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:
Jun. 01, 1993
Filed:
Jul. 26, 1990
Applicant:
Inventor:
Bryan Clark, Sunnyvale, CA (US);
Assignee:
Tandy Corporation, Ft. Worth, TX (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369100 ; 369111 ;
Abstract
An apparatus and method for erasing data from optical media in dual beam systems. The erase spot is focused to have a diameter equal to three times the track pitch of the medium. The larger erase spot eases spot alignment requirements since even beam misalignments of half a track width still supply enough energy to the medium to erase the data bump. The larger erase spot heats a larger area more gradually than a single track width erase beam and thereby also enables a more complete erasure of the medium.