressed, thereby improving the texture of objects in the image.

[0153] (Regarding the haze value of surface layer 15)

[0154] Next, display devices with different haze values ​​and arithmetic mean roughness of surface layer 15 and uneven shape were prepared to evaluate the image texture in the same way.

[0155] The display devices in Test Examples 29-38 include the same display panel 12 and backlight 11 as in Test Example 2, but differ in the haze value of the surface layer 15 and the arithmetic mean roughness Ra of the uneven shape. Furthermore, the display devices in Test Examples 29-38 share a common feature: a distance S of 0.25 mm.

[0156] The display devices in Examples 29-33 share a common feature: an arithmetic mean roughness Ra of 10 μm for their uneven shape. However, they differ in their haze values, which are 90%, 85%, 60%, 40%, and 25%, respectively. The display devices in Examples 34-38 share a common feature: an arithmetic mean roughness Ra of 3000 μm. However, they differ in their haze values, which are 90%, 85%, 60%, 40%, and 25%, respectively.

[0157] In the display devices of test examples 29 to 38, the uneven shape layer 152 of the surface layer 15 contains a light-diffusing material (Micropearl manufactured by Sekisui Chemicals Co., Ltd., with an average particle size of 10 μm), and the haze value of the surface layer 15 is adjusted by adjusting its content.

[0158] In the evaluation, the brightness or color of external light at point A on the display surface 10a of each test example's display device is detected by the sensor unit 25, and the image after brightness or color adjustment is displayed by the display control unit 20. Furthermore, the observation position of the displayed image or the conditions of external light for each test example's display device are as described above.

[0159] Figure 11 is a table showing the evaluation results of the image quality of the display devices in Examples 29-38.

[0160] In the "Texture Evaluation" table shown in Figure 11, a situation where the observer can obtain sufficient texture from the visually viewed image is considered excellent and indicated by ◎, while a situation where texture is obtained but is reduced compared to excellent is considered good and indicated by 〇. In addition, the observer's observation position on the display surface 10a and the surrounding ambient light, etc., are considered as described above during the evaluation.

[0161] As shown in the table in Figure 11, it can be seen that the greater the arithmetic mean roughness Ra of the uneven shape of the surface layer 15, the higher the haze value is required to obtain the texture of the object.

[0162] For example, when the arithmetic mean roughness Ra of the uneven shape of surface layer 15 is 3000 μm, if the haze value of surface layer 15 is 40-85%, texture can be obtained for objects in the displayed image, especially when the haze value of surface layer 15 is 85%, a higher texture can be obtained. In contrast, when the arithmetic mean roughness Ra of the uneven shape of surface layer 15 is 10 μm, a high texture can be obtained even with a haze value of 40%.

[0163] When the haze value of surface layer 15 is less than 40%, the image has a greater sense of depth due to its higher transparency. Compared to the case where the haze value of surface layer 15 is 40-85%, the image texture is reduced. Furthermore, when the haze value of surface layer 15 is greater than 85%, the image's sense of depth decreases. Compared to the case where the haze value of surface layer 15 is 40-85%, the image is too blurry, making it easier for the observer to identify as an image, and the texture of the object is reduced.

[0164] Therefore, the haze value of the surface layer 15 is preferably 40% or more and 85% or less.

[0165] Based on the above, in order to enable the observer to perceive the texture of the image displayed on the display surface 10a, a display device 10 and an electronic machine 1 including the display device 10 are preferably provided that meet the following conditions.

