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. 01, 2005
Filed:
Jun. 23, 2003
Motonobu Kawabata, Kyoto, JP;
Masahiko Kokubo, Kyoto, JP;
Motonobu Kawabata, Kyoto, JP;
Masahiko Kokubo, Kyoto, JP;
Dainippon Screen Mfg. Co., Ltd., Kyoto, JP;
Abstract
An optical scanner according to the present invention comprises a collimator lens, a cylindrical lens, a light deflector, an f-θ lens and an anamorphic lens. The f-θ lens is constituted by three groups of five lenses, i.e., a first cemented lens formed by bonding a first lens and a second lens to each other, a second cemented lens formed by boding a third lens and a fourth lens to each other and a fifth lens having positive refracting power. The f-θ lens is formed to satisfy relational expressions L/f<0.100 and 0.04≦r1/r4≦0.31, where L represents the total length of the f-θ lens, f represents the focal distance of the f-θ lens, r1 represents the radius of curvature of an entrance-side refracting interface of the first lens and r4 represents the radius of curvature of an entrance-side refracting interface of the third lens. Thus, a compact optical scanner comprising an f-θ lens having a small total length L and high optical performance is provided also when increasing a focal length f as well as a scanning line length W.