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US 7,030,788 B2Granted
Data recording medium, data recording method, and apparatus
AssigneeSony Disc & Digital Solutions Inc.
InventorsToru Aida, Toshihiko Senno
Life of this patent
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AssigneeSony Disc & Digital Solutions Inc.
InventorsToru Aida, Toshihiko Senno
Estimating the term…
Output data of a multiplexer 11 is EFM-modulated by an EFM modulator 12. In the EFM modulation, merging bits that satisfy run length limit conditions Tmin=3 and Tmax=11 are selected. Among them, merging bits that converge DSV are selected. A run length controlling portion 13 detects a particular data pattern that causes DSV to increase as large as a data read error takes place and controls the EFM modulator 12 so that the run length limit conditions of the EFM are loosened. As a result, an increase of DSV is suppressed. Data is reproduced from a data recording medium on which the data has been recorded in such a manner and the reproduced data is decoded. The decoded data is re-encoded so as to record it to another recoding medium. When the data pattern is re-encoded, DSV increases. As a result, data cannot be correctly reproduced from the other recording medium. Consequently, a copying operation can be prevented.
A data recording medium on which digital data is recorded using a digital modulating system for converting a data symbol of a predetermined number of bits into a code symbol of a larger number of bits than the data symbol and generating record data whose run length is limited,
A data recording method in which digital data is recorded using a digital modulating system for converting a data symbol of a predetermined number of bits into a code symbol of a larger number of bits than the data symbol and generating record data whose run length is limited, the data recording method comprising the steps of:
A data recording apparatus for recording digital data using a digital modulating system for converting a data symbol of a predetermined number of bits into a code symbol of a larger number of bits than the data symbol and generating record data whose run length is limited,
Dependencies are inferred from the claim text.