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:
Oct. 14, 1986
Filed:
Jun. 12, 1984
Applicant:
Inventors:
William H Gross, Sunnyvale, CA (US);
Toyojiro Naokawa, Tsurugashimamachi, JP;
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 46 ; 369124 ; 369 45 ;
Abstract
A matrix circuit is disclosed having four inputs for coupling to either the four elements in a four-quadrant photodetector in a one-beam optical disc system or to the six elements in a hex photodetector in a three-beam optical disc system. A fifth input is provided with a logic input determined by which system is being implemented. Three outputs are provided, one each for signal, tracking error and focus error. The circuit will accommodate both systems to produce the required outputs with a minimum of redundant parts.