| 摘要 |
PROBLEM TO BE SOLVED: To provide an information recording medium which can detect an excellent signal by preventing small modulation factor and deviation of symmetry due to large amount of a dyestuff in a pit part when a prepit is filled with the dyestuff and making absorbance in a RAM region higher than absorbance in a ROM region by making average film thickness in the RAM region larger than that in the ROM region and changing a method for applying an organic dyestuff material or the like in a hybrid type information recording medium having the ROM region and the RAM region. SOLUTION: The information recording medium is provided with a recording layer or a metallic layer on a light-translucent substrate directly or via a substrate layer, contains the RAM region 11b where information is recorded/ reproduced/erased and the ROM region 11a where information is formed as a projected-recessed pit row in advance and then only reproduction is executed and is characterized by that average film thickness of the recording layer or of the metallic layer in the RAM region is larger than that in the ROM region. |
