| 摘要 |
PURPOSE:To enable adhesion of dust or dirt onto an incidence surface of laser light to be restricted and the adhered dust or dirt to be removed easily by providing an oil repellent and/or lubricating protection film on an irradiation surface of laser beam. CONSTITUTION:A recording layer 3 is provided on a substrate 1 and information is recorded and reproduced by irradiating the recording layer 3 with a laser beam. In this case, phosphazene resin which is diluted by an organic solvent is coated, as a protection film, on a transparent substrate 1 where laser beam enters. This phosphazene resin is an oil repellent resin. When an oil drop 12 of a mineral oil is, for example, dropped on this resin, a contact angle theta formed between this oil drop 12 and the protection film 11 is equal to or more than 40 degrees, thus enabling the oil drop 12 to be repelled fully. Therefore, it prevents smear of dust/dirt, oil mist etc. from being adhered and enables it to be wiped off easily even if it is adhered to. |
