WO2020080007A1

WO2020080007A1 - Display apparatus

Info

Publication number: WO2020080007A1
Application number: PCT/JP2019/036049
Authority: WO
Inventors: 菅原和弘; 山田範秀; 関口瑛士
Original assignee: コニカミノルタ株式会社
Priority date: 2018-10-15
Filing date: 2019-09-13
Publication date: 2020-04-23
Also published as: JPWO2020080007A1

Abstract

An image display apparatus (100) as a display apparatus is provided with a drawing device (11), a projection optical system (15) for magnifying an image formed by the drawing device (11), an intermediate screen (19) which has a diffusing function and is disposed on the light emission side of the projection optical system (15), a magnifying projection optical system (17) for converting the image on the intermediate screen (19) to a virtual image, a rotary drive unit (64) as an arrangement changing device for varying the position of the intermediate screen (19) along the optical axis AX direction, a position detection element (65) for detecting the position of the intermediate screen (19), and a display control unit (18) for controlling at least one of the operation of the intermediate screen (19) and the operation of the drawing device (11) on the basis of position information of the intermediate screen (19) obtained from the position detection element (65) and information relating to the light emission timing of the drawing device (11), the drawing device (11) drawing R, G, and B images constituting a color image at the timing at which the intermediate screen (19) is disposed in a predetermined position.

Description

Display device

The present invention relates to a display device in which a virtual image is displayed in front of the line of sight and the projection position of the virtual image is variable.

Conventional head-up display (HUD) devices generally generate a virtual image at a position away from the driver by a certain distance, and the distance from the driver to the virtual image is constant. When the position of the eyes is displaced, the position of the object and the position of the danger signal (virtual image) are displaced, and there is a problem that the driver mistakenly recognizes the object. As a method for solving such a problem, it is conceivable to superimpose a virtual image on the object including the depth direction. The HUD device having such a configuration draws RGB color image data in a time-sequential manner by the drawing device, and when the intermediate screen is arranged at a predetermined position, pulse-projects the RGB image, resulting in A target color image (virtual image) is projected on a predetermined virtual image distance. At this time, it is necessary to synchronize the movement of the intermediate screen with the light emission timing of the drawing device.

Here, as a method of providing a virtual image with depth, there is a method described in Patent Document 1 below. In Patent Document 1, scanning type image forming means such as a MEMS mirror, an intermediate screen, a projection means, and a movable means for changing the intermediate screen position are provided, and the position of the virtual image is changed by changing the intermediate screen position. It is changing. The main purpose of Patent Document 1 is to reduce the line-of-sight of the driver by moving the virtual image position closer or further away in view of the fact that the distance the human gazes changes depending on the speed of the vehicle. There is no description about the synchronization between the movement of the light source and the light emission timing of the drawing device.

Japanese Patent Laid-Open No. 2018-45103

The present invention has been made in view of the background art described above, and an object of the present invention is to provide a display device capable of displaying virtual images at a plurality of distances by adjusting operations of a drawing device and an intermediate screen.

In order to achieve at least one of the above-mentioned objects, a display device that reflects one aspect of the present invention has a drawing device, a projection optical system that magnifies an image formed on the drawing device, and a diffusion function. An intermediate screen arranged on the light exit side of the projection optical system, a magnifying projection optical system for converting an image on the intermediate screen into a virtual image, and a position changing device for changing the position of the intermediate screen along the optical axis direction, Based on the position detection element that detects the position of the intermediate screen, the position information of the intermediate screen obtained from the position detection element, and the information regarding the light emission timing of the drawing device, at least one of the operation of the intermediate screen and the operation of the drawing device is performed. The rendering device includes a display control unit for controlling, and the drawing device configures R and G that form a color image at a timing when the intermediate screen is arranged at a predetermined position. And draws an image of B.

FIG. 1A is a side sectional view showing a state in which the image display device of the first embodiment is mounted on a vehicle body, and FIG. 1B is a front view from the inside of the vehicle for explaining the image display device. It is an expanded side sectional view explaining a concrete example of composition, such as a virtual image display optical system. It is a conceptual diagram explaining the structure of a drawing device. 4A and 4B are a plan view and a side sectional view for explaining the structure of a diffusion unit incorporating the intermediate screen, and FIG. 4C is a diagram for explaining movement of the functional region and the like accompanying the rotation of the intermediate screen. It is a figure which illustrates the change of the position of an intermediate image concretely. It is a block diagram explaining the display system for mobiles containing an image display device. It is a figure explaining the operation example of an image display device. FIG. 8A is a diagram for explaining a rotation signal received by the position detection element, and FIGS. 8B and 8C are diagrams for explaining a light emission timing of the drawing device. It is a perspective view explaining a concrete display state. 10A is a diagram corresponding to FIG. 5, and FIGS. 10B to 10D are diagrams corresponding to the display image or frame frame in FIG. 9. It is a figure explaining the operation example of the image display device of a 2nd embodiment. It is a figure explaining the operation example of the image display device of a 3rd embodiment.

[First Embodiment]
Hereinafter, the image display device which is the first embodiment of the display device according to the present invention will be specifically described.

