JP2023044419A - head-up display device - Google Patents

Abstract

To provide a head-up display device that can be reduced in a size.SOLUTION: A head-up display device projects display light L on a windshield to allow a viewer having a viewpoint in a visible area to view a virtual image. The head-up display device comprises: a display unit that emits the display light L; a first mirror 11 that has a reflection surface 11a reflecting the display light L emitted from the display unit; and a second mirror 12 that reflects the display light L reflected on the first mirror 11 toward the windshield. The rays of display light L intersect each other at cross points CP2, CP3 in a height direction. Part of the reflection surface 11a of the first mirror 11 is included in a virtual circle C with a line segment connecting the cross points CP2, CP3 as a diameter D. The cross point CP2 is a point at which the rays of display light L intersect each other which correspond to a viewpoint at an upper end of the visible area in the height direction. The cross point CP3 is a point at which the rays of display light L intersect each other which correspond to a viewpoint at a lower end of the visible area in the height direction.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to a head-up display device.

For example, the head-up display device described in Patent Document 1 includes a display that emits display light, a first mirror that reflects the display light emitted by the display, and display light that is reflected by the first mirror. and a second mirror that reflects the The first mirror vertically crosses the reflected display light at a crossing point before reaching the second mirror.

WO2018/198821

In the configuration described in Patent Document 1, it is necessary to arrange various members such as the first mirror and the second mirror so as not to block the optical path of the display light, which increases the size of the head-up display device.

The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a head-up display device that can be downsized.

In order to achieve the above object, a head-up display device according to the present disclosure is a head-up display device that allows a viewer whose viewpoint is within a visible region to visually recognize a virtual image by projecting display light onto a projected member. a display unit for emitting the display light; a first mirror having a reflecting surface for reflecting the display light emitted from the display unit; and a second mirror that reflects toward the second mirror, wherein the display light intersects at a first cross point and a second cross point in a specific direction, and at least a portion of the reflective surface of the first mirror reflects the first The display light is included in a virtual circle having a diameter of a line segment connecting the cross point and the second cross point, and the first cross point corresponds to a viewpoint at a first end of the visible region in the specific direction. and the second crossing point is a point at which the display light corresponding to the viewpoint of the second end opposite to the first end of the visible region in the specific direction intersects. .

According to the present disclosure, it is possible to reduce the size of the head-up display device.

1 is a schematic diagram of a vehicle according to an embodiment of the present disclosure; FIG. 1 is a schematic diagram of a head-up display device according to an embodiment of the present disclosure; FIG. 1 is a schematic diagram of a head-up display device when a viewpoint is positioned at the center of a visible area according to an embodiment of the present disclosure; FIG. 1 is a schematic diagram of a head-up display device when a viewpoint is positioned at the upper end of a visible area according to an embodiment of the present disclosure; FIG. 1 is a schematic diagram of a head-up display device when a viewpoint is positioned at the lower end of a visible area according to an embodiment of the present disclosure; FIG. FIG. 4 is a schematic diagram showing an optical path of display light viewed from the width direction according to an embodiment of the present disclosure; FIG. 5 is a schematic diagram showing an optical path of display light viewed from the width direction according to a comparative example; FIG. 10 is a schematic diagram showing an optical path of display light viewed from the width direction according to a modification of the present disclosure;

An embodiment of a head-up display device according to the present disclosure will be described with reference to the drawings.
As shown in FIG. 1 , head-up display device 100 is mounted on a dashboard of vehicle 200 . The head-up display device 100 projects the display light L onto the windshield 201, which is a projected member, so that a virtual image V including vehicle information is displayed in the virtual image display area K by the viewer 1 (for example, the driver of the vehicle 200). be visible. When the viewpoints EP1, EP2, and EP3 of the viewer 1 are within the visible region R, the viewer 1 can visually recognize the virtual image V.

As shown in FIG. 2 , the head-up display device 100 includes a first mirror 11 , a second mirror 12 , a display section 20 and a case 30 .
The case 30 is formed in a box shape from light-shielding resin or metal. The case 30 accommodates the first mirror 11 , the second mirror 12 and the display unit 20 . The case 30 includes a window portion 31 made of a light transmissive member that transmits the display light L generated in the internal space of the case 30 toward the windshield 201 .

