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:
Jan. 12, 1993
Filed:
Jan. 04, 1990
Ryuzo Tamayama, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical encoder for a disc apparatus having a head arm to record and reproduce a disc-shaped recording medium, a scale swung together with the head arm, a reticle and a light sensitive element disposed on one side of the scale, and a light emitting element disposed on the other side of the scale. The phases of slit patterns in the reticle and light receiving portions of the light sensitive element opposed thereto are each divided into halves, and the divided phases are distributed symmetrically on the opposite sides of the reticle center in the directions of swing motion of the scale. And the same distributed phases of the light receiving portions are individually connected to each other, thereby eliminating the phase deviation of the detection output that results from temperature fluctuation and so forth.