| 摘要 |
PROBLEM TO BE SOLVED: To obviate a fixed-pattern noise with a simple circuit configuration. SOLUTION: Each pixel Qi consists of a photodiode PD, a pair of p-type MOS transistors M1, M2 to which gates G1, G2 are mutually connected respectively, and a switch SW. A constant current source 10 for supplying an initialization current Ires for initializing each pixel, and a control circuit 20 for controlling the switch SW provided in each pixel, are provided. When the control circuit 20 turns the switch SW on, a predetermined quantity of electric charges are accumulated in the photodiode PD so that an initialization gate voltage Vres necessary for supplying the initialization current Ires to the transistor M1 is obtained. When the control circuit 20 turns the switch SW off, a quantity of electric charges corresponding to received light among the accumulated electric charges, is discharged to vary a gate voltage Vg. The fluctuation quantity of the voltage Vg is detected as the fluctuation quantity of a signal current Isig in a signal processing circuit. COPYRIGHT: (C)2005,JPO&NCIPI
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