Patents by Inventor John M. Davenport

John M. Davenport 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: 10892615
    Abstract: A circuit for mitigating electric shock including an external impedance detection circuit and a test and holdoff circuit. The external impedance detection circuit detects a presence of an external impedance, such as by detecting a relative change in voltage from a startup condition and a test condition. The test and holdoff circuit inhibits operation of a power converter which delivers power to be consumed by a load. The startup condition is defined by mains power applied to the circuit with negligible power consumed by a load. The test condition is defined by non-zero power delivered to the load. According to another aspect, the external impedance detection circuit measures an input voltage using a high input power which is greater than a shock hazard threshold at a duration less than a threshold time duration and determines the presence of the external impedance based on low pass filters having different time constants.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: January 12, 2021
    Assignee: ENERGY FOCUS, INC.
    Inventors: Jeremiah A. Heilman, John M. Davenport
  • Patent number: 10761538
    Abstract: Enhanced systems and methods for collision avoidance of a high value asset with reflective beacons around it using multi-sensor data fusion on a mobile industrial vehicle. The system has a sensing processing system with a LiDAR and camera sensors, and a multi-processor module responsive to the different sensors. The sensing processing system fuses the different sensor data to locate the reflective beacons. A model predictive controller on the vehicle determines possible control solutions where each defines a threshold allowable speed for the vehicle at discrete moments based upon an estimated path to a breaching point projected from the reflective beacons, and then identifies an optimal one of the control solutions based upon a performance cost function and associated with an optimal threshold allowable speed. The system has a vehicle actuator configured to respond and alter vehicle movement to avoid a collision when the vehicle exceeds the optimal threshold allowable speed.
    Type: Grant
    Filed: February 26, 2019
    Date of Patent: September 1, 2020
    Assignee: FEDEX CORPORATE SERVICES, INC.
    Inventors: John E. Ball, Reuben F. Burch, V, Lucas D. Cagle, Collin S. Davenport, James R. Gafford, Tyler J. Hannis, Andrew R. Hegman, Andrew M. LeClair, Yucheng Liu, Michael S. Mazzola, Howard G. McKinney, Tasmia Reza, Jian Shi, Pan Wei, Dennison W. Iacomini
  • Publication number: 20190265714
    Abstract: Enhanced systems and methods for collision avoidance of a high value asset with reflective beacons around it using multi-sensor data fusion on a mobile industrial vehicle. The system has a sensing processing system with a LiDAR and camera sensors, and a multi-processor module responsive to the different sensors. The sensing processing system fuses the different sensor data to locate the reflective beacons. A model predictive controller on the vehicle determines possible control solutions where each defines a threshold allowable speed for the vehicle at discrete moments based upon an estimated path to a breaching point projected from the reflective beacons, and then identifies an optimal one of the control solutions based upon a performance cost function and associated with an optimal threshold allowable speed. The system has a vehicle actuator configured to respond and alter vehicle movement to avoid a collision when the vehicle exceeds the optimal threshold allowable speed.
    Type: Application
    Filed: February 26, 2019
    Publication date: August 29, 2019
    Inventors: John E. Ball, Reuben F. Burch, V, Lucas D. Cagle, Collin S. Davenport, James R. Gafford, Tyler J. Hannis, Andrew R. Hegman, Andrew M. LeClair, Yucheng Liu, Michael S. Mazzola, Howard G. McKinney, Tasmia Reza, Jian Shi, Pan Wei, Dennison W. Iacomini
  • Publication number: 20180310370
    Abstract: A circuit for mitigating electric shock including an external impedance detection circuit and a test and holdoff circuit. The external impedance detection circuit detects a presence of an external impedance, such as by detecting a relative change in voltage from a startup condition and a test condition. The test and holdoff circuit inhibits operation of a power converter which delivers power to be consumed by a load. The startup condition is defined by mains power applied to the circuit with negligible power consumed by a load. The test condition is defined by non-zero power delivered to the load. According to another aspect, the external impedance detection circuit measures an input voltage using a high input power which is greater than a shock hazard threshold at a duration less than a threshold time duration and determines the presence of the external impedance based on low pass filters having different time constants.
    Type: Application
    Filed: April 25, 2017
    Publication date: October 25, 2018
    Inventors: Jeremiah A. Heilman, John M. Davenport
  • Patent number: 9557044
    Abstract: An LED lamp has dual modes of operation from fluorescent lamp fixtures. A first circuit powers at least one LED in a first mode of operation when first and second power pins at a first end of the lamp are inserted into power contacts of the fixture that are directly connected to power mains. A second circuit powers at least one LED in a second mode of operation when the second power pin at the first end of the lamp and a third power pin at a second end of the lamp are inserted into power contacts of a fixture powered from an electronic ballast. First and second conduction control means permit the second circuit to power at least one LED during the second mode of operation.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: January 31, 2017
    Assignee: Energy Focus, Inc.
