JP2019191368A - Virtual image display device and head-up display device - Google Patents

Abstract

To provide a virtual image display device capable of displaying a virtual image at a plurality of projection distances substantially at the same time.SOLUTION: A virtual image display device 20 comprises a display element 21, a virtual image formation optical system 22 including a plurality of lenses, for enlarging an image formed in the display element 21 and converting the same into a virtual image to project the virtual image, a movement mechanism 30 changing projection distance to a virtual image f by changing a position in an optical axis direction of at least one lens 621 of the virtual image formation optical system 22, and a display control unit 50 controlling timing of displaying an image in the display element 21 according to a position of the lens 621 changed by the movement mechanism 30.SELECTED DRAWING: Figure 4

Description

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

  Conventional head-up displays (hereinafter, also simply referred to as “HUD”) generally generate a virtual image at a certain distance from the driver, and the display content by HUD includes vehicle speed, car navigation, and so on. It was limited to information. In the first place, the purpose of mounting the HUD on the 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 the vehicle speed, but also, for example, the front cars, pedestrians, obstacles, etc. are detected by cameras and sensors, and the driver is informed of the danger in advance through HUD. A system that prevents it is more preferable. In order to realize such a system, for example, it is conceivable to display a danger signal as a virtual image superimposed on a see-through image that is a target for detecting danger such as a car, a person, and an obstacle.

When displaying such a virtual image, the distance to the object to be perceived as dangerous is not constant. For example, when a danger signal is displayed and superimposed on a virtual image that is 2 meters ahead of a danger 50 meters ahead, there is a problem that the human eye feels uncomfortable because a difference in focal position occurs. As a method for solving such a problem, it is conceivable to superimpose a virtual image on the real object including the depth direction.
As described above, there is a method disclosed in the following Patent Document 1 as a method for giving a virtual image a depth. In this patent document 1, a scanning image forming means such as a MEMS (Micro Electro Mechanical Systems) mirror, a diffusion screen, a projection means, and a movable means for changing the position of the diffusion screen are provided, and a virtual image is obtained by changing the position of the diffusion screen. The position of is changed. The main purpose of Patent Document 1 is to reduce the driver's line-of-sight movement by moving the virtual image position closer or further away in view of the fact that the distance that a person gazes with changes in the speed of the vehicle.

JP 2009-150947 A

  However, when the virtual image position is uniformly moved away or brought close to the speed at the time of driving as in Patent Document 1, when the driver moves the face sideways and shifts the eye position, There is a problem that the position and the position of the virtual image such as the danger signal are shifted, and the driver misidentifies the danger signal.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a virtual image display device capable of displaying virtual images substantially simultaneously at a plurality of projection distances.

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

(1) a display element;
A virtual image forming optical system including a plurality of lenses, enlarging an image formed on the display element, converting the image into a virtual image, and projecting the virtual image;
A moving mechanism that changes a projection distance to the virtual image by changing a position in the optical axis direction of at least one of the lenses of the virtual image forming optical system;
A display control unit for controlling the timing of displaying an image on the display element according to the position of the lens changed by the moving mechanism;
A virtual image display device.

(2) The virtual image forming optical system includes a lens group including a plurality of lenses that are arranged at different fixed positions on the optical axis,
The virtual image display according to (1), wherein the moving mechanism changes a position of the lens in the optical axis direction by arranging any of a plurality of lenses constituting the lens group on the optical axis. apparatus.

(3) a display element;
A virtual image forming optical system including a plurality of lenses, enlarging an image formed on the display element, converting the image into a virtual image, and projecting the virtual image;
A moving mechanism that changes the projection distance to the virtual image by changing the lens on at least one optical axis of the virtual image forming optical system to a lens having a different focal length;
A display control unit that controls the timing of displaying an image on the display element according to the timing of changing the lens by the moving mechanism;
The virtual image forming optical system includes a lens group including a plurality of lenses having different focal lengths,
The moving mechanism is a virtual image display device in which one of a plurality of lenses constituting the lens group is arranged on an optical axis.

(4) The moving mechanism is a disk that rotates around a rotation axis parallel to the optical axis, and includes a disk in which the lenses of the lens group are arranged concentrically.
The virtual image display device according to (3), wherein the lenses of the lens group are sequentially arranged on the optical axis by rotating the disk.

