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:
Nov. 07, 1995
Filed:
Sep. 10, 1993
Sadao Nakai, Ibaraki-shi, Osaka 567, JP;
Masanobu Yamanaka, Minoo, JP;
Koji Ishikawa, Neyagawa, JP;
Tsuyoshi Sato, Tokyo, JP;
Kimiaki Yamamoto, Tokyo, JP;
Mikihiko Terashima, Tokyo, JP;
Abstract
The invention is directed to a focusing optical system for semiconductor lasers, which is regulated in terms of magnification power in both its directions normal to the optical axis, so that the back focus of sufficient magnitude can be made equal in both the directions and the magnitude of aberration can be regulated to achieve an improvement in focusing efficiency, and in which a light beam from a semiconductor laser having varying exit angles in the horizontal and vertical directions is focused on a spot having substantially equal diameters in the horizontal and vertical directions. This focusing optical system comprises first lens unit L1 including a rotation asymmetric lens having positive power in the direction defined by a large exit angle at which a laser beam emanates from the laser, a second lens unit L2 including at least one lens of negative power, and a third lens unit L3 that is a rotation asymmetric lens unit having positive power in the directions defined by both large and small exit angles.