Patents by Inventor David J. Knapp

David J. Knapp 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: 9698458
    Abstract: A radio frequency (RF) module having a plurality of channels includes a heat sink having at least one tapered edge; a substrate disposed over a surface of the heat sink such that the tapered edge of the heat sink extends past a boundary of the substrate. RF, logic and power circuitry is disposed on the substrate and one or more RF signal ports are formed on an edge of the substrate to allow the RF module to be used in an array antenna having a brick architecture. The tapered edge heat sink provides both a ground plane for RF signal components and a thermal path for heat generating circuits disposed in the substrate.
    Type: Grant
    Filed: August 26, 2015
    Date of Patent: July 4, 2017
    Assignee: Raytheon Company
    Inventors: Glafkos K. Stratis, Douglas Mills, Kevin R. Hopkins, Raymond A. Graffam, David J. Knapp, Michael S. Smith
  • Publication number: 20170179562
    Abstract: An ultra-wide band (UWB) radio frequency (RF)/optical aperture includes a substrate having a plurality of regions. The plurality of regions may have varying characteristics and properties. In some embodiments, the plurality of regions includes a first region having a first relative dielectric constant and being transparent to signals having a frequency in a first frequency range, a second region contained in the first region and having a second relative dielectric constant and being transparent to signals having a frequency in a second frequency range, and a third region contained within the second region and having a third relative dielectric constant and being transparent to signals having a frequency in a third frequency range.
    Type: Application
    Filed: December 16, 2015
    Publication date: June 22, 2017
    Applicant: Raytheon Company
    Inventors: Glafkos K. Stratis, Douglas Mills, Kevin R. Hopkins, Raymond A. Graffam, Michael S. Smith, David J. Knapp
  • Patent number: 9668314
    Abstract: A linear multi-color LED illumination device that produces uniform color throughout the output light beam without the use of excessively large optics or optical losses is disclosed herein. Embodiments for improving color mixing in the linear illumination device include, but are not limited to, a shallow dome encapsulating a plurality of emission LEDs within an emitter module, a unique arrangement of a plurality of such emitter modules in a linear light form factor, and special reflectors designed to improve color mixing between the plurality of emitter modules. In addition to improved color mixing, the illumination device includes a light detector and optical feedback for maintaining precise and uniform color over time and/or with changes in temperature. The light detector is encapsulated within the shallow dome along with the emission LEDs and is positioned to capture the greatest amount of light reflected by the dome from the LED having the shortest emission wavelength.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: May 30, 2017
    Assignee: Ketra, Inc.
    Inventors: Fangxu Dong, Craig T. Phillips, David J. Knapp
  • Patent number: 9651632
    Abstract: An illumination device comprising a plurality of light emitting diodes (LEDs) and a method for calibrating the illumination device is provided herein. According to one embodiment, the method may include subjecting a first LED to a first ambient temperature, measuring a forward voltage developed across the first LED upon applying a relatively small drive current to the first LED, detecting at least a first, a second and a third luminous flux output from the first LED upon successively applying at least a first, a second and a third drive current to the first LED, and storing results of the measuring and detecting steps within the illumination device to calibrate the first LED at the first ambient temperature. In some embodiments, the first LED may be subjected to a second ambient temperature, which is different from the first ambient temperature, and the method may repeat the steps of measuring, detecting and storing to calibrate the first LED at the second ambient temperature.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: May 16, 2017
    Assignee: Ketra, Inc.
    Inventors: David J. Knapp, Horace C. Ho, Joseph A. Savage
  • Publication number: 20170105260
    Abstract: An illumination device and method is provided herein for calibrating individual LEDs in the illumination device, so as to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature.
    Type: Application
    Filed: December 22, 2016
    Publication date: April 13, 2017
    Applicant: Ketra, Inc.
    Inventors: Horace Ho, Jason E. Lewis, David J. Knapp
  • Publication number: 20170062894
    Abstract: A radio frequency (RF) module having a plurality of channels includes a heat sink having at least one tapered edge; a substrate disposed over a surface of the heat sink such that the tapered edge of the heat sink extends past a boundary of the substrate. RF, logic and power circuitry is disposed on the substrate and one or more RF signal ports are formed on an edge of the substrate to allow the RF module to be used in an array antenna having a brick architecture. The tapered edge heat sink provides both a ground plane for RF signal components and a thermal path for heat generating circuits disposed in the substrate.
    Type: Application
    Filed: August 26, 2015
    Publication date: March 2, 2017
    Inventors: Glafkos K. Stratis, Douglas Mills, Kevin R. Hopkins, Raymond A. Graffam, David J. Knapp, Michael S. Smith
  • Patent number: 9578724
    Abstract: An illumination device comprising a plurality of light emitting diodes (LEDs) and a method for controlling the illumination device while avoiding flicker in the LED output is provided herein. According to one embodiment, the method may include driving the plurality of LEDs substantially continuously with drive currents configured to produce illumination, periodically turning the plurality of LEDs off for short durations of time during a first period to take measurements or communicate optical data, and increasing the drive currents supplied to the plurality of LEDs by a small amount when the LEDs are on during the first period to compensate for lack of illumination when the LEDs are periodically turned off during the first period.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: February 21, 2017
    Assignee: Ketra, Inc.
