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:
Apr. 13, 1993
Filed:
Nov. 30, 1990
Tsuneo Yanagida, Hino, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An apparatus for detecting unused sectors in an optical disk or opto-magnetic disk including an envelope detection circuit for detecting an envelope of a read signal to derive an envelope detection signal when data is recorded in a data area of sector. Sector mark and address marks recorded in an identification area are detected to derive sector mark detection signal is generated and address mark detection signals, and an interpolated mark signal corresponding to a synchronizing signal recorded in the data area in accordance with the sector mark detection signal and address mark detection signals. When the envelope detection signal is not produced, the generation of the interpolated mark signal is inhibited. Thus when the synchronizing signal is not detected in the data area and the generation of the interpolated signal is inhibited, the relevant sector is detected as the unused sector.