JPWO2018199244A1 - Display system - Google Patents

Abstract

Provided is a display system that easily suppresses an increase in parallax during binocular vision and easily secures a wide viewing angle. A moving object display system (display system) 200 includes an image forming element (drawing device) 11, a display optical system 30 that enlarges a display image formed by the image forming element 11 and displays it as a virtual image, and a viewer's viewpoint. A second arrangement changing device (tilt drive) for tilting a driver (a viewpoint detecting unit) 71 for detecting a position and a mirror (optical member) 17a included in the display optical system 30 in a direction corresponding to a lateral direction of the virtual image IM. The mirror 17a is tilted in the direction corresponding to the lateral direction of the virtual image IM to adjust the posture by operating the second arrangement changing device 62 in accordance with the part) 62 and the viewpoint position obtained by the driver detecting part 71. And control units 18 and 90 for changing the position of the display image.

Description

  The present invention relates to a display system that displays an image as a virtual image ahead of a driver's line of sight.

  A head-up display (hereinafter, also referred to as a HUD (Head-Up Display)) is mounted on, for example, an automobile, and includes a projection optical system that displays an image displayed on a drawing device as a virtual image, and a display screen for displaying the virtual image. Is provided. This HUD allows the driver during driving to check the display without significantly moving his line of sight and viewpoint.

  There is an HUD in which a display position of a virtual image on a combiner can be changed in response to a change in a driver's eye position (Patent Documents 1 and 2). In this case, by changing the position of the projector as a whole or adjusting the vertical inclination of a specific reflector on the optical path, the display position of the virtual image is changed according to the height position of the driver's eyes. Make changes possible.

  However, there is no device that fully considers that the driver's eyes move left and right. In the method of totally changing the position of the projector, the device becomes large regardless of the moving direction of the driver's eyes. Also, in the method of adjusting the inclination of a specific reflecting mirror on the optical path, especially when the driver's eyes move to the left and right ends, the distortion increases, the parallax between both eyes increases, and the driver feels strange. .

JP 2005-247224 A JP 2009-196473 A

  The present invention has been made in view of the above background art, and has as its object to provide a display system that easily suppresses an increase in parallax during binocular vision and easily secures a wide viewing angle.

  In order to achieve at least one of the above objects, a display system that reflects one aspect of the present invention includes a drawing device, and a display optical system that enlarges a display image formed by the drawing device and displays it as a virtual image. A viewpoint detection unit for detecting a viewpoint position of an observer, a tilt drive unit for tilting at least one optical member included in the display optical system in a direction corresponding to a lateral direction of the virtual image, and a viewpoint position obtained by the viewpoint detection unit. And controlling the tilt drive unit to tilt the at least one optical member in a direction corresponding to the lateral direction of the virtual image to adjust the attitude and change the position of the display image.

FIG. 1A is a side sectional view illustrating a display system according to the first embodiment, and FIG. 1B is a front view illustrating the display system from the inside of a vehicle. FIG. 2 is a conceptual enlarged side sectional view illustrating a specific configuration example of an image display device incorporated in a display system. FIG. 3A is a conceptual diagram illustrating a display area in a drawing device, and FIG. 3B is a conceptual diagram illustrating a display area in another state. It is a block diagram explaining the display system for mobiles containing an image display device. FIG. 3 is a diagram conceptually illustrating the operation of the display system. FIG. 5 is a diagram illustrating a modification of the image display device shown in FIG. 2. FIG. 13 is a diagram illustrating another modification of the image display device illustrated in FIG. 2. FIGS. 8A and 8B are conceptual diagrams illustrating the reduction of the mirror size due to the tilt of the mirror and the shift of the display image. FIG. 9 is a diagram illustrating an image display device incorporated in a display system according to a second embodiment. FIG. 11 is a diagram illustrating an image display device incorporated in a display system according to a third embodiment. FIG. 14 is a diagram illustrating an image display device incorporated in a display system according to a fourth embodiment. 12A and 12B are diagrams illustrating a display optical system and the like according to the first embodiment. 13A and 13B are diagrams illustrating a display optical system and the like according to the second embodiment. 14A and 14B are diagrams illustrating a display optical system and the like according to the third embodiment.

[First Embodiment]
Hereinafter, a first embodiment of a display system according to the present invention will be described with reference to the drawings. The display system according to the present embodiment is a display system for a moving object mounted on a vehicle or the like.

  1A and 1B are a schematic side sectional view and a front view illustrating an image display device 100 incorporated in the display system of the present embodiment. The 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 image display device 100 displays image information displayed on the image forming element 11 which is a drawing device in the drawing unit 10 through a display screen 20 for a driver UN as an observer.

