Vehicle display device

Abstract

The present invention provides a vehicle display device that can secure a visually appealing display area even while using multiple displays. [Solution] The vehicle display device 100 includes a first display unit 11 that emits a first display light representing a first image toward the user 1, a half mirror 20 that transmits the first display light, and a second display unit 12 that emits a second display light representing a second image toward the half mirror 20. The first display unit 11 and the second display unit 12 are located on opposite sides of the half mirror 20 and are provided at different positions in the width direction of the half mirror 20. The first display light transmitted through the half mirror 20 and the second display light reflected by the half mirror 20 allow the first image and the second image to be viewed by the user 1 side by side on the same plane. The half mirror 20 has a reflectivity increasing layer that increases the reflectivity of the P-polarized component of the second display light.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a vehicle display device that includes a display that emits display light representing an image toward a colored portion provided on the windshield of a vehicle, and allows a user to visually recognize an image represented by the display light reflected by the colored portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, when it is desired to allow a user to visually recognize an image of a larger size, a method of arranging a plurality of displays can be considered. However, for example, if only a plurality of displays are arranged in the width direction of the vehicle, the cases of adjacent displays may interfere with each other, or bezels of the displays may exist, resulting in a jagged arrangement of images being visually recognized, and there is a risk that the appearance of the display area (the area where an image is displayed to the user) will be impaired.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a vehicle display device capable of securing a display area with a good appearance while using a plurality of displays.

Means for Solving the Problems

[0006] To achieve the above object, a vehicle display device according to the present disclosure includes: a first display that emits first display light representing a first image toward a user; A half-mirror is provided at an angle to the first display and transmits the first display light, The system includes a second display that emits a second display light representing a second image toward the half mirror, The first display unit and the second display unit are located on opposite sides of the half mirror and are provided at different positions in the width direction of the half mirror. The first display light transmitted through the half-mirror and the second display light reflected by the half-mirror cause the first image and the second image to be visible to the user side by side on the same plane. The half-mirror has a reflectance-increasing layer, and the reflectance-increasing layer increases the reflectance of the P-polarized component of the second display light compared to when the reflectance-increasing layer is not formed on the half-mirror. [Effects of the Invention]

[0007] According to this disclosure, it is possible to secure a visually appealing display area even when using multiple displays. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic perspective view of a vehicle display device according to one embodiment of the present disclosure. [Figure 2] A schematic side view of a vehicle display device according to the same embodiment. [Figure 3] A diagram showing the configuration of a half-mirror according to the same embodiment. [Modes for carrying out the invention]

[0009] One embodiment of this disclosure will be described with reference to the drawings.

[0010] The vehicle display device 100 shown in Figures 1 and 2 is installed, for example, on the vehicle's dashboard (including the instrument panel) and is located on the side of the vehicle's windshield that is closer to the user 1. The user 1 is a passenger in the vehicle and is primarily the driver of the vehicle.

[0011] To facilitate understanding of the drawings, Figures 1 to 3 show the mutually orthogonal X, Y, and Z axes. The X-axis is the axis extending in the left-right direction, and its arrow points to the right. The Y-axis is the axis extending in the up-down direction, and its arrow points upward. The Z-axis is the axis extending in the front-back direction, and its arrow points backward. In this paper, the left-right, up-down, and front-back directions refer to the direction from User 1 (the same as the direction of the vehicle) unless otherwise specified.

[0012] The vehicle display device 100 comprises a plurality of displays 10 arranged in the left-right direction, a half-mirror 20, a control unit 30 (see Figure 2), and a viewpoint detection unit 40. The control unit 30 is mounted on a circuit board 31, for example, which is made of a PCB (Printed Circuit Board). The circuit board 31 is electrically connected to each of the plurality of displays 10, the viewpoint detection unit 40, and FPCs (Flexible Printed Circuits), etc. The operation of the plurality of displays 10 is controlled by the control unit 30, and various information about the vehicle is displayed.

[0013] As shown in Figure 1, the plurality of indicators 10 according to this embodiment include two first indicators 11 and one second indicator 12. Since each of the two first indicators 11 has similar characteristics in relation to the second indicator 12, one of the first indicators 11 will be described below.

[0014] As shown in Figure 2, the first display unit 11 emits a first display light L1 representing a first image toward the user 1. The first display unit 11 is composed of, for example, an LCD (Liquid Crystal Display) and displays the first image as an image under the control of the control unit 30. The first display unit 11 has a first display surface 11a for displaying the first image and a first bezel 11b surrounding the first display surface 11a. The first display surface 11a is rectangular when viewed from its normal direction. The first bezel 11b has a rectangular frame shape and its surface is treated with an anti-reflection coating. In other words, in the first display unit 11, the first bezel 11b is an area where the first image is not displayed.

