JP6315385B2 - Projection-type image display device - Google Patents

Description

  The present invention relates to a projection-type image display apparatus capable of displaying a naked-eye 3D (three-dimensional) image having continuous motion parallax with a projector that projects an image.

  A naked-eye 3D display that displays different images depending on the viewpoint position of the observer can observe realistic images without using special devices such as 3D glasses, which is extremely important for entertainment and video communication. Technology.

  A display device that displays different images depending on directions using a lenticular lens is disclosed (for example, see Patent Document 1).

  There has been disclosed a method of presenting an image that changes smoothly following a change in viewpoint position by presenting a sharp directional image (see, for example, Non-Patent Document 1). This method requires a large number of projectors and video sources, and the configuration of the display device is large. The fact that a large number of video sources are necessary means that in the case of live-action shooting, cameras are required as many as the number of video sources when special video processing is not performed. Therefore, it has been required to present a video that changes smoothly with respect to viewpoint movement with as few directivities as possible.

  In order to solve the above problems, considering the human visual characteristics, by appropriately mixing the images of adjacent cameras, even with a relatively small number of cameras, continuous motion parallax (smooth change of the image with respect to viewpoint movement) ) Is obtained (see, for example, Patent Document 2).

JP 2012-237798 A JP 2014-138306 A

Shoichiro Iwasawa, “The world's first! Realization of stereoscopic vision with 200-inch natural autostereoscopic display”, pp. 1-4, NICT NEWS No. 410, November 2011

  However, the display device according to the invention of Patent Document 2 is realized by using binocular 3D display and head tracking, and there is a problem that a special instrument called 3D glasses must be attached. Another problem is that many people cannot watch the same video at the same time.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a projection type video display apparatus that allows a large number of people to view 3D images simultaneously without using a dedicated instrument.

  The present invention includes a plurality of projectors that project the image on the side opposite to an observer who views the image with a lens interposed therebetween, and two or more images out of images projected by the plurality of projectors from the viewpoint on the observer side It is characterized in that it can be seen at the same time.

  The present invention is characterized in that when the viewpoint of the observer is moved, the total of the ratios of the light amounts of the projectors of the images projected by two or more projectors that appear to overlap each other is constant.

  The present invention is characterized in that the transmittance of the aperture of the aperture of the projector varies depending on the place where the viewer can see.

  The present invention is characterized in that the transmittance of the aperture of the diaphragm is uniform in the vertical direction and linearly varies in the horizontal direction.

  The present invention is characterized in that the diaphragm of the projector has a rhombus shape, and the lens further includes an anisotropic diffuser that diffuses light in the vertical direction.

  The present invention is characterized in that the focus of the projector is adjusted so as to form an image of the projector on the anisotropic diffuser.

  The present invention is characterized in that the focal length of the lens is set so as to form an image of the aperture of the projector at an observation viewpoint position.

  According to the present invention, there is no need to wear a dedicated instrument, and an effect that a large number of people can view 3D images at the same time is obtained.

It is a block diagram which shows the structure of 1st Embodiment of this invention. It is explanatory drawing which shows the structure of the aperture stop provided in the lens 12 of the projectors 1-9 shown in FIG. It is explanatory drawing of arrangement | positioning of the projector shown in FIG. It is explanatory drawing which shows the ratio of the brightness | luminance from each position of an observer's horizontal direction, and each projector. It is a figure which shows distribution of the brightness | luminance according to the angle to observe. It is a figure which shows distribution of the brightness | luminance according to the angle to observe. It is a block diagram which shows the structure of the projection type video display apparatus by 2nd Embodiment of this invention. It is explanatory drawing of the aperture provided in the lens 12 of the projectors 1-9. It is explanatory drawing which shows the example of arrangement | positioning of the projectors 1-9. It is explanatory drawing which shows luminance distribution which becomes convolution of a diaphragm aperture and the expansion to an up-down direction.

