Indication device

Abstract

The objective is to provide a display device that allows for the viewing of grayscale images without any unnatural appearance. [Solution] The display device 1 includes a display unit 2 that can take on a grayscale image display state and a grayscale image non-display state, a decorative layer 4 arranged opposite the display unit 2 and coated with a light-transmitting decoration 40, and a surface light-emitting unit 3 arranged between the display unit 2 and the decorative layer 4, which has the function of irradiating light L2 onto the decorative layer 4 and light transmittance through which the grayscale image TI passes. In the grayscale image display state, the grayscale image TI2 is visible from the decorative layer 4 side via the surface light-emitting unit 3, and at the same time, light L2 is irradiated from the surface light-emitting unit 3 toward the decorative layer 4, and the light L2 passes through the decoration 40, thereby suppressing the effect of the decoration that would hinder the visibility of the grayscale image TI2. In the grayscale image non-display state, the irradiation of light L2 from the surface light-emitting unit 3 toward the decorative layer 4 is stopped, making the decoration 40 visible.

Description

[Technical Field]

[0001] This invention relates to a display device. [Background technology]

[0002] Display devices for displaying images have been known for some time. The display device with a panel described in Patent Document 1 (Japanese Patent No. 7307899) comprises a display device with a decorative sheet and a panel member. The display device with a decorative sheet has a display surface for displaying an image and a decorative sheet provided opposite the display surface. When no image is displayed on the display device, the pattern on the decorative sheet can be viewed. When an image is displayed on the display device, the image can be viewed through the decorative sheet. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 7307899 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, if the image is a color or monochrome image that includes relatively low-luminance areas (for example, black areas), the pattern of the decorative sheet will be directly superimposed on those low-luminance areas, which may result in an unnatural appearance depending on the image.

[0005] This invention was made in view of the above problems. This invention makes grayscale images look natural. The objective is to provide a display device that is easily visible. [Means for solving the problem]

[0006] To achieve the above objective, the present invention provides a display device comprising: a display unit having a display area capable of taking between a grayscale image display state in which a grayscale image is displayed and a grayscale image non-display state in which the grayscale image is not displayed; a decorative layer disposed opposite the display area and having a light-transmitting decoration; and a surface light-emitting unit disposed between the display area and the decorative layer and having a surface light-emitting function for irradiating light onto the decorative layer and light transmittance through which the grayscale image is transmitted. In the grayscale image display state, the grayscale image is visible from the decorative layer side through the surface light-emitting unit, and at the same time, light is irradiated toward the decorative layer by the surface light-emitting function, and by transmitting the light through the decoration, the influence of the decoration that hinders the visibility of the grayscale image is suppressed. In the grayscale image non-display state, the irradiation of light toward the decorative layer by the surface light-emitting function is stopped, making the decoration visible. [Effects of the Invention]

[0007] According to the present invention, grayscale images can be viewed without any sense of unnaturalness. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded perspective view of the display device according to the first embodiment. [Figure 2] This figure shows an example of the composition of the decorative layer. [Figure 3] This figure shows an example of the composition of the decorative layer. [Figure 4] This figure shows the viewing status of the display device. [Figure 5] This is a side view of the display device according to the second embodiment. [Figure 6] This is a side view of the display device according to the third embodiment. [Figure 7] This figure shows an example of a display device application. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the configurations described in the following embodiments are merely illustrative, and the scope of the present invention is not limited to the configurations described in each embodiment. For example, each part constituting the present invention can be replaced with any configuration that can perform a similar function. In addition, any configuration may be added. Furthermore, any two or more configurations (features) from each embodiment can be combined.

[0010] <First Embodiment> The first embodiment will be described below with reference to Figures 1 to 3. Figure 1 is an exploded perspective view of the display device according to the first embodiment. Figures 2 and 3 are diagrams showing examples of the configuration of the decorative layer, respectively. Figure 2(a) is a plan view of the decorative layer. Figure 2(b) is a cross-sectional view taken along line AA in Figure 2(a). Figure 3(a) is a plan view of the dots constituting the decoration. Figure 3(b) is a cross-sectional view taken along line BB in Figure 3(a). For the sake of explanation, the upper side in Figures 1, 2(a), and 3(a) will be referred to as "upper (or upward)," and the lower side will be referred to as "lower (or downward)."