[0015] As shown in Figure 2, the second display unit 12 emits a second display light L2 representing the second image toward the half mirror 20. The second display unit 12 emits the second display light L2 toward the upward. The second display unit 12 is composed of, for example, an LCD and displays the second image as an image under the control of the control unit 30. The second display unit 12 has a second display surface 12a for displaying the second image and a second bezel 12b surrounding the second display surface 12a. The second display surface 12a is rectangular when viewed from its normal direction. The second bezel 12b has a rectangular frame shape and its surface is treated with an anti-reflection coating. In other words, in the second display unit 12, the second bezel 12b is an area where the second image is not displayed.

[0016] The half-mirror 20 is positioned at an angle to the first display unit 11 and the second display unit 12. The half-mirror 20 transmits the first display light L1 from the first display unit 11 toward the user 1, while reflecting the second display light L2 from the second display unit 12 toward the user 1. As a result, the vehicle display device 100 allows the user 1 to view the first image represented by the first display light L1 and the second image represented by the second display light L2. Hereafter, when the user 1 views the first image, it may be expressed as the user 1 viewing the first display light L1. Similarly, when the user 1 views the second image, it may be expressed as the user 1 viewing the second display light L2.

[0017] As shown in Figure 3, the half-mirror 20 has a transparent substrate 21, a reflectance-increasing layer 22, and a transmittance-reducing layer 23. The transparent substrate 21 is formed in the shape of a plate from glass or resin.

[0018] The reflectivity increasing layer 22 is formed, for example, on the surface of the transparent substrate 21 on the side of the user 1. The reflectivity increasing layer 22 is configured to have a half mirror function that transmits and reflects incident light at a certain ratio, and an antireflection increasing function that increases the reflectivity of the P-polarized component of the second display light. The reflectivity increasing layer 22 having the half mirror function and the antireflection increasing function is composed of, for example, a dielectric multilayer film. Note that the half mirror function and the antireflection increasing function of the reflectivity increasing layer 22 may be realized by different types of films. For example, the half mirror function may be realized by a metal film, and the antireflection increasing function may be realized by a dielectric multilayer film. In any case, the reflectivity increasing layer 22 includes the reflecting surface of the half mirror 20 that reflects the second display light L2 toward the user 2.

[0019] The above-mentioned P-polarized light is P-polarized light with respect to the reflecting surface of the half mirror 20. In optics, the incident plane with respect to this reflecting surface is defined as the plane perpendicular to the reflecting surface and including the incident light ray and the reflected light ray. This P-polarized light is polarized light vibrating parallel to the incident plane. On the other hand, the S-polarized light with respect to the reflecting surface of the half mirror 20 is polarized light vibrating perpendicular to the incident plane. Here, the reflectivity of the P-polarized light in the half mirror 20 is lower than that of the S-polarized light. Also, although the polarization state of the second display light L2 reaching the half mirror 20 from the second display 12 can be arbitrarily set, in order for the user 1 wearing polarized sunglasses (the sunglasses are configured to cut S-polarized light) to be able to visually recognize the second display light L2 as well, the second display light L2 is often set to include a P-polarized component. Considering these, in order for the second display light L2 not to become too dark with respect to the first display light L1 visually recognized by the user 1, the half mirror 20 is provided with the reflectivity increasing layer 22.

[0020] In this way, the reflectivity increasing layer 22 increases the reflectivity of the P-polarized component of the second display light L2 compared to the case where the reflectivity increasing layer 22 is not formed on the half mirror 20. Note that increasing the reflectivity of the P-polarized component of the second display light L2 by the reflectivity increasing layer 22 is not limited to increasing only the reflectivity of the P-polarized component of the second display light L2. The reflectivity increasing layer 22 only needs to increase the reflectivity of at least the P-polarized component among the polarized components of the second display light L2.

[0021] The transmittance reduction layer 23 is a layer that reduces the transmittance of the first display light L1. For example, it is formed on the surface of the transparent substrate 21 opposite to the reflectance increase layer 22. The transmittance reduction layer 23 is composed of a light-transmissive printing layer or a light-transmissive film having a smoky color tone. Note that the transparent substrate 21 itself may have a smoky color tone. In this case, the transparent substrate 21 corresponds to the transmittance reduction layer 23.

