Indication device

Abstract

The boundary between the display area and the outer edge area, which is visible through the semi-transparent film, is made less visible. [Solution] The display device includes a backlight unit, a liquid crystal display panel positioned in front of the backlight unit, a dimming panel positioned in front of the liquid crystal display panel, and a semi-transparent film positioned in front of the dimming panel. The liquid crystal display panel includes a display area and an outer edge area surrounding the display area. The dimming panel has an opening through which light passes from the display area. The dimming panel overlaps with the outer edge area.

Description

Technical Field

[0006] ,

[0001] The present disclosure relates to a display device.

Background Art

[0002] In the fields of automobiles and home appliances, etc., there is a demand for design and harmony with the surrounding designs in display devices. In order to achieve harmony with the design, a proposal has been made to provide a decorative sheet on the display surface of the display device to impart design. For example, a decorative sheet with a wood grain pattern is known.

[0003] The decorative sheet is a semi-transmissive film that transmits the image light of the display area of the display device to a certain extent. Outside the display portion, the design of the decorative sheet is shown, and in the display portion, the image light is semi-transmitted and displayed, so that both the design and the display can be achieved.

[0004] Normally, when the LCD (Liquid Crystal Display) is not lit, only the film design can be seen throughout through the semi-transmissive film. It is difficult to see the boundary with the LCD because the black color of the LCD and the outer edge area is adjusted to be the same when not lit.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] When displaying an image on an LCD, if a black image is displayed, even if it's black, the brightness of the display area will create a difference in brightness between the outer area and the display area due to the brightness of the backlight, making the boundary easily visible. Therefore, the fact that the LCD is placed behind the semi-transparent film will be visible, and the design and display will not be achieved.

[0007] Furthermore, even when the LCD displays black (0 gradation), the brightness is not zero. Therefore, the backlight light for the LCD on the back of the semi-transparent film passes through, creating a difference in brightness with the surrounding outer edge area, making the boundary easier to see. [Means for solving the problem]

[0008] A display device according to one aspect of the present disclosure includes a backlight unit, a liquid crystal display panel disposed in front of the backlight unit, a dimming panel disposed in front of the liquid crystal display panel, and a semi-transparent film disposed in front of the dimming panel, wherein the liquid crystal display panel includes a display area and an outer edge area surrounding the display area, the dimming panel has an opening through which light passes from the display area, and the dimming panel overlaps with the outer edge area.

[0009] A display device according to one aspect of the present disclosure includes a backlight unit, a liquid crystal display panel disposed in front of the backlight unit, a dimming panel disposed in front of the liquid crystal display panel, a semi-transparent film disposed in front of the dimming panel, and a control device, wherein the liquid crystal display panel includes a display area and an outer edge area surrounding the display area, the dimming panel includes a central area facing the display area and an outer edge area facing the outer edge area, and the control device controls the central area and the outer edge area of ​​the dimming panel, respectively. [Effects of the Invention]

[0010] The boundary between the display area and the outer edge area, which is visible through the semi-transparent film, is made less visible. [Brief explanation of the drawing]

[0011] [Figure 1A] This shows an exploded view of some of the components of a display device. [Figure 1B] Shows a cross-sectional view of the display device. [Figure 2] It is a plan view of the dimming panel. [Figure 3] Shows how the dimming panel can be switched between a transmissive mode and a diffusive mode. [Figure 4] It is a diagram for explaining the brightness on the front surface (decorative surface) of the semi-transmissive film in a display device of related art that does not include the dimming panel. [Figure 5] Explains the comparison between the display device of related art and the display device of an embodiment of the present disclosure regarding the brightness of the decorative surface in LCD black display. [Figure 6] Includes a configuration example of the control device included in the display device of an embodiment of the present disclosure. [Figure 7] Shows a configuration example of the dimming panel of Embodiment 2. [Figure 8] Schematically shows the cross-sectional structure of the display device of Embodiment 2. [Figure 9] It is a diagram for explaining the control of the dimming panel 22 of Embodiment 3. [Figure 10] Shows a configuration example of the display device of Embodiment 4. [Figure 11] Shows the control configuration of the display device of Embodiment 4. [Figure 12] Shows a dimming panel of another configuration example of Embodiment 4.

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments will be specifically described with reference to the drawings. The same reference numerals are given to common configurations in each figure. For the sake of clarity in explanation, the dimensions and shapes of the illustrated objects may be exaggerated in some cases. <Embodiment 1>

[0013] Figures 1A and 1B show a configuration example of a display device 10 according to an embodiment of the present disclosure. FIG. 1A shows an exploded view of some components of the display device 10, and FIG. 1B shows a cross-sectional view of the display device 10. The display device 10 displays an image toward the front side where the user is present. The front side is also called the viewing side. The opposite side of the front side is called the rear side or the back side.

[0014] The display device 10 includes a plurality of components arranged in a stacked manner. Specifically, the display device 10 includes a backlight unit 14 and a liquid crystal display panel (LCD panel) 13 disposed on the front side of the backlight unit. The backlight unit 14 and the LCD panel 13 are included in the liquid crystal display device. The display device 10 includes a dimming panel 12 disposed on the front side of the LCD panel 13 and a transflective film 11 disposed on the front side of the dimming panel 12.

[0015] The transflective film 11 transmits a part of the light from the rear side. The transflective film 11 is, for example, a decorative sheet. FIGS. 1A and 1B show a wood grain decorative sheet as an example of the transflective film 11.

[0016] The LCD panel 13 includes a display area 131 for displaying an image and an outer edge area 132 surrounding the periphery thereof. The outer edge area 132 is a non-display area. The outer edge area 132 blocks the light from the backlight unit 14. The display area 131 includes a plurality of pixels, and an image visible to the user is displayed by controlling the amount of light transmitted through each pixel from the backlight unit 14.

[0017] The dimming panel 12 is disposed between the transflective film 11 and the LCD panel 13. The dimming panel 12 reflects or diffuses external light. The reflection is determined by the degree of diffusion of the dimming panel 12. The dimming panel 12 is, for example, a panel in which liquid crystals such as polymer network liquid crystal (PN-LC) or polymer dispersed liquid crystal (PDLC) are sandwiched between PET films with conductive film layers.

[0018] In the following, the dimming panel 12 is assumed to be a PN-LC dimming panel. When the power to the dimming panel 12 is OFF, the liquid crystals are unevenly aligned, and the light entering the dimming panel 12 is diffused, making it appear opaque. Conversely, when the power to the dimming panel 12 is ON, the liquid crystals align and appear transparent.

[0019] The dimming panel 12 has the same shape as the frame-shaped outer edge region 132. The dimming panel 12 is positioned in front of the LCD panel 13 so as to overlap with the outer edge region 132. Figure 2 is a plan view of the dimming panel 12. The dimming panel 12 has an opening 121 in the center.

[0020] As explained with reference to Figures 1A and 1B, the shape of the aperture 121 coincides with the display area 131, and when superimposed, the display area 131 is exposed at the aperture 121. Therefore, light from the entire display area 131 passes through the aperture 121. In this way, the dimming panel 12 is provided only on the outer edge area 132 and does not overlap with the display area 131. Note that at least the outer periphery of the dimming panel 12 may have a different shape from the outer periphery of the outer edge area 132. The shapes of the display area 131 and the aperture 121 may be rectangular or other shapes.

[0021] As shown in Figure 3, the dimming panel 12 can be switched between a transmissive mode and a diffuse mode. The display device 10 sets the dimming panel 12 to transmissive mode when the backlight unit 14 (LCD display device) is off. The display device 10 sets the dimming panel 12 to diffuse mode when the LCD display device is displaying a completely black area in the display region 131.

