| 摘要 |
PURPOSE:To add a write function based on a pit string provided in advance by irradiating a laser beam modulated by optional information to a region between pit strings on an optical disc face so as to make the 2nd recording pit string. CONSTITUTION:Reproducing only pit strings 11 having an interval of t2=2.5-3.5mum are provided on one side of a transparent resin base 1. Onto the face of a flat region 12, for example, a Te group optomagnetic medium layer 3 is vapor-deposited by a thickness of several tens-several thousands A. Information is read as to pits 11 by a conventional method. The laser beam modulated based on optional recording information is irradiated to the region 12 from the same direction A to form recording pits 14 onto the layer 3. In this case, two auxiliary beams are used for the tracking servo based on the reproduction only pit strings 11. The pits 14 are read by the same method as that for the reproduction only pits and tracked by the same method as that at recording. Through the constitution above, no crosstalk at reproduction takes place, reproduction/recording are attained by the same optical head and the device is simplified. |
