JP3576630B2 - Projection type stereoscopic image display device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a stereoscopic image display device used in stereoscopic television broadcasting and the like, and enables a viewer to view a stereoscopic image in a natural state without requiring special glasses such as polarized glasses. And a projection type stereoscopic image display device.
[0002]
[Prior art]
Conventionally, as a stereoscopic image display device used in stereoscopic television broadcasting, a stereoscopic image viewing device using special glasses such as polarized glasses and shutter glasses, and a stereoscopic image without glasses using a lenticular screen or the like. There is known an apparatus for observing images.
[0003]
[Problems to be solved by the invention]
However, the above-described conventional stereoscopic image display device has the following problems.
[0004]
First, in a stereoscopic image display device that uses a pair of special glasses such as polarized glasses and shutter glasses to view a stereoscopic image, a viewer wears special glasses such as polarized glasses and shutter glasses when viewing the stereoscopic image. Is a prerequisite, there is a problem that a stereoscopic image cannot be viewed in a natural state.
[0005]
Also, in a stereoscopic image display device that uses a lenticular screen or the like to view a stereoscopic image without eyeglasses, a lenticular screen formed by arranging a large number of long and slender, semi-cylindrical lenses in parallel or a large number of slits formed in one plate. The parallax barrier and the like created by the viewer allow the viewer to view the left and right images separately for the left and right eyes, so that the range (viewing range) of stereoscopic vision is extremely narrow. If the viewer moves, the positions of the left and right eyes move, and there is a problem that the left-eye image may be reversed to the right eye and the right-eye image may be reversed to the left eye, and a stereoscopic image may not be formed. Was.
[0006]
In view of the above circumstances, the present invention does not bother using special glasses such as polarized glasses or shutter glasses, and always moves the left-eye image to the right eye and the right-eye image to the right even if the viewer moves. To provide a projection type stereoscopic image display device capable of displaying a correct stereoscopic image by directing it to the eyes, and also allowing a plurality of viewers to view a large screen stereoscopic image in a wide viewing area. The purpose is.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a projection-type stereoscopic image display device according to the present invention provides an image display for displaying an image observed by combining left-eye image light and right-eye image light having polarization angles different from each other by 90 °. Means, light collecting means for causing the left-eye image light and the right-eye image light respectively emitted from the image display means to enter the left and right eyes of the viewer, respectively, and the left and right eyes of the viewer A half-face detecting means for detecting the position of the eye, a liquid crystal element disposed between the image display means and the light condensing means and having a plurality of light transmitting areas partitioned in a matrix, and having a unidirectional polarization characteristic An optical path selecting unit having a polarizing plate, and defining an optical path of left-eye image light and right-eye image light emitted from the image display unit and incident on the left eye and the right eye of the viewer via the condensing unit, respectively. And the left of the viewer detected by the half-face detecting means. And a transmission area control means for generating a control signal for controlling the light path selection means based on the position information of the right eye, wherein the light path selection means is configured such that each light transmission area of the liquid crystal element is transmitted from the transmission area control means. The optical path of the image light for the left eye and the image light for the right eye is defined by changing the polarization angle of the passing light in accordance with the control signal.
[0008]
Further, in the projection type stereoscopic image display device of the present invention, the optical path selection means is constituted by a liquid crystal element which enables selection of a transmission area from the plurality of areas partitioned in a matrix by the transmission area control means. It is characterized by having.
[0009]
Further, in the projection type stereoscopic image display device of the present invention, the condensing unit may be configured such that the light-condensing unit is configured to emit the left-eye and right-eye image light and the left-eye and right-eye image light with respect to the screen surface. Are configured by a double fly eye lens screen device which is a plane object.
[0010]
Further, in the projection type stereoscopic image display device of the present invention, the light condensing means may be arranged such that the light-emitting points of the left-eye and right-eye image light and the left-eye and right-eye It is characterized by being constituted by a convex lens, a holographic lens, a diffraction grating lens, a selfoc lens, or a Fresnel lens, each of which has a point symmetry with the focal point of the image light for the eye.
[0011]
Further, in the projection type stereoscopic image display device of the present invention, the light condensing means is configured by a cat's eye lens screen device or a triple mirror screen device in which the optical path of incident light and the optical path of outgoing light are the same for the means. In addition, the display characteristics of the device are of a reflective display type.
[0012]
Further, in the projection type stereoscopic image display device according to the present invention, the light condensing means is constituted by a concave mirror, and the display characteristics of the concave mirror are of a reflective display type.
[0013]
Further, the projection type stereoscopic image display device of the present invention is characterized in that the diffusion plate is configured as a transmission type or a reflection type.
[0014]
Further, in the projection type stereoscopic image display device of the present invention, the diffusing plate is further provided with a convex lens, a Fresnel lens or an array lens, or the convex lens, the Fresnel lens or the array lens is processed into a diffusing plate. An object is used as the diffusion plate.
[0015]
【Example】
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing the basic configuration of the projection type stereoscopic image display device of the present invention.
