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:
Jun. 03, 1997
Filed:
Aug. 28, 1995
Seiji Kawata, Tokyo, JP;
Yuzo Ono, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In an image forming apparatus, a mechanism for scanning the inner periphery of a hollow cylindrical drum has stationary optics including two semiconductor lasers fixed in place. The two lasers have their p-n junction planes positioned perpendicular to each other, i.e., one of them is horizontal while the other is vertical. Lights from the lasers are combined on the same axis by a polarizing beam splitter. A quarter-wave plate has its optical axis inclined .+-.45 degrees relative to the direction of polarization. The combined wave from the beam splitter is transformed by the quarter-wave plate to light having a clockwise and a counterclockwise polarization overlapping each other on the same axis. In the rotary optics, another quarter-wave plate converts the incident light to a composite wave of linear polarizations perpendicular to each other. This composite wave is incident to a splitting element as a P wave and an S wave or as ordinary rays and extraordinary rays. As a result, the P wave and S wave or the ordinary rays and extraordinary rays are spatially separated into two beams for scanning a film in parallel.