Display device for vehicle

Abstract

To provide a display device for a vehicle capable of making an image more easily visible, even if a double image is made visible.SOLUTION: An image display unit 20 displays an image in which multiple arrows having identical shapes are arranged side by side in a horizontal direction. A control unit 23 calculates a binocular parallax (X), which is a deviation amount in a horizontal direction, of a double image of an image visible by a driver 200 resulting from a distance difference between a display distance L1 of the image and a gazing point distance L2 of the driver 200, and adjusts a pitch (Lp) in the horizontal direction of the arrow displayed in the image to binocular parallax (X) / integer (n).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a display device for a vehicle. [Background technology]

[0002] Conventionally, there have been known display devices for vehicles, such as head-up displays, which allow a driver to view an image as a virtual image from the driver's eye position (eye point). In such head-up displays, as shown in Fig. 2 and Fig. 7, the driver may view a double image due to the difference in distance between the display distance L1 of the image (virtual image) and the gaze point distance L2 where the driver is gazing. This has led to a problem that the image is difficult to view.

[0003] Furthermore, a display control device described in Patent Document 1 has been proposed as a technology for suppressing the appearance of double images. The display control device in Patent Document 1 sets the image display time to a time longer than the time required for the dominant eye to completely recognize the image and shorter than the time required for the non-dominant eye to completely recognize the image. However, the technology in Patent Document 1 mentioned above limits the image display time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-80984 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a vehicle display device that makes it easy to view an image even if a double image is viewed. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the vehicle display device according to the present invention has the following features. an image display unit that emits display light for an image; an optical system that projects display light emitted from the image display unit toward a reflective surface in front of a driver; A control unit that controls the image display unit, the image display unit displays the image in which a plurality of designs of the same shape are arranged in a horizontal direction of the driver, The control unit calculates a binocular disparity, which is a horizontal shift amount in a double image of the image visually recognized by the driver due to a distance difference between a display distance of the image and a gaze point distance of the driver, and adjusts the horizontal pitch of the design displayed on the image to a value obtained by dividing the binocular disparity by an integer. It is a display device for vehicles. Effect of the Invention

[0007] According to the present invention, it is possible to provide a display device for a vehicle that makes it easy to view an image even if a double image is viewed.

[0008] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following description of the embodiment of the present invention (hereinafter, referred to as "embodiment") with reference to the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of a display device for a vehicle according to the present invention. [Diagram 2] FIG. 2 is a diagram showing the relationship between the driver's eyes, the display distance of an image displayed on the image display unit shown in FIG. 2, and the driver's gaze distance. [Diagram 3] FIG. 3(A) shows an image displayed on the image display unit shown in FIG. 2, and FIG. 3(B) shows an image viewed by the driver when X=Lp. [Figure 4] FIG. 4 is a flowchart illustrating a processing procedure of the control unit shown in FIG. [Diagram 5]FIG. 5 is a graph showing the relationship between the fixation point distance and the binocular disparity (angle). [Figure 6] FIG. 6 shows the image seen by the driver when X=2Lp. [Figure 7] FIG. 7 shows an image conventionally viewed by a driver. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0011] For the sake of convenience, the following definitions are used for the terms "front", "rear", "left", "right", "upper" and "lower" as shown in Figures 1 and 2. The "front-rear direction", "left-right direction" and "up-down direction" are mutually orthogonal. The left-right direction corresponds to the "horizontal direction" of the present invention.

[0012] As shown in Fig. 1, the vehicle display device 1 of this embodiment is mounted on a vehicle 100 and constitutes a head-up display. The vehicle display device 1 is disposed, for example, inside an instrument panel 101. The instrument panel 101 has an opening 101a that opens upward. The opening 101a faces a windshield 102 in the up-down direction of the vehicle 100.

[0013] The vehicle display device 1 has a housing 4, a cover 5, an image display unit 20, a control unit 23, and an optical system 25. The image display unit 20, the control unit 23, and the optical system 25 are housed inside the housing 4. The housing 4 has a main body 2 and a lid member 3 that engages with the main body 2. The main body 2 has an opening that opens upward. The lid member 3 closes the opening of the main body 2 from above. The lid member 3 has a wall portion 30 that faces the opening 101a. The wall portion 30 has an opening 31 that opens upward. The housing 4 is arranged so that the opening 31 faces the opening 101a. The cover 5 is a plate-shaped member that closes the opening 31 of the lid member 3. The cover 5 is formed of a translucent resin such as polycarbonate (PC) or acrylic.

