| 摘要 |
PURPOSE:To obtain a device, which has few parts with reduced cost, by converting the result of the comparison operation of a micro-computer comparing and arithmetically operating an output signal from a photodetection means and a reference signal at every fixed time into an analog signal and causing currents propertional to the output signals to flow through a semiconductor laser. CONSTITUTION:An optical output from a semiconductor laser 100 is detected by a photodetection means 101, and an output signal from said means and a reference signal are compared with each other and arithmetically operated at every fixed time so that both signals are equalized by a micro-computer 102. The result of the comparison operation is converted into an analog signal by a digital-analog converter 103, and currents proportional to the analog signal are caused to flow through the semiconductor laser 100 by a semiconductor-laser drive circuit 104. Accordingly, the output from the semiconductor laser is controlled by using the microcomputer, thus decreasing the number of parts, then reducing cost. The microcomputer is also employed for other objects, thus further reducing cost. |
