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:
Jul. 27, 2004
Filed:
Mar. 28, 2002
Daisuke Imafuku, Fujisawa, JP;
Naoyuki Ogura, Machida, JP;
Kazunari Nakagawa, Yokohama, JP;
Koji Hirata, Yokohama, JP;
Hidehiro Ikeda, Yokohama, JP;
Shuji Kato, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a projection lens, there are arranged in order from a screen side, a first lens group including a meniscus lens having a convex lens surface in a central portion toward a screen with refracting power, a second lens group including a lens having a convex lens surface in a central portion toward a video generating source, a third lens group including a lens having convex lens surfaces in both sides with positive refracting power, a fourth lens group including a lens having a convex lens surface in a central portion toward the video generating source with positive refracting power, and a fifth lens group including a lens having a concave lens surface toward the screen with negative refracting power. An entrance pupil is arranged between incident and emitting surfaces of a power lens.