[0022] In the display area 131 when displaying black, the dimming panel 12, which overlaps the outer edge area 132, diffuses ambient light, thereby matching the brightness (blackness) of the outer edge area 132 to that of the display area 131. This makes it difficult to see the boundary between the display area 131 and the outer edge area 132 through the semi-transparent film 11 when displaying black.

[0023] Figure 4 illustrates the brightness on the front surface (decorative surface) of the semi-transparent film 11 in a related technology display device 80 that does not include the dimming panel 12. When the LCD display device (backlight unit 14) is turned off, only the film design is visible across the entire surface through the semi-transparent film 11.

[0024] The boundary between the display area 131 and the outer edge area 132 is difficult to see because the colors of the display area 131 and the outer edge area 132 are adjusted so that they are the same black color when the lights are off. The black color matching is done by measuring the reflected light. When the lights are off, only the reflected ambient light 101 is visible.

[0025] On the other hand, when the display area 131 displays black (black display), even though it is black, the brightness of the display area 131 is not zero, so it becomes brighter than the outer edge area 132. The difference in brightness between the display area 131 and the outer edge area 132 makes their boundary more visible. In other words, when the display area 131 displays black (0 gradation), the light 141 from the backlight unit 14 is added to the ambient light 101, making the boundary more visible as a difference in brightness. Therefore, the fact that the LCD panel 13 is located behind the semi-transparent film 11 becomes visible. As a result, the design and display become incompatible.

[0026] Figure 5 illustrates a comparison between a related technology display device 80 and a display device 10 of one embodiment of this disclosure regarding the brightness of the decorative surface in an LCD black display. As explained with reference to Figure 4, in the related technology display device 80, when the display area 131 is displayed in black, the difference in brightness between the display area 131 and the outer edge area 132 makes their boundary more visible.

[0027] In one embodiment of the present disclosure, the display device 10 sets the dimming panel 12 to diffusion mode when the display area 131 is showing black. The degree of diffusion in diffusion mode is adjusted so that the brightness of the display area 131, including the backlight 141, is the same as the brightness of the dimming panel 12 in diffusion mode, which is placed on the outer edge area 132. The degree of diffusion in diffusion mode can be adjusted by the voltage applied to the electrodes. This reduces the brightness difference between the outer edge area 132 and the display area 131, making the boundary between them difficult to see.

[0028] Figure 6 shows an example configuration of a control device 15 included in a display device 10 of one embodiment of the present disclosure. The control device 15 controls the backlight unit 14, the LCD panel 13, and the dimming panel 12 in response to external image data 159 (video frame data).

[0029] The control device 15 includes a dimming panel control unit 152, an LCD panel control unit 153, and a backlight control unit 154. The LCD panel control unit 153 controls the LCD panel 13 according to the image data 159, and the backlight control unit 154 controls the backlight unit 14 according to the image data 159.

[0030] The dimming panel control unit 152 controls the dimming panel 12 in accordance with control signals from the LCD panel control unit 153 and the backlight control unit 154. Specifically, when the backlight unit 14 is turned off, the dimming panel control unit 152 sets the dimming panel 12 to the translucent mode. When the backlight unit 14 is turned on and the LCD panel control unit 153 displays a completely black image in the display area 131, the dimming panel control unit 152 sets the dimming panel 12 to the diffuse mode. The drive voltage in the diffuse mode is preset. <Embodiment 2>

[0031] The dimming panel and its control according to Embodiment 2 will be described below. The differences from Embodiment 1 will be explained primarily below. Unless otherwise specified, the descriptions in Embodiment 1 may apply to this embodiment.

[0032] Figure 7 shows an example of the configuration of the dimming panel 22 of this embodiment. The dimming panel 22 consists of a central region 221 and an outer peripheral region (also called the outer edge region) 222 surrounding the central region. The central region 221 has the same shape as the display region 131, and the outer peripheral region 222 has the same shape as the outer edge region 132. However, the outer periphery of the outer peripheral region 222 may have a different shape from the outer periphery of the outer edge region 132.

