Browse Prior Art Database

STEREO PROJECTOR FOR 3-D PRESENTATIONS

IP.com Disclosure Number: IPCOM000026592D
Original Publication Date: 1992-Dec-31
Included in the Prior Art Database: 2004-Apr-06
Document File: 2 page(s) / 131K

Publishing Venue

Xerox Disclosure Journal

Abstract

A stereo overhead projector for display of three dimensional (3-D) images is disclosed. Computer applications such as computer-aided design (CAD) manipulate image files representing 3-D space. Although holography enables hardcopy output of 3-D image files, presentation of holographic images poses more difficulty. Stereo slide shows, for example, use two orthogonally polarized slide projectors to present 3-D images. A air of slides are projected

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XEROX DISCLOSURE JOURNAL

STEREO PROJECTOR FOR 3-D PRESENTATIONS U.S. C1.040/411 John R. Andrews

Proposed Classification

Int. C1. G09f 19/08

A stereo overhead projector for display of three dimensional (3-D) images is disclosed. Computer applications such as computer-aided design (CAD) manipulate image files representing 3-D space. Although holography enables hardcopy output of 3-D image files, presentation of holographic images poses more difficulty. Stereo slide shows, for example, use two orthogonally polarized slide projectors to present 3-D images. A air of slides are projected

separated by polarized glasses worn by viewers. Each eye in effect views one of the polarized images. Stereographic movies presented using a twin projection system use a similar technique that requires precise alignment of the image pair for viewing each time the system is used. An alternative technique for showing 3-D images on a cathode ray tube (CRT) uses a polarization switching unit that covers the CRT screen and alternates polarization of the light of sequential frames between two orthogonal polarization states. The two images of the stereo pair are alternately displayed on the CRT, while polarized glasses are again used to separate the two polarized views for each eye.

onto a metallic non-depolaridng screen. The pair o P reflected images are then

Overhead projection devices consisting of an electronically addressed liquid crystal dot-matrix exist in 2-D. In such devices, a display is placed on a conventional overhead projector in place of a trans arency such as the Kodak Data Show @ which projects computer video in i! ormation onto projection screens. 2-D liquid crystal presentations require a computer for generating and storing graphics, a conventional overhead projector and a 2-D liquid crystal device that is positioned on top of the projector and connected to the computer.

The disclosed stereo projection system covers an entire projection area of a 2-D
dot-matrix liquid crystal display (LCD) with a polarization switching unit. The polarization switching unit switches in synchronization with the frames that are presented on t...