WO2019070079A1 - Display device and display method using same - Google Patents

Abstract

Provided is a display device whereby high-luminance images can be simultaneously projected to a plurality of distance positions. A head-up display device 200 as the display device is provided with an image-forming optical system 15 which is a first projection optical system for projecting display light DL as picture light formed by a drawing device 11 which is a display element, an intermediate screen 19 for diffusing light in a position of projection by the image-forming optical system 15, a virtual-image-forming optical system 17 which is a second projection optical system for enlarging and projecting an intermediate image TI formed on the intermediate screen 19, a rotary drive unit 64 for causing a function region of the intermediate screen 19 to move in an optical axis AX direction, and a main control unit 90 for causing display to be performed by the drawing device 11 in synchronization with the movement of the intermediate screen 19 for changing the projection distance, and performing a setting so that projection distances partially overlap in adjacent display zones DZ1-Zn among a plurality of display zones in which the projection distance is changed.

Description

Display device and display method using the same

The present invention relates to a display device in which the projection position of a virtual image is variable, and a display method thereof.

Some display devices generate display images as virtual images at a plurality of locations at different distances from the driver (Patent Documents 1 to 6).

For example, in the apparatus of Patent Document 1, in an optical system for forming a virtual image, two mirror surfaces having different curvatures are provided as reflection mirrors, and the projection distance of a virtual image is obtained by switching mirrors disposed on the light path by their rotation. It is variable.

Further, in the apparatus of Patent Document 2, in the optical system for virtual image formation, a virtual image is formed using a plurality of display panels different in arrangement, thereby changing the display distance to the virtual image without providing the movable portion.

In the apparatus of Patent Document 3, in the optical system for virtual image formation, a condensing lens which moves in the optical axis direction to change the magnification of the display image is used, and by using a beam expander for the condensing lens, a display image or There is a description that the position of the virtual image in the optical axis direction can be adjusted.

In the apparatus of Patent Document 4, a relay optical system is disposed between the display element and the imaging optical system, and while an intermediate image is formed by the relay optical system, the position of the optical element constituting the relay optical system is changed. The position of the intermediate image is changed, and the projection distance of the virtual image is changed.

In the device of Patent Document 5, the display screen of the head-up display (hereinafter also referred to as HUD) device is vertically divided and projected on the near side and the far side. At this time, regarding the display on the far side, the intermediate screen is moved to make the projection distance of the virtual image variable.

In the apparatus of Patent Document 6, a laser scanning is used in an optical system for forming a virtual image, an intermediate screen is disposed in an optical path, and a projection distance of a virtual image is made variable by moving the intermediate screen.

However, the apparatus of Patent Document 1 obtains two projection distances using two mirror surfaces, and if it is attempted to increase the number of set projection distances, the number of mirrors is increased, and the apparatus becomes larger and more complex. .

Further, in the device of Patent Document 2, since the position of each display panel and the display distance resulting therefrom are fixed, the projection distance can not be changed at any position in the screen.

In patent document 3, the meaning of changing the projection distance of a virtual image is not demonstrated, and the concrete method of position adjustment of a virtual image is not shown, either.

The device of Patent Document 4 moves the optical element of the relay optical system, but there is no description about the specific driving method of the optical element and the method of changing the display accompanied therewith, and high brightness images are obtained at a plurality of distance positions. There is no disclosure about the method of projecting simultaneously.

In the devices of Patent Documents 5 and 6, the intermediate screen is moved, but the method of driving the intermediate screen and the method of changing the display associated therewith are not described, and a method of simultaneously projecting high-brightness images at a plurality of distance positions There is no disclosure of

Japanese Patent Application Laid-Open No. 9-185012 JP 2004-168230 A Unexamined-Japanese-Patent No. 2007-94394 JP 2008-180759 A JP, 2015-11211, A JP, 2009-150947, A

The present invention has been made in view of the above background art, and provides a display device such as a head-up display device capable of simultaneously projecting high brightness images at a plurality of distance positions, and a display method using the same. To aim.

In order to achieve at least one of the above-described objects, a display device reflecting one aspect of the present invention includes a first projection optical system that projects image light formed by a display element, and a first projection optical system. The intermediate screen that diffuses light at the projection position, the second projection optical system that magnifies and projects the intermediate image formed on the intermediate screen, the drive unit that moves the functional area of the intermediate screen in the optical axis direction, and the projection distance change And a control unit configured to cause the display element to perform display in synchronization with the movement of the intermediate screen to be displayed, and to set the projection distances to partially overlap in adjacent display zones among a plurality of display zones for changing the projection distance. Prepare.

In order to realize at least one of the above-mentioned objects, a display method reflecting one aspect of the present invention is a display method by a display device which magnifies and projects image light formed by a display element through an intermediate screen. And causes the display element to display in synchronization with the movement of the intermediate screen changing the projection distance by the movement in the optical axis direction, and the projection distance is partial in the adjacent display zones among the plurality of display zones changing the projection distance. Set to overlap.

FIG. 1A is a side cross-sectional view showing a state in which a head-up display device, which is the 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 explaining the head-up display device. is there. It is an expansion side sectional view explaining a concrete example of composition of a projection optical system etc. which constitute a head up display device which is a display. FIGS. 3A and 3B are a partially broken plan view and a partially broken side view for explaining the structure of the diffusion unit incorporating the intermediate screen, and FIG. 3C is a perspective view for explaining the rotating body in the diffusion unit. FIGS. 4A and 4B are side views for explaining the setting of the reference axis of the rotating body, and FIG. 4C is a view for explaining the movement of the functional area accompanying the rotation of the intermediate screen. It is a figure which illustrates change of a position of an intermediate image concretely. It is a figure which shows the relationship between the position of an intermediate image, and a projection distance, and demonstrates a display zone and a distance zone. It is a block diagram explaining the whole structure of a head-up display apparatus. It is a perspective view explaining a concrete display state. FIG. 9A corresponds to FIG. 5, and FIGS. 9B to 9D correspond to the projected image or frame in FIG. It is a figure explaining the operation example of the head-up display apparatus shown in FIG. It is a conceptual diagram explaining an example of switching of the display in a display zone. It is a figure explaining the display apparatus or head-up display apparatus of 2nd Embodiment. It is a figure which illustrates concretely the change of the position of the intermediate image in a 2nd embodiment.

