Abstract: An arithmetic counter circuit for high performance CMOS image sensors includes a plurality of flip-flops of a plurality of counter stages and a plurality of multiplexers of the plurality of counter stages being coupled to the plurality of flip-flops. Each of the plurality of multiplexers coupled to receive control signals including at least one of a toggle signal, a keep signal, a shift enable signal, or a mode signal. The control signals select the output of each of the plurality of multiplexers. Each of the plurality of flip-flops is coupled to be in one of a toggle state, a keep state, a reset state or a set state based on inputs received from the plurality of multiplexers. Other embodiments are described.

Abstract: A CMOS image sensor includes an image pixel array, a dark pixel array, data bit liens, reference bit lines, a driver, comparators, and analog-to-digital converter (“ADC”) circuits. The image pixel array generates analog image signals in response to incident light. The dark pixel array generates analog black reference signals for analog black level calibration of the analog image signals. In one embodiment, the data bit lines each coupled to a different column of image pixels of the image pixel array and the reference bit lines each coupled to a different column of black reference pixels within the dark pixel array. The driver is coupled to the reference bit lines to drive an analog black reference signal. The comparators each couple to one of the data bit lines and each coupled to an output of the driver and offset the analog image signals with the analog black reference signals in an analog domain. The ADC circuits each coupled to an output of a comparator.

Abstract: This is generally directed to systems and methods for reading optical black pixel cells. For example, in some embodiments, the columns of a pixel array can be shunted together during an optical black pixel readout phase of the imaging system. This may, for example, help improve correction of column fixed pattern noise or other noise. In some embodiments, the column may be shunted together during the optical black pixel readout phase of the imaging system and not shunted during other phases of the imaging system (e.g., when reading values from active pixel cells, barrier pixel cells, etc). In some embodiments, circuitry for providing the column shunting can be implemented as an independent block of the imaging system. In other embodiments, this circuitry can be implemented within other blocks of the imaging system. As an illustration, the shunting circuitry can be implemented within a VLN block of the imaging system.

Abstract: A method of implementing high dynamic range bin algorithm in an image sensor including a pixel array with a first super row having a first integration time and a second super row having a second integration time is described. The method starts by reading out image data from the first super row into a counter. Image data from the first super row is multiplied by a factor to obtain multiplied data. The factor is a ratio between the first and the second integration times. The multiplied data is then compared with a predetermined data. The image data from the second super row is readout into the counter. If the multiplied data is larger than the predetermined data, the multiplied data from the first super row is stored in the counter. If not, the image data from the second super row is stored. Other embodiments are also described.

Abstract: A system, method and apparatus implementing a multiple-row concurrent readout scheme for high-speed CMOS image sensor with backside illumination are described herein. In one embodiment, the method of operating an image sensor starts acquiring image data within a color pixel array and the image data from a first set of multiple rows in the color pixel array is then concurrently readout. Concurrently reading out the image data from the first set of multiple rows includes concurrently selecting a first portion of the image data from the first set by first readout circuitry and a second portion of the image data from the first set by second readout circuitry. The first and second portions of the image data from the first set are different and the first and second readout circuitries are also different. Other embodiments are also described.

Abstract: An arithmetic counter circuit for high performance CMOS image sensors includes a plurality of flip-flops of a plurality of counter stages and a plurality of multiplexers of the plurality of counter stages being coupled to the plurality of flip-flops. Each of the plurality of multiplexers coupled to receive control signals including at least one of a toggle signal, a keep signal, a shift enable signal, or a mode signal. The control signals select the output of each of the plurality of multiplexers. Each of the plurality of flip-flops is coupled to be in one of a toggle state, a keep state, a reset state or a set state based on inputs received from the plurality of multiplexers. Other embodiments are described.

Abstract: A CMOS image sensor includes an image pixel array, a dark pixel array, data bit liens, reference bit lines, a driver, comparators, and analog-to-digital converter (“ADC”) circuits. The image pixel array generates analog image signals in response to incident light. The dark pixel array generates analog black reference signals for analog black level calibration of the analog image signals. In one embodiment, the data bit lines each coupled to a different column of image pixels of the image pixel array and the reference bit lines each coupled to a different column of black reference pixels within the dark pixel array. The driver is coupled to the reference bit lines to drive an analog black reference signal. The comparators each couple to one of the data bit lines and each coupled to an output of the driver and offset the analog image signals with the analog black reference signals in an analog domain. The ADC circuits each coupled to an output of a comparator.

Abstract: An imaging system may include an image sensor array formed from imaging pixels with feedback loops. Each imaging pixel may include an amplifier transistor that is controlled by a voltage on a floating diffusion node and may include a feedback transistor connected between the floating diffusion node and column readout circuitry. The amplifier transistor, together with a current source in the image sensor array, may form a common-source amplifier that inversely amplifies the voltage on the floating diffusion node and provides control signals to the feedback transistor. The common-source amplifier and the feedback transistor may create a feedback loop during image readout operations and during image reset operations that clamps the voltage on the floating diffusion node.

