| 摘要 |
PROBLEM TO BE SOLVED: To prevent the infiltrating of a coating liquid for spin coating to the rear surface of a disk, to make tracking normal and to eliminate hindrance to recording and reproducing by providing the end face of a disk substrate with a projecting body in an annular form. SOLUTION: Grooves for tracking are formed on one surface of the substrate 12 consisting of a polycarbonate resin to form a recording surface. The back coating surface of the substrate 12 is coated with a resin layer 5 at a uniform thickness by a spin coating method. The substrate 12 is provided with the projecting body 13a having the surface flush with the back coating surface of the substrate in the annular form on the end face near the back coating surface. As a result, the coating liquid is blocked by the projecting body 13a without arriving at the recording surface even if the coating liquid spreads to the outer side and tends to infiltrate to the recording surface side at the time of coating the substrate with the resin layer 5 by the spin coating method. The tracking is thereby made normal and the high quality and high reliability are embodied without the hindrance to recording and reproducing. |
