Abstract: An image sensor may include a symmetrical imaging pixel with a floating diffusion region. The floating diffusion region may be formed in the center of the imaging pixel. A shallow p-well may be formed around the floating diffusion region. A transfer gate configured to transfer charge from a photodiode to the floating diffusion region may be ring-shaped with an opening that overlaps the floating diffusion region. Isolation regions including deep trench isolation and a p-well may surround the photodiode of the imaging pixel. A p-stripe may couple the shallow p-well around the floating diffusion region to the isolation regions. The floating diffusion regions of neighboring pixels may be coupled together with additional conductive layers to implement shared configurations.

Abstract: A pixel array within an integrated-circuit image sensor is exposed to light representative of a scene during a first frame interval and then oversampled a first number of times within the first frame interval to generate a corresponding first number of frames of image data from which a first output image may be constructed. One or more of the first number of frames of image data are evaluated to determine whether a range of luminances in the scene warrants adjustment of an oversampling factor from the first number to a second number, if so, the oversampling factor is adjusted such that the pixel array is oversampled the second number of times within a second frame interval to generate a corresponding second number of frames of image data from which a second output image may be constructed.

Abstract: Signals representative of total photocharge integrated within respective image-sensor pixels are read out of the pixels after a first exposure interval that constitutes a first fraction of a frame interval. Signals in excess of a threshold level are read out of the pixels after an ensuing second exposure interval that constitutes a second fraction of the frame interval, leaving residual photocharge within the pixels. After a third exposure interval that constitutes a third fraction of the frame interval, signals representative of a combination of at least the residual photocharge and photocharge integrated within the pixels during the third exposure interval are read out of the pixels.

Abstract: A pixel within a pixel array of an integrated-circuit image sensor outputs an analog signal representative of accumulated photocharge. First and second analog-to-digital conversions of the analog signal are initiated while the pixel is outputting the analog signal, the first analog-to-digital conversion corresponding to a low-light range of photocharge accumulation within the pixel and the second analog-to-digital conversion corresponding to a brighter-light range of photocharge accumulation within the pixel.

Abstract: An image sensor pixel may include a photodiode, a floating diffusion, and a transfer gate. A buried channel may be formed under the transfer gate. The buried channel may extend from the floating diffusion to overlap a portion of the transfer gate without extending completely beneath the transfer gate or reaching the photodiode. The buried channel may provide a path for antiblooming current from the photodiode to reach the floating diffusion, while allowing for the transfer gate off voltage to remain high enough to prevent transfer gate dark current from flowing into the photodiode.

Abstract: Multiple image data subframes corresponding to respective portions of an exposure interval are generated within a sensor device of an image system. Depending on whether the exposure interval exceeds one or more exposure time thresholds, data representative multiple image data subframes are output from the image sensor device in one of at least two formats, including a first format in which each of the subframes of image data is output in its entirety, and a second format in which a logical combination of at least two of the subframes of image data is output instead of the at least two of the subframes of image data such that the total volume of image data output from the image sensor device is reduced relative to the first format.

Abstract: Photocharge is integrated within a first plurality of pixels of an integrated-circuit image sensor during a first exposure interval. A read-out signal is output from each pixel of the first plurality of pixels upon conclusion of the first exposure interval, each read-out signal indicating a respective level of photocharge integrated within the corresponding pixel during the first exposure interval. Photocharge is also integrated within a second plurality of pixels during a second exposure interval that transpires concurrently with the first exposure interval and has a duration not more than half the duration of the first exposure interval. A read-out signal is output from each pixel of the second plurality of pixels at least twice with respect to the second exposure interval, with each such read-out signal indicating a respective level of photocharge integrated within the corresponding pixel during at least a portion of the second exposure interval.

Abstract: In an integrated-circuit image sensor having a pixel array, first and second control pulses that enable photocharge transfer from respective first and second photosensitive elements to a shared floating diffusion node are staggered in time such that capacitive feedthrough to the shared floating diffusion node from a trailing edge of the first control pulse is counteracted by capacitive feedthrough to the shared floating diffusion node from a leading edge of the second control pulse.

Abstract: An image sensor pixel may include a photodiode, a floating diffusion, and a transfer gate. A buried channel may be formed under the transfer gate. The buried channel may extend from the floating diffusion to overlap a portion of the transfer gate without extending completely beneath the transfer gate or reaching the photodiode. The buried channel may provide a path for antiblooming current from the photodiode to reach the floating diffusion, while allowing for the transfer gate off voltage to remain high enough to prevent transfer gate dark current from flowing into the photodiode.

Abstract: An image sensor may include a symmetrical imaging pixel with a floating diffusion region. The floating diffusion region may be formed in the center of the imaging pixel. A shallow p-well may be formed around the floating diffusion region. A transfer gate configured to transfer charge from a photodiode to the floating diffusion region may be ring-shaped with an opening that overlaps the floating diffusion region. Isolation regions including deep trench isolation and a p-well may surround the photodiode of the imaging pixel. A p-stripe may couple the shallow p-well around the floating diffusion region to the isolation regions. The floating diffusion regions of neighboring pixels may be coupled together with additional conductive layers to implement shared configurations.

