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:
Feb. 05, 1991
Filed:
Jan. 03, 1989
Takayuki Yoshioka, Tokyo, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A projection lens system including seven lens elements for use in a projection television which comprises, in order from the screen side, a first lens unit composed of a positive lens element, a second lens unit composed of an aspherical lens element made of plastic in a meniscus form having at least one aspherical surface, a third lens unit composed of a concave lens element, a fourth lens unit composed of a positive cemented lens having a convex surface on both sides, a fifth lens unit composed of a positive lens element made of plastic in meniscus form having at least one aspherical surface, and a sixth lens unit composed of a negative lens element which has a concave surface directed toward the screen, the sixth lens unit being made of a plastic lens in meniscus form having at least one aspherical surface.