Abstract: An imaging system that has an image processing function and is capable of generating an interpolation image is provided. The imaging system has an additional function such as image processing and can generate an interpolation image by using image data output from an imaging device. The imaging device can perform filter processing in parallel during a light exposure period, and thus can perform a large amount of arithmetic operation and generate a high-quality interpolation image. The number of arithmetic operations can be further increased particularly during image capturing in a dark place, which requires a long exposure time. Accordingly, the frame rate can be substantially increased, and high-quality moving image data can be generated.

Abstract: An imaging device capable of executing image processing is provided. Analog data (image data) acquired through an imaging operation is retained in a pixel, and data obtained by multiplying the analog data by a given weight coefficient in the pixel can be extracted. The data is taken into a neural network or the like, whereby processing such as image recognition can be performed. Since an enormous amount of image data can be retained in pixels in an analog data state, processing can be performed efficiently.

Abstract: A semiconductor device capable of stable operation with low power consumption is provided. A logic circuit having a circuit configuration using a transistor including an oxide semiconductor in a channel formation region is included. The logic circuit is a two-input/two-output two-wire logic circuit. Transistors included in the logic circuit each include a gate and a back gate. An input terminal is electrically connected to one of a gate and a back gate of a transistor electrically connected to a wiring for supplying a high power supply potential. An output terminal is connected to the other of the gate and the back gate of the transistor electrically connected to the wiring for supplying a high power supply potential. An output terminal is electrically connected to one of a source and a drain of a transistor electrically connected to a wiring for supplying a low power supply potential.

Abstract: An imaging device having a motion detecting function and an image processing function is provided. The imaging device can detect a difference between a reference frame image and a comparative frame image, and can switch from a motion detecting mode to a normal image capturing mode when a significant difference is detected. A low-frame-rate operation in the motion detecting mode can reduce power consumption. Moreover, the imaging device has an image recognition function in combination with the motion detecting function, so that switching from the motion detecting mode to the normal image capturing mode can be performed when a particular image is recognized.

Abstract: An imaging device with low power consumption is provided. A pixel includes a first circuit and a second circuit. The first circuit can generate imaging data and retain difference data that is a difference between the imaging data and data obtained in an initial frame. The second circuit includes a circuit that compares the difference data and a voltage range set arbitrarily. The second circuit supplies a reading signal based on the comparison result. With the use of the structure, reading from the pixel is not performed when it is determined that the difference data is within the set voltage range and reading from the pixel can be performed when it is determined that the difference data is outside the voltage range.

Abstract: An inspection device having a plurality of functions is achieved. The performance of an inspection device is improved. A structure of an inspection device is simplified. A structure of an imaging device is simplified. The inspection device includes a light source having a function of emitting infrared light, a light source having a function of emitting visible light, and an imaging portion which are provided over a substrate having flexibility, and inspects a fruit or vegetable. A first image based on light including reflected light of the infrared light, and a second image and a third image based on tight including reflected light of the visible light are captured by the imaging portion. The inspection device has a function of detecting one or more of the sugar content, the acidity, and a physiological disorder of a fruit or vegetable on the basis of the first image.

Abstract: An imaging device that can obtain imaging data corresponding to high-resolution images in a short period of time is provided. The imaging device includes a pixel including a photoelectric conversion element and n (n is an integer more than 2 inclusive) retention circuits. The photoelectric conversion element and the n retention circuits are stacked. One electrode of the photoelectric conversion element is electrically connected to the first to n-th retention circuits. The retention circuits include OS transistors with an extremely low off-state current feature, and can retain imaging data for a long time. In the first to n-th periods, the imaging device obtains the first to n-th imaging data and retains it in the first to n-th retention circuits. Then, the first to n-th imaging data retained in the first to n-th retention circuits are read out. The read imaging data is output outside the imaging data through AD conversion.

Abstract: An imaging device with a novel structure is provided. The imaging device includes an imaging region provided with a plurality of pixels. The plurality of pixels included in the imaging region include a first pixel and a second pixel. The imaging device has a function of selecting a first region or a second region. The first region includes the same number of pixels as the second region. The first region includes at least the first and second pixels. The second region includes at least the second pixel. The pixels included in the first region or the second region have a function of outputting imaging signals obtained by the pixels. The imaging device generates first image data by concurrently reading the imaging signals output from the pixels included in the first region and performing arithmetic operation on the signals.

Abstract: A novel authentication system is provided. In addition, a method for recording an unlocking history is provided. The authentication system includes an arithmetic device and an input/output device. The arithmetic device supplies first control data and second control data, and is supplied with a sensor signal. The input/output device includes an electric lock and a reading portion, and the electric lock is unlocked on the basis of the second control data. The reading portion is supplied with the first control data, supplies the sensor signal, and includes a light-emitting element and a pixel array. The light-emitting element emits light including infrared rays, the pixel array includes pixels, the pixels each include an imaging circuit and a photoelectric conversion element, the imaging circuit is electrically connected to the photoelectric conversion element, the imaging circuit includes a transistor, and the transistor includes an oxide semiconductor film.

Abstract: A highly functional imaging device is provided. A small imaging device is provided. An imaging device or the like capable of high-speed operation is provided. A highly reliable imaging device is provided. The imaging device includes a pixel array, and a light-blocking layer and a transparent conductive layer that are over the pixel array. The light-blocking layer includes a first region overlapping with a first pixel and a second region overlapping with a second pixel. The transparent conductive layer includes a region overlapping with the first region and a region overlapping with the second region. The transparent conductive layer has a light-transmitting property. The transparent conductive layer is electrically connected to the first region and the second region. First light enters the photoelectric conversion device included in the first pixel. Second light enters the photoelectric conversion device included in the second pixel.

