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:
Mar. 13, 2006
Filed:
Aug. 04, 2003
Method and apparatus for optical recording and reproducing with tracking servo reducing track offset
Toshimitsu Kaku, Sagamihara, JP;
Kazuo Shigematsu, Saitama-ken, JP;
Hisataka Sugiyama, Tokyo, JP;
Takeshi Maeda, Kokubunji, JP;
Masahiro Takasago, Odawara, JP;
Toshimitsu Kaku, Sagamihara, JP;
Kazuo Shigematsu, Saitama-ken, JP;
Hisataka Sugiyama, Tokyo, JP;
Takeshi Maeda, Kokubunji, JP;
Masahiro Takasago, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is an optical recording and reproducing apparatus comprising a light source directing a light spot toward a recording medium, a detection system detecting light reflected from the recording medium to derive an electrical signal from the reflected light, an information processing circuit modulating the intensity of the light spot according to writing pulses to record information on the recording medium and using the electrical signal to reproduce information from the recording medium, and a tracking servo circuit carrying out tracking servo operation on the basis of the electrical signal and including an extracting circuit connected to a source of extracting pulses having a pulse width at least equal to the writing pulse width so that writing pulse parts contained in the electrical signal are extracted during recording information, whereby a track offset occurring during information recording can be minimized, and the stability of the tracking servo system can be improved.