| 摘要 |
PURPOSE:To prevent the illegal duplication of soft recorded on an optical disk by providing a dummy pit for the optical disk, including data relating to the position and discrimination of the dummy pit and providing a dummy pit discriminating device corresponding to the optical disk. CONSTITUTION:The optical disk 11 is rotated by a rotating device 11, and an optical pick up device 2 reads the optical disk 11 and obtains a signal 6. The magnitude of the signal 6 is different in each part because the interference of laser in the part of the dummy pit 21 is smaller than in the part of a real pit 22. In accordance with data relating to the position and discrimination of the dummy pit 21 recorded on the optical disk, the dummy pit discriminating device 12 discriminates whether or not the part of the dummy pit has a bit, and transmits a corrected signal to a signal demodulator 3, which outputs said signal as an original one before recording it on the disk. The output of the signal demodulator 3 is also transmitted to the dummy pit discriminating device 12, which obtains data relating to the position and discrimination of the dummy pit recorded on the optical disk. |
