| 摘要 |
PURPOSE:To reduce the radio of the generation of broken base and regenerate at high contrast by regulating sizes of patterns of information bits formed on the mold surface of an injection molding die and pitches of information bit patterns in a specific range. CONSTITUTION:The sizes of an information bit section 2 is 2-15mum length (b) in the direction parallel with a tracking group 1, 1-6mum width (a) in the vertical direction, 300-3500Angstrom height (c) and pitch (d) of 1.8 times or more the length (b) of pit. At that time, the generation of breakage is 20% or less. When coating of a recording layer is applied, the relationship between the film thickness of an information bit section and the film thickness of a rand section can be made optimum, and contrast becomes 0.35 or more, to get an information recording medium of more reliability can be provided. An injection molded die is manufactured by photolithographic technique, for instance, a Cr film is made on a glass base at the height of a pattern, over which photoresist is applied and light exposure, development and etching are carried out. |
