JP2007264261A - Projection type stereoscopic display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type stereoscopic display device achieving efficient stereoscopic display by performing two or more kinds of parallactic display by one projector. <P>SOLUTION: The display device 10 is constituted of the projector 12, a mirror group for projection 14 and a directive screen 16. The projector 12 projects a projected image to the mirror group for projection 14 so as to align it with each mirror 18 of the mirror group for projection 14, and the angle of the mirror for projection 18 is adjusted each so that the light projected to the mirror group for projection 14 may be one on the directional screen 16, whereby two or more kinds of parallax are represented by one projector 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projection type stereoscopic display device capable of displaying a stereoscopic image (three-dimensional image).

  Efforts have been made to efficiently increase the number of parallaxes and the density of parallax in a stereoscopic display device. In autostereoscopic display using a projector, a plurality of projectors are arranged to increase the number of parallaxes. At that time, the parallax density could not be increased because the lens and the main body were in the way. As a method for solving this problem, a method has been proposed in which the projector is arranged not only in the horizontal direction but also in the vertical direction, and the horizontal parallax density is increased by using a screen for vertical diffusion.

For example, in Patent Document 1, a plurality of projectors are arranged two-dimensionally and assigned to horizontal parallax by vertical diffusion. In Patent Document 2, a lens is inserted into the optical system described above, and a stereoscopic image is reproduced as a set of parallel lights.
US Pat. No. 5,430,474 Japanese Patent No. 3576521

  An example of a conventional projection type stereoscopic display device (hereinafter referred to as a display device) 100 will be described with reference to FIGS.

  The display device 100 performs autostereoscopic display using the convex lens 104. FIG. 1 shows an example of directivity display by the convex lens 104.

Light projected onto the convex lens 104 by the projection lens 106 in the projector 102 is collected by the convex lens 104. The condensed image is a real image of the projection lens 106, and its width can be expressed by an effective diameter of the projection lens 106 with a magnification m determined by the projection distance and the focal length of the convex lens 104. If the focal length f and the projection distance a are here,

Magnification m = f / (a + f)

It becomes. The projected image of the projector 102 can be observed only when the real image enters the eyes of the observer.

  Projection is performed so that the two projectors 102 overlap each other on one screen, and the real images of the respective projection lenses are installed so as to enter the left and right eyes of a human. If different projection images corresponding to the right eye and the left eye can be observed, the observer can observe a stereoscopic image. This is the principle of the binocular stereoscopic display device.

  If the number of projectors 102 is increased, different images can be projected, and motion parallax can be obtained because the images change depending on the viewing position. This is multi-view stereoscopic display.

  However, when such a display device 100 is configured, the density of an image that can be observed is determined by the distance between the projection lenses 106 of the projector 102. It is difficult to project the projection lenses 106 side by side without a gap. If a gap is formed, a place that cannot be observed is created.

  Therefore, a method using a vertical diffusion screen has been used as in Patent Documents 1 and 2. FIG. 2 shows changes in element viewing areas (respective ranges in which the projected image can be observed) due to the vertical diffusion screen. As shown in FIG. 3, a plurality of projectors 102 are arranged not only horizontally but also vertically. At that time, when the convex lens 104 is projected as a screen, the element viewing areas (real images of the projection lens 106) are scattered horizontally and vertically as shown in FIG.

  For example, when a lenticular sheet with ridgelines placed horizontally is superimposed on the convex lens 104, the action of vertical diffusion is added, resulting in FIG. 2B. At this time, the effect of the convex lens 104 can be not only condensed but also parallel light. In addition, a three-dimensional image can be displayed by creating a projection image as a set of light rays, whether condensed, divergent light, or parallel light.

  However, when this method is used, a plurality of projectors 102 or projection lenses 106 are required.

  Therefore, the present invention provides a projection type stereoscopic display device that performs a plurality of parallax displays and efficiently performs a stereoscopic display.

  The present invention includes a projection unit that projects a projection image, a projection mirror group that reflects the projection image, and a directional screen that projects the reflected projection image, and the projection unit displays parallax. Projecting images in which the same number of parallax images are arranged vertically and horizontally are projected, and the projection mirror group has (1) a number of projection mirrors equal to the number of parallax images, and (2) the plurality The projection mirrors are arranged vertically and horizontally, and (3) the projection mirrors are projected onto the directional screen so that the parallax images reflected by the projection mirrors are projected together. The projection type stereoscopic display device has different angles with respect to an optical axis of the projection image from the projection unit.