Abstract: An imaging device with low power consumption is provided. A pixel includes a first circuit and a second circuit. The first circuit can generate imaging data and retain difference data that is a difference between the imaging data and data obtained in an initial frame. The second circuit includes a circuit that compares the difference data and a voltage range set arbitrarily. The second circuit supplies a reading signal based on the comparison result. With the use of the structure, reading from the pixel is not performed when it is determined that the difference data is within the set voltage range and reading from the pixel can be performed when it is determined that the difference data is outside the voltage range.

Abstract: An imaging device that can obtain imaging data corresponding to high-resolution images in a short period of time is provided. The imaging device includes a pixel including a photoelectric conversion element and n (n is an integer more than 2 inclusive) retention circuits. The photoelectric conversion element and the n retention circuits are stacked. One electrode of the photoelectric conversion element is electrically connected to the first to n-th retention circuits. The retention circuits include OS transistors with an extremely low off-state current feature, and can retain imaging data for a long time. In the first to n-th periods, the imaging device obtains the first to n-th imaging data and retains it in the first to n-th retention circuits. Then, the first to n-th imaging data retained in the first to n-th retention circuits are read out. The read imaging data is output outside the imaging data through AD conversion.

Abstract: A semiconductor device with low power consumption can be provided. The semiconductor device includes a differential circuit and a latch circuit, the differential circuit includes a transistor including an oxide semiconductor in a channel formation region, and the latch circuit includes a transistor including a single semiconductor or a compound semiconductor in a channel formation region. The differential circuit and the latch circuit include an overlap region.

Abstract: An imaging device that has an image processing function and is capable of operating at high speed is provided. The imaging device has an additional function such as image processing, image data obtained by an imaging operation is binarized in a pixel unit, and a product-sum operation is performed using the binarized data. A memory circuit is provided in the pixel unit and retains a weight coefficient used for the product-sum operation. Thus, an arithmetic operation can be performed without the weight coefficient read from the outside every time, whereby power consumption can be reduced. Furthermore, a pixel circuit, a memory circuit, and the like and a product-sum operation circuit and the like are stacked, so that the lengths of wirings between the circuits can be reduced, and high-speed operation with low power consumption can be performed.

Abstract: An imaging device that has an image processing function and is capable of a high-speed operation is provided. The imaging device has an additional function such as image processing, and can retain analog data obtained by an image capturing operation in pixels and extract data obtained by multiplying the analog data by a given weight coefficient. In the imaging device, the data is stored in a memory cell and pooling processing of data stored in a plurality of memory cells can be performed. The pixels are provided so as to have a region overlapping with at least one of the memory cells, a pooling processing circuit, and a reading circuit of the pixels; thus, an increase in the area of the imaging device can be inhibited even with an additional function.

Abstract: A semiconductor device capable of holding analog data is provided. Two holding circuits, two bootstrap circuits, and one source follower circuit are formed with use of four transistors and two capacitors. A memory node is provided in each of the two holding circuits; a data potential is written to one of the memory nodes and a reference potential is written to the other of the memory nodes. At the time of data reading, the potential of the one memory node is increased in one of the bootstrap circuits, and the potential of the other memory node is increased in the other of the bootstrap circuits. A potential difference between the two memory nodes is output by the source follower circuit. With use of the source follower circuit, the output impedance can be reduced.

Abstract: A multifunctional imaging device is provided. The imaging device includes first to fourth light-receiving elements and first and second functional layers. The first to fourth light-receiving elements are photoelectric conversion elements having sensitivity to light of different wavelengths from each other. The first and second functional layers each include first and second transistors. The first functional layer and the fourth to first light-receiving elements are stacked in this order over the second functional layer. In each of the first to fourth light-receiving elements, a first conductive layer, a first buffer layer, a photoelectric conversion layer, a second buffer layer, and a second conductive layer are stacked in this order. The photoelectric conversion layer includes an organic compound, and the first buffer layer and the second buffer layer each include a metal or an organic compound.

Abstract: An imaging device having an image processing function is provided. The imaging device includes a plurality of pixels. The pixel has a function of generating first data of an n-th frame by supplying a first weight to image data obtained in the n-th frame (n is an integer greater than or equal to 2). The pixel has a function of generating first data of an n?1-th frame by supplying a second weight to image data obtained in the n?1-th frame. The pixel has a function of generating second data by adding the first data of the n?1-th frame and the first data of the n-th frame.

Abstract: An imaging device having a function of processing an image is provided. The imaging device has an additional function such as image processing, can hold analog data obtained by an image capturing operation in a pixel, and can extract data obtained by multiplying the analog data by a predetermined weight coefficient. Difference data between adjacent light-receiving devices can be obtained in a pixel, and data on luminance gradient can be obtained. When the data is taken in a neural network or the like, inference of distance data or the like can be performed. Since enormous volume of image data in the state of analog data can be held in pixels, processing can be performed efficiently.

Abstract: A small-sized and highly functional imaging device is provided. The imaging device includes a photoelectric conversion device formed on a silicon substrate and a transistor including a channel formation region in a silicon epitaxial growth layer formed on the silicon substrate. The transistor provided in the epitaxial growth layer has favorable electrical characteristics, so that the imaging device with little noise can be formed. Since the transistor can be formed so as to have a region overlapping with the photoelectric conversion device, the imaging device can be downsized.