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. 28, 1988
Filed:
Dec. 24, 1985
Yuzo Ono, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A laser beam scanner that includes a laser source emitting light at a frequency (X.sub.2) and a rotatable hologram produced by interfering lasers at a frequency (X.sub.1) and located a distance (a) from the laser source and a scanned surface at a distance (b) from the hologram. The hologram satisfies the image forming relationship 1/F.sub.1 =1/f.sub.0 +1/f.sub.R where F.sub.1 is the focal distance of the hologram and f.sub.0 and f.sub.R are the respective distances of the hologram from the divergent and convergent points where the interfering lasers are located. The laser source is located in a position away from the optical axis of the hologram so as to enlarge the diffraction angle. However, in order to compensate for resulting astigmatism, the hologram is produced by selecting the positions of the two interfering lasers in order to satisfy the image formation relationship in a region distant from the hologram optical axis and not to satisfy the image formation relationship on the optical axis.