JP4728825B2 - 3D image display device - Google Patents

Description

  The present invention relates to a technique for displaying a stereoscopic image, and more particularly to an IP (Integral Photography) type stereoscopic image display apparatus.

  2. Description of the Related Art In recent years, development and examination of methods that do not use polarized glasses, shutter glasses, and the like have been actively conducted as stereoscopic image methods for displaying stereoscopic images. Most of these, except for the holography method, are a combination of a flat panel display such as a liquid crystal display that displays normal two-dimensional images, a lenticular screen, a parallax barrier, a pinhole, or a two-dimensional lens array. is there. These are capable of observing a stereoscopic image without using glasses, and can form not only a binocular system that displays two types of parallax images corresponding to the left and right eyes, but also a multi-view system of 3 or more eyes.

  Conventionally, a method using a lens plate (lens array) (lens plate method) uses one in which pinholes and lenses are two-dimensionally arranged as a lens plate, and is one of stereoscopic video methods that can be viewed from an arbitrary viewpoint. It is known as an IP system.

  Hereinafter, a case where a lens plate is used in this IP method will be described with reference to FIG. FIG. 10 is an explanatory diagram for explaining the conventional IP system, (a) is a schematic diagram schematically showing a configuration of an apparatus for taking an IP image by the conventional IP system, and (b) is a conventional IP system. It is a schematic diagram which shows typically the structure of the apparatus which displays a three-dimensional image by a system.

  As shown in FIG. 10A, the photographing apparatus 100 includes a lens group (lens plate) 101 including a plurality of lenses (convex lenses) l, l,... Arranged in an array on the same plane, and the lens group. The imaging unit 102 is installed behind the camera 101, and the subject S installed in front of the lens group 101 is photographed. In this imaging unit 102, images I, I,... Of the subject S are formed by the lenses 1, 1,. Each image I, I,... Of the subject S photographed here is called an element image.

  Next, as shown in FIG. 10B, the display device 110 includes a lens group 111 (lenses l ′, l ′,...) That is the same as the lens group 101 of the photographing apparatus 100 [FIG. When the image captured by the photographing apparatus 100 is displayed on the display unit 112, the display unit 112 includes a display unit 112 installed behind the group 111 at the same position as the imaging unit 102. A stereoscopic reproduction image S ′ of the subject S can be observed. Here, the video information (brightness and color) of the stereoscopic reproduction image S ′ observed from the observer O is obtained by viewing the subject S from the lens group 101 or the imaging unit 102 side (rear side) at the time of shooting, and the depth ( (Unevenness) is viewed from the observer O side (front side) during photographing. Therefore, the stereoscopic image does not become a correct stereoscopic image of the subject S, but becomes a stereoscopic reproduction image S ′ (reverse depth image) whose depth is inverted.

  In order to solve this, it is necessary to capture the stereoscopic reproduction image S ′ displayed by the display device 110 again by the imaging device 100 and display the element image group captured here on the display device 110. It is also possible to perform the process of re-photographing the stereoscopic reproduction image S ′ by electronic conversion processing. That is, each element image is inverted so as to be point-symmetric about the position of the optical axis of each corresponding lens l, l,. It has been reported that this element image conversion processing is performed as graphic conversion (see Non-Patent Document 1). Further, a method is disclosed in which an image is optically inverted by using a fiber optical system for the lenses l, l,... Of the photographing apparatus 100 (see Patent Document 1). According to this method, re-photographing and electronic conversion processing are not required.

  Further, when displaying the element image group by electrical means, an LCD (Liquid Crystal Display; liquid crystal display, not shown) capable of displaying a high-definition image for displaying a large number of element image groups is provided. It is installed at the position of the display unit 112 in FIG.

  Also, instead of using a direct view type FPD (Flat Panel Display), an element image group is projected on a screen (not shown), and a lens group (not shown) is provided on the back side of the projected side. It is good also as installing. At this time, the observer O can observe a stereoscopic image by observing the element image group from the back side through the lens group. An example in which a plurality of projected images are connected to improve resolution (total number of pixels) has been reported (see Non-Patent Document 2). Note that the IP display device is limited to projection from the back surface because the lens group needs to be installed close to the screen.

  Here, a rear projection type image device (projector) and a screen on which an image is projected will be described. The projector (not shown) includes an electronic display device such as a liquid crystal display panel as display means, and projects and displays an image displayed on the display means on a screen (not shown) via a projection lens. Let me image. The screen has a diffusing characteristic, and the projected image is observed from the opposite side of the projector. Here, a ground glass-like thing can be used as a diffusion plate (screen). This diffusing plate has isotropic diffusibility and can secure a viewing zone that is an observable range over a wide range, but the amount of light is insufficient. In addition, since it is usually important to secure the viewing zone in the horizontal direction, a lenticular lens screen can be used as the diffusion plate. This diffusion plate has diffusion characteristics only in the horizontal direction.

  Further, as shown in FIG. 11, in order to secure the amount of light in the viewing zone, the screen C has a Fresnel lens if as a condensing lens for condensing light from the projector P, and isotropic diffusion layer. A diffusion plate having a diffusion plate (diffusion plate B1) and a horizontal diffusion material (diffusion plate B2) such as a lenticular lens screen is also used. FIG. 11 is a schematic diagram schematically showing an example of the structure of the rear projection type video apparatus and the screen.

  Such a configuration of the rear projection projector P and the screen C is applied to the display unit 112 of the IP display device 110 shown in FIG. 10, so that the display unit 112 is the same as the case of the direct-view display screen. The stereoscopic reproduction image S ′ can be displayed. Here, in the IP display device 110, since it is necessary to display the element image group on the display unit 112 with high definition, it is necessary for normal 2D video display on the screen on which the element image group is projected. It is necessary to secure a finer definition than the performance. Here, when a lenticular lens screen is used as the diffusion plate of the screen, the resolution is limited by the pitch of the lenticular lens, which is not preferable. On the other hand, it is possible to use an isotropic diffusing material for the screen diffusing plate, and an example in which a diffusing material with improved resolution characteristics is used for the screen of a projector has been reported (see Non-Patent Document 2).

  Furthermore, in the IP display device 110, as shown in FIG. 12A, one lens image lm in the lens group 111 corresponds to one element image Gm, and the observer O transmits the element image through the lens lm. Observe part of Gm. FIG. 12 is an explanatory diagram for explaining the relationship between the element image, the lens, and the viewing area, FIG. 12A is a schematic diagram schematically showing the viewing area determined by the arrangement of the element image and the lens, and FIG. These are the schematic diagrams which show typically the example of a false visual field.