  According to the present invention, by using a mirror optical system, a plurality of parallax displays can be performed, and a stereoscopic display can be performed efficiently.

  A projection type stereoscopic display device (hereinafter simply referred to as a display device) 10 according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
The display apparatus 10 of 1st Embodiment is demonstrated based on FIG. 4 and FIG.

  FIG. 4 shows a side view of the display device 10 of the present embodiment, and FIG. 5 shows a projected image and a projection mirror group 16.

  As shown in FIG. 4, the display device 10 includes a projector 12, a projection mirror group 14, and a directional screen 16.

  The directional screen 16 is a vertical diffusion screen that has a strong diffusion effect in the vertical direction and a low horizontal direction.

  As shown in FIG. 5 (a), the projected image has 12 parallax images displayed separately on one screen, and has a lattice pattern of 3 columns vertically and 4 rows horizontally. The horizontal position is shifted for each step in the vertical direction, and the parallax differs depending on the position of the horizontal position. That is, the projected image is arranged by shifting four parallax images arranged in the horizontal direction for each vertical step, and by arranging three parallax images arranged in the vertical direction in an inclined manner, The centers of the parallax images are different horizontal coordinates. In FIG. 5, twelve parallax images with circle numbers 1 to 12 are displayed. The parallax angle corresponds to the horizontal image position. Equally spaced parallax angles can be displayed by shifting evenly.

  The projection mirror group 14 is as shown in FIG. 5B, and has a shape and arrangement corresponding to the projection image. That is, twelve projection mirrors 18 equal to the number of parallax images are provided. A plurality of projection mirrors 18 are arranged vertically and horizontally in a lattice form of three rows vertically and four rows horizontally. In the projection mirror group 14, the four projection mirrors 18 arranged in the horizontal direction are arranged so as to be shifted for each vertical stage, and the three projection mirrors 18 arranged in the vertical direction are inclined in order. Thus, the projection mirror group 14 as a whole is formed so that the horizontal coordinates are evenly shifted. Further, the projection mirrors 18 are respectively projected with respect to the optical axis of the projection image from the projector 12 so that the parallax images reflected by the projection mirrors 18 are projected onto the directional screen 16 as one. With different angles. That is, the angle of the projection mirror 18 is adjusted so that the light projected onto the projection mirror group 14 becomes one on the directional screen 16.

  The projector 12 projects the twelve parallax images of the projection image described above onto the twelve projection mirrors 18 of the projection mirror group 14, respectively.

  By doing so, the display device 10 of the present embodiment can express a plurality of parallaxes on the directional screen 16 with one projector 12.

  Also, as a variant form of the first embodiment, it is possible to perform stereoscopic display with parallax horizontally and vertically by controlling the diffusibility in the vertical direction and arranging the parallax so as not to mix up and down. .

(Second Embodiment)
A display device 10 according to the second embodiment will be described with reference to FIGS. 6 to 10, 14, and 15.

(1) Configuration of Display Device 10 FIG. 6 shows a side view of the display device 10 of the present embodiment, FIG. 7A shows a projection shift mirror group 20, FIG. 7B shows a projection mirror group 22, and FIG. 7 (c) shows a projected image.

  In the second embodiment, another projection shift mirror group 20 is added to the display device 10 of the first embodiment. That is, the display device 10 includes the projector 12, the projection shift mirror group 20, the projection mirror group 22, and the directional screen 16. In the first embodiment, each of the twelve parallax images as shown in FIG. 5A is a projection image arranged in a shifted manner in the horizontal direction, and a useless part is inevitably formed in the projection image. . In the second embodiment in which a projection shift mirror is added, twelve parallax images as shown in FIG. 7 (c) have a rectangular shape arranged vertically and horizontally in a grid pattern, eliminating unnecessary gaps in the projected image. Can do.

  The projection mirror group 22 has the same structure as the projection mirror group 14 of the first embodiment, and is composed of 12 projection mirrors 26 in the case of 12 parallax as shown in the example.

  The projection shift mirror group 20 is composed of m projection shift mirrors 24 in the vertical direction when the parallax image has m stages. Since the form of the parallax image shown in the example is three stages, in FIG. 7A, there are three sheets of 24A, 24B, and 24C. In the projection shift mirror group 20, the vertical axis 25 rotates in accordance with the horizontal shift amount of the projection mirror group 22. As a result, the rectangular projection image can be projected onto each vertical region of the projection mirror group 22 shifted in the horizontal direction.

