Patent application number | Description | Published |
20100194956 | Apparatus and method for improving dynamic range and linearity of CMOS image sensor - Described herein is a circuit and related method for improving the dynamic range and the linearity characteristic of a CMOS image sensor. In various embodiments of the CMOS image sensor, a current sampler, a comparator, and a 1-bit memory are incorporated in each pixel circuit. In the image sensor, pixels are arranged in columns and a column slice is used to read the digital and analog singles from each column. In addition, a calibration circuit is incorporated in the sensor circuit for providing calibration current, which is used to generate calibration parameter. The image sensor operates in three non-overlapping modes: the difference mode, the WDR mode, and the calibration mode. The image sensor is switched among the three modes by control signals, which are provided to the image sensor by various control circuits. The image sensor normally operates in the difference mode and switches to the WDR mode when the difference between consecutive frames is over a threshold. The calibration mode allows the image sensor generate calibration parameters which are used to improve the linearity of the sensor through a interpolation method. | 08-05-2010 |
20110291019 | Quantum-limited highly linear CMOS detector for computer tomography - The invention provides a CMOS CT detector design with high linearity, quantum-limited noise, good scalability, high fill factor with a single CMOS chip utilizing synchronous partial quantization. The CMOS CT detector includes a pixel array, digital column buses, analog column buses, column processing circuits, a shift register, a control signal generation circuit, and a reference generation circuit, and implements a synchronous partial quantization scheme with reset, integration and analog readout phases. Each pixel of the pixel array further includes a photodiode; an integration capacitor; an OPAMP; a reset switch; a comparator; a 1-bit dynamic random-access-memory (DRAM) cell; a circuit block for enabling subtraction of a substantially fixed amount of charge from the integrated photocharge if the integrated photovoltage increases beyond the reference voltage; an integration node; an analog buffer; and a switch coupled between the output of the DRAM cell and the digital column bus. The inclusion of a level-shifter and a current front-end improves the linearity of the detector. | 12-01-2011 |
Patent application number | Description | Published |
20090241558 | COMPONENT COOLING SYSTEM - A component cooling system includes a component tank configured to receive a heat-generating device. The component tank is at least partially filled with a subcooled liquid at a first pressure and at a first temperature. A cryogenic system maintains the component tank at essentially the first temperature. The cryogenic system includes a heat exchange system thermally coupled with at least a portion of the component tank. The heat exchange system is at least partially filled with a second saturated liquid at a second pressure and at essentially the first temperature. A cryostat tank is fluidly-coupled with the heat exchange system and allows for pumpless displacement of the second saturated liquid between the heat exchange system and the cryostat tank. | 10-01-2009 |
20090247412 | SUPERCONDUCTING CABLE ASSEMBLY AND METHOD OF ASSEMBLY - An HTS cable assembly is provided which includes a cryostat or housing, an HTS wire bundle disposed longitudinally within the cryostat, and plural support members disposed between the HTS wire bundle and the cryostat. The support members are elongate, tubular members having resiliency in both the axial and radial directions. The support members are disposed between the HTS wire bundle and the inner surface of the cryostat in an arrangement that maintains and supports the HTS wire bundle in a spaced-apart relationship with respect to the inner surface of the cryostat. In addition, the plural support members are configured to substantially prevent relative movement between the HTS wire bundle and the cryostat. | 10-01-2009 |
20100087322 | ELECTRICITY TRANSMISSION COOLING SYSTEM - A cooling system includes a first section of high temperature superconducting (HTS) cable configured to receive a first flow of coolant and to permit the first flow of coolant to flow therethrough. The system may further include a second section of high temperature superconducting (HTS) cable configured to receive a second flow of coolant and to permit the second flow of coolant to flow therethrough. The system may further include a cable joint configured to couple the first section of HTS cable and the second section of HTS cable. The cable joint may be in fluid communication with at least one refrigeration module and may include at least one conduit configured to permit a third flow of coolant between said cable joint and said at least one refrigeration module through a coolant line separate from said first and second sections of HTS cable. Other embodiments and implementations are also within the scope of the present disclosure. | 04-08-2010 |
20100149707 | Parallel Connected HTS Utility Device and Method of Using Same - A method of controlling fault currents within a utility power grid is provided. The method may include coupling a superconducting electrical path between a first and a second node within the utility power grid and coupling a non-superconducting electrical path between the first and second nodes within the utility power grid. The superconducting electrical path and the non-superconducting electrical path may be electrically connected in parallel. The superconducting electrical path may have a lower series impedance, when operated below a critical current level, than the non-superconducting electrical path. The superconducting electrical path may have a higher series impedance, when operated at or above the critical current level, than the non-superconductor electrical path. | 06-17-2010 |
20110132631 | FAULT CURRENT LIMITING HTS CABLE AND METHOD OF CONFIGURING SAME - A cryogenically-cooled HTS cable is configured to be included within a utility power grid having a maximum fault current that would occur in the absence of the cryogenically-cooled HTS cable. The cryogenically-cooled HTS cable includes a continuous liquid cryogen coolant path for circulating a liquid cryogen. A continuously flexible arrangement of HTS wires has an impedance characteristic that attenuates the maximum fault current by at least 10%. The continuously flexible arrangement of HTS wires is configured to allow the cryogenically-cooled HTS cable to operate, during the occurrence of a maximum fault condition, with a maximum temperature rise within the HTS wires that is low enough to prevent the formation of gas bubbles within the liquid cryogen. | 06-09-2011 |
20110177954 | SUPERCONDUCTING ELECTRICITY TRANSMISSION SYSTEM - The present disclosure generally relates to a superconducting power grid having one or more AC/DC converters. The superconducting grid may further include one or more pairs of superconducting DC cables connecting each AC/DC converter. Each pair of superconducting DC cables may include a first positive polarity cable and a first negative polarity cable. The grid may also include at least one switching device configured to operatively connect at least one of the first and second AC/DC converters with at least one of the pairs of superconducting DC cables, the switching device further configured to adjust the polarity of at least one of the polarity cables. Other embodiments and implementations are also within the scope of the present disclosure. | 07-21-2011 |
20130065766 | ELECTRICITY TRANSMISSION COOLING SYSTEM - A cooling system includes a first section of high temperature superconducting (HTS) cable configured to receive a first flow of coolant and to permit the first flow of coolant to flow therethrough. The system may further include a second section of high temperature superconducting (HTS) cable configured to receive a second flow of coolant and to permit the second flow of coolant to flow therethrough. The system may further include a cable joint configured to couple the first section of HTS cable and the second section of HTS cable. The cable joint may be in fluid communication with at least one refrigeration module and may include at least one conduit configured to permit a third flow of coolant between said cable joint and said at least one refrigeration module through a coolant line separate from said first and second sections of HTS cable. | 03-14-2013 |