[0033] The dimming panel 22 can independently control the mode and diffusion of the central region 221 and the outer region 222. This makes it possible to change the color tone of the design (e.g., wood grain) of the semi-transparent film 11 when displaying black on the LCD.

[0034] Figure 8 schematically shows the cross-sectional structure of the display device 20 of this embodiment. The dimming panel 22 has a constant thickness, and the thickness of the central region 221 and the outer peripheral region 222 are the same. The dimming panel 22 and the LCD panel 13 are stacked on top of each other such that the central region 221 overlaps with the display region 131 of the LCD panel 13, and the outer peripheral region 222 overlaps with the outer edge region 132.

[0035] In the configuration example shown in Figure 8, a transparent adhesive layer 25 exists between the semi-transparent film 11 and the dimming panel 22. The outer shape of the adhesive layer 25 may be the same as or different from the outer shape of the dimming panel 22. The adhesive layer 25 may cover the entire central region 221. The adhesive layer 25 forms an interface with the semi-transparent film 11 and the dimming panel 22, and adheres them together. The adhesive layer 25 can be formed from, for example, optically transparent adhesive (OCR) or optically transparent adhesive sheet (OCA). The adhesive layer 25 may be omitted.

[0036] A transparent adhesive layer 26 exists between the dimming panel 22 and the LCD panel 13. The shape of the adhesive layer 26 may be the same as or different from the shape of the dimming panel 22. The adhesive layer 26 may cover the entire area of ​​the central region 221 and the display region 131. The adhesive layer 26 forms an interface with the dimming panel 22 and the LCD panel 13 and adheres them together. The adhesive layer 26 can be formed from, for example, an optical transparent adhesive or an optical transparent adhesive sheet. The adhesive layer 26 may be omitted.

[0037] The control device 15 drives the central region 221 and the outer region 222 of the dimming panel 22 in accordance with the drive control of the LCD panel 13 and the backlight unit 14. For example, the dimming panel 22 can be controlled as follows. LDC display device: Off: Black display: Black display Central region: Transmission: Transmission: Diffusion: Low Outer region: Transmission: Low diffusion: High diffusion

[0038] In other words, when the LCD display is turned off, the control device 15 sets both the central region 221 and the outer region 222 to a translucent mode. When the LCD display is showing black, the control device 15 controls the central region 221 and the outer region 222 to different states. By setting the central region 221 to a translucent mode and the outer region 222 to a diffuse mode with low diffusion, a darker decorative surface can be presented. Alternatively, by setting the central region 221 to a diffuse mode with low diffusion and the outer region 222 to a diffuse mode with high diffusion, a brighter decorative surface can be presented. In the two different modes of LCD black display, the difference in diffusion between the central region 221 and the outer region 222 can reduce the difference in brightness between the display region 131 and the outer edge region 132.

[0039] As described above, this embodiment makes it possible to change the color tone of the design (e.g., wood grain) of the semi-transparent film 11 while reducing the brightness difference between the outer edge region 132 and the display region 131 by controlling the LCD display state and the degree of diffusion of the central region 221 and the outer peripheral region 222 of the dimming panel 22. <Embodiment 3>

[0040] In this embodiment, in the display device 20 described in Embodiment 2, the central region 221 of the dimming panel 22 facing the display area 131 is controlled in accordance with the display image of the LCD panel 13. Specifically, the control device 15 partially sets the region of the dimming panel 22 corresponding to the dark region within the display area 131 to a translucent mode. This makes the dark region appear even darker. The differences from Embodiment 2 will be mainly described below. Unless otherwise specified, the description in Embodiment 2 may apply to this embodiment.

