| 摘要 |
PURPOSE:To obtain an image having no irregular concentration by detecting the quantity of light of a semiconductor laser to control a bias current and controlling a driving current. CONSTITUTION:The intensity of the output light of a semiconductor laser 1 is detected by a photodetector 9, and a detector 21 outputs an add/subtract signal of the application current of the laser 1 in response to the detection output. Bias current control means 22 made of bias current applying circuit 20 applies a bias voltage to the laser 1 in response to the output of the detector 21. A detector 24 outputs an add/subtract signal of the application current of the laser 1 in response to the output of the photodetector 9, and detects whether the output of the laser 1 is a predetermined value or not. Driving current control means 25 made of a driving circuit 23 applies a driving current to the laser 1 in response to the output of the detector 24. |
