JP6279881B2 - Virtual image display device - Google Patents

Description

  The present invention relates to a virtual image display device in which an observer visually recognizes a stereoscopic image.

  2. Description of the Related Art A head-up display device that projects an image on a windshield of a vehicle and displays the projected image as a virtual image that is superimposed on a front landscape is known. This device is recognized as a useful video display device because it requires little movement of the viewpoint, particularly for a driver who needs to look closely ahead. In recent years, the need for this device is increasing from the viewpoint of safe driving support.

  In order to make the virtual image superimposed on the scenery in front of the driver more uncomfortable and realistic, a proposal has been made to display a stereoscopic virtual image. In order to show a three-dimensional image, a right-eye image and a left-eye image are incident on the left and right eyes, respectively. Three-dimensional images can be seen by combining the left and right images in the human brain.

  Patent Document 1 discloses a virtual image display device in which an image projected from an optical unit is reflected by a half mirror so that a stereoscopic image can be visually recognized as a virtual image by the half mirror from the viewpoint of an observer. In the virtual image display device of Patent Document 1, a projection optical system including a display element for displaying an image, a light source that illuminates the display element, and a projection lens that projects an image displayed on the display element is provided to the left and right eyes of the observer. Two sets are provided correspondingly. Further, a lens group is disposed at the image formation position of the image by the two sets of projection optical systems. This lens group consists of a condensing Fresnel lens in which the exit pupil of the projection lens and the observer's viewpoint are in a conjugate relationship, and light rays from one of the left and right eyes of the observer to the other viewpoint. It consists of a microlens array that diffuses to the extent that it is not reflected.

JP-A-2005-70255

  However, in the method of Patent Document 1, when a left eye image and a right eye image are projected to the left and right eyes in order to generate a stereoscopic virtual image, two sets of optical systems for the left eye and the right eye are used. Need. Therefore, two sets of expensive optical parts are required, and the apparatus price is expensive. Furthermore, various lens groups are required to form an image. An optical lens is an expensive part, for example, a very expensive part compared to an optical part such as a concave mirror or a convex mirror. For this reason as well, the price of the apparatus was expensive.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide two optical paths for images projected respectively for the left eye and the right eye in a virtual image display device in which a viewer visually recognizes a stereoscopic image. By realizing with one set of optical systems that do not use a lens, the cost of the apparatus is reduced.

  The virtual image display device of the present invention is a virtual image display device in which an observer visually recognizes a stereoscopic image, a display device that projects a left eye image and a right eye image, the left eye image, and the right eye image. And a concave mirror that reflects the left-eye image and the right-eye image reflected by the convex mirror, and the convex mirror and the concave mirror respectively reflect the left-eye image. A virtual image display device having an integral structure including a left-eye reflecting portion and a right-eye reflecting portion that reflects the right-eye image.

  According to the present invention, in a virtual image display device in which an observer visually recognizes a stereoscopic image, by realizing two optical paths of images projected for the left eye and the right eye, respectively, with a set of optical systems that do not use an optical lens. The price of the apparatus can be reduced.

It is a figure which shows the structure of the head-up display apparatus which is a virtual image display apparatus of the 1st Embodiment of this invention. It is a figure which shows the display machine used for the head-up display apparatus of the 1st Embodiment of this invention. It is a figure showing the structure which looked at the head up display device of a 1st embodiment of the present invention from the side. It is a figure which shows Eyebox of the head-up display apparatus of the 1st Embodiment of this invention. It is a figure which shows the optical path of the video information for right eyes of the head-up display apparatus of the 1st Embodiment of this invention. It is a figure which shows the optical path of the video information for left eyes and right eyes of the head-up display apparatus of the 1st Embodiment of this invention. It is a figure which shows the structure of the head-up display apparatus which is a virtual image display apparatus of the 2nd Embodiment of this invention. It is a figure which shows the mode of the movement of Eyebox of the head-up display apparatus of the 2nd Embodiment of this invention. It is a figure which shows the modification of the head-up display apparatus which is a virtual image display apparatus of the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the preferred embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following.
(First embodiment)
(Description of structure)
FIG. 1 shows the structure of a head-up display device that is a virtual image display device according to a first embodiment of the present invention. In FIG. 1, portions that do not affect the present embodiment, such as the housing portion of the apparatus, are omitted.

