Patent ID: 7092343
Filing Date: 2006-08-15
Classification: G11B

Abstract:
1. An optical recording and reproducing method for performing at least recording or reproduction of information with respect to an optical recording medium, characterized in that the optical recording medium has a plurality of information-recording layers between one principal plane on a side where light enters said optical recording medium and the other principal plane opposite thereto, a first information-recording layer that is nearest to said other principal plane is formed of a phase-modulation type information-recording layer and a second information-recording layer is formed of a reflectance-modulation type information-recording layer, and upon incidence of light from the side of said one principal plane, recording or reproduction of information is performed by the phase-modulation method with respect to said first information-recording layer, and recording or reproduction of information is performed by the reflectance-modulation method with respect to said second information-recording layer wherein a change rate (R the same change rate (R