Method for recording and reproducing data on recording mediums
AssigneeRicoh Company, Ltd.
InventorMichiharu Abe
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Abstract
The present invention relates to a method of recording and reproducing data on a recording medium, wherein original data is recorded on a recording medium by converting it into a code having more than one "0" between bits "1" such as MFM code and RLL (1,7) code, and a timing of a zero-cross of a reproductive signal or a second order differential signal from the recording medium is detected to obtain a bit "1" and reproduce the original data. The method allows to avoid affect of interference between marks and to record and reproduce data at high recording density and with high reliability.
Claims10
A data recording/reproducing method comprising the steps of:
- converting an original data into a code in such a manner that more than one "0" is inserted continuously between a bit "1" and a bit "1" in a time series signal made by combination of binary bits "0" and "1";
- recording a mark string on a recording medium by inverting alternatively presence and absence of a recording mark, timing with an appearance of the bit "1" in a converted code to thereby record the data;
- scanning a recording mark string with a mark detecting means to obtain a reproductive signal corresponding to the mark string;
- detecting a timing of an inversion of the presence or the absence of the recorded mark in the obtained reproductive signal to obtain a converted code by comparing the amplitude of the reproductive signal with a first predetermined value and differentiating the reproductive signal to obtain a first order differential value;
- and
- obtaining the original data from the converted code to reproduce the original data,
- wherein when the converted code includes a pattern "01010", the presence of the pattern "01010" is detected by using the fact that an amplitude of the reproductive signal of the pattern "01010" is smaller than a first predetermined value, and a time where the first order differential value of the reproductive signal crosses a zero level is used as a position of the central "0" in the pattern "01010".
A data recording/reproducing method comprising the steps of:
- converting an original data into a code in such a manner that more than one "0" is inserted continuously between a bit "1" and a bit "1" in a time series signal made by combination of binary bits "0" and "1";
- recording a mark string on a recording medium by inverting alternatively presence and absence of a recording mark, timing with an appearance of the bit "1" in a converted code to thereby record the data;
- scanning a recording mark string with a mark detecting means to obtain a reproductive signal corresponding to the mark string;
- detecting a timing of an inversion of the presence or the absence of the recorded mark in the obtained reproductive signal to obtain a converted code by differentiating the reproductive signal to obtain a first and second order differential value and comparing the amplitude of the second order differential value with a predetermined value;
- and
- obtaining the original data from the converted code to reproduce the original data,
- wherein the time where the first order differential value of the reproductive signal crosses a zero level is used as a position of the central "0" in the pattern "01010" only when an amplitude of the second order differential value of the reproductive signal of the pattern "01010" is greater than the predetermined value.
Dependencies are inferred from the claim text.