  As shown in FIG. 1, the head-up display device of the present embodiment includes a display device 1 serving as a light source. The display 1 projects video information including a light beam 2L for left-eye video information and a light beam 2R for video information for the right eye. An optical unit 3 is provided at a destination for projecting the video information. The optical unit 3 includes a concave mirror 31 and a convex mirror 32. The concave mirror 31 and the convex mirror 32 respectively include left-eye reflecting portions 33L and 34L and right-eye reflecting portions 33R and 34R that reflect the light beam 2L of the image information for the left eye and the light beam 2R of the image information for the right eye, respectively. Have.

  If the optical path of the video information needs to be folded or folded due to restrictions on the outer shape of the apparatus, a plurality of mirrors can be added to the optical unit 3.

At the tip of the optical unit 3, a windshield 4 formed of transparent or translucent glass or the like is provided. There is an observer 5 at the tip of the windshield 4, and the left eye 5L and the right eye 5R of the observer 5 have a light beam 2L of video information for the left eye and a light beam 2R of video information for the right eye reflected by the windshield 4. Each incident. Although the shape of the windshield 4 can have a free-form surface, it is treated as a plane here for the sake of simplicity.
(Description of operation)
First, the projection of video information by the display device 1 will be described. The display device 1 shown in FIG. 2 can use a method such as laser light or DLP (Digital Light Processing) (registered trademark), and is not limited to a specific method in this embodiment. Further, the method of dividing the projection of the video information from the display device 1 into the light beam 2L of the video information for the left eye and the light beam 2R of the video information for the right eye uses a method using a half mirror or polarization. In this embodiment, the method is not limited to a specific method.

  When dividing the projection of the video information from the display device 1 into the light beam 2L of the video information for the left eye and the light beam 2R of the video information for the right eye, the display of the display device 1 is divided into left and right, The left-eye video information 1L can be projected from the left side of the display device 1, and the right-eye video information 1R can be projected from the right side. At this time, the display device 1 prevents the right-eye video information 1R from being mixed with the left-eye video information light 2L, or prevents the left-eye video information 1L from being mixed with the right-eye video information light 2R. In addition, or between the display 1 and the optical unit, directivity can be given to the left and right video information by a polarizing plate (not shown in FIGS. 1 and 2).

  In addition, when incorporating the display device 1 in the apparatus, if the vertical direction of the display device 1 is changed, it can be dealt with by switching the left and right of the projected image.

  Next, an operation after the video information projected from the display device 1 enters the optical unit 3 will be described. FIG. 3 is a diagram showing a structure of the head-up display device of this embodiment as viewed from the side. As shown in FIG. 3, the video information projected from the display device 1 is reflected by the convex mirror 32 and travels toward the concave mirror 31. At this time, the light ray of the video information is enlarged according to the curvature of the convex mirror before entering the concave mirror 31. Further, the light ray of the video information is reflected by the concave mirror 31 and then reduced according to the curvature of the concave mirror.

  Note that FIG. 3 shows how the light rays of the video information are enlarged and reduced in the vertical direction. However, the convex mirror 32 and the concave mirror 31 have a spherical or aspherical curved surface and are in the horizontal direction, that is, FIG. The same enlargement and reduction are also performed in the depth direction.

  At this time, as shown in FIG. 1, the left-eye image information beam 2L is reflected by the left-eye reflecting portions 33L and 34L of the concave mirror 31 and the convex mirror 32, and the right-eye image information beam 2R is reflected by the concave mirror 31. Are reflected by the right-eye reflecting portions 33R and 34R of the convex mirror 32.

  The light beam that has passed through the optical unit 3 is transmitted through the semi-transparent windshield 4, part of it is lost, and part of it is reflected, and the reflected light reaches the eye 51. Thereby, the observer 5 can see a virtual image. At this time, the angle at which the image is reduced by the concave mirror is the viewing angle of the virtual image that the observer 5 sees as it is.

  In addition, since the position of the eye 51 of the observer 5 varies depending on the individual, as shown in FIG. 4, an eyebox 52 that is a range in which a virtual image can be visually recognized within a desired range is provided. Optical design can be performed. In the Eyebox 52, the target image can be visually recognized wherever the eye 51 is located.

  The Eyebox 52 can control the range by the radius of curvature of the convex mirror 32 and the concave mirror 31 and the distance between components. FIG. 3 shows the path of the light beam that enters the pupil of the eye 51, but in reality, the light beam is projected from the display device 1 with a certain solid angle. The light beams having various angles are collected in the range of the Eyebox 52 by the optical design of the optical unit 3. Therefore, within the range of Eyebox 52, a virtual image can be visually recognized even if the position of the eye 51 moves up, down, left, and right.

