Patent ID: 7507523
Filing Date: 2009-03-24
Classification: G11B,Y10S

Abstract:
1. An optical information recording medium comprising: a transparent substrate having a concentric circular guide groove or a spiral guide groove, said guide groove having land portions and groove portions formed thereon; and a phase change type recording layer on said transparent substrate; wherein information that indicates a standard recording linear velocity Vr and/or a maximum recording linear velocity Vh is stored on the medium, said stored information being recorded onto said substrate; wherein, while irradiating on land portions or groove portions formed on said guide groove energy enabled to melt the material of said phase change type recording layer and while increasing a linear velocity of said medium and scanning, the linear velocity at which the reflectivity of said optical information recording medium decreases, in comparison to that before the energy is radiated, is defined as uppermost recrystallization linear velocity V; wherein the uppermost recrystallization linear velocity V at the time when a focused semiconductor beam irradiates said groove portions or land portions of said guide groove satisfies a relation, the focused semiconductor beam being used for recording or reproducing, wherein a track pitch of said guide groove is between 0.2 and 1.4 μm, and the uppermost recrystallization linear velocity V is between 16 and 24 m/s.