OPTICAL INFORMATION CARRIER DISC

摘要

PURPOSE:To reduce a signal noise due to interference of reflected light by providing a protection coating film in which light absorbing particles having a size of at least <=1/3 of the minimum recorded signal pit size are mixed onto an information medium layer so as to decrease the reflected light from the protection coating film. CONSTITUTION:A translucent information medium layer 2 from which information is read by light is provided on a transparent base 1 and the protection coating film 8 is coated on the medium layer 2. The coating film 8 consists of a resin 9 being a base and particles 10 mixed to the resin and having the absorbing property to at least the laser beam 5. The size of the particles 10 is a size having the absorbing property to a laser beam 5 having a size at least <=1/3 of the minimum signal pit size recorded to the medium layer 2 and carbon black not absorbing ultraviolet ray is used. As the resin 9, an ultraviolet ray curing resin is used. Thus, the reflected light from the protection film 8 is reduced so as to reduce the signal noise due to interference of the reflected lights.