[0166] The display device 10 preferably includes: a surface layer 15 having an irregular uneven shape on the observer side (+d side) at the position closest to the observer; the arithmetic mean roughness Ra of the uneven shape is 10 μm or more and 3000 μm or less, the haze value of the surface layer 15 is 40% or more and 85% or less, and the distance S from the point of the bottom of the valley on the back side of the uneven shape to the surface of the image forming layer (liquid crystal layer in this embodiment) closest to the observer side in the thickness direction of the display device 10 is 0.3 mm or less, and the brightness at an observation angle of 60° on the surface where the surface layer 15 is deposited (the light-emitting surface of the display panel 12 in this embodiment) decreases by 45% or less compared to the brightness at an observation angle of 0° (front brightness). Furthermore, the display device 10 preferably includes: a sensor unit 25 for detecting the brightness and color of external light incident on the display surface 10a; and an image adjustment unit 21 for adjusting the brightness and color of the image displayed by the display device 10 based on the information of the brightness and color of the external light detected by the sensor unit 25.

[0167] In this way, the display device 10 can display an image whose brightness and color correspond to the brightness or color of the surrounding external light, and can obtain the texture of the object displayed in the image.

[0168] Figure 12 is a photograph of an embodiment of a display device 10 and an electronic device 1, in which a portion of a surface layer 15 comprising an uneven surface with an arithmetic mean roughness Ra, a haze value, and a distance S within a preferred range.

[0169] The display device 10 and electronic device 1 of the embodiment shown in Figure 12 are the backlight 11 and display panel 12 used in the display device of Measurement Example 2. In Figure 12, a surface layer 15 is shown disposed on a portion of the light-emitting surface 12a. Furthermore, at this time, the brightness or color of the displayed image is adjusted by means of the sensor unit 25 or the image adjustment unit 21, etc. The image displayed on the display surface of the display device 10 of the embodiment is an image of the word "Kepler" written in white-brown paint on a wood grain pattern of brown wood, with the surface layer 15 disposed precisely in the area displaying the text. Furthermore, the photograph shown in Figure 12 was taken under indoor white light illumination (100 lx) at a direction of 60° relative to the normal direction of the light-emitting surface 12a.

[0170] The surface layer 15 shown in Figure 12 has a haze value of 50% and an arithmetic mean roughness of 100 μm for its uneven shape. Furthermore, the display device 10 of the embodiment shown in Figure 12 has a distance S of 0.3 mm, and a brightness reduction rate of 43.65% in the 60° viewing angle direction when the brightness is based on the brightness in the 0° viewing angle direction.

[0171] As shown in Figure 12, in the area where the surface layer 15 is not provided, the observer can visually perceive the smoothness of the light-emitting surface 12a, which serves as the display surface, through reflection of illumination light, and cannot obtain the texture of wood. However, it is observed that the texture of wood is significantly improved in the area where the surface layer 15 is provided, and text is drawn on the wood grain pattern.

[0172] (Other implementation method 1)

[0173] The uneven shape of the surface layer 15 is determined by adjusting the angle of the uneven surface and the distribution of the unevenness according to the uneven shape of the surface of the object whose texture is to be enhanced (wood grain, paper, fabric, stone, etc.), and adjusting the distribution of haze value at the outermost surface of the uneven shape, thereby further enhancing the texture. That is, from the viewpoint of further enhancing the texture, it is preferable to adjust the two-dimensional distribution of haze value according to the uneven shape when viewing the surface layer from above.

[0174] Figure 13 is an enlarged view of a portion of a cross-section of the surface layer 35 of another embodiment 1. In Figure 13, a portion of the cross-section parallel to the thickness direction of the surface layer 35 is shown in enlargement.

[0175] The surface layer 35 of the other embodiment 1 is disposed on the light-emitting surface 12a of the display panel 12 in the same manner as the surface layer 15 of the previous embodiment. The surface layer 35 includes a substrate layer 151 and an uneven shape layer 352. The substrate layer 151 is the same as the substrate layer 151 of the surface layer 15 of the previous embodiment. The uneven shape layer 352 is the same as the uneven shape layer 152 of the previous embodiment, but the distribution of haze values ​​at the outermost surface of its uneven shape is different.

