Patents by Inventor Steven D. Lester

Steven D. Lester 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: 7993943
    Abstract: A light-emitting device and the method for making the same are disclosed. The device includes a substrate, a light-emitting structure and a light scattering layer. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The light scattering layer includes a GaN crystalline layer characterized by an N-face surface. The N-face surface includes features that scatter light of the predetermined wavelength. The light-emitting structure is between the N-face surface and the substrate.
    Type: Grant
    Filed: January 18, 2010
    Date of Patent: August 9, 2011
    Assignee: Bridgelux, Inc.
    Inventor: Steven D. Lester
  • Publication number: 20110182064
    Abstract: A light source and method for making the same are disclosed. The light source includes a plurality of Segmented LEDs connected in parallel to a power bus and a controller. The power bus accepts a variable number of Segmented LEDs. The controller receives AC power and provides a power signal on the power bus. Each Segmented LED is characterized by a driving voltage that is greater than 3 times the driving voltage of a conventional LED fabricated in the same material system as the Segmented LED. The number of Segmented LEDs in the light source is chosen to compensate for variations in the light output of individual Segmented LEDs introduced by the manufacturing process. In another aspect of the invention, the number of Segmented LEDs connected to the power bus can be altered after the light source is assembled.
    Type: Application
    Filed: April 5, 2011
    Publication date: July 28, 2011
    Inventors: Ghulam Hasnain, Syn-Yem Hu, Steven D. Lester
  • Patent number: 7982409
    Abstract: A light source and method for making the same are disclosed. The light source includes a plurality of Segmented LEDs connected in parallel to a power bus and a controller. The power bus accepts a variable number of Segmented LEDs. The controller receives AC power and provides a power signal on the power bus. Each Segmented LED is characterized by a driving voltage that is greater than 3 times the driving voltage of a conventional LED fabricated in the same material system as the Segmented LED. The number of Segmented LEDs in the light source is chosen to compensate for variations in the light output of individual Segmented LEDs introduced by the manufacturing process. In another aspect of the invention, the number of Segmented LEDs connected to the power bus can be altered after the light source is assembled.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: July 19, 2011
    Assignee: Bridgelux, Inc.
    Inventors: Ghulam Hasnain, Syn-Yem Hu, Steven D. Lester
  • Patent number: 7897992
    Abstract: An electrode structure is disclosed for enhancing the brightness and/or efficiency of an LED. The electrode structure can have a metal electrode and an optically transmissive thick dielectric material formed intermediate the electrode and a light emitting semiconductor material. The electrode and the thick dielectric cooperate to reflect light from the semiconductor material back into the semiconductor so as to enhance the likelihood of the light ultimately being transmitted from the semiconductor material. Such LED can have enhanced utility and can be suitable for uses such as general illumination.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: March 1, 2011
    Assignee: Bridgelux, Inc.
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Publication number: 20110024782
    Abstract: An electrode structure is disclosed for enhancing the brightness and/or efficiency of an LED. The electrode structure can have a metal electrode and an dielectric material formed intermediate the electrode and a light emitting semiconductor material. Electrical continuity between the semiconductor material and the metal electrode is provided by an optically transmissive ohmic contact layer, such as a layer of Indium Tin Oxide. The metal electrode thus can be physically separated from the semiconductor material by one or more of the dielectric material and the ohmic contact layer. The dielectric layer can increase total internal reflection of light at the interface between the semiconductor and the dielectric layer, which can reduce absorption of light by the electrode. Such LED can have enhanced utility and can be suitable for uses such as general illumination.
    Type: Application
    Filed: September 22, 2010
    Publication date: February 3, 2011
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Publication number: 20110006332
    Abstract: Semiconductor devices in which one or more LEDs are formed include a dielectric region formed on a n/p region of the semiconductor, and that a metallic electrode can be formed on (at least partially on) the region of dielectric material. A transparent layer of a material such as Indium Tin Oxide can be used to make ohmic contact between the semiconductor and the metallic electrode, as the metallic electrode is separated from physical contact with the semiconductor by one or more of the dielectric material and the transparent ohmic contact layer (e.g., ITO layer). The dielectric material can enhance total internal reflection of light and reduce an amount of light that is absorbed by the metallic electrode.
