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:
Sep. 23, 2003
Filed:
May. 13, 2002
Koji Hirata, Yokohama, JP;
Naoyuki Ogura, Ebina, JP;
Shigeru Mori, Chigasaki, JP;
Takahiro Yoshida, Miura, JP;
Kazunari Nakagawa, Ebina, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A projection lens system for enlarging and displaying on a screen an original image from an image generating source, includes a first lens having positive refractive power, a second aberration correction lens, and a third lens, positioned nearest the image generating source and having a concave lens surface thereof facing the screen. The third lens has a profile such that its refractive power at a marginal area adjacent a peripheral edge thereof is less than its refractive power at an area adjacent an optical axis of said projection lens system. The surface of the third lens facing the image generating source is in contact with a cooling liquid which cools the image generating source.