First Embodiment
Hereinafter, a head-up display device as a display device according to a first embodiment of the present invention and a display method thereof will be described with reference to the drawings.

FIGS. 1A and 1B are conceptual side cross-sectional views and a front view illustrating an image display device 100 in a head-up display device as a display device of the embodiment. The image display apparatus 100 is mounted, for example, in a vehicle body 2 of a car, and includes a projection unit 10 and a display screen 20. The image display device 100 displays a virtual image of image information displayed on a drawing device 11 (described later) in the projection unit 10 toward the driver VD via the display screen 20, and may also be called a display device.

The projection unit 10 of the image display apparatus 100 is installed in the dashboard 4 of the vehicle body 2 and embedded behind the display 50, and is display light which is image light corresponding to an image including driving related information and the like. Eject DL toward display screen 20. The display screen 20 is also called a combiner and is a semitransparent concave mirror or a plane mirror. The display screen 20 is erected on the dashboard 4 by the support of the lower end, and reflects the display light (image light) DL from the projection 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 DL reflected by the display screen 20 is led to an eye box (not shown) corresponding to the pupil PU of the driver VD seated on the driver's seat 6 and the peripheral position thereof. The driver VD can observe the display light DL reflected by the display screen 20, that is, the projected image IM as a virtual image in front of the vehicle body 2. On the other hand, the driver VD can observe external light transmitted through the display screen 20, that is, a front view, a real image of a car or the like. As a result, the driver VD superimposes an external image or a see-through image behind the display screen 20, and a projection image (virtual image including relevant information such as driving related information formed by the reflection of the display light DL on the display screen 20) ) IM can be observed.

Here, although the display screen 20 is configured separately from the front window 8, using the front window 8 as a display screen, the display area set in the front window 8 is projected, and the driver VD generates a projection image IM It may be configured to be able to observe the At this time, the reflection area can be secured by changing the reflectance of a partial area of the glass of the front window 8 by coating or the like. In addition, if the reflection angle at the front window 8 is, for example, about 60 degrees, the reflectance is secured to about 15%, and it can be used as a reflective surface having transparency even without providing a coat. Besides these, it is also possible to provide a display screen in a configuration which is sandwiched in the glass of the front window 8.

As shown in FIG. 2, the projection unit 10 includes a main optical system 13 which is a virtual image type magnifying imaging system including a drawing device 11, a display control unit 18 which operates the main optical system 13, a main optical system 13, and the like. And a housing 14 for housing the Among them, the combination of the main body optical system 13 and the display screen 20 constitutes a display optical system 30.

The body optical system 13 includes, in addition to the drawing device 11, an imaging optical system 15 which is a first projection optical system that forms an intermediate image TI obtained by enlarging the image formed on the drawing device 11, and the intermediate image TI as a virtual image. It includes a virtual image forming optical system 17 which is a second projection optical system to be converted, and a diffusion unit 16 disposed between the two optical systems 15 and 17 for projection.

The drawing device 11 is a display element having a two-dimensional display surface 11 a. An image formed on the display surface 11 a of the drawing device (display element) 11 is enlarged by the imaging optical system (first projection optical system) 15 and projected on the spiral intermediate screen 19 provided in the diffusion section 16. Ru. At this time, by using the drawing device 11 capable of two-dimensional display, switching of the projection image on the intermediate screen 19, that is, switching of the projection image IM displayed as a virtual image through the display screen 20 can be made relatively fast. The drawing device 11 may be a reflection type element such as DMD or LCOS, or may be a transmission type element such as liquid crystal. In particular, when DMD or LCOS is used as the drawing device 11, it is easy to switch images at high speed (including high-speed intermittent display) while maintaining the brightness, which is advantageous for display in which the virtual image distance or projection distance is changed. is there. When the display device 11 changes the display distance or the projection distance, the drawing device 11 operates at a frame rate of 30 fps or more, more preferably 60 fps or more with respect to each projection distance. This makes it possible to make a plurality of projection images (virtual images) IM appear to be simultaneously displayed to the driver VD at different projection distances. In particular, when switching the display at 90 fps or more, the DMD or LCOS is a candidate for the drawing device 11.

The diffusion unit 16 is disposed at a projection position or an imaging position (that is, an imaging planned position of an intermediate image or in the vicinity thereof) by the imaging optical system (first projection optical system) 15, and includes the rotating body 16a and the hollow frame 16b. And driven by a rotational drive unit (drive unit) 64 so as to rotate around the reference axis SX at a constant speed, for example.

FIG. 3A is a front view explaining the diffusion part 16, FIG. 3B is a side cross-sectional view explaining the diffusion part 16, and FIG. 3C is a perspective view explaining the rotating body 16a in the diffusion part 16. is there. The diffusion portion 16 has a spiral rotary body 16a having an outline close to a disc as a whole and a cylindrical hollow frame 16b accommodating the rotary body 16a.

