| 摘要 |
PURPOSE:To remove a crosstalk signal from the photocurrent signal of a selected photodetecting element by providing the 1st and the 2nd sample holding (SH) means, the 1st and the 2nd switching arrays, and a differential signal amplifying means. CONSTITUTION:When photodetecting elements Ci1, Ci2,...Cin connected to common electrodes Bi are selected by the output of a shift register 301, light signal currents SS1-SSn flow to their individual electrodes S1, S2,...Sn flow to their individual electrodes S1, S2,...Sn and crosstalk currents also flow through photodetecting elements connected to unselected common electrode. Those currents are amplified 303 after the applied voltage response times of the photodetecting elements and stored in the 1st SH means 304. Then, when all common electrodes B1-Bn are selected only, the crosstalk current flows. This is amplified 303 a specific time later and stored in the 2nd SH means 305. Then, the 1st and the 2nd switching arrays 306 and 307 are switched at the timing of timing pulse signals SSW1-SSWn to lead out signals differentially by the differential signal amplifying means 308.
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