    Inventors: John M. Davenport, David Bina, Jeremiah Heilman
  • Publication number: 20160109070
    Abstract: An LED lamp has dual modes of operation from fluorescent lamp fixtures. A first circuit powers at least one LED in a first mode of operation when first and second power pins at a first end of the lamp are inserted into power contacts of the fixture that are directly connected to power mains. A second circuit powers at least one LED in a second mode of operation when the second power pin at the first end of the lamp and a third power pin at a second end of the lamp are inserted into power contacts of a fixture powered from an electronic ballast. First and second conduction control means permit the second circuit to power at least one LED during the second mode of operation.
    Type: Application
    Filed: May 1, 2015
    Publication date: April 21, 2016
    Applicant: Energy Focus, Inc.
    Inventors: John M. Davenport, David Bina, Jeremiah Heilman
  • Publication number: 20160113076
    Abstract: An LED lamp has dual modes of operation from fluorescent lamp fixtures. A first circuit powers at least one LED in a first mode of operation when first and second power connector pins at a first end of the lamp are inserted into power receptacles of the fixture that are directly connected to power mains. A second circuit powers at least one LED in a second mode of operation when the second power connector pin at the first end of the lamp and a third power connector pin at a second end of the lamp are inserted into power receptacles of a fixture powered from an electronic ballast. First and second conduction control means permit the second circuit to power at least one LED during the second mode of operation.
    Type: Application
    Filed: November 26, 2014
    Publication date: April 21, 2016
    Applicant: ENERGY FOCUS, INC.
    Inventors: John M. Davenport, David Bina, Jeremiah Heilman
  • Patent number: 8956006
    Abstract: An elongated LED lamp suitable for replacing a fluorescent lamp in a lamp fixture comprises a chassis having a first chassis end with two electrodes adapted to be respectively coupled to two electrodes in the lamp fixture supplying AC power, and a second chassis end. A light source depends from the chassis. A power regulating circuit is mounted to the chassis and is coupled to the two electrodes for providing DC power to the first light source. A first light collector conditions the light it collects light from the first light source for TIR propagation within a side-light distribution arrangement. An elongated side-light distribution portion depends from the chassis and receives light exiting the first light collector. Light-extraction structure extract light from the side of the first portion, along a length of the first portion, in a different direction from the direction of light received from the first light collector.
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: February 17, 2015
    Assignee: Energy Focus, Inc.
    Inventors: Roger F. Buelow, Laszlo A. Takacs, Keith D. Kazenski, Chris H. Jenson, Joseph G. Kaveski, John M. Davenport
  • Patent number: 8870428
    Abstract: An elongated LED lighting arrangement comprises an elongated fiberoptic light pipe having an exteriorly facing sidewall between its ends. The light pipe is constructed to promote TIR of light between the ends. A first LED light source is tuned to efficiently provide light within a wavelength range to the pipe. Light-extracting means are applied along the light pipe along the main path of TIR light propagation, and comprise down-converting means tuned to efficiently convert light rays from the LED light source within the wavelength range to lower-energy light rays at respectively longer wavelengths and light-scattering means for extracting from the pipe some light rays within the wavelength range without changing the wavelengths of the foregoing light. The light emitted by the down-converting means and the light-scattering means intermix to produce light, the majority of which has a composite color determined by the foregoing light emitted and the foregoing light extracted.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: October 28, 2014
    Assignee: Energy Focus, Inc.
    Inventors: Blair L. Unger, Gregory P. Frankiewicz, Joseph G. Kaveski, Roger F. Buelow, II, John M. Davenport
  • Publication number: 20130343079
    Abstract: An elongated LED lighting arrangement comprises an elongated fiberoptic light pipe having an exteriorly facing sidewall between its ends. The light pipe is constructed to promote TIR of light between the ends. A first LED light source is tuned to efficiently provide light within a wavelength range to the pipe. Light-extracting means are applied along the light pipe along the main path of TIR light propagation, and comprise down-converting means tuned to efficiently convert light rays from the LED light source within the wavelength range to lower-energy light rays at respectively longer wavelengths and light-scattering means for extracting from the pipe some light rays within the wavelength range without changing the wavelengths of the foregoing light. The light emitted by the down-converting means and the light-scattering means intermix to produce light, the majority of which has a composite color determined by the foregoing light emitted and the foregoing light extracted.
