摘要 |
PURPOSE:To obtain a disk having high sensitivity, a long life and high reliability, by placing 2 transparent substrates opposite to each other with a heat insulating layer made of a fibrous org. material in-between. CONSTITUTION:A disk is composed of transparent polymethyl methacrylate substrates 51, a recording medium 52 made of a metal, a metalloid or an org. material, a heat insulating layer 53 made of natural fiber, cellulose fiber or other fiber, and spacers 54. Since the fibrous heat insulating layer 53 is present between the 2 substrates 51, the substrates 51 are hardly warped and waved, and they undergo little change with the passage of time. Accordingly, the disk with high sensitivity and high reliability is obtd. |