  The drawing unit 10 of the image display device 100 is installed so as to be embedded in the dashboard 4 of the vehicle body 2, and emits display light HK corresponding to an image including driving-related information and the like toward the display screen 20. The display screen 20 is a half mirror, also called a combiner, and is a semi-transparent concave mirror or a plane mirror. The display screen 20 is arranged on the opposite side of the image forming element (drawing device) 11, that is, on the downstream side with respect to a projection optical system 17 described later. The display screen 20 is erected on the dashboard 4 by supporting the lower end, and reflects the display light HK from the drawing unit 10 toward the rear of the vehicle body 2. That is, in the case of the drawing, the display screen 20 is an independent type that is installed separately from the 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. The driver UN can observe the display light HK reflected on the display screen 20, that is, the virtual image IM as a projected 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 which is a half mirror, that is, the front view, the real image of the automobile, and the like. As a result, the driver UN observes the virtual image IM as a projection image including driving-related information and the like formed by the reflection of the display light HK on the display screen 20 over the external image behind the display screen 20. be able to.

  As shown in FIG. 2, the drawing unit 10 includes a main body optical system 13 including a virtual image type projection optical system or a reflection optical system including an image forming element 11, a display control unit 18 for operating the main body optical system 13, and And a housing 14 for housing the main body optical system 13 and the like. Of these, a combination of the main optical system 13 and the display screen (combiner) 20 constitutes a display optical system 30. Since the display optical system 30 includes a plurality of optical members, it is easy to project the virtual image IM with less aberration. In FIG. 2 and the like, the origin of the coordinate axis xyz is the center of the eye box corresponding to the position between the pupils HT of the general driver UN, but the origin is shifted for convenience.

  The main body optical system 13 includes, in addition to the image forming element 11 that is a drawing device, a projection optical system 17 that is an enlarging optical system for enlarging and projecting an image formed on the image forming element 11.

  The image forming element 11 is a drawing device having a two-dimensional display surface 11a. The image formed on the display surface 11 a of the image forming element (drawing device) 11 is enlarged by the projection optical system 17 of the main body optical system 13 and guided to the display screen 20. At this time, by using the image forming element 11 capable of two-dimensional display, switching between the display image formed on the display surface 11a and the virtual image IM projected as a result can be made relatively fast. The image forming element 11 can be a liquid crystal panel called an LCD (liquid crystal display) or other transmissive display elements. The image forming element 11 is a reflective display element such as a DMD (Digital Mirror Device) or LCOS (Liquid Crystal On Silicon), a projection optical system for enlarging an image of the reflective display element, and an optical element having a diffusive property. May be used, in which case the optical element having a diffusive property is equivalent to the display surface 11a. Further, instead of the reflection type display element, a scanning type image element utilizing MEMS (Micro Electro Mechanical Systems) can be used.

  The image forming element 11 is driven by the display control unit 18 to perform a display operation. The display surface 11a of the image forming element 11 is partially used, and the display image is displayed in a partial area of the display surface 11a. The image signal from the display control unit 18 is centered on the display image or display area on the display surface 11a in synchronization with or interlocking with the tilt of the optical components constituting the projection optical system 17 according to the viewpoint position of the driver UN described later. Can be appropriately shifted to the periphery. The target of the position change by the display control unit 18 or the like is the display image itself on the image forming element 11. At this time, the image signal from the display control unit 18 can be obtained by correcting the distortion caused by the tilt of the projection optical system 17 itself and the optical components constituting the same. In other words, forcibly applying reverse distortion to a display image formed on the display surface 11a of the image forming element 11, that is, performing distortion correction on the display image, cancels or corrects the distortion of the projected virtual image IM. can do. Accordingly, it is possible to prevent the distortion from fluctuating with the movement of the viewpoint position of the driver UN, and it is possible to display the virtual image IM naturally.

  The image forming element (drawing device) 11 is tiltable, and is driven by a first arrangement changing device 61 which is a tilt correction unit including a rotation mechanism to rotate around a rotation axis RX1 perpendicular to the optical axis AX. Rotate and tilt. That is, the tilt of the image forming element (drawing device) 11 can be adjusted by the first arrangement changing device (tilt correction unit) 61. Here, the rotation axis RX1 for tilting the image forming element 11 extends in a direction parallel to the vertical y direction through an intersection between the display surface 11a of the image forming element 11 and the optical axis AX. Thus, the direction in which the image forming element (drawing device) 11 is tilted corresponds to the lateral direction of the virtual image IM, that is, the direction in which the eyes of the driver UN are lined up. Under the control of the display control unit 18, the first arrangement change device (tilt correction unit) 61 synchronizes or interlocks with a second arrangement change device 62, which will be described later, in accordance with the viewpoint position of the driver UN to operate the image forming element 11. The tilt state is adjusted. The first arrangement changing device 61 can reduce the inclination of the image plane in the horizontal direction and the parallax between both eyes. The first arrangement changing device 61 includes a stepping motor, a DC motor, and the like as actuators.

