| 摘要 |
PURPOSE:To simplify production by coating a metal and a dielectric on the insulator of a round plane plate form and by providing information recording means such as a groove and a concave on the dielectric and by laminating a lubricant on the surface of the dielectric. CONSTITUTION:Disc 21 brought into contact with reproducing stylus 31 is rotated in the arrow A direction. The BC direction indicates the diameter direction. Track 22 of an arc groove is formed spirally on the surface of disc 21. Depth l1 of square slot 23 on the locus of track 22 is uniform, however, width l2 and inter-slit distance l3 are different according to signal information. Metal 26 and dielectric 27 are coated on insulator 25 of disc 21, and oil 28 is coated on the surface. By this structure, production is simplified, and the production time and labor is reduced, and generation of production miss is reduced. |