(5) The virtual image display device according to any one of (1) to (4) above,
An object detection unit that detects an object existing in the detection region and determines a distance to the object;
A main control unit that causes the virtual image display device to form a virtual image at the projection distance corresponding to the distance to the object determined by the object detection unit;
A head-up display device comprising:

  According to the virtual image display device of the present invention, the virtual image forming optical system includes a plurality of lenses, enlarges an image formed on the display element, converts the image into a virtual image, and projects the virtual image. At least one lens of the virtual image forming optical system By changing the position in the optical axis direction, the moving mechanism that changes the projection distance to the virtual image, and the display control that controls the timing for displaying the image on the display element according to the position of the lens changed by the moving mechanism A section. Alternatively, a virtual image forming optical system that includes a plurality of lenses, enlarges an image formed on the display element, converts the image into a virtual image, and projects the image, and a lens on at least one optical axis of the virtual image forming optical system, has a focal length. A moving mechanism that changes the projection distance to the virtual image by changing to a different lens, and a display control unit that controls the timing of displaying the image on the display element according to the position of the lens changed by the moving mechanism, Prepare. Thereby, virtual images can be displayed substantially simultaneously at a plurality of projection distances.

It is sectional drawing which shows the state which mounted the head up display apparatus which concerns on this embodiment in the vehicle. It is the schematic diagram which looked at the vehicle carrying a 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 side view which shows the optical element group and movement mechanism in 1st Embodiment. It is a figure which shows the optical element group and movement mechanism in a modification. It is a side view which shows the optical element group and movement mechanism in 2nd Embodiment. It is a figure which shows the optical element group and movement mechanism in 3rd Embodiment. It is a block diagram which shows the hardware constitutions of a head up display apparatus. It is a perspective view which shows the specific display state.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios. In the drawings, the vertical direction is the Y direction, and in a state where the virtual image display device is mounted on the vehicle, the direction parallel to the traveling direction of the vehicle is the Z direction, and the direction perpendicular to these Y and Z directions is the X direction. The Z direction corresponds to the optical axis direction, and the X and Y directions correspond to the horizontal and vertical directions of the display element, respectively.

(First embodiment)
FIGS. 1 and 2 are schematic diagrams for explaining a use state in which the virtual image display device 20 according to the first embodiment and the head-up display device 10 including the virtual image display device 20 are mounted in a vehicle body 811 of a vehicle 800. The user (driver) 900 is sitting on the driver's seat 816 while holding the handle 813. As shown in FIGS. 1 and 2, the virtual image display device 20 of the head-up display device 10 directs image information displayed on a display element 21 (drawing device) described later to a user 900 via a display screen 223. Are displayed as virtual images f (f1, f2, and fn described later).

  The components other than the display screen 223 of the virtual image display device 20 are installed in the dashboard 814 of the vehicle body 811 so as to be embedded behind a 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 223 along the optical axis AX. The display screen 223 is a concave mirror or a plane mirror having translucency. The display screen 223 may function as a combiner or a windshield, or may have both functions. Moreover, you may provide the member provided with these functions separately. The display screen 223 is erected on the dashboard 814 with the lower end supported, and reflects the display light D1 from the virtual image display device 20 toward the rear side (Z direction) of the vehicle body 811. In other words, in the illustrated case, the display screen 223 is an independent type that is installed separately from the front window 812. The display light D1 reflected by the display screen 223 is guided to the eye 910 (eye box) (not shown) corresponding to the pupil 910 of the user 900 sitting in the driver's seat 816 and its peripheral position. The Eyebox is set so as to correspond to the position (height) of the pupil 910 of the user 900 sitting in the driver's seat 816 in a state where the head-up display device 10 is mounted on the vehicle 800. The user 900 can observe the display light D <b> 1 reflected by the display screen 223, that is, the virtual image f as a display image separated by a predetermined distance (also referred to as a virtual image distance or a projection distance) as if it is in front of the vehicle body 811. On the other hand, the user 900 can observe external light transmitted through the display screen 223, that is, a real image of a front scene, a car, and the like. As a result, the user 900 observes a virtual image f including driving-related information and the like formed by reflection of the display light D1 on the display screen 223 so as to be superimposed on the background image that has passed through the display screen 223, that is, the see-through image. it can.

