| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image sensor capable of holding data for at least one frame period and of conducting a difference operation with a small number of elements. <P>SOLUTION: Photosensors are provided to a plurality of pixels arranged in a matrix. Each pixel accumulates electric charge in a data holding portion for one frame period or longer. An output of the photosensor is changed in accordance with the electric charge accumulated in the data holding portion. As a writing switch element for the data holding portion, a transistor with small leakage current (sufficiently smaller than 1×10<SP POS="POST">-14</SP>A) is used. As the transistor with small leakage current, there is a transistor having a channel formed in an oxide semiconductor layer. <P>COPYRIGHT: (C)2013,JPO&INPIT |
