| 摘要 |
PURPOSE:To reduce the overshoot and ringing of a current driving each laser element, by constituting each driving circuit of a differential amplifier circuit which sets each laser element as a load on one side, and setting the characteristic of a damping adjuster at a prescribed characteristic. CONSTITUTION:The emitters of transistors 31 and 32 are connected mutually, and furthermore, they constitute a differential amplifier circuit type switching circuit by being connected to a constant current source 3, and one end of a resistor 34 is connected to the base of the transistor 31, and one end of a resistor 35 to that of the transistor 35, respectively. The other ends of the resistors 34 and 35 from the control signal input terminals 37 and 38 of the titled pulse driving circuit 36, respectively. A resistor 39 is connected between the bases of the transistors 31 and 32, and the resistors 34, 35, and 39 constitute the damping adjuster 41 of a four terminal circuit network. And the prescribed characteristic is attached on the damping adjuster 41. In such a way, it is possible to reduce the overshoot and ringing of the current to drive each laser element. |