The rotating body 16a has a central portion 16c and an outer peripheral optical portion 16p. One surface 16f formed on the outer peripheral optical portion 16p of the rotating body 16a is formed on a smooth surface or an optical surface, and an intermediate screen 19 is formed on the entire surface of the surface 16f. The surface 16 f of the rotating body 16 a functions as a three-dimensional shape portion 116. The intermediate screen 19 is a diffusion plate in which the light distribution angle is controlled to a desired angle. The intermediate screen 19 can be a sheet to be attached to the rotating body 16a, but may be a fine concavo-convex pattern formed on the surface of the rotating body 16a. Furthermore, the intermediate screen 19 may be formed so as to be embedded inside the rotating body 16a. The intermediate screen 19 forms an intermediate image TI by diffusing the incident display light DL (see FIG. 2). The other surface 16s formed on the outer peripheral optical portion 16p of the rotating body 16a is formed on a smooth surface or an optical surface. The rotating body 16 a is a light transmitting helical member, and the pair of surfaces 16 f and 16 s are helical surfaces having the reference axis SX as a helical axis. As a result, the intermediate screen 19 formed on the one surface 16f is also formed along the continuous spiral surface. The intermediate screen 19 is formed in a range corresponding to one cycle of the spiral. That is, the intermediate screen 19 is formed in the range of one pitch of the spiral. As a result, a stepped portion 16 j is formed at one position along the periphery of the diffusion portion 16, and this stepped portion 16 j has a difference in intermediate screen position in the optical axis AX direction or the reference axis SX direction at the position corresponding to the spiral end. It is something to give. That is, when the three-dimensional shape portion 116 includes the spiral shape portion, the functional area FA of the intermediate screen 19 described later can be moved in the optical axis AX direction by the rotation of the intermediate screen 19. As a result, it becomes easy to display while changing the projected images IM having different display positions including the depth direction at high speed. The step amount of the step portion 16 j is set by the specifications of the near side and the far side of the distance for projecting the virtual image, and the magnification of the virtual image forming optical system (second projection optical system) 17. At this time, if the step difference 16j is to give a distance difference or pitch of 30 mm or less, the thickness of the diffusion part 16 in the direction of the optical axis AX can be made relatively small, and the diffusion part 16 can be miniaturized. A design can be made in which the distance between the mirrors of the virtual image forming optical system (second projection optical system) 17 described later (the second projection optical system) 17 is narrowed, which is also effective in downsizing the apparatus. The stepped portion 16 j connects the steps between the spiral ends and has a connecting surface 16 k inclined with respect to a plane including the reference axis SX for rotating the diffusion portion 16. As described above, since the pair of surfaces 16f and 16s of the rotating body 16a is a helical surface having the reference axis SX as a helical axis, the rotating body 16a has a thickness t substantially equal to the reference axis SX or the optical axis AX direction. Have.

In the rotating body 16a, one portion along the circumferential direction is a functional area FA through which the optical axis AX of the main optical system 13 passes, and an intermediate image TI is formed by the portion of the intermediate screen 19 in the functional area FA. The functional area FA moves at a constant speed on the rotating body 16a as the rotating body 16a rotates. That is, the position of the functional area FA or the intermediate image TI reciprocates along the optical axis AX by causing the display light (image light) DL to be incident on the functional area FA which is a part thereof while rotating the rotating body 16 a. (If the display of the drawing device 11 is not working, the intermediate image as the display is not necessarily formed, but the position where the intermediate image will be formed is also called the position of the intermediate image). In the illustrated example, since the intermediate screen 19 is formed in a range corresponding to one cycle of the spiral, the functional area FA or the intermediate image TI of the intermediate screen 19 is stepped in the optical axis AX direction by one rotation of the rotating body 16a. It makes one round trip by a distance equivalent to The imaging optical system (first projection optical system) 15 has a predetermined focal depth greater than the movement range of the functional area FA so that defocusing does not occur depending on the position of the intermediate screen 19. Alternatively, by providing the above-described imaging optical system (first projection optical system) 15 with a focusing function, it is possible to obtain an image without blur.

The hollow frame 16b has a cylindrical outer contour, and includes a side surface portion 16e and a pair of end surface portions 16g and 16h. The side surface portion 16e and the pair of end surface portions 16g and 16h are formed of the same light transmitting material. However, the side surface portion 16 e may not have light transparency. The main surfaces 63a and 63b of one end surface portion 16g are smooth surfaces or optical surfaces parallel to each other, and the main surfaces 64a and 64b of the other end surface portion 16h are also smooth surfaces or optical surfaces parallel to each other There is. Here, the main surfaces 63a and 63b or the main surfaces 64a and 64b may not necessarily be parallel planes, and it is difficult to secure performance, for example, if the range corresponding to at least the functional area FA is a free curved surface or aspheric surface. Even in a high magnification optical system, it is possible to secure image performance such as distortion and image surface property required of the optical system, and therefore, it is sufficient to select a desired surface shape as needed. The rotating body 16a in the hollow frame 16b is fixed to the hollow frame 16b via the pair of central shaft portions 65, and the hollow frame 16b and the rotating body 16a integrally rotate around the reference axis SX Do. As described above, by arranging the rotary body 16a provided with the intermediate screen 19 in the hollow frame 16b, adhesion of dust and the like to the rotary body 16a can be suppressed, and the generation of sound accompanying the rotation of the rotary body 16a is realized. It can be suppressed and it becomes easy to stabilize the rotation at high speed of the rotating body 16a. The rotating body 16a may be fixed to the hollow frame 16b at its outer peripheral portion. In this case, it is easy to reduce the thickness t of the rotating body 16a.

The setting of the reference axis SX of the rotating body 16a (or the three-dimensionally shaped portion 116) will be described with reference to FIGS. 4A and 4B. The reference axis SX of the rotating body 16 a is disposed slightly incliningly in a non-parallel state with respect to the optical axis AX of the main body optical system 13. Here, the intermediate screen 19 on the rotating body 16 a is disposed so that the local functional area FA is substantially orthogonal to the direction of the optical axis AX of the main optical system 13. That is, as shown in FIG. 4A, when the rotating body 16a is observed from the optical axis AX at a lateral point away from the optical axis AX, the reference axis SX is inclined by the predetermined angle α with respect to the optical axis AX As shown in FIG. 4B, when observed from a viewpoint remote from the rotating body 16a in the direction orthogonal to the case of FIG. 4A, the reference axis SX has a predetermined distance d with respect to the optical axis AX. It is in the state of only being separated. In FIG. 4A, a first position PO1 indicated by an alternate long and short dash line indicates a case where the functional area FA or the intermediate image TI is located on the most upstream side of the optical path, and a second position PO2 indicated by an alternate long and short dash line It shows the case where the intermediate image TI is located on the most downstream side of the light path. The distance D between the positions PO1 and PO2 corresponds to the displacement of the functional area FA or the intermediate image TI in the optical axis AX direction.