  The projection optical system 17 enlarges the display image formed on the display surface 11a of the image forming element 11 in cooperation with the display screen 20, and forms a virtual image IM as a projection image in front of the driver UN. The projection optical system 17 includes at least one optical member. In the illustrated example, the projection optical system 17 includes two mirrors 17a and 17b. Here, one of the mirrors (optical member) 17a is a first reflector, which is disposed on the image forming element 11 side in the upstream of the optical path, and serves as a first mirror having optical power. I have. Further, the other mirror (optical member) 17b is disposed on the display screen (combiner) 20 side at the latter stage of the optical path, and serves as a second mirror having optical power.

  The mirror 17a is tiltable, and is rotated around a rotation axis RX2 extending along a yz plane including the optical axis AX by being driven by a second arrangement changing device 62 which is a tilt drive unit including a rotation mechanism. And tilt. That is, the mirror 17a can be adjusted in the tilt state by the second arrangement changing device (tilt driving unit) 62. Here, the rotation axis RX2 for tilting the mirror 17a is on the yz plane including the optical axis AX, and extends in the vertical y-direction through the intersection of the mirror 17a and the optical axis AX or the optical surface origin of the mirror 17a. The direction in which the mirror 17a is tilted corresponds to the horizontal direction of the virtual image IM. That is, there is an effect that the virtual image IM is shifted in the horizontal ± x direction by rotating and tilting the mirror 17a around the rotation axis RX2. If the tilt of the mirror 17a is appropriate, the tilt of the mirror 17a can have an effect of offsetting the operation of moving the line of sight of the driver UN who is the observer in the horizontal direction. The second arrangement changing device 62 includes a stepping motor, a DC motor, and the like as actuators.

  FIG. 3A is a conceptual diagram illustrating a display surface 11 a of the image forming element 11. In the center of the display surface 11a, there is a reference display area AD0, and an area that can be displayed in the ± y direction that is the vertical or vertical direction of the reference display area AD0 remains. In addition, there remains an area that can be displayed in the ± x direction that is the horizontal direction or the horizontal direction of the reference display area AD0. When the mirror 17a is tilted so as to offset the movement of the driver UN's line of sight in the horizontal direction, the display image DM formed in the reference display area AD0 is shifted in the horizontal ± x direction. The operation of shifting the display image DM on the display surface 11a is synchronous or interlocked with the operation of tilting the mirror 17a, and reduces the tilt of the mirror 17a. In this way, by combining the movement of the display image DM on the image forming element 11 and the tilt of the mirror 17a to compensate for each other, the line-of-sight position of the driver UN moves laterally over a wide range. The virtual image IM can be moved so as to cancel the operation, and it is possible to prevent the mirror 17a, 17b or the like from missing the virtual image IM due to the movement of the driver UN's line of sight. That is, the eye box size and the viewing angle can be increased without increasing the size of the projection optical system 17 and the display screen 20 too much. When only the tilt of the mirror 17a is used, it is not easy to increase the viewing angle, and a difference between images of both eyes (hereinafter, referred to as parallax) tends to occur. Even when only the shift of the display image DM is used, it is not easy to increase the viewing angle, and a difference (parallax) between images of both eyes is likely to occur.

  On the display surface 11a of FIG. 3A, shift display areas AD1 and AD2 indicated by dotted lines show an example in which the display image DM is shifted. In this case, in the shift display areas AD1 and AD2, not only the reference display area AD0 is shifted in the ± x direction, but also the reference display area AD0 is slightly shifted in the ± y direction. This takes into consideration that the virtual image IM is shifted not only in the horizontal ± x direction but also in the vertical ± y direction due to the tilt of the mirror 17a. As described above, the display image DM is shifted in the horizontal direction (the horizontal direction and the vertical direction as necessary) on the display surface 11a in accordance with the tilt of the mirror 17a in the horizontal direction. The occurrence of chipping of the IM can be more reliably prevented.

  FIG. 3B shows an example in which the display image DM is shifted up and down. The upper and lower shift display areas AD3 and AD4 are intended to adapt to the vertical line of sight movement of the driver UN to prevent the virtual image IM from being lost. The actual line-of-sight movement of the driver UN is a composite of vertical and horizontal directions, and an image shift is executed by appropriately combining the shift of the display image DM in two intersecting directions shown in FIGS. 3A and 3B.

  FIG. 4 is a block diagram illustrating a display system 200 for a mobile object as a display system according to the embodiment. The display system 200 for a mobile object includes the image display device 100 as a part thereof. The image display device 100 has the structure shown in FIG. 2, and the description is omitted here. The display system 200 for a mobile object illustrated in FIG. 4 is incorporated in a mobile object such as an automobile.