[0041] Figure 9 illustrates the control of the dimming panel 22 in this embodiment. The LCD display device is operating, and the backlight unit 14 is lit. The LCD panel 13 displays a dark area 135 in the display area 131. The dark area 135 is, for example, a black area. Other areas of the display area 131 are, for example, areas that are brighter than the dark area 135.

[0042] The control device 15 sets the area 225 opposite the dark area 135 in the central area 221 of the dimming panel 22 to a transmit mode (transmitting area) and sets the other areas 224 to a diffuse mode (diffusing area). This control increases the amount of light transmitted and reduces the amount of reflection in the area of ​​the dimming panel 22 opposite the dark area 135 within the display area 131 of the LCD panel 13. As a result, the dark area 135 appears darker, and the contrast of the dark display is increased. <Embodiment 4>

[0043] This embodiment detects ambient light intensity and controls the dimming panel according to the detected ambient light intensity. The differences from Embodiment 1 will be primarily described below. Unless otherwise specified, the descriptions in Embodiment 1 may apply to this embodiment.

[0044] Figure 10 shows an example configuration of the display device 30 of this embodiment. The display device 30 includes a photodetector 17 in addition to the configuration of the display device 10 of Embodiment 1. The photodetector 17 is positioned, for example, near the side surface of the dimming panel 12.

[0045] Figure 11 shows the control configuration of the display device 30. In the control device 15, the dimming panel control unit 152 and the backlight control unit 154 control the dimming panel 12 and the backlight unit 14 in accordance with the detection signal from the photodetector 17. This adjusts the brightness of the backlight unit 14 and the diffusion of the dimming panel 12 according to the ambient light of the user, making the boundary between the display area 131 and the outer edge area 132 less visible.

[0046] Figure 12 shows a dimming panel 32 in another configuration example. The dimming panel 32 includes multiple regions 321-324 that define the aperture 121. In the configuration example shown in Figure 12, the dimming panel 32 is composed of four regions 321-324. The modes and diffusion levels of regions 321-324 can be controlled individually. Note that the number of regions constituting the dimming panel 32 may be different from four.

[0047] Furthermore, photodetectors 171-174 are positioned near regions 321-324, respectively. The control device 15 controls the backlight unit 14 in accordance with the detection signals from the photodetectors 171-174, and also controls the degree of diffusion of each of the dimming panel 321-324 in accordance with the detection signals from the nearby photodetectors 171-174. This makes it possible to more effectively make the boundary between the display region 131 and the outer edge region 132 difficult to see.

[0048] While embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above. Those skilled in the art can easily modify, add to, and transform each element of the above embodiments within the scope of the present disclosure. It is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and to add the configuration of another embodiment to the configuration of one embodiment. [Explanation of Symbols]

[0049] 10, 20, 30 display devices 11 Semi-transparent film 11 12, 22, 32 Dimming Panels 13 LCD panels 14 Backlight Units 15 Control device 17. Photodetector 121 Aperture 131 Display area 132 Outer region 221 Central area 222 Outer area

Claims

1. A display device, Backlight unit and A liquid crystal display panel positioned in front of the backlight unit, A dimming panel positioned in front of the aforementioned liquid crystal display panel, A semi-transparent film placed in front of the dimming panel, Includes, The aforementioned liquid crystal display panel is Display area and, The outer edge region surrounding the aforementioned display area, Includes, The dimming panel has an opening through which light passes from the display area, The dimming panel overlaps with the outer edge region, Display device.

2. A display device, Backlight unit and A liquid crystal display panel positioned in front of the backlight unit, A dimming panel positioned in front of the aforementioned liquid crystal display panel, A semi-transparent film placed in front of the dimming panel, Control device and Includes, The aforementioned liquid crystal display panel is Display area and, The outer edge region surrounding the aforementioned display area, Includes, The aforementioned dimming panel is A central region opposite the aforementioned display region, The outer edge region and c facing it are included, The control device controls the central region and the central region of the dimming panel, respectively. Display device.

Images