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. 08, 1991
Filed:
Jan. 02, 1990
Der-Chang Hsieh, Cupertino, CA (US);
Tandy Corporation, Fort Worth, TX (US);
Abstract
A system and method for erasing data on an optical storage disk of the type which is responsive to light of first selected characteristics to produce a detectable physical change in the disk and is further responsive to light of second selected characteristics to reverse the physical change. Erasure is effected by rotating the disk proximate a linear light source capable of projecting a curtain of light having said second selective characteristics onto the disk. Uniform erasure of the data may be obtained by modifying the light flux which is delivered to the disk as a function of distance from the center of the disk. In particular, by increasing the flux or flux density which strikes the disk proximate its periphery relative to that which strikes near the center, the unit dosage received by any portion of the disk may be equalized.