| 摘要 |
PURPOSE:To form such pits that an excellent reproduction output is obtained, and eliminate the risk of destruction of record due to an irradiating readout light beam by irradiating a recording medium which has high heat conductivity with proper light pulses. CONSTITUTION:The optical recording medium in use has heat diffusivity of >=5mum<2>/mus in the medium surface and recording is carried out while the light intensity of laser light pulses is made larger at the leading edge part than at the trailing edge part. A differential amplifier 20 in a laser driving circuit supplies differential signals to TRs 21 and 22 according to an input signal. A capacitor 38 applies only the variation component of voltage pulses of a variable resistor 26 to a TR23. Then when the signal applied to the TR22 rises and falls, a positive and a negative edge pulse are applied to the base of the TR23 and a laser 3 emits light with large power at the leading edge part of a pulse supplied to the laser 3. When the pulse to the TR22 rises, on the other hand, there is no influence upon the current supplied to the laser 3, so the light power becomes larger at the leading edge of the laser light pulse than at the trailing edge part. |