[0176] The distribution of haze values ​​in the planar direction of surface layer 35 is non-uniform. Specifically, the haze values ​​at the outermost surface of the uneven shape of surface layer 35 exhibit a non-uniform secondary distribution in the planar direction of surface layer 35. This non-uniform distribution of haze values ​​follows the irregular unevenness of the shape. Furthermore, on the outermost surface of the uneven shape, the haze value of the protrusions 352a is smaller than that of the recesses 352b. Moreover, the uneven shape of surface layer 35 includes multiple protrusions 352a and recesses 352b, but the haze values ​​at the surface differ for each protrusion 352a and each recess 352b. Therefore, when viewed from above, the haze values ​​of surface layer 35 have a two-dimensional distribution in the planar direction corresponding to the distribution of the uneven shape, and these values ​​are non-uniformly distributed.

[0177] The surface layer 35 of the other embodiment 1 has an uneven shape layer 352 that imitates the shape of wood grain. Furthermore, the haze value at the surface of the protrusion 352a is smaller than the haze value at the surface of the concave portion 352b.

[0178] By configuring the surface layer 35 in this form, when external light such as sunlight or illumination light shines on the surface layer 35, the region of the convex portion 352a, which has a concave-convex shape, has a higher positive reflectivity, while the region of the concave portion 352b has a lower positive reflectivity.

[0179] Therefore, when an observer views the display surface of the display device from the direction of positive reflection of external light, the area corresponding to the convex portion 352a is visually perceived to be brighter than the area corresponding to the concave portion 352b, allowing the observer to more clearly visually distinguish the convex and concave shapes. This provides the observer with a stronger sense of texture for objects displayed on the display surface.

[0180] The haze value at the outermost surface of the uneven shape can be imparted by coating the surface of the uneven shape with resin 354 containing particles 353 with a particle size smaller than the uneven shape. Furthermore, by controlling the amount of particles 353 coated according to the uneven shape, the two-dimensional distribution of the haze value in the surface direction of the surface layer 35 can be controlled.

[0181] As such particle 353, plastic beads are preferred, and examples include styrene beads, melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, etc. Furthermore, both particle 353 and the resin 354 containing it are preferably translucent. Additionally, as the plastic beads used as particle 353, they are preferably those having hydrophobic groups on their surface.

[0182] The refractive index ratio of particle 353 to resin 354 (refractive index of particle 353 / refractive index of resin 354) is preferably 1.0 to 1.1.

[0183] As shown in Figure 13, particle 353 can be in the form of being covered by resin 354, or particle 353 can be in the form of being a part of protruding from the layer of resin 354.

[0184] Furthermore, more than two types of particles can be used for particle 353. For example, when using two types of particles, it is preferable to use particles that differ in one or more of the following: average particle size, shape, material, and refractive index ratio to resin 354.

[0185] In addition, in this configuration, the total haze value of the surface layer 35 is preferably in the range of 40% or more and 85% or less.

[0186] (An evaluation related to the presence or absence of haze values)

[0187] Sample A, an embodiment of surface layer 35 having different haze values ​​for the surface of the protrusion 352a and the surface of the concave 352b, and sample B, an embodiment of surface layer 15 without such haze value difference, are prepared to actually evaluate the texture of the appearance.

[0188] Sample B has an uneven surface, but does not have a haze value distribution corresponding to the uneven surface. Sample A has the same uneven surface as Sample B, and further, a resin 354 containing particles 353 is coated on the outermost surface of the uneven surface. The haze value of the surface of the convex portion 352a of the uneven surface is less than the haze value of the surface of the concave portion 352b.

[0189] Samples A and B both have raised and recessed shapes that mimic wood grain patterns, and they enhance the texture of the wood grain image.

[0190] Texture evaluation is conducted under the following conditions.