In FIG. 1, reference numeral 10 denotes an image display unit, 20 denotes an optical path selecting unit and a polarization angle changing unit, 30 denotes a condensing unit, and 40 denotes a half face detecting unit and a transmission area control unit. As shown in FIG. 1, the synchronization signal generation circuit 50 includes the left and right image projectors 1 and 2 in the image display means 10 and the television camera 7 and the half This is for supplying a synchronization signal to the face measurement circuit 8.
[0016]
In the above, the image display means 10 includes image projectors 1 and 2 that receive left-eye and right-eye image signals and generate left-eye image light and right-eye image light, respectively, that form a stereoscopic image. I have. Here, for example, a 90-degree polarizing plate (not shown) is disposed in the vicinity of or in the optical path of the image display window of the image projector 1 so that the right and left image light beams have different polarization angles. The left and right image lights having different polarization angles are projected onto the diffusion plate 3 in the image display means 10 in a state where the two image lights are aligned.
[0017]
Each light emitted from the diffusion plate 3 (left image light and right image light indicated by a broken line and a solid line, respectively) is incident on an optical path selection unit and a polarization angle displacement unit 20. A liquid crystal element (hereinafter referred to as a liquid crystal element) which is arranged at a predetermined distance from the diffusion plate 3 of the image display device 10 and which can arbitrarily and desirably control the light transmitting portion from among a plurality of regions partitioned in a matrix by an external control signal. , An LCD), a polarizing plate 5 having a unidirectional polarization characteristic, and image light transmitted through the LCD 4 and the polarizing plate 5 on a Fresnel lens as a condensing unit 30 described later. And a convex lens 6 for focusing an image. Among these, the light transmission control element 4 has a function of receiving a control signal from a half-face detection unit and a transmission region control unit 40, which will be described later, and changing the polarization angle of light passing through the region specified by the control signal. Have.
[0018]
The transmitted light corresponds to the A region and the B region corresponding to the left-eye image light and the right-eye image light, respectively. In the illustrated example, the image display means 10 converts the left-eye image light into the right-eye image light. Since the polarization angle is advanced by +90 degrees as compared to the light, the polarization angle displacement means (the function of the light transmission control element 4) imparts a polarization angle displacement of -90 degrees to the transmitted light in the region A. As a result, the polarization angles of the left-eye image light and the right-eye image light are both 0 degrees.
[0019]
The half-face detection unit and the transmission region control unit 40 follow the A region and the B region, which are the light transmission regions of the left-eye and right-eye image light, of the light transmission control element 4 described above, respectively, following the movement of the human eye. This is a means for setting automatically. In particular, half-face detection means for detecting left and right half-faces including the vicinity of the viewer's eyes include, for example, Shigeru Omori, Jun Suzuki, Kunimasa Kataoka, Sadayuki Sakuma, Tomohiko Hattori `` Backlight split type stereo display system '', 3D Image Conference '94 Lecture Paper Collection 5-5, 3D Image Conference '94 Executive Committee, July 7-8, 1994, among which, in particular, "3.2 Backlight Optical System" ( The collection of these papers, pages 221 to 222) describes a method for independently obtaining left and right face half-face images. In addition, since it is also described in detail in Japanese Patent Application No. 6-213460 “Stereoscopic display device” of one of the present applicants, the description of the operation principle and the like is omitted here. The half-face position measurement circuit is constituted by an electronic circuit (not shown) including a level adjustment circuit, a subtraction circuit, a binarization circuit, and the like. ing.
[0020]
As described above, in the optical path selection unit and the polarization angle displacement unit 20, the left-eye image light and the right-eye image light transmitted through the A region and the B region of the light transmission control element 4 such as an LCD have the same polarization angle. (In the case shown, both are 0 degrees.) If the polarization angle of the polarizing plate 5 is set to 0 degrees, the optical paths of the left and right image lights are separated for the above-described reason, and the Fresnel lens as the light condensing means 30 is used. It is sharpened upward and further separated and incident on the left and right eyes of the observer, so that stereoscopic vision is possible.
[0021]
Further, in the projection type stereoscopic image display apparatus of the present invention, the light condensing means 30 (see FIG. 1) for separating and entering each of the left and right image lights into the left and right eyes of the viewer is limited to the above-described Fresnel lens. For example, the emission points of the left-eye and right-eye image light and the converging points of the left-eye and right-eye image light around a screen surface whose characteristics are shown in a conceptual diagram in FIG. May be constituted by a double fly eye lens screen device, each of which is a plane object. However, in this case, since the incident light and the transmitted light have a plane symmetric characteristic about the lens screen, the image light for the left eye and the image light for the right eye are reversed, unlike the case of FIG. .
[0022]
Further, as another example of the light condensing means, the emission points of the image light for the left eye and the right eye and the light condensing of the image light for the left eye and the right eye with respect to the center point of the lens constituting the light condensing means. A cat's eye lens screen composed of a convex lens, a holographic lens, a diffraction grating lens, and a selfoc lens, each of which has a point symmetry with respect to a point, or a condensing means in which an optical path of incident light and an optical path of output light are the same. The display device may be constituted by a device or a triple mirror screen device, or may be constituted by a concave mirror, and the display characteristics of the device may be a reflection display type.
