Apparatus for recording and reproducing data on a disk

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.