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

  The driver detection unit 71 is a viewpoint detection unit that detects the viewpoint position of the driver UN, and includes a driver seat camera 71a, a driver seat image processing unit 71b, and a 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 the like), and captures images of the head of the driver UN and its surroundings. The driver's seat image processing unit 71b performs various image processing such as brightness correction on an image captured by the driver's seat camera 71a, and facilitates the processing by the determination unit 71c. The determination unit 71c detects the head and eyes of the driver UN by extracting or cutting out the object from the driver's seat image that has passed through the driver's seat image processing unit 71b, and detects the vehicle body from the depth information attached to the driver's seat image. 2, the spatial position of the pupil HT of the driver UN (more specifically, the intermediate position between the two pupils HT) is calculated together with the presence or absence of the head of the driver UN.

  The environment monitoring unit 72 is a unit that identifies a car, a bicycle, a pedestrian, and the like approaching forward, and includes an external camera 72a, an external image processing unit 72b, and a determination unit 72c. The external camera 72a is installed at an appropriate position inside or outside the vehicle body 2, and captures an external image of the driver UN or the front or side of the windshield 8 or the like. The external image processing unit 72b performs various image processing such as brightness correction on an image captured by the external camera 72a, and facilitates the processing by the determining unit 72c. The determination unit 72c detects the presence or absence of an object such as a car, a bicycle, and a pedestrian by extracting or cutting out an object from the external image that has passed through the external image processing unit 72b.

  The main control device 90 controls the operations of the image display device 100, the environment monitoring unit 72, and the like. Specifically, main controller 90 outputs speed and other information related to driving conditions to image display device 100 as image information, and displays virtual image IM including information related to driving conditions on a display screen (combiner). Project over 20. Main controller 90 can also include the presence of an object such as a car, a bicycle, or a pedestrian detected by environment monitor 72 as a warning display in virtual image IM projected by image display device 100. Further, main controller 90 operates image display device 100 in accordance with the viewpoint position of driver UN detected by driver detection unit 71, and adapts virtual image IM projected by image display device 100 to the viewpoint position. Shall be. That is, the main control device 90 operates the second arrangement changing device (tilt driving unit) 62 in accordance with the viewpoint position obtained by the driver detecting unit 71 to move at least one optical member in the vertical direction of the virtual image IM. And the position of the image displayed on the image forming element 11 is changed. Accordingly, it is possible to suppress an increase in the size of the optical member while providing an optical system capable of securing a viewing angle even when the viewpoint position of the driver UN moves significantly in the horizontal and vertical directions. Specifically, the main control device 90 operates the display control unit 18 based on the viewpoint position of the driver UN, and controls the second arrangement changing device (tilt drive unit) 62 to control at least one mirror (optical member) 17a. The posture is adjusted by tilting, and the position of the display image DM is shifted in the image forming element 11.

  Hereinafter, the operations of the display control unit 18 and the main control device 90 related to the first and second arrangement change devices 61 and 62 will be described with reference to FIG. First, main controller 90 detects the position of the eyes of driver UN (that is, the viewpoint position, specifically, the intermediate position of pupil HT) by driver detection unit 71 (step S11). Thereafter, main controller 90 calculates the amount of deviation of the viewpoint position from the origin (center of the eye box) in the x and y directions of the eye position of driver UN obtained in step S11 (step S12). Main controller 90 determines the amount of tilt of mirror 17a based on the amount of deviation of the viewpoint position from the origin, and shifts display image DM on display surface 11a of image forming element 11 in the horizontal and vertical directions. Is determined, the amount of tilt of the image forming element 11 is determined, and the result is output to the display control unit 18 as a signal (step S13). Here, the tilt amount of the mirror 17a includes a tilt direction as a code. The shift amount of the display image DM in the horizontal and vertical directions also includes the shift direction as a code for each of the vertical and horizontal directions. Further, the tilt amount of the image forming element 11 also includes the tilt direction as a code. The tilt amount of the mirror 17a, the shift amount of the display image DM, and the tilt amount of the image forming element 11 may be determined by calculation, but a conversion table may be used. The display control unit 18 adjusts the attitude of the mirror 17a and the image forming element 11 based on a signal from the main control device 90, that is, the tilt amount of the mirror 17a, the shift amount of the display image DM, and the tilt amount of the image forming element 11. At the same time, the position of the display image DM to be displayed on the image forming element 11 is adjusted (step S14). Specifically, the tilt state of the mirror 17a is adjusted via the second arrangement changing device 62, the position of the display image DM on the display surface 11a of the image forming element 11 is adjusted, and the first arrangement changing device 61 is adjusted. Then, the tilt state of the image forming element 11 is adjusted. At this time, the display control unit 18 applies a distortion to the display image DM displayed on the display surface 11a of the image forming element 11, thereby canceling the distortion of the virtual image IM caused by the increase and decrease of the tilt of the mirror 17a. Can also be corrected.

  FIG. 6 shows a modification of the image display device 100 shown in FIG. 2 and the like. In this case, the mirror 17a can be tilted not only in the horizontal direction but also in the vertical direction. Describing the vertical tilt more specifically, the mirror 17a is driven by the second arrangement changing device 62 to rotate and tilt around a rotation axis RX3 extending along the xz plane including the optical axis AX. Here, the rotation axis RX3 for tilting the mirror 17a is on the xz plane including the optical axis AX, and extends in the x direction through the intersection of the mirror 17a and the optical axis AX or the optical surface origin of the mirror 17a. It is orthogonal to the axis RX2.

