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:
Dec. 01, 1992
Filed:
Jul. 23, 1990
Sony Corporation, Tokyo, JP;
Abstract
An optical recording and/or reproducing apparatus comprising a light beam generator, a photodetector, an optical path forming device for causing a light beam from the light beam generator to impinge upon an optical disc and for guiding the light beam emanating from the optical disc to the photodector, and a signal generating circuit block operative to obtain based on a detection output obtained from the photodetector a first signal representing a tracking condition of the light beam in relation to a record track portion on the optical disc and a second signal different in phase by substantially ninety degrees from the first signal and to produce a tracking error signal which satisfies the following equation: