Stereoscopic video image display

• US 4,461,541 A
• Filed: 03/25/1982
• Issued: 07/24/1984
• Est. Priority Date: 03/25/1982
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Duthie, Joseph G. M.
• Primary Examiner(s): Henry, Jon W.
• Application Number:
  US06/362,015
• Time in Patent Office: 852 Days
• Field of Search: 350/132, 350/130, 350/162.12, 358/88, 358/89, 358/91, 358/92
• US Class Current: 359/465
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G02F 1/135 Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied G02F1/133348 takes precedence

Abstract

An image display system and method provides at least two separate and distinct images of a viewed scene for an observer. The images, taken from adjacent positions looking toward the target scene, are taken from relatively small, acute position angles with respect to the scene. These separate images are then encoded with different polarization in sequence for displaying on a television monitor. The images are prepared for viewing by an observer by focusing the monitored images onto a liquid crystal light valve. Collimated light from a coherent source addresses the light valve providing a coherent output therefrom with the encoded images thereon. These images are brought to a Fourier plane and polarized or filtered selectively to provide separately encoded images in alternate frames of polarization. An observer wearing separately polarized lens and viewing an output screen sees a stereoscopic view of the imaged scene.

Claims

1. A method of displaying encoded stereoscopic video images comprising the steps of:

displaying encoded film containing video images on a television monitor;

imaging the video images as an incoherent input onto a light valve;

addressing the light valve output to provide coherent output images;

polarizing the addressed light valve output;

transforming the polarized output by Fourier transformation to create in a plane, a pattern having different orders of diffraction light containing said images;

masking the plane with first and second masks disposed in a common plane to pass only selected of said diffraction light for sequentially passing alternate orthogonally polarized video images therethrough;

reimaging the images onto a screen for viewing; and

viewing of said reimaging image by an observer through polarized eyeglasses to produce a stereoscopic effect.

2. A method of displaying encoded stereoscopic video images as set forth in claim 1 and further comprising the steps of:

addressing the light valve output by directing a collimated read out light to a beamsplitter at the output of said light valve; and

directing said collimated read out light by said beamsplitter to the output of said light valve for combining with the output to provide said coherent images output.

3. Apparatus for displaying of encoded stereoscopic video images comprising:

a television monitor for imaging a plurality of images sequentially from a video input, said plurality of images being input video signals that are multiplexed so that adjacent television frames are images of a common source taken from different angles, a light valve having an input and an output, the input of said light valve being disposed for receiving said images from said monitor, a Fourier transform lens, a beam splitter between the output of said valve and said Fourier transform lends for directing coherent images from said valve to said lens, a polarization analyzer disposed between the beam splitter and the Fourier transform lens, a spatially coherent light source for directing collimated light to said beam splitter for addressing the output side of said light valve and thereby providing a coherent output of said plurality of images from said valve to said Fourier transform lens, and means for imaging said plurality of images for viewing, said means for imaging including first and second orthogonally polarized masks disposed in a plane adjacent the Fourier transform lens.

4. Apparatus for displaying of encoded stereoscopic video images comprising:

a television monitor for imaging a plurality of images sequentially from a video input, said plurality of images being input video signals that are multiplexed so that adjacent television frames are images of a common source taken from different angles, a light valve having an input and an output, the input of said light valve being disposed for receiving said images from said monitor, a Fourier transform lens, a beam splitter between the output of said valve and said Fourier transform lens for directing coherent images from said valve to said lens, a spatially coherent light source for directing collimated light to said beam splitter for addressing the output side of said light valve and thereby providing a coherent output of said plurality of images from said valve to said Fourier transform lens, means for imaging said plurality of images for viewing and wherein said means for imaging comprises a mask, an imaging lens and a screen disposed in coaxial order for receiving the coherent output of said Fourier transform lens, said mask being disposed at a predetermined plane adjacent the transform lens to polarize selected first and second images of the beam in directions orthogonal to each other, the imaging lens reimaging the input scenes in orthogonal polarization onto the screen for viewing.

5. Apparatus for displaying of encoded stereoscopic video images as set forth in claim 4 wherein said light valve is a liquid crystal light valve, and further comprising a lens between the monitor and the input of said light valve for transfering images from the monitor to the valve.

6. Apparatus for displaying of encoded stereoscopic video images as set forth in claim 6 and further comprising a linear polarizer disposed between said coherent light source and said beam splitter, and a polarization analyzer disposed between said beam splitter and said Fourier transform lens.