Method of and apparatus for recording/reading information, circuit for recording/reading signal
AssigneeFujitsu Limited
InventorsMasaru Sawada, Toshihiko Morita, Takao Sugawara
Life of this patent
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Abstract
An information recording/reading apparatus employs a preamble to reproduce a clock used when recording information in a recording medium and reads the information out of the recording medium at a timing synchronized with a read signal. The preamble is split and recorded by replacing a middle portion of the preamble with data and a sync byte. While a first buffer is employed to delay signal data read out of the recording medium, a frequency offset detector detects a frequency offset using the split preamble.
Claims9
An information recording/reading apparatus that reads information from a recording medium at a timing synchronized with a read signal by reproducing a clock used when recording the information with timing reproduction data, comprising:
- a signal delay unit that delays signal data read from the recording medium for a predetermined time, the signal data having timing reproduction data that is split and recorded in the recording medium by setting a middle portion of the timing reproduction data as an area for recording the information;
- and
- a frequency offset detecting unit that detects, during the predetermined time, a frequency offset that is a frequency difference between a clock of the read signal and an operation clock of the information recording/reading apparatus using the timing reproduction data that is split and recorded in the recording medium;
- wherein the timing reproduction data is cyclic waveform data divided into a plurality of blocks,
- a phase of the timing reproduction data that is split and recorded in the recording medium is continuous, and
- the frequency offset detecting unit detects the frequency offset based on a difference between a phase difference of a cyclic waveform of a leading block from a reference waveform and a phase difference of a cyclic waveform of an ending block from the reference waveform.
An information recording/reading circuit that reads information from a recording medium at a timing synchronized with a read signal by reproducing a clock used when recording the information with timing reproduction data, comprising:
- a signal delay circuit that delays signal data read from the recording medium for a predetermined time, the signal data having the timing reproduction data that is split and recorded in the recording medium by setting a middle portion of the timing reproduction data as an area for recording the information;
- and
- a frequency offset detecting circuit that detects, during the predetermined time, a frequency offset that is a frequency difference between a clock of the read signal and an operation clock of the information recording/reading circuit using the timing reproduction data that is split and recorded in the recording medium;
- wherein the timing reproduction data is cyclic waveform data divided into a plurality of blocks,
- a phase of the timing reproduction data that is split and recorded in the recording medium is continuous;
- and
- the frequency offset detecting unit detects the frequency offset based on a difference between a phase difference of a cyclic waveform of a leading block from a reference waveform and a phase difference of a cyclic waveform of an ending block from the reference waveform.
An information recording/reading method to read information from a recording medium at a timing synchronized with a read signal by reproducing a clock used when recording the information with timing reproduction data, comprising:
- delaying signal data read from the recording medium for a predetermined time, the signal data having the timing reproduction data that is split and recorded in the recording medium by setting a middle portion of the timing reproduction data as an area for recording the information;
- and
- detecting, during the predetermined time, a frequency offset that is a frequency difference between a clock of the read signal and an operation clock of the information recording/reading apparatus using the timing reproduction data that is split and recorded in the recording medium;
- wherein the timing reproduction data is cyclic waveform data divided into a plurality of blocks,
- a phase of the timing reproduction data that is split and recorded in the recording medium is continuous;
- and
- the frequency offset detecting unit detects the frequency offset based on a difference between a phase difference of a cyclic waveform of a leading block from a reference waveform and a phase difference of a cyclic waveform of an ending block from the reference waveform.
Dependencies are inferred from the claim text.