Patent ID: 8125881

Claim:
An optical information recording medium storing information reproduced by irradiation of a light beam (wavelength=λr (nm)), comprising: a substrate on which a pit and/or groove corresponding to the information is formed; a temperature responsive layer made of a metal oxide compound, having a first surface on which the light beam is incident and a second surface opposite to the first surface, an optical property of the temperature responsive layer in the wavelength λr of the light beam-changing in response to a temperature rise caused by the irradiation of the light beam; and a reflection layer, positioned above the second surface of said temperature responsive layer, for reflecting the light beam to the temperature responsive layer, wherein λr−100<λa<λr where an optical absorption edge wavelength of the temperature responsive layer is λa (nm), the optical absorption edge wavelength is a wavelength corresponding to a band gap of the temperature responsive layer, the reflection layer includes an Al layer whose thickness is not less than 15 nm and less than 30 nm and first and second transparent protective layers each made of inorganic material, the first and second transparent protective layers being adjacent to both surfaces of the Al layer, respectively, and wherein the temperature responsive layer has a thickness in the range from 100 nm to 300 nm, and has a transmissivity indicative of a drop in said optical property of the temperature responsive layer in the wavelength of the light beam having been irradiated in response to a temperature rise.