  FIG. 3 is a schematic diagram illustrating a configuration of the virtual image display device 20 according to the first embodiment. As shown in FIG. 3, the virtual image display device 20 includes a display element 21, a virtual image forming optical system 22, a moving mechanism 30, and a display control unit 50. The virtual image forming optical system 22 includes an optical element group 221, a mirror 222, a display screen 223, and a housing 29. Each component of the virtual image display device 20 other than the display screen 223 is accommodated in the housing 29.

  The display element 21 has a two-dimensional display surface 21a. Each optical element of the virtual image forming optical system 22 cooperates with the display screen 223 to convert the image i1 formed on the display surface 21a into a virtual image f, enlarges it, and projects it in front of the user 900. The optical element group 221 includes one or more lenses. Further, FIG. 3 shows an example in which the reflecting surface includes one mirror 222 having a flat surface, but the present invention is not limited to this, and two or more reflecting surfaces may be formed by a flat or curved mirror.

  The display element 21 may be a reflective element such as DMD (Digital Micromirror Device) or LCOS (Liquid Crystal On Silicon), or may be a transmissive element such as liquid crystal. In particular, when a DMD is used as the display element 21, it is easy to switch images at high speed while maintaining brightness, which is advantageous for display in which the projection distance is changed. The display element 21 operates at a frame rate of 30 fps or higher, preferably 90 fps. This makes it easy to make it appear as if a plurality of virtual images f are simultaneously displayed at different virtual image distances.

  The display control unit 50 includes a CPU (Central Processing Unit) and a memory constituted by a semiconductor or a magnetic disk, and executes a program stored in the memory, thereby executing a moving mechanism 30 and a display element described below. 21 is controlled. By controlling these, the display control unit 50 controls the formation timing of the image i1 displayed on the display element 21, and the three-dimensional virtual images f1 to fn in which the virtual image distance (projection distance) changes behind the display screen 223. Is displayed. Specifically, as described later, the moving mechanism 30 moves the positions of one or more lenses included in the optical element group 221 on the optical axis AX. By controlling the timing at which an image is displayed on the display element 21 in synchronization with the change in position, the virtual image distance to the virtual image f is changed. By performing this in a short time, the user 900 can simultaneously visually recognize a plurality of virtual images f (f1 to fn) having different projection distances.

  FIG. 4 is a side view showing the optical element group 221 and the moving mechanism 30 in the first embodiment. The optical element group 221 includes a first lens group 61, a lens 621, and a second lens group 63.

  In the first embodiment and the other embodiments described below, the intermediate screen is omitted, but immediately downstream of the first lens group 61, that is, between the first lens group 61 and the lens 621. An intermediate screen may be arranged on the screen. The intermediate screen is a diffusing plate that includes a frosted glass, a lens diffusing plate, a microlens array, and the like, has a diffusing function, and controls the light distribution angle to a desired angle. In the form in which the intermediate screen is arranged, an intermediate image is formed on the intermediate screen at the image forming position of the lens group 61. Then, the intermediate image formed on the intermediate screen is converted into a virtual image f by the rear lens 621 and the second lens group 63 and is projected in front of the user 900.

  In the first embodiment shown in FIG. 4, an image i1 formed on the display surface 21a of the display element 21 includes a first lens group 61, a lens 621, and a second lens group that constitute the optical element group 221. By 63, the image is enlarged, converted into a virtual image, and projected in front of the user 900. In the first embodiment, the moving mechanism 30 moves the lens 621 on the optical axis AX, that is, changes the position in the optical axis AX direction.

  The moving mechanism 30 in the first embodiment includes an actuator 31 and a position detection sensor 32. The actuator 31 includes a drive source such as a stepping motor and a mechanism such as a belt drive unit that converts the rotational motion of the drive source into linear motion. When the actuator 31 is operated by a control signal from the display control unit 50, the lens 621 slides on the optical axis AX (in the direction of the arrow in the drawing).

