| 摘要 |
PURPOSE:To allow recording and reproduction by laser light without dew condensation with an environmental change such as temp. and humidity change by using a resin having >=1% water absorptivity to form a resin film which is joined in the non-recording region of an inner circumferential side and outer circumferential side respectively of a resin substrate. CONSTITUTION:A disk-shaped resin film 2 is joined by forming a joint region 14 in the non-recording region 18 on the inner circumferential side of the resin substrate 11 and is joined by forming a joint region 15 in the non-recording region 19 on the other circumferential side of the resin substrate 11. The disk- shaped resin film 2 is the resin film having >=1% water absorptivity. Excess steam is, therefore, absorbed by the resin film 12 having the high water absorptivity even if the steam is saturated near the resin film by a sharp temp. fall. The tendency to dew condensation is hardly admitted in this way. |