In the example of this embodiment, the number of projection mirrors 26 is twelve, but when the number of projection mirrors 26 is n ² (n is a natural number), the aspect ratio of the projected image is the aspect ratio of the projection projector. Is played almost equally.

  The directional screen 16 has directivity and has strong diffusibility particularly in the vertical direction. The parallax images (element images) arranged in blocks by the two-stage mirror groups 20 and 22 are divided to have directivity and recombined on the directivity screen 16. In the projected image, the parallax image is arranged as it is in a block shape, and noise during compression of the image has little influence on the stereoscopic image with respect to an image to which parallax is assigned to each adjacent pixel of the image.

(1) Spread of light FIG. 8 shows the positional relationship among the projector 12, the directional screen 16, and the observer.

  The projection distance from the projector 12 is L1, the effective diameter of the projection lens 28 of the projector 12 is d, and the viewing distance from the directional screen 16 (convex lens and lenticular lens) to the observer is L2.

When projecting with a large number of projectors 12, the observer can observe a directional image without any gaps by filling at least the effective diameter interval of the projectors 12 without gaps in the horizontal direction. It is also possible to widen the interval by adding horizontal diffusion in the directional screen 16. The spread of light θr in the horizontal direction can be expressed by Equation (1) when there is no horizontal diffusion action of the directional screen 16.

(2) Mirror Arrangement FIG. 9 shows a top view of the positional relationship between the projection mirror group 22 and the directional screen 16.

  FIG. 10 shows a side view of the positional relationship among the directional screen 16, the two mirror groups 20 and 22, and the projector 12. The distance from the projector 12 to the projection shift mirror group 20 is d1, the distance from the projection shift mirror group 20 to the projection mirror group 22 is d2, and the distance from the projection mirror group 22 to the directional screen 16 is c. And That is, d1 + d2 + c = L1. The mirror size of the projection mirror 26 of the projection mirror group 22 is a for horizontal and b for vertical. Since the arrangement of the projection mirror group 22 corresponds to the parallax interval, in order to give a uniform parallax interval, the deviation of the horizontal position of the projection mirror 26 must be given at an interval of a / m in the case of m stages vertically. There is.

Further, the angle range 2θ in which the stereoscopic image can be displayed by the directional screen 16 and the projector 12 can be determined from the horizontal size a of the projection mirror group 22 and the distance c to the directional screen 16. Equation (2) shows the relational expression. Here, the vertical m stages and the horizontal n stages are used.

The mirror size of the projection mirror 26 can be determined by the projection magnification k. Projection width = projection distance / k.

The distance c between the projection mirror and the screen can be derived from the relationship between the expressions (2) and (3).

(3) Luminance unevenness on the directional screen 16 When the image is divided by the mirror before the image is formed, the edge of the mirror is blurred. FIG. 14 is a diagram for explaining uneven brightness on the directional screen 16.

This luminance unevenness is greatly affected by the projection shift mirror group 20. The size x1 of the blur on the projection shift mirror group 20 is the effective diameter d of the projection lens of the projector 12, the distance d1 between the projection shift mirror group 20 and the projector 12, and the projection shift mirror group 20 to the projection mirror group. When expressed using a distance d2 to 22, a distance c from the projection mirror group 22 to the directional screen 16, and a projection distance L1, the following expression is obtained.

The edge of the mirror is reflected as this blur amount x1, and is magnified and projected on the directional screen 16. The magnitude x of luminance unevenness on the directional screen 16 can be expressed by the following equation. Note that the vignetting of the image by the edge of the mirror is half the amount of the blur, so that the coefficient is ½.

The ratio of the width x of the unevenness to the width D of the image projected on the directional screen 16 is

It becomes.

  Brightness unevenness can be eliminated by creating a screen that is as small as this ratio for one parallax image.

(4) Angle of Mirror As shown in FIG. 7A, the rotation angle θ1 (horizontal rotation) with the vertical axis of the projection shift mirror group 20 as the rotation axis 25 can be expressed by the following equation.

  The mirror angle of the projection mirror group 22 can also be obtained from the respective coordinates and the light beam angle from the projection shift mirror group 20.

(5) Fine adjustment and distortion correction The angle of the projection mirror 26 and the projection shift mirror 24 can be moved, and the position and angle can be adjusted using the test image. An example of alignment using a test image will be described based on the flowchart of FIG.