  The position detection sensor 32 functions as a detection unit, and detects the position of the lens 621 or a holding member (not shown) that holds the lens 621 in the optical axis AX direction. As the position detection sensor, a linear encoder, a Hall element, a photo sensor, or the like can be used. The position of the lens 621 on the optical axis AX is detected by the position detection sensor 32, and a position data signal (detection signal) is sent to the display control unit 50.

  The display control unit 50 controls the actuator 31 to reciprocate the lens 621 on the optical axis AX at a predetermined cycle. The predetermined period is, for example, several tens of Hz. At this time, image data is output to the display unit 21 in synchronization with the detection signal from the position detection sensor 32, and an image i1 and a virtual image f are formed. In FIG. 4, reference numerals f <b> 1, f <b> 2, and fn are attached to correspond to the positions of the moved lenses 621 (partially indicated by broken lines). This indicates that the virtual images f1, f2, and fn shown in FIG. 3 are formed at a projection distance corresponding to the position (the same applies hereinafter). Also in FIG. 4, the projection distance becomes the longest when the lens 621 is moved to the rightmost side corresponding to the symbol fn, and the projection distance becomes the shortest on the leftmost side corresponding to the symbol f1. This is a case where the lens 621 is moved. Note that n of fn represents an integer of 3 or more, and the position of the lens 621 is not limited to three stages, and can be moved to a multistage position.

  As described above, in the virtual image display device 20 according to the first embodiment, the lens 621 of the virtual image forming optical system 22 is slid on the optical axis AX by the actuator 31 of the moving mechanism 30, thereby the optical axis direction of the lens 621. The display control unit 50 outputs image data to the display element 21 according to the position of the lens 621 that is moved by the moving mechanism 30 and detected by the position detection sensor 32, and the timing for displaying the image is changed. Control. Thereby, the virtual images f at a plurality of projection distances can be displayed substantially simultaneously.

(Modification)
In the first embodiment, the position detection sensor 32 is provided. However, the position detection sensor 32 may be omitted if the drive source is a drive source whose rotational position is known by the drive source itself, such as a stepping motor. . In this case, the control circuit of the stepping motor also functions as a detection unit, and the display control unit 50 can acquire position data directly from the control circuit. FIG. 5 is a diagram showing an optical element group and a moving mechanism in such a modification. In the modification shown in FIG. 5, the control circuit of the stepping motor that constitutes the actuator 33 also functions as a detection unit, and the control unit 50 displays an image on the display element 21 based on the encoder signal from the actuator 33. To control.

(Second Embodiment)
FIG. 6 is a side view showing the optical element group 221 and the moving mechanism 30 in the second embodiment. Except for the configuration shown in the figure, the second embodiment is the same as the first embodiment, and a description thereof will be omitted. The optical element group 221 shown in FIG. 6 includes a first lens group 61, a second lens group 63, and a third lens group 64. The third lens group 64 includes three lenses 641 to 643. Each of the three lenses 641 to 643 is configured to be arranged at a predetermined fixed position on the optical axis AX. In addition, although the example comprised by the three lenses 641-643 is shown in FIG. 6, two or four or more may be sufficient. Only one of these lenses 641 to 643 is moved on the optical axis AX (the center of the lens coincides with the optical axis AX) by the actuator 34 (in the direction of the arrow in the figure), and the other lenses are retracted. Held in. In the example of FIG. 6, it is shown that only the leftmost lens 641 is moved on the optical axis AX. Similarly to the actuator 32 used in the first embodiment, the actuator 34 includes a drive source such as a stepping motor and a mechanism such as a belt drive unit that converts the rotational motion of the drive source into linear motion. Each of the lenses 641 to 643 is a lens having the same configuration, and by arranging one of a plurality of lenses on the optical axis AX, as in the first embodiment shown in FIG. The position in the optical axis direction is changed. Thereby, a virtual image f (f1, f2, fn) is formed at a projection distance corresponding to the position of the lens arranged on the optical axis AX. In the second embodiment, the lens is substantially the same as that in which the lens is discretely moved in the optical axis AX direction. In this respect, the first lens in which the lens is continuously moved in the optical axis AX direction is used. Different from the embodiment.

