Data recording method, data reproduction method, data recording device, data reproduction device and optical recording medium
AssigneeFujitsu Limited
InventorsKenichi Hamada, Akira Nanba, Masakazu Taguchi
Life of this patent
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Abstract
A data recording method for calculating a digital sum value (DSV) corresponding to a proportion of positive data and negative data included in predetermined data ranges, selecting a resync pattern to be inserted between the data ranges according to the DSV, and inserting the selected resync pattern between the data ranges, has a step of selecting a resync pattern that minimizes differences in DSV between the data ranges.
Claims8
A data reproduction method for calculating an amount of change in a DC component of a reproduction wave form, correcting an expected value in response to a moving average value of the amount of change in the DC component, and reproducing data in response to the corrected expected value, the method comprising the steps of:
- calculating a present amount of change in the DC component;
- calculating a moving average value of the present DC component change amount and a previous DC component change amount;
- calculating a moving average value of predetermined data blocks according to a first divisor used to calculate the moving average value;
- and
- calculating a moving average value of a resync pattern portion inserted between the predetermined data blocks according to a second divisor used to calculate the moving average value that is less than the first divisor used to calculate the moving average value.
A data reproduction device for calculating an amount of change in a DC component of a reproduction wave form, correcting an expected value in response to a moving average value of the amount of change in the DC component, and reproducing data in response to the corrected expected value, the device comprising:
- a present DC component change amount calculating unit for calculating a present amount of change in the DC component;
- and
- a moving average value calculating unit for calculating a moving average value of the present DC component change amount and a past DC component change amount,
- the moving average value calculating unit calculating a moving average value of a DC component change amount corresponding to predetermined data blocks according to a first divisor used to calculate the moving average value, the moving average value calculating unit calculating a moving average value of a resync pattern portion inserted between the predetermined data blocks according to a second divisor used to calculate the moving average value that is less than the first divisor used to calculate the moving average value.
Dependencies are inferred from the claim text.