Returning to FIG. 2, the intermediate screen 19 (or the three-dimensionally shaped portion 116) of the rotating body 16 a intersects the optical axis AX by rotating the diffusion unit 16 at a constant speed around the reference axis SX by the rotational drive unit 64. The position (that is, the functional area FA) also moves in the direction of the optical axis AX. That is, as shown in FIG. 4C, the functional area FA on the intermediate screen 19 is sequentially shifted, for example, to the adjacent functional areas FA 'set at positions offset at equal angles, as the rotating body 16a rotates. 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. Although the details will be described later, for example, by moving the position of the intermediate image TI to the virtual image forming optical system 17 side, it is possible to reduce the projection distance or virtual image distance to the projection image IM. In addition, by moving the position of the intermediate image TI to the drawing device (display element) 11 side, it is possible to increase the projection distance or virtual image distance to the projection image IM.

The virtual image forming optical system (second projection optical system) 17 enlarges the intermediate image TI formed by the imaging optical system (first projection optical system) 15 in cooperation with the display screen 20, and in front of the driver VD A projected image IM as a virtual image is formed. The virtual image forming optical system 17 includes at least one mirror, but includes two mirrors 17 a and 17 b in the illustrated example. The virtual image forming optical system (second projection optical system) 17 can have optical characteristics to correct the curvature of the intermediate screen 19 (that is, the curvature of field of the intermediate image TI) in the functional area FA of the rotary member 16a.

In the image display apparatus 100 shown in FIG. 2 and the like, by operating the rotary drive unit 64 under the control of the display control unit 18, the diffusion unit 16 rotates around the reference axis SX and the position of the intermediate image TI is the optical axis. The distance between the projected image IM as a virtual image formed behind the display screen 20 by the virtual image forming optical system 17 and the driver VD which is an observer can be increased or decreased by periodically moving repeatedly in the AX direction. . As described above, the position of the projected image IM to be projected is changed back and forth, and the display content by the drawing device (display element) 11 is made to correspond to the position under the control of the display control unit 18 The display content of the projected image IM is changed while changing the projection distance or virtual image distance to the image IM, and the projected image IM as a series of projected images can be made three-dimensional. Since the curved state of the intermediate screen 19 in the functional area FA is maintained even if the functional area FA moves in the direction of the optical axis AX, the virtual image forming optical system (second projection optical system regardless of the position of the projected image IM The effect of the correction by 17) is maintained.

The rotational speed of the diffusion unit 16 or the rotating body 16a or the moving speed of the functional area FA is a speed that can make it appear as if a projected image IM as a virtual image is simultaneously displayed at a plurality of points or a plurality of projection distances. desirable. Here, if the projected image IM of each distance zone (sub-zone described later) is switched at 30 fps or more, preferably 60 fps or more, a plurality of displayed images are recognized as continuous images. For example, assuming that the projection image IM is sequentially projected in five steps from the short distance to the long distance according to the operation of the diffusion unit 16, each distance (for example, the short distance) In the projected image IM, display switching is performed at 40 fps, and the projected images IM of each distance are performed in parallel, and the switching is recognized as substantially continuous.

FIG. 5 is a diagram specifically illustrating the change in the position of the intermediate image TI as the diffusion unit 16 rotates. The functional area FA of the diffusion unit 16 is repeatedly and periodically moved along the optical axis AX in a saw-tooth-shaped time-lapse pattern PA, and the drawing device (display element) 11 continuously displays the position of the intermediate image TI. In the case where it is carried out, as shown in the drawing, it moves periodically in a sawtooth-like time-lapse pattern PA along the direction of the optical axis AX. That is, the position of the intermediate image TI changes continuously and periodically along with the rotation of the diffusion portion 16 while being discontinuous at the portion corresponding to the step portion 16 j. As a result, although not shown, the position of the projected image (virtual image) IM is also periodically moved along the optical axis AX direction similarly to the position of the intermediate image TI although the scale is different, and the projection distance is continued Can be changed. Here, since the drawing device 11 does not perform continuous display but performs intermittent display while switching the display content, the display position of the intermediate image TI is also a discrete position on the sawtooth-like temporal pattern. It becomes. In the temporal pattern PA, the display position Pn closest to the near side and the display position Pf distant to the far side are set at positions distant from both ends of the temporal pattern PA with a margin secured. Further, the discontinuity PD of the temporal pattern PA corresponds to the step portion 16 j provided on the rotating body 16 a of the diffusion portion 16. Here, in the example shown in FIG. 5, the position of the intermediate image TI is changed in a sawtooth shape with a constant inclination with respect to time, but the rotation of the diffusion unit 16 is also taken into consideration with respect to the specification of the distance to be displayed. It is desirable to change the position so that the display timing can be controlled, and depending on the specification of the display distance, the change may not be a constant inclination.

Here, when displaying an image of a certain distance zone, the displayed distance changes because the position of the intermediate image TI changes within the displayed time as shown in FIG. At this time, the display distance seen by the observer (driver VD) for the display zone in which the distance changes in such a manner is a substantially average position of the distance changing within the display time.

FIG. 6 is a diagram for explaining the relationship between the position of the intermediate image TI and the projection distance or the relationship between the position of the intermediate image TI and the display zone. When the intermediate image TI is moved at the same speed in the direction of the optical axis AX according to the characteristic C1 indicated by the one-dot chain line, the step width of the projection distance is short at a short distance if the step δ of switching time of each distance zone is a constant value. Short, long at long distances. The step size Δ of the movement of the intermediate image TI corresponds to the switching time of the distance zone to be displayed.

Assuming that the time taken to move between the position ends of the intermediate image TI shown in FIG. 5 is one cycle, the unit of display having depth is a display zone, and the time of one cycle is the display time of each display zone and the display zone If the time is shorter than the product of several n, the display zones extend over a plurality of distance zones, and at least adjacent display zones overlap in the projection distance range (see display zones DZ1 to DZn in FIG. 6). By performing overlapping display in this manner, the same projected image (virtual image) IM can be displayed with a spread in the depth direction, and the display time of each display zone can be displayed as compared to the display in which no overlap occurs. This makes it possible to increase the brightness of the projected image (virtual image) IM.

