Patents by Inventor Khai Minh Le

Khai Minh Le 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).

  • Patent number: 7336767
    Abstract: A method for improving resolution of X-ray radiography systems of the type used to obtain images of internal features of human bodies or to view contents of luggage articles, cargo containers and the like comprises positioning a plurality of baffle plates between the rear surface of an X-ray radiation detector array and a back stop used to limit transmitted X-ray radiation to a safe level. The baffle plates are made of a high atomic-number metal such as iron or lead which reduces by absorption, scattering or other attenuating processes the intensity of X-ray radiation back scattered from the back-stop onto the detector array, thus reducing noise contributions to signals output from detector elements of the array and thereby improving the quality of radiographic images formed from detector output signals.
    Type: Grant
    Filed: March 8, 2005
    Date of Patent: February 26, 2008
    Inventor: Khai Minh Le
  • Patent number: 7139367
    Abstract: A method and apparatus for processing signals output from an array of X-ray radiation detectors which receive X-ray radiation emanating from an object irradiated by a source beam of X-ray radiation, to thereby produce an visual image of internal object features, utilizes repetitive sampling P times and digital accumulation of signals output from each detector to increase signal-to-noise ratio of the images by the factor 1/?P. In a basic embodiment, each of the N detectors in a linear detector array is sampled P times. In another embodiment, artifacts resulting from decay of detector pre-amplifier output voltages on capacitors of low-pass filter circuits, referred to as pseudo-integrators, are reduced by sequentially sampling and accumulating each of N detector amplifier output voltages P times in turn, and repeating the sampling and accumulating sequence Q times, thereby reducing variations in the P×Q accumulated values between the first and last detector channels of an N detector array.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: November 21, 2006
    Inventor: Khai Minh Le
  • Patent number: 6940733
    Abstract: A switch state controller generating a pulse train is used in a power converter utilizing a plurality of converter stages all simultaneously controlled by a single switch controlled by said pulse train. On time of the pulse train is controlled according to an input or interim node characteristic of the supply and period is controlled by a characteristic of the output of the converter. This allows development of AC-to-DC converters, including power-factor-correction converters, and DC to DC converters with high conversion ratio with minimal parts count & high reliability.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: September 6, 2005
    Assignee: Supertex, Inc.
    Inventors: David Chalmers Schie, Alexander Mednik, James Hung Nguyen, Sang Ton Ngo, Khai Minh Le, Wei Gu, Larry Kerenyi
  • Patent number: 6917504
    Abstract: An apparatus and method for adaptively controlling power supplied to a hot-pluggable subsystem controls the inrush current of the hot-pluggable subsystem when the subsystem is coupled to another system that supplies power, and optionally other signal connections. The apparatus and method adaptively control a pass device by detecting the voltage at the gate of the pass device during initial charging of the gate. The gate voltage may be sampled and used subsequently to control the operation of the pass device, and short-circuit conditions may be detected by determining that the miller effect does not change the charging of the gate capacitance. Automatic restart circuitry can be included to generate multiple startup attempts, and under-voltage lockout circuitry and power-on-reset timers can be used to provide a robust solution. The apparatus and method can be adapted to provide a three terminal device that does not require a feedback connection from a power supply output.
    Type: Grant
    Filed: May 2, 2001
    Date of Patent: July 12, 2005
    Assignee: Supertex, Inc.
    Inventors: James Hung Nguyen, Sang Ton Ngo, David Chalmers Schia, Ladislas G. Kerenyi, Khai Minh Le
  • Patent number: 6839403
    Abstract: An image display storage and retrieval system provides a mechanism to transmit x-ray images of parcels to one or more remote workstations. The images may be annotated at these workstations to specifically identify articles to be targeted for more thorough investigation.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: January 4, 2005
    Assignee: Rapiscan Security Products (USA), Inc.
    Inventors: Andreas F. Kotowski, Khai Minh Le, Douglas Roy Gillard-Hickman
  • Publication number: 20040105283
    Abstract: A switch state controller generating a pulse train is used in a power converter utilizing a plurality of converter stages all simultaneously controlled by a single switch controlled by said pulse train. On time of the pulse train is controlled according to an input or interim node characteristic of the supply and period is controlled by a characteristic of the output of the converter. This allows development of AC-to-DC converters, including power-factor-correction converters, and DC to DC converters with high conversion ratio with minimal parts count & high reliability.
    Type: Application
    Filed: August 22, 2003
    Publication date: June 3, 2004
    Inventors: David Chalmers Schie, Alexander Mednik, James Hung Nguyen, Sang Ton Ngo, Khai Minh Le, Wei Gu, Ladislas G. Kerenyi
  • Patent number: 6525515
    Abstract: A feedback apparatus and method for adaptively controlling power supplied to a hot-pluggable subsystem controls the inrush current of the hot-pluggable subsystem upon application of power. The apparatus and method adaptively control a pass device by detecting the current through the pass device during initial charging of a load capacitance and scaling back the turn-on rate at the pass device control terminal input in conformity with the detected current and a predetermined rate set by a ramp generator. A ramp capacitor is coupled to the control terminal of the pass device through a diode to permit use of the capacitor for timing purposes as well as preventing transient turn-on of the pass device during initial application of power.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: February 25, 2003
    Assignee: Supertex, Inc.
    Inventors: Sang Ton Ngo, James Hung Nguyen, David Chalmera Schie, Ladislas G. Kerenyi, Khai Minh Le
  • Publication number: 20020166073
    Abstract: An apparatus and method for adaptively controlling power supplied to a hot-pluggable subsystem controls the inrush current of the hot-pluggable subsystem when the subsystem is coupled to another system that supplies power, and optionally other signal connections. The apparatus and method adaptively control a pass device by detecting the voltage at the gate of the pass device during initial charging of the gate. The gate voltage may be sampled and used subsequently to control the operation of the pass device, and short-circuit conditions may be detected by determining that the miller effect does not change the charging of the gate capacitance. Automatic restart circuitry can be included to generate multiple startup attempts, and under-voltage lockout circuitry and power-on-reset timers can be used to provide a robust solution. The apparatus and method can be adapted to provide a three terminal device that does not require a feedback connection from a power supply output.
    Type: Application
    Filed: May 2, 2001
    Publication date: November 7, 2002
    Inventors: James Hung Nguyen, Sang Ton Ngo, David Chalmers Schie, Ladislas G. Kerenyi, Khai Minh Le
  • Patent number: 6473487
    Abstract: A method and apparatus for determining a specified physical characteristic in an object exposes the object to at least two angularly fixed sources of electromagnetic radiation to create projected images of the object. The sources are rotationally scanned about the object so as to oscillate in an angular range about the object. The sources are relatively stationary to one another. A three dimensional reconstructed image of the object based on the projected images of the object is created and examined for a specified physical characteristic in the object.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: October 29, 2002
    Assignee: Rapiscan Security Products, Inc.
    Inventor: Khai Minh Le