<First Embodiment>
Hereinafter, a projection-type image display apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, a plurality of projectors 1 to 9 are provided on the opposite side of the first lens 20 (referred to as the first lens to distinguish it from the lens provided for the projector) as viewed from the observer 30 and the lens 12 is interposed. This is a structure in which an observer views an image.

  For the sake of simplicity, some projectors (here, projectors 2, 3, 5, 6, 8, and 9) are indicated by broken lines in the drawing. The plurality of projectors 1 to 9 are designed to be in the same plane with the optical axis by a half mirror (not shown). The projectors 1 to 9 are provided with a display unit 11 and a lens 12 based on a light emission image, and form an image of the light emission image at a predetermined position. As shown in FIG. 1, the optical axes of the projectors 1 to 9 are different.

  The first lens 20 images the diaphragm of the lens 12 of the projectors 1 to 9 on one surface on the viewer side. The observer 30 can enjoy the effect of the present apparatus most when the viewpoint is on this plane, but the effect is not impaired even if the observer 30 moves slightly in the front-rear direction. The lenses 12 of the projectors 1 to 9 are focused so as to form an image at a depth position where the observer 30 should feel the image.

  Next, referring to FIG. 2, the configuration of the diaphragm provided in the lens 12 of the projectors 1 to 9 will be described. FIG. 2 is an explanatory diagram showing a configuration of a diaphragm provided on the lens 12 of the projectors 1 to 9. As shown in FIG. 2, the lenses 12 of the diaphragms of the projectors 1 to 9 have a constant transmittance in the vertical direction and linearly change in the horizontal direction. Such optical characteristics can be realized by vapor-depositing a light-absorbing material or a reflective material on a glass substrate with a different thickness depending on the location, or by changing the area of the material.

  Next, the arrangement of the projectors 1 to 9 shown in FIG. 1 will be described with reference to FIG. FIG. 3 is an explanatory diagram showing the arrangement of the projectors. The housings of the projectors 1 to 9 are not shown. The projectors are combined by a half mirror so that the apertures of projectors adjacent in the horizontal direction overlap each other by half.

  Next, with reference to FIG. 4, the horizontal position of the observer and the ratio of luminance from each projector will be described. FIG. 4 is an explanatory diagram showing the horizontal position of the observer 30 and the ratio of luminance from the projectors 1 to 9. Since the image of the stop is formed at the position of the observer 30, the distribution of light from each projector 1 to 9 is proportional to the transmittance of the stop. In FIG. 4, the aperture images overlap for the sake of convenience and are described as being shifted up and down for convenience. However, since the aperture is shifted by half, the image viewed from each viewpoint position is the light from the aperture. As shown in the following graph of FIG. 4, the total amount of light is a constant value, and the ratio between the projectors changes linearly.

  In this configuration, crosstalk between two images is actively generated, and in a general 3D display, a double image remarkably deteriorates in image quality, but when the difference between adjacent display images is small, the viewpoint is moved. On the other hand, continuous video changes are shown. As shown in Japanese Patent Application No. 2013-266751 already filed by the applicant, smooth motion parallax can be presented with the naked eye by presenting an image with small parallax between adjacent cameras.

  Here, the phenomenon described in Japanese Patent Application No. 2013-266751 will be briefly described. FIG. 5 is a diagram illustrating a luminance distribution according to an observation angle. That is, FIG. 5 is a diagram illustrating display characteristics of the projection type video display device. The vertical axis represents the luminance of the directional image. The horizontal axis indicates the angle (observation angle) at which the directional image is observed. The top row shows the luminance distribution of the image by the projector 1. The second row from the top shows the luminance distribution of the image by the projector 2. The third row from the top shows the luminance distribution of the image by the projector 3. The bottom row shows the luminance distribution of the images by the projectors 1 to 3.

  The brightness of the image by the projector 2 is the highest value at the observation angle that bisects the display area 2-2. On the other hand, the brightness of the image by the projector 2 decreases linearly according to the angle at which the image is observed, and is an observation angle that bisects the display area 2-1 adjacent to the display area 2-2. For example, the luminance value is 0). Further, the luminance of the image by the projector 2 decreases linearly according to the angle at which the image is observed, and is an observation angle that bisects the display area 2-3 adjacent to the display area 2-2 and is equal to or less than a predetermined threshold value. It has become.

  The same applies to the brightness of the image by the projector 1 and the brightness of the image by the projector 3. For example, as shown in FIG. 5, when paying attention to the projector 2, the luminance shows the maximum value at the center of the display region 2-2, becomes 0 at the center of the adjacent display regions 2-1 and 2-3, and the luminance change therebetween. Is linear.

  FIG. 6 is a diagram illustrating the relationship between the weighted average of two images and the contour position. The width of the image shift between adjacent viewpoints is 3 [arc min. When the directional image is displayed so as to have a small value, the contour position changes linearly and continuously when the weight ratio is 0 to 1, as shown in FIG. An image of an appropriate contour position was generated. That is, an intermediate viewpoint image is faithfully perceived by connecting two images having a small image shift at a linearly changing ratio.

  The mixing unit mixes the luminance distribution of the directional images for the projectors 1 to 9 with respect to the display areas 2-1 to 2-3 at a linear mixing ratio, so that the display areas 2-1 to 2-3 are changed. It will be connected smoothly. The mixing ratio is not necessarily limited to a ratio in which the luminance distribution changes linearly, and a smooth luminance distribution deviating from the linear change may be used as long as the change in the image with respect to the viewpoint movement is within an allowable range.

  By using a diaphragm with gradation transmittance that linearly changes not only in the horizontal direction but also in the vertical direction as the diaphragm, and by superimposing with a half mirror etc., the image of the diaphragm is shifted by half in the vertical direction and presented. It goes without saying that a display device capable of expressing smooth motion parallax both horizontally and vertically can be realized.

Second Embodiment
Next, a projection display apparatus according to a second embodiment of the invention will be described. FIG. 7 is a block diagram showing a configuration of a projection type video display apparatus according to the second embodiment. In the projection display apparatus according to the second embodiment, a plurality of projectors (here, projectors 1 to 9) are provided on the opposite side of the first lens 20 as viewed from the observer 30, and the first lens 20 and the diffuser are provided. This is a structure in which the viewer 30 sees an image through 40.

  In this figure, a part of the projector is represented by a broken line for easy understanding. The projectors 1 to 9 include a display element 111 and a lens 12 based on a light emission image, and form an image of the light emission image at a predetermined position. The first lens 20 forms an image of the diaphragm of the projectors 1 to 9 on a certain surface on the viewer side. The observer 30 can enjoy the effect of the present apparatus most when the viewpoint is on this plane, but the effect is not impaired even if the observer 30 moves slightly in the front-rear direction. Further, the lens 12 of the projectors 1 to 9 is focused so as to form an image on the diffuser 40 disposed between the lens 12 and the first lens 20.

  The diffuser 40 used was a diffuser having a horizontal direction of 1 degree and a vertical direction of 60 degrees as an anisotropic diffuser that diffuses light in the vertical direction and does not diffuse light in the horizontal direction. As the first lens 20, a set of two convex lenses was used, and the diffuser 40 was disposed in the middle. The second lens of the first lens is not shown.

  Next, the diaphragm provided on the lens 12 of the projectors 1 to 9 will be described. FIG. 8 is an explanatory diagram of the diaphragm provided on the lens 12 of the projectors 1 to 9 shown in FIG. As shown in FIG. 8, the lenses of the projectors 1 to 9 have a structure in which the opening amount in the vertical direction changes linearly with respect to the horizontal direction. Such optical characteristics can be easily realized by drilling holes in an opaque plate such as a metal plate.