Here, since the element image Gm and the lens lm are approximately spaced apart by the focal distance f _{A of the} lens lm, the viewing zone is determined by the size of the element image Gm and the focal distance f _A. And the width | variety and arrangement | positioning of the element image Gm from which the width | variety of a visual field becomes the maximum in a specific observation distance are reported (refer nonpatent literature 3).

Also, as shown in FIG. 12B, the observer O can also obtain a stereoscopic image (not shown) by passing the element image Gm through lenses adjacent to the corresponding lens lm (lens lm−1, lm + 1 in FIG. 12). Can be observed. FIG. 12B shows the case where the lens lm corresponding to the element image Gm is viewed from the left and right adjacent lenses lm−1 and lm + 1, but for example, a vertically adjacent lens (not shown), The element image Gm can be observed from a plurality of adjacent lenses, and there is a possibility of forming a viewing zone (false viewing zone). As described above, in the display device 110, not only a correct viewing zone according to the original design but also a number of false viewing zones are formed in the periphery.
JP-A-10-150675 (paragraph numbers 0010 to 0076) Mitsuho Yamada, “Integral 3D TV”, Monthly Display, vol. 7, no. 6, p. 29-34, June 2001 Jung-Hong, 6 others "Development of multi-projection integral videography 3D image display device", IEICE Transactions, Vol.J87-D-II, No.12, pp.2198-2208, 2004 H. Hoshino, et al., "Analysis of resolution limitation of integral photography", Journal of the Optical Society of America, A, Vol.15, No.8, pp.2059-2065, 1998

  However, in order to ensure a sufficient resolution in the generated stereoscopic video in the IP display device, it is necessary to increase the resolution of each element image, while allowing a plurality of people to observe a stereoscopic image. Requires a screen size of 50 inches to 100 inches or more instead of the usual screen size of about 10 to 20 inches. And, with a direct-view display that is mainly used at present, it is impossible to achieve both a large screen and a sufficient resolution.

  In addition, when an element image is projected onto a screen by a projector, it is easy to enlarge the screen, but since the light beam spreads when passing through the diffusion plate of the screen, a reduction in resolution is inevitable. Therefore, a screen that does not cause deterioration in resolution has been desired.

  In addition, since the false viewing zone is generated, there is an advantage that a stereoscopic image can be observed simultaneously by a plurality of persons. However, when observed from the false viewing zone, the observed stereoscopic image has a geometrical shape. Distortion occurs, or so-called reverse vision, in which the depth is reversed when observed across the boundary of the viewing zone. Therefore, in order to reproduce a correct stereoscopic image, it is desirable that the observation can be limited to the correct viewing zone. For this reason, there is a need for a restriction such that observation can be performed only in the viewing zone that is the design target, and other derivative false viewing zones cannot be seen.

  The present invention has been made to solve the above-described problems of the prior art, and does not deteriorate the resolution of the element image group projected from the projector, and does not produce a false viewing zone. An object is to provide an apparatus.

In order to solve the above problem, the stereoscopic image display apparatus according to claim 1 includes a display unit that displays an element image group including a plurality of element images captured by an integral photography type imaging apparatus, and the display unit. A projection lens that projects the light incident from the projector, and projects light from the projection device that projects the element image group and forms an image of the element image group on the same plane, thereby displaying a stereoscopic image. A stereoscopic image display device that collects light from the projection device, or condensing optical system that converts the light into parallel light, and light from each of the elemental images is incident, and each of the images A plurality of first element optical lens systems that collect light from a point or make parallel light are orthogonal to the optical axis of the first element optical lens system and the optical axis of the condensing optical system. Arranged in an array on the same plane And a lens group, the focusing distance of the optical system and the projection lens Ri der focal distance or more of the condensing optical system, the first the aperture of the lens component system D _A, wherein the condensing When the distance between the optical system and the first element optical lens system is b, the aperture of the projection lens is D _P , and the distance between the projection lens and the condensing optical system is a, The relationship of D _A / b ≦ D _P / a was satisfied .

According to such a configuration, the stereoscopic image display device collects the divergent light from the projection device by the condensing optical system, or converts the light into parallel light, and images of a plurality of element images formed on a certain plane. Are incident on the corresponding first element optical lens systems. As a result, the observer observes a part of the images of the plurality of element images via the first lens group, so that the stereoscopic image display device displays the stereoscopic image indicated by the projected element image to the observer. Can be displayed. In addition, the stereoscopic display device can limit generation of a false viewing zone by satisfying the relationship of D _A / b ≦ D _P / a.

Furthermore, the stereoscopic image display device according to claim 2 is a display unit that displays an element image group including a plurality of element images picked up by an integral photography type imaging device, and light incident from the display unit. and a projection lens for projecting, is incident light from the projection device for forming an image of the element images on the same plane by projecting the element images, stereoscopic image display device for displaying a stereoscopic image A light collecting optical system for condensing the light from the projection device or making it a parallel light, and light from the image of each of the element images are incident, and the light from each point of the image is incident A plurality of first element optical lens systems for condensing or collimating light are on the same plane orthogonal to the optical axis of the first element optical lens system and the optical axis of the condensing optical system. A first lens group arranged in an array, and each A plurality of second element optical lens systems that emit light incident from each of the element image images only to the corresponding first element optical lens system, Second array arranged in an array on the same plane that is orthogonal to the optical axis of the second element optical lens system and the optical axis of the condensing optical system and on which an image of the element image group is formed. lens and a group, the distance between the condensing optical system and the projection lens Ri der focal distance or more of the condensing optical system, the diameter of D _P of the projection _lens, the projection lens and the second the distance between the lens component system a, the first lens component system and the aperture of the second lens component system D _a, if the focal length of the focusing optical system is f _a, and Therefore, the relationship of D _P / a ≦ D _A / f _A is satisfied .

  According to such a configuration, the stereoscopic image display device condenses the divergent light from the projection device or makes it parallel light by the condensing optical system. Further, the light emitted from the projection device enters the second lens group, and forms an element image at the position of each second element optical lens system. Then, the stereoscopic image display apparatus refracts the incident light by each of the second element optical lens systems and emits only to the corresponding first element optical lens system. As a result, the observer observes a part of the images of the plurality of element images via the first lens group, so that the stereoscopic image display device displays the stereoscopic image indicated by the projected element image to the observer. Can be displayed.