    Type: Application
    Filed: September 22, 2010
    Publication date: January 13, 2011
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Publication number: 20110008918
    Abstract: Aspects concerning a method of making electrical contact to a region of semiconductor in which one or more LEDs are formed include that a dielectric region can be formed on a p region of the semiconductor, and that a metallic electrode can be formed on (at least partially on) the region of dielectric material. A transparent layer of a material such as Indium Tin Oxide can be used to make ohmic contact between the semiconductor and the metallic electrode, as the metallic electrode is separated from physical contact with the semiconductor by one or more of the dielectric material and the transparent ohmic contact layer (e.g., ITO layer). The dielectric material can enhance total internal reflection of light and reduce an amount of light that is absorbed by the metallic electrode.
    Type: Application
    Filed: September 22, 2010
    Publication date: January 13, 2011
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Patent number: 7847297
    Abstract: An ohmic contact in accordance with the invention includes a layer of p-type GaN-based material. A first layer of a group II-VI compound semiconductor is located adjacent to the layer of p-type GaN-based material. The ohmic contact further includes a metal layer that provides metal contact. A second layer of a different II-VI compound semiconductor is located adjacent to the metal layer.
    Type: Grant
    Filed: January 20, 2009
    Date of Patent: December 7, 2010
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Jeffrey N Miller, David P Bour, Virginia M Robbins, Steven D Lester
  • Patent number: 7791090
    Abstract: A device having a carrier, a light-emitting structure, and first and second electrodes is disclosed. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength in the active layer when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The first and second electrodes are bonded to the surfaces of the p-type and n-type GaN layers that are not adjacent to the active layer. The n-type GaN layer has a thickness less than 1.25 ?m. The carrier is bonded to the light emitting structure during the thinning of the n-type GaN layer. The thinned light-emitting structure can be transferred to a second carrier to provide a device that is analogous to conventional LEDs having contacts on the top surface of the LED.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: September 7, 2010
    Assignee: Bridgelux, Inc.
    Inventors: Steven D. Lester, Frank T. Shum
  • Publication number: 20100219431
    Abstract: A light source and method for making the same are disclosed. The light source includes a substrate and a light emitting structure that is deposited on the substrate. A barrier divides the light emitting structure into first and second segments that are electrically isolated from one another. A serial connection electrode connects the first segment in series with the second segment. A first blocking diode between the light emitting structure and the substrate prevents current from flowing between the light emitting structure and the substrate when the light emitting structure is emitting light. The barrier extends through the light emitting structure into the first blocking diode.
    Type: Application
    Filed: March 16, 2010
    Publication date: September 2, 2010
    Inventors: Ghulam Hasnain, Steven D. Lester, Syn-Yem Hu, Jeff Ramer
  • Publication number: 20100141175
    Abstract: A light source and method for making the same are disclosed. The light source includes a plurality of Segmented LEDs connected in parallel to a power bus and a controller. The power bus accepts a variable number of Segmented LEDs. The controller receives AC power and provides a power signal on the power bus. Each Segmented LED is characterized by a driving voltage that is greater than 3 times the driving voltage of a conventional LED fabricated in the same material system as the Segmented LED. The number of Segmented LEDs in the light source is chosen to compensate for variations in the light output of individual Segmented LEDs introduced by the manufacturing process. In another aspect of the invention, the number of Segmented LEDs connected to the power bus can be altered after the light source is assembled.
    Type: Application
    Filed: February 26, 2009
    Publication date: June 10, 2010
    Inventors: Ghulam Hasnain, Syn-Yem Hu, Steven D. Lester
  • Publication number: 20100133562
    Abstract: A light emitting device and method for making the same are disclosed. The device includes an active layer disposed between first and second layers. The first layer has top and bottom surfaces. The top surface includes a first material of a first conductivity type, including a plurality of pits in the substantially planar surface. The active layer overlies the top surface of the first layer and conforms to the top surface, the active layer generating light characterized by a wavelength when holes and electrons recombine therein. The second layer includes a second material of a second conductivity type, the second layer overlying the active layer and conforming to the active layer. The device can be constructed on a substrate having a lattice constant sufficiently different from that of the first material to give rise to dislocations in the first layer that are used to form the pits.
    Type: Application
    Filed: August 21, 2009
    Publication date: June 3, 2010
    Inventors: Ling Zhang, Steven D. Lester, Jeffrey C. Ramer
  • Publication number: 20100127276
    Abstract: A light-emitting device and the method for making the same are disclosed. The device includes a substrate, a light-emitting structure and a light scattering layer. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The light scattering layer includes a GaN crystalline layer characterized by an N-face surface. The N-face surface includes features that scatter light of the predetermined wavelength. The light-emitting structure is between the N-face surface and the substrate.
