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:
Aug. 29, 1989
Filed:
Apr. 26, 1988
Shigeru Sasada, Kyoto, JP;
Shinichi Nagata, Kyoto, JP;
Makoto Hirosawa, Kyoto, JP;
Yoshihiro Kishida, Kyoto, JP;
Abstract
An optical system, useful for a flying-spot scanning apparatus includes a laser tube, an acousto-optical modulator, a deflecting mirror directing the laser beam in a first direction, and an objective lens having the characteristic of h=f.multidot.sin .theta., where h is the distance on an object between the optical axis and the point upon which the laser beam impinges, f is the focal length of the objective lens and .theta. is the angle formed by the beam entering the objective lens with respect to the optical axis. The objective lens includes a first optical unit having the negative focal length and a second optical unit having a positive focal length. The third-order distortion coefficient of the objective lens is approximately '1'. Straight and parallel scanning loci can be effected on a recording medium, as the recording medium is fed in a second direction.