[0191] The laminate 40 is fabricated as follows: two linear polarizing plates are laminated on a transparent glass plate with their polarization directions orthogonal, and samples A and B are then placed adjacent to each other on top of the laminate. The laminate 40 is illuminated with external light, and an observer observes and evaluates the texture of the areas where samples A and B are located. When illuminated, the illuminance at the center of the surface of the laminate 40 is 100 lx.

[0192] Figure 14 is a photograph showing the condition of the surface of the laminate 40. In Figure 14, the illumination light, which is the main external light, is incident on the surface of the laminate 40 at an incident angle of 40 degrees. Figure 14 shows the condition as viewed from the positive reflection direction of the illumination light.

[0193] In region 403, where there are two linear polarizing plates in the glass plate stack and no surface layer is provided, two polarizing plates are orthogonally arranged, so it appears black, but as shown in Figure 14, it appears whitish due to the reflection of the illumination light.

[0194] In the embodiment of sample B, where two linear polarizing plates are laminated in a glass plate and a surface layer 15 is provided, the reflection of illumination light is suppressed in region 402, resulting in a visually darker appearance compared to region 403 where no surface layer is provided. Furthermore, in region 402 where sample B is provided, a wood grain pattern achieved using an embossed shape is visually discernible, providing a wood grain texture. However, a portion of the external light is orthogonally reflected on the embossed surface in the same manner, making it slightly brighter than region 401 described below.

[0195] In contrast, in region 401 of sample A, which has two linear polarizing plates laminated in a glass plate and is provided with a surface layer 35, the matte texture reminiscent of wood is further enhanced by the light diffusion effect of particles 353 disposed on the outermost surface of the uneven shape. Furthermore, in region 401, the convex portions 352a are visually brighter, the concave portions 352b are darker, and the variation in brightness along the wood grain pattern is visually apparent, resulting in a higher degree of reproduction of the wood grain texture. Therefore, region A, where sample A is disposed, exhibits a higher wood grain texture compared to region 402, where sample B is disposed.

[0196] Based on the above, it is preferable that the haze value at the outermost surface of the uneven shape of the surface layer 35 is not uniformly distributed in the surface direction of the surface layer 35. Furthermore, it is preferable that the haze value of the convex portion 352a is smaller than the haze value of the concave portion 352b on the outermost surface of the uneven shape of the surface layer 35.

[0197] (Other implementation method 2)

[0198] Furthermore, in a liquid crystal display device like the display device 10 of this embodiment, if external light is incident on the display panel 12 used for image display, not only the outermost surface of the display panel 12 but also a portion of the external light is reflected inside the display panel 12. Moreover, if the reflected light reaches an observer, it will be perceived as glare, and the texture of the object displayed on the display surface 10a will be reduced. Therefore, it is ideal that the reflectivity of external light inside the display device 10, and especially the orthogonal reflectivity of external light inside the display panel 12 in the display device 10 of this embodiment, is 1% or less.

[0199] As an example, this display panel 12 can be implemented by using a circular polarizer on the observer side of the liquid crystal layer instead of the previous polarizer disposed on the observer side of the liquid crystal layer.

[0200] By using the display device described in the other embodiment 2 as above, an observer who is viewing an image of an object displayed on the display surface can obtain a stronger sense of the object's texture.

[0201] (An evaluation related to the reflectivity of external light inside the display device)

[0202] Prepare the following laminate 70, and evaluate the texture enhancement effect of the surface layer by the reflectivity of external light inside the display device.

[0203] Figure 15 illustrates the layer composition of the laminate 70. For ease of understanding, illustrations of the diffusion and refraction of external light L are omitted from Figure 15.

[0204] The laminate 70 is formed by laminating two linear polarizing plates 72 and 73 on a mirror 71, and then further mounting a surface layer 15 on top of them. The surface layer 15 has a textured shape suitable for reproducing wood grain patterns and enhances the texture of the wood grain patterns. In addition, the cross angle of the polarization directions of the two linear polarizing plates 72 and 73 can be adjusted, thereby adjusting the positive reflectivity of external light within the laminate 70.

