Sixbey, Friedman, Leedom & Ferguson
Information recording medium having high modulation degree
 The information recording medium comprises a substrate provided with a prepit area and a pregroove area, a dye layer on the substrate and a reflecting layer on the dye layer, wherein the dye layer is a continuous layer formed on both the prepit area and the pregroove area, and the prepit area has a high modulation degree not less than 50%. Its embodiments are as follows: A medium in which a difference between an optical thickness of the dye layer on the bottom portion of a pregroove or a prepit and that of the dye layer on the land portion or a portion between prepits is not more than .lambda./8; one in which a prepit has a half width of 0.2 to 1.4 .mu.m and a depth of 150 to 400 nm, the pregroove has a half width of 0.2 to 1.4 .mu.m and a depth of 70 to 200 nm, the depth of the prepit is larger than the depth of the pregroove by not less than .lambda./8; and one in which wherein a relationship between a depth of a prepit and a thickness of said dye layer on the prepit and that between a depth of a pregroove and a thickness of a dye layer on the pregroove satisfies the specific conditions; and one in which least one of the prepit area and the pregroove area may be present in two or more places are disclosed. 
Fuji Photo Film Co., Ltd.
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Yoshihisa Takahito Mitsuru
Usami Miyoshi Sawano