OPTICAL DISK AND PRODUCTION THEREOF

摘要

PURPOSE:To form pits and grooves having good tracking and excellent recording and reproducing characteristics with the optical disk having a reproduction-only region and a recordable region. CONSTITUTION:Arrays of the projecting pits 11 are formed along spiral tracks of the reproduction-only region 14 on the surface of the substrate of the optical disk and the recessed grooves 12 are formed in the recordable region 13 thereof. The recessed grooves 12 are formed between the projecting parts 15 formed between the tracks on the main surface of the substrate 10. The projecting pit arrays and the recessed grooves are formed along the continuous single track by two stages of rugged structures on the surface of the substrate 10 in this way. A master disk is formed by using two sets of laser pickups, one set of which exposes a photoresist film along the top of the tracks and the other set of which exposes the photoresist along the inter-track spacings. The substrate such as the substrate mentioned above is formed by profiling this master disk.