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:
Jul. 16, 1996
Filed:
Mar. 01, 1995
Edward C Gage, Fairport, NY (US);
Steven C Dohmeier, Rochester, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
An apparatus and method for providing differential detection and source noise subtraction in data signals read from magneto-optic (MO), write-once (WO) or other types of optical storage media using an incident radiation beam. A source monitor signal is generated by detecting radiation from an optical source providing the radiation beam. An error detector generates an error signal corresponding to a difference between the source monitor signal and a reference signal. A power level of the radiation beam is adjusted in response to the error signal. A data signal generator is adapted to receive a return beam resulting from application of the radiation beam to the medium and to generate a WO data signal from the return beam. A signal combiner combines the data signal and the source monitor signal to provide a compensated WO data signal. An MO data signal may be generated using a separate AGC circuit to adjust the gain of each differential detection channel in accordance with low-frequency amplitude differences between the detected signals and a reference signal. The same reference signal may be used in both the source noise subtraction and the MO data signal generation.