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. 12, 2005
Filed:
Dec. 05, 2003
Eiki Matsuo, Suwa, JP;
Eiki Matsuo, Suwa, JP;
NEC Viewtechnology, Ltd., Tokyo-To, JP;
Abstract
A luminous flux, from one conjugate surface (A), having an opening angle of at least 10° sequentially passes through a first optical system () having a luminous flux convergent action in the vicinity of its reference axis and a second optical system () having a luminous flux divergent action in the vicinity of its reference axis, and converges on another conjugate surface (B). A specific condition is given to the converging distance of each converging point at a luminous flux section including a principal ray according to the passing position of the luminous flux through the first optical system () to thereby implement an oblique-incident optical system having a half angle of at least 60° and a comparatively simple structure irrespective of a type of an optical element used.