  In step 1, the projection mirror group 22, the projection shift mirror group 20, the projector 12, and the directional screen 16 are installed so as to be aligned with each other.

  In step 2, the projection mirror group 22 is shifted by a / m for each stage.

  In step 3, a block-like test image (test pattern) is projected from the projector 12, and the position of the projection shift mirror 24 is moved so that the parallax image enters the entire projection shift mirror group 20.

  In step 4, when the center of the projection mirror group 22 and the center of the projection image are aligned, the horizontal angle of the projection shift mirror group 20 is rotated to match the deviation of the projection mirror group 22.

  In step 5, a diffusion plate whose center position is known is stretched on the directional screen 16, and the angle of the projection mirror group 22 is adjusted while projecting a test image indicating the center position of the parallax image.

  The center position can be adjusted by the mirror angle, but the distortion due to the difference in projection angle cannot be adjusted. Distortion can be corrected by the projected angle and the projection distance of each parallax image.

  It is also possible to correct distortion by feeding back a test image while photographing with a camera.

(Third embodiment)
A display device 10 according to a third embodiment will be described with reference to FIG.

  In the first embodiment and the second embodiment, an image is displayed by projecting on the directional screen 16 set up vertically. For this reason, when the lens center and the projection center are equal, the light beam has an angle as it is, so that it is observed to look down a little.

  Therefore, in the present embodiment, the light can be observed from the front of the directional screen 16 by bending light with a prism sheet or shifting the projection center from the lens center.

  FIG. 11 is a side view in which the center of the lens is shifted and observed in front of the directional screen 16. As shown in FIG. 11, when the lens center is projected so that the projection center passes at the position of the focal length, it can be observed in front.

(Fourth embodiment)
A display device 10 according to a fourth embodiment will be described with reference to FIG.

  It is also possible to display a stereoscopic image from a desk-like display by placing the directional screen 16 horizontally and projecting it obliquely from below.

  FIG. 12 shows the flat display device 10.

  Further, it is possible to project from obliquely upward using the reflective directional screen 16. For example, it can be projected from obliquely above a convex lens and a lenticular sheet sandwiching a mirror.

  Even if the projection image is subjected to image processing corresponding to the shape of the directional screen 16, the wall surface and the floor surface are made the directional screen 16, and a three-dimensional image can be displayed by projecting. The directional screen 16 may be a curved surface instead of a flat surface, and may be, for example, a cylindrical or spherical directional screen 16.

(Fifth embodiment)
A display device 10 according to a fifth embodiment will be described with reference to FIG.

  The parallax and the display range can be increased by using a plurality of projectors 12. For example, in the case of flat stereoscopic display, different stereoscopic images can be shown to the viewers who face each other using two sets of projection optical systems.

(Sixth embodiment)
A display device 10 according to a sixth embodiment will be described.

  When a plurality of projectors 12 are used, the projection shift mirror group 20 can be used in common. At this time, if the arrangement of the projector 12 is adjusted to a projection angle proportional to the number of mirrors, projection can be performed without a gap.

(Seventh embodiment)
A display device 10 according to a seventh embodiment will be described.

  It is also conceivable to rotate the projection shift mirror group 20 and the projection mirror group 22. At this time, the projection mirror group 22 is rotated at a speed twice that of the projection shift mirror group 20. As a result, the correspondence between the mirrors 24 and 26 is always equal. The directional screen 16 can also be rotated together.

  When the directional screen 16 is horizontally placed and displayed as a flat display, the directional screen 16 can be rotated about the normal line of the directional screen 16 as a rotation axis like a record.

It is explanatory drawing which shows the example of the directivity display by the conventional convex lens. It is explanatory drawing of a vertical diffusion screen. It is the front view which arranged the some projector. It is a side view of the display apparatus of the 1st Embodiment of this invention. It is a figure which shows the projection image and projection mirror group of 1st Embodiment. It is a side view of the display apparatus of 2nd Embodiment. It is a figure which shows the projection image and both mirror group of 2nd Embodiment. It is explanatory drawing which shows the positional relationship of a projector, a directional screen, and an observer. It is explanatory drawing which shows the positional relationship of a projection mirror group, a directional screen, and an observer. It is a side view which shows a projector, both mirror groups, and a directional screen. It is explanatory drawing of the display apparatus of 3rd Embodiment. It is explanatory drawing of the display apparatus of 4th Embodiment. It is explanatory drawing of the display apparatus of 5th Embodiment. It is explanatory drawing of a brightness nonuniformity. It is a flowchart for performing adjustment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Display apparatus 12 Projector 14 Projection mirror group 16 Directional screen 18 Projection mirror 20 Projection shift mirror group 22 Projection mirror group

