| 摘要 |
PURPOSE:To prevent errors in information recording and reproduction, by the constitution that a plurality of discs having a radiant ray sensing layer on the surface are overlapped via a spacer to form a hollow part with the radiant ray sensing layer as the inside and a hygroscopic agent is provided to absorb water content of the hollow part. CONSTITUTION:A substrates 1 being a transparent disc have a round hole at the center, and the two substrates are overlapped with a spacer 2 provided at the outer end and a spacer 3 provided at the innner end in-between. A radiant ray sensing layer 4 is provided at the inside of the substrates 1, and the layer 4 is protected from damages through sealing with the substrate 1, the spacers 2 and 3. Since a hygroscopic agent 5 is provided at the external circumference of the spacer 3 and at the inner circumference of the spacer 2, the water content is not entered to the hollow part through gaps among the substrates 1 and the spacers 2 and 3. |