1A and 1B are a conceptual side sectional view and a front view illustrating an image display device 100 as a display device and a usage state thereof. The image display device 100 is mounted in the vehicle body 2 as a head-up display (HUD) device, for example, and includes a drawing unit 10 and a display screen 20. The image display device 100 displays image information displayed on a later-described drawing device 11 in the drawing unit 10 as a virtual image toward the driver UN via the display screen 20.

The drawing unit 10 of the image display device 100 is installed in the dashboard 4 of the vehicle body 2 so as to be embedded behind the display 50, and displays the display light HK corresponding to an image including driving-related information and the like on the display screen. Eject toward 20. The display screen 20 is also called a combiner, and is a semi-transparent concave mirror or a plane mirror. The display screen 20 is erected on the dashboard 4 by being supported at its 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 illustrated case, the display screen 20 is an independent type installed separately from the front window 8. The display light HK reflected by the display screen 20 is guided to an eye box (not shown) corresponding to the pupil HT of the driver UN sitting in the driver's seat 3 and its peripheral position. The driver UN can observe the display light HK reflected by the display screen 20, that is, the display image IM as a virtual image in front of the vehicle body 2. On the other hand, the driver UN can observe external light transmitted through the display screen 20, that is, a front view, a real image of an automobile or the like. As a result, the driver UN has a display image (virtual image) IM that includes driving-related information and the like formed by reflection of the display light HK on the display screen 20 so as to be superimposed on the outside image or the see-through image behind the display screen 20. Can be observed.

Here, although the display screen 20 is configured separately from the front window 8, the front window 8 is used as a display screen and projection is performed on the display range set in the front window 8 so that the driver UN displays a display image. The IM may be observed. At this time, the reflection area can be secured by changing the reflectance of a part of the glass of the front window 8 with a coat or the like. Further, when the reflection angle at the front window 8 is, for example, about 60 degrees, the reflectance is secured at about 15%, and it can be used as a reflective surface having transmissivity without providing a coat. Alternatively, the display screen 20 may be sandwiched between the windows of the front window 8.

As shown in FIG. 2, the drawing unit 10 includes a main body optical system 13 which is a virtual image type magnifying and imaging system including a drawing device 11, a display controller 18 for operating the main body optical system 13, a main body optical system 13 and the like. And a housing 14 for housing the. The display control unit 18 controls the emission timing of the drawing device 11, the emission colors of RGB, and the emission amount. A combination of the main body optical system 13 and the display screen 20 constitutes a virtual image display optical system 30.

The main body optical system 13 includes, in addition to the drawing device 11, a projection optical system 15 for forming an intermediate image TI in which an image formed on the drawing device 11 is magnified, and a projected image forming position of the intermediate image TI or its vicinity ( In the following description, the diffusion unit 16 disposed at the image formation position) and the image on the diffusion unit 16 (the intermediate image TI itself, as well as the image that is slightly out of focus due to the positional deviation from the intermediate image TI) And an enlarged projection optical system 17 for enlarging the intermediate image TI ′.

The drawing device 11 has a two-dimensional display surface 11a. The image formed on the display surface 11 a of the drawing device 11 is enlarged by the projection optical system 15 of the main body optical system 13 and projected on the diffusion unit 16. At this time, since the projection optical system 15 magnifies the image formed on the display surface 11a of the drawing device 11 by using the drawing device 11 capable of two-dimensional display, a display displayed as a virtual image through the display screen 20. The image IM can be switched at a relatively high speed. The operation of the drawing device 11 is controlled by the display control unit 18 described later so as to be synchronized with the operation of the rotation drive unit 64 attached to the diffusion unit 16. The drawing device 11 includes, for example, a reflective display element. A semiconductor light source, for example, is used as the light emitting body that illuminates the display element. When changing the virtual image distance, the drawing device 11 operates at a frame rate of 30 fps or more, and more preferably 60 fps or more for each virtual image distance. Thereby, it becomes easy to make a plurality of display images (virtual images) IM at different virtual image distances appear to be displayed to the driver UN at the same time.

FIG. 3 is a diagram illustrating a specific configuration of the drawing device 11. The drawing device 11 includes an illumination optical system 5 that emits illumination light, and a display device 6 that generates an image by two-dimensional spatial modulation of the illumination light. The illumination optical system 5 includes three

light sources

4a, 4b, 4c for emitting illumination light, a first dichroic mirror 5a, a second dichroic mirror 5b,

collimators

5d, 5e, 5f, a relay lens 5h, and a fly. An eye optical system 5j,

condenser lenses

5m and 5n, a bending mirror 5p, a TIR (Total Internal Reflection) prism 5q, and a flat plate 5r are provided. The three

light sources

4a, 4b, 4c are light emitting elements such as LEDs (light emitting diodes), and emit the illumination light La, Lb, Lc of three colors of R, G, and B, respectively. The light source 4a is an R light source, the light source 4b is a G light source, and the light source 4c is a B light source. The first dichroic mirror 5a combines the G illumination light Lb from the second light source (G light source) 4b and the B illumination light Lc from the third light source (B light source) 4c to form a second dichroic mirror. 5b synthesizes the R illumination light La from the first light source (R light source) 4a and the G and B illumination lights Lb and Lc synthesized by the first dichroic mirror 5a. The

