| 摘要 |
PURPOSE:To prevent both the S/N and C/N of a reproduction signal by absorbing the light transmitted thorugh a recording film of a 2-sided optical recording medium by an adhesion layer and preventing the diffused reflection on the interface between the recording film and the adhesion layer with formation of a protection film. CONSTITUTION:The 1st optical recording medium is obtained by forming a recording film 2 having variable reflection factors with ierradiation of the laser light onto a substrate 1 made of the acrylic resin which is optically transparent. While the 2nd optical recording medium is obtained by forming a recording film 2' on a substrate 1'. Then the 1st and 2nd recording media are adhered together via an opaque adhesion layer at the side of each recording film of both recording media. While the protection layers 5 and 5' of a transparent material are provided between the layer 4 and both films 2 and 2'. A coloring agent which absorbs light is mixed into the layer 4 and therefore the beams transmitted through the films 2 and 2' are absorbed by the layer 4 to produce no undesired reflected light. Thus the noise level is also reduced. The noise level can be reduced less by setting the thickness of both layers 5 and 5' at >=2mum. In such a way, the deterioration is prevented for both the S/N and C/N. |