[0023]
Further, the optical path selection means used in the display device of the present invention is not limited to the above-mentioned LCD, but may be used as long as the polarization angle can be individually controlled for each area divided into a plurality of sections on a plane. Can be.
[0024]
Further, in the display device of the present invention, the diffusion plate 3 in the image display device 10 may be changed from the above-mentioned transmission type to the reflection type, and the positional relationship between the diffusion plate 3 and the image projectors 1 and 2 may be exchanged. Furthermore, in order to increase the light-collecting efficiency to the optical path selecting means, a convex lens, a Fresnel lens, an array lens, or the like may be additionally arranged on the diffusion plate 3, and a lens obtained by processing the lens or the like into a diffusion plate may be used. Good.
[0025]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the projection type stereoscopic image display apparatus of this invention, each image light is isolate | separated by controlling each optical path of the image light for left eyes and the image light for right eyes following the movement of a human eye (both right and left eyes). So that it is incident on the left and right eyes of the viewer, so that the viewer does not have to worry about wearing special glasses such as polarized glasses or shutter glasses as in the past, You can see it.
[0026]
Further, according to the display device of the present invention, the display position of the image light for the left and right eyes does not reverse as in the conventional method using a lenticular screen or a parallax barrier. At the same time, a stereoscopic image on a large screen can be viewed in a wide viewing area.
[Brief description of the drawings]
FIG. 1 is a diagram showing the basic configuration of a projection type stereoscopic image display device according to the present invention.
FIG. 2 is a conceptual diagram of characteristics in a case where a light condensing unit used in the display device of the present invention is configured by a double fly eye lens screen device.
[Explanation of symbols]
1, 2 image projector 3 diffuser 4 light transmission control element (LCD)
5 Polarizing Plate 6 Convex Lens 7 Television Camera 8 Half Face Position Measurement Circuit 10 Image Display Means 20 Optical Path Selection Means and Polarization Angle Displacement Means 30 Condensing Means 40 Half Face Detection Means and Transmission Area Control Means 50 Synchronization Signal Generation Circuit

Claims (7)

Image display means (10) for displaying an image observed by combining left-eye image light and right-eye image light having polarization angles different from each other by 90 °;
Focusing means (30) for causing the left-eye image light and the right-eye image light respectively emitted from the image display means (10) to enter the left and right eyes of the viewer ,
A half-face detecting means (40) for detecting a position of a left eye and a right eye of the viewer ,
A liquid crystal element (4) which is disposed between the image display means (10) and the light condensing means (30) and has a plurality of light transmitting regions partitioned in a matrix, and a polarizing plate having one-way polarization characteristics ( 5) optical path selecting means for defining the optical paths of the left-eye image light and the right-eye image light which are emitted from the image display means and enter the left and right eyes of the viewer via the condensing means, respectively. (20) ,
Transmission area control means (40) for generating a control signal for controlling the optical path selection means based on positional information of the left and right eyes of the observer detected by the half face detection means (40) ,
The light path selecting means (20) changes the polarization angle of light passing through each light transmission area of the liquid crystal element according to a control signal from the transmission area control means, so that image light for the left eye and image light for the right eye are changed. A projection type stereoscopic image display device, wherein an optical path of image light is defined . 2. The projection-type stereoscopic image display device according to claim 1, wherein the light condensing unit collects the emission points of the left-eye and right-eye image lights and the left-eye and right-eye image lights around a screen surface. A projection-type stereoscopic image display device comprising a double fly eye lens screen device whose light spots are respectively plane-symmetric. 3. The projection stereoscopic image display device according to claim 1, wherein the light condensing unit is configured to output a left-eye image light and a right-eye image light with respect to a center point of a lens included in the unit. A projection type stereoscopic image display device comprising a convex lens, a holographic lens, a diffraction grating lens, a selfoc lens, or a Fresnel lens, each of which has a point symmetrical with a condensing point. 3. The projection type stereoscopic image display device according to claim 1, wherein the light condensing means is configured by a cat's eye lens screen device or a triple mirror screen device in which an optical path of incident light and an optical path of output light are the same. A projection type stereoscopic image display device, wherein a display characteristic of the projection type stereoscopic image display device is a reflection display type. 3. The projection type stereoscopic image display device according to claim 1, wherein the condensing unit is configured by a concave mirror. 4. The projection type stereoscopic image display device according to any one of claims 1 to 5 , wherein the image display means has a diffusion plate, and the diffusion plate is configured to be a transmission type or a reflection type. Projection type stereoscopic image display device. In the projection type stereoscopic image display device according to any one of claims 1 to 6, the diffuser plate, further a convex lens, or have added disposed Fresnel lens or an array lens, or the lens, Fresnel lens Alternatively, a projection type stereoscopic image display device, wherein an arrayed lens processed into a diffusion plate is used as the diffusion plate.

Images