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).

  • Publication number: 20150382424
    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: Application
    Filed: June 25, 2014
    Publication date: December 31, 2015
    Inventors: David J. Knapp, Joseph A. Savage
  • Publication number: 20150382422
    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 time as the LEDs age. According to one embodiment, the method comprises applying drive currents to a plurality of LED chains substantially continuously to produce illumination, measuring a photocurrent induced on the photodetector in response to the illumination produced by each LED chain, one LED chain at a time, and received by the photodetector, and measuring a forward voltage developed across the photodetector by applying a non-operative drive current to the photodetector.
    Type: Application
    Filed: June 25, 2014
    Publication date: December 31, 2015
    Inventors: Horace C. Ho, Jason E. Lewis, David J. Knapp
  • Publication number: 20150382425
    Abstract: An illumination device described herein includes at least a phosphor converted LED, which is configured for emitting illumination for the illumination device, a first photodetector and a second photodetector. A spectrum of the illumination emitted from the phosphor converted LED comprises a first portion having a first peak emission wavelength and a second portion having a second peak emission wavelength, which differs from the first peak emission wavelength. The first photodetector has a detection range, which is configured for detecting only the first portion of the spectrum emitted by the phosphor converted LED. The second photodetector has a detection range, which is configured for detecting only the second portion of the spectrum emitted by the phosphor converted LED. Methods are provided herein for calibrating and controlling each portion of the phosphor converted LED spectrum, as if the phosphor converted LED were two separate LEDs.
    Type: Application
    Filed: June 25, 2014
    Publication date: December 31, 2015
    Inventors: Jason E. Lewis, Horace C. Ho, David J. Knapp
  • Publication number: 20150159818
    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: December 5, 2013
    Publication date: June 11, 2015
    Applicant: Ketra, Inc.
    Inventors: Fangxu Dong, Craig T. Phillips, David J. Knapp
  • Publication number: 20150102733
    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: December 17, 2014
    Publication date: April 16, 2015
    Inventors: David J. Knapp, Horace C. Ho, Jason Lewis
  • Patent number: 8991085
    Abstract: An electrical weapon system includes a power supply; a control electronics connected to the power supply; and an electrode pair, wherein the control electronics are configured to deliver a voltage having a determined voltage level and modulation across the electrode pair based on the electrode pair coming into contact with a target, and wherein the electrode pair is integrated into clothing or equipment of a user.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: March 31, 2015
    Assignee: Raytheon Company
    Inventor: David J. Knapp
  • Publication number: 20150022874
    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: Application
    Filed: July 17, 2013
    Publication date: January 22, 2015
    Inventors: Chadwick B. Martin, David J. Knapp, Gregory P. Hanauska
  • Publication number: 20150022873
    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: Application
    Filed: July 17, 2013
    Publication date: January 22, 2015
    Inventors: Chadwick B. Martin, David J. Knapp, Gregory P. Hanauska
  • Publication number: 20150022098
    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: Application
    Filed: June 16, 2014
    Publication date: January 22, 2015
    Inventor: David J. Knapp
  • Publication number: 20150015147
    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: Application
    Filed: June 16, 2014
    Publication date: January 15, 2015
    Inventor: David J. Knapp
  • Patent number: 8886047
    Abstract: Exemplary optical communication devices are described which, in certain embodiments, derive power optically from and communicate optically to a reading device. The communication devices may also receive data from modulated light from the reading device to achieve a bi-directional optical communication link between the self-powered optical communication device and the reading device. In some embodiments, the communication device is powered by ambient light, such as sunlight, captures data from a sensor, and communicates the stored data some time later to a reading device. In some embodiments, the communication device is powered locally and communicates through air, optical fiber, or other medium with another communication device.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: November 11, 2014
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 8773336
    Abstract: Illumination devices and related systems and methods are closed 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: August 5, 2010
    Date of Patent: July 8, 2014
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 8773300
    Abstract: A missile includes a radar system that has a radome through which a main antenna sends and receives signals. The radome includes a radome body and a radome tip include different transmissive materials, with for example the radome body primarily made of a lossy optically nontransparent material, and the radome tip primarily made of a lossless (permittivity with low imaginary part) glass material that may also be optically transparent. A laser may be used in conjunction with the radome to send and receive encoded signals. The laser may be located behind (aft of) the main antenna, and one or more optical fibers may extend into and/or along the radome to guide laser signals to the radome tip. The laser may be used to emit encoded signals so as to allow multiple radar systems operating in the same area at the same time to discriminate between different targets.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: July 8, 2014
    Assignee: Raytheon Company
    Inventors: Glafkos K. Stratis, Alphonso A. Samuel, Salvatore Bellofiore, David J. Knapp
  • Patent number: 8749172
