WO2020090187A1

WO2020090187A1 - Virtual-image display device and head-up display device

Info

Publication number: WO2020090187A1
Application number: PCT/JP2019/032057
Authority: WO
Inventors: 一能野口; シュレーダーハイコ
Original assignee: コニカミノルタ株式会社; フォルクスヴァーゲンアクチエンゲゼルシャフト
Priority date: 2018-10-29
Filing date: 2019-08-15
Publication date: 2020-05-07
Also published as: JPWO2020090187A1

Abstract

[Problem] To provide a virtual-image display device and a head-up display device capable of preventing or suppressing a change in virtual image distance when adjusting the position of an eyebox in the height direction. [Solution] This virtual-image display device has a display element 21, a virtual-image projection optical system 22, and a mirror rotation mechanism 25. The virtual-image projection optical system 22 is provided with a mirror 221 that reflects an image formed on the display surface 21a of the display element 21 and converts an image i1 formed on the display surface 21a into a virtual image i2. The mirror rotation mechanism 25 rotates the mirror 221. The mirror rotation mechanism 25 rotates the mirror 221 around a position lower than the center of the mirror 221 to adjust the position of an eyebox in the height direction.

Description

Virtual image display device and head-up display device

The present invention relates to a virtual image display device and a head-up display device.

A conventional head-up display (hereinafter, also simply referred to as “HUD”) generally generates a virtual image at a position separated from a driver by a certain distance. The contents displayed by the HUD include vehicle speed and car navigation. It was limited to information. In the first place, the purpose of mounting the HUD in a vehicle is to support safer driving by minimizing the movement of the driver's line of sight. In the sense of safe driving assistance, not only the display contents such as vehicle speed but also, for example, a vehicle or a pedestrian in front, obstacles, etc. are detected by a camera or a sensor, and the driver is made aware of the danger in advance through the HUD to prevent an accident. A system that prevents the occurrence is more preferable. In order to realize such a system, for example, it is conceivable to superimpose and display a danger signal as a virtual image on a see-through image that is a target for detecting a danger of a car, a person, an obstacle, or the like.

When displaying such a virtual image, the distance to the object (object) to be detected as a danger is not constant. For example, when a danger signal is displayed and superimposed on a virtual image that is visible 2 m away from a danger 50 m away, a difference in focus position occurs, which causes a problem that human eyes feel discomfort. As a method for solving such a problem, it is conceivable to superimpose a virtual image on the real object including the depth direction. Various techniques have been proposed as a method of giving a virtual image depth.

Also, since the height of the eyes of the driver sitting in the seat changes depending on the seat height of the driver, it is necessary to adjust the position of the eyebox in the height direction according to the seat height of the driver. In relation to this, a technique is known in which the position of the eye box in the height direction is adjusted by rotating the mirror of the HUD optical system (for example, Patent Document 1 below).

JP, 2017-26675, A

However, the technique of Patent Document 1 has a problem that the virtual image distance changes when the position of the eye box in the height direction is adjusted.

The present invention has been made in view of the above circumstances, and provides a virtual image display device and a head-up display device capable of preventing or suppressing a change in virtual image distance when adjusting the position of the eye box in the height direction. With the goal.

The above object of the present invention is achieved by the following means.

(1) A virtual image projection optical system that includes a display element and a mirror that reflects an image formed on the display surface of the display element, converts the image formed on the display surface to form a virtual image, and the mirror. A mirror rotation mechanism for rotating the mirror rotation mechanism, wherein the mirror rotation mechanism rotates the mirror about a position lower than the center of the mirror as a rotation center, thereby adjusting the position of the virtual image in the height direction. apparatus.

(2) The virtual image display device according to (1), wherein the rotation center is located at the lower end of the mirror.

(3) The virtual image display device according to (1), wherein the center of rotation is arranged at a position lower than the lower end of the mirror.

(4) The virtual image projection optical system further includes a combiner that displays the reflected light from the mirror as a virtual image, and the mirror is arranged immediately before the combiner along the optical path. The virtual image display device according to any one of (3).

(5) The virtual image display device according to any one of (1) to (4) above,
A head-up display device in which the position of a virtual image in the height direction is adjusted by the mirror rotation mechanism according to the sitting height of a driver.

(6) Further, a sitting height detecting section for detecting the sitting height of the driver is provided,
The head-up display device according to (5) above, wherein the position of the virtual image in the height direction is adjusted by the mirror rotation mechanism according to the seat height of the driver detected by the seat height detection unit.

According to the present invention, since the position of the eye box in the height direction is adjusted by rotating the mirror around the position lower than the center of the mirror of the virtual image projection optical system, the seat height of the driver can be adjusted. Accordingly, when adjusting the position of the eye box in the height direction, it is possible to prevent or suppress the change of the virtual image distance. Therefore, even when the object on which the virtual image is superimposed and displayed exists in the range from the distant to the vicinity, the deviation between the object and the virtual image visible from the driver's eye position is reduced, and a safer driving support system is provided. Can be realized.

It is a sectional view showing the state where the head up display device concerning this embodiment was carried in vehicles. It is the schematic diagram which looked at the vehicle carrying the head-up display device from the inside. It is a schematic diagram which shows the structure of a virtual image display apparatus. It is a block diagram which shows the hardware constitutions of a head-up display device. FIG. 11 is a schematic diagram for explaining a change in display position due to mirror tilt when the center of the mirror is the center of rotation as a comparative example. It is a schematic diagram for demonstrating tilt when the lower end of a mirror is made into a rotation center. It is a schematic diagram for demonstrating tilt when the lower end of a mirror is made into a rotation center. FIG. 9 is a schematic diagram for explaining a change in display position due to tilt when the lower end of the mirror is the rotation center. It is a schematic diagram which shows one modification of the structure which tilts a mirror.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. Also, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios. In the drawings, the horizontal direction of the eye box is the X direction, the vertical direction is the Y direction, and the direction perpendicular to the XY plane is the Z direction. Further, when the virtual image display device is mounted on the vehicle, the traveling direction of the vehicle is parallel to the Z direction.

FIG. 1 and FIG. 2 are schematic diagrams illustrating a usage state in which a virtual image display device 20 according to the present embodiment and a head-up display device 10 including the virtual image display device 20 are mounted inside a vehicle body 811 of a vehicle 800. The user (driver) 900 is sitting in the driver's seat 816 while gripping the steering wheel 813. As shown in FIGS. 1 and 2, the virtual image display device 20 of the head-up display device 10 displays the image information displayed on the display element 21 described later as a virtual image toward the user 900 via the display screen 220. To do.

The components other than the display screen 220 of the virtual image display device 20 are installed in the dashboard 814 of the vehicle body 811 so as to be embedded behind the display 815 such as a car navigation system. The virtual image display device 20 emits display light D1 corresponding to a virtual image including driving-related information and the like toward the display screen 220. The display screen 220 is also called a combiner, and is a semi-transparent concave mirror or a plane mirror. The display screen 220 is erected on the dashboard 814 by supporting the lower end thereof, and reflects the display light D1 from the virtual image display device 20 toward the rear side (Z direction) of the vehicle body 811. That is, in the illustrated case, the display screen 220 is an independent type installed separately from the front window 812. The display light D1 reflected by the display screen 220 is guided to the pupil 910 of the user 900 sitting in the driver's seat 816 and an eye box (Eyebox) (see FIG. 3) corresponding to the peripheral position thereof.

The eye box is a range in which the user 900 can visually recognize all virtual images formed on the display surface of the display element. The eye box of the user 900 sitting in the driver's seat 816 with the head-up display device 10 mounted on the vehicle 800. The position (height) of the pupil 910, that is, a predetermined range including the eye point EP is set. The range of the eye box is adjusted according to the sitting height of the user 900.

The user 900 can observe the display light D1 reflected by the display screen 220, that is, the virtual image i2 as a display image separated by a predetermined distance (virtual image distance) as if it were in front of the vehicle body 811. On the other hand, the user 900 can observe external light transmitted through the display screen 220, that is, a front view, a real image of an automobile or the like. As a result, the user 900 observes the virtual image i2 including the driving-related information and the like formed by the reflection of the display light D1 on the display screen 220 so as to be superimposed on the background image behind the display screen 220, that is, the see-through image. it can.

FIG. 3 is a schematic diagram showing the configuration of the virtual image display device 20. As shown in FIG. 3, the virtual image display device 20 includes a display element 21, a virtual image projection optical system 22, a mirror moving mechanism 25, a housing 26, and a display control unit 30. The components of the virtual image display device 20 other than the display screen 220 are housed in the housing 26.

The display element 21 has a two-dimensional display surface 21a. The image i1 formed on the display surface 21a is magnified by the virtual image projection optical system 22, converted into a virtual image and projected on the eye box. At this time, by using the display element 21 capable of two-dimensional display, the display content of the image i1 can be switched at a relatively high speed. As the display element 21, it is preferable to use a transmissive element such as liquid crystal.

The virtual image projection optical system 22 includes a display screen 220 and first and

second mirrors

221 and 222. The

mirrors

221 and 222 have a spherical surface, a parabolic surface, or a free-form surface, and have optical power. The mirror 221 can be, for example, a concave mirror. These optical elements are arranged in the order of the second mirror 222, the first mirror 221, and the display screen 220 along the optical axis AX (optical path). The image i1 formed on the display surface 21a of the display element 21 is sequentially reflected by these optical elements and guided to the eye box. Accordingly, the user 900 can observe the virtual image i2 as a display image that is separated by a predetermined distance (virtual image distance).

The mirror moving mechanism 25 includes a drive motor such as a stepping motor and an actuator, and moves the mirror 221 farther from the display element 21 on the optical axis AX (in the optical path) of the plurality of

mirrors

221 and 222. ..

The virtual image distance is set to a long distance by shifting the mirror 221 along the optical axis AX by the mirror moving mechanism 25 in the direction away from the display element 21. In addition, the virtual image distance is set to a short distance by shifting in the opposite direction.

Furthermore, in the present embodiment, the mirror moving mechanism 25 functions as a mirror rotating mechanism and can also tilt the mirror 221 (rotate and move around the X-axis direction). The rotation axis is not limited to around the X-axis direction, and any direction can be selected. By tilting the mirror 221 by the mirror moving mechanism 25, the direction of the optical axis AX is changed, and the position where the display light D1 from the mirror 221 is reflected on the display screen 220 moves. As a result, the direction of the display light D1 reflected by the display screen 220 is changed.

The display control unit 30 controls the mirror moving mechanism 25 and tilts the mirror 221 according to the sitting height of the user 900 to adjust the height of the virtual image i2 so that the user 900 can observe the virtual image i2. Adjust the height. The seat height adjustment may be configured to be performed according to an instruction from the user 900, or may be configured to be automatically performed by software when the user 900 sits on the seat.

Although the virtual image display device 20 includes the two

mirrors

221 and 222 in the present embodiment, the present invention is not limited to this, and the virtual image display device 20 may include only one mirror 221.

(Head-up display device 10)
FIG. 4 is a block diagram illustrating the hardware configuration of the head-up display device 10. The head-up display device 10 includes a driver detection unit 71, an environment monitoring unit 72, an operation speed acquisition unit 73, and a main control unit 60, in addition to the virtual image display device 20 described above. The main control unit 60 controls the entire head-up display device 10 to display a virtual image corresponding to an object such as an oncoming vehicle or a passerby at an appropriate virtual image distance.

The driver detection unit 71 is a unit that detects the presence and the viewpoint position of the user 900 in the vehicle 800, and includes an internal camera 71a facing the driver seat 816, a driver seat image processing unit 71b, and a determination unit 71c. .. The internal camera 71a is installed on the dashboard 814 inside the vehicle body 811 so as to face the driver's seat 816 (see FIG. 2), and captures images of the head of the user 900 sitting in the driver's seat 816 and its surroundings. To do. The image processing unit 71b performs various image processing such as brightness correction on the image captured by the internal camera 71a, and facilitates the processing by the determination unit 71c. The determination unit 71c detects the sitting height, that is, the height of the head or the eye (pupil 910) of the user 900 by extracting or cutting out an object from the driver seat image processed by the image processing unit 71b. Further, from the depth information attached to the driver's seat image, the presence or absence of the head of the user 900 in the vehicle body 811 and the spatial position of the pupil 910 of the user 900, that is, the eye point EP (as a result, the direction of the line of sight) are calculated. The driver detection unit 71 functions as a sitting height detection unit.

The environment monitoring unit 72 identifies an object such as a car, a bicycle, or a pedestrian approaching in the front and determines the distance to the object. The environment monitoring unit 72 includes an external camera 72a, an external image processing unit 72b, and a determination unit 72c. The external camera 72a is installed at appropriate places inside and outside the vehicle body 811, and captures an external image of the front or side of the user 900 or the vehicle 800. The image processing unit 72b performs various image processing such as brightness correction on the image captured by the external camera 72a, and facilitates the processing by the determination unit 72c. The determination unit 72c detects the presence or absence of an object such as a car, a bicycle, or a pedestrian by extracting or cutting out an object from the external image processed by the image processing unit 72b, and determines the vehicle from the depth information accompanying the external image. The spatial position of the object in front of 800 is calculated.

The internal camera 71a and the external camera 72a include, for example, a compound eye type three-dimensional camera. That is, each of the

cameras

71a and 72a is an array of camera elements including a lens for image formation, a CMOS (Complementary Metal-Oxide Semiconductor), and other image pickup elements arranged in a matrix. Drive circuits. The plurality of camera elements forming each of the

cameras

71a and 72a are configured to focus at different positions in the depth direction, or to detect relative parallax, and are obtained from each camera element. The distance to each area in the image or the object is determined by analyzing the state of the image (focus state, position of the object, etc.).

Further, in place of the compound-eye type external camera 72a, LIDAR (Light Detection And Ranging) technology may be used. This makes it possible to obtain distance information in the depth direction for each part (area or object) in the detection area. With the LIDAR technology, it is possible to measure scattered light with respect to pulsed laser irradiation, measure the distance and spread to an object at a long distance, and obtain distance information to the object in the field of view and information about the spread of the object. By combining the radar sensing technology such as the LIDAR technology and the technology for detecting the distance of the object from the image information, the detection accuracy of the object can be improved.

The operation speed acquisition unit 73 acquires operation speed data according to the number of tire rotations from the vehicle body. The operation speed acquisition unit 73 itself may include a GPS sensor, an acceleration sensor, a gyro sensor, etc. to detect the operation speed of the vehicle.

The display control unit 30 operates the virtual image display device 20 under the control of the main control unit 60 to display the virtual image i2 with a changed virtual image distance (also referred to as a projection distance) behind the display screen 220. The display control unit 30 generates the virtual image i2 to be displayed on the virtual image display device 20 from the display information including the display shape and the display distance (virtual image distance) received from the environment monitoring unit 72 via the main control unit 60. The virtual image i2 serves as a marker such as a rectangular frame located around the display screen 220 in the depth position direction with respect to an automobile, a bicycle, a pedestrian, or other objects behind the display screen 220. The display form of the virtual image may be a number indicating the speed according to the traveling speed data.

The display control unit 30 receives the detection output regarding the presence of the user 900, the position of the eyes, and the sitting height from the driver detection unit 71 via the main control unit 60. As a result, it is possible to automatically start or stop the projection of the virtual image i2 by the virtual image display device 20. Further, the virtual image i2 can be projected only in the direction of the line of sight of the user 900. Furthermore, it is also possible to perform projection in which only the virtual image i2 in the direction of the line of sight of the user 900 is brightened, flashed, or otherwise emphasized.

The main control unit 60 sends display information including display shape and virtual image distance setting to the display control unit 30 according to the operation speed data acquired by the operation speed acquisition unit 73. When the operating speed is high, medium, or low, the display information is sent to set the virtual image distance to long distance, medium distance, or short distance, respectively. For example, if the traveling speed is 50 km / h or more, the virtual image distance is set to 24 m, if it is 30 km / h or less, the virtual image distance is set to 4 m, and if it is an intermediate speed, the virtual image distance is set to 7 m.

As described above, in the head-up display device according to the present embodiment, by changing the virtual image distance according to the traveling speed of the vehicle equipped with the virtual image display device 20 or the position of the object, the line-of-sight movement of the user 900 (focusing) can be performed. It is possible to reduce the burden of adjustment.

(Principle of sitting height adjustment)
The seat height adjustment of the present embodiment will be described with reference to FIGS. 5 to 6B. FIG. 5 is a schematic diagram for explaining the change of the display position by tilt when the center of the mirror 221 is set as the rotation center as a comparative example. Further, FIGS. 6A and 6B are schematic diagrams for explaining the tilt when the lower end of the mirror 221 in the present embodiment is the rotation center. 6A and 6B, the components other than the mirror 221 are not shown.

As shown in FIG. 5, when the mirror moving mechanism 25 tilts the mirror 221, the direction of the optical axis AX is changed. For example, a case will be described in which the mirror 221 is initially arranged at the reference position M0 and then rotates about the center (center of gravity) C0 of the mirror 221 as the rotation center. The optical axis when the mirror 221 is arranged at M0 is AX0, and the center position in the Y direction when the light reflected by the display screen 220 reaches the pupil 910 of the user 900 (hereinafter, referred to as “display position”). Be Y0.

When the mirror 221 is tilted clockwise by a predetermined angle φ1 and is moved from M0 to M1, the optical axis is changed to AX1 and light is reflected on the display screen 220 near the user 900, so that the display position is It will be Y1. On the other hand, when the mirror 221 is tilted counterclockwise by a predetermined angle φ2 and moved from M0 to M2, the optical axis is changed to AX2, and light is reflected on the display screen 220 on the side far from the user 900. The display position is Y2.

By tilting the mirror 221, the display position is changed according to the rotation direction and the rotation angle of the mirror 221. Therefore, when the height of the pupil 910 of the user 900, that is, when the eye point EP is higher or lower than Y0, the display position can be adjusted to a desired height by tilting the mirror 221. Since the eyepoint EP is considered to be proportional to the seat height of the user 900, adjusting the display position to a desired height will be referred to as “sitting height adjustment” in the present specification.

However, as described above, when the sitting height is adjusted by tilting the mirror 221 with the center C0 of the mirror 221 as the center of rotation, the optical path length of the optical axis AX changes. More specifically, when the mirror 221 is tilted clockwise by φ1, the optical path length L1 of the optical axis AX1 becomes longer than the optical path length L0 of the optical axis AX0. On the other hand, when the mirror 221 is tilted counterclockwise by φ2, the optical path length L2 of the optical axis AX2 becomes shorter than the optical path length L0 of the optical axis AX0. The optical path length L of the optical axis AX is related to the magnification m of the virtual image i2, and the magnification m increases as the optical path length L extends. That is, the fact that the optical path length of the optical axis AX changes when the seat height is adjusted means that the virtual image distance changes when the seat height is adjusted. Therefore, it is preferable to minimize the change in the optical path length L in the sitting height adjustment.

Therefore, in the present embodiment, the mirror moving mechanism 25 tilts the mirror 221 around the position lower than the center C0 of the mirror 221 as the rotation center, so that the image i1 is displayed toward the eyepoint EP of the user 900. Adjust to. More specifically, it is as follows.

For example, as shown in FIG. 6A, the mirror moving mechanism 25 tilts the mirror 221 with the lower end C1 of the mirror 221 (indicated by “●”) as the center of rotation. The mirror 221 is tilted clockwise by θ1 and moved from M0 to M3. When θ1 is equal to φ1, M3 is arranged in the same direction as M1 in FIG. 5 and shifted by a distance S1 from M0 in the positive Y and Z directions. The distance S1 corresponds to the shift component of the movement due to the tilt of the mirror 221.

Also, as shown in FIG. 6B, the mirror 221 is tilted counterclockwise by θ2 and moved from M0 to M4. When θ2 is equal to φ2, M4 is arranged in the same direction as M2 in FIG. 5, but shifted in the negative Y and Z directions by a distance S2 from M2. The distance S2 corresponds to the shift component of the movement due to the tilt of the mirror 221.

As shown in FIG. 7, when the lower end C1 of the mirror 221 is tilted about the rotation center, the shift components (S1 and S2) make the optical path length longer than when tilted about the center C0 of the mirror 221 in FIG. 5 about the rotation center. L0 does not change, but the optical path length L1 becomes shorter and L2 becomes longer.

Therefore, when tilting with the lower end C1 of the mirror 221 as the center of rotation, the difference between the optical path lengths L1 and L0 and the difference between L2 and L0 are smaller than when tilting with the center C0 of the mirror 221 as the center of rotation. Become.

Note that when the rotation center is the lower end C1 of the mirror 221, the movable range of the mirror 221 is wider than in the case of the center C0 of the mirror 221, but the volume of the virtual image display device 20 can be prevented from significantly increasing. Further, the rotation center is not limited to the case where the lower end C1 of the mirror 221 is set, and the rotation center can be set at a position between the center C0 of the mirror 221 and the lower end C1.

(Example)
In the present embodiment, adjustment is possible in three levels of "standard" for users with standard sitting height and "low" and "high" for users with lower and higher sitting heights. When "high" is set by sitting height adjustment, the display position or the center of the eye box is raised by H1 = 25 [mm] in the Y direction. On the other hand, when the seat height is set to “low”, the display position or the center of the eye box is lowered by H2 = 25 [mm] in the Y direction.

[Table 1] below is an example of the result of calculation by simulation of the virtual image distance on the far side when the rotation center position is the upper end, the center, and the lower end of the mirror 221. As described above, the virtual image distance on the far side set according to the traveling speed is 24 [m] (hereinafter, referred to as “set value”).

As shown in Table 1, when the sitting height is standard +25 [mm], the virtual image distance is set when the lower end of the mirror 221 is the center of rotation, compared to when the upper end or center of the mirror 221 is the center of rotation. It was close to the value.

Even when the seat height is standard -25 [mm], the virtual image distance is closer to the set value when the lower end of the mirror 221 is the rotation center than when the upper end or the center of the mirror 221 is the rotation center. It became a value.

Note that in Table 1, the difference ΔDPT between the diopter (DPT) between the set value and the calculated value is also shown in parentheses. For example, when the sitting height is standard +25 [mm] and the upper end of the mirror 221 is the center of rotation, ΔDPT = ABS (1 / 24-1 / 135.0) ≈0.034. Here, ABS (...) Represents the absolute value of (...).

In addition, although the calculation result is not shown in Table 1, the look-down angle is irrespective of the position of the rotation center of the mirror 221 regardless of whether the seat height is standard +25 [mm] or standard -25 [mm]. , And the values were almost constant. The looking down angle is an angle with respect to a horizontal line of a line connecting the center of the pupil 910 of the user 900 and the center of the virtual image i2.

(Modification)
FIG. 8 is a schematic diagram showing a modified example of the configuration in which the mirror 221 is tilted. In this modification, the rotation center of the mirror 221 is set at a position lower than the lower end C1 of the mirror 221.

The virtual image display device 20 has, for example, a support member 223 that supports the lower end C1 of the mirror 221. The support member 223 is a rod-shaped member, one end of which is connected to the lower end C1 of the mirror 221, and the other end C2 of which extends to the rotation center of the mirror 221. The support member 223 may be configured to support a portion other than the lower end C1 of the mirror 221.

By setting the center of rotation at a position lower than the lower end C1 of the mirror 221, the shift component of the movement due to the tilt of the mirror 221 increases. Therefore, the change in the virtual image distance when adjusting the sitting height can be further reduced. For example, the center of rotation may be a position on an extension line extending downward from the lower end C1 along the shape of the mirror 221. Alternatively, the rotation center may be a position on an extension line extending downward from the lower end C1 along a straight line connecting the center C0 of the mirror 221 and the lower end C1.

Note that, by setting the rotation center of the mirror 221 at a position lower than the lower end C1 of the mirror 221, the movable range of the mirror 221 is expanded, so that the volume of the virtual image display device 20 can be increased. When the increase in the volume of the virtual image display device 20 is within the allowable range, theoretically, the change in the virtual image distance at the time of adjusting the seat height is zero, that is, the virtual image distance can be made as close as possible to the set value.

In the present modification, the distance between C1 and C2 is equal to the distance between C0 and C1 in consideration of the increase in volume of the virtual image display device 20 and the influence of vibration accompanying the increase in the distance between the rotation center and the mirror 221. The length can be set to be approximately the same as the distance between C0 and C1 from the half length.

The virtual image display device and the head-up display device of the present embodiment described above have the following effects.

The position in the height direction of the eye box is adjusted by rotating the mirror 221 with the positions C1 and C2 lower than the center C0 of the mirror 221 as the center of rotation. Therefore, according to the sitting height of the user 900, It is possible to prevent or suppress the change of the virtual image distance when adjusting the position of. Therefore, even when the object on which the virtual image is superimposed and displayed exists in the range from the distant to the vicinity, the difference between the object and the virtual image that can be seen from the position of the eye of the user 900 is reduced, and a safer driving support system is provided. Can be realized.

The virtual image display device described above, and the configuration of the head-up display device, the main configuration has been described in describing the features of the above embodiment, not limited to the above configuration, within the scope of the claims, Various modifications can be made. Further, the configurations included in a general virtual image display device and a head-up display device are not excluded.

For example, in the above-described embodiment, an example in which the virtual image distance is changed in three stages is shown, but the invention is not limited to this, and the virtual image distance may be changed in four or more stages. Similarly, in the above-described embodiment, the height of the virtual image is changed in three steps as the seat height adjustment, but the seat height may be adjusted in four or more steps.

This application is based on Japanese Patent Application No. 2018-203123 filed on Oct. 29, 2018, the disclosure content of which is incorporated by reference in its entirety.

10 head-up display device 20 virtual image display device 21 display element 21a display surface 22 virtual image projection optical system 220

display screen

221, 222 mirror 223 support member 26 housing 30 display control unit 60 main control unit 71 driver detection unit 72 environment monitoring unit 73 Operation speed acquisition unit 800 Vehicle 811 Body 812 Front window 813 Steering wheel 814 Dashboard 815 Display 816 Driver's seat 900 User 910 Eyes AX, AX1, AX2 Optical axis D1 Display light EP Eyepoint i1 image i2 Virtual image L, L1, L2 Optical path length

Claims

A display element,
A virtual image projection optical system that includes a mirror that reflects an image formed on the display surface of the display element, converts the image formed on the display surface, and forms a virtual image;
A mirror rotation mechanism for rotating the mirror,
The virtual image display device, wherein the mirror rotating mechanism adjusts the position of the virtual image in the height direction by rotating the mirror around a position lower than the center of the mirror as a rotation center.
The virtual image display device according to claim 1, wherein the rotation center is arranged at a lower end of the mirror.
The virtual image display device according to claim 1, wherein the rotation center is arranged at a position lower than a lower end of the mirror.
The virtual image projection optical system further includes a combiner that displays reflected light from the mirror as a virtual image, and the mirror is arranged immediately before the combiner along an optical path. The virtual image display device according to item 1.
A virtual image display device according to any one of claims 1 to 4,
A head-up display device in which the position of a virtual image in the height direction is adjusted by the mirror rotation mechanism according to the sitting height of a driver.
Furthermore, it has a sitting height detection unit that detects the sitting height of the driver,
The head-up display device according to claim 5, wherein the position of the virtual image in the height direction is adjusted by the mirror rotation mechanism according to the seat height of the driver detected by the seat height detection unit.