Abstract: Image sensor systems are disclosed that allow for charge transfer between pixels of a group included in a pixel array with a single digital readout of the accumulated charge from the group. Each of the pixels within a given group includes a photodetector. One or more pump gates are arranged between adjacent pixels of the given group to allow charge to be pumped from one pixel to the next in a serial fashion within the group. A readout circuit that includes at least a transfer gate and a capacitor may be coupled to a final pixel of the group to receive the accumulated charge and generate a photodetector signal (based on the accumulated charge) that can be amplified via a source follower component and ultimately read out to a column amplifier.

Abstract: Examples include an image sensor comprising a pixel array having at least one column of addressable pixel sensors, and a column amplifier coupled to the at least one column of addressable pixel sensors, the column amplifier comprising a transistor bank including a plurality of transistors, and mode select circuitry coupled to the transistor bank and configured to establish one or more connections among the plurality of transistors to configure the column amplifier to operate in one of a differential mode of operation and a single-ended mode of operation.

Abstract: Structures are disclosed for a binned set of two or more pixels of a pixel array that share a same readout circuit. The binned pixel design provides space-saving benefits on the chip and also improves the overall image quality. According to some embodiments, each of the binned pixels includes a photodetector and its own transfer gate. The readout circuit is coupled to the transfer gates of each of the binned pixels and includes its own second transfer gate that separates the pixels from a gain mode select block. The gain mode select block may include capacitors of different sizes and one or more switches to control which capacitors are to receive the charge from any one of the binned pixels. The readout circuit may also include a potential barrier (such as a diode), which allows for pumping charge onto the one or more capacitors of the gain mode select block.

Abstract: Image sensor systems are disclosed that include charge coupled device (CCD) pixels integrated with CMOS readout circuitry via separately bonded substrates. According to some embodiments, columns of image sensing pixels on a first substrate are arranged with overlapping gate structures to facilitate charge transfer between the pixels. At least one pixel is coupled to a first conductive pad that contacts (or is melded with) a second conductive pad from a second substrate bonded to the first substrate. The second substrate includes a readout circuit using one or more CMOS devices coupled to the second conductive pad to receive the accumulated charge from a given column of pixels. The resulting photodetector signal from the accumulated charge can be, for instance, amplified via a source follower component and ultimately read out to a column amplifier, and subjected to further processing and/or use in a given downstream system.

Abstract: Techniques to provide a low-power single-photon avalanche diode (SPAD) image. An example imaging device includes a SPAD array having a plurality of pixels configured to detect electromagnetic radiation, and a processing device configured to deactivate, based on an event count, a pixel of the SPAD array for a remaining duration of a first detection frame of the SPAD array. The pixel can remain deactivated for the remaining duration, and the remaining duration can span from a deactivation time until an end of the first SPAD frame. The processing device can be further configured to reactivate the pixel in a subsequent detection frame of the SPAD array.

Abstract: A camera for forming an image of a scene that moves relative to the camera and the method of forming that image are disclosed. The camera includes an imaging array having a plurality of CMOS pixel sensors having a plurality of columns and rows, an imaging system, and a controller. The imaging system causes a portion of an image of a scene to be projected on the imaging array such that the image of the scene moves across the imaging array in the column direction. First and second images of the scene are formed at first and second times chosen such that the image of the scene moves a predetermined number of rows of the imaging array between the first and second times. The controller combines pixel values from rows in the first image with rows in the second image that are separated by the predetermined number of rows.

Abstract: An imaging array and a method for operating the same are disclosed. The imaging array includes a plurality of light pixels and a sense amplifier. Each light pixel includes a photodetector that generates and couples a signal indicative of a light exposure to a light pixel node, a readout circuit, and a mixer that mixes a signal on the light pixel node with a pixel oscillator signal. The sense amplifier includes an input node that receives a signal from each light pixel, one light pixel at a time. The sense amplifier also includes a high pass filter that attenuates signals with frequencies less than a cutoff frequency and a mixer that demodulates the signal from the filter to provide a signal that is related to the potential on the light pixel node of the light pixel connected to the first input node.

Abstract: A photosensor and an imaging array utilizing the same are disclosed. The photosensor includes a light conversion region that has separate charge storage regions. The light conversion region includes a plurality of separate charge storage regions within a doped region, each charge collection region being doped such that the mobile charges generated by light striking that charge storage region are prevented from moving to an adjacent charge storage region. The photosensor also includes a plurality of transfer gates, having a gate region adjacent to a corresponding one of the charge storage regions and disposed between that charge storage region and a drain region. The charge collection regions and the drain regions are doped such that the mobile charges collected in the charge storage region will flow to the drain region when a first electric field is applied to the gate region.

Abstract: An image sensor and a method for using the same are disclosed. The image sensor includes an array of pixel sensors, a signal digitizing circuit, and a digitizing controller. The array of pixel sensors includes a plurality of pixel sensors. Each pixel sensor includes a photodetector, a charge conversion circuit, and a gate transistor. The charge conversion circuit generates a voltage signal that is related to a charge on the photodiode, and the gate transistor couples the voltage signal to a bit line in response to a first signal. The signal digitizing circuit converts the voltage signal to a plurality of output digital values. Each output digital value has a different level of digitization noise. One of the output digital values is selected for output in response to an output selection signal that is generated by the digitizing controller.

Abstract: An image sensor and method for using the image sensor to capture an image are disclosed. The image sensor includes an imaging array, a first block amplifier and a controller. A first plurality of pixels in the imaging array includes pixels having a photodiode connected to a first node by a gate transistor, a reset transistor connected between the first node and a reset node, a pixel amplifier having an input connected to the first node and an output, and an output gate for connecting the pixel amplifier output to an output bus. The sensor has a monitoring mode and an image capture mode. In the monitoring mode the reset node is connected to the first block amplifier whose output is monitored and used to trigger the image capture mode when the output exceeds a predetermined threshold.