As shown in FIG. 6, n display zones can be set along the characteristic C1. Here, for convenience of explanation, the display zone with the closest distance is called the first display zone DZ1, and the display zone with the longest distance is called the n-th display zone DZn (n is a natural number). In the plurality of display zones DZ1 to DZn, the distance width to be displayed increases as the distance from the near distance increases. In this case, it means that the depth of the display object or the composite projected image IM spreads on the far side, but since the parallax is smaller as the distance is smaller, there is almost no influence on the display state. Of the plurality of display zones DZ1 to DZn, adjacent display zones overlap in projection distance partially, and each display zone includes one in which the projection distances should be originally made different. That is, the projection distances of the k-th display zone DZk (k is a natural number smaller than n) and the (k + 1) -th display zone DZk + 1 partially overlap, for example, the second display zone DZ2 and the third display zone DZ3 are projection distances Are partially overlapping. The k-th display zone DZk also displays an image to be displayed in a display zone set before, after, or both before and after the original display image of the projection distance of the display object to be displayed there It is a complex projection image. The display zone includes subzones in which the distance to be projected gradually changes. In the illustrated example, the display of the state in which the images corresponding to the distance zones or subzones LZk-2 to LZk + 1 corresponding to four sections over the entire or a predetermined time while displaying the k-th display zone DZk is overlapped It is done. In this case, the display time of the image displayed in each of the display zones DZ1 to DZn is shifted between the adjacent display zones DZ1 to DZn at the pitch δ of the display time. The distance between the near and far ends fluctuates and the average distance also fluctuates. The human eye or brain captures the display image by the average distance of the display zones DZ1 to DZn, and therefore, even when visual display is simultaneously performed, the display distances of the respective display zones DZ1 to DZn are displayed as different positions. Can be in the

When the k-th display zone DZk is divided as the overlapping distance zone switches and is considered as a series of subzones LZk-2 to LZk + 1 having different projection distances including the reference subzone LZk, the drawing device (display element) 11 is appropriately selected. By performing the display operation, the same projected image (virtual image) IM is displayed in each sub zone. That is, the display zone DZk is configured by a combination of a plurality of sub-zones LZk-2 to LZk + 1 in which the distance changes stepwise. From a different point of view, local images to be projected in the distance zone corresponding to one reference sub-zone LZk to be focused are displayed repeatedly, for example, in four display zones in an overlapping manner. The image has a uniform luminance. At this time, the position and the angle of a common local projected image (virtual image) IM projected onto a distance zone (corresponding to subzones LZk-2 to LZk + 1) common to adjacent display zones in consideration of a change in projection distance. Overlap and display so that the size matches. As a result, it is possible to display the projected image (virtual image) IM, in which the projection distance changes, in a state without displacement or blurring. Further, the display distance at this time is a distance corresponding to the reference sub-zone LZk. Although each display zone DZ1 to DZn is shown to extend in the horizontal direction for convenience of display in FIG. 6, each display zone DZ1 to DZn has a characteristic when the vertical axis is the position of the intermediate image TI. It extends along C1.

The display times in the first display zone DZ1 to the nth display zone DZn are all equal. By equalizing the display time in each of the display zones DZ1 to DZn constituting a plurality of display zones, it is possible to make the display luminance of the composite projected image IM by each of the display zones DZ1 to DZn coincide with each other. It is possible to prevent the driver VD from unintentionally focusing on an image of a specific distance. Depending on the application, it is possible to make a difference in display luminance in each of the display zones DZ1 to DZn. For example, for the display zone corresponding to the far-distance projection, processing such as increasing the display brightness is possible.

Although the first to third pre-interpolation zones CZ1 to CZ3 added to the projection at the near end are added in view of setting the display distance in the first distance zone LZ1 to a desired distance, it is not essential. . Similarly, although the first to third post-interpolation zones CZ4 to CZ6 added to the projection of the far end are added in view of setting the display distance in the nth distance zone LZn as a desired distance, it is essential It is not a thing.

When displaying different objects in a specific depth direction in the screen, display objects with different distances are in close positions such as overlapping or substantially overlapping in a two-dimensional plane other than the depth direction, and interference between the displays with respect to them is It is thought that it may occur and it is necessary to avoid this. For example, when a display target existing at another display distance DZk 'with respect to the display target in the display zone DZk is located in the vicinity in a two-dimensional plane and interference occurs in display for each target, those in the interference area It is conceivable to make a display that synthesizes Specifically, in a common area or intersection area in which a pair of display targets overlap, an image is displayed such that the pair of display targets is displayed in semi-transparent superposition, and in a difference area or an independent area in which the pair display targets do not overlap, each portion It is sufficient to use a standard display. Alternatively, a method may be considered in which display is made with differences in methods such as color and size (including thickness in the case of a line), brightness, and blinking, and it may be devised to be transmitted to the driver VD.

FIG. 7 is a conceptual block diagram for explaining the overall structure of the head-up display device 200. The head-up display device 200 includes the image display device 100 as a part thereof. The image display apparatus 100 has a structure shown in FIG. 2, and the description thereof is omitted here.

The head-up display device 200 includes an environment monitoring unit 72 and a main control unit 90 in addition to the image display device 100.

The environment monitoring unit 72 is an object detection unit that detects an object present in the detection area, and identifies a mobile object or person existing close to the front, specifically a car, a bicycle, a pedestrian, etc., as an object. And a three-dimensional measuring device for extracting three-dimensional position information of the object. The environment monitoring unit (object detection unit) 72 includes an external camera 72a, an external image processing unit 72b, and a determination unit 72c as a three-dimensional measuring device. The external camera 72a enables capturing of an external image in the visible or infrared region. The external camera 72a is installed at an appropriate position inside and outside the vehicle body 2, and captures a driver VD or a detection area VF in front of the front window 8 (see FIG. 8 described later) as an external image. The external image processing unit 72b performs various image processing such as brightness correction on the external image captured by the external camera 72a to facilitate the processing in the determination unit 72c. The determination unit 72c performs extraction or clipping of an object image from an external image that has passed through the external image processing unit 72b to extract an object such as a car, a bicycle, or a pedestrian (specifically, an object OB1, OB1 in FIG. The presence or absence of OB2 and OB3 is detected, and the spatial position of the object in front of the vehicle body 2 is calculated from depth information attached to the external image and stored in the storage unit 72m as three-dimensional position information. Software that enables extraction of an object image from an external image is stored in the storage unit 72m of the determination unit 72c, and software and the like required from the storage unit 72m at the time of an operation of extracting an object image from an external image. Data is read out. The determination unit 72c can detect, for example, an element corresponding to an object element from the shape, size, color and the like of each object element in the obtained image. The determination criteria at that time include a method of performing pattern matching with information registered in advance and detecting something from the degree of matching. Further, from the viewpoint of increasing the processing speed, the lane can be detected from the image, and the object can be detected from the shape, size, color, etc. of the target or the object element in the lane.