  Also in the virtual image display device 20 according to the second embodiment as described above, any of a plurality of lenses constituting the lens group 64 of the virtual image forming optical system 22 is arranged on the optical axis AX by the actuator 34 of the moving mechanism 30. Thus, the position of the lens in the optical axis direction is substantially changed, and an image is displayed on the display element 21 by the display control unit 50 in synchronization with the position of the changed lens, that is, on the optical axis AX. Control timing. Thereby, the virtual images f of a plurality of projection distances can be displayed substantially simultaneously as in the first embodiment.

(Third embodiment)
FIG. 7 is a diagram illustrating the optical element group 221 and the moving mechanism 30 in the third embodiment. Fig.7 (a) is the front view seen from the Z direction (optical axis AX direction), and FIG.7 (b) is a side view. Except for the configuration shown in the figure, the second embodiment is the same as the first embodiment, and a description thereof will be omitted. The optical element group 221 shown in FIG. 7 includes a first lens group 61, a second lens group 63, and a fourth lens group 65. The fourth lens group 65 includes lenses 651 to 656, each having a different focal length. For example, the focal length increases in the order of the lenses 651 to 656. The lenses 651 to 656 are held concentrically on the disc 352 with respect to the rotation axis s1. That is, the distance from the rotation axis s1 to the center position of each lens 651 is equal. The rotation axis s1 is an axis parallel to the optical axis AX, and the disk 352 rotates on the XY plane, that is, the coordinates in the Z direction (optical axis AX direction) of the centers of the lenses 651 to 656 are the same. .

  The moving mechanism 30 includes an actuator 35 and a position detection sensor 36. The actuator 35 includes a drive motor 351 and a disk 352. The drive motor 351 is rotated by a control signal from the display control unit 50, so that the lenses 651 to 656 of the lens group 65 are sequentially arranged on the optical axis AX. Thereby, the projection distance of the virtual image f can be changed according to the focal length of the lens to be arranged. The rotational position of the disk 352 is detected by a position detection sensor 36 including a hall element, a photo sensor, and the like. The disk 352 is preferably controlled to rotate at a constant angular velocity, but may be rotated intermittently. For example, by forming the image i1 on the display surface 21a of the display element 21 at the timing when the lenses 651 and 652 are respectively arranged on the optical axis AX, the virtual images f1 and f2 are respectively formed at the projection distance according to the focal length of the lens. It is formed. In the example shown in FIG. 7, an example using six lenses is shown, but the present invention is not limited to this, and the number of lenses may be smaller or larger. Further, the focal length may not be different for all of the plurality of lenses, and the focal length may be the same for some lenses.

  As described above, in the virtual image display device 20 according to the third embodiment, the plurality of lenses 651 to 656 are rotated by rotating the disk 352 in which the lenses 651 to 656 having different focal lengths of the lens group 65 are arranged concentrically. Are sequentially arranged on the optical axis AX, and the lens on the optical axis is changed. The display control unit 50 controls the timing for displaying an image on the display element 21 in accordance with the timing for changing the lens. Thereby, the virtual images f of a plurality of projection distances can be displayed substantially simultaneously as in the first and second embodiments.

(Head-up display device 10)
FIG. 8 is a block diagram illustrating a 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, 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 three-dimensional virtual image corresponding to an object such as an oncoming vehicle or a passerby. A display example of the virtual image will be described later.

  The driver detection unit 71 is a part that detects the presence of the user 900 and the viewpoint position in the vehicle 800, and includes an internal camera 71a facing the driver's seat 816, an image processing unit 71b for the driver's seat, and a determination unit 71c. . The internal camera 71a is installed on the dashboard 814 in the vehicle body 811 so as to face the driver's seat 816 (see FIG. 2), and takes an image of the head of the user 900 sitting on the driver's seat 816 and its surroundings. To do. The driver seat image processing unit 71b performs various types of image processing such as brightness correction on the image captured by the internal camera 71a to facilitate processing by the determination unit 71c. The determination unit 71c detects the head and eyes (pupil 910) of the user 900 by extracting or cutting out an object from the driver seat image processed by the driver seat image processing unit 71b, and is attached to the driver seat image. The spatial position of the user's 900 eyes (resulting in the direction of the line of sight) is calculated along with the presence / absence of the user's 900 head in the vehicle body 811 from the depth information.