  The range of Eyebox 52 can be set as follows. That is, the distance between the pupils of the left and right eyes of a person is about 60 to 65 mm on average. For this reason, the right and left eyes can be set within a range of 30 mm or less on the inner side and in an arbitrary range on the outer side with the average pupil position as the center for both the left and right eyes. In addition, the vertical direction is set in a range in which distortion that cannot be corrected does not occur in the video and in a realistic range corresponding to the width in the horizontal direction, for example, 30 mm on the upper side and 30 mm on the lower side. Can do.

  In the description of the operation using FIGS. 3 and 4 so far, the light of the video information has been described without being divided into the left and right eyes. In order to visually recognize a three-dimensional video, it is necessary to make the video information for the right eye and the video information for the left eye enter each of the left and right eyes. For that purpose, the optical paths of the light beams for the left eye and the right eye are required. Below, the example which implement | achieves the two optical paths for left eyes and right eyes which are the characteristics of this embodiment only by one set of optical units is demonstrated.

  In order to realize the two optical paths with one set of optical units, the arrangement of the concave mirror 31 and the convex mirror 32 which are elements of the optical unit 3 is characteristic. FIG. 5 is a view of the optical path of the video information for the right eye of the head-up display device as viewed from above. In FIG. 5, a portion corresponding to the right-eye reflecting portion 33R of the concave mirror 31 in the optical unit 3 of FIG. 1 is a concave mirror 31R, and a portion corresponding to the right-eye reflecting portion 34R of the convex mirror 32 is a convex mirror 32R. In FIG. 5, the windshield is omitted.

  In the configuration of FIG. 5, when the center point 31C of the radius of curvature of the concave mirror 31R and the center point 32C of the radius of curvature of the convex mirror 32R are positioned in front of the optical unit 3, the observer 5 It is located in the plane of a plane (hereinafter referred to as the center plane 7) that includes the center of a straight line connecting the pupils of the left and right eyes and is perpendicular to the straight line.

  Since the center point 31C and the center point 32C are located in the center plane 7, the image information 1R for the right eye is visually recognized only by the right eye 5R. That is, the image information 1R for the right eye projected from the display device 1 by the concave mirror 31R and the convex mirror 32R reaches the right eye 5R as a ray having a certain directivity toward the Eyebox 52R. At this time, since the light beam has directivity, the left-eye image information 1R cannot be visually recognized by the left eye (not shown in FIG. 5) located at a position deviated from the Eyebox 52R.

  This constant directivity is such that the right-eye video information 1R does not protrude rightward across the center plane 7 when the right-eye video information 1R reaches the Eyebox 52R along the optical path 21R for the right eye. If it is sex. This directivity can be given to the left and right video information by the polarizing plate in the display device 1 or between the display device 1 and the optical unit, as described above.

  That is, since the center point 31C and the center point 32C are located within the plane of the center surface 7, the optical path 21R for the right eye is opposite to the position of the Eyebox 52R across the center surface 7 at the position of the Eyebox 52R. It can be prevented from reaching.

  On the other hand, in FIG. 5, when the center point 31C or the center point 32C is shifted to the right side with respect to the center surface 7, the optical path 21R for the right eye is opposite to the position of the Eyebox 52R across the center surface 7 May occur. In this case, the left eye not shown in FIG. 5 visually recognizes the video information 1R for the right eye. However, also in this case, it is possible to prevent the left eye from visually recognizing the video information 1R for the right eye by narrowing the Eyebox 52R. However, the degree of freedom in designing the Eyebox 52R is narrowed.

  When the concave mirror 31R and the convex mirror 32R are actually arranged, the optical design of the radius of curvature of each mirror and the optical path length from the display 1 to the right eye 5R of the observer 5 is individually determined according to the size of the apparatus and the installation method. Can be implemented in response to the demands of At this time, the size of the Eyebox 52R can be kept within a range not exceeding the center surface 7. Thereby, the video information for the right eye can be incident only on the right eye.

  The arrangement of the optical unit with respect to the right eye 5R has been clarified using FIG. Next, as shown in FIG. 6, the optical unit for the left eye 5 </ b> L is arranged at a position that is plane-symmetric with respect to FIG. Accordingly, the concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32L each have a common center point, that is, the center point 31C of the concave mirror and the center point 32C of the convex mirror.

  Accordingly, the concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32L have the same radius of curvature, and can be part of the concave mirror 31 and the convex mirror 32. That is, the concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32L can be formed as the concave mirror 31 and the convex mirror 32, which are one component, respectively.

