| 摘要 |
PURPOSE:To enable to use a laser diode irrespective of the polarity of the diode by separating the light output control circuit of the diode and the diode in a DC manner. CONSTITUTION:When a laser diode 29 does not produce a light output of an OP amplifier 11 becomes high, and transistors 6, 10 are turned ON. The oscilla tion output of an oscillator 4 is increased, rectified and smoothed by diodes 27a, 27b and capacitor 28 to turn ON the diode 29. A photocurrent starts flowing to the diode 31, and the -input terminal of the amplifier 11 rises. The waveform of the collector of the transistor 6 is integrated and supplied as a DC to the oscillator 4, but this voltage is reduced from the previous state to decrease the current flowing to the diode 31. When the voltage of the -input terminal of the amplifier 11 rises, the output voltage of the terminal 3 decreases to control the current of the diode 31. |
