WO2018199246A1

WO2018199246A1 - Virtual image display device, and display system for moving body

Info

Publication number: WO2018199246A1
Application number: PCT/JP2018/017020
Authority: WO
Inventors: 野村英司; 山田範秀
Original assignee: コニカミノルタ株式会社
Priority date: 2017-04-28
Filing date: 2018-04-26
Publication date: 2018-11-01
Also published as: JPWO2018199246A1

Abstract

Provided is a virtual image display device which, despite having a simple configuration, is capable of displaying additional information such as a danger signal superimposed on an object such that the additional information can be appropriately recognized. This virtual image display device 100 is provided with: an image forming element 11 which is a rendering device; a main body optical system 13 which is an expansion/projection optical system which expands an image of the image forming element 11; and a display screen 20. The virtual image display device is further provided with: an arrangement changing device 62 which changes the projection distance by moving the image forming element 11 in the optical axis AX direction; and a display control unit 18 which causes a plurality of display images (virtual images) IM having different projection distances to be displayed, by causing the image forming element 11 and the arrangement changing device 62 to operate in conjunction with each other.

Description

Virtual image display device and moving body display system

The present invention relates to a virtual image display device that displays a virtual image at the end of a line of sight and a display system for a moving body equipped with the virtual image display device.

Conventional head-up display (HUD (Head-Up Display)) devices generally generate a virtual image at a certain distance from the driver, and the display contents by HUD are vehicle speed, car navigation. It was limited to information. In the first place, the purpose of installing the HUD in the car is to support the safer driving by minimizing the movement of the driver's line of sight. It is more preferable, for example, to detect a car, a pedestrian, an obstacle, etc. in front of the vehicle with a camera or a sensor, etc., and to let the driver detect the danger in advance through HUD to prevent an accident. . In order to realize such a system, for example, it is conceivable to display a danger signal or other additional information superimposed on a see-through image (target object) such as a car, a person, or an obstacle.

In the system that displays the danger signal as described above, if the distance from the driver to the virtual image is constant, the position of the real object (object) and the danger signal (virtual image) when the driver's eye position shifts ) Is misaligned, and the driver misidentifies the danger signal (that is, misidentifies the position of the object). As a technique for solving such a problem, it is conceivable to superimpose a virtual image on the real object (object) including the depth direction.

For example, in Patent Document 1, there is a method of changing the position of a virtual image by a scanning image forming means such as a MEMS (Micro Electro Mechanical Systems) mirror, a screen, a projection means, and a movable means for changing the position of the screen. It is disclosed. However, the main purpose of Patent Document 1 is to reduce the movement of the driver's line of sight by moving the virtual image position closer to or away from the vehicle according to the speed of the vehicle. The danger signal and the object are superimposed and displayed. It is not intended. Moreover, since the technique described in Patent Document 1 is not based on the above superimposed display, it is not related to the positional deviation between the danger signal and the target object.

JP 2009-150947 A

The present invention has been made in view of the above-described background art, and has a simple configuration and can display a virtual image display device that can superimpose and display additional information as described above on an object to the extent that appropriate recognition is possible. The purpose is to provide.

Another object of the present invention is to provide a moving body display system equipped with the virtual image display device.

In order to achieve at least one of the above-described objects, a virtual image display device reflecting one aspect of the present invention includes a drawing device, an enlarged projection optical system that enlarges an image of the drawing device, and a display screen. A display device that displays a plurality of virtual images with different projection distances by linking the arrangement changing device that changes the projection distance by moving the drawing device in the optical axis direction, and the drawing device and the arrangement changing device. A control unit. Here, the optical axis passes through the center of the drawing device, the center of the eye box, and the image point (virtual image) corresponding to the center of the drawing device created by the virtual image display device.

In order to realize at least one of the above-described objects, a moving body display system reflecting one aspect of the present invention includes a virtual image display device, an environment monitoring unit that detects a spatial position of an object, and the like. .