A stereoscopic image display device according to a third aspect is the stereoscopic image display device according to the second aspect, wherein an arrangement interval of the first element optical lens systems in the first lens group, and the second An arrangement interval of the second element optical lens systems in the lens group is the same, and the condensing optical system is provided between the first lens group and the second lens group, and The distance between the optical optical system and the projection lens is greater than the focal length of the condensing optical system.

  According to this configuration, in the stereoscopic image display device, the light emitted from the projection device enters the second lens group, and forms an image of the element image on each second element optical lens system. Then, the stereoscopic image display device refracts the incident light by each second element optical lens system. Further, the stereoscopic image display device condenses the light emitted from the second element optical lens system by the condensing optical system. This light is incident on the first lens group. Here, since the condensing optical system is installed at a position far from the focal length of the condensing optical system from the projection apparatus, the light emitted from the condensing optical system converges. Accordingly, it is possible to widen the viewing zone, which is a region where all of the regions where the element images are seen from the observer via the respective first element optical lens systems overlap.

Furthermore, the stereoscopic image display device according to claim 4 is the stereoscopic image display device according to claim 2, wherein an arrangement interval of the first element optical lens systems in the first lens group is set to the second element group. Narrower than the arrangement interval of the second element optical lens systems in the lens group, the second lens group is provided between the first lens group and the condensing optical system, The distance from the projection lens is greater than the focal length of the condensing optical system.

  According to such a configuration, the stereoscopic image display device condenses the light diverging from the projection device by the condensing optical system, and the light emitted from the condensing optical system is incident on the second lens group, An image of the element image is formed on the second element optical lens system. Then, the stereoscopic image display apparatus refracts the light incident by each of the second element optical lens systems and emits only to the corresponding first element optical lens system. Here, since the condensing optical system is installed at a position far from the focal length of the condensing optical system from the projection apparatus, the light emitted from the condensing optical system converges. Accordingly, it is possible to widen the viewing zone, which is a region where all of the regions where the element images are seen from the observer via the respective first element optical lens systems overlap.

  The stereoscopic image display device according to the present invention has the following excellent effects. According to the first aspect of the present invention, since a stereoscopic image can be displayed without using a diffusion plate even when an element image is projected by the projection device, the resolution of the element image is not lowered and high quality is achieved. A stereoscopic image can be displayed. Since the element image is projected by the projection device, the screen can be enlarged.

  According to the second aspect of the present invention, since a stereoscopic image can be displayed without using a diffusion plate even when an element image is projected by the projection device, the resolution of the element image is not lowered and high quality is achieved. A stereoscopic image can be displayed. Since the element image is projected by the projection device, the screen can be enlarged. Furthermore, since the second element optical lens system emits light from the image of the element image only to the corresponding first element optical lens system, the amount of light can be secured and the occurrence of false viewing zones can be suppressed. be able to.

  According to the third and fourth aspects of the invention, the generation of a false viewing zone can be suppressed, and a stereoscopic image display device with a wide viewing zone can be provided. Therefore, the observer can observe the stereoscopic image displayed by the stereoscopic image display device from a wide range.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Configuration of stereoscopic image display system (first embodiment)]
First, with reference to FIG. 1, the structure of the three-dimensional image display system 1 provided with the three-dimensional image display apparatus 3 which is 1st embodiment of this invention is demonstrated. FIG. 1 is a schematic diagram schematically showing a configuration of a stereoscopic image display system including a stereoscopic image display device according to the first embodiment of the present invention. Here, an optical path of light from a pixel at the center of a certain element image among a plurality of element images displayed on the display unit 21 is schematically illustrated.

  The stereoscopic image display system 1 projects a group of element images and displays a stereoscopic image. The stereoscopic image display system 1 includes a projector 2 and a stereoscopic image display device 3.

  The projector (projection device) 2 projects an element image group. The projector 2 includes a display unit 21 and a projection lens 22.

  The display means 21 is, for example, an electronic display device such as a liquid crystal display panel or a micromirror device (DMD: Digital Micromirror Device, DLP: Digital Light Processing). On this display means 21, an element image group is inputted and displayed. The light from the element image group displayed here is incident on the projection lens 22.

  The projection lens 22 projects the light incident from the display unit 21 onto the stereoscopic image display device 3. Here, the projection lens 22 is composed of, for example, a convex lens.

  The element image group is an image for displaying a stereoscopic image by the IP system, and a plurality of element images corresponding to each of the first lens group 33 and the second lens group 32 of the stereoscopic image display device 3 to be described later. Have element images. For example, the group of element images may be captured by a conventional IP imaging apparatus as shown in FIG. 10 or may be generated by computer graphics. Since the projector 2 performs rear projection, it is assumed that necessary reversal processing is performed on the element image.

  The stereoscopic image display device 3 displays a stereoscopic image from the light of the element image group projected from the projector 2. Here, the stereoscopic image display device 3 includes a convex lens 31, a second lens group 32, and a first lens group 33.

The convex lens (condensing optical system) 31 condenses the light incident from the projector 2. The convex lens 31 is provided on the same optical axis A as the projection lens 22, and all of the light projected from the projection lens 22 enters the convex lens 31. Here, the convex lens 31 is installed at a position separated from the projection lens 22 by the focal length f _{C of the} convex lens 31. Thereby, the light passing through the principal point of the projection lens 22 is converted into parallel light by the convex lens 31.

  The second lens group 32 includes a plurality of convex lenses L2, L2,... Arranged in an array on the same plane orthogonal to the optical axis A of the convex lens 31 on which an image of an element image projected from the projector 2 is formed. Composed.

