Patents by Inventor Everett Bradford

Everett Bradford 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: 20240074031
    Abstract: The present disclosure relates to a textured metal core printed circuit board (MCPCB) that has improved thermal dissipation characteristics to remove thermal energy generated by solid-state lighting devices including light-emitting diodes (LEDs) and other electronic components. The textured MCPCB surface can increase the surface area of the MCPCB surface in order to more effectively radiate or conduct thermal energy to the surroundings. In one embodiment, the textured surface of the MCPCB can be exposed to the air without the need for a separate heatsink component. The textured MCPCB surface can machined to form grooves on the surface of the MCPCB in order to channel air and increase the surface area. In an embodiment, the textured MCPCB surface can be etched to increase the surface area of the textured MCPCB surface on a microscopic scale and to induce turbulent air patterns which can improve the dissipation of thermal energy.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 29, 2024
    Inventor: Everett Bradford
  • Patent number: 10499481
    Abstract: The lighting device includes a LED board that supports an LED. A communication interface is provided with the LED board. At least one of a dimming control command and a color control command is received at the communication interface on then LED board. The communication interface sends the received control signals to the LED board controller. If the control signal is a dimming control command the LED board controller transmits a driver control signal to the LED driver. The driver adjusts the current delivered to the LED board based on the driver control signal. If a color control command is received the LED board controller adjusts the color of the emitted light by selectively operating different color LEDs as programmed in the LED board controller.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: December 3, 2019
    Assignee: IDEAL Industries Lighting LLC
    Inventor: Everett Bradford
  • Publication number: 20190364641
    Abstract: The lighting device includes a LED board that supports an LED. A communication interface is provided with the LED board. At least one of a dimming control command and a color control command is received at the communication interface on then LED board. The communication interface sends the received control signals to the LED board controller. If the control signal is a dimming control command the LED board controller transmits a driver control signal to the LED driver. The driver adjusts the current delivered to the LED board based on the driver control signal. If a color control command is received the LED board controller adjusts the color of the emitted light by selectively operating different color LEDs as programmed in the LED board controller.
    Type: Application
    Filed: May 24, 2018
    Publication date: November 28, 2019
    Inventor: Everett Bradford
  • Patent number: 10165635
    Abstract: A controller in a solid state luminaire implements a nested control loop to drive multiple, parallel-connected, heterogeneous strings of series-connected LEDs using a constant current power supply. The current through each string is independently controlled by a current regulator in series with the LEDs. An inner (current) control loop alters the relative drive strength of each LED string, to achieve desired luminous characteristics, such as CRI, CCT, and the like. An outer (voltage) control loop monitors the output voltage of the power supply, and the total current drawn. The outer control loop adjusts a gain factor applied to the control signals for each current regulator, to control the total current drawn—while maintaining the relative ratios of drive strength between the strings—so as to maintain the power supply output voltage at a substantially constant value.
    Type: Grant
    Filed: December 12, 2017
    Date of Patent: December 25, 2018
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 10021756
    Abstract: A lighting device employs at least one string of LEDs as a lighting source. The string of LEDs is coupled in series with a first switch, wherein the string of LEDs and the first switch are coupled between a power supply node and ground. During a normal operation mode, a system controller is configured to close the first switch to deliver a drive current to the string of LEDs from the power supply node. The system controller is further associated with a temperature sensor and is configured to detect an over-temperature condition based on information provided by the temperature sensor. Upon detecting the over-temperature condition, the system controller will open the first switch to stop the drive current from flowing through the string of LEDs.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: July 10, 2018
    Assignee: Cree, Inc.
    Inventors: Everett Bradford, John Perry
  • Patent number: 9756696
    Abstract: A configurable LED lighting system and its method of operation are disclosed. A lighting system or apparatus includes a string of LEDs, wherein specific LEDs are operable to emit different colors of light. The string includes a plurality of series-connected color segments. A shunt segment includes additional LEDs. The LED shunt segment is connected in parallel with at least one of the color segments. A controller is connected to the LED shunt segment to selectively balance drive current between the LED shunt segment and the color segment to which it is connected in parallel so that a color temperature of light is controllable by a processor. The diverted power still produces light and power is not wasted. The controller can use a polynomial equation or a look-up table to calculate color output values.
