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. 22, 1994
Filed:
Dec. 24, 1992
Richard L Wilkinson, La Mirada, CA (US);
Stephen P Brown, Santa Ana, CA (US);
Shigang Li, Norwalk, CA (US);
Optical Disc Corporation, Santa Fe Springs, CA (US);
Abstract
Method and apparatus for improving the characteristics of the surface effects recorded on an optical disc, for use with an optical recording apparatus which includes a writing light beam source and an optical modulator for modulating the intensity of the writing beam of light above and below a threshold level of a moving recording medium in response to a modulator drive signal for recording information on the medium, the light beam being capable of forming a track of surface effects or indicia in the moving recording medium when the writing beam is above threshold and incapable of forming surface effects in the moving recording medium when the writing beam is below threshold. The method includes receiving a substantially rectangular waveform having leading and trailing edges, provided as a modulator drive signal to modulate the writing beam to a peak power above threshold and to a minimum power level below thresholds, respectively, and producing a shaped modulator drive signal by increasing the peak power of the writing beam responsive to the occurrence of the leading edges, by decreasing the time the shaped modulator drive signal is above threshold in order to maintain a prescribed duty cycle in the track of surface effects in the moving recording medium, and by producing symmetrical leading and trailing edges of the surface effects.