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:
Jul. 29, 1997
Filed:
Mar. 09, 1994
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
Abstract
An optical scanning system includes a first lens for receiving a light beam from a light source and allowing the light beam to pass therethrough, and a polygon mirror having at least one reflection surface for deflecting the light beam from the first lens by reflecting the light beam on the reflection surface thereof. A second lens is provided for receiving the light beam from the polygon mirror and focusing the light beam on a first plane to be scanned. The second lens has a first surface facing toward the polygon mirror and a second surface facing toward the first plane. The first surface is of a toric shape defined by rotating, about an axis of symmetry lying in a second plane which contains an optical axis of the second lens and is parallel to a first direction in which scanning takes place, a curve lying in the second plane and having a center of curvature on the optical axis, while the second surface is of a toric aspherical shape defined by a surface-generating profile equation in which terms have respective orders equal to or greater than a fourth order with respect to the first direction. The first and second surfaces of the second lens have radii of curvature R1 and R4, respectively, in the first direction as measured from the polygon mirror along the optical axis. The radii of curvature R1 and R4 have a relationship given by .vertline.R4.vertline.<.vertline.R1.vertline..