The external camera 72a is, for example, a compound eye type three-dimensional camera, although illustration is omitted. That is, the external camera 72a is an array of camera elements in which a lens for image formation and an imaging element such as a CMOS are arranged in a matrix, and each has a driving circuit for the imaging element. A plurality of camera elements constituting the external camera 72a can detect, for example, relative parallax, and by analyzing the state (focus state, position of an object, etc.) of an image obtained from the camera elements, A target distance to each region or object in the image corresponding to the detection region can be determined.

Note that even if 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, the depth direction of each part (area or object) in the photographed screen is obtained. A target distance which is distance information can be obtained. In addition, instead of the compound-eye type external camera 72a, obtain a target distance which is distance information in the depth direction with respect to each part (area or object) in the photographed screen by a stereo camera in which two two-dimensional cameras are separately arranged. Can. In addition, by performing imaging while changing the focal length at a high speed with a single two-dimensional camera, it is also possible to obtain a target distance which is distance information in the depth direction with respect to each part (area or object) in the photographed screen. it can.

Further, distance information in the depth direction can be obtained for each part (area or object) in the detection area even if the LIDAR technology is used instead of the compound eye type external camera 72a. With LIDAR technology, it is possible to measure scattered light for pulsed laser irradiation and measure the distance and spread to a distant object to obtain information on the distance and spread of an object within the field of view. . Furthermore, the object detection accuracy can be enhanced by a complex method that combines radar sensing technology such as LIDAR technology and technology that detects the distance of an object from image information, that is, a method that fuses multiple sensors. Can.

The operating speed of the external camera 72a for detecting an object needs to be equal to or higher than the operating speed of the drawing device (display element) 11 from the viewpoint of speeding up input, and the display switching speed or display zone of the display zones DZ1 to DZn. When the display period of one cycle of DZ1 to DZn is, for example, 30 fps or more, it is desirable to make this faster. It is desirable that the external camera 72a enables high-speed detection of an object by, for example, high-speed operation such as 480 fps or 1000 fps, which is faster than 120 fps. Moreover, when fusing a plurality of sensors, all the sensors do not necessarily have to be fast, and at least one sensor of the plurality of sensors needs to be fast, but the others may not be fast. In this case, it is possible to use a method of enhancing sensing accuracy by using data that is detected by a high-speed sensor as a basis and complementing with data of a non-high-speed sensor.

The display control unit 18 operates the display optical system 30 under the control of the main control unit 90 to display a three-dimensional projected image IM in which the virtual image distance or the projection distance changes behind the display screen 20.

The main control unit 90 has a role of harmonizing the operations of the image display apparatus 100, the environment monitoring unit 72, and the like. The main control unit 90 operates the rotation drive unit 64 via, for example, the display control unit 18 to periodically change the projection distance of the virtual image which is the projection image IM by the display optical system 30. That is, the main control unit 90 or the like periodically changes the projection position in the depth direction of the virtual image which is the projection image IM. Further, the main control unit 90 adjusts the spatial arrangement of the frame HW (see FIG. 8) projected by the display optical system 30 so as to correspond to the spatial position of the object detected by the environment monitoring unit 72. Do. That is, the main control unit 90 generates a projection image IM to be displayed on the display optical system 30 from the display information including the display shape and the display distance received from the environment monitoring unit 72. The display content of the projected image IM is synchronized with the operation of the rotation drive unit 64, that is, synchronized with the movement of the intermediate image TI. The projected image IM may be, for example, a sign such as a frame HW (see FIG. 8) positioned around a vehicle, bicycle, pedestrian or other object present behind the display screen 20 with respect to its depth position direction. Can. Although this frame HW is shown without depth for the convenience of explanation, in actuality, it has a fixed depth width corresponding to the depth width of the display zones DZ1 to DZn. As described above, the main control unit 90 functions as an image adding unit in cooperation with the display control unit 18 and detects an object detected at a timing when the target distance to the detected object substantially matches the projection distance. On the other hand, the related information image is added as a virtual image by the display optical system 30.

The main control unit 90 assigns a single display target to at least a single display zone and causes the drawing device (display element) 11 to display. In this case, although a single display target is displayed in a single display zone including a specific projection distance in principle, a single display target may be displayed in a plurality of display zones.

The main control unit 90 sets an image corresponding to a series of adjacent distance zones among a plurality of distance zones whose projection distances are changed by the movement of the intermediate screen 19 as a plurality of subzones constituting the display zones DZ1 to DZn. The same projection image IM is repeatedly displayed as a plurality of subzones corresponding to the distance zone. In this case, the distance zone corresponds to the minimum unit of distance resolution, and the distance range is expanded by repeatedly displaying the same projected image IM in distance zones having different projection distances, but the display of the projected image IM is performed. It will increase the brightness.

FIG. 8 is a perspective view for explaining a specific display state. The front of the driver VD which is an observer is a detection area VF corresponding to the observation field of view. It is considered that objects OB1 and OB3 of people who are pedestrians or the like and objects OB2 of moving objects such as automobiles exist in the detection area VF, that is, on the road and its surroundings. In this case, the main control unit 90 causes the image display device 100 to project a three-dimensional projected image (virtual image) IM, and frame frames HW1, HW2, HW3 as related information images for the respective objects OB1, OB2, OB3. Add At this time, since the distances from the driver VD to the objects OB1, OB2, and OB3 are different, the projection distances to the projected images IM1, IM2, and IM3 for displaying the frame frames HW1, HW2, and HW3 It corresponds to the distance to OB2 and OB3.

