| 摘要 |
PURPOSE:To reduce jitter components due to variance in optimum recording condition and to improve recording density by writing a reference linear speed, recording beam diameter, optimum recording power at room temperature, etc., on a photomagnetic recording carrier. CONSTITUTION:When 12 photomagnetic disks of the same structure are manufactured by the same manufacturing method, the optimum recording power has variance from 4 to 5.6mW on conditions of a 6m/sec linear speed and a 400oe recording magnetic field. The optimum power of each disk is recorded in the 0-address sector 2 at the outermost peripheral part of the disk. When recording or reproduction is performed, the disk 1 is loaded and the signal of the 0-address sector 2 is read right after the drive is driven and stored in a memory. When a pickup is moved to a place where data is to be recorded, recording power is calculated from the signal stored in the memory, distance from the center of disk rotation, etc., and the recording is carried out with the found recording power. |