    Type: Grant
    Filed: October 17, 2016
    Date of Patent: September 5, 2017
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9713226
    Abstract: The present disclosure relates to a lighting device that employs at least one string of LEDs as a lighting source. The string of LEDs is coupled in series with a first semiconductor switch, wherein the string of LEDs and the first semiconductor switch are coupled between a power supply node and ground. During a period when the lighting device is powering up after being initially provided power by a power supply, the system controller is configured to monitor a drive current through the first string of LEDs and modulate a control signal provided to the first semiconductor switch based on the drive current to prevent the drive current from exceeding a maximum allowable drive current value for the first string of LEDs.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: July 18, 2017
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9705594
    Abstract: The disclosure relates to a lighting fixture, which includes an array of solid-state light sources that are configured to generate light for general illumination lighting purposes and control circuitry. A drive signal is used to drive solid-state light sources. The control circuitry is configured to use a control output to control the drive signal to at least one of the solid-state light sources. The control output is configured to control the drive signal to 1) set at least one characteristic of the light generated by the array of the solid-state light sources, and 2) modulate the light with data for transmission. The light is modulated such that any change in the at least one characteristic based on the light being modulated is anthropically imperceptible. The characteristic of the light generated by the array of solid-state light sources may include the intensity, color, color temperature and the like.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: July 11, 2017
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9648695
    Abstract: An apparatus includes a bus configured to be coupled to a controlled current source and at least one light emitting device coupled to the bus. The apparatus further includes a voltage regulator circuit configured to regulate a voltage at the bus and a current regulator circuit configured to control a current through the at least one light emitting device. In some embodiments, the current regulator circuit is used to control a color output of the apparatus.
    Type: Grant
    Filed: July 31, 2013
    Date of Patent: May 9, 2017
    Assignee: Cree, Inc.
    Inventors: Shawn Hill, Everett Bradford
  • Patent number: 9591707
    Abstract: A lighting device employs at least one string of LEDs as a lighting source. The string of LEDs may be coupled in series between a power supply node and ground. In order to accurately determine a drive current running through or drive voltage across the string of LEDs, the drive current through the string of LEDs or the drive voltage across the string of LEDs is sampled randomly or semi-randomly, and a moving average is determined from each one of the samples. By sampling the drive current through or drive voltage across the string of LEDs randomly or semi-randomly, inaccuracies due to synchronization of the sampling with interference in the drive current signal or the drive voltage signal are effectively prevented. Accordingly, an accurate measurement of the drive current through or the drive voltage across the string of LEDs may be obtained.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: March 7, 2017
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9549443
    Abstract: A lighting device employs an array of LEDs as a lighting source. The array of LEDs may be coupled in series between a power supply node and ground. In order to determine whether the input drive signal to the array of LEDs is a pulse width modulated (PWM) signal or a linear signal, the voltage across the string of LEDs is sampled and stored in a cyclical buffer. The variance of the samples stored in the cyclical buffer is then calculated and used to determine whether the input signal provided to the string of LEDs at the power supply node is a PWM signal or a linear signal. In one embodiment, the variance is compared to a predetermined threshold value to determine whether the input signal is a PWM signal or a linear signal.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: January 17, 2017
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9480115
    Abstract: Dynamic light emitting device (LED) lighting adjustment systems and related methods are disclosed. In one aspect, a method can receive, at an LED lighting fixture, a lighting adjustment signal corresponding to a target lighting level and determine a delta value that represents a difference between a current lighting level of the LED lighting fixture and the target lighting level and a step time value associated with the determined delta value. The method can further include adjusting the current lighting level of the LED lighting fixture to a new current lighting level for the duration of the step time value and repeating the determining and adjusting steps until the new current lighting level equals the target lighting level.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: October 25, 2016
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9388947
    Abstract: A lighting device includes one or more lumiphoric materials spatially segregated from one or more electrically activated (e.g., solid state) emitters and arranged to emit light toward a reflector for reflection of lumiphor-converted light emissions toward a light transmissive end of the lighting device. One or more adjustment elements may be arranged adjust position of the at least one lumiphoric material, and/or to adjust at least one of (a) position, (b) aim, and (c) focus, of the at least one electrically activated light emitting source.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: July 12, 2016
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Patent number: 9137873
    Abstract: The present disclosure relates to a lighting device that employs at least one string of LEDs as a lighting source. The string of LEDs is coupled in series with a first switch, wherein the string of LEDs and the first switch are coupled between a power supply node and ground. During a normal operation mode, a system controller is configured to operate the first switch to deliver a drive current to the string of LEDs from the power supply node. The system controller is associated with circuitry that allows the system controller to monitor the drive current and determine when an overcurrent condition occurs. Upon detecting the overcurrent condition, the system controller will open the first switch to stop the drive current from flowing through the string of LEDs.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: September 15, 2015
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Publication number: 20150115811
    Abstract: A lighting device employs an array of LEDs as a lighting source. The array of LEDs may be coupled in series between a power supply node and ground. In order to determine whether the input drive signal to the array of LEDs is a pulse width modulated (PWM) signal or a linear signal, the voltage across the string of LEDs is sampled and stored in a cyclical buffer. The variance of the samples stored in the cyclical buffer is then calculated and used to determine whether the input signal provided to the string of LEDs at the power supply node is a PWM signal or a linear signal. In one embodiment, the variance is compared to a predetermined threshold value to determine whether the input signal is a PWM signal or a linear signal.
