Sony Corporation

Munetoshi Moriichi

Takashi Sasaki

Mitsuyuki Bamba

Yoshiyasu Masuda

Atsushi Mori

Satoshi Kitani

In a writing device for writing data at 1-time or higher recording rates, a first delay circuit capable of variably controlling a delay time in units of a relatively long time and a second delay circuit capable of variably controlling a delay time in units of a relatively short time are employed in a combined manner. A laser drive pulse can be controlled in the direction of the time base with high accuracy corresponding to any recording rates ranging from 1-time to higher, e.g., 8- or 12-time, speeds without using very large number stages of delay gates.

Writing device

A recording apparatus generates a first pulse (EQEFM signal) in accordance with recording data such as an EFM signal. A second pulse (first overdrive pulse) to be combined with substantially the leading edge of the first pulse is generated. A third pulse (end overdrive pulse) to be combined with substantially the trailing edge of the first pulse is generated. The first, second, and third pulses are combined to synthesize a driving pulse, and the driving pulse is supplied to a laser unit. At least one of the first, second, and third pulses is controlled so that one of the level and the pulse duration thereof is varied in accordance with the length of formed pits and lands.

Recording apparatus and recording method

In the case where data are recorded in a medium, after a specific type of a medium in which recording is performed is set, if it is detected that information is recorded on an address of specific position at which decoding information is to be located, then data at a section in which the decoding information is located are replaced with predetermined information and recording is performed. Alternatively, when data are to be reproduced from a medium, after it is discriminated that data are reproduced from a medium of a specific type, if it is determined that data are reproduced from an address of specific position at which the decoding information is to be located, then reproduction data of a section in which the decoding information is located is replaced with predetermined information and outputted. Thus, when contents data are recorded in (or reproduced from) a medium such as a recordable DVD standard, copy of data requiring copyright protection can be limited easily and reliably while a recording area of a medium is being used effectively.

Recording method, recording apparatus, reproducing method and reproducing apparatus

A method for recording on a write-once type optical disc. A laser light beam excited to light emission by a recording pulse having a pulse width corresponding to the length of a pit formed, with the recording power of substantially the leading end of the pulse being stepped over plural stages, is illuminated on a write-once type optical disc for recording. This enables recording with an optimal pit shape at a speed faster than a quadrupled speed, such as at an octupled speed or a duo-deca-tupled speed.

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Saitama, Japan

Munetoshi Moriichi