| 摘要 |
PURPOSE:To obtain uniform data bit independent of linear velocity by simplifying information recording at a high linear velocity while adding the optical output at the constant power level according to the recording linear velocity at the time of recording. CONSTITUTION:The diameter of a disk 8 is detected by a position detecting device 1, and an output signal which is generated when a head moves from the outer peripheral side to the inner peripheral side is given to a constant current generation circuit 4. A tachometer 2 gives the output according to the number of rotations to the constant current generation circuit 4. By obtaining the constant current corresponding to the linear velocity of a disk from both outputs, a write circuit 6 outputs the sum of the recording current and the constant current to a head 5 at the recording. In this case, the intensity of the constant current is adjusted to be lower than the write current at all times. Thus, the optical power to be outputted to the recording surface of the disk makes the bit recording while adding the laser beam at the constant level according to the constant current suitable for the recording linear velocity. |
