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. 12, 2003
Filed:
Dec. 30, 1998
Yuichi Maekawa, Tokyo, JP;
Mitburri Electric Co., LTD, Tokyo, JP;
Abstract
An optical disc drive equipped with a TLN signal generating apparatus is disclosed. The TLN signal generating apparatus includes a TLN signal generating circuit for generating a TLN signal (track loss signal) based on signals obtained from an optical pick-up; a digitizing circuit for digitizing the TLN signal by comparing it with a reference level; and a correction circuit for correcting the TLN signal so that it is accurately digitized by the digitizing circuit irrespective of an offset component which is a direct current component contained in the TLN signal. The correction circuit is comprised of an offset component detecting circuit for detecting a level of the offset component contained in the TLN signal; and a signal control circuit for controlling, responsive to the level of the offset component detected by the offset component detecting circuit, a level of the TLN signal generated by the TLN signal generating circuit so that the level of the TLN signal will become a level which does not receive any influence from the level of the direct component. The correction circuit can also be comprised of a signal correcting circuit which amplifies an alternating current component contained in the TLN signal without eliminating a directed current component contained in the TLN signal.