Record/playback track tracking servo
Optical information processor for compensating offset
Disc playback apparatus
Optical information processing apparatus
Reproducing device for frequency modulated signals Patent #: 4815061
ApplicationNo. 581175 filed on 09/05/1990
US Classes:369/47.35, For sampling, digital to analog or analog to digital converting369/44.31, Recording369/44.34Sampling servo system
ExaminersPrimary: McElheny, Donald Jr.
Attorney, Agent or Firm
Foreign Patent References
International ClassG11B 007/00
Foreign Application Priority Data1987-07-08 JP
AbstractA reference level adjusting circuit for a signal containing both DC and RF components, such as provided by a read head in an optical recording and reproduced device. In the reproduction mode, the read input signal is capacitively coupled through an amplifier to an A/D converter. A read input signal detected from an unrecorded area is held and, during the recording mode, is substituted for the presently read input signal.