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AssigneeSony Corporation
InventorToshihiro Fujiki
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There is provided an optical disc recording apparatus for generating a modulation signal having a signal level switched at a period which is an integral multiple of a basic period based on main information and controlling an optical beam applied to an optical disc based on said modulation signal to successively form, on said optical disc, pits and lands or marks and spaces having lengths which are represented by integral multiples of a basic length corresponding to said basic period. A sequence of data based on auxiliary information is modulated by a signal represented by a combination of a sequence of pseudo-random numbers and a predetermined periodic signal, and recorded traces of said pits or said marks are changed depending on the modulated sequence of data, thereby recording said auxiliary information on said optical disc. Accordingly, even if a pseudo-random number sequence is used for recording auxiliary information, by making it difficult to estimate the structure of the sequence of pseudo-random numbers, anyone who attempts to produce an illegal copy finds it difficult to duplicate an optical disc which has auxiliary information recorded thereon.
An optical disc recording apparatus for generating a modulation signal having a signal level switched at a period which is an integral multiple of a basic period in accordance with main information and controlling an optical beam applied to an optical disc based on said modulation signal to successively form, on said optical disc, pits and lands or marks and spaces having lengths which are represented by integral multiples of a basic length corresponding to said basic period, wherein a sequence of data based on auxiliary information is modulated by a signal represented by a combination of a sequence of pseudo-random numbers and a predetermined periodic signal, and recorded traces of said pits or said marks are changed depending on the modulated sequence of data, thereby recording said auxiliary information on said optical disc.
An optical disc recording apparatus for generating a modulation signal having a signal level switched at a period which is an integral multiple of a basic period in accordance with main information and controlling an optical beam applied to an optical disc based on said modulation signal to successively form, on said optical disc, pits and lands or marks and spaces having lengths which are represented by integral multiples of a basic length corresponding to said basic period, wherein a sequence of data based on auxiliary information is modulated by a signal represented by a combination of a sequence of pseudo-random numbers and a predetermined periodic signal, and the reflectance of an information recording surface of said optical disc is locally changed depending on the modulated sequence of data, thereby recording said auxiliary information on said optical disc.
A method of recording information on an optical disc by successively forming, on said optical disc, pits and lands or marks and spaces having lengths which are represented by integral multiples of a predetermined basic length to record main information on said optical disc, comprising the steps of:
A method of recording information on an optical disc by generating a modulation signal having a signal level switched at a period which is an integral multiple of a basic period in accordance with main information and controlling an optical beam applied to an optical disc based on said modulation signal to successively form, on said optical disc, pits and lands or marks and spaces having lengths which are represented by integral multiples of a basic length corresponding to said basic period, said method comprising the steps of:
An optical disc having pits and lands or marks and spaces having lengths which are represented by integral multiples of a predetermined basic length, successively formed to record main information on said optical disc, wherein a sequence of data based on auxiliary information is modulated by a signal represented by a combination of a sequence of pseudo-random numbers and a predetermined periodic signal, and recorded traces of said pits or said marks are changed depending on the modulated sequence of data, thereby recording said auxiliary information on said optical disc.
An optical disc having pits and lands or marks and spaces having lengths which are represented by integral multiples of a predetermined basic length, successively formed to record main information on said optical disc, wherein a sequence of data based on auxiliary information is modulated by a signal represented by a combination of a sequence of pseudo-random numbers and a predetermined periodic signal, and the reflectance of an information recording surface of said optical disc is locally changed depending on the modulated sequence of data, thereby recording said auxiliary information on said optical disc.
An optical disc reproducing apparatus for detecting a returning beam produced from an optical disc when an optical beam is applied to the optical disc, and processing a reproduced signal having a signal level changed in accordance with said returning beam to reproduce a sequence of data recorded on said optical disc, comprising:
A method of reproducing an optical disc by detecting a returning beam produced from an optical disc when an optical beam is applied to the optical disc, and processing a reproduced signal having a signal level changed in accordance with said returning beam to reproduce a sequence of data recorded on said optical disc, said method comprising the steps of:
Dependencies are inferred from the claim text.