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. 08, 2014
Filed:
Oct. 09, 2012
Toshiyuki Yanagisawa, Suwa, JP;
Toshiyuki Yanagisawa, Suwa, JP;
Nittoh Kogaku K.K., Suwa-Shi, Nagano, JP;
Abstract
A projector lens system is provided. The projector lens system comprising, in order from a screen side thereof: a first negative lens that is made of resin and is convex on the screen side; a first positive lens that is made of glass and is biconvex; a stop; a cemented lens that has negative refractive power and is composed, in order from the screen side, of a second negative lens that is made of glass and a second positive lens that is made of glass; and a third positive lens that is made of resin, wherein a refractive index nof the first negative lens, a refractive index nof the first positive lens, a refractive index nof the second positive lens, and a refractive index nof the third positive lens satisfy the following conditions: 1.45≦n≦1.60; 1.45≦n≦1.60; 0.16≦n−n≦0.31; 0.16≦n−n≦0.31; 0.95≦nn≦1.05; and 0.95≦nn≦1.05.