Patents by Inventor Xinqiao Liu
Xinqiao Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20130258153Abstract: A camera adapted for taking pictures of a moving scene is disclosed. The camera includes an imaging array, a plurality of charge-coupled device (CCD) shift registers, and a controller. The imaging array includes a plurality of CMOS pixel sensors organized as a plurality of columns and rows. The image moves in the column direction. One CCD shift register corresponds to each of the columns. Each CMOS pixel sensor includes a first transfer gate that transfers charge accumulated in the pixel sensor to a corresponding cell in the CCD shift register. The controller controls the CCD shift registers such that charge stored in a first cell in a CCD shift register is moved to a second cell in the CCD shift register where the charge is combined with charge accumulated by the pixel sensor that is connected to the second cell, the combined charge being generated from the same image pixel.Type: ApplicationFiled: March 30, 2012Publication date: October 3, 2013Inventors: Boyd Fowler, Xinqiao Liu, Steven Onishi
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Patent number: 8159574Abstract: An imaging array and method for using the same to capture an image are disclosed. The imaging array includes an array of pixel sensors and a controller. Each pixel sensor includes a dual-ported photodiode characterized by ports having first and second gates, and a charge conversion circuit. The charge conversion circuit generates a signal that is a function of a charge on the dual-ported photodiode when the first gate in the dual-ported photodiode is activated to transfer a charge on the dual-ported photodiode to the charge conversion circuit. The controller applies a potential to the second gates and measures a current flowing out of the second gates, each second port passing charge stored in the photodiode connected to the second port when a potential in the photodiode exceeds the applied potential. The controller determines an average light intensity incident on the array of pixel sensors.Type: GrantFiled: December 8, 2008Date of Patent: April 17, 2012Assignee: BAE Systems Imaging Solutions, Inc.Inventors: Xinqiao Liu, Boyd Fowler
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Publication number: 20120075514Abstract: A hybrid imaging array and method for using the same is disclosed. The image array includes a low-light imaging array and a color imaging array. The two imaging arrays can be utilized separately or in conjunction with one another. The low-light imaging array is optimized for night vision or situations in which the light levels are too low to allow a conventional color image to be formed by the color imaging array. The color imaging array is optimized for daylight or color photography. The low-light imaging array can be utilized in conjunction with the color imaging array to provide a color image with reduced noise.Type: ApplicationFiled: September 28, 2010Publication date: March 29, 2012Inventors: Xinqiao Liu, Feng Xiao, Boyd Fowler
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Patent number: 8130294Abstract: An imaging array and method for capturing an image utilizing the same are disclosed. The imaging array includes an array of pixel sensors in which each pixel includes a dual-ported photodiode or photogate and a charge conversion circuit. The charge conversion circuit generates a voltage signal that is a function of a charge on the dual-ported photodiode. The controller applies a potential that varies over the exposure to the second gates in the dual-ported photodiodes, each second port passing charge stored in the photodiode connected to the second port when a potential in the photodiode exceeds the applied potential. The potential is chosen such that charge flows through the second gates of pixel sensors that are exposed to light intensities greater than a first threshold intensity during the exposure.Type: GrantFiled: December 8, 2008Date of Patent: March 6, 2012Assignee: BAE Systems Imaging Solutions, Inc.Inventors: Boyd Fowler, Xinqiao Liu
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Patent number: 8071410Abstract: 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.Type: GrantFiled: December 14, 2009Date of Patent: December 6, 2011Assignee: BAE Systems Imaging Solutions Inc.Inventors: David D. Wen, Xinqiao Liu, Ahn N. Vu, Steven Kiyoshi Onishi
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Patent number: 7977716Abstract: 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.Type: GrantFiled: March 17, 2008Date of Patent: July 12, 2011Assignee: Fairchild Imaging, Inc.Inventor: XinQiao Liu
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Patent number: 7812879Abstract: 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.Type: GrantFiled: October 30, 2007Date of Patent: October 12, 2010Assignee: Fairchild ImagingInventors: Xinqiao Liu, Hung Do
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Publication number: 20100141819Abstract: An imaging array and method for capturing an image utilizing the same are disclosed. The imaging array includes an array of pixel sensors in which each pixel includes a dual-ported photodiode or photogate and a charge conversion circuit. The charge conversion circuit generates a voltage signal that is a function of a charge on the dual-ported photodiode. The controller applies a potential that varies over the exposure to the second gates in the dual-ported photodiodes, each second port passing charge stored in the photodiode connected to the second port when a potential in the photodiode exceeds the applied potential. The potential is chosen such that charge flows through the second gates of pixel sensors that are exposed to light intensities greater than a first threshold intensity during the exposure.Type: ApplicationFiled: December 8, 2008Publication date: June 10, 2010Inventors: Boyd Fowler, Xinqiao Liu
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Publication number: 20100141817Abstract: An imaging array and method for using the same to capture an image are disclosed. The imaging array includes an array of pixel sensors and a controller. Each pixel sensor includes a dual-ported photodiode characterized by ports having first and second gates, and a charge conversion circuit. The charge conversion circuit generates a signal that is a function of a charge on the dual-ported photodiode when the first gate in the dual-ported photodiode is activated to transfer a charge on the dual-ported photodiode to the charge conversion circuit. The controller applies a potential to the second gates and measures a current flowing out of the second gates, each second port passing charge stored in the photodiode connected to the second port when a potential in the photodiode exceeds the applied potential. The controller determines an average light intensity incident on the array of pixel sensors.Type: ApplicationFiled: December 8, 2008Publication date: June 10, 2010Inventors: Xinqiao Liu, Boyd Fowler
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Publication number: 20100091166Abstract: 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.Type: ApplicationFiled: December 14, 2009Publication date: April 15, 2010Inventors: David D. Wen, Xinqiao Liu, Ahn N. Vu, Steven Kiyoshi Onishi
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Patent number: 7655493Abstract: 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.Type: GrantFiled: July 14, 2005Date of Patent: February 2, 2010Assignee: Fairchild Imaging, IncInventors: David D. Wen, Xinqiao Liu, Ahn N. Vu, Steven Kiyoshi Onishi
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Patent number: 7655918Abstract: 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.Type: GrantFiled: July 26, 2006Date of Patent: February 2, 2010Assignee: Fairchild Imaging, IncInventors: Xinqiao Liu, Boyd Fowler
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Publication number: 20100002115Abstract: A photodetector array and method for making the same are disclosed. The photodetector array includes a two-dimensional array of pixels and a controller. Each pixel includes a photodetector and a readout circuit, the readout circuit coupling that pixel to a corresponding bit line when a readout signal is received on a corresponding row line. The controller generates the row selection commands and processes signals on the bit lines. The photodetector array is divided into a plurality of sub-chips fabricated on a semiconductor substrate and having a plurality of metal conductors overlying the substrate. The sub-chips include a plurality of slave sub-chips, each slave sub-chip includes a row decode circuit, and a plurality of the rows of pixels, the row decode circuit in one of the slave-sub-chips providing the readout signals on row lines in that sub-chip in response to one of the row selection commands.Type: ApplicationFiled: July 3, 2008Publication date: January 7, 2010Inventor: XinQiao Liu
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Patent number: 7615754Abstract: 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.Type: GrantFiled: March 8, 2007Date of Patent: November 10, 2009Assignee: Fairchild Imaging, Inc.Inventors: XinQiao Liu, Boyd Fowler
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Patent number: 7605376Abstract: 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.Type: GrantFiled: October 29, 2007Date of Patent: October 20, 2009Assignee: Fairchild Imaging, Inc.Inventor: Xinqiao Liu
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Patent number: 7592577Abstract: 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.Type: GrantFiled: April 28, 2008Date of Patent: September 22, 2009Assignee: Fairchild Imaging, Inc.Inventor: XinQiao Liu
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Publication number: 20090230436Abstract: 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.Type: ApplicationFiled: March 17, 2008Publication date: September 17, 2009Inventor: XinQiao Liu
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Publication number: 20090108311Abstract: An imaging array and method for operating the same is disclosed. The imaging array includes a semiconductor substrate having an epitaxial layer of semiconductor material deposited on a first surface thereof. A plurality of photodiodes is formed in a top surface of the epitaxial layer. The imaging array also includes a depletion layer underlying the photodiodes and disposed between the epitaxial layer and the semiconductor substrate. The depletion layer is connected to a power rail for removing electrons collected in the depletion layer. The depletion layer collects electrons generated by x-ray interactions in the substrate. The depletion layer can also be biased such that the depletion layer collects electrons collected by the photodiodes to provide a reset operation for the imaging array. The current flowing through the depletion layer can be used to generate a trigger signal indicating the start of an x-ray exposure.Type: ApplicationFiled: October 25, 2007Publication date: April 30, 2009Inventor: Xinqiao Liu
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Publication number: 20090109313Abstract: 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.Type: ApplicationFiled: October 30, 2007Publication date: April 30, 2009Inventors: Xinqiao Liu, Hung Do
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Publication number: 20090108207Abstract: 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.Type: ApplicationFiled: October 29, 2007Publication date: April 30, 2009Inventor: Xinqiao Liu