collimators

5d, 5e, 5f bring the illumination lights La, Lb, Lc from the

respective light sources

4a, 4b, 4c into a state close to parallel light flux. The relay lens 5h has a role of compensating for the optical path difference on the illumination light Lb, Lc side. The fly-eye optical system 5j is also called an optical integrator, and uniformizes the illumination light La, Lb, Lc from the

light sources

4a, 4b, 4c. The

condenser lenses

5m and 5n cause the La, Lb, and Lc that have passed through the fly-eye optical system 5j to enter the display device 6 within an appropriate incident angle range. The TIR prism 5q separates the optical paths of the illumination light La, Lb, and Lc from the optical path of the display light HK by utilizing the presence or absence of total reflection. Specifically, the illumination light can be guided to the display device 6 from a direction tilted with respect to the optical axis AX of the projection optical system 15 by totally reflecting the illumination light on the inclined surface 5w of one prism constituting the TIR prism 5q. Therefore, the light from the display device 6 can be transmitted in the front direction along the optical axis AX of the projection optical system 15 and incident on the projection optical system 15 as the display light HK. The flat plate 5r is a cover glass of the display device 6, but it may have a filter function.

The display device 6 is a digital mirror device (DMD), which turns on the illumination light incident from the TIR prism 5q toward the projection optical system 15 through the TIR prism 5q or diverts it from the projection optical system 15.・ Off operation is possible. The operation of the display device 6 is synchronized with the

light sources

4a, 4b, and 4c that sequentially emit light, and the display lights HK of three colors of R, G, and B are sequentially or simultaneously formed.

Returning to FIG. 2, the projection optical system 15 is a fixed focus lens system and has a plurality of lens elements. The projection optical system 15 magnifies and projects the image formed on the display surface 11a of the drawing device 11 as an intermediate image TI or a forced intermediate image TI 'onto the diffusion unit 16 at an appropriate magnification.

The diffusing unit 16 is a member arranged at a projection position or an image forming position of the projection optical system 15 (that is, a planned image forming position of the intermediate image TI or in the vicinity thereof), and is driven by a rotation driving unit 64 which is an arrangement changing device. Then, for example, it rotates around the reference axis SX at a constant speed. That is, the rotation drive unit 64 causes the diffusion unit 16 (specifically, the intermediate screen 19 of the rotating body 16a described later) to perform periodic motion within the movable range along the optical axis AX direction. Further, the rotation driving unit 64 operates under the control of the display control unit 18, and based on the placement detection result of the intermediate screen 19 by the position detection element 65, the drawing device 11 with respect to the rotation position and the rotation speed of the intermediate screen 19. The projection timing of is adjusted.

As shown in FIGS. 4A and 4B, the diffusing unit 16 incorporated in the image display device 100 includes a spiral rotating body 16a having a contour close to a disc as a whole, and a central shaft portion 16r supporting the rotating body 16a. Have.

The rotating body 16a has a central portion 16c and an outer peripheral optical portion 16p. One surface 16f (in the present embodiment, the projection optical system 15 side or the + Y side surface) formed on the outer peripheral optical portion 16p of the rotating body 16a is formed as a smooth surface or an optical surface, and on the surface 16f. Has an intermediate screen 19 formed over the entire area.

The intermediate screen 19 is an annular diffusion plate whose light distribution angle is controlled to a desired angle. The intermediate screen 19 may be a sheet attached to the rotating body 16a, but may be a fine concavo-convex pattern formed on the surface of the rotating body 16a. Further, the intermediate screen 19 may be formed so as to be embedded inside the rotating body 16a. The intermediate screen 19 forms the intermediate image TI or the forced intermediate image TI ′ by diffusing the incident display light HK (see FIG. 2).

The other surface 16s (a surface on the side of the magnifying projection optical system 17 in this embodiment) formed on the outer peripheral optical part 16p of the rotating body 16a is formed as a smooth surface or an optical surface. The rotator 16a is a light-transmissive spiral member, and the pair of

surfaces

16f and 16s are spiral surfaces having the reference axis SX as the spiral axis. As a result, the intermediate screen 19 formed on the one surface 16f is formed in the range of one pitch of the spiral. A step-like boundary portion 16j is formed at one location along the circumference of the diffusion portion 16, and this boundary portion 16j has a distance step of, for example, 30 mm or less in the optical axis AX direction or the reference axis SX direction at a position corresponding to the spiral end. Or, it gives a pitch. The boundary 16j of the diffusion unit 16 is also the boundary of the intermediate screen 19. The boundary portion 16j connects a step between the spiral ends and has a strip-shaped connecting surface 16k that is inclined with respect to a plane including the reference axis SX that rotates the diffusion portion 16. As described above, since the pair of

surfaces

16f and 16s of the rotating body 16a are spiral surfaces having the reference axis SX as the spiral axis, the rotating body 16a has a substantially equal thickness t with respect to the reference axis SX or the optical axis AX direction. Have.

