An analog-to-digital converter includes a generator, a comparator, and a counter. The generator generates a reference signal whose voltage changes with respect to time. The voltage of the reference signal changes with a constant slope in a predetermined first period since the voltage starts changing. The slope of the voltage becomes steeper with respect to time in a second period after the first period. The comparator compares the reference signal and a voltage output from outside, and outputs a comparison result. The counter counts at a predetermined first cycle since the voltage of the reference signal starts changing until the comparison result is inverted.

An analog-to-digital converter includes a generator, a comparator, and a counter. The generator generates a reference signal whose voltage changes with respect to time. The voltage of the reference signal changes with a constant slope in a predetermined first period since the voltage starts changing. The slope of the voltage becomes steeper with respect to time in a second period after the first period. The comparator compares the reference signal and a voltage output from outside, and outputs a comparison result. The counter counts at a predetermined first cycle since the voltage of the reference signal starts changing until the comparison result is inverted.

An image sensor includes: a pixel substrate that includes a plurality of pixels each having a photoelectric conversion unit that generates an electric charge through photoelectric conversion executed on light having entered therein and an output unit that generates a signal based upon the electric charge and outputs the signal; and an arithmetic operation substrate that is laminated on the pixel substrate and includes an operation unit that generates a corrected signal by using a reset signal generated after the electric charge in the output unit is reset and a photoelectric conversion signal generated based upon an electric charge generated in the photoelectric conversion unit and executes an arithmetic operation by using corrected signals each generated in correspondence to one of the pixels.

An image pickup element includes: a semiconductor substrate including a photoelectric conversion section for each pixel; a pixel separation groove provided in the semiconductor substrate; and a fixed charge film provided on a light-receiving surface side of the semiconductor substrate, wherein the fixed charge film includes a first insulating film and a second insulating film, the first insulating film being provided contiguously from the light-receiving surface to a wall surface and a bottom surface of the pixel separation groove, and the second insulating film being provided on a part of the first insulating film, the part corresponding to at least the light-receiving surface.

Various implementations disclosed herein include devices, systems, and methods that buffer events in device memory during synchronous readout of a plurality of frames by a sensor. Various implementations disclosed herein include devices, systems, and methods that disable a sensor communication link until the buffered events are sufficient for transmission by the sensor. In some implementations, the sensor using a synchronous readout may select a readout mode for one or more frames based on how many of the pixels are detecting events. In some implementations, a first mode that reads out only data for a low percentage of pixels that have events uses the device memory and a second mode bypasses the device memory based on accumulation criteria such as high percentage of pixels detecting events. In the second mode, less data per pixel may be readout.

Imaging devices are disclosed. In one example, an imaging device includes a photoelectric conversion unit with plural photoelectric conversion elements, a detector that outputs a detection signal indicating whether or not an amount of change in the electric signal of each of the photoelectric conversion elements exceeds a predetermined threshold value, a pixel signal generation unit that generates a pixel signal on the basis of the electric signal, a transfer controller that controls transfer of the electric signal to the pixel signal generation unit, and an analog-to-digital converter that converts the pixel signal into a digital signal. The low-potential-side reference potentials of the photoelectric conversion unit, the detector, the pixel signal generation unit, and the analog-to-digital converter, and the off-potential of the transfer controller include three or more potentials having different potential levels.

A semiconductor device according to an embodiment includes a plurality of element arrays, a signal-processing circuit, and a comparison-voltage generation circuit. Each element array is selectively connected to a vertical signal line and includes an amplification transistor configured to output a first analog signal on the basis of an input analog voltage and an actual value of variation of a characteristic value of each element array included in the plurality of element arrays. The comparison-voltage generation circuit is configured to output a gradually increasing or gradually decreasing comparison voltage. The signal-processing circuit includes a storage circuit and is configured to compare the first analog signal with the comparison voltage and store a timing at which the comparison voltage and a value of a second analog signal generated by adding a predetermined absolute value to the first analog signal match each other onto the storage circuit.

An abnormal-pixel detecting device includes an image sensor and an image processor. The image sensor is configured to capture an image of a subject. The image processor is configured to calculate: a ratio between a first plurality of pixel values captured by the image sensor and a second plurality of pixel values whose reference position is shifted relative to the first plurality of pixel values in a main scanning direction to obtain a third plurality of pixel values; and detect an abnormal pixel in the third plurality of pixel values.

Methods and apparatus for an imaging sensor having background subtraction including integrating photocurrent on a first capacitor, and, after a voltage on the first capacitor reaches a threshold, directing the photocurrent to a second capacitor. The first capacitor can be reset. This can be repeated a given number of times until a value on the second capacitor is read out.

An image sensor may include a pixel array a pixel array including an active pixel and an optical black pixel, the active pixel configured to generate a first pixel signal, and the optical black pixel configured to generate a second pixel signal, a first biasing circuit configured to bias the first pixel signal based on a first bias voltage, a first analog-to-digital converter configured to convert the biased first pixel signal into a first digital signal, a second biasing circuit configured to bias the second pixel signal based on a second bias voltage, and a second analog-to-digital converter configured to convert the biased second pixel signal into a second digital signal, the second digital signal configured to generate smaller random noise than the first analog-to-digital converter.