| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image sensor which can prevent impairment of S/N ratio incident to power supply voltage drop. <P>SOLUTION: In an image sensor, each pixel region includes a photodiode, a capacitor connected with one end of the photodiode at a first node and applying a potential to the first node, a reset transistor connected between the first node and a first power supply and resetting the potential at the first node to the potential of the first power supply, a comparator for comparing the potential at the first node with a reference voltage and outputting the comparison results to the gate of the reset transistor, a counter connected with the output end of the comparator and counting the number of times of inversion of the output signal from the comparator which takes place when the potential at the first node reaches the potential of the first power supply and outputting a digital value according to the number of times of inversion, and a select transistor connected between the output of the counter and one of vertical signal lines and provided with a gate connected with one of row select lines. <P>COPYRIGHT: (C)2010,JPO&INPIT |