[0205] The external light L (illumination light) is incident at an angle of 60 degrees relative to the surface direction of the surface layer 15 of the laminate 70. The illuminance at the center of the surface layer 15 is 100 lx.

[0206] Regarding the positive reflectance of external light, a spectroradiometer (SR-UL1 manufactured by TOPCON TECHNOHOUSE) was used with the surface layer 15 removed from the self-assembled body 70. Specifically, the measurement light was incident on the surface of the linear polarizer 73 at an incident angle of 5 degrees, and the reflected light with a reflection angle of 5 degrees was measured by the spectroradiometer to calculate the positive reflectance. In addition, an observer observed and evaluated the texture from a direction 60 degrees away from the normal direction relative to the surface direction of the surface layer 15.

[0207] When the positive reflectance of external light in the laminate 70 is 1%, the light reflected by the mirror 71 is reduced, and the texture of the wood grain pattern on the surface layer 15 cannot be fully obtained.

[0208] When the positive reflectance in the laminate 70 is 1.5%, the light reflected by the mirror 71 can be visually recognized, and the texture of the wood grain pattern on the surface layer 15 can be obtained, but it is lower than when the positive reflectance is 1%.

[0209] When the positive reflectance in the laminate 70 is 2%, the light reflected by the mirror 71 is visually very strong, making it impossible to obtain the texture of the wood grain pattern on the surface layer 15.

[0210] Based on the above, it is ideal that the reflectivity of external light inside the display device 10, and especially the positive reflectivity of external light inside the display panel 12 in the display device 10 of this embodiment, is 1% or less.

[0211] (Deformed form)

[0212] The invention is not limited to the embodiments described above, and various modifications or alterations can be made, which are also within the scope of the invention.

[0213] (1) As a display device 10, an example of a liquid crystal display device is given, but it is not limited to this, and it may also be a plasma display or an organic EL display, etc.

[0214] When it is a plasma display, the distance S is the distance from the point at the bottom of the valley of the uneven shape of the surface layer 15 to the observer-side surface of the phosphor inside the display. Furthermore, when it is an organic EL display, the distance S is the distance from the point at the bottom of the valley of the uneven shape of the surface layer 15 to the observer-side surface of the organic EL material layer inside the display.

[0215] Furthermore, when it is a plasma display or an organic EL display, it is also preferable that the positive reflectance of external light inside the display device is 1% or less.

[0216] (2) The display device 10 may also be configured in the dashboard of a car, the interior equipment of a vehicle or ship, etc.

[0217] The following notes further disclose the above-described embodiments and variations.

[0218] (Note 1)

[0219] A display device for displaying an image on a display surface, the display device comprising: a surface layer having light transmittance on the side closest to the observer and having an uneven shape on the observer side, wherein the arithmetic mean roughness Ra of the uneven shape is 10 μm or more and 3000 μm or less, the haze value of the surface layer is 40% or more and 85% or less, and in the thickness direction of the display device, the distance from the point closest to the bottom of the uneven shape to the image forming layer forming the image to be displayed is 0.3 mm or less, and on the surface on which the surface layer is laminated, the brightness decrease rate in a direction at 60° relative to the normal direction of the surface, based on the brightness in the normal direction of the surface, is 45% or less.

[0220] (Note 2)

[0221] The display device as described in Appendix 1 includes: a sensor unit that detects the brightness and color of external light incident on the aforementioned display surface; and an image adjustment unit that adjusts the brightness and color of the displayed image based on the information of the brightness and color of the aforementioned external light detected by the aforementioned sensor unit.

[0222] (Note 3)

[0223] The display device as described in Appendix 1 or 2, wherein the depth of the concave portion, the height of the convex portion, and the distribution of the concave and convex portions in the surface direction of the aforementioned concave-convex shape are irregular.