Abstract: An image sensor architecture with multi-bit sampling is implemented within an image sensor system. A pixel signal produced in response to light incident upon a photosensitive element is converted to a multiple-bit digital value representative of the pixel signal. If the pixel signal exceeds a sampling threshold, the photosensitive element is reset. During an image capture period, digital values associated with pixel signals that exceed a sampling threshold are accumulated into image data.

Abstract: In a pixel array within an integrated-circuit image sensor, each of a plurality of pixels is evaluated to determine whether charge integrated within the pixel in response to incident light exceeds a first threshold. N-bit digital samples corresponding to the charge integrated within at least a subset of the plurality of pixels are generated, and then applied to a lookup table to retrieve respective M-bit digital values (M being less than N), wherein a stepwise range of charge integration levels represented by possible states of the M-bit digital values extends upward from a starting charge integration level that is determined based on the first threshold.

Abstract: A sequence of control voltage levels are applied to a control signal line capacitively coupled to a floating diffusion node of a pixel to sequentially adjust a voltage level of the floating diffusion node. A pixel output signal representative of the voltage level of the floating diffusion node is compared with a reference voltage to identify a first control voltage level of the sequence of control voltage levels for which the voltage level of the floating diffusion node exceeds the reference voltage.

Abstract: A pixel circuit within an integrated-circuit image sensor includes a photodiode having a pinning layer of a first conductivity type, a floating diffusion node and a transfer gate disposed between the photodiode and the floating diffusion node. A first control input is coupled to the transfer gate, and a second control input is coupled to the pinning layer of the photodiode to enable the depletion potential of the photodiode to be raised and lowered.

Abstract: In a pixel array within an integrated-circuit image sensor, each of a plurality of pixels is evaluated to determine whether charge integrated within the pixel in response to incident light exceeds a first threshold. N-bit digital samples corresponding to the charge integrated within at least a subset of the plurality of pixels are generated, and then applied to a lookup table to retrieve respective M-bit digital values (M being less than N), wherein a stepwise range of charge integration levels represented by possible states of the M-bit digital values extends upward from a starting charge integration level that is determined based on the first threshold.

Abstract: An image sensor architecture with multi-bit sampling is implemented within an image sensor system. A pixel signal produced in response to light incident upon a photosensitive element is converted to a multiple-bit digital value representative of the pixel signal. If the pixel signal exceeds a sampling threshold, the photosensitive element is reset. During an image capture period, digital values associated with pixel signals that exceed a sampling threshold are accumulated into image data.

Abstract: In a pixel array within an integrated-circuit image sensor, each of a plurality of pixels is evaluated to determine whether charge integrated within the pixel in response to incident light exceeds a first threshold. N-bit digital samples corresponding to the charge integrated within at least a subset of the plurality of pixels are generated, and then applied to a lookup table to retrieve respective M-bit digital values (M being less than N), wherein a stepwise range of charge integration levels represented by possible states of the M-bit digital values extends upward from a starting charge integration level that is determined based on the first threshold.

Abstract: Pixels within an image sensor pixel array are sampled by corresponding conditional read circuitry. A zero pixel value is outputted for each pixel associated with a sample less than a conversion threshold, and a saturated pixel value is outputted for each pixel associated with a sample greater than or equal to a saturation threshold. Samples greater than or equal to the conversion threshold and less than the saturation threshold are converted by an ADC, and a converted pixel value is output for each associated above threshold pixel. The ADC (along with any corresponding amplifiers) are powered on for a variable period depending on the number of pixels needing conversion during the conversion of such samples during a read period, and are powered off for the remainder of the read period.

Abstract: Signals representative of total photocharge integrated within respective image-sensor pixels are read out of the pixels after a first exposure interval that constitutes a first fraction of a frame interval. Signals in excess of a threshold level are read out of the pixels after an ensuing second exposure interval that constitutes a second fraction of the frame interval, leaving residual photocharge within the pixels. After a third exposure interval that constitutes a third fraction of the frame interval, signals representative of a combination of at least the residual photocharge and photocharge integrated within the pixels during the third exposure interval are read out of the pixels.

Abstract: In a pixel array within an integrated-circuit image sensor, each of a plurality of pixels is evaluated to determine whether charge integrated within the pixel in response to incident light exceeds a first threshold. N-bit digital samples corresponding to the charge integrated within at least a subset of the plurality of pixels are generated, and then applied to a lookup table to retrieve respective M-bit digital values (M being less than N), wherein a stepwise range of charge integration levels represented by possible states of the M-bit digital values extends upward from a starting charge integration level that is determined based on the first threshold.