[0014] The image display unit 20 is a device that emits display light 70 of an image. The illustrated image display unit 20 is a liquid crystal display device, for example, a TFT-LCD (Thin Film Transistor-Liquid Crystal Display). However, the image display unit 20 is not limited to a liquid crystal display device. The image display unit 20 may be, for example, a device that scans laser light to generate an image on a transparent screen.

[0015] The optical system 25 has a first mirror 21 and a second mirror 22. The first mirror 21 reflects the display light 70 emitted from the image display unit 20 toward the second mirror 22. The first mirror 21 is, for example, a flat mirror. The second mirror 22 reflects the display light 70 toward the windshield 102. The shape of the reflecting surface of the second mirror 22 is, for example, a free-form surface. The second mirror 22 is, for example, a concave mirror that magnifies the display light 70.

[0016] The display light 70 reflected by the second mirror 22 passes through the opening 31 and the opening 101a, and is reflected by the reflecting surface 102a of the windshield 102 toward the driver 200. A virtual image is formed by the display light 70 incident on the pupil 201 of the driver 200. The instrument panel 101 is provided with a cylindrical wall portion 103. The wall portion 103 surrounds the optical path of the display light 70 traveling from the opening 31 toward the opening 101a.

[0017] The control unit 23 has a control circuit configured to control the image display unit 20. The control unit 23 is mounted on, for example, a control board arranged inside the housing 4. The control unit 23 controls the image display unit 20 to generate an image according to, for example, a program stored in advance.

[0018] The vehicle 100 has a driver monitor 104. The driver monitor 104 includes a camera disposed in front of the driver 200. The driver monitor 104 captures an image of the driver 200 to generate a driver image. The driver monitor 104 detects the position of the pupils 201 of the driver 200 based on the driver image. The detection result by the driver monitor 104 is sent to the control unit 23.

[0019] Incidentally, an image displayed on the image display unit 20 and viewed by the driver 200 as a virtual image may be viewed as a double image. This is because, as shown in FIG. 2, when there is a distance difference between the display distance L1 of the image (virtual image) and the gaze point distance L2 (for example, a car 100 m ahead) viewed by the driver 200, a binocular parallax (distance) X occurs in the images viewed by the right eye and the left eye of the driver 200. That is, the right eye of the driver 200 views a right-eye image at an intersection I11 between a line L31 connecting the right eye and the image and the gaze point distance L2. The left eye of the driver 200 views a left-eye image at an intersection I12 between a line L32 connecting the left eye and the image and the gaze point distance L2. These right-eye image and left-eye image are shifted in the horizontal direction. The amount of this shift is the binocular parallax (distance) X. This causes a problem that the images are difficult to view because a double image shifted by binocular disparity (distance) X is displayed as shown in Figure 7. In Figure 7, the dashed line indicates the right-eye image, and the dashed line indicates the left-eye image.

[0020] Therefore, as shown in FIG. 3, when displaying multiple arrows (designs) of the same shape (three in FIG. 3) arranged in a horizontal direction as lane change information such as right / left turns, merging, and branching, the control unit 23 adjusts the horizontal pitch of the arrows to be Lp=binocular disparity (distance) X / integer n. FIG. 3(A) shows an image displayed on the image display unit 20. FIG. 3(B) shows an image viewed by the driver 200 when adjusted to integer n=1, that is, pitch Lp=binocular disparity (distance) X. In FIG. 3(B), the dashed line indicates the right-eye image, and the dashed line indicates the left-eye image. As shown in FIG. 3(B), the leftmost arrow in the left-eye image shown by the dashed line and the second arrow from the right in the right-eye image shown by the dashed line are displayed at the same horizontal display position, and they are perfectly overlapped. Therefore, even if a double image is displayed, the image is easily viewed.

[0021] Next, the operation of the control unit 23 outlined above will be described with reference to the flowchart in Fig. 4. The control unit 23 must communicate with the navigation device to provide direction instructions, and starts processing at the timing when an image of three identically shaped arrows arranged horizontally as shown in Fig. 3(A) is displayed. First, the control unit 23 calculates the binocular disparity (distance) X (S2).