  According to the configuration of FIG. 6, the image information 1R for the right eye is visually recognized only by the right eye 5R through the optical path 21R for the right eye, and the image information 1L for the left eye is visually recognized only by the left eye 5L by the optical path 21L for the left eye.

  When the concave mirror 31 and the convex mirror 32 are made of glass, according to the configuration of FIG. 6, the concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32 are each smoothly connected with the same radius of curvature. Therefore, manufacture becomes easy. Further, when the concave mirror 31 and the convex mirror 32 are made of resin, the concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32 are easy to manufacture even if the shape is more complicated than that of glass. Since each has a smoothly connected shape, manufacturing is facilitated.

  In the above description, the concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32 are described as spherical shapes having the same radius of curvature, but the spherical shape is not limited. The concave mirror 31R and the concave mirror 31L, and the convex mirror 32R and the convex mirror 32, even in the case of an aspherical shape, are symmetric with respect to each other via the center surface 7, so that the concave mirror 31R and the concave mirror 31L and the convex mirror 32R and the convex mirror 32 are provided. Can be connected smoothly. This facilitates the manufacture of the integrated concave mirror 31 and convex mirror 32 using glass or resin as a material.

As described above, according to the present embodiment, in the virtual image display device in which the observer visually recognizes a stereoscopic image, the two optical paths of the images projected respectively for the left eye and the right eye are formed by a set of optical systems that do not use an optical lens. It can be realized, and the price of the apparatus can be reduced.
(Second Embodiment)
As a second embodiment of the present invention, a virtual image display device will be described in which a mirror having a tilt drive mechanism is added to make the Eyebox position vertically and horizontally movable. The virtual image display device of the present embodiment is a head-up display device in which the position of the Eyebox can be adjusted.

  The positions of human eyes vary from person to person, and if the position and size of the Eyebox assuming the positions of the eyes of all persons are to be realized, the apparatus size becomes large. Therefore, enabling the position of the Eyebox to be moved allows a large number of observers to adjust the stereoscopic virtual image to a position suitable for the eyes of each individual while suppressing the apparatus size. As a method of adjusting the position of the Eyebox, a method in which the observer himself / herself manually operates a button or a knob or the like, a method in which the position of the observer's eyes is automatically detected using a sensor, and an automatic adjustment is performed. Etc. are possible.

  FIG. 7 shows the structure of a head-up display device according to the second embodiment of the present invention. As shown in FIG. 7, the configuration of the optical unit using the concave mirror 31 and the convex mirror 32 is the same as that of the first embodiment. In FIG. 7, mirrors 8R and 8L that reflect the light beam projected from the display device 1 toward the convex mirror 32, and drive units 9A and 9B for tilting the mirrors 8R and 8L, and a rotating shaft 10R, 10L is provided. Furthermore, a drive unit 9V for tilting the concave mirror 31 and a rotating shaft 10V are provided.

  First, an operation for moving the position of the Eyebox in the left-right direction will be described. In order to simplify the description, the optical path of the right eye 5R will be described as an example. The mirror 8R is tilted about the rotation axis 10R by the drive unit 9R. As a result, the entire optical path after the mirror 8R is tilted, and the position of the light beam finally projected to the position of the observer 5 moves in the left-right direction. As shown in FIG. 8, the Eyebox 52R of the right eye 5R can be moved in the left-right movement direction 53R according to the tilt amount at the mirror 8R. Similarly, by tilting the mirror 8L, the Eyebox 52L of the left eye 5L can be moved in the left-right direction. The Eyebox 52R and the Eyebox 52L can be moved independently.

  Next, an operation for moving the Eyebox position in the vertical direction will be described. The basic operation is the same as that in the left-right direction, and the concave mirror 31 is tilted about the rotation axis 10V by the drive unit 9V. As a result, the entire optical path after the concave mirror 31 is tilted, and the position of the light beam finally projected to the position of the observer 5 moves in the vertical direction. As shown in FIG. 8, the Eyeboxes 52R and 52L can be moved in the vertical movement direction 53V according to the tilt amount of the concave mirror 31.

  In the left-right direction, the mirror tilting direction may be the same or opposite for the left and right eyes, so it was necessary to tilt the two mirrors independently. On the other hand, since the tilt in the same direction is sufficient for the vertical direction, it can be dealt with by tilting one of the concave mirrors 31 reflecting the two light beams for the left eye and the right eye.

