Patent ID: 6914875

Claim:
An optical recording medium that can record information by irradiating laser beam to form recording marks on a recording layer and read the recorded information by irradiating a reading laser beam onto the recording mark; wherein said optical recording medium has virtual recording cells on said recording layer specified in an arbitrary unit length in a direction of relative movement between the laser beam and the recording layer and in a unit width in a direction that intersects the above-mentioned direction at a right angle and is continuously set in said direction of movement; said, recording layer on said virtual recording cells can form the recording marks with different sizes for each of said virtual recording cell in correspondence to the modulation of the irradiation time of the laser beam in five levels or more to perform multilevel recording of five levels or more of information by means of modulating the reflectance based on at least the area ratio out of the area ratio of the recording mark to the virtual recording cell and transmittance.