Apparatus for recording and reproducing data on a disk

Claim 2

A disk data recording apparatus for recording binary data having a plurality of 1s and a plurality of 0s in the form of marks and spaces on a disk by allocating a number of consecutive 1s to the mark and a number of consecutive 0s to a space, comprising: a start end pulse generating means for generating a start end pulse of a first predetermined width at a start end of the consecutive 1s; a burst gate pulse generating means for generating a burst gate pulse when the number of the consecutive 1s is more than a predetermined number; a termination end pulse generating means for generating a termination end pulse of a second predetermined width at a termination end of the consecutive 1s; a mark/space length detecting means for producing an nT mark signal when the number of the consecutive 1s is n and an mT space signal when the number of the consecutive 0s is m where n and m are natural numbers as contained in a stream of the data and T is width of a clock pulse; an encoder for producing from the nT mark signal and the mT space signal select signals composed of a start end select signal for selection of a start end position data and a termination end select signal for selection of a termination end position data; a start end selector for selecting one of a plurality of start end position data in response to the start end select signal; a start end sample/hold means for updating the start end position data if the start end sample/hold means receives the start end pulse and holding a previous start end position data if the start end sample/hold means does not receive the start end pulse; a start end programmable delay line for delaying the start end pulse by a time of delay determined by an output of the start end sample/hold means to output a delayed start end pulse; a termination end selector for selecting one of the termination end position data in response to the termination end select signal; a termination end sample/hold means for updating the termination end position data if the termination end sample/hold means receives the termination end pulse and holding a previous termination end position data if the termination end sample/hold means does not receive the termination end pulse; a termination end programmable delay line for delaying the termination end pulse by a time of delay determined by an output of the termination end sample/hold means to output a delayed termination end pulse; an AND gate for calculating a logical product of the burst gate pulse and the clock pulse to produce a burst signal; an OR gate for calculating a logical sum of the delayed start end pulse, the burst signal, and the delayed termination end pulse to produce a recording signal; a laser beam generating means for generating a laser beam whose power changes over between a first power and a second power arranged according to the recording signal where the first power>the second power; and an optical head for focusing the laser beam on to a surface of the disk to record the recording signal.

Claim 3

A disk data recording apparatus according to claim 1, wherein the laser beam generating means comprises a main current source for supplying a laser diode with a current required for generating the second power of the laser beam, a sub current source connected in parallel with the main current source for supplying the laser diode with a current required for generating the first power of the laser beam, a switch for switching the sub current source according to the recording signal, and the laser diode of n-type driven by the main current source and the sub current source and connected in series with the main current source.

Claim 4

A disk data recording apparatus according to claim 1, wherein the laser beam generating means comprises a main current source for supplying a laser diode with a current required for generating the first power of the laser beam, a sub current source connected in parallel with the laser diode for releasing a portion of a main current from the main current source to supply the laser diode with a current required for generating the second power of the laser beam, a switch for switching the sub current source according to the recording signal, and the laser diode of P-type driven by the main current source and the sub current source.

