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:
Apr. 03, 2007
Filed:
Oct. 06, 2003
Junichi Iwai, Kanagawa, JP;
Hideki Yamamoto, Saitama, JP;
Junichi Iwai, Kanagawa, JP;
Hideki Yamamoto, Saitama, JP;
Sony Corporation, Tokyo, JP;
Abstract
Provided are a projector capable of correcting a polarization state properly and improving image quality, a retardation plate being used in a projector or the like and being capable of correcting a polarization state properly, and a method of placing a retardation plate. A quarter-wave plate () is placed between a reflective spatial light modulator () and a PBS (). The quarter-wave plate () includes a combination of a first retardation plate () and a second retardation plate () each producing a different phase difference. The phase differences produced by two retardation plates (), () are set to be suitable amounts of phase difference according to a position state, so in spite of the fact that the quarter-wave plate () including the combination of two retardation plates, the quarter-wave plate () can correct the polarization state properly with performance equal to or higher than that in the case where the quarter-wave plate includes a single plate.