Patent ID: 7903535

Claim:
An optical information recording medium comprising: a substrate having lands and grooves; a recording layer including a dye disposed on the substrate; a reflection film disposed on the substrate in a thickness direction; a main information recording area; and a sub-information recording area in a radial direction, wherein the sub-information recording area includes a bar code composed of a plurality of bars crossing grooves and lands and aligned circumferentially, said bars being recorded using the recording layer with the reflection film and defined by an area of the dye decomposed by a laser beam, said area also being defined by grooves and lands thermally deformed by the dye decomposition, wherein a height difference between the thermally deformed lands and the thermally deformed grooves in the bars is smaller as a result of the thermal deformation than a height difference between lands and grooves in a portion other than the bars in the sub-information area.