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:
Nov. 12, 1991
Filed:
Dec. 14, 1989
Noriyoshi Takeya, Tokorozawa, JP;
Hidehiro Ishii, Tokorozawa, JP;
Chiharu Miura, Tokorozawa, JP;
Tatsuya Fukuda, Tokorozawa, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A servo system for a disc player having a pickup for reading information recorded on an information recording disc, includes an A/D converter for converting an error signal produced on the basis of signals output from the pickup into a digital signal, and performs driving and control of the pick up according to the signal level of the error signal having been processed digitally. The servo system further comprises a filter circuit permitting low frequency components of the error signal to pass therethrough and supplying the low frequency components to the A/D converter, detection circuit detecting noise components having levels higher than a predetermined level, contained in the error signal, and a circuit generating a control signal for a predetermined period after an instant of detection of the noise components by the detection circuit. The filter circuit has a first transmission characteristic with a cut-off frequency below one half of a sampling frequency of the A/D converter when the control signal is absent, and a second transmission characteristic with another cut-off frequency lower than the cut-off frequency when the control signal is present.