| 摘要 |
PURPOSE:To obtain a constant photo output by reducing the temperature dependency of the photo output by controlling the driving source of a photo semiconductor laser unit by detecting the state of the photo output. CONSTITUTION:Part of a laser beam emitted from photo semiconductor laser unit 1 is detected by photo detector 2 and output Vs equivalent to incident intensity is inputted to wind comparator 4. Circuit 4 makes a comparison between two kind of high and low reference voltages VUR and VLR and corresponding to three states of VLR>VS, VUR>VS>VLR and VS>VUR, switching circuit 5 sets integrator 6 in a charge state, charge stop state and discharge state so as to control the driving source of laser unit 1, thereby maintain output light in a stationary state under no influence of an ambient temperature. |
