OPTICAL RECORDING/REPRODUCTION DISC

摘要

PCT No. PCT/JP83/00029 Sec. 371 Date Oct. 4, 1983 Sec. 102(e) Date Oct. 4, 1983 PCT Filed Feb. 3, 1983 PCT Pub. No. WO83/02845 PCT Pub. Date Aug. 18, 1983.An optical recording/reproducing disc is formed of round plastic plates between which is a recording layer capable of optically recording and reproducing signals, and a round protective layer of plastic material provided on the recording layer and having at the outer peripheral end a projection higher by 10 to 200 mu than the inner peripheral surface of an effective recording/reproducing surface. Thus, when the disc is placed on a flat plane, a space is formed between the flat plane and the recording layer due to the projection, thereby preventing flaws from being produced by contact with dust or a foreign object.