Method of recording information on optical recording medium, and information recording and reproducing apparatus

An information recording and reproducing apparatus for irradiating a pulse-modulated laser beam through a light-transmitting layer on a recording layer of an optical recording medium including the recording layer and the light-transmitting layer formed to cover the recording layer so as to modulate data to be recorded to have a length of a recording mark along a track of the recording layer and to make the length of the recording mark correspond to an integral multiple nT of T where T is one clock cycle, the information recording and reproducing apparatus comprising at least:

• an optical device for irradiating the laser beam on the optical recording medium;
• and
• a laser driving device for supplying a laser driving signal so as to modulate and control the laser beam to a pulse series including a write pulse of a recording power and a cooling pulse of an approximately base power, wherein
• the laser driving device supplies the laser driving signal corresponding to the write pulse and the cooling pulse by a method of recording information,
• the method is comprising the steps of:
• pulse-modulating a laser beam so as to create a pulse series including a write pulse of a recording power and a cooling pulse of an approximately base power;
• and
• irradiating the pulse-modulated laser beam on a recording layer included in the optical recording medium for recording, whereby data to be recorded is modulated to have a length of a recording mark along a track of the recording layer and the length of the recording mark is made to correspond to an integral multiple nT of T where T is one clock cycle, wherein
• the same number of the write pulses and the cooling pulses are used when an nT recording mark with the n being 4 or larger is to be recorded;
• and an average width AveTc for a single cooling pulse width Tc is set to satisfy:
• 1.0<AveTc/T<1.6, and a total pulse width SumTc of the used cooling pulses is set to satisfy:
• 0.5≦SumTc/nT≦0.8.