    Inventors: David J. Knapp, Horace C. Ho, Joseph A. Savage
  • Publication number: 20170042005
    Abstract: Intelligent illumination device are disclosed that use components in an LED light to perform one or more of a Wide variety of desirable lighting functions for very low cost. The LEDs that produce light can be periodically turned off momentarily, for example, for a duration that the human eye cannot perceive, in order for the light to receive commands optically. The optically transmitted commands can be sent to the light, for example, using a remove control device. The illumination device can use the LEDs that are currently off to receive the data and then configure the light accordingly, or to measure light. Such light can be ambient light for a photosensor function, or light from other LEDs in the illumination device to adjust the color mix.
    Type: Application
    Filed: October 18, 2016
    Publication date: February 9, 2017
    Applicant: Ketra, Inc.
    Inventor: David. J. Knapp
  • Patent number: 9557214
    Abstract: An illumination device and method is provided herein for calibrating individual LEDs in the illumination device, so as to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature.
    Type: Grant
    Filed: June 25, 2014
    Date of Patent: January 31, 2017
    Assignee: Ketra, Inc.
    Inventors: Horace C. Ho, Jason E. Lewis, David J. Knapp
  • Patent number: 9509525
    Abstract: Intelligent illumination device are disclosed that use components in an LED light to perform one or more of a wide variety of desirable lighting functions for very low cost. The LEDs that produce light can be periodically turned off momentarily, for example, for a duration that the human eye cannot perceive, in order for the light to receive commands optically. The optically transmitted commands can be sent to the light, for example, using a remove control device. The illumination device can use the LEDs that are currently off to receive the data and then configure the light accordingly, or to measure light. Such light can be ambient light for a photosensor function, or light from other LEDs in the illumination device to adjust the color mix.
    Type: Grant
    Filed: July 7, 2010
    Date of Patent: November 29, 2016
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Publication number: 20160242255
    Abstract: A linear multi-color LED illumination device that produces uniform color throughout the output light beam without the use of excessively large optics or optical losses is disclosed herein. Embodiments for improving color mixing in the linear illumination device include, but are not limited to, a shallow dome encapsulating a plurality of emission LEDs within an emitter module, a unique arrangement of a plurality of such emitter modules in a linear light form factor, and special reflectors designed to improve color mixing between the plurality of emitter modules. In addition to improved color mixing, the illumination device includes a light detector and optical feedback for maintaining precise and uniform color over time and/or with changes in temperature. The light detector is encapsulated within the shallow dome along with the emission LEDs and is positioned to capture the greatest amount of light reflected by the dome from the LED having the shortest emission wavelength.
    Type: Application
    Filed: April 28, 2016
    Publication date: August 18, 2016
    Applicant: Ketra, Inc.
    Inventors: Fangxu Dong, Craig T. Phillips, David. J. Knapp
  • Patent number: 9392663
    Abstract: An illumination device and method is provided herein for controlling individual light emitting diodes (LEDs) in an LED illumination device, so that a desired luminous flux and a desired chromaticity of the device can be maintained over changes in drive current and temperature. According to one embodiment, the illumination device comprises a plurality of emission LEDs, a storage medium, an LED driver and receiver circuit and a control circuit. The storage medium may store a table of calibration values correlating forward voltage and drive current to chromaticity and luminous flux at a plurality of temperatures for each of the plurality of emission LEDs. The LED driver and receiver circuit may apply respective drive currents to the emission LEDs to produce substantially continuous illumination, and may periodically turn the emission LEDs off to measure operating forward voltages that develop across each emission LED.
    Type: Grant
    Filed: June 25, 2014
    Date of Patent: July 12, 2016
    Assignee: Ketra, Inc.
    Inventors: David J. Knapp, Joseph A. Savage
  • Patent number: 9386668
    Abstract: Intelligent illumination device are disclosed that use components in an LED light to perform one or more of a wide variety of desirable lighting functions for very low cost. The LEDs that produce light can be periodically turned off momentarily, for example, for a duration that the human eye cannot perceive, in order for the light to receive commands optically. The optically transmitted commands can be sent to the light, for example, using a remove control device. The illumination device can use the LEDs that are currently off to receive the data and then configure the light accordingly, or to measure light. Such light can be ambient light for a photosensor function, or light from other LEDs in the illumination device to adjust the color mix.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: July 5, 2016
    Assignee: Ketra, Inc.
    Inventors: David J. Knapp, Horace C. Ho, Jason Lewis
  • Patent number: 9360174
    Abstract: A linear multi-color LED illumination device that produces uniform color throughout the output light beam without the use of excessively large optics or optical losses is disclosed herein. Embodiments for improving color mixing in the linear illumination device include, but are not limited to, a shallow dome encapsulating a plurality of emission LEDs within an emitter module, a unique arrangement of a plurality of such emitter modules in a linear light form factor, and special reflectors designed to improve color mixing between the plurality of emitter modules. In addition to improved color mixing, the illumination device includes a light detector and optical feedback for maintaining precise and uniform color over time and/or with changes in temperature. The light detector is encapsulated within the shallow dome along with the emission LEDs and is positioned to capture the greatest amount of light reflected by the dome from the LED having the shortest emission wavelength.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: June 7, 2016
    Assignee: Ketra, Inc.
    Inventors: Fangxu Dong, Craig T. Phillips, David J. Knapp
  • Patent number: 9347743
    Abstract: An offset aperture two-axis gimbaled optical system comprises a two-axis gimbal and an optics assembly that is mounted on the inner gimbal and offset radially from the rotation axis of the outer gimbal. The optics assembly is suitably offset so that its optical aperture does not overlap the rotation axis of the outer gimbal and its optical aperture is symmetric about the rotation axis of the inner gimbal. In different applications, the offset aperture provides for reduced optical aberrations and improved utilization of the available packaging volume to accommodate multiple offset aperture optics assemblies.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: May 24, 2016
    Assignee: Raytheon Company
    Inventors: Chadwick B. Martin, David J. Knapp, Gregory P. Hanauska
  • Patent number: 9335126
    Abstract: An offset aperture gimbaled optical system comprises a gimbal and an optics assembly that is mounted on an inner gimbal and offset radially from an axis of symmetry (and rotation axis) of a conformal dome. An optical corrector adjacent the inner surface of the conformal dome encompasses the field-of-view of the optics assembly as the inner gimbal rotates about its rotation axis. The corrector is fixed with respect to the inner gimbal's rotation axis while it rotates about the axis of symmetry. The optical corrector comprises an aspheric transparent arch having an optical corrector shape and position responsive to a shape of the conformal dome at the offset position of the optics assembly. In different applications, the offset aperture provides for reduced optical aberrations and improved utilization of the available packaging volume to accommodate multiple offset aperture optics assemblies.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: May 10, 2016
    Assignee: Raytheon Company
    Inventors: Chadwick B. Martin, David J. Knapp, Gregory P. Hanauska
  • Patent number: 9295112
    Abstract: Illumination devices and related systems and methods are disclosed that can be used for LCD (Liquid Crystal Display) backlights, LED lamps, or other applications. The illumination devices can include a photo detector, such as a photodiode or an LED or other light detecting device, and one or more LEDs of different colors. A related method can be implemented using these illumination devices to maintain precise color produced by the blended emissions from such LEDs. One application for the illumination devices is backlighting for FSC (Field Sequential Color) LCDs (Liquid Crystal Displays). FSC LCDs temporally mix the colors in an image by sequentially loading the red, green, and blue pixel data of an image in the panel and flashing the different colors of an RGB backlight. Precise and uniform color temperature across such a display can be advantageously maintained by continually monitoring ratios of photodiode currents induced by the different colored LEDs in each illumination device as each color is flashed.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: March 22, 2016
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 9276766
    Abstract: Display calibration systems and related methods are disclosed that use photo-sensitivity of LEDs to correct for variations between LEDs during initial production and over lifetime for display systems. The display devices include arrays of LEDs and use photo-sensitivity of the LEDs to correct for variations between LEDs. Such LED arrays can produce images directly as in LED billboards and sports arena scoreboards, and smaller Organic LED (OLED) displays, or can produce the backlight for LCD screens for instance. Variations in LED brightness and color can be compensated for in order for such a display to have uniform color and brightness. This compensation is performed in the embodiments disclosed by measuring the signal induced on each LED by uniform incident light as a measurement of the photo-sensitivity of the LEDs.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: March 1, 2016
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 9237620
    Abstract: An illumination device comprising a plurality of light emitting diodes (LEDs) and a method for controlling the illumination device, so as to maintain a desired luminous flux and/or a desired color point of the device over variations in temperature and process, is provided herein. According to one embodiment, the method may include measuring a forward voltage developed across a first LED of the illumination device upon applying a first drive current to the first LED, determining a drive current needed to achieve a desired luminous flux from the first LED using the measured forward voltage, a table of stored calibration values correlating forward voltage and drive current to luminous flux at a plurality of different temperatures, and one or more interpolation techniques, and driving the first LED with the determined drive current to produce illumination having the desired luminous flux. The steps of measuring, determining and driving may be performed for each of the plurality of LEDs.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: January 12, 2016
    Assignee: Ketra, Inc.
    Inventors: David J. Knapp, Horace C. Ho, Joseph A. Savage
  • Publication number: 20150377699
    Abstract: An illumination device and method is provided herein for calibrating individual LEDs in the illumination device, so as to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature.
    Type: Application
    Filed: June 25, 2014
    Publication date: December 31, 2015
    Inventors: Horace C. Ho, Jason E. Lewis, David J. Knapp