As shown in FIG. 4A, in the rotating body 16a, one location along the circumferential direction is a functional area FA through which the optical axis AX of the main body optical system 13 passes, and an intermediate screen 19 in the functional area FA provides an intermediate area. An image TI is formed. The functional area FA moves at a constant speed on the rotating body 16a as the rotating body 16a rotates, and orbits on the rotating body 16a (see FIG. 4C). In the illustrated example, since the intermediate screen 19 is formed in the range corresponding to one cycle of the spiral, the intermediate screen 19 spatially moves by one rotation of the rotating body 16a, and the functional area FA or the intermediate area of the intermediate screen 19 is increased. The image TI moves in the optical axis AX direction by a distance D corresponding to a step (see FIG. 4B).

Note that the projection optical system 15 has a predetermined depth of focus that is equal to or larger than the moving range of the functional area FA so that defocusing does not occur depending on the position of the intermediate screen 19 provided in the diffusion unit 16.

The position detection element 65 detects the position of the intermediate screen 19, and is provided at the intermediate screen 19 or a detectable position of the intermediate screen 19. Here, the detectable position of the intermediate screen 19 means, for example, a region near the intermediate screen 19 in which the operation of the intermediate screen 19 can be recognized. Thereby, the position of the intermediate screen 19 can be detected more accurately. As the position detecting element 65, for example, a photo interrupter, a hall element, a rotary encoder, or the like is used. FIG. 2 shows an example in which the position detection element 65 is a photo interrupter. Although not shown, the photo interrupter includes a light emitting unit and a light receiving unit. In the illustrated example, the position detecting element 65 is provided near the outer peripheral portion of the rotating body 16a, and the reflecting member 66 having a different reflectance is provided at one location on the outer peripheral portion of the rotating body 16a. The reflecting member 66 reflects the light emitted from the light emitting portion of the position detecting element 65 toward the light receiving portion of the position detecting element 65 once per revolution of the rotating body 16 a. The rotation speed of the rotating body 16a is measured by the timing of light emission from the light emitting portion and the timing of light reception at the light receiving portion of the position detection element 65, and as a result, the rotation angle and rotation position of the intermediate screen 19 are measured. Position information such as (including the position of the functional area FA in the optical axis AX direction) can be obtained. In addition, in order to improve the accuracy of position detection, a plurality of reflecting members 66 may be provided on the rotating body 16a.

Returning to FIG. 2, the magnifying projection optical system 17 magnifies the intermediate image TI formed on the diffusing section 16 in cooperation with the display screen 20, and displays it as a virtual image through the display screen 20 in front of the driver UN. Form the image IM. The magnifying projection optical system 17 includes at least one mirror, but includes two

mirrors

17a and 17b in the illustrated example.

In the image display device 100 shown in FIG. 2 and the like, by operating the rotation driving unit 64 under the control of the display control unit 18, the diffusing unit 16 rotates around the reference axis SX, and the rotating body 16a or the intermediate screen 19 moves. The position intersecting the optical axis AX (that is, the functional area FA) also moves in the optical axis AX direction. That is, for example, as shown in FIG. 4C, the functional area FA on the intermediate screen 19 is adjacent to the functional area FA1 that is set at a position deviated from the original functional area FA1 by an equal angle as the rotary body 16a rotates. FA2 and FA3 are sequentially shifted to move in the optical axis AX direction. By moving the functional area FA in the optical axis AX direction, the position of the intermediate image TI can also be moved in the optical axis AX direction. By rotating the diffusing section 16 around the reference axis SX, the position of the intermediate image TI corresponding to the functional area FA repeatedly and cyclically moves in the optical axis AX direction, and the magnifying projection optical system 17 is provided behind the display screen 20. It is possible to increase or decrease the distance between the display image IM as a virtual image formed in the above and the driver UN who is the observer. In this way, under the control of the display control unit 18, the position of the projected display image IM is changed back and forth, and the display content by the drawing device 11 is adapted to the position, so that the display image IM is displayed. Since the display content of the display image IM is changed while changing the projection distance or the virtual image distance of the display image IM, the display image IM as a series of projection images can be three-dimensional.

In the present embodiment, the image display device 100 is capable of displaying the display image IM at a plurality of virtual image distances, and in the functional area FA of the rotator 16a, R forming each color image corresponding to the display image IM. , G, and B images are projected. Since the rotating body 16a is rotating when the image is projected, the R, G, and B images are sequentially projected onto the corresponding regions of the rotating body 16a. If the R, G, and B images corresponding to one color image are projected on the area where the positions of the intermediate screen 19 provided on the rotating body 16a in the optical axis AX direction are substantially the same, a predetermined virtual image distance is obtained. A corresponding color image that is the display image IM is displayed. The functional area FA moves at a constant speed on the rotating body 16a as the rotating body 16a rotates. In the illustrated example, if images of R, G, and B forming a color image are sequentially projected onto the functional area FA within the area where the positions on the optical axis AX are substantially the same, as a result, R, G, and B Virtual composite functional areas corresponding to a color image in which images are composited are discretely provided, and a virtual image is displayed in discrete distance zones.

