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, 2004
Filed:
Oct. 30, 2002
Ryuji Suzuki, Saitama, JP;
Canon Kabushiki Kaisha, Ohta-Ku, JP;
Abstract
A color separation/combination optical system according to the present invention comprises of a polarization beam splitter which performs at least one of separation of illumination light from a light source into light components for a plurality of colors and combination of light components for modulated by a plurality of image display elements, a plurality of temperature varying units which are disposed in opposition to or in contact with different surfaces of the polarization beam splitter and change the temperature of the polarization beam splitter, a temperature sensor which detects the temperature of the polarization beam splitter. The system also includes a control circuit controls the temperature varying units based on the temperature detected by the temperature sensor to prevent the action of birefringence caused by internal stress in an optical glass material constituting the polarization beam splitter from hindering a desired action of polarized light separation.