[0022] In this embodiment, the binocular disparity (distance) X can be calculated by the following formula (1) as shown in FIG. X = T × (L2-L1) / L1 … Equation (1) T: Driver 200's eye distance

[0023] Since the eye distance T (see FIG. 2) does not vary greatly from person to person, in this embodiment, an average value is stored in advance in a storage unit (not shown). Since the display distance L1 can be obtained in advance from the arrangement position of the optical system 25, in this embodiment, the previously obtained display distance L1 is stored in a storage unit. The gaze point distance L2 can be obtained from the convergence angle θ2 when gazing at the gaze point distance L2 and the eye distance T using the following formula (2). L2=T / {2×tan(θ2 / 2)} …Equation (2)

[0024] The convergence angle θ2 (see FIG. 2) can be detected from the position of the iris 201 detected by the driver monitor 104 using a known technique. In this embodiment, the control unit 23 detects the convergence angle θ2 at the gaze point distance L2 from the position of the iris 201 detected by the driver monitor 104, and can obtain the binocular disparity (distance) X by substituting the measured convergence angle θ2, the eye distance T stored in the storage unit, and the display distance L1 into the formulas (1) and (2). Thereafter, the control unit 23 displays an image in which the pitch Lp is adjusted to the binocular disparity (distance) X (S2), and returns to S1 again. Through the above operation, the control unit 23 can make the pitch Lp of the arrows the same as the binocular disparity (distance) X, and as shown in FIG. 3(B), the image can be easily viewed even if a double image is displayed.

[0025] The present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, etc. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary as long as the present invention can be achieved, and are not limited.

[0026] In the above-described embodiment, the eye distance T is set to a predetermined average value, but is not limited to this. When the driver monitor 104 detects the eye distance T based on the driver image, the detection result from the driver monitor 104 may be obtained to obtain the eye distance T.

[0027] In the above embodiment, the fixation point distance L2 is calculated from the convergence angle θ2 detected from the driver image of the driver monitor 104, and the binocular disparity (distance) X is calculated from the fixation point distance L2, but this is not limited to the above. The fixation point distance L2, i.e., the convergence angle θ2, changes from moment to moment. The binocular disparity (angle) θ1-θ2, which is the difference between the convergence angle θ2 at the fixation point distance L2 and the convergence angle θ1 at the display distance L1 (see FIG. 2), is as shown in FIG. 5.

[0028] The convergence angle θ1 can be calculated from the following formula (3), and the convergence angle θ2 can be calculated from the following formula (4). θ1=atan{(T / 2) / L1}×2 …Equation (3) θ2=atan{(T / 2) / L2}×2 …Equation (4)

[0029] Figure 5 shows the results of calculating the binocular disparity (angle) θ1-θ2 when the eye distance T is set to 65 mm, which is midway between the general range of 60 mm to 70 mm, the display distance L1 is set to 2 m, and the gaze point distance L2 is changed from 2 m to 100 m.

[0030] As shown in the figure, the relationship between the binocular disparity (angle) θ1-θ2 and the fixation point distance L2 changes significantly up to a fixation point distance L2 of 10 m (a specified distance), but changes little at 10 m or more. Since the binocular disparity (distance) X and the binocular disparity (angle) θ1-θ2 are proportional to each other according to equations (1) and (2), the relationship between the binocular disparity (distance) X and the fixation point distance L2 also changes significantly up to 10 m, but changes little at 10 m or more.

[0031] Therefore, when the fixation point distance L2 calculated from the detected convergence angle θ2 is 10 m or more, the control unit 23 may calculate the binocular disparity (distance) X as a predetermined constant value. As a result, when the fixation point distance L2 is 10 m or more, even if the fixation point distance L2 changes from moment to moment, the pitch Lp does not change from moment to moment accordingly.

[0032] Furthermore, in the case of a vehicle equipped with a sensor that detects the distance to a preceding vehicle, such as an ADAS (Advanced Driving Assistant System), the detected distance of the sensor is input to the control unit 23. The control unit 23 may function as an acquisition unit and acquire the distance to the preceding vehicle as the gaze point distance L2 to obtain the binocular disparity (distance) X. In this case as well, when the distance to the preceding vehicle is 10 m or more, the binocular disparity (distance) X may be set to a predetermined constant value.

[0033] Furthermore, if the navigation device mounted on the vehicle displays the remaining distance to the lane change location, the distance is input to the control unit 23. The control unit 23 may function as an acquisition unit and acquire the remaining distance as the gaze point distance L2 to obtain the binocular disparity (distance) X. In this case as well, if the remaining distance is 10 m or more, the binocular disparity (distance) X may be set to a predetermined constant value.

[0034] In the above embodiment, the pitch Lp is set to the binocular disparity (distance) X with the integer n=1, but this is not limited to the above. For example, if the binocular disparity (distance) X is large, the integer n=2 may be used. When the integer n=2 is used, as shown in FIG. 6, the rightmost arrow of the right-eye image shown by the dashed line and the leftmost arrow of the left-eye image shown by the dashed line match in the horizontal direction and overlap perfectly, so that even a double image can be easily viewed. In this way, the integer n may be appropriately set according to the magnitude of the binocular disparity (distance) X.