The projection distances of the projected images IM1, IM2, IM3 are formed in the display zones DZa-DZc corresponding to a part of the display zones DZ1-DZn shown in FIG. 6, and the depths corresponding to the respective display zones DZa-DZc. It has a width. The centers of the projection distances, that is, the projection distances of the projection images IM1, IM2, and IM3 are discrete, and can not always be exactly matched with the real distances to the objects OB1, OB2, and OB3. However, if the difference between the projection distances of the projected images IM1, IM2, IM3 and the actual distances to the objects OB1, OB2, OB3 is not large, parallax does not easily occur even if the viewpoint of the driver VD moves, and the objects OB1, OB2 , OB3 and the frame frames HW1, HW2, HW3 can be substantially maintained.

9A corresponds to FIG. 5, FIG. 9B corresponds to the projected image IM3 or the frame HW3 in FIG. 8, FIG. 9C corresponds to the projected image IM2 or the frame HW2 in FIG. Corresponds to the projected image IM1 or the frame HW1 in FIG. As apparent from FIGS. 9A to 9D, the projected image IM1 is specifically determined when the functional area FA or the intermediate image TI of the rotating body 16a (or the solid shape portion 116) is within a predetermined distance range centered on the display position P1. Specifically, a series of lines formed on the display surface 11a of the drawing device (display element) 11 at the display timing of the predetermined display zone determined based on the characteristic C1 shown in FIG. 6 according to the distance range. Corresponds to the displayed image of. Similarly, the projected image IM2 is a series of displays formed on the display surface 11a of the drawing device 11 when the functional area FA of the rotary body 16a (or the three-dimensionally shaped portion 116) is within the distance range centered on the display position P2. Corresponding to the image, the projected image IM3 is formed on the display surface 11a of the drawing device 11 when the functional area FA of the rotary body 16a (or the solid shape portion 116) is within a predetermined distance range centered on the display position P3. Correspond to a series of displayed images. When viewed in one cycle based on the movement of the intermediate image TI, first, the projected image IM1 or the frame HW1 corresponding to the display position P1 is displayed, and then the projected image IM2 or the frame HW2 corresponding to the display position P2 is displayed Thereafter, the projected image IM3 or the frame HW3 corresponding to the display position P3 is displayed. If the above one cycle is visually short, switching of the projected images IM1, IM2, IM3 becomes very fast, and the driver VD who is an observer simultaneously observes the frame HW1, HW2, HW3 as an image with depth. Recognize that In the present embodiment, for example, when at least any two of the display positions P1 to P3 are designated as adjacent display zones or close display zones, for example, the projected images in FIGS. 9B and 9C, FIGS. 9C and 9C. There is a time zone in which the projected images of FIG. 9D or all of the projected images of FIGS. 9B, 9C, and 9D are simultaneously displayed overlapping in the overlapping time range within the display time.

FIG. 10 is a conceptual diagram for explaining the operation of the main control unit 90. As shown in FIG. First, when the main control unit 90 detects the objects OB1, OB2, and OB3 using the environment monitoring unit 72, the main control unit 90 generates display data corresponding to the frame frames HW1, HW2, and HW3 corresponding to the objects OB1, OB2, and OB3. And store them in a storage unit (not shown) (step S11). Thereafter, the main control unit 90 converts data so as to distribute the display data obtained in step S11 to the corresponding display zones DZ1 to DZn (step S12). Specifically, in accordance with the positions of the objects OB1, OB2, and OB3, the corresponding frame frames HW1, HW2, and HW3 are set to any one of the display zones DZ1 to DZn (in the example of FIG. 8, the display zones DZa to DZc). assign. Next, the main control unit 90 processes the display data corresponding to the frame frames HW1, HW2, HW3 so as to conform to the allocated display zones DZ1 to DZn, and stores the display data in a storage unit (not shown) (step S13). This adaptation includes image processing such as correcting the outline and arrangement of the frame image for each of the distance zones or sub zones LZk-2 to LZk + 1. Thereafter, the main control unit 90 combines the display data adapted at step S13 with the existing data (step S14). The display by the display zones DZ1 to DZn is simultaneously performed in parallel although there is a time difference, and the display is such that an afterimage is left for a short time, so when new objects OB1, OB2, OB3 appear, the existing It is considered that the display content needs to be reorganized so that the new object and the object of. Finally, the main control unit 90 outputs the display data obtained in step S14 to the display control unit 18 in synchronization with the operation of the rotation drive unit 64, and the drawing device (display element) 11 functions as a functional area of the rotating body 16a. The display operation according to FA is performed (step S15).

FIG. 11 is a diagram for explaining the operation of the drawing device (display element) 11. In this case, the first display area to the nth display area arranged in the vertical direction correspond to the first to nth display zones DZ1 to DZn shown in FIG. In one cycle corresponding to one rotation of the rotating body 16a (or the solid shape portion 116), the first to nth display zones DZ1 to DZn in the display surface 11a of the drawing device (display element) 11 The display in the display area to the n-th display area is repeated. In each display area, signals F1 to F4 mean that the same display image is repeated in four sub zones, and R, G, and B signal components for color display are included in each of signals F1 to F4. ing.

According to the head-up display device 200 or the image display device 100 of the first embodiment described above, the drawing device (the main control unit 90 and the display control unit 18 synchronize with the movement of the intermediate screen 19 to change the projection distance) Since the display is performed on the display element 11, virtual images different in display position including the depth direction can be displayed at high speed while various images can be simultaneously projected on a plurality of distance positions. At this time, since the main control unit 90 and the display control unit 18 set the projection distances to partially overlap in the adjacent display zones DZk and DZk + 1 among the plurality of display zones DZ1 to DZn for changing the projection distances, for example, We considered displaying using the display zones DZ1 to DZn of the number of distance divisions set in one cycle, changing the display distance from the near end to the far end or from the far end to the near end In this case, the projection time or the display time by each display zone DZ1 to DZn can be extended by providing the overlap even with the same division number, as compared with the display in which the projection distances do not overlap in adjacent display zones DZk and DZk + 1. It becomes easy to project high brightness images simultaneously.

Second Embodiment
The display device and the like according to the second embodiment will be described below. The display device and the like according to the second embodiment is a modification of the display device and the like according to the first embodiment, and items that are not particularly described are the same as in the first embodiment.