[0022] In this way, the transmittance reduction layer 23 reduces the transmittance of the first display light L1 more than when the transmittance reduction layer 23 is not formed on the half mirror 20. Without any countermeasures, the transmittance of the first display light L1 passing through the half mirror 20 is higher than the reflectance of the second display light L2 reflected by the half mirror 20. Therefore, by providing the transmittance reduction layer 23 in this way, the appearance of the first display light L1 visually recognized by the user 1 can be made closer to that of the second display light L2.

[0023] Note that an antireflection film such as an AR (Anti-Reflection) coat may be provided on the side of the half mirror 20 where the transmittance reduction layer 23 is located. Also, in the half mirror 20, if the reflectance increase layer 22 is provided at a position closer to the user 1 than the transmittance reduction layer 23, the arrangement of the reflectance increase layer 22 and the transmittance reduction layer 23 is not limited to the example in FIG. 3 and is arbitrary.

[0024] The first display 11 and the second display 12 are located on opposite sides of each other with the half mirror 20 interposed therebetween, and are provided at different positions in the width direction (left-right direction) of the half mirror 20. Also, as particularly shown in FIG. 2, the first display 11 and the second display 12 are arranged symmetrically with respect to the half mirror 20. "The first display 11 and the second display 12 are arranged symmetrically with respect to the half mirror 20" specifically means that the first display surface 11a and the second display surface 12a are arranged symmetrically with respect to the reflection surface of the half mirror 20.

[0025] With this arrangement, the first display light L1 transmitted through the half mirror 20 and the second display light L2 reflected by the half mirror 20 allow the first and second images to be viewed adjacent to each other on the same plane by the user 1. Here, as shown in Figure 1, the second image viewed through the half mirror 20 by the second display light L2 reflected by the half mirror 20 is called the reflected image V2. For the user 1, this reflected image V2 is viewed adjacent to the first image on a virtual plane including the first display surface 11a. In this way, the vehicle display device 100 makes it possible to secure a visually appealing display area even when using multiple displays 10.

[0026] Furthermore, in the vehicle display device 100 according to this embodiment, the images projected by the first bezel 11b or the second bezel 12b are viewed by the user 1 continuously on the same plane, without any break between the first and second images that are visible on the same plane. This can be achieved by adjusting the relative positions of the first display device 11 and the second display device 12 such that, considering the portion of the first bezel 11b closer to the second display device 12 and the portion of the second bezel 12b closer to the first display device 11 in the left-right direction, the other part of the first bezel 11b and the other part of the second bezel 12b overlap at a position symmetrical with respect to the reflective surface of one of the half-mirrors 20 of the first bezel 11b and the second bezel 12b. Furthermore, the relative arrangement of the first display unit 11 and the second display unit 12 is adjusted so as to satisfy the following conditions in the left-right direction: (i) the edge of the reflected image V2 and the edge of the first display surface 11a coincide, or (ii) a portion of the reflected image V2 and the first display surface 11a overlap. With this relative arrangement of the first display unit 11 and the second display unit 12, the user 1 appears to see the first image and the second image as seamlessly continuing in the left-right direction through the half mirror 20. In other words, with the vehicle display device 100, even if a relatively small number of displays 10 are used, a large, continuous display area can be secured.

[0027] The vehicle display device 100 may also be equipped with a hood that covers the first display unit 11 and the half mirror 20 while allowing the user 1 to see the reflective surface of the half mirror 20. This hood prevents external light, such as sunlight, from entering between the first display unit 11 and the half mirror 20. The vehicle display device 100 may also be equipped with a smoked cover glass on the side of the half mirror 20 that is closer to the user 1. This cover glass makes the presence of the first display unit 11 and the second display unit 12 less noticeable when the first display light L1 and the second display light L2 are not being emitted.

[0028] The viewpoint detection unit 40 has a well-known configuration for detecting the viewpoint position of user 1 and transmits information indicating the detected viewpoint position of user 1 to the control unit 30. The viewpoint detection unit 40 is composed of an infrared camera, a visible light camera, a millimeter-wave radar, etc., installed inside the vehicle's interior, and its arrangement is arbitrary.

[0029] The control unit 30 controls the operation of the first display unit 11 and the second display unit 12, and acquires information indicating the user 1's viewpoint position from the viewpoint detection unit 40. The control unit 30 is composed of a microcontroller including a CPU (Central Processing Unit) and memory, and various drive circuits, and controls the overall operation of the vehicle display device 100 according to the program stored in the memory. The memory is a well-known configuration including ROM (Read Only Memory), RAM (Random Access Memory), etc.

[0030] The control unit 30 adjusts the color tone of at least one of the first display light L1 and the second display light L2 based on the optical characteristic information D stored in memory. Adjusting the color tone of the first display light L1 means adjusting the gradation of the image (first image) displayed by the first display unit 11 itself (including adjusting the brightness determined according to the gradation). Similarly, adjusting the color tone of the second display light L2 means adjusting the gradation of the image (second image) displayed by the second display unit 12 itself (including the brightness determined according to the gradation).

