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:
Aug. 14, 1990
Filed:
Apr. 29, 1988
Koji Hirata, Yokohama, JP;
Kyohei Fukuda, Fujisawa, JP;
Hiroki Yoshikawa, Hiratsuka, JP;
Shigeru Mori, Chigasaki, JP;
Masayuki Muranaka, Yokohama, JP;
Isao Yoshizaki, Yokohama, JP;
Shigeru Inaoka, Yokohama, JP;
Hiroshi Jitsukata, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a projection system wherein an optical system comprising a first lens for correcting a spherical aberration dependent on the aperture length, a second lens for enlargement and a third lens for correcting a field curvature, projects an image reproduced on a CRT having a curved phosphor surface, onto a screen, the third lens is spaced from the CRT so that the region of the phosphor surface which again totally reflects a light which has been totally reflected by a screen-side surface of the third lens is limited to the edge portion of an effective region of the phosphor surface.