Display device

Abstract

To provide a display device that enables even a user wearing polarized sunglasses to satisfactorily view content required to be displayed by law.SOLUTION: The display apparatus 100 emits display light L toward a ceramic formation part 3a provided in a lower end region of the windshield 3. The display device 100 includes a liquid crystal panel 10 and a phase difference part 30 provided to cover a part of a display region of the liquid crystal panel 10. The phase difference part 30 is provided so as to cover a specific region of the display region, the specific region displaying content required to be displayed by law. In the display light L, when light traveling from the display area toward the ceramic formation part 3a without passing through the retardation part 30 is defined as first light L1 and light traveling from the specific area toward the ceramic formation part 3a through the retardation part 30 is defined as second light L2, the second light L2 has a higher ratio of P-polarized light components than the first light L1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] For example, Patent Document 1 describes a display device that emits display light that displays an image toward a ceramic formation portion (colored portion) provided in the lower end region of a vehicle windshield. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4949133 Summary of the Invention [Problem to be solved by the invention]

[0004] This type of display device is generally configured to have more S-polarized components than P-polarized components in order to increase the reflectivity of the display light on the windshield. However, if a user (usually a vehicle driver) wears polarized sunglasses, the polarized sunglasses are designed to block the S-polarized components, significantly reducing the display brightness when the user views an image. This can make it difficult for the user to view content that is required by law to be displayed within the displayed image.

[0005] The present disclosure has been made in consideration of the above-described situation, and aims to provide a display device that allows users wearing polarized sunglasses to clearly see content that is required to be displayed by law. [Means for solving the problem]

[0006] In order to achieve the above object, the display device according to the present disclosure comprises: A display device that emits display light that displays an image toward a ceramic forming portion provided in a lower end region of a vehicle windshield, a liquid crystal panel having a display area illuminated by a backlight unit to display the image; a retardation unit provided to cover a part of the display area, The display area includes a specific area for displaying content required by law, the phase difference portion is provided to cover the specific region, Of the display light, light traveling from the display area toward the ceramic forming portion without passing through the retardation portion is defined as first light, and light traveling from the specific area toward the ceramic forming portion through the retardation portion is defined as second light. The second light has a higher ratio of P-polarized light components than the first light. [Effects of the Invention]

[0007] According to the present disclosure, even a user wearing polarized sunglasses can clearly see content that is required to be displayed by law. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a state in which a display device according to an embodiment of the present disclosure is mounted on a vehicle; [Figure 2] FIG. 2 is a plan view of the liquid crystal panel according to the embodiment, showing a display area. [Figure 3] FIG. 2 is a partial plan view of the backlight unit according to the embodiment. [Figure 4] 3 is a schematic cross-sectional view of the retardation portion, the liquid crystal panel, and the circuit board according to the embodiment taken along line II in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described with reference to the drawings.

[0010] As shown in FIG. 1, the display device 100 according to this embodiment is mounted on a dashboard 2 (including an instrument panel) of a vehicle 1, and emits light (hereinafter, display light L) that displays an image toward a ceramic-formed portion 3a provided in the lower end region of a windshield 3 (windshield) of the vehicle 1. The display light L emitted from the display device 100 passes through a cylindrical body 2a that constitutes part of the dashboard 2 and reaches the ceramic-formed portion 3a. FIG. 1 is a diagram showing a manner in which the display device 100 is mounted on a vehicle 1. Note that in the figure, directions of the vehicle 1 are indicated as forward Fd, backward Bd, upward Ud, and downward Dd. Unless otherwise specified, the directions of forward, backward, upward, and downward used in the following description follow the directions shown in the figure.

[0011] The ceramic-formed portion 3a is a portion of the windshield 3 where black ceramic is formed by baking coating, and is commonly called a black ceramic portion. A reflective surface that reflects the display light L toward the user 4 is formed on the inner surface of the ceramic-formed portion 3a of the windshield 3. The display light L includes S-polarized light and P-polarized light with respect to the reflective surface, as described below. The user 4 is, for example, the driver of the vehicle 1.

[0012] The ceramic forming portion 3a may be provided on the inner surface (the surface facing the user 4) of the windshield 3, or on the outer surface of the windshield 3. Furthermore, when the windshield 3 is made of a laminated glass of multiple sheets of glass, the ceramic forming portion 3a may be provided inside the windshield 3.

[0013] The display light L reflected by the ceramic forming portion 3a travels toward the user 4. By placing the user 4's viewpoint within the eye box 5, the user 4 can visually recognize a virtual image of the image represented by the display light L. To the user 4, the image appears to be displayed on the ceramic forming portion 3a. The image shows, for example, various pieces of information about the vehicle 1 (hereinafter referred to as vehicle information). The vehicle information may include not only information about the vehicle 1 itself, but also external information about the vehicle 1, such as information about the surroundings of the vehicle 1.

