| 摘要 |
PURPOSE:To record and reproduce information in accurate timing by making the intensity of laser light at the rise part of a laser light pulse higher than at a following part and making the intensity of the laser light immediately after the fall of the pulse lower than the intensity of stationary wave. CONSTITUTION:The output pulse of a buffer amplifier 104 is differentiated by a differentiation circuit consisting of a capacitor 25 and a resistance 26. Therefore, a small positive pulse is inputted in a transistor TR 24 at the rise of a recording signal 101 and a small negative pulse is inputted there at the fall of the recording signal 101. Therefore, a bias current from the TR 24 is changed so that the intensity of irradiation to a recording medium 11 may be increased at a leading edge part which is irradiated with recording light and the intensity of the irradiating light may be decreased immediately after completing the irradiation of the recording light. Thus, the shortage of the rise of a temperature at the leading edge of a bit is compensated and trailing at the trailing edge part of the bit is eliminated, so that the bit having the accurate timing is formed at the leading edge part and the trailing edge part. |