  The environment monitoring unit 72 functions as an object detection unit. The environment monitoring unit 72 identifies objects such as cars, bicycles, and pedestrians that are close to 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 positions inside and outside the vehicle body 811 and captures an external image such as the front or side of the user 900 or the vehicle 800. 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, thereby facilitating the processing in the determination unit 72c. The determination unit 72c detects the presence / 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 external image processing unit 72b, and depth information associated with the external image From the above, the spatial position of the object in front of the vehicle 800 is calculated.

  The internal camera 71a and the external camera 72a include, for example, a compound eye type three-dimensional camera. That is, the cameras 71a and 72a are obtained by arranging camera elements, each of which includes an imaging lens, a CMOS (Complementary Metal-Oxide Semiconductor), and other imaging elements, in a matrix. Drive circuits. The plurality of camera elements constituting each of the cameras 71a and 72a are focused on, for example, different positions in the depth direction, or can detect relative parallax, and are obtained from each camera element. By analyzing the state of the image (focus state, object position, etc.), the distance to each region or object in the image is determined.

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

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

  The display control unit 50 operates the virtual image display device 20 under the control of the main control unit 60 to display a three-dimensional virtual image f whose projection distance (also referred to as “virtual image distance”) changes behind the display screen 223. Let The display control unit 50 generates a virtual image f to be displayed on the virtual image display device 20 from display information including the display shape and display distance received from the environment monitoring unit 72 via the main control unit 60. The virtual image f is, for example, a frame F (see FIG. 9) located in the periphery with respect to the depth position direction with respect to a car, a bicycle, a pedestrian, or other object OB (see FIG. 9 described later) existing behind the display screen 223. It becomes a sign like this.

  The display control unit 50 receives a detection output related to the presence of the user 900 and the eye position from the driver detection unit 71 via the main control unit 60. Thereby, the projection of the virtual image f by the virtual image display device 20 can be automatically started and stopped. It is also possible to project the virtual image f only in the direction of the line of sight of the user 900. Further, it is possible to perform projection with emphasis such as brightening or blinking only the virtual image f in the direction of the line of sight of the user 900.

  FIG. 9 is a perspective view illustrating a specific display state. The front of the user 900 who is a driver (observer) is a detection region DF corresponding to the observation field. Within the detection area DF, that is, on the road and its surroundings, there are objects OB1 and OB3 of a person such as a pedestrian and a moving object OB2 such as a car. In this case, the main control unit 60 of the head-up display device 10 projects a three-dimensional virtual image f (f1 to f3) by the virtual image display device 20, and a frame F1 as a related information image for each object OB1 to OB3. , F2 and F3 are added. At this time, since the distances from the user 900 to the objects OB1 to OB3 are different, the projection distances to the virtual images f1, f2, and f3 for displaying the frames F (F1 to F3) are determined by the user 900 or the environment monitoring unit 72 determined. This corresponds to the distance from the vehicle 800 to each of the objects OB1 to OB3.

  In the virtual image display device 20 according to the first embodiment of FIG. 4, the display control unit 50 displays the display element 21 at a timing when the virtual image f1 at the short distance (first distance) moves the lens 621 to the leftmost side. Display the image i1. Similarly, in the virtual image f2 at the intermediate distance (second distance), the image i1 is displayed on the display element 21 at a timing when the lens 621 is moved to the right side by a predetermined amount. In the virtual image f3 at a long distance (third distance), the image i1 is displayed on the display element 21 at the timing of moving the lens 621 to the rightmost side (position fn in FIG. 4). In addition, if the projection distance of the virtual images f1 to f3 is a form in which the lens 621 is continuously slid on the optical axis AX as in the first embodiment, the projection distance of the virtual image f is also continuously changed. Can do. On the other hand, if it is a form arranged discretely on the optical axis AX as in the second embodiment of FIG. 6, the projection distance of the virtual image f is also changed discretely. In this case, the actual distance from the objects OB1 to OB3 may not exactly match. However, if the difference between the projected distances of the virtual images f1, f2, and f3 and the actual distances to the objects OB1, OB2, and OB3 is not large, parallax hardly occurs even if the viewpoint of the user 900 moves (in the X direction). The arrangement relationship between the objects OB1, OB2, and OB3 and the frames F1, F2, and F3 can be substantially maintained.