Abstract: A CCD containing circuit and method for making the same. The circuit includes a CCD array and a protection circuit. The CCD array is constructed on an integrated circuit substrate and includes a plurality of gate electrodes that are insulated from the substrate by an insulating layer. The gate electrodes are connected to a conductor bonded to the substrate. The protection circuit is also constructed on the substrate. The protection circuit is connected to the conductor and to the substrate and protects the CCD array from both negative and positive voltage swings generated by electrostatic discharge events and the like. The protection circuit and the CCD can be constructed in the same integrated circuit fabrication process.

Abstract: A light sensor having a light conversion element between first and second electrodes is disclosed. The light conversion element includes a body of semiconductor material having first and second surfaces. The body of semiconductor material is of a first conductivity type and has doping elements in a concentration gradient that creates a first electrostatic field having a magnitude that varies monotonically from the first surface to the second surface. A bias circuit applies a variable potential between the first and second electrodes to create a second electrostatic field having a direction opposite to that of the first electrostatic field and a magnitude determined by the potential. One of the electrodes is transparent to light in a predetermined band of wavelengths. The body of semiconductor material can include an epitaxial body having a monotonically increasing concentration of a doping element as a function of the distance from one the surfaces.

Abstract: An image sensor having a two-dimensional array of CMOS pixel sensors, a row decoder and a column decoder is disclosed. The two-dimensional array of CMOS pixel sensors is organized as a plurality of rows and columns that are addressed with the aid of row and column decoders. At least one of the column decoder or the row decoder is located between two of the rows or two of the columns, respectively. X-rays are converted to light that is detected by the image sensor by a layer of scintillation material that overlies the two-dimensional array. The internally located decoder or decoders facilitate sensors in which the two-dimensional array includes a rectangular array having a chamfered corner such that rows or columns that extend into the chamfered corner have lengths that are less than rows or columns, respectively, that do not extend into the corners.

Abstract: An image sensor having a first substrate on which a CCD array is fabricated in a first fabrication system is disclosed. The CCD array includes a node through which charge from the pixels passes during a readout operation. The first substrate also includes a first FET fabricated on the first substrate in the first fabrication system, the first FET having a gate connected to the node and a source or drain connected to a first conducting pad on the first substrate. A capacitor connects the node to a second conducting pad on the first substrate. A switch is connected across the first capacitor such that the first capacitor is shorted when the first switch is closed. The first switch is controlled by a reset signal on a third conducting pad on the first substrate. The first substrate can be connected to a second substrate having amplification and control circuitry.

Abstract: An image sensor having a two-dimensional array of pixel sensors, a layer of scintillation material, and a controller is disclosed. The layer of scintillation material is adjacent to the two-dimensional array, the scintillation material emits light in response to x-rays impinging thereon. The pixel sensors detect this light. The controller reads out data stored in the two-dimensional array of pixel sensors and forms an image therefrom. The controller corrects the data for errors resulting from x-rays that generate electrons that are stored in the pixel sensors in the process of forming the image. In one aspect of the invention, the controller forms the image by causing the two-dimensional array to form a plurality of frames, each frame includes a measurement of a charge stored on each photodiode during a preceding time period. The controller selectively combines data from the frames to form the image.

Abstract: An image sensor and a method for using the same to capture an x-ray image are disclosed. The image sensor includes an output bus, a two dimensional array of pixel sensors that receives light from a layer of scintillation material and a controller. Each pixel sensor includes a capacitor, a plurality of light sensors, a charge converter and a transfer gate. Each of the light sensors includes a photodiode and a photodiode transfer gate that connects the photodiode to the capacitor. During readout, the charge on selected ones of the photodiodes is transferred to the capacitor. The charge on the capacitor is converted to a signal that is coupled to the output bus through the transfer gate by the controller. The number of photodiodes that are connected to the capacitor during the readout can be controlled to assure that the charge converter does not saturate.

Abstract: A camera having an exposure detector is disclosed. The camera includes an array of pixel sensors, CMOS circuitry that is separate from the array of pixel sensors, a guard region, and a current detector. The guard region separates the CMOS circuitry from the array of pixel sensors. The guard region is positioned such that the guard region is exposed to light when the array of pixel sensors is exposed to light. The current detector measures the current flowing from the guard region to a power rail when the guard region is biased to a predetermined potential and generates a start trigger signal when the current exceeds a threshold value. A controller resets the pixel sensors in response to the start trigger signal.

Abstract: A CCD imaging array and a charge measurement amplifier for use in such imaging arrays is disclosed. The array includes a plurality of pixels that accumulate charge when exposed to light, a readout amplifier having input and output ports. The readout amplifier has a variable gain that is set by a gain control signal. The readout amplifier also includes a reset path between the input and output ports, the path having an impedance controlled by a reset signal. A controller generates the gain control signal and the reset signal during a charge measurement cycle. Initially the gain is set to a first value after generating the reset signal. The gain is changed to a second value during the charge measurement cycle if the output signal exceeds a first threshold value. The readout amplifier can be constructed from an operational amplifier having a capacitive feedback loop.

Abstract: An imaging array having a CCD imaging array that includes a plurality of pixels that accumulate charge when exposed to light and a readout amplifier is disclosed. The readout amplifier includes an operational amplifier having an input and an output port and a feedback capacitor connecting the input and output ports and a variable impedance path between the input and output ports, the path having an impedance controlled by a reset signal. A reset signal generator generates the reset signal in three sequential phases in which the path between the input and output ports has three impedance values to provide a starting voltage at the amplifier input prior to the measurement of charge from each pixel that has reduced noise.