JPH01220997A - Stereoscopic television set - Google Patents

Abstract

PURPOSE:To attain stereoscopic vision regardless of the posture of a viewer by mounting a 1/4 wavelength plate and using a right rotatory and a left rotatory circularly polarized light so as to switch a picture signal for right and left eyes. CONSTITUTION:A stereoscopic visual difference video signal corresponding to right/left eyes is projected alternately in time division from a projector 1. Then the video signal is formed to be right rotatory or left rotatory circularly polarized light by a circularly polarized light changeover device 8. The device 8 consists of a polarizer 2, an optical phase conversion element 3 and a 1/4 wavelength plate 4 altogether and the changeover of the right rotatory and left rotatory circularly polarized light is applied in synchronism with the changeover of the right and left eye pictures of the video signal projected by the video device 1. Thus, the video image projected onto a reflection screen 9 passes either of the right and left eye spectacles of a viewer spectacle 10 depending on the rotating direction of the circularly polarized light and the viewer can observe the stereoscopic video image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stereoscopic video device, and particularly to playback of a stereoscopic video device that does not depend on the posture of a viewer.

[Conventional technology]

A conventional split-type three-dimensional image projection system using single binocular parallax is described in Japanese Patent Application Laid-Open No. 59-21191.

[Problem to be solved by the invention]

In the above conventional technology, image signals for the left eye and right eye are switched using linearly polarized light that is orthogonal to each other, and the viewer wears an analyzer with a component that directs light in front of the left and right eyes. For the left eye.

Since the image signal for the right eye is separated, if the viewer's posture changes and the angle of the analyzer for image signal separation changes accordingly, crosstalk will occur between the left eye image and the right eye image. , there was a problem that stereoscopic viewing became difficult.

An object of the present invention is to enable stereoscopic viewing regardless of the viewer's posture.

[Means to solve the problem]

The above object is achieved by making the image signal circularly polarized using a quarter-wave plate.

This makes it possible to view images that are not affected by changes in the relative angle between the analyzer worn by the viewer and the projection device. In this case, the image signals for the left eye and the right eye are separated by switching between left-handed and right-handed circularly polarized light, which is converted into linearly polarized light using a 174-wave plate on the viewer's side, and then passed through an analyzer. Obtain a three-dimensional image.

[Effect]

The operation of this device will be described with reference to Figure 1.

The projection device 1 alternately projects stereoscopic parallax video signals corresponding to the left eye and the right eye. When each video signal passes through the polarizer 2, it becomes linearly polarized light having a polarization component in the direction of the arrow in the figure. This video signal then passes through the optical phase conversion element 3. 3
When is in the initial state, the video signal passes through without changing the polarization state, and when the switching signal is applied, the polarization is switched by 90 degrees. The switching signal is synchronized with the projection device 1, and in the case of the configuration shown in the figure, no signal is applied when the image for the left eye is being projected, and the switching signal is not applied when the image corresponding to the right eye is being projected. A concrete example of the six-optical phase conversion element 3 in which the polarization direction is switched by 90@ when the light passes through the PLZT is an element using an electro-optic effect such as PLZT. 3, the video signal passes through a quarter-wave plate 4. When linearly polarized light is incident on a quarter-wave plate, if the angle θ between the linearly polarized plane of the incident light and the main cross section of the wavelength plane is 45'', the emitted light becomes circularly polarized. In some cases, the emitted light beam becomes circularly polarized light with opposite rotation.Therefore, the polarization direction of polarizer 2 is 1/4
The angle formed with the wave plate 4 is set to 45 degrees, and the polarization direction of the video signal incident from 2 to 3 is changed by the optical phase conversion element 3 to 9
By switching the polarization of the image projected onto the screen 5 to 0", the polarization of the image projected on the screen 5 can be switched between right-handed circularly polarized light and left-handed circularly polarized light. The viewer places the 1/4 wavelength plate 6 on the 45° angle, and - Analyzer 7 arranged at 45°
Put on the ornamental glasses consisting of a and 7b. The circularly polarized light that reaches 6 from the screen becomes linearly polarized light at 45° or -45° with respect to the main cross section of 6 depending on the rotation direction and is emitted from 6, so it can be separated by analyzers 7a and 7b, respectively. It is. As mentioned above, since the switching of the polarization direction in step 3 is synchronized with the switching of the left eye image signal and the right eye image signal to the projection device 1, an image with stereoscopic parallax is presented to the left and right eyes of the viewer. , you can get images with a three-dimensional effect. At this time, since the image on the screen is circularly polarized, viewer glasses that combine 6, 7a, and 7b,
There is no limit to the relative angle with the projection device system of 1, 2, 4.5, and therefore the viewer can take any posture when viewing stereoscopic images.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a reflection type projection device. Stereoscopic parallax video signals corresponding to left and right hibernation are alternately projected from the projection device 1 in one time division. The video signal is turned into clockwise or counterclockwise circularly polarized light by a circular polarization switching device 8. 8 is a summary of 2, 3.4 in FIG. Switch polarization. The image projected on the reflective screen 9 passes through either the right eye chain part or the left eyeglass part of the viewer's glasses 10 depending on the rotation direction of the circularly polarized light,
Viewers will be able to view 3D images. 10 is 41
6 and 7a in the figure.

This is a summary of 7b. According to this embodiment, it is possible to project stereoscopic images without being restricted by the viewer's posture, without making major changes to the equipment for normal non-stereoscopic image projection in theaters and the like.

FIG. 3 shows an embodiment in which the present invention is applied to a projection type television. The video signal of the image reproduced by the image reproduction device 11 is sent to a set of three projection tubes 12a, b, c corresponding to each red, green, and blue image signal.

A circular polarization switching device 13 is arranged in front of each projection tube,
Similarly to 8 in FIG. 2, the rotation direction of the circularly polarized light of the video signal is switched.

According to this embodiment, it is possible to obtain stereoscopic images from various image sources such as a VTR.

〔Effect of the invention〕

According to the present invention, it is possible to view a stereoscopic image regardless of the viewer's posture, thereby reducing restrictions on the installation location of the stereoscopic image device and preventing fatigue of the viewer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the principle of the present invention, and FIGS. 2 and 3 are block diagrams of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Projection device, 2... Polarizer, 3... Optical phase conversion element, 4, 6... 1/4 wavelength plate, 5... Screen, 7a. 7b...Analyzer. 2 Figures/I--1 image soldier lol Naokai 1 Figure I-t & 4 Zokyosha certain device-g, first move 3--1 Koiri order B1 tablet ≦ 1 number of approaching hit IL--V
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Claims (1)

[Claims] 1. When an element that performs optical phase modulation in synchronization with an external signal and a polarizer are installed in the image projection unit, a quarter-wave plate is attached to the left eye in a split-type 3D image projection device. , a stereoscopic television device characterized in that image signals for the right eye are switched using clockwise and counterclockwise circularly polarized light.