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:
May. 07, 2013
Filed:
Apr. 11, 2012
Takahiko Matsuo, Suwa, JP;
Takahiko Matsuo, Suwa, JP;
Nittoh Kogaku K.K., Suwa-shi, Jagano, JP;
Abstract
A projection lens system has first, second and third lens groups. The first lens group with combined focal length fhas, in order from a screen side, a first negative meniscus lens, a second negative meniscus lens with focal length f, refractive index nand screen side surface radius of curvature R, and a negative biconcave lens with focal length f. A second lens group consists of a positive biconvex lens with a radius of curvature Rof a surface on a light modulator side of the positive biconvex lens. The system satisfies the following conditions: 1.0<|f/f|<4.0; 5.0<|f/f|<9.0; 1.75<n<2.0; and 0.1<|R/R|<0.8.