| 摘要 |
PURPOSE:To suppress the abnormal emission of semiconductor laser which is caused by momentary cutting off of its power source, by connecting a semiconductor switch to a space between an emitter and an earthing of the first transistor and preventing a charge of electricity to the first capacitor when the power source is cut off momentarily. CONSTITUTION:Electrical resistance 9 that is connected to the emitter of an NPN transistor 5 is connected to an earthing through diodes 14 and 15. Until a switch 13 is fitted again when semiconductor laser 1 stops operating, the diodes 14 and 15 stop operating if the potential of the emitter of the NPN transistor 5 comes to less than a prescribed voltage and further, the emitter comes to the state of high impedance. Then an electric current does not flow in the collector of the NPN transistor 5 and no electricity is charged to the capacitor 11. Accordingly, after fitting the switch 13, semiconductor laser 1 starts operating smoothly and is kept at a constant value without finding abnormal emission. |
