Patent ID: 7301875

Claim:
An information recording device for writing binary data on a write-once type information recording medium having a recording material that gives rise to an irreversible change to the light reflecting condition thereof when irradiated with light of not less than a predetermined power level by forming a continuous row of recording marks, which are parts where the light reflecting condition has changed, and spaces, which are parts where the light reflecting condition has not changed, the device comprising: a modulation section adapted to generate the binary data to be written onto the write-once type information recording medium by modulating the input information; a laser write section adapted to irradiate a laser beam onto the write-once type information recording medium, moving the position of the laser beam irradiation spot relative to the write-once type information recording medium; and a control section adapted to control the laser write section according to the binary data and forming a row of recording marks and spaces corresponding to the code string of the binary data; the modulation section being so adapted that, if the channel clock cycle of the binary data is T, it modulates the input information such that the shortest identical code length of the binary data is not less than 2×T; the control section being so adapted that when forming a recording mark having a length of n 1 ×T, n 1 being an integer not smaller than 2, a pulse beam is irradiated onto the write-once type information recording medium for n 1 /2 times, decimals, if any, being to be rounded down, and, when forming a recording mark having a length of not smaller than n 2 ×T, n 2 being an even number not smaller than 6, a pulse beam is irradiated onto the write-once type information recording medium for n 2 /2 times with all the intermediate pulse beams synchronized with the phase of the channel clock except the leading pulse beam and the tail end pulse beam, whereas, when forming a recording mark having a length of not smaller than n 3 ×T, n 3 being an odd number not smaller than 6, a pulse beam is irradiated onto the write-once type information recording medium for (n 3 −1)/2 times with all the intermediate pulse beams delayed from the phase of the channel clock by T/2 except the leading pulse beam and the tail end pulse beam.