| 摘要 |
PURPOSE:To enable high speed, high precision, and high resolution by converting luminous level command signals into the currents in the forward direction so that the light receiving signals and the luminous level command signals may be equal, and controlling semiconductor lasers by the sum of the control currents of a light/electric negative return loop and the currents generated by conversion. CONSTITUTION:A current converter 20 outputs currents which are set in advance according to luminous level command signal Vs so that the light receiving signals and the luminous level command signals may be equal. That is, those are input into a luminous level command signal Vs differential amplifier 21, and are converter into the currents of Vs/R0 by a transistor 22 and a resistor R0. The currents Vs/R0+ADELTAV of the sum of the currents of this Vs/R0 and the output currents ADELTAV of the differential amplifier 9 become the currents in the forward direction of semiconductor lasers 3, and the semiconductor laser 3 outputs the light output P0 which is determined by the forward-direction currents Vs/R0+ADELTAV. A resistor 10 converters the control currents of a light/ electric negative return loop into voltages and detects them, and outputs those voltages. |