[0035] Here, the features of the above-mentioned embodiment of the display device for a vehicle according to the present invention will be briefly summarized and listed in the following [1] to [5].

[0036] [1] an image display unit (20) that emits image display light (70); an optical system (25) that projects display light (70) emitted from the image display unit (20) toward a reflecting surface in front of a driver (200); A control unit (23) that controls the image display unit (20), The image display unit (20) displays the image in which a plurality of designs (arrows) of the same shape are arranged in the horizontal direction of the driver (200), The control unit (23) calculates a binocular disparity (X), which is a horizontal (left-right) shift amount in a double image of the image visually recognized by the driver (200) due to a difference in distance between a display distance (L1) of the image and a gaze point distance (L2) of the driver (200), and adjusts the horizontal pitch (Lp) of the design displayed on the image to a value obtained by dividing the binocular disparity (X) by an integer (n). Vehicle display device (1).

[0037] According to the configuration of [1] above, by adjusting the pitch (Lp) to binocular disparity (X) / integer (n), the horizontal display positions of the right-eye image design and the left-eye image design that make up the double image become the same and overlap perfectly. Therefore, even if a double image is displayed, the image is easy to see.

[0038] [2] In the vehicle display device (1) described in [1], An acquisition unit (23) that acquires the gaze point distance (L2) from the driver (200), The control unit (23) calculates the binocular disparity (X) based on the gaze point distance (L2) acquired by the acquisition unit (23). Vehicle display device (1).

[0039] According to the configuration [2] above, the binocular disparity (X) can be easily calculated based on the fixation point distance (L2).

[0040] [3] In the vehicle display device (1) described in [2], When the gaze point distance (L2) acquired by the acquisition unit (23) is equal to or greater than a predetermined distance, the control unit (23) determines a predetermined constant value as the binocular disparity (X). Vehicle display device (1).

[0041] According to the configuration of [3] above, when the fixation distance (L2) is equal to or greater than a predetermined distance, the change in the binocular disparity (X) is small. Therefore, when the fixation distance (L2) is equal to or greater than a predetermined distance, the pitch (Lp) of the design (arrow) does not change from moment to moment even if the fixation distance (L2) changes from moment to moment.

[0042] [4] In the vehicle display device (1) described in [2], The acquisition unit (23) acquires the distance to the preceding vehicle as the gaze point distance (L2). Vehicle display device (1).

[0043] According to the configuration [4] above, the fixation point distance (L2) can be easily obtained and the binocular disparity (X) can be calculated.

[0044] [5] In the vehicle display device (1) described in [2], The acquisition unit (23) acquires a remaining distance from a navigation device to a course change point as the gaze point distance (L2). Vehicle display device (1).

[0045] According to the configuration of [5] above, the fixation point distance (L2) can be easily obtained and the binocular disparity (X) can be calculated. [Explanation of symbols]

[0046] 1 Vehicle display device 20 Image display unit 23 Control unit (acquisition unit) 25 Optical system 70 display light 200 Drivers L1 display distance L2 Gaze point distance Lp Pitch X Binocular disparity (distance)

Claims

1. an image display unit that emits display light for an image; an optical system that projects display light emitted from the image display unit toward a reflective surface in front of a driver; A control unit that controls the image display unit, the image display unit displays the image in which a plurality of designs of the same shape are arranged in a horizontal direction of the driver, The control unit calculates a binocular disparity, which is a horizontal shift amount in a double image of the image visually recognized by the driver due to a distance difference between a display distance of the image and a gaze point distance of the driver, and adjusts the horizontal pitch of the design displayed on the image to a value obtained by dividing the binocular disparity by an integer. Vehicle display device.

2. The display device for a vehicle according to claim 1, an acquisition unit that acquires the gaze point distance from the driver, The control unit calculates the binocular disparity based on the gaze point distance acquired by the acquisition unit. Vehicle display device.

3. The display device for a vehicle according to claim 2, When the gaze point distance acquired by the acquisition unit is equal to or greater than a predetermined distance, the control unit determines a predetermined constant value as the binocular disparity. Vehicle display device.

4. The display device for a vehicle according to claim 2, The acquisition unit acquires a distance to a leading vehicle as the gaze point distance. Vehicle display device.

5. The display device for a vehicle according to claim 2, The acquisition unit acquires a remaining distance from a navigation device to a course change point as the gaze point distance. Vehicle display device.

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