| 摘要 |
PURPOSE:To improve the weatherability, sensitivity and signal quality of an optical recording medium which is provided with a layer essentially consisting of a tin oxide on one side of a substrate and records and reads information by the irradiation of laser light by forming a silicon oxide layer between the substrate thereof and the layer essentially consisting of the tin oxide. CONSTITUTION:The tin oxide is selected in terms of weatherability and the size of a refractive index for the material of the 1st spacer layer 1 and the thickness thereof is so elected as to increase reflected light. Incident light through the substrate 10 is partly reflected by the boundary face between the substrate 10 and the 1st spacer layer 1, the boundary face between the 1st spacer layer 1 and the 2nd spacer layer 40 and the boundary face between the 2nd spacer layer 40 and air. The material and thickness of the 2nd spacer layer 40 are so selected as to decrease the reflected light. The difference in the rate of moisture absorption near both faces of the synthetic resin substrate is substantially eliminated by inserting the silicon oxide layer 2 between the synthetic resin substrate and the tin oxide layer 1 which is the 1st spacer layer and therefore, the generation of warpage is prevented. |