FIG. 1A is a side cross-sectional view showing a state in which the virtual image display device of the embodiment is mounted on a vehicle body, and FIG. 1B is a front view from the inside of the vehicle illustrating the virtual image display device. It is a figure explaining the specific optical system which comprises a virtual image display apparatus. It is a notional enlarged side sectional view explaining the example of concrete composition of a virtual image display. It is a figure for demonstrating the relationship between the position of an image formation element, and a virtual image position. 5A and 5B are diagrams illustrating the positional relationship between a virtual image position and an object by the virtual image display device of the embodiment. 6A and 6B are diagrams for explaining the positional relationship between a virtual image position and an object by a virtual image display device of a comparative example. It is a block diagram explaining the display system for moving bodies containing a virtual image display apparatus. It is a flowchart explaining operation | movement of the display system for moving bodies.

Hereinafter, an embodiment of a display system for a moving body of a virtual image display device according to the present invention will be described with reference to the drawings.

1A and 1B are a conceptual side sectional view and a front view illustrating a virtual image display device 100 according to the present embodiment and a use state thereof. The virtual image display device 100 is mounted in the vehicle body 2 as a head-up display device, for example, and includes a drawing unit 10 and a display screen 20. The virtual image display device 100 displays image information displayed on an image forming element 11 (to be described later) in the drawing unit 10 for a driver (observer) UN through a display screen 20.

The drawing unit 10 of the virtual image display device 100 is installed so as to be embedded in the dashboard 4 of the vehicle body 2, and directs display light HK corresponding to an image including driving-related information and a danger signal toward the display screen 20. Eject. The display screen 20 is a half mirror also called a combiner, and is a concave mirror or a plane mirror having a semi-transmission property. The display screen 20 is erected on the dashboard 4 with the lower end supported, and reflects the display light HK from the drawing unit 10 toward the rear of the vehicle body 2. That is, in the illustrated case, the display screen 20 is an independent type that is installed separately from the windshield (windshield) 8. The display light HK reflected by the display screen 20 which is a half mirror is guided to an eye box (not shown) corresponding to the pupil HT of the driver UN sitting in the driver's seat 6 and its peripheral position. As shown in FIGS. 1A and 2, the driver UN can observe the display light HK reflected by the display screen 20, that is, the display image IM as a virtual image in front of the vehicle body 2. On the other hand, the driver UN can observe the external light transmitted through the display screen 20 that is a half mirror, that is, a real image of a front view, a car, and the like. As a result, the driver UN overlaps the external image behind the display screen 20 and displays a display image (virtual image) IM including driving-related information, a danger signal, and the like formed by reflection of the display light HK on the display screen 20. Can be observed.

As shown in FIG. 3, the drawing unit 10 includes a main body optical system 13, a display control unit 18 that operates the main body optical system 13, and a housing 14 that houses the main body optical system 13 and the like. Among these, the combination of the main body optical system 13 and the display screen (combiner) 20 constitutes a virtual image display optical system 30. In FIG. 3 and the like, the coordinate axes XYZ have the origin of the center of the eye box corresponding to the position between the pupils HT of a general driver UN, but are displayed with the origin shifted for convenience.

The main body optical system (projection optical system) 13 includes an image forming element 11 and a virtual image forming optical system 17 that converts an image formed on the image forming element 11 into a virtual image.

The image forming element 11 is a drawing device (display unit) having a two-dimensional display surface 11a. The image formed on the display surface 11a of the image forming element 11 is guided to the virtual image forming optical system 17 and the like. At this time, the display image (virtual image) IM can be switched at a relatively high speed by using the image forming element 11 capable of two-dimensional display. The image forming element 11 includes a liquid crystal display panel (or a liquid crystal display (LCD)), a display driving circuit that causes the liquid crystal display panel to perform a display operation, and an LED that emits light for illuminating the liquid crystal display panel ( light emitting diode) Other light sources and a homogenizing optical system for uniformizing the light from such light sources. By using a liquid crystal display as a drawing device, the apparatus can be miniaturized. Further, since the light distribution angle of the LCD is wide, the viewing angle can be widened. The image forming element 11 operates at a frame rate of, for example, 60 fps or higher, preferably 240 fps, and more preferably 1000 fps. This makes it easy to make it appear as if a plurality of display images IM are simultaneously displayed at different projection distances.

