Abstract: An imaging device includes a first semiconductor substrate and a second semiconductor substrate. The first semiconductor substrate includes a photoelectric conversion device and a first transistor. The second semiconductor substrate includes a second transistor, a third transistor, and a fourth transistor. One electrode of the photoelectric conversion device is electrically connected to one of a source and a drain of the first transistor. The other of the source and the drain of the first transistor is electrically connected to one of a source and a drain of the second transistor and a gate of the third transistor. One of a source and a drain of the third transistor is electrically connected to one of a source and a drain of the fourth transistor. The photoelectric conversion device and at least parts of the second transistor, the third transistor, and the fourth transistor overlap with each other.

Abstract: An imaging device capable of image processing is provided. The imaging device can retain analog data (image data) obtained by an image-capturing operation in a pixel and perform a product-sum operation of the analog data and a predetermined weight coefficient in the pixel to convert the data into binary data. When the binary data is taken in a neural network or the like, processing such as image recognition can be performed. Since enormous volumes of image data can be retained in pixels in the state of analog data, processing can be performed efficiently.