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AssigneeHitachi, Ltd.
InventorsToshimitsu Kaku, Kazuo Shigematsu, Hisataka Sugiyama, Takeshi Maeda, Masahiro Takasago
Estimating the term…
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.
An optical recording and reproducing apparatus comprising:
An optical disk apparatus comprising:
A method of optical recording and reproduction including the steps of directing a light spot toward a recording medium, modulating the intensity of said light spot according to writing pulses to record information on said recording medium, and detecting light reflected from said recording medium to reproduce information from said recording medium, said method comprising the step of carrying out a tracking servo operation on the basis of an electrical signal detected from said reflected light and including applying extracting pulses having a pulse width at least equal to greater than that of said writing pulses so that time-wise portions of said electrical signal corresponding to the writing pulses during recording of information are not utilized for the tracking servo operation when the extracting pulses are present.
Dependencies are inferred from the claim text.