    Abstract: An illumination device is provided having one or more illumination LEDs configured to provide illumination for the device. Along with the illumination LED is a reference LED. The illumination LED provide illumination during normal operation of the device, whereas the reference LED provides a reference illumination, but does not provide illumination during normal operation. A light detector can detect light from the illumination LED and the reference LED, and control circuitry can be used to compare light detected from the reference LED and the illumination LED to adjust a brightness for the device. The light detector can comprise a photo-detector or can comprise an LED, such as one of the illumination LEDs if more than one illumination LED is utilized. A method is also provided for controlling brightness of an illumination device.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: June 10, 2014
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 8674913
    Abstract: LED transceiver front end circuitry and related methods are disclosed that use an LED or LEDs to transmit light in a transmit state and to receive incident light in a receive state while helping to reduce effects of power supply noise and ripple and device leakage currents on incident light measurements in applications where such conditions exist. In the disclosed embodiments and implementations, a controlled voltage is applied across an LED or LEDs or a reference voltage is applied to an LED chain or LED to help reduce the effects of power supply noise and ripple and device leakage currents on incident light measurements during a receive state of operation. Further, with respect to the LED chain, one or more resistors are coupled in parallel to the LEDs in the LED chain.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: March 18, 2014
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 8606382
    Abstract: A communication system, network, interface, and port architecture are provided for transporting different types of data across a network. The network can be arranged by connecting the ports in a daisy chain fashion to achieve a ring architecture or topology. The network forwards data according to a specific network protocol, and any incoming data that follows that protocol will be sent onto the network. If the incoming data protocol does not match the network protocol, then the incoming data is not sent immediately to the network, but instead is sent to an input pin of a device upon the network specifically designed to receive that incoming data. The network, therefore, has ports that support both compliant and non-compliant incoming data, and the devices that produce such data.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: December 10, 2013
    Assignee: Standard Microsystems Corporation
    Inventors: Herbert Hetzel, David J. Knapp
  • Patent number: 8521035
    Abstract: Systems and methods for visible light communication are disclosed. In part, illumination devices and related systems and methods are disclosed that can be used for general illumination, lighting control systems, or other applications. The illumination devices synchronize preferentially to the AC mains to produce time division multiplexed channels in which control information can be communicated optically by the same light source that is producing illumination. Such illumination devices preferentially comprise LEDs for producing illumination, transmitting data, detecting ambient light, and receiving data, however, other light sources and detectors can be used. The physical layer can be used with a variety of protocols, such as ZigBee, from the Media ACcess (MAC) layer and higher.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: August 27, 2013
    Assignee: Ketra, Inc.
    Inventors: David J. Knapp, Horace C. Ho
  • Publication number: 20130183042
    Abstract: A system, remote control device and method are provided herein for communicating with and controlling various devices using visible light communication (VLC). According to one embodiment, a method is provided for extending a communication range of a visible light communication system comprising a remote control device and a plurality of controlled devices. Such a method may include, for example, transmitting a communication message from a remote control device to a first controlled device located within range of the remote control device, wherein the communication message is transmitted through free space using visible light, and extending the communication range of the visible light communication system to a second controlled device, which is located outside of the range of the remote control device, by using the first controlled device to retransmit the communication message through free space using visible light to the second controlled device.
    Type: Application
    Filed: February 21, 2013
    Publication date: July 18, 2013
    Inventors: David J. Knapp, Horace C. Ho
  • Patent number: 8471496
    Abstract: LED calibration systems and related methods are disclosed that use the photo-sensitivity of LEDs to correct for variations between LEDs during initial production and over the lifetime of systems using LEDs. The disclosed systems and methods include methods to set the color or color temperature produced by a group of LEDs during the manufacturing of a device such as a lamp, an LED display, or an LCD backlight, and maintaining such color or color temperature over the operating life of such a device. The methods involve measuring the intensity and/or wavelength of light produced by each LED within a group of LEDs and adjusting an amount of light generated by the LEDs to produce precise color and intensity from the group of LEDs. Two methods that operate some of the LEDs in photovoltaic or photoconductive mode to measure the light intensity produced by other LEDs in the group are presented.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: June 25, 2013
    Assignee: Ketra, Inc.
    Inventor: David J. Knapp
  • Patent number: 8466407
    Abstract: Asymmetric rotating stray light baffles are provided for conformal dome two-axis seekers having arch corrector optics mounted on the outer gimbal. A pair of side skirt baffles are mounted on opposite sides of the arch corrector optics on the outer gimbal extending forward beyond the transparent arch adjacent but not touching the inner surface of the dome and extending aft beyond the forward most receiver optic for all fields of regard (FOR).
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: June 18, 2013
    Assignee: Raytheon Company
    Inventors: Chadwick B. Martin, David J. Knapp, Richard A. Funk