    Type: Application
    Filed: January 18, 2010
    Publication date: May 27, 2010
    Inventor: Steven D. Lester
  • Publication number: 20100059765
    Abstract: A light-emitting device includes first and second semiconductor layers and a light-emitting layer between the first and second semiconductor layers. The light-emitting device also includes an improved electrode structures.
    Type: Application
    Filed: May 27, 2009
    Publication date: March 11, 2010
    Applicant: Bridgelux, Inc.
    Inventors: Steven D. Lester, Chao-Kun Lin
  • Patent number: 7674639
    Abstract: A light-emitting device and the method for making the same are disclosed. The device includes a substrate, a light-emitting structure and a light scattering layer. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The light scattering layer includes a GaN crystalline layer characterized by an N-face surface. The N-face surface includes features that scatter light of the predetermined wavelength. The light-emitting structure is between the N-face surface and the substrate.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: March 9, 2010
    Assignee: Bridgelux, Inc
    Inventor: Steven D. Lester
  • Publication number: 20100046221
    Abstract: A light source and method for making the same are disclosed. The light source includes a housing, a drive assembly, and an LED. The housing has an interior compartment enclosed in an outer surface having a heat dissipating surface and first and second power terminals that are accessible from outside the interior compartment. The drive assembly is located in the interior compartment and electrically connected to the first and second power terminal. The LED is directly attached to the heat dissipating surface and electrically insulated therefrom, the LED having first and second LED power contacts. The housing has first and second housing power terminals disposed outside the housing, electrically isolated from the heat-dissipating surface, and connected to the drive assembly. A first conductor connects the first LED power contact to the first housing power terminal. A second conductor connects the LED second power contact to the second housing power terminal.
    Type: Application
    Filed: August 19, 2008
    Publication date: February 25, 2010
    Inventors: Jason Loomis Posselt, Michael Solomensky, Steven D. Lester, Ghulam Hasnain
  • Publication number: 20100032703
    Abstract: A light-emitting diode (LED) in accordance with the invention includes an edge-emitting LED stack having an external emitting surface from which light is emitted, and a reflective element that is located adjacent to at least one external surface of the LED stack other than the external emitting surface. The reflective element receives light that is generated inside the LED stack and reflects the received light back into the LED stack. At least a portion of the reflected light is then emitted from the external emitting surface.
    Type: Application
    Filed: October 15, 2009
    Publication date: February 11, 2010
    Applicant: Avago Technologies ECBU IP (Singapore) Pte. Ltd
    Inventors: Jeffrey N. Miller, Steven D. Lester, Virginia M. Robbins
  • Patent number: 7635874
    Abstract: A light-emitting diode (LED) in accordance with the invention includes an edge-emitting LED stack having an external emitting surface from which light is emitted, and a reflective element that is located adjacent to at least one external surface of the LED stack other than the external emitting surface. The reflective element receives light that is generated inside the LED stack and reflects the received light back into the LED stack. At least a portion of the reflected light is then emitted from the external emitting surface.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: December 22, 2009
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Jeffrey N. Miller, Steven D. Lester, Virginia M. Robbins
  • Patent number: 7622746
    Abstract: A semiconductor device emitting light about a predetermined wavelength comprising a structure comprising a plurality of layers, sometimes referred to as a stack, providing low resistance, high reflectivity and ohmic contacts to at least one semiconductor material.
    Type: Grant
    Filed: March 17, 2006
    Date of Patent: November 24, 2009
    Assignee: Bridgelux, Inc.
    Inventors: Steven D. Lester, Frank Shum, Chao-Kun Lin, William So, Qingwei Mo
  • Publication number: 20090261373
    Abstract: An electrode structure is disclosed for enhancing the brightness and/or efficiency of an LED. The electrode structure can have a metal electrode and an optically transmissive thick dielectric material formed intermediate the electrode and a light emitting semiconductor material. The electrode and the thick dielectric cooperate to reflect light from the semiconductor material back into the semiconductor so as to enhance the likelihood of the light ultimately being transmitted from the semiconductor material. Such LED can have enhanced utility and can be suitable for uses such as general illumination.
    Type: Application
    Filed: June 29, 2009
    Publication date: October 22, 2009
    Inventors: Frank T. Shum, William W. So, Steven D. Lester