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:
Jun. 23, 1992
Filed:
Apr. 19, 1991
Applicant:
Inventors:
Mitsushige Kondo, Nagaokakyo, JP;
Shinsuke Shikama, Nagaokakyo, JP;
Eiichi Toide, Nagaokakyo, JP;
Hiroshi Kida, Nagaokakyo, JP;
Masahiro Usui, Nagaokakyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
353 99 ; 353 37 ; 353102 ; 359 49 ;
Abstract
In a projection display device having an illumination optical system which converts the light emitted from a point light source into a substantially parallel luminous flux, a light valve which modulates the light flux, and an optical projection system which projects images on the light valve onto a screen, the illumination optical system converts the light into a substantially parallel luminous flux having a cross section of substantially the same size and shape, e.g., rectangular shape, as the shape of the frame of the light valve.