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:
Sep. 03, 2002
Filed:
Jan. 17, 2002
Yoshinori Hayashi, Kawasaki, JP;
Ricoh Technology Research, Inc., Kanagawa, JP;
Abstract
An optical scanning apparatus for optically scanning a surface to be scanned at a constant velocity includes a light source for emitting a light flux, a first optical lens system for coupling the light flux emitted by the light source to a subsequent optical lens system, a second optical lens system for forming the light flux received from the first optical lens system into a line image extending in a direction corresponding to a main scanning direction for the surface to be scanned, an optical deflector for deflecting the light flux formed as the line image via a deflecting reflective plane thereof, which is located near where the line image is formed, and a third optical lens system for condensing the deflected light flux as an optical beam spot on the surface to be scanned. The second optical lens system includes at least one plastic lens and one glass lens, and a surface of the at least one plastic lens of the second optical lens system is configured such that a change in a curvature of field in directions corresponding to the main scanning direction and the sub scanning direction, respectively, which is caused by a change in the plastic lens of the third optical lens system due to changes in an operating temperature, is corrected and compensated.