Patent ID: 7911913
Filing Date: 2011-03-22
Classification: G11B

Abstract:
1. An information recording apparatus for recording information on a multi-layered optical information recording medium having a recording material, which has light reaction property and/or thermal chemical reaction property and which changes quality due to irradiated light and/or heat generated by the light, and including an altered layer in which the recording material is already altered and a non-altered layer in which the recording material is not yet altered alternately existing in plurals, the information recording apparatus comprising: a light source to emit a recording light having a predetermined wavelength; a focal position control unit to control a focal position of the recording light emitted from the light source; and an objective lens, arranged at a post-stage of the focal position control unit, to collect the recording light; wherein the recording material at the focal position is altered through heat by the recording light to record information on the optical information recording medium as a recording mark, wherein the wavelength of the recording layer has a large difference between absorptance with respect to the altered layer and absorptance with respect to the non-altered layer.