Write-once optical record medium

摘要

In a write once optical recording medium comprising a recording layer and a light transmitting protective layer formed successively on a supporting body, for recording and reproduction by irradiating a laser beam of a 380 to 450 nm wavelength from the light transmitting protective layer side, lambdmax<=370 nm on the premise that the wavelength providing the peak optical absorption coefficient of the recording layer is defined to be lambdmax.