[0014] The display device 100 includes a liquid crystal panel 10, a backlight unit 20, a retardation section 30, a housing 40, and a heat dissipation section 50.

[0015] The liquid crystal panel 10 is, for example, a TFT (Thin Film Transistor) type, and has a display area 10a (see FIG. 2) that is illuminated by a backlight unit 20 and displays an image.

[0016] The display area 10a includes a first meter area M1 and a second meter area M2 in which images simulating pointer-type instruments are displayed. A speedometer image is displayed in the first meter area M1. A tachometer image is displayed in the second meter area M2. The first meter area M1 also includes a specific area R1 that digitally displays vehicle speed. In addition, the display area 10a also includes a specific area R2 that displays a fuel gauge image, a specific area R3 that displays a shift position image, and a specific area R4 that displays a warning image including a seat belt reminder. The specific areas R1 to R4 are examples of areas that display content that is required by law to be displayed when the vehicle 1 is traveling.

[0017] As shown in FIG. 3, the backlight unit 20 includes a circuit board 21 and a reflector 22.

[0018] The circuit board 21 is a PCB (Printed Circuit Board). A plurality of light sources 21a are mounted on the circuit board 21 and are arranged in the vertical and horizontal directions when the circuit board 21 is viewed from above. For example, the light sources 21a are LEDs (Light-Emitting Diodes). Although not shown, a driver IC (Integrated Circuit) for driving the plurality of light sources 21a is mounted on the underside of the circuit board 21.

[0019] The light emission of the multiple light sources 21a is controlled by local dimming via a driver IC under the control of a control unit (not shown). That is, the brightness of the light sources 21a is controlled for each dimming zone, which is defined as described below. In this embodiment, one light source 21a is provided for each dimming zone. The control unit (not shown) is electrically connected to each of the liquid crystal panel 10 and the circuit board 21, and is configured with a microcontroller that controls the operation of the liquid crystal panel 10 and the multiple light sources 21a.

[0020] The reflector 22 surrounds each of the plurality of light sources 21a and defines dimming zones, the number of which corresponds to the number of the plurality of light sources 21a. The reflector 22 is formed, for example, from a white resin. An enclosing portion of the reflector 22 that surrounds one light source 21a corresponds to one dimming zone. The enclosing portion reflects and guides light emitted by the light source 21a located therein to the liquid crystal panel 10. The reflector 22 has a plurality of such enclosing portions arranged in a matrix, and guides light from the light source 21a to the liquid crystal panel 10 for each dimming zone. A light diffusion plate may be provided between the reflector 22 and the liquid crystal panel 10.

[0021] The corresponding area C1 indicated by a dashed line in FIG. 3 is located behind the specific area R1 in FIG. 2 and is an example of an area composed of multiple dimming zones corresponding to the specific area R1. Although not shown, the backlight unit 20 is provided with corresponding areas corresponding to each of the other specific areas R2 to R4. The backlight unit 20 according to this embodiment illuminates the specific areas R1 to R4 with light with a higher luminance than the light illuminating the areas of the display area 10a other than the specific areas R1 to R4. That is, in the example of FIG. 3, the luminance of the light emitted from the light sources 21a located within the corresponding area C1 is higher than the luminance of the light emitted from the light sources 21a located outside the corresponding area C1. This ensures the luminance of the second light L2, described below. Furthermore, because it is not necessary to operate all of the multiple light sources 21a mounted on the circuit board 21 at high luminance, power consumption and heat generation can be reduced, thereby enabling the housing 40 to be made more compact.

[0022] Furthermore, it is preferable that adjacent areas among the multiple specific areas R1 to R4 (for example, specific area R1 and specific area R2, or specific area R2 and specific area R3, etc.) are spaced apart by a distance of at least one dimming zone. This makes it possible to avoid concentration of high heat-generating areas in the backlight unit 20, and allows heat to be efficiently dissipated from the housing 40 and heat dissipation section 50, which will be described later. As a result, it is possible to reduce the size of the housing 40.

[0023] The retardation section 30 is a film-like member provided to cover a portion of the display region 10a of the liquid crystal panel 10 and has a known configuration for tilting the polarization axis of incident light. For example, the retardation section 30 is formed of a λ / 2 retardation plate (also called a ½ wavelength plate). As described below, the retardation section 30 is provided so that its optical axis (advance axis or slow axis) is tilted by 45° with respect to the polarization direction of S-polarized light emitted from the liquid crystal panel 10 and incident on the retardation section 30. As a result, the S-polarized light incident on the retardation section 30 is emitted from the retardation section 30 as P-polarized light whose vibration direction is rotated by 90°. The retardation section 30 is attached to the upper surface of the liquid crystal panel 10 using optical bonding (OB), optical clear adhesive (OCA), optical double-sided tape, or the like. Note that a cover glass (not shown) may be interposed between the liquid crystal panel 10 and the retardation section 30.