  As described above, the mirror 17a can be tilted in two orthogonal directions, specifically, in directions corresponding to the horizontal direction and the vertical direction of the virtual image IM, and if the horizontal and vertical tilts of the mirror 17a are appropriate, Such a vertical and horizontal tilt of the mirror 17a can have a function of offsetting a two-dimensional operation in which the line of sight of the driver UN moves in the horizontal and vertical directions. In this case, the vertical shift of the display image DM as shown in FIG. 3B is not essential.

  FIG. 7 shows another modification of the image display device 100 shown in FIG. 2 and the like. In this case, the rotation axis RX2 'for tilting the mirror 17a extends in the tangential direction of the mirror 17a through the intersection between the mirror 17a and the optical axis AX or the origin of the optical surface of the mirror 17a. Also in this case, the virtual image IM is tilted in the horizontal direction or in the horizontal and vertical directions by rotating or tilting the mirror 17a around the rotation axis RX2 'by the second arrangement changing device 62.

  According to the display system or the moving object display system 200 of the first embodiment described above, the main control device 90 and the display control unit 18 as the control units are obtained by the driver detection unit (viewpoint detection unit) 71. By operating the second arrangement changing device (tilt driving unit) 62 according to the viewpoint position, the mirror 17a as at least one optical member is tilted in a direction corresponding to the lateral direction of the virtual image IM, and the posture is adjusted. Since the position of the display image DM in the image forming element 11 is changed, distortion of the virtual image IM can be reduced to suppress an increase in parallax between both eyes, and increase in the size of optical members such as the projection optical system 17 can be suppressed. In addition, it is possible to relatively easily widen the viewing angle of the virtual image IM. In other words, when the viewing angle of the virtual image IM is the same, the size of the optical member can be reduced as compared with the related art, and the volume of the drawing unit 10 can be reduced.

  FIGS. 8A and 8B are conceptual diagrams illustrating the reduction of the mirror size due to the tilt of the mirror 17a and the shift of the display image DM on the image forming element 11. FIG. 8A shows a case where mirror tilt or display image shift is performed, and FIG. 8B shows a case where mirror tilt or display image shift is not performed. In FIG. 8A, the use area EA1 of the mirror 17a when the pupil HT is at the upper right of the eye box and the lower right of the eye box around the use area EA0 of the mirror 17a when the pupil HT is at the center of the eye box. The use area EA2 of the mirror 17a when the pupil HT is present, the use area EA3 of the mirror 17a when the pupil HT is at the upper left of the eye box, and the use area EA4 of the mirror 17a when the pupil HT is at the lower left of the eye box. Are arranged at positions shifted from each other. In the case of FIG. 8A, the shift amount of the use areas EA1 to EA4 when the position of the pupil HT is largely shifted with respect to the basic use area EA0 due to the tilt of the mirror 17a is reduced, and the enlargement of the entire area EA is suppressed. I have. On the other hand, in the case of the comparative example of FIG. 8B, the mirror 17a is fixed, and the shift amount of the use areas EA1 to EA4 when the position of the pupil HT is greatly shifted with respect to the basic use area EA0 is large. Is getting bigger. That is, in the case of FIG. 8A, the entire area EA is considerably narrower than that of FIG. 8B, and the size of the mirror 17a is significantly reduced.

[Second embodiment]
Hereinafter, a display system according to the second embodiment will be described. Note that the display system of the second embodiment is a modification of the display system of the first embodiment, and items that are not particularly described are the same as those of the first embodiment.

  As shown in FIG. 9, in the case of the second embodiment, in the image display device 100, the remaining mirror 17b constituting the projection optical system 17 can also be tilted. The rotation axis RX4 of the mirror 17b is on the yz plane including the optical axis AX, and extends in the z direction through the intersection of the mirror 17b and the optical axis AX or the optical surface origin of the mirror 17b. In this case, the mirror 17b is tilted in the horizontal direction (or the horizontal and vertical directions) based on the virtual image IM by rotating or tilting the mirror 17b around the rotation axis RX4 by the second arrangement changing device 62. become. By tilting the two optical members included in the display optical system 30 in a direction corresponding to the horizontal direction of the virtual image IM, it is possible to suppress an increase in the size of the optical members while further increasing the horizontal viewing angle.

  In the example shown in FIG. 9, the display screen (combiner) 20 can also be tilted. The rotation axis RX5 of the display screen 20 is on the yz plane including the optical axis AX, and extends in the y direction through the intersection of the display screen 20 and the optical axis AX or the optical surface origin of the display screen 20. In this case, the display screen 20 is tilted in the reference horizontal direction (or the horizontal and vertical directions) by rotating or tilting the display screen 20 around the rotation axis RX5 by an arrangement changing device (not shown). Will be.

