| 摘要 |
PURPOSE:To obtain an optimum function of optical modulation transmission from the outer circumference part to the inner circumference part of an optical disk, by correcting properly the ON period duty of a laser modulated signal in response to the radius direction of the optical disk. CONSTITUTION:An optical disk 1 is driven by a spindle motor 3 and rotated at a fixed angular speed. At the same time, a head access controller 8 drives an optical head moving motor 6 so that both an optical recording head 4 and an auxiliary magnetic field generator 5 are set at the designated recording track address. The duty ratio between the ON and OFF periods of the laser light obtained at the designated track address is set to a pulse duty modulator 7 by the controller 8. Thus the disk 1 is set in a stand-by state, and the modulated signal supplied synchronously with the readout of the designated address is modulated by the modulator 7. Then the modulated signal controls the laser diode within the head 4. |