The display unit 20 has a light emitting surface 21 that emits display light L representing an image. The display unit 20 may be of a type having a liquid crystal panel and an illumination device, or may be of a type having a reflective display element such as a DMD (Digital Micromirror Device) element and a projector. In this example, the display unit 20 emits the display light L as diffused light. The light emitting surface 21 faces the rear upper side of the vehicle. The image displayed on the light emitting surface 21 is subjected to distortion correction for correcting the distortion of the virtual image V viewed by the viewer 1 .

As shown in FIG. 2, the first mirror 11 is a curved mirror that is concavely curved along the height direction of the vehicle and linearly extends along the width direction of the vehicle. The first mirror 11 may be curved concavely or convexly in the width direction of the vehicle. The first mirror 11 reflects the display light L emitted from the display unit 20 toward the second mirror 12 . A reflecting surface 11a forming a concave curved surface of the first mirror 11 faces forward and downward of the vehicle.

As shown in FIGS. 3, 4 and 5, the first mirror 11 intersects display light L from the display unit 20 (see FIG. 2) at cross points CP1, CP2 and CP3 in the height direction of the vehicle 200. is reflected toward the second mirror 12 so as to The cross points CP1, CP2, and CP3 are located between the first mirror 11 and the second mirror 12 in the optical path of the display light L. As shown in FIG. The display light L converges from the first mirror 11 to the cross points CP1, CP2, CP3 and diverges from the cross points CP1, CP2, CP3 toward the second mirror 12. FIG. Although part of the display light L intersects at the cross points CP1, CP2, and CP3, the positions where the display light L is imaged do not necessarily match the positions of the cross points. In the head-up display device 100 of the present disclosure, the display light L is imaged at a position different from the cross point between the first mirror 11 and the second mirror 12 in the height direction.
A method of setting the positions of the cross points CP1, CP2 and CP3 will be described in detail later.

As shown in FIG. 2, the second mirror 12 is a concave mirror curved along the height and width directions of the vehicle. The second mirror 12 reflects the display light L reflected from the first mirror 11 toward the windshield 201 . The second mirror 12 reflects the display light L from the first mirror 11 toward the windshield 201 so as to expand it. A reflecting surface 12a forming a concave curved surface of the second mirror 12 faces the rear upper side of the vehicle. The second mirror 12 cooperates with the first mirror 11 to suppress distortion of the virtual image due to reflection on the windshield 201 .

Next, a method of setting the positions of the cross points CP1, CP2 and CP3 will be described with reference to FIGS. 3, 4 and 5. FIG.
The positions of the cross points CP1, CP2, and CP3 on the optical path of the display light L are adjusted by the radius of curvature of the reflecting surface 11a of the first mirror 11, the diffusion angle of the display light L emitted by the display section 20, and the like. For example, as the radius of curvature of the reflecting surface 11a of the first mirror 11 increases, the positions of the cross points CP1, CP2, and CP3 approach the reflecting surface 11a. Further, as the diffusion angle of the display light L emitted from the display unit 20 increases, the positions of the cross points CP1, CP2, and CP3 come closer to the reflecting surface 11a. The cross points CP1, CP2, and CP3 are provided closer to the first mirror 11 than the middle position between the first mirror 11 and the second mirror 12. FIG.

Specifically, the cross points CP1, CP2, and CP3 will be described.
As shown in FIG. 4, the cross point CP2 is a position where rays L2T and L2B of the display light L corresponding to the viewpoint EP2 positioned at the upper end of the visible region R in the height direction intersect when viewed in the width direction. The light ray L2T is a light ray corresponding to the upper end of the virtual image display area K, and the light ray L2B is a light ray corresponding to the lower end of the virtual image display area K. FIG.
As shown in FIG. 5, the cross point CP3 is a position where rays L3T and L3B of the display light L corresponding to the viewpoint EP3 positioned at the lower end of the visible region R in the height direction intersect when viewed in the width direction. The light ray L3T is a light ray corresponding to the upper end of the virtual image display area K, and the light ray L3B is a light ray corresponding to the lower end of the virtual image display area K. FIG.
As shown in FIG. 3, the cross point CP1 is a position where rays L1T and L1B of the display light L corresponding to the viewpoint EP1 located in the center of the visible region R in the height direction intersect when viewed in the width direction. A light ray L1T is a light ray corresponding to the upper end of the virtual image display area K, and a light ray L1B is a light ray corresponding to the lower end of the virtual image display area K. FIG.
Note that each of the viewpoints EP1, EP2, and EP3 is positioned at the center of the visible region R in the width direction of the vehicle.

