| 摘要 |
PURPOSE:To prevent the optical disk from receiving the disturbance of groove addresses even if the signal of a specific frequency is recorded thereon by forming the intermittent parts of the groove addresses formed by intermission of guide grooves longer than continuous existence parts. CONSTITUTION:The intermission of the guide grooves 1 for the groove address signal A constituted by combination of specified time intervals T, 2T is so determined that the length L1 of the intermittent parts is longer by an much as the spot diameter 2 of a recording light beam than the length L2 of the continuous existence like the signal B. The quantity of the light reproduced by a decrease in the reflectivity by the grooves is small in the guide grooves if this groove address information is reproduced. Since the reflectivity is high in the intermittent parts of the grooves, the quantity of the reproduced light increases and, therefore, the reproducing groove address signal C is obtd. The duty of the groove address signal after signal recording is consequently correctly reproduced and the reproducing groove address signal has no spectral distribution at the specific frequency. The optical disk is prevented from receiving the disturbance of the groove address in this way even if the signal of the specific frequency is recorded thereon. |
