| 摘要 |
PURPOSE:To realize the high-density recording and reproduction by carrying out the recording and reproduction with insertion of the pilot signals or the frequency region different with every adjacent tracks into the main signal bit row for the recording and reproduction and thus realizing the recording to the disk without grooves or the like via one piece of the light beam. CONSTITUTION:Gate 11 and switch 9 are controlled via input switch pluse 8, and adder 12 generates the composite pilot signals obtained by piling the pilot signals of different frequency regions and given from switch 9 onto the frequency signals which pass through gate 11 with every turning cycle of the disk. This composite signal is then added to the main signal underwent the FM modulation at adder 13 to be turned into the signal in which the pilot signal of different frequency regions with every adjacent track is added into the main signal bit row. Accordingly, the light beam exclusive for the pilot signal becomes unnecessary with use of the light beam which is modulated by the signal obtained above. And thus the high-density recording becomes possible for the disk with no groove via one piece of light beam. At the same time, the before- and after-pass states of the track can be decided by the pilot signals featuring different frequency regions with every adjacent track at the reproduction, thus ensuring the simple and assured tracking. |