The image forming element 11 is driven by the arrangement changing device 62 and moves along the optical axis AX at a constant speed or a periodic motion, for example. By moving the image forming element 11 along the optical axis AX by the arrangement changing device 62, the virtual image forming optical system 17 displays the display image IM as a virtual image formed behind the display screen (combiner) 20 and an observer. The distance to the driver UN can be increased or decreased. In this way, the position of the projected display image IM is changed back and forth, and the display content is made to correspond to the position, so that the display image IM is changed while changing the virtual image distance or the projection distance to the display image IM. The display image IM as a series of projection images can be made three-dimensional. Here, the optical axis AX is an image point (corresponding to the center of the image forming element 11 that is a drawing device, the center of the eye box, and the center of the image forming element (drawing device) 11 formed by the virtual image display device 100. Virtual image). The amount of movement of the image forming element 11 in the optical axis AX direction is 20 mm or less. Thereby, the image forming element 11 can be moved efficiently, the responsiveness of the image forming element 11 can be improved, and the volume of the virtual image display device 100 can be reduced. Further, the arrangement changing device 62 reciprocates the image forming element 11 at a speed of, for example, 15 Hz or more. In this case, since the speed exceeds the perception of the observer (driver UN), the observer can recognize virtual images with different projection distances almost simultaneously.

The image forming element 11 is supported by the support member 62a. The support member 62a is attached to the base 62b of the arrangement changing device 62 so as to be movable within a predetermined range along the optical axis AX direction. As shown in FIG. 4, at the timing when the image forming element 11 is arranged on the most upstream side of the moving range, the image displayed on the image forming element 11 at this time is a display screen (combiner) 20 that is a half mirror. It is displayed as a virtual image in the farthest behind. Further, at the timing when the image forming element 11 is arranged on the most downstream side of the moving range, the image displayed on the image forming element 11 at this time is closest to the back of the display screen (combiner) 20 that is a half mirror. Displayed as a virtual image. In the example of FIG. 4, the position (LCD position T1) of the image forming element 11 at the timing when the image forming element 11 is arranged on the most upstream side of the moving range is along the optical axis AX direction when the virtual image distance is 10 m. This is a position having a distance of 8.1 mm in a direction relatively away from the first mirror 17a described later. The position (LCD position T2) of the image forming element 11 at the timing when the image forming element 11 is arranged on the most downstream side of the moving range is the first along the optical axis AX direction when the virtual image distance is 3.5 m. This is a position having a distance of 7.7 mm in a direction relatively approaching the mirror 17a. Further, an LCD position T3 intermediate between the LCD positions T1 and T2 is a case where the virtual image distance is 5 m.

The virtual image forming optical system 17 is an enlargement projection optical system that expands an image formed on the image forming element 11 in cooperation with the display screen 20, and forms a display image IM as a virtual image in front of the driver UN. The virtual image forming optical system 17 includes at least one mirror, but in the illustrated example, includes two first and

second mirrors

17a and 17b. Here, the first mirror 17a is a first reflector and is disposed on the image forming element 11 side in the preceding stage of the optical path and has optical power. The second mirror 17b is disposed on the display screen (combiner) 20 side in the latter stage of the optical path and has optical power. The first and

second mirrors

17a and 17b can be convex surfaces, concave surfaces, or flat surfaces. In the case of curved surfaces, the first and

second mirrors

17a and 17b are not limited to spherical surfaces but can be aspherical surfaces, free curved surfaces, or the like.

The housing 14 has an opening 14a for allowing the display light HK to pass therethrough, and a film or a thin plate-like light transmitting member 14b can be disposed in the opening 14a.

FIG. 5A is a conceptual plan view for explaining display by the virtual image display optical system 30 or the virtual image display device 100 of the embodiment, and FIG. 5B is a diagram for explaining how the display corresponding to FIG. 5A is seen. As shown in FIG. 5A, a case will be described in which a display frame HW that is a display image IM is formed at or near the position of an object (in this case, a car traveling in an oncoming lane) KT that is being observed by the driver UN. . Such a display frame HW is a danger warning signal or other virtual image, and shows, for example, a result of identifying a car, a bicycle, a pedestrian, or the like that is close to the front. In this case, since the display frame HW projects the display frame HW in the vicinity of the object KT as shown in FIG. 5A, not only the driver UN at the standard position P0 but also the head as shown in FIG. 5B. Even for the driver UN whose posture has been changed to the change position P1 that has moved the position of the object KT, the object KT and the display frame HW are substantially overlapped and appear to be substantially free of deviation.

