Patent ID: 7203150

Claim:
A recording system for an optical recording medium, the system including an optical recording medium provided with at least a light-transmitting layer covered with a recording layer formed on a support substrate, and a radiation optical system for recording, reproducing, and erasing information on the recording layer by radiating the optical recording medium from the light-transmitting layer side with a laser beam at a recording power Pw and an erasing power Pe, wherein the radiation optical system is designed to radiate the recording layer with a laser beam of wavelength 450 nm or less through a lens system having an objective lens of numerical aperture 0.7 or more, the optical recording medium is designed to be able to record or erase information on the recording layer when the relation between the recording power Pw of the laser beam and the erasing power Pe satisfies 0.75≦Pe/Pw≦0.87, and the recording layer is provided, on its light-transmitting layer side, with a heat sink layer.