As shown in FIG. 12, at the projection position or the imaging position of the imaging optical system 15, an intermediate screen 19 which is an optical element which moves in the direction of the optical axis AX is disposed. The intermediate screen 19 is a diffusion plate in which the light distribution angle is controlled to a desired angle, and for example, a ground glass, a lens diffusion plate, a microlens array or the like is used. In this case, the effective area of the intermediate screen 19 is the functional area of the intermediate screen 19.

The main control unit 90 as the control unit and the display control unit 18 periodically shift the position of the intermediate screen 19 via the reciprocating drive unit 264 to periodically shift the position of the intermediate image TI as shown in FIG. It is assumed that the image formed on the drawing device 11 corresponds to the projection distance while the reciprocating movement is performed to change the projection distance periodically. Specifically, the projection distance is periodically changed by reciprocating the intermediate screen 19 in the direction of the optical axis AX by the guide part 264a and the actuator 264b which constitute the reciprocating drive part 264.

When the position of the intermediate image TI is to be a time-lapse pattern PA of a triangular waveform shown in FIG. 13 or when it is reciprocated periodically in a sine curve, for example, the display zones DZ1 to Zn shown in FIG. After changing so as to sequentially switch from long distance to long distance, changing the display zones DZ1 to Zn to sequentially change distance from long distance to short distance is one cycle, and the same cycle is repeated.

[Others]
Although the head-up display device 200 as a specific embodiment has been described above, the display device according to the present invention is not limited to the above. For example, in the first embodiment, the display screen 20 can be arranged at the upper portion of the front window 8 or at the sun visor position by inverting the arrangement of the image display device 100 upside down. The display screen 20 is arranged at Also, the display screen 20 may be disposed at a position corresponding to a conventional mirror of a car.

In the above, the intermediate screen 19 or the functional area FA is disposed to be substantially orthogonal to the direction of the optical axis AX of the main body optical system 13. However, the functional area FA can be forcibly inclined with respect to the optical axis AX. . In this case, it is possible to project the projected image IM having no inclination or a predetermined inclination by the combination with the virtual image forming optical system 17.

The first to n-th display zones DZ1 to DZn described above do not need to be continuous over the entire range of projection distances, and are discontinuous at portions corresponding to the boundaries of subzones LZ1 to LZn It may be Further, the display zones DZ1 to DZn are not limited to those including the same number of subzones, and different subzones can be included for each of the display zones DZ1 to DZn.

In the first embodiment, one diffusion screen 16 is provided with one intermediate screen 19, but two or more intermediate screens 19 may be provided. In this case, the intermediate screen 19 is formed to be divided into ranges corresponding to 1/2 pitch, 1/3 pitch, etc. of the spiral.

The three-dimensional shape portion 116 of the intermediate screen 19 does not have to be a helical shape over the entire circumference, a shape in which a part of the entire circumference is a spiral, or a rotating body structure that enables reciprocation without steps. Is also conceivable.

In the diffusion portion 16, the hollow frame 16b is not essential, and can be only the rotating body 16a. Also in this case, since the inclined connection surface 16k is formed in the step portion 16j, the generation of the sound accompanying the rotation of the rotating body 16a can be suppressed, and the rotation of the rotating body 16a can be stabilized.

In the said embodiment, the outline of the display screen 20 can be made into various shapes not only in a rectangle.

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

In the above, the environment monitoring unit 72 detects the object OB existing in front of the vehicle body 2 and displays the related information image such as frame frames HW1, HW2, HW3 corresponding to the arrangement of the object OB on the image display device 100. Regardless of the presence or absence of the object OB, it is possible to obtain additional driving related information using the communication network, and to display such driving related information on the image display device 100. For example, a display that warns of a car, an obstacle, etc. present in a blind spot is also possible.

The display device of the present invention is not limited to a head-up display (HUD) device mounted on a vehicle or other mobile object, and can be applied to a head mount device that performs three-dimensional display, a wearable display device, and the like.

Claims (11)

A first projection optical system for projecting image light formed by the display element;
An intermediate screen for diffusing light at a projection position by the first projection optical system;
A second projection optical system that magnifies and projects the intermediate image formed on the intermediate screen;
A drive unit for moving the functional area of the intermediate screen in the optical axis direction;
The display is caused to be displayed on the display element in synchronization with the movement of the intermediate screen changing the projection distance, and the projection distances partially overlap in adjacent display zones among a plurality of display zones changing the projection distance A display device comprising a control unit to set. The display device according to claim 1, wherein the control unit makes the display time substantially the same for each of the display zones constituting the plurality of display zones. The display device according to any one of claims 1 and 2, wherein the control unit assigns a single display target to at least a single display zone and causes the display element to perform display. The display device according to any one of claims 1 to 3, wherein the display width of the plurality of display zones increases as the distance from the short distance to the distance increases. The control unit sets an image corresponding to a series of adjacent distance zones among a plurality of distance zones whose projection distances are changed by the movement of the intermediate screen, as a plurality of subzones constituting the display zone, in a specific distance zone. The display device according to any one of claims 1 to 4, wherein the same projection image is repeatedly displayed as the plurality of corresponding subzones. The head-up display device according to claim 5, wherein the same projection image is repeatedly displayed as a series of subzones having different projection distances including the reference subzone. The display device according to any one of claims 5 and 6, wherein the control unit superimposes and displays the same projection image so that the position and the angle size match in the distance zones having different projection distances. The intermediate screen has a three-dimensional shape that continuously changes the position in the optical axis direction of the functional area in the intermediate screen, and the drive unit rotates the intermediate screen about a reference axis. The display device according to any one of 7. The display device according to claim 8, wherein the three-dimensional shape portion includes a spiral shape portion. The display device according to any one of claims 1 to 7, wherein the drive unit periodically moves the intermediate screen in an optical axis direction. A display method by a display device which magnifies and projects image light formed by a display element through an intermediate screen, wherein the display element is synchronized with the movement of the intermediate screen to change the projection distance by the movement in the optical axis direction. A display method for performing display, and setting projection distances to partially overlap in adjacent display zones among a plurality of display zones for changing the projection distance.

Images