FIG. 6A is a conceptual plan view for explaining the display by the virtual image display optical system or the virtual image display device of the comparative example, and FIG. 6B is a diagram for explaining the appearance of the display corresponding to FIG. 6A. As shown in FIG. 6A, the case where the display frame HW, which is the display image IM, is formed at a fixed position regardless of the object KT that the driver UN is observing will be described. In this case, as shown in FIG. 6A, the display frame HW is projected substantially in front of the object KT. Therefore, as shown in FIG. 6B, for the driver UN at the standard position P0, the object KT and the display frame HW are displayed. The display frame HW appears to be greatly displaced in the lateral direction in which the eyes are aligned with respect to the object KT for the driver UN who has changed his / her posture to the change position P1. This increases the possibility of misidentifying the display frame HW.

FIG. 7 is a block diagram illustrating the moving body display system 200. The moving body display system 200 includes the virtual image display device 100 as a part thereof. The virtual image display device 100 has the structure shown in FIG. 3, and a description thereof is omitted here. A moving body display system 200 shown in FIG. 7 is incorporated in an automobile or the like that is a moving body.

The moving body display system 200 includes a driver detection unit 71, an environment monitoring unit 72, and a main control device 90 in addition to the virtual image display device 100.

The driver detection unit 71 is a part that detects the presence of the driver UN and the viewpoint position, and includes a driver seat camera 71a, a driver seat image processing unit 71b, and a driver seat image determination unit 71c. The driver's seat camera 71a is installed in front of the driver's seat of the dashboard 4 in the vehicle body 2 (see FIG. 1B), and takes an image of the head of the driver UN and its surroundings. The driver seat image processing unit 71b performs various types of image processing such as brightness correction on the image captured by the driver seat camera 71a to facilitate processing in the driver seat image determination unit 71c. The driver seat image determination unit 71c detects the head and eyes of the driver UN by extracting or cutting out an object from the driver seat image that has passed through the driver seat image processing unit 71b, and accompanies the driver seat image. The spatial position of the eyes of the driver UN is calculated along with the presence / absence of the head of the driver UN in the vehicle body 2 from the depth information.

The environment monitoring unit 72 is a part for identifying a car, a bicycle, a pedestrian, and the like that are close to the front, and includes an external camera 72a, an external image processing unit 72b, and an external image determination unit 72c. The external camera 72a is installed at appropriate positions inside and outside the vehicle body 2, and captures external images of the driver UN or the front windshield 8, such as the front and sides. The external image processing unit 72b performs various types of image processing such as brightness correction on the image captured by the external camera 72a to facilitate processing by the external image determination unit 72c. The external image determination unit 72c detects the presence or absence of an object KT (for example, see FIG. 5A) such as an automobile, a bicycle, or a pedestrian by extracting or cutting out the object from the external image that has passed through the external image processing unit 72b. At the same time, the spatial position of the object KT in front of the vehicle body 2 is calculated from the depth information attached to the external image. Here, the spatial position of the object KT includes the position in the depth direction in addition to the position in the plane corresponding to the visual field.

The driver's seat camera 71a and the external camera 72a are not shown, but are, for example, compound eye type three-dimensional cameras. In other words, both

cameras

71a and 72a are configured by arranging camera elements, which are a set of imaging lenses, CMOS (Complementary Metal Oxide Semiconductor) and other image sensors, in a matrix, and drive for the image sensors. Each has a circuit. The plurality of camera elements constituting each of the

cameras

71a and 72a are adapted to focus at different positions in the depth direction, for example, or to detect relative parallax, and are obtained from each camera element. By analyzing the state of the image (focus state, position of the object, etc.), it is possible to determine the distance to each region or object in the image.