The convex lens (second element optical lens system) L2 emits light projected from the projector 2 and incident via the convex lens 31 only to the corresponding convex lens L1 of the first lens group 33 described later. . Here, each convex lens L2 corresponds to each of the plurality of element images displayed on the display means 21 of the projector 2, and further corresponds to each of the plurality of convex lenses L1 of the first lens group 33. Further, lens L2 is placed in spaced by the focal length f _A of the corresponding convex lens L1 and the lens L1 in the optical axis direction position. Further, here, the arrangement interval of the convex lenses L1 of the first lens group 33 is equal to the arrangement interval of the convex lenses L2 of the second lens group 32, that is, the apertures of the convex lens L2 and the corresponding convex lens L1 are the same. In addition, the optical axes (not shown) of the convex lens L2 and the corresponding convex lens L1 are also matched. Furthermore, the convex lens L2 is installed at a position separated from the projection lens 22 by a projection distance a, and a corresponding element image (real image) is formed inside each convex lens L2. It is assumed that the arrangement interval of the element images matches the arrangement interval of the corresponding convex lenses L1 and L2, and the optical axes of the convex lenses L1 and L2 pass through the center of the corresponding element image.

  Hereinafter, with reference to FIGS. 1 to 3, a description will be given of conditions under which the convex lens L2 directs the optical path of incident light and emits the light only to the corresponding convex lens L1 of the first lens group 33. To do. FIG. 2 is a schematic diagram schematically showing an optical path of light incident on the corresponding convex lenses L1 and L2, and (a) schematically shows an optical path when light from a pixel at the center of the element image is incident. FIG. 6B is a schematic diagram schematically showing an optical path when light from pixels other than the center of the element image is incident. FIG. 3 is a schematic diagram schematically showing a group of light rays that enter and exit the corresponding convex lenses L1 and L2 of the stereoscopic image display apparatus according to the first embodiment of the present invention.

First, when attention is paid to one pixel of a certain element image among a plurality of element images displayed on the display means 21, light (chief ray) emitted from this pixel and passing through the center of the projection lens 22 is The light is refracted by a convex lens 31 provided at a focal distance f _C away from the projection lens 22 to become light parallel to the optical axis A. Further, a light ray group emitted from this pixel and passed through the projection lens 22 is refracted by the convex lens 31, travels around a principal ray parallel to the optical axis A, and converges at one point inside the convex lens L2. Thereafter, the principal ray incident on the convex lens L2 is refracted by the convex lens L2, and passes through the center of the convex lens L1 provided at a focal distance f _{A of} the convex lens L1. Further, the light ray group converged on one point of the convex lens L2 is refracted by the convex lens L2, diffused around the principal ray passing through the center of the convex lens L1, and incident on the convex lens L1.

  Here, for example, as shown in FIG. 2 (a), light from the center point of the image of the element image formed inside a certain convex lens L2 is transmitted as it is and diffused around the optical axis A, The light enters the convex lens L1. As shown in FIG. 2B, light from a point other than the center of the image of the element image formed inside the convex lens L2 is refracted in accordance with the deviation from the center of the convex lens L2, and the convex lens L1. Diffusing around the principal ray passing through the center of the lens, and entering the convex lens L1.

Then, as shown in FIG. 3, when the following expression (1) is established at the angle θ at which the light rays emitted from each point of the element image formed inside the convex lens L2 are diffused, the convex lens L2 The outgoing light group enters only the corresponding convex lens L1 and enters the entire surface of the convex lens L1. Here, D _A is the aperture of the convex lenses L1 and L2.
θ = 2 arctan [D _A / (2f _A )] (1)

On the other hand, the convergence angle θ ′ of the light ray group incident on each point of the elemental image formed inside the convex lens L2 is expressed by the following equation (2). Here, _{D P} is the diameter of the exit pupil of the projection lens 22 (see FIG. 1) (diameter).
θ ′ = 2 arctan [D _P / (2a)] (2)

Focusing on one point of the image of the element image formed inside the convex lens L2, the angle θ ′ at which the incident light group converges and the angle θ at which the outgoing light group diffuses are considered to be substantially the same. Therefore, from the expressions (1) and (2), the convex lens L2 is designed so that θ ′ = θ, that is, the following expression (3) is satisfied, and the focal length f _A of the convex lens L1 is increased. , L2 are spaced apart in the optical axis direction, and the convex lens L2 can emit the incident light only to the corresponding convex lens L1.
D _A / f _A = D _P / a (3)

  Here, when using a conventional direct-view display or projecting an elemental image on the screen, the light diffused and emitted in various directions from the surface of the display or screen is reflected by the corresponding lens of the lens group and the corresponding lens. It enters into a plurality of other lenses. However, in the stereoscopic image display device 3, since all the light from each point of the elemental image formed inside the convex lens L2 is emitted to the corresponding convex lens L1, the light quantity can be secured and the false viewing zone Can be suppressed. Furthermore, since the light from the convex lens L2 can be incident on the entire surface of the convex lens L1 without excess or shortage without providing a diffusion plate, the resolution of the element image group does not deteriorate.

Here, in order to make all the light from the convex lens L2 enter the convex lens L1, it is only necessary to satisfy the following expression (4).
θ ≦ 2 arctan [D _A / (2f _A )] (4)
Then, from θ′≈θ, it is sufficient that D _p / a ≦ D _A / f _A is satisfied. Here, when D _p / a <D _A / f _A , a region where light does not enter is generated at the peripheral edge of the convex lens L1, and a non-light-emitting portion is generated at the peripheral edge of the convex lens L1, but is connected to the inside of the convex lens L2. It is the same as the case where Formula (3) is satisfied in that the light from the imaged elemental image does not enter other than the corresponding convex lens L1, for example, the convex lens L1 adjacent to the corresponding convex lens L1.

  Returning to FIG. 1, the description will be continued. The first lens group 33 includes a plurality of convex lenses L1, L1,... Arranged in an array on the same plane orthogonal to the optical axis A of the convex lens 31. It should be noted that the second lens group 32 and the first lens group 33 are placed so that the centers of the second lens group 32 and the first lens group 33 are on the optical axis A of the convex lens 31.

The convex lens (first element optical lens system) L1 collects light from each point of the image of the element image incident from the corresponding convex lens L2 or makes it parallel light. Here, the possible and the focal length f _B of the focal length f _A and lens L2 convex lens L1 are equal, parallel convex lens L1 is, the light from each of the image of the incident element image from a corresponding lens L2 point The case of using light will be described. However, the focal length f _A of the convex lens L1 may be smaller than the distance between the convex lens L1 and the convex lens L2, and the light may converge around the principal ray at the observation position.

  Here, focusing on one point of the elemental image inside the convex lens L2, as shown in FIGS. 2A and 2B, the chief ray of the light incident on the convex lens L1 goes straight as it is, and the convex lens L1. The ray group incident on the beam is emitted as parallel light having the same inclination as the principal ray. This inclination is determined according to the amount of deviation from the center of the point of interest in the convex lens L2.