Abstract: Systems and methods for providing one or more reference currents with respective negative temperature coefficients are provided. A first voltage is divided to provide a divided voltage, which is compared to a reference voltage (e.g., a bandgap reference voltage) to provide a control voltage. The first voltage and the one or more reference currents are based on the control voltage.

Abstract: A pixel circuit having improved charge transfer including an amplifier having an input node electrically connected to a charge storage node of the pixel circuit, and a negative feedback control loop having a capacitance element electrically connected between the input node and an output node of said amplifier.

Abstract: A system for controlling power applied to pixels in an imager. A first switch coupling the internal power node of the pixels to the power supply of the imager. A second switch coupling the internal power node of the pixels to a ground potential or low potential. The first and second switches are controlled complimentary to each other during integration and readout of the pixels. A third switch providing a high impedance mode where the internal power node and n+ guard ring are isolated from the operating and ground potentials.

Abstract: A CMOS image sensor includes an image pixel array, a dark pixel array, data bit liens, reference bit lines, a driver, comparators, and analog-to-digital converter (“ADC”) circuits. The image pixel array generates analog image signals in response to incident light. The dark pixel array generates analog black reference signals for analog black level calibration of the analog image signals. In one embodiment, the data bit lines each coupled to a different column of image pixels of the image pixel array and the reference bit lines each coupled to a different column of black reference pixels within the dark pixel array. The driver is coupled to the reference bit lines to drive an analog black reference signal. The comparators each couple to one of the data bit lines and each coupled to an output of the driver and offset the analog image signals with the analog black reference signals in an analog domain. The ADC circuits each coupled to an output of a comparator.

Abstract: A method of one aspect includes reading a reset level of an active pixel, and concurrently, reading a reset level of a reference pixel. The method also includes reading an image signal level of the active pixel, and concurrently, reading an image signal level of the reference pixel. A reduced noise image signal level of the active pixel is generated based on the reset levels and the image signal levels of the active and reference pixels. Other methods are disclosed as well as apparatus and systems.

Abstract: An imaging system may include an image sensor array formed from imaging pixels with feedback loops. Each imaging pixel may include an amplifier transistor that is controlled by a voltage on a floating diffusion node and may include a feedback transistor connected between the floating diffusion node and column readout circuitry. The amplifier transistor, together with a current source in the image sensor array, may form a common-source amplifier that inversely amplifies the voltage on the floating diffusion node and provides control signals to the feedback transistor. The common-source amplifier and the feedback transistor may create a feedback loop during image readout operations and during image reset operations that clamps the voltage on the floating diffusion node.

Abstract: An image sensor includes a plurality of pixel cells organized into rows and columns of a pixel array. A bit line is coupled to each of the pixel cells within a line of the pixel array. Readout circuitry is coupled to the bit line to readout the image data from the pixel cells within the line. The readout circuitry includes a line amplifier coupled to the bit line to amplify the image data and first and second sample and convert circuits coupled in parallel to an output of the line amplifier to reciprocally and contemporaneously sample the image data and convert the image data from analog values to digital values.

Abstract: A VLN biasing scheme implemented in an image sensor with top/bottom readout. A first and second current sink coupled to the top of a first column of pixels and a second column of pixels respectively. A third and fourth current sink coupled to the bottom of a first column of pixels and a second column of pixels respectively. During column readout, each current sink sinks an equal amount of current.

Abstract: This is generally directed to systems and methods for reading optical black pixel cells. For example, in some embodiments, the columns of a pixel array can be shunted together during an optical black pixel readout phase of the imaging system. This may, for example, help improve correction of column fixed pattern noise or other noise. In some embodiments, the column may be shunted together during the optical black pixel readout phase of the imaging system and not shunted during other phases of the imaging system (e.g., when reading values from active pixel cells, barrier pixel cells, etc). In some embodiments, circuitry for providing the column shunting can be implemented as an independent block of the imaging system. In other embodiments, this circuitry can be implemented within other blocks of the imaging system. As an illustration, the shunting circuitry can be implemented within a VLN block of the imaging system.

Abstract: Methods and apparatuses providing pixel-wise noise correction using pixels to provide reference values during pixel readout operations.

Abstract: An imaging device and method for operating the device. The imaging device comprises a pixel array that comprises a plurality of imaging pixels and dark reference pixels arranged in columns and rows. The dark reference pixels produce a noise signal that is subtracted from a pixel signal produced by the imaging pixels to correct row noise. In addition, the imaging device may comprise a hot pixel filtering circuit that blocks the output from hot pixels.

Abstract: Methods and apparatuses for row-wise dark level non-uniformity compensation of imaging sensor pixel signals. A column dependent dark reference value is determined as one of a linear and parabolic function of signal values from two areas of dark reference pixels and a column location and then used for dark level non-uniformity compensation of signal values from imaging pixels.