The two light beams L1T, L1B, L2T, L2B, L3T, and L3B forming the cross points CP1, CP2, and CP3 intersect when viewed two-dimensionally from the width direction. However, in reality, the rays L1T, L1B, L2T, L2B, L3T, and L3B extend in a three-dimensional space and do not necessarily intersect at the cross points CP1, CP2, and CP3. Therefore, in this example, the cross points CP1, CP2, and CP3 are points of intersection obtained by projecting the light beams L1T, L1B, L2T, L2B, L3T, and L3B onto the plane PL on which the line segments of the light beams L2T and L3B all lie. Defined.

As shown in FIG. 6, the cross points CP1, CP2, and CP3 include part of the reflecting surface 11a of the first mirror 11 within an imaginary circle C whose diameter is a line segment connecting the two cross points CP2 and CP3. It is set in a position where A cross point CP1 is positioned at the center position of the virtual circle C. As shown in FIG. The virtual circle C is specified by experiment or simulation.

In the comparative example of FIG. 7, the cross points CP1, CP2, and CP3 are set at positions where the reflecting surface 11a of the first mirror 11 is not included in the virtual circle C. As shown in FIG. In this comparative example, the cross points CP1, CP2, and CP3 are farther from the reflecting surface 11a than in the present embodiment shown in FIG. In terms of optical path design, it is necessary to form the reflecting surface 11a at a position where the traveling direction of the display light L is reversed from the cross points CP2 and CP3 toward the reflecting surface 11a. need to be bigger. Therefore, the gap S2 between the upper end of the reflecting surface 11a of the first mirror 11 and the display light L reflected by the second mirror 12, especially the light ray L2T, becomes smaller. Therefore, in this comparative example, it is necessary to increase the size of the reflecting surface 11a, and various members such as a mirror holder (not shown) that holds the first mirror 11 may interfere with the optical path of the display light L.

On the other hand, in this embodiment of FIG. 6, the cross points CP1, CP2, and CP3 are closer to the reflecting surface 11a than in the comparative example of FIG. As a result, as shown in FIG. 6, the display light L, particularly the light ray L2T, does not reach the omissible region 11b of the reflecting surface 11a, and the display light L, particularly the light beam L2T, does not reach the omissible region 11c of the reflecting surface 11a. , the ray L3B does not reach. Therefore, the omissible areas 11b and 11c can be omitted from the reflecting surface 11a, and the size of the reflecting surface 11a can be reduced.
Further, the gap S1 between the upper end of the reflecting surface 11a of the first mirror 11 and the display light L reflected by the second mirror 12, especially the light ray L2T, becomes large. Therefore, various members such as a mirror holder (not shown) that holds the first mirror 11 can be prevented from interfering with the optical path of the display light L. FIG.

(effect)
According to the embodiment described above, the following effects are obtained.
(1) The head-up display device 100 projects the display light L onto the windshield 201, which is an example of the projected member, so that the viewer 1 whose viewpoints EP1, EP2, and EP3 are within the visible region R visually recognizes the virtual image V. make it possible. The head-up display device 100 includes a display unit 20 that emits display light L, a first mirror 11 that has a reflecting surface 11a that reflects the display light L emitted from the display unit 20, and the first mirror 11 that reflects the display light L. and a second mirror 12 that reflects the display light L toward the windshield 201 . The display light L intersects at a cross point CP2, which is an example of a first cross point, and a cross point CP3, which is an example of a second cross point, in the height direction, which is an example of a specific direction. A portion of the reflecting surface 11a of the first mirror 11 is included in a virtual circle C having a diameter D of a line segment connecting the cross points CP2 and CP3. The cross point CP2 is a point at which the display light L corresponding to the viewpoint EP2 at the first end (upper end) of the visible region R in the height direction intersects. The cross point CP3 is a point at which the display light L corresponding to the viewpoint EP3 at the second end (lower end) of the visible region R in the height direction intersects.
According to this configuration, a portion of the reflecting surface 11a of the first mirror 11 is included in the virtual circle C, so the cross point CP2 and the cross point CP3 are set near the reflecting surface 11a of the first mirror 11. FIG. For this reason, the size of the reflecting surface 11a can be reduced for the reason described above. As a result, the size of the head-up display device 100 can be reduced.
Also, various members such as a mirror holder (not shown) that holds the first mirror 11 can be prevented from interfering with the optical path of the display light L. FIG. This increases the degree of freedom in designing the head-up display device 100 .