    Type: Application
    Filed: October 25, 2013
    Publication date: April 30, 2015
    Applicant: Cree, Inc.
    Inventor: Everett Bradford
  • Publication number: 20150115816
    Abstract: A lighting device employs at least one string of LEDs as a lighting source. The string of LEDs may be coupled in series between a power supply node and ground. In order to accurately determine a drive current running through or drive voltage across the string of LEDs, the drive current through the string of LEDs or the drive voltage across the string of LEDs is sampled randomly or semi-randomly, and a moving average is determined from each one of the samples. By sampling the drive current through or drive voltage across the string of LEDs randomly or semi-randomly, inaccuracies due to synchronization of the sampling with interference in the drive current signal or the drive voltage signal are effectively prevented. Accordingly, an accurate measurement of the drive current through or the drive voltage across the string of LEDs may be obtained.
    Type: Application
    Filed: October 25, 2013
    Publication date: April 30, 2015
    Applicant: Cree, Inc.
    Inventor: Everett Bradford
  • Publication number: 20150035443
    Abstract: An apparatus includes a bus configured to be coupled to a controlled current source and at least one light emitting device coupled to the bus. The apparatus further includes a voltage regulator circuit configured to regulate a voltage at the bus and a current regulator circuit configured to control a current through the at least one light emitting device. The current regulator circuit may be used to control a color output of the apparatus.
    Type: Application
    Filed: July 31, 2013
    Publication date: February 5, 2015
    Applicant: Cree, Inc.
    Inventors: Shawn Hill, Everett Bradford
  • Patent number: 8890420
    Abstract: A lighting device includes a first array of LEDs, a temperature sensor, memory, and a system controller. The memory may include a first duty cycle offset and first curve information that defines a relationship between temperature and a duty cycle for driving at least one LED of the first array of LEDs. The system controller will determine a temperature based on information from the temperature sensor. Based on the temperature, the system controller will determine a first pre-calibrated duty cycle that corresponds to the temperature from the first curve information and then adjust the first pre-calibrated duty cycle with the first duty cycle offset to generate a first calibrated duty cycle. The LED is then driven with a first pulse width modulated signal having the first calibrated duty cycle.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: November 18, 2014
    Assignee: Cree, Inc.
    Inventor: Everett Bradford
  • Publication number: 20140270793
    Abstract: The disclosure relates to a lighting fixture, which includes an array of solid-state light sources that are configured to generate light for general illumination lighting purposes and control circuitry. A drive signal is used to drive solid-state light sources. The control circuitry is configured to use a control output to control the drive signal to at least one of the solid-state light sources. The control output is configured to control the drive signal to 1) set at least one characteristic of the light generated by the array of the solid-state light sources, and 2) modulate the light with data for transmission. The light is modulated such that any change in the at least one characteristic based on the light being modulated is anthropically imperceptible. The characteristic of the light generated by the array of solid-state light sources may include the intensity, color, color temperature and the like.
    Type: Application
    Filed: March 15, 2013
    Publication date: September 18, 2014
    Applicant: CREE, INC.
    Inventor: Everett Bradford
  • Patent number: 8836231
    Abstract: A modularized LED lamp is disclosed. Embodiments of the present invention provide an LED lamp in which digital and/or analog communication takes place between the LED module and the power supply unit (PSU) of the lamp. A controller in the LED module sends signals to the PSU, allowing separation of the two parts so that each part can be manufactured independently as opposed to being manufactured as a calibrated, matched pair. The LED module, by way of its controller, provides information to the PSU that allows the power supply to adjust its drive current appropriately. The PSU controller can also respond to operating temperature variations of the LEDs in order to provide thermal shutdown, brightness compensation, and other control if needed. In some embodiments, a controller in the PSU also responds to an external dimming input.
    Type: Grant
    Filed: August 26, 2011
    Date of Patent: September 16, 2014
    Assignee: Cree, Inc.
    Inventor: Everett Bradford