  In addition, the aperture shape can be various as shown in FIGS. 8A, 8B, and 8C, but the shape that uses the center in the vertical direction at the periphery as shown in FIG. Can be used as effectively as possible. In FIG. 8 (a; diamond), (b: parallelogram), (c: triangle), the length of the opening is shown in the vertical direction.

  Next, an arrangement example of the projectors 1 to 9 will be described. FIG. 9 is an explanatory diagram showing an arrangement example of the projectors 1 to 9. Here, illustration of the housings of the projectors 1 to 9 is omitted. The projectors 1 to 9 adjacent in the horizontal direction are arranged so that the apertures of the projectors 1 to 9 overlap each other in the vertical direction.

  In this configuration, since the light from the projectors 1 to 9 is diffused in the vertical direction, the image formed on the surface on which the observer 30 is also diffused in the vertical direction. In other words, it becomes a convolution that expands in the vertical direction with the aperture opening, resulting in a luminance distribution as shown in FIG. Since the luminance gradation is proportional to the aperture in the vertical direction of the stop, a linear gradation can be obtained by using the aperture as shown in FIG. Therefore, the same effect as in FIG. 4 can be obtained, and smooth motion parallax can be expressed in the horizontal direction.

  Needless to say, the lens of the present application is not limited to a single lens, and may be any lens having a lens function for imaging light, such as a combination lens, a Fresnel lens, a green lens, and a zone plate.

The diffuser 40 of the present application may be installed in front of or behind the first lens 20, or may be arranged between the lens groups constituting the first lens. In addition, although LSD (Light Shaping Diffuser) is used as the anisotropic diffuser, a lenticular lens or the like may be used.
1 and FIG. 7 show the case where there is one observer 30, but there may be a plurality of observers 30. Even in this case, it is possible to view the video at the same time.

  As described above, the projection-type video display device described above can present smooth motion parallax that can be used simultaneously by many people without wearing special devices such as 3D glasses with a small number of directional video sources. A naked-eye 3D display device can be realized.

  You may make it implement | achieve all or one part of the projection type video display apparatus in embodiment mentioned above with a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included and a program held for a certain period of time. Further, the program may be a program for realizing a part of the above-described functions, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system. It may be realized using hardware such as PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

  As mentioned above, although embodiment of this invention has been described with reference to drawings, the said embodiment is only the illustration of this invention, and it is clear that this invention is not limited to the said embodiment. is there. Therefore, additions, omissions, substitutions, and other modifications of the components may be made without departing from the technical idea and scope of the present invention.

  It can be applied to applications where it is essential to view 3D images simultaneously by a large number of people.

  DESCRIPTION OF SYMBOLS 1-9 ... Projector, 11, 111 ... Display part, 12 ... Lens, 20 ... 1st lens, 30 ... Observer, 40 ... Diffuser

Claims (6)

A plurality of projectors for projecting the image on the opposite side of the observer viewing the image across the lens;
Allowing two or more images among the images projected by the plurality of projectors to be viewed simultaneously from the viewpoint on the viewer side ,
The focal length of the lens is set so as to form an image at the observation viewpoint position of the aperture of the projector,
The projection-type image display apparatus, wherein the two or more images are mixed at a predetermined ratio at the observation viewpoint position .   2. The projection type according to claim 1, wherein, when the viewpoint of the observer is moved, a total of the ratios of the light amounts of the projectors of images projected by two or more projectors that appear to overlap each other is constant. Video display device.   The projection type image display apparatus according to claim 1, wherein the transmittance of the aperture of the aperture of the projector varies depending on a place where the observer can see.   4. A projection type image display apparatus according to claim 3, wherein the transmittance of the aperture of the diaphragm is uniform in the vertical direction and linearly changes in the horizontal direction.   3. The projection display apparatus according to claim 1, further comprising an anisotropic diffuser for diffusing light in a longitudinal direction on the lens, wherein the diaphragm of the projector has a rhombus shape.   6. The projection type image display apparatus according to claim 5, wherein a focus of the projector is adjusted so as to form an image of the projector on the anisotropic diffuser.