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:
Oct. 26, 1993
Filed:
Nov. 20, 1991
Junko Shingaki, Atsugi, JP;
Hideaki Mitsutake, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical modulating device comprises a polarizer, an analyzer and liquid crystals positioned between the polarizer and the analyzer. The device controls the birefringence of the liquid crystals by applying an electric field to the liquid crystals so as to change the polarization of light of the device. The device further comprises a rotatable halfwave plate which is positioned between the liquid crystals and the analyzer or between the liquid crystals and the polarizer in such a manner that the optical axis of the halfwave plate will be rotated around the optical axis of light coming into the optical modulating device. The device varies the rotational angle of the halfwave plate in accordance with the temperature of the liquid crystals or the environment thereof.