| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device capable of suppressing a charge outflow from an accumulated charge retaining part as much as possible during a period from the end of an accumulation period up to reading of a final line in an image sensor for accumulating charges by a global shutter system.SOLUTION: In a CMOS sensor type image sensor in which a plurality of pixels is arranged like a matrix, a transistor, in which a channel formation region is formed by an oxide semiconductor, is used for each of a charge accumulation control transistor and a reset transistor which are in a pixel portion. After performing reset operation of a signal charge accumulation portion in all the pixels arranged like a matrix, charge accumulation operation by a photodiode is performed in all the pixels, and reading operation of signals from pixels is performed in each row. Accordingly, an image can be taken without distortion. |
