In a solid-state imaging element that compares a reference signal and a pixel signal with each other, a frame rate is improved.

A differential amplifier circuit amplifies a difference in potential between a pair of input nodes and outputs the difference from an output node. A transfer transistor transfers charge from a photoelectric conversion element to a floating diffusion layer. A gate of a source follower transistor is connected to the floating diffusion layer, and a source thereof is connected to one of the pair of input nodes. A measurement unit measures a gate-source voltage of the source follower transistor and supplies a measured value. A correction arithmetic unit arithmetically calculates a correction value for correcting a potential of the other one of the pair of input nodes based on the measured value.

In a solid-state imaging element that compares a reference signal and a pixel signal with each other, a frame rate is improved.

A differential amplifier circuit amplifies a difference in potential between a pair of input nodes and outputs the difference from an output node. A transfer transistor transfers charge from a photoelectric conversion element to a floating diffusion layer. A gate of a source follower transistor is connected to the floating diffusion layer, and a source thereof is connected to one of the pair of input nodes. A measurement unit measures a gate-source voltage of the source follower transistor and supplies a measured value. A correction arithmetic unit arithmetically calculates a correction value for correcting a potential of the other one of the pair of input nodes based on the measured value.

Disclosed is a linear array ultra-fast scanning x-ray imaging device. The linear array x-ray imaging device is single photon sensitive, operating in frame output mode and including a pixel array Application Specific Integrated Circuit including the readout pixel array. The ASIC includes digital control logic and sufficient memory to accumulate digital output frames in various modes of operation prior to output from the ASIC, permitting advanced imaging functionalities directly on the ASIC, while maintaining a dynamic range of 16 bits and single photon sensitivity. The effective or secondary frames output from the pixel array ASIC can be tagged with user provided external triggers synchronizing the effective frames to the x-ray beam energy and/or to the movement of the x-ray source or imaged object. This enables dual energy imaging and ultra-fast scanning, without complex and costly conventional photon counting x-ray imaging sensors. The system architecture is simpler and higher performance.

Among a plurality of time measurement circuits configured to measure a time until a pixel counter saturates in the imaging sensor having the signal multiplication pixel structure, at least one time measurement circuit functions as a time counter that obtains a time from the pixel counter starting count of pulses until saturation and the other time measurement circuits function as a difference counter that obtains a difference between a time until a certain pixel counter saturates and a time until another pixel counter different from the certain pixel counter saturates. Then, a time from the pixel counter associated with the time measurement circuit that functions as a difference counter starting count of the pulses until saturation is found by calculation processing.

Among a plurality of time measurement circuits configured to measure a time until a pixel counter saturates in the imaging sensor having the signal multiplication pixel structure, at least one time measurement circuit functions as a time counter that obtains a time from the pixel counter starting count of pulses until saturation and the other time measurement circuits function as a difference counter that obtains a difference between a time until a certain pixel counter saturates and a time until another pixel counter different from the certain pixel counter saturates. Then, a time from the pixel counter associated with the time measurement circuit that functions as a difference counter starting count of the pulses until saturation is found by calculation processing.

To eliminate image defects produced by high-energy particles passing through a time delay integration image sensor, upstream detection is effected on the digital values supplied by the pixels of the same rank that have successively observed the same scene point. This detection makes it possible to ignore or to correct values from corrupted pixels in establishing the digital signal representing the luminance of an observed scene point. Detection is based on the calculation of the difference between a first digital value p.sub.i,a(t.sub.1) and a second digital value p.sub.i,b(t.sub.2) supplied by two pixels Px.sub.i,a and Px.sub.i,b that have observed the same scene point, subtracting the second value from the first, and comparing it to a predetermined threshold k. If this difference is above the threshold, the first value is too high, the first value is ignored in the summation Σ′.sub.i effected to establish the luminance of the scene point, replacing this value with the second value to which it has been compared. Alternatively it is replaced by a mean value or excluded from the calculation.

In time-delay-and-integrate (TDI) imaging, a charge-couple device (CCD) integrates and transfers charge across its columns. Unfortunately, the limited well depth of the CCD limits the dynamic range of the resulting image. Fortunately, TDI imaging can be implemented with a digital focal plane array (DFPA) that includes a detector, analog-to-digital converter (ADC), and counter in each pixel and transfer circuitry connected adjacent pixels. During each integration period in the TDI scan, each detector in the DFPA generates a photocurrent that the corresponding ADC turns into digital pulses, which the corresponding counter counts. Between integration periods, the DFPA transfers the counts from one column to the next, just like in a TDI CCD. The DFPA also non-destructively transfers some or all of the counts to a separate memory. A processor uses these counts to estimate photon flux and correct any rollovers caused by “saturation” of the counters.

Systems and methods are provided for enhancing object feature visibility for overhead imaging. In one embodiment, a computing system can obtain information associated with one or more locations of an imaging platform and one or more locations of a solar source. The system can determine one or more positional ranges of the imaging platform relative to the solar source based, at least in part, on such information. The positional ranges can be indicative of positions at which the imaging platform is to obtain image frames depicting at least a portion of a target object. The system can send, to the imaging platform, a set of data indicative of the positional ranges and can receive, from the imaging platform, a set of data indicative of the image frames depicting at least a portion of the target object. The image frames being captured based, at least in part, on the positional ranges.

The present disclosure provides a time delay integration (TDI) sensor using a rolling shutter. The TDI sensor includes multiple pixel columns. Each pixel column includes multiple pixels arranged in an along-track direction, wherein two adjacent pixels or two adjacent pixel groups in every pixel column have a separation space therebetween. The separation space is equal to a pixel height multiplied by a time ratio of a line time difference of the rolling shutter and a frame period, or equal to a summation of at least one pixel height and a multiplication of the pixel height by a time ratio of the line time difference and the frame period. The line time difference of the TDI sensor is changeable without changing the separation space.

A pixel for an image sensor includes a photon sensor, a memory, and an accumulator. The photon sensor element portion outputs a signal to an accumulator, which then may add value stored in memory together and may transfer the result to the memory of another pixel. The pixel may be analog or digital and may be used in a pixel array for compressed sensing imaging. During imaging, a pseudo-random mask may also be used. The data collected during imaging may be used in compressed sensing and may be sent to an offline storage to be processed.