[0011] As shown in Figure 1, the display device 1 comprises a display unit 2, a surface light-emitting unit 3, and a decorative layer 4, which are stacked in order from bottom to top. The display unit 2 has a display area 21 on which an image can be viewed. In this embodiment, the image displayed in the display area 21 is a color gradation image TI that includes areas with relatively low brightness (for example, black areas). In the example shown in Figure 1, the gradation image TI is an image that includes a panda P. The gradation image TI may be a moving image or a still image. Furthermore, the display unit 2 is not particularly limited, and for example, a liquid crystal display or an organic EL display can be used. This allows the display unit 2 to display the gradation image TI using each of the RGB color components.

[0012] The display area 21 can take two states. The first state (the first state) is a halftone image display state (hereinafter referred to as the "image display state") for displaying the halftone image TI. The second state (the second state) is a state in which the halftone image TI is not displayed, that is, the halftone image TI is not emitted (irradiated with light) toward the decorative layer 4, and the display area 21 is visually recognized as completely black, which is a halftone image non-display state (hereinafter referred to as the "image non-display state").

[0013] Above the display area 21, a decorative layer 4 is disposed opposite to the display area 21. Note that the decorative layer 4 has a size that includes the entire display area 21 when the display device 1 is viewed from above (in a plan view). The decorative layer 4 is a sheet-like member provided with a decoration 40 having light transmissivity. In this case, the total light transmittance of the decorative layer 4 is preferably 50% or more, more preferably 60% or more and 80% or less. Thereby, even if the intensity of the light L2 irradiated from the surface light-emitting portion 3 to the decorative layer 4 is reduced, the light L2 can pass through the decorative layer 4 (decoration 40), thus contributing to energy saving. Further, the decoration 40 is a wood grain pattern in the present embodiment, but is not limited thereto. For example, it may be a pattern such as black or other single-color painting, metallic or stone grain pattern check pattern, tortoise shell pattern, etc., and further, it may be a decoration having a decorative finish such as high gloss, satin finish, or matte finish on the surface, or other functional processing such as antireflection or scratch prevention, or a combination thereof.

[0014] As a means for applying the decoration 40 having light transmissivity to the decorative layer 4, for example, the method described in Japanese Patent No. 7365576 of forming fine openings in a decoration having no light transmissivity to impart light transmissivity, or the method described in Japanese Patent No. 5725581 of forming a decoration having light transmissivity using a pigment that develops color as interference light on the reflection light side can be mentioned. In the method described in Japanese Patent No. 7365576, if the total light transmittance of the decorative layer 4 is increased, the area of the openings becomes large, and as a result, the decoration 40 may not be clearly visible. Therefore, the method described in Japanese Patent No. 5725581 is more preferable. The method described in Japanese Patent No. 5725581 is specifically shown below.

[0015] As shown in FIGS. 2(a) and 2(b), the decorative layer 4 has a base film 41 and a pattern layer 42 provided on the base film 41 and constituting the decoration 40. The pattern layer 42 has a first-color pattern layer composed of a plurality of first-color dots 423 having red (the first-color dots 423 i-2 ), the first-color dots 423 i-1 ), the first-color dots 423 i ), the first-color dots 423 i+1 ), the first-color dots 423 i+2 ), the first-color dots 423 i+3 ). Further, the pattern layer 42 has a second-color pattern layer provided on the first-color pattern layer and composed of a plurality of second-color dots 422 having green (the second-color dots 422 i-1 ), the second-color dots 422 i ), the second-color dots 422 i+1 ). Furthermore, the pattern layer 42 has a third-color pattern layer provided on the second-color pattern layer and composed of a plurality of third-color dots 421 having blue (the third-color dots 421 i-1 ), the third-color dots 421 i ). The first-color dots 423, the second-color dots 422, and the third-color dots 421 are respectively dots that become "halftone dots" in screen printing.