  In this way, from each convex lens L1, the light from the corresponding element image is emitted as parallel light with an inclination corresponding to the amount of deviation from the center in the convex lens L2, and a viewing area of a certain angle is obtained. Form. The entire stereoscopic image display system 1 forms a viewing area as a common area of the viewing areas of all the convex lenses L1 as shown in FIG. FIG. 4 is a schematic diagram schematically showing the viewing zone of the stereoscopic image display system.

  The second lens group 32 may be shielded from light by applying a black paint to a certain region (for example, 10% outside the aperture) at the boundary where each convex lens L2 contacts. By doing in this way, the fall of the contrast of the reproduced stereo image (not shown) can be prevented.

Further, the focal distance f _C of the convex lens 31 may be set to a value close to the projection distance a of the projector 2, and the convex lens 31 and the second lens group 32 may be installed adjacent to each other. By installing in this way, the size of the stereoscopic image display device 3 can be reduced. However, when the size of the stereoscopic image display device 3 is not limited, the convex lens 31 and the second lens group 32 are provided. It is good also as installing separately.

[Operation of stereoscopic image display system (first embodiment)]
Next, with reference to FIG. 1, the operation | movement which the three-dimensional image display system 1 in this invention displays a three-dimensional image is demonstrated.

  First, the element image group is displayed on the display means 21 of the projector 2. Then, the light from the display unit 21 enters the projection lens 22. This light is projected by the projection lens 22, and the stereoscopic image display device 3 converges the projected light by the convex lens 31. Then, an image of each element image is formed inside the corresponding convex lens L2.

  Further, the light from the elemental image formed inside each convex lens L2 is directed to the optical path by the convex lens L2, and is incident only on the corresponding convex lens L1 of the first lens group 33. The light from the elemental image inside the convex lens L2 is emitted from the convex lens L1 as parallel light having an inclination corresponding to the amount of deviation from the center of the convex lens L2. Through the above operation, the stereoscopic image display system 1 can display a stereoscopic image indicated by the element image group.

[Configuration of stereoscopic image display system (second embodiment)]
Next, the configuration of a stereoscopic image display system 1A including the stereoscopic image display device 3A according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic diagram schematically showing a configuration of a stereoscopic image display system including the stereoscopic image display device according to the second embodiment of the present invention. Here, the optical path of light from the pixel at the center of a certain element image among the plurality of element images displayed on the display unit 21 is schematically illustrated. As shown in FIG. 5, the stereoscopic image display system 1 </ b> A projects a group of element images and displays a stereoscopic image.

  The stereoscopic image display system 1 </ b> A includes a stereoscopic image display device 3 </ b> A instead of the stereoscopic image display device 3. Since the projector 2 in the stereoscopic image display system 1A is the same as that shown in FIG. 1, the same reference numerals are given and the description thereof is omitted.

  The three-dimensional image display device 3 </ b> A displays a three-dimensional image from the light of the element image group projected from the projector 2. Here, the stereoscopic image display device 3 </ b> A includes a convex lens 31 </ b> A instead of the convex lens 31, and a first lens group 33 </ b> A instead of the first lens group 33. Since the second lens group 32 in the stereoscopic image display device 3A is the same as that shown in FIG. 1, the same reference numerals are given and description thereof is omitted.

The convex lens (condensing optical system) 31A condenses the light incident from the projector 2. The convex lens 31A is provided on the same optical axis A as the projection lens 22, and all of the light projected from the projection lens 22 enters the convex lens 31A. Here, the distance between the projection lens 22 and the convex lens 31A is larger than the focal length f _{C of the} convex lens 31A. And regarding this convex lens 31A, the position of the projection lens 22 and the position where the viewing zone is formed are conjugate positions. In other words, the positional relationship is such that the image of the projection lens 22 is formed at the viewing zone position.

The first lens group 33A includes a plurality of convex lenses (first element optical lens systems) L1A, L1A,... Arranged in an array on the same plane orthogonal to the optical axis A of the convex lens 31A. Here, the arrangement interval P1 of the convex lenses L1A of the first lens group 33A is set smaller than the arrangement interval P2 of the convex lenses L2 of the second lens group 32, and the following equation (5) is established. Note that f _A is the focal length of the convex lens L1, and coincides with the distance in the optical axis direction between the convex lens L1A and the convex lens L2. V is the distance in the optical axis direction from the convex lens L1A to the viewing zone.
P2 = P1 (1 + f _A / V) (5)

  The second lens group 32 and the first lens group 33A are placed on the optical axis A of the convex lens 31A so that the centers of the second lens group 32 and the first lens group 33A correspond to one convex lens L2. The convex lens L2 corresponding to the convex lens L1A is in a direction perpendicular to the optical axis A with respect to the convex lens L1A as the convex lens L1A is located away from the optical axis A in the direction orthogonal to the optical axis A. It is installed at a further distance.

Then, the projection lens 22 and the convex lens 31A are set apart from each other by a distance larger than the focal length f _{C of the} convex lens 31A, and the arrangement interval P1 of the convex lenses L1A of the first lens group 33A is set to the second lens group 32. By setting the convex lenses L1A and L2 on the principal ray of the light from the pixel at the center of the corresponding element image, by setting it smaller than the arrangement interval P2 of the convex lenses L2, each pair of the corresponding convex lens L1A and convex lens L2 The formed viewing zone is inclined with respect to the optical axis A as compared with the case where the arrangement interval P1 and the arrangement interval P2 are equal. Therefore, the viewing area as a common area of all the convex lenses L1A and L2 is widened.

  By adopting such a stereoscopic image display device 3A, a wide viewing zone can be secured, and since the diffuser plate is not used, the resolution does not deteriorate, and the convex lens L1A is designed so as to satisfy the above expression (4). Thus, the stereoscopic image display system 1A in which a false viewing zone does not occur can be obtained.

[Configuration of stereoscopic image display system (third embodiment)]
Next, with reference to FIG. 6, the structure of the three-dimensional image display system 1B provided with the three-dimensional image display apparatus 3B which is 3rd embodiment of this invention is demonstrated. FIG. 6 is a schematic diagram schematically showing a configuration of a stereoscopic image display system including the stereoscopic image display device according to the third embodiment of the present invention. Here, the optical path of light from the pixel at the center of a certain element image among the plurality of element images displayed on the display unit 21 is schematically illustrated. As shown in FIG. 6, the stereoscopic image display system 1 </ b> B projects a group of element images and displays a stereoscopic image.

  The stereoscopic image display system 1 </ b> B includes a stereoscopic image display device 3 </ b> B instead of the stereoscopic image display device 3. Since the projector 2 in the stereoscopic image display system 1B is the same as that shown in FIG. 1, the same reference numerals are given and the description thereof is omitted.

  The three-dimensional image display device 3 </ b> B displays a three-dimensional image from the light of the element image group projected from the projector 2. Here, the stereoscopic image display device 3 </ b> B includes a convex lens 31 </ b> B instead of the convex lens 31. The second lens group 32 and the first lens group 33 in the stereoscopic image display device 3B are the same as those shown in FIG.

The convex lens (condensing optical system) 31B condenses the light incident from the second lens group 32. The convex lens 31B is provided on the same optical axis A as the projection lens 22, and all of the light projected from the projection lens 22 and passed through the second lens group 32 enters the convex lens 31B. Here, the distance between the projection lens 22 and the convex lens 31B is larger than the focal length f _{C of} the convex lens 31B, and the convex lens 31B is installed between the second lens group 32 and the first lens group 33. The

  Here, the arrangement interval of the convex lenses L1 of the first lens group 33 is equal to the arrangement interval of the convex lenses L2 of the second lens group 32, and the image of the element image group projected by the projection lens 22 is the second The lens group 32 is formed. And it installs so that the center of the 2nd lens group 32 and the 1st lens group 33 may come on the optical axis A of the convex lens 31B, and each convex lens L1 respond | corresponds to one convex lens L2.

If the focal length of the convex lens 31B is f _C , the position of the projection lens 22 and the position of the viewing zone are in a conjugate relationship, and the following equation (6) is established.
1 / f _C = 1 / (a + c) + 1 / (f _A + V−c) (6)

  The center of the image of each element image coincides with the center of the convex lens L2, and the light passing through the center of the projection lens 22 from the center of each element image on the display means 21 passes through the center of the convex lens L2 and is projected by the convex lens 31B. Refract and change direction from optical axis A. Then, by allowing the light to pass through the center of the convex lens L1 and then reach the center of the viewing zone, an observer (not shown) can pass the second lens group 32 through the first lens group 33. The image of the group of element images formed inside can be seen.

  Then, the light passing through the second lens group 32 is condensed by the convex lens 31B, so that the light from each convex lens L2 changes its direction from the optical axis A and is refracted. Therefore, each light is formed by the convex lens L1. The viewing zone is inclined with respect to the optical axis A as compared with the stereoscopic image display device 3 shown in FIG. Therefore, the viewing zone as a common region of the viewing zones of all the convex lenses L1 is widened.

From the positional relationship among the projection lens 22, the convex lens 31B, the second lens group 32, and the first lens group 33, the following expression (7) is established.
(A + c) :( V + f _A −c) = c: (f _A −c) (7)
Then, the following equation (8) is obtained from the equation (7).
c = a · f _A / (a + V) (8)

The lens L1 and lens L2 are fixed at intervals f _A, by spaced a distance c which satisfies the equation (8) of the second lens group 32 is placed a convex lens 31B, a convex lens L1, The first lens group 33 and the second lens group 32 having the same shape, in which the arrangement interval of L1,... And the arrangement interval of the convex lenses L2, L2,.

  By adopting such a stereoscopic image display device 3B, a wide viewing zone can be secured, and since the diffuser plate is not used, the resolution does not deteriorate, and the convex lens L1 is designed so as to satisfy the above expression (4). Thus, the stereoscopic image display system 1B in which a false viewing zone does not occur can be obtained.

[Configuration of stereoscopic image display system (fourth embodiment)]
Next, with reference to FIG.7 and FIG.8, the structure of the stereoscopic image display system 1C provided with the stereoscopic image display apparatus 3C which is the 4th Embodiment of this invention is demonstrated. FIG. 7 is a schematic diagram schematically showing a configuration of a stereoscopic image display system including the stereoscopic image display device according to the fourth embodiment of the present invention. FIG. 8 is a schematic diagram schematically showing light incident on the convex lens 31C and one convex lens L1. In FIG. 7, light is emitted from the pixel at the center of each element image and passes through the center of the projection lens 22 with a dotted line, and is emitted from a pixel near the boundary of each element image, and passes through the center of the projection lens 22. The light path is indicated by a solid line. Although the case where the six convex lenses L1 are vertically arranged in the first lens group 33 is shown here, the number of the convex lenses L1 is not limited to this. As shown in FIG. 7, the stereoscopic image display system 1 </ b> C projects a group of element images and displays a stereoscopic image.

  The stereoscopic image display system 1 </ b> C includes a stereoscopic image display device 3 </ b> C instead of the stereoscopic image display device 3. Since the projector 2 in the three-dimensional image display system 1C is the same as that shown in FIG. 1, the same reference numerals are given and description thereof is omitted.

  The stereoscopic image display device 3 </ b> C displays a stereoscopic image from the light of the element image group projected from the projector 2. Here, the stereoscopic image display device 3 </ b> C does not include the second lens group 32 but includes a convex lens 31 </ b> C instead of the convex lens 31. Since the first lens group 33 in the stereoscopic image display device 3C is the same as that shown in FIG. 1, the same reference numerals are given and description thereof is omitted.

The convex lens (condensing optical system) 31C condenses the light incident from the projection lens 22. The convex lens 31C is provided on the same optical axis (not shown) as the projection lens 22, and all of the light projected from the projection lens 22 enters the convex lens 31C. Here, the distance between the projection lens 22 and the convex lens 31C is equal to the focal length f _C of the convex lens 31C, and here, the convex lens 31C is installed in front of the first lens group 33 on the optical path. It was.

Here, the projection distance a of the projection lens 22 is equal to the focal length f _C of the convex lens 31C, and the image of the element image group projected by the projection lens 22 is formed inside the convex lens 31C. The center of the convex lens 31C and the first lens group 33 is placed on the optical axis of the projection lens 22, and each of the elemental images corresponds to one convex lens L1.

  When attention is paid to the light ray group passing through the center of the projection lens 22, this light ray group is refracted by the convex lens 31C and output in parallel with the optical axis. Then, this light ray group enters the first lens group 33 and becomes light rays having various angles at the back focal position by the condensing action of each convex lens L1, thereby forming a viewing zone.

  Here, referring to FIG. 8 (refer to FIG. 7 as appropriate), an image of one element image and the convex lens L1 corresponding to the image of the element image will be described. As shown in FIG. 8, each pixel of the elemental image in the convex lens 31C is formed by imaging incident light in an angle range corresponding to the aperture of the projection lens 22. On the output side of the convex lens 31C, this pixel is formed. All of the principal rays of the ray group are parallel to the optical axis, and a ray group having substantially the same angular range as the incident light is emitted around the principal ray. Therefore, although a part of the light in the peripheral part of the element image does not enter the corresponding convex lens L1, the stereoscopic image display device 3C can be configured by the convex lens 31C and one lens group (first lens group 33). The resolution is not deteriorated because no diffusion plate is used.

Incidentally, the distance b between the image and the lens L1 of the element image, approximately equal to the focal length f _A of the convex lens L1, lens L1 focuses the light from each point element image to the observer's side, or, Has the effect of parallel light. In order to limit the occurrence of false viewing zones to some extent, it is desirable to satisfy D _A / b ≦ D _p / a. Furthermore, the convex lens 31C may be installed on the projector 2 side of the convex lens L1 or on the observer (not shown) side.

[Configuration of stereoscopic image display system (fifth embodiment)]
Next, a configuration of a stereoscopic image display system 1D including a stereoscopic image display device 3D according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram schematically showing a configuration of a stereoscopic image display system including the stereoscopic image display device according to the fifth embodiment of the present invention. In FIG. 9, light is emitted from the pixel at the center of each element image and passes through the center of the projection lens 22 with a dotted line, and is emitted from a pixel near the boundary of each element image, and passes through the center of the projection lens 22. The light path is indicated by a solid line. In addition, here, the case where the six convex lenses L1D are vertically arranged in the first lens group 33D is shown, but the number of the convex lenses L1D is not limited to this. As shown in FIG. 9, the stereoscopic image display system 1D projects a group of element images and displays a stereoscopic image.

  The stereoscopic image display system 1D includes a stereoscopic image display device 3D instead of the stereoscopic image display device 3. Since the projector 2 in the stereoscopic image display system 1D is the same as that shown in FIG. 1, the same reference numerals are given and the description thereof is omitted.

  The stereoscopic image display device 3 </ b> D displays a stereoscopic image from the light of the elemental image group projected from the projector 2. Here, the stereoscopic image display device 3 </ b> D does not include the second lens group 32, and includes a convex lens 31 </ b> D instead of the convex lens 31 and a first lens group 33 </ b> D instead of the first lens group 33.

The convex lens (condensing optical system) 31D condenses the light incident from the projection lens 22. The convex lens 31D is provided on the same optical axis (not shown) as the projection lens 22, and all of the light projected from the projection lens 22 enters the convex lens 31D. Here, the distance between the projection lens 22 and the convex lens 31D is greater than the focal length f _C of the convex lens 31D, here, a projection distance a of the projection lens 22, the distance between the projection lens 22 and the convex lens 31D is equal to that with did. And the image of the element image group projected by the projection lens 22 is formed inside the convex lens 31D.

  Further, the convex lens 31D is installed in front of the first lens group 33D on the optical path. And regarding this convex lens 31D, the position of the projection lens 22 and the position where the viewing zone is formed are conjugate positions. In other words, the positional relationship is such that the image of the projection lens 22 is formed at the viewing zone position.

The first lens group 33D includes a plurality of convex lenses (first element optical lens systems) L1D, L1D,... Arranged in an array on the same plane orthogonal to the optical axis (not shown) of the convex lens 31D. Composed. The center of the convex lens 31D and the first lens group 33D is placed on the optical axis of the projection lens 22, and each element image formed inside the convex lens 31D corresponds to one convex lens L1D. ing. Here, the arrangement interval P1 of the convex lenses L1D of the first lens group 33D is set smaller than the arrangement interval P2 of the image of each element image, and the following equation (9) is established. Note that b is the distance between the convex lens 31D and the first lens group 33D. V is the distance in the optical axis direction from the convex lens L1D to the viewing zone.
P2 = P1 (1 + b / v) (9)

  Then, the image of the element image group and the center of the first lens group 33D are placed on the optical axis of the convex lens 31D, and the convex lens L1D is located at a position away from the optical axis in the direction orthogonal to the optical axis. The more the element image corresponding to the convex lens L1D is formed at a position further away from the convex lens L1D in the direction perpendicular to the optical axis.

Then, a projection lens 22 and the convex lens 31D with installed off by the focal length f _C is greater than the distance between the convex lens 31D, the arrangement interval P1 of the convex lens L1D of the first lens group 33D, the image of each element image By setting the convex lens L1D on the principal ray of light from the pixel at the center of the corresponding element image by setting it smaller than the arrangement interval P2, the viewing zone formed by each corresponding convex lens L1D is arranged at the arrangement interval P1. Compared with the case where the arrangement interval P2 is equal, the optical axis is inclined. Therefore, the viewing zone as a common region of the viewing zones of all the convex lenses L1D is widened.

  A wide viewing zone can be secured by using such a stereoscopic image display device 3D. In addition, the stereoscopic image display device 3D can be configured by the convex lens 31D and one lens group (first lens group 33D), and the resolution is not deteriorated because the diffusion plate is not used.

Incidentally, the distance b between the image and the convex lens L1D element image substantially equal to the focal length f _A of the convex lens L1D, convex lens L1D condenses light from each point element image to the observer's side, or, Has the effect of parallel light. In order to limit the occurrence of false viewing zones to some extent, it is desirable to satisfy D _A / b ≦ D _p / a. Furthermore, the convex lens 31D may be installed on the projector 2 side or the observer (not shown) side of the convex lens L1D.

  The first lens group 33, 33A, 33D and the second lens group 32 described here are arranged in a two-dimensional direction by using convex lenses L1 (L1A, L1D), L2 having a condensing function in the horizontal direction and the vertical direction. However, it is also possible to use a first lens group and a second lens group (not shown) in which lenses (not shown) having a light collecting effect in one direction are arranged in one direction. For example, a first lens group and a second lens group (not shown) made of a lenticular lens sheet in which lenses (not shown) having a condensing function in the horizontal direction are arranged in the horizontal direction may be used. At this time, a vertical diffusion plate (not shown) having a diffusing action in the vertical direction is disposed at the image formation position of the element image group. As this vertical diffusion plate, a holographic diffuser (not shown) which is beam-shaped so as to have diffusion characteristics only in the vertical direction, or a lenticular lens sheet having a refractive action in the vertical direction can be used. Note that when a vertical diffusion plate having a diffusing action only in the vertical direction is installed, the horizontal characteristics that cause a three-dimensional effect are not affected, and resolution is not reduced.

  Furthermore, the condensing optical system, the first element optical lens system, and the second element optical lens system described in the claims are each composed of a convex lens 31, a convex lens L2, and a convex lens L1 (L1A, L1D). However, for example, it may be composed of a lens such as an optical fiber lens, or may be configured by combining a plurality of lenses.

It is the schematic diagram which showed typically the structure of the three-dimensional image display system provided with the three-dimensional image display apparatus which is 1st embodiment of this invention. The schematic diagram which showed typically the optical path of the light which injects into the corresponding convex lenses L1 and L2 of the three-dimensional image display apparatus which is 1st embodiment of this invention, (a) is from the pixel in the center of an element image. FIG. 5B is a schematic diagram schematically illustrating an optical path when light from pixels other than the center of the element image is incident. FIG. It is the schematic diagram which showed typically the light ray group which injects and radiate | emits to corresponding convex lens L1, L2 of the three-dimensional image display apparatus which is 1st embodiment of this invention. It is a schematic diagram which shows typically the visual field of a three-dimensional image display system provided with the three-dimensional image display apparatus which is 1st embodiment of this invention. It is the schematic diagram which showed typically the structure of the three-dimensional image display system provided with the three-dimensional image display apparatus which is 2nd embodiment of this invention. It is the schematic diagram which showed typically the structure of the three-dimensional image display system provided with the three-dimensional image display apparatus which is 3rd embodiment of this invention. It is the schematic diagram which showed typically the structure of the three-dimensional image display system provided with the three-dimensional image display apparatus which is the 4th embodiment of this invention. It is the schematic diagram which showed typically the light which injects into the convex lens 31C of the three-dimensional image display apparatus which is the 4th embodiment of this invention, and one convex lens L1. It is the schematic diagram which showed typically the structure of the three-dimensional image display system provided with the three-dimensional image display apparatus which is 5th embodiment of this invention. An explanatory diagram for explaining a conventional IP system, (a) is a schematic diagram schematically showing a configuration of an apparatus that captures an IP image by the conventional IP system, and (b) is a stereoscopic image by the conventional IP system. It is a schematic diagram which shows typically the structure of the apparatus which displays this. It is a schematic diagram which shows typically the example of a structure of a rear projection type video apparatus and a screen. Explanatory drawing for demonstrating the relationship between the element image in a conventional IP type display apparatus, a lens, and a viewing zone, (a) is a schematic diagram which shows typically the viewing zone determined by arrangement | positioning of an element image and a lens. (B) is a schematic diagram which shows typically the example of a false visual field.

Explanation of symbols

2 Projector (Projector)
3, 3A, 3B, 3C, 3D stereoscopic image display device 31, 31A, 31B, 31C, 31D Convex lens (condensing optical system)
32 2nd lens group L2 Convex lens (2nd element optical lens system)
33, 33A, 33D First lens group L1, L1A, L1D Convex lens (first element optical lens system)

Claims (4)

A display means for displaying an element image group composed of a plurality of element images imaged by an integral photography system imaging device; and a projection lens for projecting light incident from the display means ; A stereoscopic image display device that displays a stereoscopic image by receiving light from a projection device that projects and forms an image of the element image group on the same plane,
A condensing optical system for condensing the light from the projection device or making it into parallel light;
A plurality of first element optical lens systems that receive light from each image of the element image and collect light from each point of the image or convert the light into parallel light include the first element. An optical lens system and a first lens group arranged in an array on the same plane orthogonal to the optical axis of the condensing optical system,
Ri Der distance is more than the focal length of the focusing optical system and the focusing optical system and the projection lens,
The aperture of the first element optical lens system is D _A , the distance between the condensing optical system and the first element optical lens system is b, the aperture of the projection lens is D _P , the projection lens and the _A stereoscopic image display device satisfying a relationship of D _A / b ≦ D _P / a , where a is the distance to the condensing optical system . A display means for displaying an element image group composed of a plurality of element images imaged by an integral photography system imaging device; and a projection lens for projecting light incident from the display means ; A stereoscopic image display device that displays a stereoscopic image by receiving light from a projection device that projects and forms an image of the element image group on the same plane,
A condensing optical system for condensing the light from the projection device or making it into parallel light;
A plurality of first element optical lens systems that receive light from each image of the element image and collect light from each point of the image or convert the light into parallel light include the first element. A first lens group arranged in an array on the same plane orthogonal to the optical axis of the optical lens system and the optical axis of the condensing optical system;
A plurality of second element optical lens systems corresponding to each first element optical lens system and emitting light incident from the image of each element image only to the corresponding first element optical lens system. , Arranged in an array on the same plane perpendicular to the optical axis of the second element optical lens system and the optical axis of the condensing optical system and on which the image of the element image group is formed. Two lens groups;
With
Ri Der distance is more than the focal length of the focusing optical system and the focusing optical system and the projection lens,
The aperture of the projection lens is D _P , the distance between the projection lens and the second element optical lens system is a, and the apertures of the first element optical lens system and the second element optical lens system are D _A stereoscopic image display device satisfying a relationship of D _P / a ≦ D _A / f _A where _{A is} the focal length of the condensing optical system is f _A. The arrangement interval of the first element optical lens system in the first lens group and the arrangement interval of the second element optical lens system in the second lens group are the same,
The condensing optical system is provided between the first lens group and the second lens group;
The stereoscopic image display device according to claim 2, wherein a distance between the condensing optical system and the projection lens is larger than a focal length of the condensing optical system. An arrangement interval of the first element optical lens systems in the first lens group is narrower than an arrangement interval of the second element optical lens systems in the second lens group;
The second lens group is provided between the first lens group and the condensing optical system;
The stereoscopic image display device according to claim 2, wherein a distance between the condensing optical system and the projection lens is larger than a focal length of the condensing optical system.

Images