[0031] Here, the color tone of the first display light L1 changes after it passes through the transmittance reduction layer 23, which has a smoky color, compared to the first display light L1 before it reaches the half mirror 20. Also, the color tone of the second display light L2 reflected by the reflectance increasing layer 22 may change compared to the second display light L2 before it reaches the half mirror 20, due to the reflectance characteristics of the reflectance increasing layer 22. Taking this into consideration, the optical characteristic information D is data configured to show at least one of the color tone changes of the first display light L1 before and after it passes through the half mirror 20, and the color tone changes of the second display light L2 before and after it is reflected by the half mirror 20.

[0032] For example, if the color specifications of the first display unit 11 and the second display unit 12 are such that the R (red), G (green), and B (blue) subpixels are each represented by 8 bits, then the RGB subpixels are each represented by 256 gradations from 0 to 255. In other words, if the color tone of any pixel constituting the image is represented as R(x), G(y), and B(z), then x, y, and z each represent values ​​from 0 to 255. In this case, the optical characteristic information D only needs to show the correction values ​​for x, y, and z, taking into account at least one of the color tone changes of the first display light L1 and the color tone changes of the second display light L2. For example, these correction values ​​only need to be defined for each color specified by the control unit 30 for each pixel. Also, when adjusting the color tones of both the first display light L1 and the second display light L2, the correction values ​​for the first display unit 11 and the correction values ​​for the second display unit 12 will be different.

[0033] The control unit 30 may, based on the optical characteristic information D, adjust the color tone of the first display light L1 (the color tone of the display image of the first display unit 11) only, (ii) adjust the color tone of the second display light L2 (the color tone of the display image of the second display unit 12) only, or (iii) adjust the color tones of both the first display light L1 and the second display light L2, so as to bring the relative colors of the first display light L1 and the second display light L2 visible to the user 1 closer together.

[0034] The same approach to correction values ​​applies when each of the R, G, and B subpixels is represented by a number other than 8 bits (for example, 10 bits, 12 bits). Furthermore, when the first display unit 11 and the second display unit 12 display a monochrome image, the optical characteristic information D only needs to be data that corrects the degree of brightness / darkness (white / black) specified for each pixel, taking into account at least one of the color tone changes of the first display light L1 and the color tone changes of the second display light L2.

[0035] Here, depending on the reflection characteristics and wavelength dependence of the half mirror 20 according to the viewpoint position of user 1, there is a risk that a difference may occur between the wavelength of transmitted light and the wavelength of reflected light. Taking this into consideration, the optical characteristic information D may be configured to show the optical characteristics of light transmission and reflection in the half mirror 20 according to the viewpoint position of user 1. For example, as mentioned above, if the color tone of any pixel constituting the image is expressed as R(x), G(y), and B(z), then the optical characteristics according to the viewpoint position of user 1 should show the correction values ​​of x, y, and z, which take into account both the color tone change of the first display light L1 and the color tone change of the second display light L2, determined according to the viewpoint position of user 1. Based on the optical characteristic information D configured in this way, the control unit 30 may identify the optical characteristics at the viewpoint position acquired from the viewpoint detection unit 40, and adjust the color tones of the first display light L1 and the second display light L2 based on the identified optical characteristics. Thus, considering the viewpoint position of user 1, it is preferable for the control unit 30 to adjust the color tone of both the first display light L1 and the second display light L2. Therefore, the correction value for the first display unit 11 and the correction value for the second display unit 12 are different, and each correction value is determined according to the viewpoint position of user 1. In this way, by adjusting the color tone of the first display light L1 and the second display light L2 using optical characteristic information D that takes into account the viewpoint position of user 1, the appearance of the first image and the second image as seen by user 1 can be made similar, and display quality can be ensured for users 1 of various postures and body types.

[0036] Furthermore, in order to accommodate the installation tolerances of the first display unit 11 and the second display unit 12, the display areas of adjacent first display unit 11 and second display unit 12 may be superimposed, and the same content may be displayed in each overlapping display area, or content may not be displayed in one of the overlapping display areas.

[0037] The present invention is not limited by the embodiments and drawings described above. Modifications (including the deletion of components) can be made as appropriate, without altering the essence of the invention.

[0038] The above example shows a configuration in which multiple displays 10 consist of two first displays 11 and one second display 12. However, it may also consist of one first display 11 and one second display 12, or the number of displays can be arbitrary as long as the first displays 11 and second displays 12 are arranged alternately in the width direction (left-right direction) of the half mirror 20.

