Patent ID: 6792613
Filing Date: 2004-09-14
Classification: G11B

Abstract:
An optical information recording medium having a recording layer formed on a transparent substrate having a spiral pregroove formed thereon, wherein:a track pitch Tp of the pregroove is 1.0 &mgr;m&lE;Tp&lE;1.2 &mgr;m; a half-width Gw of the pregroove is 0.25 &mgr;m&lE;Gw&lE;0.50 &mgr;m; a depth Gd of the pregroove is 100 nm&lE;Ga&lE;300 nm; and a width Lw of a land formed between the pregrooves is Lw&gE;0.6 &mgr;m.