Claims (21)

A projection unit that projects a projection image, a projection mirror group that reflects the projection image, and a directional screen that projects the reflected projection image;
The projection unit projects a projection image in which a number of parallax images equal to the number of parallaxes to be displayed are arranged vertically and horizontally,
The projection mirror group includes:
(1) having a number of projection mirrors equal to the number of parallax images;
(2) The plurality of projection mirrors are arranged vertically and horizontally,
(3) The optical axes of the projection images from the projection unit are projected so that the parallax images reflected by the projection mirrors are projected onto the directional screen as one. Projection-type stereoscopic display device characterized by having different angles with respect to each other. The projection mirror group includes:
The projection type stereoscopic display device according to claim 1, wherein center coordinates of the projection mirror have different coordinates in the horizontal direction. The projection mirror group includes:
The projection type stereoscopic display device according to claim 1, wherein center coordinates of the projection mirror have different coordinates at equal intervals in the horizontal direction. The projection mirror group includes:
The projection type stereoscopic display device according to claim 1, wherein center coordinates of the projection mirror have different coordinates at equal intervals in the vertical direction and the horizontal direction. The projection according to claim 2, wherein the central coordinates of the projection mirror are arranged in rows in the vertical direction, the rows are arranged at equal intervals, and the horizontal direction has different coordinates at equal intervals. Type 3D display device. A projection shift mirror group between the projection unit and the projection mirror group;
The projection unit projects a projection image composed of parallax images arranged horizontally and vertically in a grid pattern,
The projection shift mirror group includes:
(1) A number of projection shift mirrors equal in number to the vertical direction of the projection mirror group are arranged in a vertical direction,
(2) The projection shift mirror at each stage reflects the parallax images from the projection unit to the projection mirrors arranged in series with different coordinates in the horizontal direction. The projection type stereoscopic display device according to claim 2. The projection type stereoscopic display device according to claim 1, wherein the directional screen has higher diffusivity in the vertical direction than in the horizontal direction. The projection type stereoscopic display device according to claim 1, wherein the directional screen is disposed on a vertical plane. The projection type stereoscopic display device according to claim 1, wherein the directional screen is disposed on a horizontal plane. The projection type stereoscopic display device according to claim 1, wherein the directional screen is disposed at an angle substantially perpendicular to a projection angle. The projection type stereoscopic display device according to claim 1, wherein the directional screen is a curved surface. The projection type stereoscopic display device according to claim 1, wherein the directional screen is rotatable. The projection type stereoscopic display device according to claim 7, wherein the directional screen is rotatable about a normal line of the directional screen as a rotation axis. (1) The relative position of the projection mirror and the projection shift mirror is fixed,
(2) The projection mirror and the projection shift mirror are rotatable about a vertical axis passing through the center of the directional screen as a rotation axis,
(3) The projection type stereoscopic display device according to claim 1, wherein the projection mirror rotates about the rotation axis at a rotational speed twice that of the projection shift mirror. The projection type stereoscopic display device according to claim 1, wherein the number of projection mirrors is n ² . The projection type stereoscopic display device according to claim 1, further comprising a plurality of projection units that project onto the one projection mirror group. The projection type stereoscopic display device according to claim 1, wherein the projection type stereoscopic display device includes a plurality of projection units that commonly project and use the one projection shift mirror group. The directional screen is one piece,
The projection type stereoscopic display device according to claim 1, wherein there are a plurality of sets of projection mirror groups corresponding to the projection unit. The projection type stereoscopic display device according to claim 1, further comprising a correcting unit that corrects the projected image by using a test image for distortion of the image caused by the projection. The projection type stereoscopic display device according to claim 6, wherein each of the parallax images is configured to be smaller than a size of the projection shift mirror by a predetermined ratio. The predetermined ratio is

x / D = k · d (c + d) · L1 · 2 · d1

X is the width of the uneven brightness, D is the width of the image, k is the projection magnification, d is the effective diameter of the projection lens of the projection unit, d1 is the distance between the projection shift mirror group and the projection unit, c The projection type stereoscopic display device according to claim 20, wherein is a distance from the projection mirror group to the directional screen, and L1 is a projection distance from the projection unit.

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