[0224] (Note 4)

[0225] The display device as described in any one of Appendices 1 to 3, wherein the haze value at the outermost surface of the aforementioned uneven shape is not uniformly distributed in the planar direction of the aforementioned surface layer.

[0226] (Note 5)

[0227] The display device as described in any one of Appendices 1 to 4, wherein the external light incident on the aforementioned display device has a positive reflectance of less than 1% inside the display device.

[0228] (Note 6)

[0229] An electronic machine, including a display device according to any one of notes 1 to 5.

[0230] Furthermore, this embodiment and its variations can be used in combination as appropriate, and detailed descriptions are omitted. Moreover, this invention is not limited to the embodiments described above.

[0231] Figure Labels

[0232] 1: Electronic machines

[0233] 10: Display device

[0234] 10a: Display surface

[0235] 11: Backlight

[0236] 11B: Backlight

[0237] 12: Display Panel

[0238] 12a: Light-emitting surface

[0239] 15,35: Surface layer

[0240] 20: Display Control Unit

[0241] 21: Image Adjustment Unit

[0242] 22: Electrode Control Unit

[0243] 23: Light Source Control Department

[0244] 24: Memory Department

[0245] 25: Sensor Section

[0246] 40,70: Laminated bodies

[0247] 50: Frame section

[0248] 60: Wall

[0249] 71: Mirror

[0250] 72, 73: Linear polarizing plate

[0251] 111: Light Source Department

[0252] 112: Light guide plate

[0253] 112a: Incident surface

[0254] 112b: Side view

[0255] 113: Reflector

[0256] 114: Light diffusion sheet

[0257] 115: First Prism Lens

[0258] 116: Second prism lens

[0259] 117: Lambertian diffuser plate

[0260] 121: Polarizing layer

[0261] 122:TFT substrate

[0262] 123: Liquid Crystal Layer

[0263] 124:CF substrate

[0264] 125: Optical film (phase reversal film)

[0265] 126: Polarizing layer

[0266] 151: Substrate layer

[0267] 152: Uneven Shape Layer

[0268] 352: Uneven Shape Layer

[0269] 352a:convex part

[0270] 352b: concave part

[0271] 353: Particle

[0272] 354: Resin

[0273] 401, 402, 403: Areas

[0274] Points A and B

[0275] d: direction

[0276] +d: Observer side

[0277] -d: Back side

[0278] L: External light

[0279] S: Distance

Claims

1. A display device for displaying images on a display surface, The aforementioned display device includes: The surface layer is translucent on the side closest to the observer and has an uneven shape on the observer's side; The arithmetic mean roughness Ra of the aforementioned uneven shape is greater than 10 μm and less than 3000 μm. The haze value of the aforementioned surface layer is above 40% and below 85%. In the thickness direction of the aforementioned display device, the distance from the lowest point of the aforementioned uneven shape to the image forming layer forming the image to be displayed is less than 0.3 mm. On a surface with the aforementioned surface layer, taking the brightness in the normal direction of the aforementioned surface as a reference, the rate of decrease in brightness in a direction at 60° relative to the normal direction of the aforementioned surface is 45% or less. The aforementioned display device further includes: a sensor unit for detecting the brightness and color of external light incident on the aforementioned display surface; and, The image adjustment unit adjusts the brightness and color of the image displayed by the display device based on the brightness and color information of the external light detected by the aforementioned sensor unit.

2. The display device according to claim 1, wherein, The depth of the concave portion, the height of the convex portion, and the irregular distribution of the concave and convex portions in the surface direction of the aforementioned concave-convex shape are all irregular.

3. The display device according to claim 1, wherein, The haze value at the outermost surface of the aforementioned uneven shape is not uniformly distributed in the surface direction of the aforementioned surface layer.

4. The display device according to claim 1, wherein, The external light incident on the aforementioned display device has an orthophoto rate of less than 1% inside the display device.

5. An electronic machine comprising the display device according to any one of claims 1 to 4.

Images