  In the above, the rotation axis RX4 may extend tangentially through the intersection of the mirror 17b and the optical axis AX. Further, the rotation axis RX5 may also extend tangentially through an intersection between the display screen 20 and the optical axis AX.

  As described above, only the mirror 17b can be tilted without tilting the mirror 17a and the display screen 20. Further, only the display screen 20 can be tilted without tilting the mirrors 17a and 17b.

[Third embodiment]
Hereinafter, a display system according to the third embodiment will be described. Note that the display system of the third embodiment is a modification of the display system of the first embodiment, and items that are not particularly described are the same as those of the first embodiment.

  As shown in FIG. 10, the main optical system (projection optical system) 13 has an imaging optical system 15 between the image forming element 11 and the projection optical system 17. The imaging optical system 15 forms an intermediate image TI obtained by enlarging the image formed on the image forming element 11 on the intermediate screen MS, and the projection optical system 17 cooperates with the display screen 20 to convert the intermediate image TI into a virtual image. Convert to Here, the imaging optical system 15 is a first projection optical system, and the projection optical system 17 is a second projection optical system. The intermediate screen MS is a diffusion plate whose light distribution angle is controlled to a desired angle. As the diffusion plate, for example, ground glass, a lens diffusion plate, a microlens array, or the like is used.

  The image forming element 11 can move the position of the display image DM in the x direction or the y direction on the display surface 11a. As a result, the position of the intermediate image TI on the intermediate screen MS can also be moved in two orthogonal directions such as the x direction and the y direction perpendicular to the optical axis AX. The main control device 90 and the display control unit 18 as the control unit shift the position of the intermediate image TI as the display image according to the viewpoint position obtained by the driver detection unit (viewpoint detection unit) 71. The target of the position change by the display control unit 18 or the like is a display image as the intermediate image TI. At this time, the operation of shifting the intermediate image TI as a display image in the direction perpendicular to the optical axis AX is synchronized or synchronized with the operation of tilting the mirror 17a. When the intermediate screen MS is rotated around the rotation axis RX1 by the first arrangement changing device 61 to tilt the intermediate screen MS with respect to the optical axis AX, the intermediate image TI as a display image also moves with respect to the optical axis AX. To tilt in the horizontal direction.

[Fourth embodiment]
Hereinafter, a display system according to the fourth embodiment will be described. Note that the display system of the fourth embodiment is a modification of the display system of the first embodiment, and items that are not particularly described are the same as those of the first embodiment.

  As shown in FIG. 11, the image forming element 11 is not only rotated and tilted around the rotation axis RX1 by the first arrangement changing device 61, but also driven in the direction parallel to the optical axis AX by the reciprocating drive mechanism 63. Reciprocate to. By moving the image forming element 11 in the optical axis AX direction by the reciprocating drive mechanism 63, the distance between the virtual image IM formed behind the display screen (combiner) 20 by the projection optical system 17 and the driver UN who is the observer. Can be lengthened or shortened. In this way, by changing the position of the virtual image IM to be projected back and forth at a high speed and by changing the display content according to the position, the virtual image IM can be changed while changing the virtual image distance to the virtual image IM. The virtual image IM as a series of projected images can be made three-dimensional. Note that the image forming element 11 operates at a frame rate of 30 fps or more. This makes it easy to make it appear that virtual images IM as a plurality of projection images are displayed simultaneously at different projection distances.

〔Example〕
Hereinafter, specific examples of the display system or the optical system according to the present invention will be described. In the data of the embodiment described below, Si (i = 0, 1, 2, 3,...) Is the i-th surface (the virtual image surface of the virtual image IM is the 0th Surface). The first and second surfaces S1 and S2 following the zeroth surface S0 corresponding to the virtual image surface are virtual surfaces, and the third surface S3 corresponds to the pupil HT.

  The arrangement of each surface Si is specified by surface vertex coordinates (x, y, z) and rotation angles (ADE, BDE). The surface vertex coordinates of each surface Si are determined by using the surface vertex as the origin of the local rectangular coordinate system (X, Y, Z), and using the local rectangular coordinate system (X, y, z) in the local rectangular coordinate system (X, y, z). It is represented by the coordinates (x, y, z) of the origin of (Y, Z) (the unit is mm). The inclination of each surface Si is represented by an ADE or rotation angle (α rotation) about the X axis about the surface vertex and a BDE or rotation angle (β rotation) about the Y axis about the surface vertex. Is represented. The unit of the rotation angle is °. In the case of ADE, the clockwise direction when viewed from the positive direction of the X axis is the positive direction of the rotation angle of α rotation. The clockwise direction is the positive direction of the β rotation angle. The global rectangular coordinate system (x, y, z) is an absolute coordinate system that matches the local rectangular coordinate system (X, Y, Z) of the pupil HT or the pupil plane (S3). That is, the arrangement data of each surface Si is expressed in a global coordinate system with the origin at the center of the pupil plane. In the pupil plane (S3), the direction from the display screen 20, which is a combiner, 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 viewed from the direction from 20 toward the pupil HT is the + X direction or + x direction. That is, the X direction is the x direction shown in FIG. 2 and the like, and the Y direction is the y direction shown in FIG. 2 and the like.