Claim 5

A disk data recording/reproducing apparatus for recording data in the form of marks and spaces on a disk by allocating a number of consecutive 1s to a mark and a number of consecutive 0s to a space, and for reproducing the data recorded on the disk, comprising: a start end pulse generating means for generating a start end pulse of a first predetermined width at a start end of the consecutive 1s; a burst gate pulse generating means for generating a burst gate pulse when the number of the consecutive 1s is more than a predetermined number; a termination end pulse generating means for generating a termination end pulse of a second predetermined width at a termination end of the consecutive 1s; a mark/space length detecting means for producing an nT mark signal when the number of the consecutive 1s is n and an mT space signal when the number of the consecutive 0s is m where n and m are natural numbers as contained in a stream of the data and T is a width of a clock signal; an encoder for producing from the nT mark signal and the mT space signal select signals composed of a start end select signal for selection of a start end position data and a termination end select signal for selection of a termination end position data; a start end selector for selecting one of a plurality of start end position data in response to the start end select signal; a start end sample/hold means for updating the start end position data if the start end sample/hold means receives the start end pulse and holding a previous start end position data if the start end sample/hold means does not receive the start end pulse; a start end programmable delay line for delaying the start end pulse by a time of delay determined by an output of the start end sample/hold means to output a delayed start end pulse; a termination end selector for selecting one of a plurality of termination end position data in response to the termination end select signal; a termination end sample/hold means for updating the termination end position data if the termination end sample/hold means receives the termination end pulse and holding a previous termination end position data if the termination end sample/hold means does not receive the termination end pulse; a termination end programmable delay line for delaying the termination end pulse by a time of delay determined by an output of the termination end sample/hold means to output a delayed termination end pulse; an AND gate for calculating a logical product of the burst gate pulse and the clock pulse to produce a burst signal; an OR gate for calculating a logical sum of the delayed start end pulse, the burst signal, and the delayed termination end pulse to produce a recording signal; a laser beam generating means for generating a laser beam whose power changes over between a first power and a second power according to the recording signal where the first power>the second power; and an optical recording head for focusing the laser beam on to a surface of the disk to record the recording signal; an optical reproducing head for reading the data from the disk to produce a reproduced signal; a preamplifier for amplifying the reproduced signal; an equalizer for equalizing frequency characteristic of the reproduced signal; and a comparator for binalizing the reproduced signal to produce a reproduced data.

Claim 6

A disk data recording/reproducing apparatus for recording data in the form of marks and spaces on a disk by allocating a number of consecutive 1s to a mark and a number of consecutive 0s to a space, and for reproducing the data recorded on the disk, comprising: a start end pulse generating means for generating a start end pulse of a first predetermined width at a start end of the consecutive 1s; a burst gate pulse generating means for generating a burst gate pulse when the number of the consecutive 1s is more than a predetermined number; a termination end pulse generating means for generating a termination end pulse of a second predetermined width at a termination end of the consecutive 1s; a mark/space length detecting means for producing an nT mark signal when the number of the consecutive 1s is n and an mT space signal when the number of the consecutive 0s is m where n and m are natural numbers as contained in a stream of the data and T is a width of a clock signal; an encoder for producing from the nT mark signal and the mT space signal select signals composed of a start end select signal for selection of a start end position data and a termination end select signal for selection of a termination end position data; a start end selector for selecting one of a plurality of start end position data in response to the start end select signal; a start end sample/hold means for updating the start end position data if the start end sample/hold means receives the start end pulse and holding a previous start end position data if the start end sample/hold means does not receive the start end pulse; a start end programmable delay line for delaying the start end pulse by a time of delay determined by an output of the start end sample/hold means to output a delayed start end pulse; a termination end selector for selecting one of a plurality of termination end position data in response to the termination end select signal; a termination end sample/hold means for updating the termination end position data if the termination end sample/hold means receives the termination end pulse and holding a previous termination end position data if the termination end sample/hold means does not receive the termination end pulse; a termination end programmable delay line for delaying the termination end pulse by a time of delay determined by an output of the termination end sample/hold means to output a delayed termination end pulse; an AND gate for calculating a logical product of the burst gate pulse and the clock pulse to produce a burst signal; an OR gate for calculating a logical sum of the delayed start end pulse, the burst signal, and the delayed termination end pulse to produce a recording signal; a laser beam generating means for generating a laser beam whose power changes over between a first power and a second power according to the recording signal where the first power>the second power; and an optical recording head for focusing the laser beam on to a surface of the disk to record the recording signal; an optical reproducing head for reading the data from the disk to produce a reproduced signal; a preamplifier for amplifying the reproduced signal; an equalizer for equalizing frequency characteristic of the reproduced signal; and a comparator for binalizing the reproduced signal to produce a reproduced data.