  According to the virtual image display device 20 and the head-up display device 10 including the virtual image display device 20 according to the embodiment described above, an image formed on the display element is enlarged and converted into a virtual image including a plurality of lenses. A virtual image forming optical system for projecting is provided. By changing the position of at least one lens of the virtual image forming optical system in the optical axis direction or by changing to a lens having a different focal length, the virtual image is continuously or discretely at a plurality of distances. Can be displayed. This makes it possible to superimpose a danger warning signal or other virtual image (for example, frame F) on the object OB that is seen through including the depth direction, that is, the real object or the see-through image. As a result, even if the position of the eyes changes from a distance to the vicinity, it is possible to suppress the deviation between the virtual image and the real object, and when the virtual image display device 20 is applied to a driving support system such as the head-up display device 10, System safety can be further increased.

(Other variations)
The configuration of the virtual image display device described above and the head-up display device including the virtual image display device has been described with reference to the main configuration in describing the features of the above-described embodiment, and is not limited to the above configuration. Various modifications can be made within the range. Further, the configuration of a general virtual image display device or a head-up display device is not excluded.

  For example, in each of the above-described embodiments, one lens is slid on the optical axis AX, or is disposed at a different position on the optical axis, or one of a plurality of lenses having different focal lengths. Alternatively on the optical axis AX, the projection distance to the virtual image was changed. However, a lens set composed of a plurality of lenses may be slid and arranged at different positions on the optical axis. Further, a lens set composed of a plurality of lenses having different focal lengths may be provided, and any of these lens sets may be alternatively arranged on the optical axis AX.

DESCRIPTION OF SYMBOLS 10 Head-up display apparatus 20 Virtual image display apparatus 21 Display element 21a Display surface 22 Virtual image formation optical system 221 Optical element group 61 1st lens group 621 Lens 63 2nd lens group 64 3rd lens group 641-643 Lens 65 1st 4 lens group 651-656 lens 222 mirror 223 display screen 29 housing 30 moving mechanism 31, 33, 34, 35 actuator 32, 36 position detection sensor 351 drive motor 352 disk 50 display control unit 60 main control unit 71 driver detection unit 72 Environment Monitoring Unit 800 Vehicle 811 Car Body 812 Front Window 813 Handle 814 Dashboard 815 Display 816 Driver's Seat 900 User 910 Eye AX Optical Axis D1 Display Light f Virtual Image

Claims (5)

A display element;
A virtual image forming optical system including a plurality of lenses, enlarging an image formed on the display element, converting the image into a virtual image, and projecting the virtual image;
A moving mechanism that changes a projection distance to the virtual image by changing a position in the optical axis direction of at least one of the lenses of the virtual image forming optical system;
A display control unit for controlling the timing of displaying an image on the display element according to the position of the lens changed by the moving mechanism;
A virtual image display device. The virtual image forming optical system includes a lens group including a plurality of lenses that are arranged at different fixed positions on the optical axis,
The virtual image display device according to claim 1, wherein the moving mechanism changes a position of the lens in the optical axis direction by arranging any of a plurality of lenses constituting the lens group on the optical axis. . A display element;
A virtual image forming optical system including a plurality of lenses, enlarging an image formed on the display element, converting the image into a virtual image, and projecting the virtual image;
A moving mechanism that changes the projection distance to the virtual image by changing the lens on at least one optical axis of the virtual image forming optical system to a lens having a different focal length;
A display control unit that controls the timing of displaying an image on the display element according to the timing of changing the lens by the moving mechanism;
The virtual image forming optical system includes a lens group including a plurality of lenses having different focal lengths,
The moving mechanism is a virtual image display device in which one of a plurality of lenses constituting the lens group is arranged on an optical axis. The moving mechanism is a disk that rotates around a rotation axis parallel to the optical axis, and has a disk in which the lenses of the lens group are arranged concentrically.
The virtual image display device according to claim 3, wherein the lenses of the lens group are sequentially arranged on the optical axis by rotating the disk. The virtual image display device according to any one of claims 1 to 4,
An object detection unit that detects an object existing in the detection region and determines a distance to the object;
A main control unit that causes the virtual image display device to form a virtual image at the projection distance corresponding to the distance to the object determined by the object detection unit;
A head-up display device comprising: