The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 17, 1993
Filed:
Jan. 23, 1991
Canon Kabushiki Kaisha, Ohta, JP;
Abstract
A projector capable of compactizing the structure and improving the efficiency of light utilization is disclosed. The projector has an illuminating system, a light modulation device and a projection optical system. A first and a second lights of mutually different colors are emitted from the illumination optical system. The light modulating device has a first light modulator for modulating the first light according to a first image signal and a second light modulator for modulating the second light according to a second image signal. Each of the first and second light modulators is provided with a grating, a liquid crystal filled in the grooves of the grating and a driver for driving the molecules of the liquid crystal. The driver is adapted to drive the molecules of the liquid crystal in such a manner that the liquid crystal and the grating have mutually substantially matching refractive indexes in a certain state but have mutually unmatched refractive indexes in another state, thereby generating or substantially erasing a diffraction grating by the grating and the liquid crystal. A first and a second images of mutually different colors are projected on a screen by the first and second lights from the first and second light modulators.