| 摘要 |
PROBLEM TO BE SOLVED: To provide a photodetector that can stabilize frequency characteristic of an amplifier for light reception and, in addition, can maintain detection accuracy for light quantities. SOLUTION: A control unit 4a detects value of the output voltage VOUT of this photodetector and, when the voltage VOUT becomes a saturation voltage level Vsat or higher, the unit 4a closes several switches by switching an electronic shutter 5a. Consequently, the quantity of incident light to a photodiode 1a decreases and the level of the output voltage VOUT falls and returns to a linear region. When the quantity Pr2 of the incident light to the photodiode 1a decreases and the level of the output voltage VOUT falls to the vicinity of a reference voltage Vs, the control unit 4a switches the electronic shutter 5a so as to open several closed switches in the shutter 5a. COPYRIGHT: (C)2003,JPO
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