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:
Mar. 28, 2000
Filed:
Mar. 30, 1998
Atsushi Hatakeyama, Ibaraki, JP;
Shigekazu Yamagishi, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A light source for emitting a white light in one direction, color light separating means for separating the white light from the light source into three color lights of red light, blue light and green light, modulating means including liquid crystal light valves for modulating the polarized lights contained in the luminous fluxes from the color light separating means, and producing a video image, color light combining means for combining the modulated luminous fluxes after being modulated by the modulating means, and projection optical means for projecting the combined luminous flux obtained by the color light combining means on a screen. A polarizer is disposed at the light exit side of the modulating means. A dichroic filter having characteristics for selectively passing and selectively reflecting the color lights from the modulating means is disposed between the color light combining means and the modulating means positioned on an optical path of at least one color light of the three color lights of the red light, blue light and green light. The quarter-wave plate has a plurality of quarter-wave plates, a first quarter-wave plate of the plurality of quarter-wave plates is contacting with the dichroic filter, and a second quarter-wave plate of the plurality of quarter-wave plates contacts the dichroic filter, and is disposed between the dichroic filter and the color light combining means.