FIG. 5 is a diagram specifically illustrating a change in the position of the intermediate image TI due to the rotation of the diffusion unit 16. The center of the functional area FA of the diffusing section 16 repeatedly moves cyclically along the optical axis AX in a sawtooth temporal pattern PA, and the drawing device 11 continuously displays the center position of the intermediate image TI. In this case, as shown in the drawing, the pattern moves repeatedly along the optical axis AX in a sawtooth pattern with time. That is, the position of the intermediate image TI is discontinuous at the location corresponding to the boundary portion 16j, but continuously and periodically changes with the rotation of the diffusion unit 16. As a result, although not shown, the position of the display image (virtual image) IM is also different in scale, but similarly to the position of the intermediate image TI, the position of the display image IM repeatedly moves periodically along the optical axis AX to continuously project the projection distance. Can be changed. Since the drawing device 11 does not perform continuous display but performs intermittent display while switching display contents, the display position of the intermediate image TI is also a discrete position on the sawtooth temporal pattern PA. Become. In the temporal pattern PA, the display position Pn closest to the close-up side or the magnifying projection optical system 17 and the display position Pf farthest away from the projection optical system 15 are set at both ends of the temporal pattern PA. Further, the discontinuity PD of the temporal pattern PA corresponds to the boundary portion 16j provided on the rotating body 16a of the diffusion unit 16. Further, the centers of the functional areas FA1, FA2, FA3 shown in FIG. 4C correspond to the discrete display positions P1, P2, P3 on the temporal pattern PA.

FIG. 6 is a block diagram illustrating the mobile display system 200, and the mobile display system 200 includes the image display device 100 as a part thereof. This image display device 100 has the structure shown in FIG. 2, and a description thereof will be omitted here. The moving body display system 200 is incorporated in a moving body such as an automobile.

The mobile display system 200 includes an environment monitor 72 and a main controller 90 in addition to the image display device 100. The display system 200 for a mobile body of the present embodiment includes a PID control unit 81 and the like to be described later, so that feedback control of the operation of the image display device 100 is possible.

The environment monitoring section 72 is a section for identifying a vehicle, a bicycle, a pedestrian, etc., which are in the vicinity of the front, and includes an external camera 72a, an external image processing section 72b, and a determination section 72c. The external camera 72a is installed in a proper place inside and outside the vehicle body 2 and captures an external image of the front side or the side of the driver UN or the front window 8. The external image processing unit 72b facilitates the processing in the determination unit 72c by performing various image processing such as brightness correction on the image captured by the external camera 72a. The determination unit 72c detects the presence or absence of an object such as a car, a bicycle, or a pedestrian by extracting or cutting out an object from the external image that has passed through the external image processing unit 72b, and determines from the depth information that accompanies the external image. The spatial position of the object in front of the vehicle body 2 is calculated.

Although not shown, the external camera 72a is, for example, a compound eye type three-dimensional camera. In other words, the external camera 72a is an array of camera elements each including a lens for image formation and a CMOS or other image pickup element arranged in a matrix, and each has a drive circuit for the image pickup element. The plurality of camera elements that form the external camera 72a are configured to focus at different positions in the depth direction, or to detect relative parallax, for example. By analyzing the state (focus state, object position, etc.), the distance to each region or object in the image can be determined.

Even when a combination of a two-dimensional camera and an infrared distance sensor is used instead of the compound-eye type external camera 72a as described above, each part (area or object) in the captured screen is displayed in the depth direction. Distance information can be obtained. Further, instead of the compound-eye type external camera 72a, a stereo camera in which two two-dimensional cameras are separately arranged can obtain distance information in the depth direction with respect to each part (area or object) in the captured image. In addition, by using a single two-dimensional camera to perform imaging while changing the focal length at high speed, it is possible to obtain distance information in the depth direction with respect to each part (region or object) in the captured screen.

The display control unit 18 operates the virtual image display optical system 30 under the control of the main controller 90 to display a three-dimensional display image IM with a virtual image distance changing behind the display screen 20. The display image IM is a mark such as a frame frame HW (see FIG. 9) located in the periphery in the depth direction or the like of an object such as a car, a bicycle, a pedestrian or the like which exists behind the display screen 20. can do.

The display control unit 18 includes a PID (Proportional-Integral-Differential) control unit 81 that performs feedback control, and a servo mechanism 82. The PID control unit 81 operates the servo mechanism 82 under the control of the main controller 90, and mainly performs feedback control of the operation of the drawing device 11 and the operation of the intermediate screen 19. Here, the feedback means that, with respect to the operation of the intermediate screen 19 and the operation of the drawing device 11, the output timing of the drive signal is corrected so as to cancel the deviation from the target value of these operations. . The servo mechanism 82 controls the light emission timing of the drawing device 11, the rotation speed or the rotation speed of the rotating body 16a, and the like so that the light emission timing of the drawing device 11 reaches the set value via the PID control unit 81. . The drawing device 11 emits light from the light source at a drawing speed of several thousand times per second, and the intermediate screen 19 of the diffusion unit 16 moves at a periodic speed of 40 rps to 60 rps. In order to draw an image corresponding to the drawing device 11 when the intermediate screen 19 is present at a predetermined position, it is necessary to perform the above feedback control and synchronize the two with high accuracy.