[0039] At least one of the first display unit 11 and the second display unit 12 may be a display other than an LCD, such as an OLED (Electro-Luminescence) display or a display using a projector. When a display using a projector is used, a transmissive screen onto which the first image is projected constitutes the first display surface 11a, and a transmissive screen onto which the second image is projected constitutes the second display surface 12a. Furthermore, at least one of the first display unit 11 and the second display unit 12 may be a bezel-less display.

[0040] Furthermore, at least one of the first display unit 11 and the second display unit 12 is not limited to displaying an image formed by a combination of pixels, but may also be an indicator display that illuminates at least one of the characters, figures, and icons applied to the design plate using illumination light from an LED (Light-Emitting Diode). If one of the first display unit 11 and the second display unit 12 is an indicator display and the other displays an image formed by a combination of pixels, it is difficult to perfectly match the color tones of the first image and the second image. In this case, the control unit 30 only needs to match the appearance of the first image and the second image based on the optical characteristic information D to the extent that it does not cause discomfort to the user 1.

[0041] Furthermore, the statement that the first image and the second image are visible to user 1 adjacent to each other on the same plane is arbitrary, as long as the first image and the second image are not separated by the image of the first bezel 11b or the second bezel 12b (i.e., the image of the part of the image that cannot be displayed), and includes not only (i) the first image and the second image being visible to user 1 continuously on the same plane, but also (ii) the first image and the second image being visible to user 1 with a gap between them on the same plane.

[0042] The light transmittance and reflectance of the half mirror 20 do not have to be the same, and may be different. For example, the light transmittance and reflectance of the half mirror 20 may be adjusted according to the display brightness of the first display unit 11 and the second display unit 12. Furthermore, the half mirror 20 is not limited to a flat plate shape, but may be a curved plate shape, as long as the first image and the second image can be viewed by the user 1 adjacent to each other on the same plane.

[0043] In the above explanation, explanations of publicly known technical matters have been omitted where appropriate to facilitate understanding of this disclosure.

[0044] This invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of this invention is indicated not by the embodiments, but by the claims. Various modifications made within the scope of the claims and the equivalent scope of the meaning of the invention are considered to be within the scope of this invention. [Explanation of symbols]

[0045] 100...Vehicle display device, 1...User 10…Multiple displays 11...1st display, L1...1st display light 11a...First display surface, 11b...First bezel 12...Second display, L2...Second display light 12a...Second display surface, 12b...Second bezel 20... Half mirror 21...Transparent base material 22…Reflectance-increasing layer 23... Transmittance reduction layer 30...Control unit, 31...Circuit board 40... Viewpoint detection unit V2…Reflection image D...Optical property information

Claims

1. A first display unit that emits a first display light representing a first image toward the user, A half-mirror is provided at an angle to the first display and transmits the first display light, The system includes a second display that emits a second display light representing a second image toward the half mirror, The first display unit and the second display unit are located on opposite sides of the half mirror and are provided at different positions in the width direction of the half mirror. The first display light transmitted through the half-mirror and the second display light reflected by the half-mirror cause the first image and the second image to be visible to the user side by side on the same plane. The half-mirror has a reflectance-increasing layer, and the reflectance-increasing layer increases the reflectance of the P-polarized component of the second display light compared to when the reflectance-increasing layer is not formed on the half-mirror. Vehicle display device.

2. The half-mirror has a transmittance-reducing layer on the side of the first display unit that is closer to the reflectance-increasing layer, and the transmittance-reducing layer reduces the transmittance of the first display light compared to when the transmittance-reducing layer is not formed on the half-mirror. The vehicle display device according to claim 1.

3. The system further comprises a control unit that controls the operation of the first display and the second display, The aforementioned light transmittance reduction layer has a smoky color, The control unit adjusts the color tone of at least one of the first display light and the second display light based on predetermined optical characteristic information that indicates at least one of the color tone changes of the first display light before and after it passes through the half mirror, and the color tone changes of the second display light before and after it is reflected by the half mirror. The vehicle display device according to claim 2.

4. The control unit, The viewpoint position is obtained from the viewpoint detection unit that detects the user's viewpoint position. Based on the optical properties information configured to show the optical properties of light transmission and reflection in the half mirror according to the viewpoint position, the optical properties at the viewpoint position obtained from the viewpoint detection unit are identified. Based on the identified optical characteristics, the color tones of the first display light and the second display light are adjusted. The vehicle display device according to claim 3.

5. The first image and the second image are viewed by the user in succession on the same plane. A vehicle display device according to any one of claims 1 to 4.

Images