  As a modification of this embodiment, by providing a biaxial drive unit on the mirrors 8L and 8R, the position of the Eyebox similar to the structure of FIG. 7 can be adjusted. FIG. 9 shows a structure of a head-up display device provided with a biaxial drive unit, which is a modification of the present embodiment.

  As shown in FIG. 9, the configuration of the optical unit using the concave mirror 31 and the convex mirror 32, and the mirrors 8R and 8L and the mirrors 8R and 8L that reflect the light beam projected from the display 1 toward the convex mirror 32 are provided. The drive units 9A and 9B and the rotating shafts 10R and 10L for tilting are the same as the structure in FIG.

  In FIG. 9, the drive unit 9V and the rotating shaft 10V connected to the concave mirror 31 of FIG. 7 are connected to the drive units 9L and 9R that tilt the mirrors 8L and 8R. At this time, the rotary shaft 10V connects the drive units 9L and 9R so that they can be tilted simultaneously. By the drive unit 9V, the drive units 9L and 9R, the rotation shafts 10L and 10R, and the mirrors 8L and 8R are all tilted simultaneously around the rotation shaft 10V. With such a mechanism, the mirrors 8L and 8R can be tilted in two directions, and the position of the Eyebox can be adjusted in the left-right direction and the up-down direction as in the structure of FIG.

  As described above, according to the present embodiment, in the virtual image display device in which the observer visually recognizes a stereoscopic image, the two optical paths of the images projected respectively for the left eye and the right eye are formed by a set of optical systems that do not use an optical lens. It can be realized, and the price of the apparatus can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention described in the claims, and it is also included within the scope of the present invention. Not too long.

DESCRIPTION OF SYMBOLS 1 Display apparatus 1L Video information for left eyes 1R Video information for right eyes 2L Rays of video information for left eyes 2R Rays of video information for right eyes 21L Optical paths for left eyes 21R Optical paths for right eyes 3 Optical units 31, 31L, 31R Concave mirrors 31C Center point of concave mirror 32, 32L, 32R Convex mirror 32C Center point of convex mirror 33L, 34L Reflector for left eye 33R, 34R Reflector for right eye 4 Windshield 5 Observer 5L Left eye 5R Right eye 51 Eye 52, 52L, 52R Eyebox
6 Virtual image 7 Center surface 8L, 8R Mirror 9L, 9R, 9V Drive unit 10L, 10R, 10V Rotating shaft

Claims (4)

In observer virtual image display device capable of binocular stereopsis the image movies,
The left-eye directivity image including the left-eye image information and the right-eye directivity image including the right-eye image information are divided into the left-eye region and the right-eye region , respectively. A display having a projecting projection surface;
A convex mirror that reflects the image for the left eye and the image for the right eye;
A concave mirror that reflects the left-eye image and the right-eye image reflected by the convex mirror ;
When the center points of the respective curvature radii of the convex mirror and the concave mirror are located in a plane that includes the center of the straight line connecting the left eye and the right eye of the observer and is perpendicular to the straight line,
Of the optical path L for the image for the left eye and the optical path R for the image for the right eye that are symmetrical with respect to the vertical plane, the optical path L is in the eye box for the left eye of the left eye of the observer. The left eye eye box and the right eye eye box are separated by projecting an image, and the optical path R projects the right eye image into the right eye eye box of the observer.
Virtual image display device. A mirror for the left eye that reflects the image for the left eye projected from the display toward the convex mirror;
A mirror for the right eye that reflects the image for the right eye projected from the display toward the convex mirror;
The left-eye mirror, the left-eye image within the left-right range of the left-eye eye box, and the right-eye mirror, the right-eye image, the right-eye direction of the right-eye eye box A first drive unit that rotationally drives the left-eye mirror and a first rotation shaft that serves as the center of rotation thereof so that they can be incident independently within the range of
A second drive unit that rotationally drives the right-eye mirror, and a second rotation shaft that serves as the center of rotation;
The concave mirror is rotationally driven so that the left-eye image and the right-eye image can be incident on the left-eye eye box and the right-eye eye box in the vertical range, respectively. A third drive unit and a third rotation shaft serving as the center of rotation thereof;
Further comprising
Wherein the eye box for the left eye eye box for the right eye is moved vertically and horizontally, the virtual image display device according to claim 1 Symbol placement. The concave mirror or the convex mirror is a spherical shape, the virtual image display device of the mounting according to claim 1 or 2 SL. The concave mirror or the convex mirror is an aspheric shape, the virtual image display device of the mounting according to claim 1 or 2 SL.

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