Depth direction with respect to each part in the captured screen (dead angle image) even if a combination of a two-dimensional camera and an infrared distance sensor or a laser sensor is used instead of the compound-

eye cameras

71a and 72a as described above. Distance information can be obtained. In addition, distance information in the depth direction can be obtained for each part (region or object) in the captured screen by using a stereo camera in which two two-dimensional cameras are separately arranged instead of the compound-

eye cameras

71a and 72a. In addition, in a single two-dimensional camera, distance information in the depth direction can be obtained for each part in the captured screen by performing imaging while changing the focal length at high speed.

The display control unit 18 operates the virtual image display optical system 30 under the control of the main controller 90, and the three-dimensional display in which the virtual image distance or the projection distance changes behind the display screen (combiner) 20 that is a half mirror. The image IM is displayed. That is, the display control unit 18 displays a plurality of display images (virtual images) IM by interlocking the image forming element 11 and the arrangement changing device 62. The display control unit 18 generates a display image IM to be displayed on the virtual image display optical system 30 from display information including the display shape, display distance, or position information received from the environment monitoring unit 72 via the main control device 90. The display image IM is, for example, a display frame HW (FIG. 5B) located in the periphery with respect to the depth position direction and the direction orthogonal to the object KT such as an automobile, bicycle, pedestrian or the like existing behind the display screen 20. For example). The display control unit 18 receives the position information of the object KT from the environment monitoring unit 72 and displays a display image (virtual image) IM according to the position in the screen of the object KT corresponding to the display screen 20. Accordingly, the position of the display image (virtual image) IM can be made to correspond to the position of the object KT regardless of the viewpoint of the driver UN. Further, the display control unit 18 receives the position information of the object KT from the environment monitoring unit 72 under the control of the main controller 90, and adjusts the projection distance according to the spatial position of the object KT. . Thereby, even if the viewpoint of the driver UN shifts, it can be prevented that the position of the display image (virtual image) IM shifts from the position of the object KT that changes. The display control unit 18 causes the image forming element 11 to display an image in synchronization with the movement of the image forming element 11 by the arrangement changing device 62. Thereby, the display content of each virtual image having a different projection distance can be changed, and an image corresponding to the object KT that may exist at each position can be displayed.

The display control unit 18 receives a detection output regarding the presence of the driver UN and the position of the eyes from the driver detection unit 71 via the main control device 90. Thereby, the projection of the display image IM by the virtual image display optical system 30 can be automatically started and stopped. Further, it is possible to perform projection with emphasis such as brightening only the display image IM or blinking according to the spatial position of the eyes of the driver UN.

The main controller 90 has a role of coordinating the operations of the virtual image display device 100, the environment monitoring unit 72, and the like, and the virtual image display optics so as to correspond to the spatial position of the object KT detected by the environment monitoring unit 72. The spatial arrangement of the display frame HW projected by the system 30 is adjusted.

Hereinafter, the operations of the virtual image display device and the moving object display system will be described with reference to FIG. The operation of the display control unit 18 and the arrangement changing device 62 is started by receiving, for example, a detection output related to the eye position of the driver UN in the driver detection unit 71.

First, the virtual image display device 100 is initialized (step S11). Specifically, the arrangement changing device 62 is operated under the control of the main control device 90 to move the position of the image forming element 11 to the initial position. As already described, the image forming element 11 can move within a predetermined range along the optical axis AX direction, and for example, the most upstream side of the range from the most downstream side to the most upstream side of the moving range. The position is the initial position. In addition, the timing for displaying an image on the image forming element 11 in a certain period with the initial position as a reference is synchronized with the operation timing of the arrangement changing device 62.

Next, the object KT is searched (step S12). Specifically, the environment monitoring unit 72 is operated under the control of the main control device 90 to detect the presence or absence of the object KT.

Next, the object KT in the display area (or screen) of the display screen 20 is detected (step S13). Specifically, under the control of the main controller 90, the environment monitoring unit 72 is operated to detect the spatial position (XYZ coordinate position) of the object KT.

Next, the timing for displaying an image on the image forming element 11 and the display position of the virtual image are determined from the spatial position of the object KT, particularly the distance from the pupil HT of the driver UN to the object KT (step S14). . Specifically, in main controller 90, the timing for displaying an image and the display position of the virtual image are determined from the position data of object KT calculated by environment monitoring unit 72. The timing is related to the Z direction, and the display position is related to the XY direction. That is, the timing at which an image such as the display frame HW is displayed on the image forming element 11 is determined depending on the distance at which the object KT is present.

Next, based on the timing and position information determined in step S14, an image is displayed on the image forming element 11 (step S15). Specifically, the display control unit 18 is operated under the control of the main controller 90 to display a predetermined image on the image forming element 11 at a predetermined timing. At this time, the display control unit 18 causes the image forming element 11 to display an image in synchronization with the movement of the image forming element 11 by the arrangement changing device 62 under the control of the main control device 90. For example, a display frame HW can be displayed as a display image (virtual image) IM corresponding to a plurality of objects KT within the screen corresponding to the display screen 20.

After Step S15, when the operation of the mobile object display system is continued (Yes in Step S16), the process returns to Step S12.

In the virtual image display device and the moving body display system described above, the driver (observer) UN obtains three display images (virtual images) IM by linking the image forming element 11 and the arrangement changing device 62 which are drawing devices. A plurality of display images (virtual images) IM having different projection distances can be displayed so that they can be recognized dimensionally. By moving the image forming element 11 in the direction of the optical axis AX, the display image (virtual image) IM can be superimposed on the object KT including the depth direction. Thereby, even when the target object KT exists in the range from a distant place to the vicinity, the deviation between the target object KT and the display image (virtual image) IM due to the position of the eyes of the observer (driver UN) is reduced, so that it is safer. A simple driving support system can be realized. Therefore, even if the driver's viewpoint is deviated, the positional relationship between the display image (virtual image) IM such as a danger signal and the real object (the object KT) is not deviated, and thus misidentification of the driver UN can be prevented.

〔Example〕
Hereinafter, specific examples of the head-up display device according to the present invention will be described.
In the data of the examples shown below, Si (i = 0, 1, 2, 3,...) Is the i-th surface (the virtual image plane of the display image IM is counted from the virtual image plane side forming the display image IM. 0 side). The first and second surfaces S1, S2 following the 0th surface S0 corresponding to the virtual image surface are virtual surfaces, and the third surface S3 corresponds to the pupil HT (see FIG. 4).

The arrangement of each surface Si is specified by the surface vertex coordinates (x, y, z) and the rotation angle (ADE). The surface vertex coordinates of each surface Si are the local orthogonal coordinate system (X, y, z) in the global orthogonal coordinate system (x, y, z) with the surface vertex as the origin of the local orthogonal coordinate system (X, Y, Z). It is represented by the coordinates (x, y, z) of the origin of Y, Z) (unit: mm). In addition, the inclination of each surface Si is represented by an ADE around the X axis around the surface vertex or a rotation angle (α rotation). Further, the inclination of each surface Si is also expressed by a BDE around the Y axis about the surface vertex or a rotation angle (β rotation). The unit of the rotation angle is °, the clockwise direction when viewed from the positive direction of the X axis is the positive direction of the rotational angle of α rotation, and the clockwise direction when viewed from the positive direction of the Y axis is β rotation. The positive direction of the rotation angle. The global orthogonal coordinate system (x, y, z) is an absolute coordinate system that coincides with the local orthogonal coordinate system (X, Y, Z) of the pupil HT or the pupil plane (third surface S3). . That is, the arrangement data of each plane Si is expressed in a global coordinate system with the pupil plane center as the origin. In the pupil plane (third surface S3), the direction from the display screen 20 toward the pupil HT is the + Z direction or the + z direction, and the upward direction with respect to the pupil HT is the + Y direction or the + y direction. ) The left direction when viewed from the direction from 20 toward the pupil HT is the + X direction or the + x direction.

In each embodiment, the fifth surface S5 and the sixth surface S6 corresponding to the virtual image forming optical system 17 are free-form surfaces, and the free-form surface shape has the vertex of the optical surface as the origin and the Z axis in the optical axis direction. The sag amount Z of the surface parallel to the Z axis is expressed by the following “Equation 1”.
[Equation 1]

However,
Z: sag amount of plane parallel to Z axis c: vertex curvature (c = 1 / R)
k: conic constant or conic constant _C ^j: X m ^Y coefficient ⁿ R: Y radius of curvature

Hereinafter, specific examples of the head-up display device of the present invention will be described.

[Example 1]
The basic specifications of the head-up display device of Example 1 are shown in Table 1 below.
[Table 1]

The data of the optical surfaces and the like of Example 1 are shown in Table 2 below.
[Table 2]

Table 3 below shows surface data of the mirror portion of Example 1. “*” In the table represents a product, and “^” represents a power.
[Table 3]

The virtual image display device as a specific embodiment has been described above, but the virtual image display device according to the present invention is not limited to the above. For example, in the above-described embodiment, the display screen 20 can be disposed on the top of the windshield 8 or at the sun visor position by vertically inverting the arrangement of the virtual image display device 100. In this case, the display screen 20 is disposed obliquely downward and forward of the drawing unit 10. In the above embodiment, the display screen 20 is a flat surface, but it may be a curved surface, a curved surface further inclined, or a free curved surface having no symmetry.

In the above-described embodiment, the outline of the display screen 20 is not limited to a rectangle, but may be various shapes.

The main body optical system 13 shown in FIG. 3 and the like is merely an example, and the optical configuration of the main body optical system 13 can be changed as appropriate. For example, one or more mirrors having no optical power may be disposed in the optical path of the virtual image forming optical system 17. In this case, it may be advantageous for downsizing the drawing unit 10 and the like by folding.

In the above embodiment, the display position of the display image (virtual image) IM can be set discretely, or can be set continuously or intermittently.

In the above embodiment, the LCD is used as the drawing device. However, other types of display elements such as organic EL may be used. In this case, the light distribution angle of the organic EL is wide, the viewing angle can be widened, and the virtual image display device 100 can be reduced in weight.

In the above embodiment, the virtual image forming optical system 17 is provided with two mirrors. However, one or three or more mirrors may be provided. Further, the mirror may be omitted. Further, although the optical surface of the mirror is a free-form curved surface having symmetry, it is not limited to this and may be a free-form surface having no symmetry.

Further, in the above-described embodiment, the display screen 20 may be attached inside the rectangular reflection area provided in front of the windshield 8 or the windshield driver seat that forms the front window without providing the combiner. The display screen 20 can also be embedded in the windshield 8.

The virtual image display device 100 described above is not limited to a projection device mounted on an automobile or other moving body, but can be incorporated in a digital signage or the like, but can also be applied to other uses.

Claims

A virtual image display device comprising a drawing device, an enlarged projection optical system for enlarging an image of the drawing device, and a display screen,
An arrangement changing device for changing a projection distance by moving the drawing device in the optical axis direction;
A display controller that displays the plurality of virtual images with different projection distances by interlocking the drawing device and the arrangement changing device;
A virtual image display device.
2. The virtual image display device according to claim 1, wherein the display control unit displays the virtual image according to a position in a screen of the target object corresponding to the display screen when receiving the position information of the target object. .
3. The virtual image according to claim 1, wherein the display control unit adjusts the projection distance according to a spatial position of the object when receiving the position information of the object. Display device.
The virtual image display device according to any one of claims 1 to 3, wherein the display control unit causes the drawing device to display an image in synchronization with the movement of the drawing device by the arrangement changing device.
The virtual image display device according to any one of claims 1 to 4, wherein the drawing device operates at a frame rate of 60 fps or more.
The virtual image display device according to any one of claims 1 to 5, wherein a movement amount of the drawing device in an optical axis direction is 20 mm or less.
The virtual image display device according to any one of claims 1 to 6, wherein the arrangement changing device moves the drawing device at a speed of 15 Hz or more.
The virtual image display device according to any one of claims 1 to 7, wherein the drawing device is a liquid crystal display.
The virtual image display device according to any one of claims 1 to 7, wherein the drawing device is an organic EL.
A virtual image display device according to any one of claims 1 to 9,
An environment monitoring unit for detecting a spatial position of the object;
A display system for a moving body comprising: