| 摘要 |
PURPOSE:To suppress useless power consumption at the time of reproduction by interrupting a current from a current source in a driving means driving a semiconductor laser oscillator. CONSTITUTION:By a laser driver 17, a driving current according to an output signal from a sample-hold circuit and a recording data signal, a control signal and an input voltage for the current source supplied from a control circuit is outputted. The current by power source voltage VCC flows through a laser diode 4, a transistor 21 and a resistor R1 at a reproducing time. At this time, by the transistor 21, the driving current outputted to the diode 4 is revised according to an error signal as the output signal from the sample-hold circuit to control recording light quantity. Further, the transistor 25 is turned on by the control signal from the control circuit, and the supply of the input voltage to the transistor 24 is interrupted. Thus, the current flowing through the transistor 23 becomes zero. Further, the current flowing through the transistor 22 becomes zero also since no recording data signal is supplied. |
