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:
Aug. 13, 2002
Filed:
Jun. 07, 1995
David L. Schell, Colorado Springs, CO (US);
David E. Lewis, Black Forest, CO (US);
Discovision Associates, Irvine, CA (US);
Abstract
An optical disc system for storing information on a medium includes a light source, a focusing mechanism, and a tracking mechanism wherein the mechanisms are controlled by a feedback loop and the focusing mechanism focuses light emitted by the light source onto the medium to effect writing of information thereon. The system is provided with an electronic circuit for generating a servo error signal that is communicated in the feedback loop for effecting corrections of the focusing mechanism and the tracking mechanism. The system is further provided with a driver for energizing the light source, a bias coil disposed proximate to the medium, a bias coil driver switchably connected to the bias coil for supplying an electric current thereto, a current monitoring circuit connected to the bias coil driver having an output responsive to the electric current, and a controller connected to the output of the current monitoring circuit and to the driver. The controller thereby enables the driver when the output of the current monitoring circuit exceeds a predetermined magnitude so that information processed through the focusing mechanism is written onto the medium when the electric current flowing in the bias coil exceeds a threshold.