| 摘要 |
PURPOSE:To eliminate a restriction in a mounting surface by obviating a structure such as a light shielding plate used heretofore. CONSTITUTION:A delay circuit 2, a transition point detector 3, a comparator 5, an AND circuit 6, and a pair of transistors 7, 8 connected commonly with an emitter are provided. An input signal is applied to input terminals of the circuit 2 and the detector 3. An output signal of the comparator 5 and an output signal of the circuit 2 are applied as input signals to inputs of the circuit 6, a differential output signal of the circuit 6 is input to bases of the transistors 7, 8, and a semiconductor laser is connected to a collector of one of the transistors 7, 8. |