[0016] As shown in FIGS. 3(a) and 3(b), the first-color dot 423 includes a first-color binder 4232 and first-color pigment chips 4231a, 4231b, 4231c, and 4231d dispersed inside the first-color binder 4232. The first-color pigment chips 4231a to 4231d each have a thin plate that is transparent to light having a wavelength in the visible light region and a metal oxide film that coats the thin plate. The material of the thin plate is not particularly limited, and for example, natural mica, synthetic mica, silica, alumina, glass, poly silicate, etc. can be used. Similar to the first-color dot 423, the second-color dot 422 includes a second-color binder and a plurality of second-color pigment chips dispersed inside the second-color binder. Further, the third-color dot includes a third-color binder and a plurality of third-color pigment chips dispersed inside the third-color binder.

[0017] Thus, the pattern layer 42 includes at least three types of pigment chips. The first-color pigment chip is a red interference pigment that develops color as interference light on the reflection light side. The second-color pigment chip is a green interference pigment that develops color as interference light on the reflection light side. The third-color pigment chip is a blue interference pigment that develops color as interference light on the reflection light side. By containing a red interference pigment, a green interference pigment, and a blue interference pigment, the pattern layer 42 can perform additive color mixing of interference light.

[0018] As shown in FIG. 1, a surface light-emitting portion 3 is disposed between the display region 21 of the display portion 2 and the decorative layer 4. The surface light-emitting portion 3 is configured to be able to irradiate the decorative layer 4 with light L2, which will be described later, by an edge light method. Specifically, the surface light-emitting portion 3 has a light guide plate 31 disposed to face the display region 21 and a light source 32 disposed on the side surface 311 side of the light guide plate 31. Note that the light guide plate 31 has a size that encompasses the entire display region 21 when the display device 1 is viewed from above, similar to the decorative layer 4. Note that the surface light-emitting portion 3 may be a self-light-emitting member such as an organic EL, for example.

[0019] The light source 32 irradiates light L1 toward the side surface 311 of the light guide plate 31. This allows light L1 to be irradiated from a direction that does not interfere with the display area 21. Light L1 from the light source 32 is also incident on the light guide plate 31. This light L1 then exits as light L2 from the upper surface 312 of the light guide plate 31. In the display device 1, the light L2 exiting from the upper surface 312 contributes to the operation in the image display state, as will be described later. The light L2 exiting from the upper surface 312 is directed toward the decorative layer 4. Thus, the light guide plate 31 (surface light emitting section 3) has a surface light emitting function that irradiates light L2 onto the decorative layer 4. The light source 32 is not particularly limited, and for example, an LED can be used. The emission spectrum only needs to include part or all of the visible light wavelength range, and is preferably, for example, 360 nm to 830 nm. The constituent material of the light guide plate 31 is not particularly limited, and for example, an acrylic resin can be used. Furthermore, as mentioned above, the light L2 may be emitted not only from the upper surface 312, but also from the lower surface 313 of the light guide plate 31.

[0020] Furthermore, the light guide plate 31 has light transmittance that allows the grayscale image TI to pass through. Hereinafter, the grayscale image TI that has passed through the light guide plate 31 will be referred to as "grayscale image TI1". The total light transmittance in the thickness direction of the light guide plate 31 is preferably 80% or more, and more preferably 90% or more and 99% or less. In addition, the decorative layer 4, due to its light transmittance, transmits the light L2 irradiated by the surface light emission function and the grayscale image TI1. Hereinafter, the combined component of the light L2 that has passed through the decorative layer 4 and the grayscale image TI1 will be referred to as "grayscale image TI2". Due to this light transmittance, a decrease in the visibility of the grayscale image TI2 in the image display state can be prevented. Furthermore, it is preferable that the average illumination light intensity of the grayscale image TI emitted from the display area 21 of the display unit to the light guide plate 31 is higher than the illumination light intensity of the light L2 directed toward the decorative layer 4 by the surface light emission function, that is, the light L2 emitted from the upper surface 312 of the light guide plate 31 to the decorative layer 4. This makes it possible to increase the contrast ratio of the grayscale image TI2 that is visible after passing through the decorative layer 4. The contrast ratio of the grayscale image TI2 is preferably 1:100 to 1:5000.