The display control unit 18 changes the arrangement so that the movement timing of the intermediate screen 19 and the light emission timing of the drawing device 11 have a predetermined synchronization relationship based on the position information of the intermediate screen 19 and the information about the light emission timing of the drawing device 11. At least one of the rotation driving unit 64, which is a device, and the drawing device 11 is controlled. That is, the display control unit 18 determines the movement timing of the intermediate screen 19 and the light emission timing of the drawing device 11 based on the position information of the intermediate screen 19 obtained from the position detection element 65 and the information regarding the light emission timing of the drawing device 11. Control at least one. Further, the main controller 90 acquires the position information of the intermediate screen 19 from the position detection element 65 in real time, and acquires the light emission timing of the drawing device 11 in real time. The light emission timing of the drawing device 11 may be set in advance or may be acquired by directly detecting the projection light of the drawing device 11. The drawing device 11 draws R, G, and B images that form a color image at the timing when the intermediate screen 19 is arranged at a predetermined position.

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

Hereinafter, a method of synchronizing the operation of the intermediate screen 19 and the operation of the drawing device 11 will be described. The image display apparatus 100 controls the drawing device 11 by using the pulse of the rotation signal of the rotating body 16a as a trigger. Thus, the drawing device 11 can be controlled according to the rotation of the rotating body 16a.

As shown in FIG. 7, first, under the control of the display control unit 18, the rotating body 16a is operated at a predetermined rotation speed using the rotation drive unit 64, and the intermediate screen 19 is moved along the optical axis AX. Further, the drawing device 11 is operated at a predetermined light emission timing and light emission time under the control of the display control unit 18 (step S11).

Next, the position of the intermediate screen 19 is detected (step S12). A rotation signal accompanying the rotation of the rotating body 16a is obtained as a pulse signal of the position detection element 65. 8A to 8C are diagrams for explaining the relationship between the rotation signal and the light emission timing of the drawing device 11. In FIG. 8A, symbols T1 and T2 respectively indicate rotation signals corresponding to the light detected by the position detection element 65 at the first rotation and the second rotation of the rotating body 16a. Further, in FIGS. 8B and 8C, the lighting signal of the drawing device 11 actually shows a plurality of R, G, and B emission pulses as one pulse for convenience. Here, if the rotation speed of the rotating body 16a is fixed and the rotation speed or the rotation angle of the rotating body 16a is measured by the position detecting element 65, the position information of the intermediate screen 19 can be obtained.

Next, the light emission timing and light emission time of the drawing device 11 operated by the display control unit 18 are acquired (step S13). Information such as the light emission timing of the drawing device 11 may be set in advance, or may be measured using a sensor or the like separately.

Next, under the control of the display control unit 18, the drawing device 11 is operated at the predetermined light emission timing and light emission time which are fed back (step S14). Specifically, under the control of the display control unit 18, the PID control unit 81 and the servo mechanism 82 feed back the light emission timing of the drawing device 11 and the position information of the intermediate screen 19, and the light emission timing and the light emission time of the drawing device 11 are fed back. To adjust the operation of the drawing device 11 with respect to the operation of the intermediate screen 19. Thereby, the operation of the drawing device 11 can be adjusted in consideration of the operation that acts on the intermediate screen 19. In the feedback, the display control unit 18 determines whether or not the light emission in the drawing device 11 corresponding to the lighting signal of the drawing device 11 is performed a predetermined number of times in one cycle of the rotating body 16a or the intermediate screen 19. The delay of the rotation speed and the rotation position of the intermediate screen 19 is calculated from the deviation from the target value and corrected. When the rotation speed of the intermediate screen 19 is delayed from the target value, the light emission timing of the drawing device 11 is delayed by the delay time. Further, the delay of the light emission timing of the drawing device 11 is also calculated and corrected from the deviation from the target value. When the light emission timing of the drawing device is delayed from the target value, the light emission timing of the drawing device 11 is advanced by the delay time. The correction by feedback may be reflected in the first cycle or in the second and subsequent cycles. In the drawing device 11, if there is a time lag between the drive signal in the driver circuit that drives the drawing device 11 and the light emission in the display device 6, the feedback is performed by taking into account, for example, the predicted delay time.

By synchronizing the timing of the rotation signal and the lighting signal, it is possible to display the virtual image and the object superimposed at the correct position without time delay. If the position of the intermediate screen 19 can be discriminated, the pulse of the rotation signal can be used as a trigger to generate the light emission pulse (lighting signal) of the drawing device 11 at an appropriate timing. As a result, the frame rate including the R, G, and B images of the drawing device 11 is adjusted, and the color image corresponding to the position of the intermediate screen 19 is displayed as a virtual image. This allows the driver UN to visually recognize the virtual images simultaneously displayed at different virtual image distances. Further, if the drawing device 11 is caused to emit light at a timing corresponding to only one virtual image distance, it is possible to allow the driver UN to visually recognize only the virtual image at the single virtual image distance.

The main controller 90 confirms whether or not the display is continued (step S15), and when the display is continued (Y in step S15), the process returns to step S11 and the processes of step S12 and the like are repeated. It is preferable that the feedback in step S14 is always performed. Further, steps S12 and S13 may be performed in reverse or simultaneously.