    Type: Application
    Filed: June 20, 2012
    Publication date: December 26, 2013
    Applicant: ENERGY FOCUS, INC.
    Inventors: Blair L. Unger, Gregory P. Frankiewicz, Joseph G. Kaveski, Roger F. Buelow, II, John M. Davenport
  • Patent number: 8348488
    Abstract: Lighted refrigerated display case with remote light source comprises a closed container with an interior of the container refrigerated to a temperature below 7 C. The container is thermally insulated from ambient, having internal and external walls. A solid fiber optic luminaire is at least partially mounted within the container, having an elongated side-light emitting portion for emitting light from the side of the luminaire onto contents in an interior of the display case. The side-light emitting portion comprises an extractor of light arranged to preferentially extract light from the luminaire and direct the light in at least one radial direction along the length of the side-light emitting portion to at least one target area of said contents along a longitudinal axis of the side-light emitting portion. A light-delivery system provides light to the fiber optic luminaire, having a light source mounted remotely from the interior of the container.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: January 8, 2013
    Assignee: Energy Focus, Inc.
    Inventors: Roger F. Buelow, II, John M. Davenport, William J. Cassarly, Thomas L. R. Davenport, Gregory P. Frankiewicz, Chris H. Jenson, Robert H. Caywood
  • Publication number: 20110038145
    Abstract: Disclosed is an LED fixture with passive cooling. The fixture includes a plurality of elongated tubes, each containing an array of LEDs mounted on a respective first surface or surfaces of one or more circuit boards. A frame mounts to a building structure and holds the ends of the tubes. Each tube is sufficiently spaced from any adjacent tube and from any other structure of the frame, and the frame is sufficiently open at the top and bottom, whereby heat from the tubes is capable of being dissipated merely by passive thermal transfer into an air flow created by the heat of the tubes, which air flow moves from beneath the tubes to above the tubes.
    Type: Application
    Filed: August 11, 2010
    Publication date: February 17, 2011
    Applicant: Energy Focus, Inc.
    Inventors: John M. Davenport, Joseph G. Kaveski, Jeremias A. Martins
  • Patent number: 7588342
    Abstract: Lighted refrigerated display case with remote light source comprises a closed container with an interior of the container refrigerated to a temperature below 7 C. The container is thermally insulated from ambient, having internal and external walls. A solid fiber optic luminaire is at least partially mounted within the container, having an elongated side-light emitting portion for emitting light from the side of the luminaire onto contents in an interior of the display case. The side-light emitting portion comprises an extractor of light arranged to preferentially extract light from the luminaire and direct the light in at least one radial direction along the length of the side-light emitting portion to at least one target area of said contents along a longitudinal axis of the side-light emitting portion. A light-delivery system provides light to the fiber optic luminaire, having a light source mounted remotely from the interior of the container.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: September 15, 2009
    Assignees: Energy Focus, Inc., Optical Research Associates
    Inventors: Roger F. Buelow, II, John M. Davenport, William J. Cassarly, Thomas L. R. Davenport, Gregory P. Frankiewicz, Chris H. Jenson, Robert H. Caywood
  • Patent number: 7549783
    Abstract: Luminaire with directional side-light extraction comprises a light pipe with a light-carrying core, and with a light-extraction structure along a first longitudinal side of the luminaire, confined to a radial swath of the luminaire, along the longitudinal axis of the luminaire, of substantially less than 180°. The second end of the light pipe has light-saving means for directing saved light from the second end towards the first end. The light-extraction means is adjustable to accommodate angular distributions of light from various light sources.
    Type: Grant
    Filed: April 5, 2006
    Date of Patent: June 23, 2009
    Assignees: Energy Focus, Inc., Optical Research Associates
    Inventors: William J. Cassarly, Thomas L. R. Davenport, John M. Davenport, Chris H. Jenson
  • Publication number: 20080144330
    Abstract: A light pipe with directional side-light extraction comprises a light pipe and light-extraction structure applied to the light pipe over only a part of the cross-sectional perimeter of the light pipe and over an active section of the length of the light pipe in which directional side lighting is desired. The light-extraction structure comprises any of (i) material, other than a light-carrying portion of the light pipe or any fluoropolymer cladding on the light-carrying portion, including light-scattering material, (ii) surfaces treated to have light-scattering properties, and (iii) material with a reflective property. The foregoing light pipe eliminates the need for using a reflector, as with fluorescent lamps, by extracting the light only in the desired direction, towards a target area to be illuminated. Other embodiments of the invention promote uniformity in side light emission from a light pipe.
