| abstract |
PURPOSE: To reduce variation in reflectance caused by face webbing of a medium and to obtain stable optical recording characteristics by providing a reflection preventing film which consists of such a material having higher transmittance for light than the case and the medium, in the light path on the case of the medium and on the optical recording medium itself. n CONSTITUTION: Reflection preventing films 2a, 2b are provided on the case and the optical recording medium, respectively. The reflection preventing film 2a comprising MgF 2 having specified thickness is formed by sputtering on the inner surface of the transparent acrylic resin case 1 having specified thickness. An Au reflecting film 10 is formed on the glass substrate 4, which is then coated with a recording film 3 comprising naphthalocyanine. Further the reflectance preventing film 2b comprising CeO 2 and having specified thickness is formed on the recording film 3 by sputtering. The obtd. disk in the case shows little variation of reflectance, for example within 5%, during rotated, and the medium has stable recording/reproducing characteristics for semiconductor laser light of 830nm wavelength. Moreover, the org. recording medium is shielded from UV ray by the case and has superior environmental property. n COPYRIGHT: (C)1991,JPO&Japio |