(2) The cross point CP2 and the cross point CP3 are located between the first mirror 11 and the second mirror 12 in the optical path of the display light L.
With this configuration, the size of the head-up display device 100 can be reduced.

The present disclosure is not limited by the above embodiments and drawings. Changes (including deletion of components) can be made as appropriate without changing the gist of the present disclosure. An example of modification will be described below.

(Modification)
In the above embodiment, the cross points CP1, CP2, and CP3 are set between the first mirror 11 and the second mirror 12 in the optical path of the display light L. , may be set between the reflecting surface 11 a and the light emitting surface 21 . In this case, the light emitting surface 21 emits display light L that converges so as to intersect at cross points CP1, CP2, and CP3 before reaching the reflecting surface 11a. Even in this case, part of the reflective surface 11a of the first mirror 11 is included in the virtual circle C whose diameter is the line segment connecting the two cross points CP2 and CP3. Thereby, the same effects as those of the above-described embodiment can be obtained.

Although the display lights L intersect in the height direction of the vehicle 200 in the above embodiment, they may intersect in the width direction of the vehicle 200 instead of or in addition to this. In this case, the reflecting surface 11 a of the first mirror 11 is formed in a concave shape curved along the width direction of the vehicle 200 . In this modified example, too, at least part of the reflecting surface 11a is set to be included in the virtual circle specified by the cross points crossing in the width direction by the same method as in the above embodiment.

In the above embodiment, part of the reflective surface 11a of the first mirror 11 is included within the virtual circle C when viewed in the width direction. may be included.
Further, in the above-described embodiment, the positions of the cross points CP1, CP2, and CP3 are set so that a part of the reflecting surface 11a of the first mirror 11 is included in the virtual circle C, but from the same point of view, The positions of the cross points CP1, CP2, and CP3 may be set such that a portion of the reflecting surface 11a of the first mirror 11 is included in the virtual sphere containing the virtual circle C. FIG.

In the above-described embodiment, the second mirror 12 may be configured to be rotatable about a rotation axis along the width direction of the vehicle by the mirror driving section. By rotating the second mirror 12 around the rotation axis, it is possible to adjust the irradiation position of the display light L to the viewer 1 in the height direction. In this case, for example, the cross points CP1, CP2, and CP3 and the virtual circle C are specified at the rotation angle of the second mirror 12 at which the irradiation position of the display light L is the central position in the height direction.

In the above embodiment, the head-up display device 100 is mounted on a vehicle, but it is not limited to this, and may be mounted on a vehicle such as an airplane or a ship. Further, the projected member is not limited to the windshield 201, and may be a dedicated combiner.

1 viewer 11 first mirrors 11a, 12a reflecting surfaces 11b, 11c omissible area 12 second mirror 20 display unit 21 light emitting surface 30 case 100 head-up display device 200 vehicle 201 windshield C virtual circle D diameter K virtual image display area L display light R visible regions S1, S2 gap V virtual images L1B, L2B, L3B, L1T, L2T, L3T light rays CP1, CP2, CP3 crossing points EP1, EP2, EP3 viewpoint PL plane

Claims (3)

A head-up display device that allows a viewer whose viewpoint is within a visible region to visually recognize a virtual image by projecting display light onto a projected member,
a display unit that emits the display light;
a first mirror having a reflecting surface that reflects the display light emitted from the display unit;
a second mirror that reflects the display light reflected by the first mirror toward the projected member;
the display light intersects at a first cross point and a second cross point in a specific direction;
at least part of the reflecting surface of the first mirror is included in a virtual circle having a diameter of a line segment connecting the first cross point and the second cross point;
The first cross point is a point at which the display light corresponding to the viewpoint of the first end of the visible region in the specific direction intersects,
The second cross point is a point at which the display light corresponding to a viewpoint of a second end opposite to the first end of the visible region in the specific direction intersects.
Head-up display device. The first cross point and the second cross point are located between the first mirror and the second mirror in the optical path of the display light.
The head-up display device according to claim 1. The first cross point and the second cross point are positioned between the display unit and the first mirror in the optical path of the display light.
The head-up display device according to claim 1.

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