[0024] The retardation units 30 of this embodiment are provided to cover each of the specific regions R1 to R4 shown in FIG. 2. Because the functions of the retardation units 30 provided in each of the specific regions R1 to R4 are similar, the function of the retardation unit 30 provided in the specific region R1 will be described as a representative example with reference to FIG. 4. The illumination light L0, which is light emitted from the multiple light sources 21a, is unpolarized light. The illumination light L0 becomes S-polarized light when it passes through the liquid crystal panel 10. Of this S-polarized light, a first light L1 emitted from an area where the retardation units 30 are not provided remains S-polarized and travels toward the ceramic formation portion 3a as shown in FIG. 1. Meanwhile, the S-polarized light incident on the retardation units 30 is converted into P-polarized light by the retardation units 30 and travels toward the ceramic formation portion 3a as second light L2 as shown in FIG. 1. The display light L emitted by the display device 100 toward the ceramic formation portion 3a includes a first light L1 and a second light L2. In other words, of the display light L, the light that travels from the display region 10a toward the ceramic forming portion 3a without passing through the phase difference portion 30 is the first light L1, and the light that travels from the specific region R1 toward the ceramic forming portion 3a through the phase difference portion 30 is the second light L2.

[0025] Due to the function of the phase difference section 30, P-polarized second light L2 is emitted toward the ceramic formation section 3a from the specific region R1 where content required by law is displayed. As a result, the light representing the content displayed in the specific region R1 reaches the user 4 as P-polarized light, allowing the user 4 wearing polarized sunglasses to clearly see the content required by law. The same applies to the content displayed in the other specific regions R2 to R4.

[0026] The housing 40 is configured to house the liquid crystal panel 10 and the backlight unit 20, and is made of resin or metal.

[0027] The heat dissipation unit 50 is a heat sink configured to dissipate heat from heat-generating elements such as the circuit board 21 inside the housing 40 to the outside of the housing 40. The heat dissipation unit 50 is made of resin or metal with high thermal conductivity. A forced air cooling device (not shown) such as a fan may be provided in combination with the heat dissipation unit 50. The heat dissipation unit 50 and the forced air cooling device are preferably positioned so as to be able to effectively cool the portions of the circuit board 21 that correspond to the specific regions R1 to R4.

[0028] The present invention is not limited to the above-described embodiments and drawings, and modifications (including the omission of components) can be made as appropriate within the scope of the present invention.

[0029] For ease of understanding, the above embodiment has been described as if the first light L1 is completely S-polarized and the second light L2 is completely P-polarized, but the polarization components of the first light L1 and the second light L2 are not limited to this. The second light L2 only needs to have a higher ratio of P-polarized components than the first light L1.

[0030] Moreover, a bezel (not shown) for hiding the end faces of the retardation section 30 may be provided above the liquid crystal panel 10 to partition the specific regions R1 to R4.

[0031] In the above description, in order to facilitate understanding of the present disclosure, descriptions of well-known technical matters have been omitted as appropriate.

[0032] This invention allows various embodiments and modifications without departing from the broad spirit and scope of this invention. Furthermore, the above-described embodiments are intended to explain this invention and do not limit the scope of this invention. That is, the scope of this invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of this invention. [Explanation of symbols]

[0033] 100…Display device 1...Vehicle 2...Dashboard, 2a...Cylindrical body 3...windshield, 3a...ceramic forming portion 4...User, 5...Eyebox 10... liquid crystal panel, 10a... display area 20...Backlight unit 21...circuit board, 21a...light source, 22...reflector 30…Phase difference part 40…Housing 50…Heat radiation part M1: First meter area, M2: Second meter area R1~R4…Specific area C1...Corresponding area L... display light, L1... first light, L2... second light, L0... illumination light

Claims

1. A display device that emits display light that displays an image toward a ceramic forming portion provided in a lower end region of a vehicle windshield, a liquid crystal panel having a display area illuminated by a backlight unit to display the image; a retardation unit provided to cover a part of the display area, The display area includes a specific area for displaying content required by law, the phase difference portion is provided to cover the specific region, Among the display light, light traveling from the display area toward the ceramic forming portion without passing through the retardation portion is defined as first light, and light traveling from the specific area toward the ceramic forming portion through the retardation portion is defined as second light. the second light has a higher ratio of P-polarized components than the first light; Display device.

2. Further comprising the backlight unit, the backlight unit has a plurality of light sources that can be controlled by local dimming, and illuminates the specific area with light having a luminance higher than that of light that illuminates an area other than the specific area of ​​the display area; The display device according to claim 1 .

3. the backlight unit further includes a lattice-shaped reflector surrounding each of the plurality of light sources and defining dimming zones the number of which corresponds to the number of the plurality of light sources; the display area includes a plurality of the specific areas, Adjacent areas among the plurality of specific areas are provided with an interval of at least one dimming zone. The display device according to claim 2 .

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