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. 06, 1996
Filed:
May. 18, 1994
Satoshi Kawasaki, Tokyo, JP;
NEC Corportion, Tokyo, JP;
Abstract
Reproduced signals from detectors 1a to 1c installed in an optical head are level-adjusted by amplifiers 2a to 2c. Output signals of the amplifiers 2a and 2b are delayed by respective delay circuits 6a and 6b. An output signal of the delay circuit 6b and an output signal of the amplifier 2c are subtracted from an output signal of the delay circuit 6a by an adder 4. A reproduced signal from which cross-talk resulting from the adjacent track has been removed is obtained from the adder 4. The delay amounts of the delay circuits 2a and 2b are set according to delay control signals 8a and 8b. The delay amounts are set when accessing to a fixed pattern recording area disposed on a predetermined position of the optical disk. A control circuit 5 measures a time difference between the output signal of the detector 1b and the output signal of the detector 1c to output a delay control signal 8a. The control circuit 5 measures a time difference between the output signal of the detector 1a and the output signal of the detector 1c to generate a delay control signal 8a.