    Type: Application
    Filed: February 27, 2008
    Publication date: June 19, 2008
    Inventors: Roger F. Buelow, John M. Davenport, Chris H. Jenson
  • Patent number: 7374313
    Abstract: A luminaire with improved lateral illuminance control comprising a light pipe with a longitudinal center is disclosed. A light-extraction means applied to a radial swath of the light pipe has a longitudinal portion having dimension along its length, centered about a slice on the light pipe longitudinally; said slice being orthogonal to the longitudinal center and located in a propagation plane through which light propagates to a virtual target area intersecting the propagation plane. The light pipe intervenes between the radial swath and the target area. A first average efficiency point of the light-extraction means corresponds to the minimum distance to the target area being at least approximately 20% less than a respective, second average efficiency point corresponding to a respective maximum distance to such area. The light-extraction means efficiency varies from the first average efficiency point to the second average efficiency point though more than one non-zero value.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: May 20, 2008
    Assignees: Energy Focus, Inc., Optical Research Associates
    Inventors: William J. Cassarly, Thomas L. R. Davenport, John M. Davenport, Chris H. Jenson
  • Publication number: 20080050087
    Abstract: Fiberoptic luminaire with scattering and specular side-light extractor patterns comprises a fiberoptic light pipe with elongated side-light emitting portion. Such portion illuminates a target area with a scattering, and a specular, light extractor pattern. The extractor patterns are arranged to extract light from the side-light emitting portion over a radial angle, orthogonal to said main axis, of less than 180°. The scattering extractor pattern alone may provide greater than 50% of light on the target area, and light extracted by the specular extractor pattern alone may produce an illuminance on a selected portion of the target area that is greater than 5% of the maximum illuminance produced on the target area by the scattering extractor pattern. Furthermore, the scattering extractor pattern may comprise a Lambertian type of extractor pattern. Each specular extractor pattern may comprise a notch having main faces parallel to within 10° of each other.
    Type: Application
    Filed: August 23, 2006
    Publication date: February 28, 2008
    Inventors: Roger F. Buelow, William J. Cassarly, Thomas L.R. Davenport, John M. Davenport, Chris H. Jenson
  • Patent number: 7330632
    Abstract: Fiberoptic luminaire with scattering and specular side-light extractor patterns comprises a fiberoptic light pipe with elongated side-fight emitting portion. Such portion illuminates a target area with a scattering, and a specular, light extractor pattern. The extractor patterns are arranged to extract light from the side-light emitting portion over a radial angle, orthogonal to said main axis, of less than 180°. The scattering extractor pattern atone may provide greater than 50% of light on the target area, and light extracted by the specular extractor pattern alone may produce an illuminance on a selected portion of the target area that is greater than 5% of the maximum illuminance produced on the target area by the scattering extractor pattern. Furthermore, the scattering extractor pattern may comprise a Lambertian type of extractor pattern. Each specular extractor pattern may comprise a notch having main faces parallel to within 10° of each other.
    Type: Grant
    Filed: August 23, 2006
    Date of Patent: February 12, 2008
    Assignees: Energy Focus, Inc., Optical Research Associates
    Inventors: Roger F. Buelow, II, William J. Cassarly, Thomas L. R. Davenport, John M. Davenport, Chris H. Jenson
  • Patent number: 7220035
    Abstract: An illumination system for a video-imaging device has a light source and a collector of light from the light source. The collector is formed according to the principles of non-imaging optics and receives a portion of the light from the light source. The collector is configured to reduce the angular distribution of the collected light from the light source to match the requirements of a digital pixelation device.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: May 22, 2007
    Assignee: Fiberstars, Inc.
    Inventors: Roger F. Buelow, II, Wayne R. Hellman, Juris Sulcs, John M. Davenport, Raymond A. Buchina, Gregory P. Frankiewicz
  • Patent number: 7198398
    Abstract: An adjustable-aim light pipe fixture, comprising a generally spherical eyeball for receiving an end of a light pipe is disclosed. The eyeball has a longitudinal axis coincident with a longitudinal axis of that portion of the light pipe that is received in the eyeball. A socket holds the eyeball. The socket comprises a first retainer ring and a second retainer ring. Each retainer ring has an interior surface with contact points to an outer surface of the eyeball. The first and second retainer rings are oriented with respect to each other so as to hold the eyeball in a fixed position when the first and second rings are pressed towards each other. Clamping structure clamps the first and second rings against each other in such manner as to hold the eyeball in fixed relation to the first retainer ring.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: April 3, 2007
    Assignee: Fiberstars, Inc.
    Inventors: Roger F. Buelow, II, John M. Davenport, Gregory P. Frankiewicz, Dave Bina