FIG. 9 is a perspective view illustrating a specific display state. The detection area VF corresponding to the observation visual field is in front of the driver UN who is the observer. It is considered that objects OB1 and OB3 of people such as pedestrians and objects OB2 of moving bodies such as automobiles exist in the detection area VF, that is, in the road and its surroundings. In this case, the main control device 90 causes the image display device 100 to project a three-dimensional display image (virtual image) IM, and frame frames HW1, HW2, HW3 as related information images for the respective objects OB1, OB2, OB3. Is added. At this time, since the distances from the driver UN to the respective objects OB1, OB2, OB3 are different, the virtual image distance from the driver UN to the respective object OB1, OB2, OB3 to the display images IM1, IM2, IM3 for displaying the frame frames HW1, HW2, HW3. It corresponds to the distance to OB1, OB2, and OB3.

The virtual image distances of the display images IM1, IM2, IM3 are discrete, and it is not possible to always exactly match the actual distances to the objects OB1, OB2, OB3. However, unless the difference between the virtual image distances of the display images IM1, IM2, IM3 and the actual distances to the objects OB1, OB2, OB3 is large, parallax hardly occurs even if the viewpoint of the driver UN moves, and the object OB1, The arrangement relationship between the OB2, OB3 and the frame frames HW1, HW2, HW3 can be substantially maintained.

10A corresponds to FIG. 5, FIG. 10B corresponds to the display image IM3 or the frame frame HW3 in FIG. 9, FIG. 10C corresponds to the display image IM2 or the frame frame HW2 in FIG. 9, and FIG. Corresponds to the display image IM1 or frame frame HW1 in FIG. As is clear from FIGS. 10A to 10D, the display image IM1 is a projection image when the functional area FA of the rotating body 16a or the intermediate image TI is wholly or partially within a predetermined range centered on the display position PO1. Or, it corresponds to the displayed image. Similarly, the display image IM2 corresponds to a projection image or a display image when all or part of the functional area FA of the rotating body 16a or the intermediate image TI is in a position within a predetermined range with the display position PO2 as the center, The display image IM3 corresponds to the projection image or the display image when all or part of the functional area FA of the rotating body 16a or the intermediate image TI is in a position within a predetermined range around the display position PO3. When viewed in one cycle based on the movement of the intermediate image TI, the display image IM1 or the frame frame HW1 corresponding to the display position PO1 is sequentially displayed, and the display image IM2 or the frame frame HW2 corresponding to the display position PO2 is displayed in order. , The display image IM3 or the frame HW3 corresponding to the display position PO3 is displayed. If the above 1 cycle is visually short, the switching of the display images IM1, IM2, IM3 becomes very fast, and the driver UN who is the observer simultaneously observes the frame frames HW1, HW2, HW3 as a deep image. Recognize that you are doing.

According to the image display device 100 described above, a color image is displayed by synchronously controlling the operation of the intermediate screen 19 and the operation of the drawing device 11 based on the position of the intermediate screen 19 and the light emission timing of the drawing device 11. It is possible to stabilize the operation of the image display device 100 for drawing.

[Second Embodiment]
The display device according to the second embodiment will be described below. The display device of the second embodiment is a modification of the display device of the first embodiment, and matters not particularly described are the same as those of the first embodiment.

In the present embodiment, the display control unit 18 feeds back the light emission timing of the drawing device 11 and the position information of the intermediate screen 19 to control the drawing device 11 at a constant light emission timing, and is a rotation drive unit 64 that is an arrangement changing device. Of the intermediate screen 19 with respect to the operation of the drawing device 11. Accordingly, the operation of the intermediate screen 19 can be controlled while keeping the operation of the drawing device 11 constant.

Hereinafter, a method of synchronizing the operation of the intermediate screen 19 and the operation of the drawing device 11 of this embodiment will be described. First, as shown in FIG. 11, under the control of the display control unit 18, the rotating body 16a is operated at a predetermined rotation speed by using the rotation driving unit 64, and the intermediate screen 19 is moved along the optical axis AX. Further, the drawing device 11 is operated at a predetermined light emission timing and light emission time under the control of the display control unit 18 (step S11).

Next, the position of the intermediate screen 19 is detected (step S12). A rotation signal accompanying the rotation of the rotating body 16a is obtained as a pulse signal of the position detection element 65.

Next, the light emission timing and light emission time of the drawing device 11 operated by the display control unit 18 are acquired (step S13).

Next, under the control of the display control unit 18, the PID control unit 81 and the servo mechanism 82 feed back the light emission timing of the drawing device 11 and the position information of the intermediate screen 19, and the rotation drive unit 64 controls the drawing device 11 to rotate. The movement timing of the intermediate screen 19 is adjusted with respect to the operation (step S114). At this time, the display control unit 18 operates the drawing device 11 at a predetermined light emission timing and light emission time. As a result, the frame rate including the R, G, and B images of the drawing device 11 is adjusted, and the color image corresponding to the position of the intermediate screen 19 is displayed as a virtual image.

The main controller 90 confirms whether or not the display is continued (step S15), and when the display is continued (Y in step S15), the process returns to step S11 and the processes of step S12 and the like are repeated.

[Third Embodiment]
The display device according to the third embodiment will be described below. The image display device of the third embodiment is a modification of the display devices of the first and second embodiments, and matters not particularly described are the same as those of the first embodiment and the like.

In the present embodiment, the display control unit 18 feeds back the light emission timing of the drawing device 11 and the position information of the intermediate screen 19 to control the light emission timing and the light emission time of the drawing device 11 while being a rotation drive unit that is a layout changing device. The drive timing of 64 is controlled, and the operation of the drawing device 11 and the operation of the intermediate screen 19 are mutually adjusted. Thereby, the operation of the drawing device 11 and the operation of the intermediate screen 19 can be adjusted more accurately.

Hereinafter, a method of synchronizing the operation of the intermediate screen 19 and the operation of the drawing device 11 of this embodiment will be described. First, as shown in FIG. 12, under the control of the display control unit 18, the rotating body 16a is operated at a predetermined rotation speed by using the rotation driving unit 64, and the intermediate screen 19 is moved along the optical axis AX. Further, the drawing device 11 is operated at a predetermined light emission timing and light emission time under the control of the display control unit 18 (step S11).

Next, under the control of the display controller 18, the light emission timing of the drawing device 11 and the position information of the intermediate screen 19 are fed back, and the drawing device 11 is operated at the predetermined light emission timing and light emission time fed back and rotated. The movement timing of the intermediate screen 19 is adjusted via the drive unit 64 (step S214). As a result, the frame rate including the R, G, and B images of the drawing device 11 is adjusted, and the color image corresponding to the position of the intermediate screen 19 is displayed as a virtual image.

The display device as a specific embodiment has been described above, but the display device according to the present invention is not limited to the above. For example, the projection optical system 15 and the magnifying projection optical system 17 shown in FIG. 2 and the like are merely examples, and the optical configurations of the projection optical system 15 and the magnifying projection optical system 17 can be appropriately changed.

In the above embodiment, the display device 6 that constitutes the drawing device 11 is not limited to the DMD, and devices based on various operating principles can be used. For example, a reflective element such as LCOS (Liquid crystal on silicon), a liquid crystal display (LCD), or another type of display device such as an organic EL may be used.

In the above-described embodiment, the intermediate screen 19 is not limited to the spiral screen, and may be a plate-like one that reciprocates in the optical axis direction, and has a plurality of regions having different thicknesses and the plurality of regions are sequentially arranged on the optical path. It may be replaced to change the optical path length. In this case, as the position detecting element 65, one that can detect the position of the intermediate screen 19 corresponding to the configuration of the intermediate screen 19 is used.

In the above embodiment, the arrangement of the image display device 100 may be turned upside down, and the display screen 20 may be placed above the front window 8 or at the sun visor position. In this case, the display screen 20 is arranged diagonally below and in front of the drawing unit 10. Although the display screen 20 is a flat surface or a concave surface in the above embodiment, it may be a free-form surface having no symmetry.

In the above embodiment, the contour of the display screen 20 is not limited to a rectangle, but can be various shapes.

Claims

Drawing device,
A projection optical system for magnifying an image formed on the drawing device,
An intermediate screen having a diffusing function and arranged on the light exit side of the projection optical system,
An enlarged projection optical system for converting the image on the intermediate screen into a virtual image,
An arrangement changing device for changing the position of the intermediate screen along the optical axis direction,
A position detecting element for detecting the position of the intermediate screen,
A display control unit that controls at least one of the operation of the intermediate screen and the operation of the drawing device, based on position information of the intermediate screen obtained from the position detection element and information regarding light emission timing of the drawing device,
Equipped with
The drawing device is a display device that draws R, G, and B images that form a color image at a timing when the intermediate screen is arranged at a predetermined position.
The display device according to claim 1, wherein the position detection element is provided at the intermediate screen or a detectable position of the intermediate screen.
The display device according to any one of claims 1 and 2, wherein the display control unit acquires position information of the intermediate screen from the position detection element in real time.
The display device according to any one of claims 1 to 3, wherein the display control unit acquires information regarding a light emission timing of the drawing device in real time.
The display control unit, based on the position information of the intermediate screen and the light emission timing of the drawing device, the arrangement changing device so that the movement timing of the intermediate screen and the light emission timing of the drawing device have a predetermined synchronization relationship. The display device according to claim 3, wherein at least one of the drawing device and the drawing device is controlled.
The display control unit feeds back the light emission timing of the drawing device and the position information of the intermediate screen, controls the light emission timing and the light emission time of the drawing device, and operates the drawing device with respect to the operation of the intermediate screen. The display device according to claim 5, wherein the display device is adjusted.
The display control unit feeds back the light emission timing of the drawing device and the position information of the intermediate screen, and controls the drive timing of the arrangement changing device while controlling the drawing device at a constant light emission timing. The display device according to claim 5, wherein the operation of the intermediate screen is adjusted with respect to the operation of.
The display control unit feeds back the light emission timing of the drawing device and the position information of the intermediate screen, controls the light emission timing and the light emission time of the drawing device, controls the drive timing of the arrangement changing device, and performs the drawing. The display device according to claim 5, wherein the operation of a device and the operation of the intermediate screen are mutually coordinated.