ただし、
ｃ ：頂点曲率（ｃ＝１／Ｒ）
ｋ ：円錐定数
Ｃ_ｊ：Ｘ^ｍＹ^ｎの係数
Ｒ ：Ｙ曲率半径In each embodiment, the fourth surface S4 corresponding to the display screen (combiner) 20 and the surfaces corresponding to the mirrors 17a and 17b (for example, the fifth and sixth surfaces S5 and S6 in the case of the second embodiment) are free-form surfaces. The free-form surface shape is expressed by the following “Formula 1”, where the origin is the vertex of the optical surface, the Z axis is in the optical axis direction, and the sag amount of the surface parallel to the Z axis is Z.
[Equation 1]

However,
c: apex curvature (c = 1 / R)
k: conical constant _C ^j: X m ^Y coefficient ⁿ R: Y radius of curvature

Hereinafter, specific examples of the display system or the display system for a moving object of the present invention will be described.
[Example 1]
Table 1 below shows basic specifications of the display optical system or the projection optical system in the display system of the first embodiment.
[Table 1]

Table 2 below shows data on the optical surface and the like of Example 1.
[Table 2]

Table 3 below shows the surface data of the combiner portion (corresponding to the optical surface on the driver side) of Example 1. In the table, “*” represents a product, and “＾” represents a power (the same applies to the following examples).
[Table 3]

  FIGS. 12A and 12B are side views illustrating the specific arrangement of the optical members constituting the display optical system according to the first embodiment.

表中で、ドライバー位置は、運転者の瞳（間隔７０ｍｍ）の中間位置がアイボックス内で移動した状態における変移量（ｍｍ）を示している。また、表示スクリーン（コンバイナー）のＢＤＥは、表示スクリーンの横回転又はＹ軸回りの回転の角度（°）を示す。表示像のシフト量ｘｄｅ，ｙｄｅの単位はｍｍである。以上は以降の実施例も同様である。Table 4 below shows the amount of tilt of the display screen (combiner) and the amount of shift of the display image adjusted according to the position of the driver.
[Table 4]

In the table, the driver position indicates the amount of displacement (mm) in a state where the intermediate position of the driver's pupil (interval 70 mm) has moved within the eye box. The BDE of the display screen (combiner) indicates the angle (°) of the horizontal rotation of the display screen or the rotation about the Y axis. The unit of the shift amount xde, yde of the display image is mm. The same applies to the following embodiments.

表中の（ａ）欄は、ドライバーの位置（つまり一対の瞳の中間）がアイボックスの中心に位置する場合のコンバイナー使用領域を示し、（ｂ）欄は、チルトタイプの設計で、ドライバーの位置をアイボックス内で限界まで変化させた場合のコンバイナー使用領域を示し、（ｃ）欄は、従来型の通常の設計、つまり非チルトタイプのコンバイナーを用いてドライバーの位置をアイボックス内で限界まで変化させた場合のコンバイナー使用領域を示す。以上は以降の実施例も同様である。Table 5 below describes how to secure a mirror area for securing a virtual image viewing angle regardless of the position of the driver.
[Table 5]

The column (a) in the table shows the use area of the combiner when the position of the driver (that is, the middle of the pair of pupils) is located at the center of the eye box. The column (b) shows a tilt type design, The area where the combiner is used when the position is changed to the limit in the eye box is shown. The column (c) shows the conventional normal design, that is, the position of the driver is limited in the eye box using a non-tilt type combiner. This shows the combiner use area when changed to. The same applies to the following embodiments.

  As is clear from Table 5, (b) area / (a) area is 1.43, (c) area / (a) area is 2.48, and (b) area is (c) It can be seen that 58% of the area is sufficient.

[Example 2]
Table 6 below shows basic specifications of the display optical system or the projection optical system in the display system of the second embodiment.
[Table 6]

Table 7 below shows data on the optical surface and the like of Example 2.
[Table 7]

Table 8 below shows the combiner (corresponding to the driver-side optical surface of the windshield in a car) and the mirror portion of the second embodiment.
[Table 8]

  FIGS. 13A and 13B are side views illustrating a specific arrangement of the optical members constituting the display optical system according to the second embodiment.

Table 9 below shows the amount of tilt of the mirror and the amount of shift of the display image adjusted according to the position of the driver.
[Table 9]

Table 10 below describes the securing of the mirror area for securing the viewing angle of the virtual image regardless of the position of the driver.
[Table 10]

  As is clear from Table 10, (b) area / (a) area is 1.16 for the first mirror (17b), and (b) area / (a) area for the second mirror (17a). (A) The area is 1.11. It can be seen that the use of the tilt type mirror hardly increases the mirror size required for observation at the center of the eye box.

[Example 3]
Table 11 below shows basic specifications of the display optical system or the projection optical system in the display system of the third embodiment.
[Table 11]

Table 12 below shows data on the optical surface and the like of the third embodiment.
[Table 12]

Table 13 below shows the combiner of Example 3 (corresponding to the driver-side optical surface of the windshield in a car) and the mirror surface data.
[Table 13]

  FIGS. 14A and 14B are side views illustrating the specific arrangement of the optical members constituting the display optical system according to the third embodiment.

Table 14 below shows the tilt amount of the mirror and the shift amount of the display image adjusted according to the position of the driver (driver).
[Table 14]

Table 15 below describes the securing of a mirror area for securing the field of view regardless of the position of the driver.
[Table 15]

  As is clear from Table 15, (b) area / (a) area is 147%, and by using the tilt type mirror, the mirror size required for observation at the center of the eye box is hardly increased. It turns out that it is done.

[Others]
In the above, the display system 200 for a mobile body as a specific embodiment has been described, but the display system according to the present invention is not limited to the above. For example, instead of shifting the position of the display image DM on the display surface 11a of the image forming element 11, the display image DM may be shifted by moving the image forming element 11 itself.

  In the above description, the display screen 20 is installed separately from the windshield 8. However, the display screen 20 can be attached to the windshield 8 as a sheet, and the display screen 20 can be embedded in the windshield 8. it can. In this case, the display screen 20 cannot be tilted, and the optical member constituting the projection optical system 17 is displaced.

  The image display device 100 can be arranged upside down so that the display screen 20 can be disposed above the windshield 8 or at the sun visor position. In this case, the display screen 20 is positioned obliquely downward and forward of the drawing unit 10. Be placed.

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

  In the above embodiment, the optical surface of the display screen or the mirror is a free-form surface having symmetry. However, the present invention is not limited to this, and a free-form surface having no symmetry may be used.

  In the above embodiment, the mirror performs the α rotation and the β rotation about the optical surface origin as the rotation center. However, the present invention is not limited to this, and the rotation center may be different from the optical surface origin.

  The first arrangement changing device (tilt correction unit) 61 is not essential, and can be configured so as not to mechanically displace the image forming element 11. Further, the first arrangement changing device (tilt correction unit) 61 can tilt the image forming element 11 not only in the horizontal direction but also in the vertical direction.

  The imaging optical system 15 and the projection optical system 17 shown in FIG. 2 and the like are merely examples, and the optical configurations of the imaging optical system 15 and the projection optical system 17 can be appropriately changed.

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

Claims (9)

A drawing device,
A display optical system for enlarging a display image formed by the drawing device and displaying it as a virtual image,
A viewpoint detection unit that detects a viewpoint position of an observer,
A tilt drive unit that tilts at least one optical member included in the display optical system in a direction corresponding to a lateral direction of the virtual image;
According to the viewpoint position obtained by the viewpoint detection unit, the tilt drive unit is operated to tilt the at least one optical member in a direction corresponding to a lateral direction of the virtual image, thereby adjusting a posture, and displaying the display image. And a control unit for changing the position of the display. The tilt drive unit tilts the at least one optical member or another optical member included in the display optical system in a direction corresponding to a vertical direction of a virtual image,
The control unit operates the tilt drive unit according to a viewpoint position obtained by the viewpoint detection unit to tilt the at least one optical member or the other optical system in a direction corresponding to a vertical direction of a virtual image. The display system according to claim 1, wherein a position of an image to be displayed on the drawing device is changed at the same time.   The display system according to claim 1, wherein the control unit causes the drawing device to display a display image on which distortion correction has been performed, according to a viewpoint position obtained by the viewpoint detection unit.   The display system according to claim 1, wherein the control unit changes a position of the display image displayed on the drawing device according to a viewpoint position obtained by the viewpoint detection unit. The display optical system includes a first projection optical system that forms an intermediate image from an image of the drawing device, and a second projection optical system that projects the intermediate image as a virtual image,
The display system according to claim 1, wherein the control unit changes a position of the intermediate image corresponding to a position of the display image according to a viewpoint position obtained by the viewpoint detection unit.   The display system according to claim 1, wherein the display optical system includes a plurality of optical members.   The display system according to claim 6, wherein the tilt drive unit tilts two optical members included in the display optical system in a direction corresponding to a lateral direction of a virtual image.   The display system according to claim 1, further comprising a tilt correction unit that tilts a display image formed by the drawing device in a direction corresponding to a horizontal direction of the virtual image.   The said display optical system is provided with the projection optical system arrange | positioned at the optical path upstream side, and the translucent display screen arrange | positioned at the opposite side of the said drawing device with respect to the said projection optical system. The display system according to any one of the preceding claims.

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