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:
Sep. 17, 1991
Filed:
Dec. 11, 1989
Ian E Henderson, Tucson, AZ (US);
Morovat Tayefeh, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A magnetooptic disk has circumferentially-spaced-apart, radially-aligned embossed sector areas which indicate data storage tracks. The sector areas include embossed signals which indicate track-following information, and in a second area which trails the track-following information, track-seeking information is carried by the embossed signals. A magnetooptic coating covers the entire disk including the embossed sector areas. Readback clock synchronization signals are recorded over the track-seeking area to enable synchronizing a readback phase-locked loop such that more of the areas between sector areas can be used for recording data signals. During track seeking, the track seek controlling embossed signals are read using intensity demodulation, while in track following, during a readback, the clock signals recorded over the embossing are read for synchronizing the readback circuits. During recording, the synchronization signals are recorded over the embossed area dedicated to track seeking.