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:
Mar. 20, 1979
Filed:
Oct. 25, 1977
Jerome Drexler, Los Altos Hills, CA (US);
Carl R Betz, Los Altos, CA (US);
Drexler Technology Corporation, Palo Alto, CA (US);
Abstract
An error checking method and apparatus for recording digital data in an optical recording medium. Digital data are written onto the medium by a modulated laser whose beam is detected by a first photodetector means which measures laser output directed toward the recording medium. A second photodetector means measures light scattering from the medium, while a third photodetector detects and measures light transmitted through the recording layer of the medium serving to confirm recording of the data. Amounts of transmitted light or scattered light from the medium are correlated to the laser output and to expected values of light for detecting errors in recording immediately after the time of recording. Reversal processing of the recording medium eliminates a large fraction of potential errors.