Abstract: A dual or multi-energy range x-ray image sensor is implemented as side-by-side pixel arrays on a planar and monolithic semiconductor substrate as part of an x-ray object detector. Each pixel array in this side-by-side monolithic arrangement is designed to be responsive to a particular x-ray energy range or spectrum (i.e. a high-energy (HE) range or a low-energy (LE) range) to provide high object sensitivity and material discrimination capabilities. The side-by-side monolithic construction of pixel arrays improves alignment and spacing precision for improved image alignment among different arrays specialized in detecting different energy levels and signatures. Furthermore, integrated signal processing circuitry, placed on a radiation-shielded periphery of the pixel arrays, enables improved detection performance with enhanced noise reduction and/or sensitivity.

Abstract: A dual/multi-energy x-ray image sensor with stacked two-dimensional pixel arrays. Each pixel in one pixel array has a corresponding “overlaid” pixel in the other pixel array. The pixel arrays are stacked parallel and aligned so that they are nominally normal to the x-ray path, and so that a straight path taken by an x-ray photon from the x-ray source to a pixel in one pixel array will also nominally intersect the corresponding pixel in the other pixel array(s). The energy image sensor provides an x-ray scanning detector system, which has increased signal levels and signal-to-noise ratios over dual- or multi-energy detectors using linear diode arrays, specifically when the pixel arrays are TDI pixel arrays that offer higher sensitivities in high-speed line-scan applications. Signal processing circuitry is placed on a periphery of the pixel arrays and shielded. Dual-to-multiple energy applications can be accomplished by increasing the number of stacked pixel arrays.

Abstract: An X-ray line-scan camera utilizes an image transferring means to alter the optical path and thus eliminates the X-ray radiation damage on the electrical components of the camera system. The camera comprises a layer of scintillating material, a fiber optic face plate (FOFP) block, and an array of image sensors. One face of the FOFP block is bonded to the surface of the image sensors. The layer of scintillating material is placed on other face of the FOFP block and used to convert an impinging X-ray beam into visible light. The FOFP block is used to transfer the visible light from the scintillating layer onto the image sensor array, which in turn converts the visible light into electrical video signals. The FOFP block has a rotation angle of 32 to 40 degree relative to the impinging X-ray beam to prevent direct impingement of the X-ray beam onto the image sensors.

Abstract: A radiation damage resistant linear X-ray detector array system based on a unique buttable monolithic image sensor design and precision chip-on-board assembly technology includes at least one of the detector chips. Multiple chips of the image sensor may be butted end-to-end on a common printed circuit board to accommodate larger detection systems. A layer of scintillating material, such as Gd2O2S:Tb (GOS), CsI(Tl), or CdWO4, is placed on the image sensor to convert the impinging X-ray energies into visible light which can be detected efficiently by the image sensor array. A protective metal shield is fastened to the substrate to protect the sensitive circuits of the image sensor from X-ray radiation damage. A proper separation of sensitive circuits from the photodiode array on the sensor chip, coupled with precision registration of the sensor chips on the substrate, allows easy installation of the protective metal shield.

Abstract: A CMOS TDI image sensor consists of M pixels where each pixel is formed by a column of N TDI stages. Each TDI stage contains a photodiode that collects photo-charge and a pre-amplifier that proportionally converts the photo-charge to a voltage. Each TDI stage also has a set of capacitors, amplifiers, and switches for storage of the integrated signal voltages, where Correlated Double Sampling (CDS) technique (true or pseudo) maintains both photo-signal and reset voltages simultaneously. The CDS signal voltages can be passed from one TDI stage to the next TDI stage along a column for summing. The CDS signal voltages of the last TDI stages of M pixels are read out with a differential amplifier. This CMOS TDI structure is especially advantageous for implementing X-ray scanning detector systems requiring large pixel sizes and signal processing circuitry that is physically separated from the photodiode array for X-ray shielding.

Abstract: A radiation damage resistant linear X-ray detector array system based on a unique focusing principle reduces or eliminates the X-ray radiation damage on the electrical components of the detector system. The system includes a layer of scintillating material, a rod lens array, and an array of image sensors. The layer of scintillating material, such as Gd2O2S:Tb (GOS or GADOX), CsI(TI), or CdWO4, is placed on an image plane and used to convert the impinging X-ray energies into visible light which can be detected efficiently by the image sensor array. The rod lens array is used to focus the visible light after the X-ray flux has been converted. The photon energy of the visible light is collected with a scanning image sensor array that converts the photon energy proportionally into electrical video signals and enables the signals to be processed using standard signal and image processing software and equipment.

Abstract: A radiation damage resistant linear X-ray detector array system based on a unique focusing principle reduces or eliminates the X-ray radiation damage on the electrical components of the detector system. The system includes a layer of scintillating material, a rod lens array, and an array of image sensors. The layer of scintillating material, such as Gd2O2S:Tb (GOS or GADOX), CsI(TI), or CdWO4, is placed on an image plane and used to convert the impinging X-ray energies into visible light which can be detected efficiently by the image sensor array. The rod lens array is used to focus the visible light after the X-ray flux has been converted. The photon energy of the visible light is collected with a scanning image sensor array that converts the photon energy proportionally into electrical video signals and enables the signals to be processed using standard signal and image processing software and equipment.