[0021] Next, the image display state and the image non-display state will be described. Figure 4 is a diagram showing the viewing state of the display device. Figure 4(a) is a plan view showing the image display state of the display device of the present invention. Figure 4(b) is a plan view showing the image display state of the display device of the comparative example. Figure 4(c) is a plan view showing the image non-display state of the display device of the present invention. Note that the display device 1' of the comparative example has the same configuration as the display device 1 except that the surface light-emitting section 3 is omitted.

[0022] As shown in Figure 4(a), in the image display state of the display device 1, the grayscale image TI is visible as grayscale image TI2 from the decorative layer 4 side. At that time, light L2 is irradiated toward the decorative layer 4 by the surface light emission function. This light L2 passes through the decoration 40 of the decorative layer 4. Due to this transmission, the decoration 40 becomes invisible (cannot be seen with the naked eye), that is, the decoration 40 is made to disappear visually. As a result, the influence of the decoration 40 that hinders the visibility of the grayscale image TI2 can be suppressed, and therefore, the panda P included in the grayscale image TI2 can be seen in its natural colors, that is, in its black and white body color. Also, as mentioned above, the decorative layer 4 and the light guide plate 31 are large enough to encompass the entire display area 21 when the display device 1 is viewed from above. As a result, even if the panda P moves to the right side in Figure 4(a), for example, the panda P can be seen in its natural colors without being affected by the decoration 40.

[0023] As shown in Figure 4(b), in the image display state of the display device 1', the grayscale image TI is visible as the grayscale image TI2' from the decorative layer 4 side. As mentioned above, the display device 1' has a configuration in which the surface light-emitting section 3 is omitted. Therefore, the parts of the panda P with relatively low brightness (for example, parts with a black body color) are visible as the decoration 40 is superimposed on them. In this case, the panda P may appear unnatural (unnatural) to the viewer. In contrast, in the image display state of the display device 1, the grayscale image TI2 (especially the panda P) can be viewed without any sense of unnaturalness.

[0024] As shown in Figure 4(c), when the display device 1 is in the image-display state, the irradiation of light L2 toward the decorative layer 4 by the surface-emitting function of the surface-emitting unit 3 is stopped. As a result, the decorative layer 4 does not transmit light L2 and the grayscale image TI1, and the decoration 40 is visible on the decorative layer 4. In the image-display state of the display device 1', the decoration 40 is visible in the same way as in the image-display state of the display device 1.

[0025] <Second Embodiment> The second embodiment will be described below with reference to Figure 5, focusing on the differences from the previously described embodiment, and similar matters will be omitted from the description. Figure 5 is a side view of the display device according to the second embodiment. For the sake of explanation, the upper side in Figure 5 will be referred to as "upper (or upward)" and the lower side as "lower (or downward)". As shown in Figure 5, in this embodiment, the display unit 2 and the decorative layer 4 have the same size in plan view, while the light guide plate 31 is larger than the display unit 2 and the decorative layer 4. As a result, the light guide plate 31 has a protruding portion 314 that protrudes beyond the display unit 2 and the decorative layer 4. Light L1 is irradiated from the side 311, upper surface 312, and lower surface 313 included in the protruding portion 314. This allows light L1 to be incident on the light guide plate 31 from a direction that does not interfere with the display area 21. Furthermore, the light L2 directed from the light guide plate 31 toward the decorative layer 4 emits light uniformly without any unevenness in intensity across the display area 21.

[0026] <Third Embodiment> The third embodiment will now be described with reference to Figure 6, focusing on the differences from the previously described embodiment, and omitting explanations of similar matters. Figure 6 is a side view of the display device according to the third embodiment. For the sake of explanation, the upper side of Figure 6 will be referred to as "upper (or upward)" and the lower side as "lower (or downward)". As shown in Figure 6, in this embodiment, of the display unit 2, light guide plate 31, and decorative layer 4, the display unit 2 is the smallest in plan view, the decorative layer 4 is the largest, and the light guide plate 31 is of an intermediate size between the display unit 2 and the decorative layer 4. As a result, the light guide plate 31 has a protruding portion 315 that protrudes more than the display unit 2. Light L1 is irradiated from the side surface 311 and the bottom surface 313 included in the protruding portion 315. This allows light L1 to be incident on the light guide plate 31 from a direction that does not interfere with the display area 21. Furthermore, the light L2 directed from the light guide plate 31 toward the decorative layer 4 emits light uniformly without any unevenness in intensity across the display area 21.

[0027] <Examples of application> The following describes application examples of the display devices of the first to third embodiments with reference to Figure 7. Figure 7 is a diagram showing application examples of the display device. For the sake of explanation, the upper side of Figure 7 will be referred to as "upper (or upward)" and the lower side as "lower (or downward)". As shown in Figure 7, the display device 1 is a display device for automobiles (in-vehicle use). Here, as an example, the display device 1 has the function of an instrument that displays speed and the function of displaying a map of a car navigation system. In this way, one display device 1 can have multiple functions. The decorative layer 4 constitutes the outermost layer of the center cluster of the automobile. In addition, the display device 1 can be used not only in automobiles, but also in small saddle-type vehicles such as motorcycles, as well as in railways, ships, aircraft, etc.

[0028] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of its gist. [Explanation of Symbols]

[0029] 1 Display device 2 Display section 21 Display area 3-sided light-emitting section 31 Light guide plate 4. Decorative layer 40 Decorations TI, TI1, TI2 grayscale images

Claims

1. A display unit having a display area capable of switching between a grayscale image display state in which a grayscale image is displayed and a grayscale image non-display state in which the grayscale image is hidden, A decorative layer, which is arranged opposite the display area and has a light-transmitting decoration, The device comprises a surface light-emitting section disposed between the display area and the decorative layer, having a surface light-emitting function that irradiates light onto the decorative layer, and light transmittance that allows the gradation image to pass through. In the aforementioned grayscale image display state, the grayscale image becomes visible from the decorative layer side through the surface light-emitting unit, and at the same time, light is irradiated toward the decorative layer by the surface light-emitting function, and this light passes through the decoration, thereby suppressing the influence of the decoration that would hinder the visibility of the grayscale image. In the state where the grayscale image is not displayed, the illumination of light toward the decorative layer by the surface light emission function is stopped, thereby enabling the decoration to be seen.

2. The display device according to claim 1, wherein the average illumination light intensity of the grayscale image is higher than the illumination light intensity of the light directed toward the decorative layer by the surface light emission function.

3. The surface light-emitting unit includes a light guide plate that directs the light towards the decorative layer when irradiating the decorative layer with light using the surface light-emitting function, and a light source that irradiates the light guide plate with light from a direction that does not interfere with the display area. The display device according to claim 2, wherein the light guide plate is into which light from the light source is incident and which light is emitted onto the decorative layer.

4. The display device according to claim 1, 2, or 3, wherein the decorative layer is composed of a sheet-like member with a total light transmittance of 50% or more.

5. The decorative layer comprises a base film and a pattern layer provided on the base film and constituting the decoration. The display device according to claim 4, wherein the pattern layer includes at least three types of pigment chips, each of the three types of pigment chips being one of a red interference pigment, a green interference pigment, and a blue interference pigment that produce color as interference light on the reflected light side, and the interference light is additively mixed.

6. The display device according to claim 5, which is an in-vehicle display device.

Images