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: 9324915
    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: Grant
    Filed: January 8, 2014
    Date of Patent: April 26, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Steven D. Lester, Chao-Kun Lin
  • Publication number: 20150382410
    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: June 26, 2015
    Publication date: December 31, 2015
    Inventors: Ghulam HASNAIN, Syn-Yem HU, Steven D. LESTER
  • Publication number: 20150380609
    Abstract: A laser apparatus may comprise: a substrate having a first surface and a second surface opposite to the first surface; a light emitting region formed on the first surface of the first substrate, the light emitting region including a p-type semiconductor layer and an n-type semiconductor layer; a p-contact layer formed on the p-type semiconductor layer; an n-contact layer formed on the n-type semiconductor layer; a sub-mount formed on the p-contact layer and the n-contact layer, the sub-mount including a first patterned dielectric coating layer formed on the p-contact layer and a reflector formed on the patterned dielectric coating layer.
    Type: Application
    Filed: September 2, 2015
    Publication date: December 31, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Steven D. Lester
  • Publication number: 20150340554
    Abstract: A light source and method for making the same are disclosed. The light source includes a conducting substrate, and a light emitting structure that is divided into segments. The light emitting structure includes a first layer of semiconductor material of a first conductivity type deposited on the substrate, an active layer overlying the first layer, and a second layer of semiconductor material of an opposite conductivity type from the first conductivity type overlying the active layer. 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 layer in the first segment to the second layer in the second segment. A power contact is electrically connected to the second layer in the first segment, and a second power contact electrically connected to the first layer in the second segment.
    Type: Application
    Filed: July 30, 2015
    Publication date: November 26, 2015
    Inventors: Steven D. Lester, Chih-Wei Chuang
  • Patent number: 9123853
    Abstract: A light source and method for making the same are disclosed. The light source includes a conducting substrate, and a light emitting structure that is divided into segments. The light emitting structure includes a first layer of semiconductor material of a first conductivity type deposited on the substrate, an active layer overlying the first layer, and a second layer of semiconductor material of an opposite conductivity type from the first conductivity type overlying the active layer. 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 layer in the first segment to the second layer in the second segment. A power contact is electrically connected to the second layer in the first segment, and a second power contact electrically connected to the first layer in the second segment.
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: September 1, 2015
    Assignee: Manutius IP, Inc.
    Inventors: Steven D. Lester, Chih-Wei Chuang
  • Publication number: 20150228860
    Abstract: Aspects include Light Emitting Diodes that have a GaN-based light emitting region and a metallic electrode. The metallic electrode can be physically separated from the GaN-based light emitted region by a layer of porous dielectric, which provides a reflecting region between at least a portion of the metallic electrode and the GaN-based light emitting region.
    Type: Application
    Filed: April 22, 2015
    Publication date: August 13, 2015
    Inventors: Frank T. SHUM, William W. SO, Steven D. LESTER
  • Patent number: 9105815
    Abstract: Aspects include Light Emitting Diodes that have a GaN-based light emitting region and a metallic electrode. The metallic electrode can be physically separated from the GaN-based light emitted region by a layer of porous dielectric, which provides a reflecting region between at least a portion of the metallic electrode and the GaN-based light emitting region.
    Type: Grant
    Filed: November 11, 2012
    Date of Patent: August 11, 2015
    Assignee: BRIDGELUX, INC.
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Patent number: 9099613
    Abstract: Aspects include Light Emitting Diodes that have a GaN-based light emitting region and a metallic electrode. The metallic electrode can be physically separated from the GaN-based light emitted region by a layer of porous dielectric, which provides a reflecting region between at least a portion of the metallic electrode and the GaN-based light emitting region.
    Type: Grant
    Filed: August 11, 2014
    Date of Patent: August 4, 2015
    Assignee: BRIDGELUX, INC.
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Patent number: 9082892
    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: January 30, 2013
    Date of Patent: July 14, 2015
    Assignee: Manulius IP, Inc.
    Inventors: Steven D. Lester, Frank T. Shum
  • Publication number: 20150125974
    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: Application
    Filed: January 30, 2013
    Publication date: May 7, 2015
    Applicant: MANUTIUS IP, INC.
    Inventors: Steven D. Lester, Frank T. Shum
  • Publication number: 20140346554
    Abstract: Aspects include Light Emitting Diodes that have a GaN-based light emitting region and a metallic electrode. The metallic electrode can be physically separated from the GaN-based light emitted region by a layer of porous dielectric, which provides a reflecting region between at least a portion of the metallic electrode and the GaN-based light emitting region.
    Type: Application
    Filed: August 11, 2014
    Publication date: November 27, 2014
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Publication number: 20140213000
    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: Application
    Filed: January 30, 2013
    Publication date: July 31, 2014
    Applicant: TOSHIBA TECHNO CENTER INC.
    Inventors: Steven D. Lester, Frank T. Shum
  • Patent number: 8729580
    Abstract: A light emitting device based on a AlInGaN materials system wherein a coating is used to improve the extraction of light from a device. A coating has a very low optical loss and an index of refraction greater than 2. In a preferred embodiment the coating is made from Ta2O5, Nb2O5, TiO2, or SiC and has a thickness between about 0.01 and 10 microns. A surface of a coating material may be textured or shaped to increase its surface area and improve light extraction. A surface of the coating material can also be shaped to engineer the directionality of light escaping the layer. A coating can be applied directly to a surface or multiple surfaces of a light emitting device or can be applied onto a contact material. A coating may also serve as a passivation or protection layer for a device.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: May 20, 2014
    Assignee: Toshiba Techno Center, Inc.
    Inventor: Steven D. Lester
  • Publication number: 20140124806
    Abstract: An AlInGaN light emitting device having a coating is used to improve the extraction of light from a device. A coating has a very low optical loss and an index of refraction greater than 2, preferably having an index of refraction close to or greater than the index of refraction of GaN. The coating can be made from Ta2O5, Nb2O5, TiO2, or SiC and has can have a thickness between 0.01 and 10 microns. A surface of the coating material may be textured or shaped to increase its surface area and improve light extraction. A coating can be applied directly to one or multiple surfaces of the light emitting device or can be applied onto a contact material and can serve as a passivation or as a protection layer for a device.
    Type: Application
    Filed: October 27, 2009
    Publication date: May 8, 2014
    Applicant: BRIDGELUX, INC.
    Inventor: Steven D. Lester
  • Publication number: 20140117404
    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: January 8, 2014
    Publication date: May 1, 2014
    Applicant: TOSHIBA TECHNO CENTER INC.
    Inventors: Steven D. LESTER, Chao-Kun LIN
  • Publication number: 20140054638
    Abstract: Light emitting devices comprise a light emitting component, such as a GaN LED having active material layers supported by a Silicon substrate, which can be a growth substrate, or attached. Phosphor(s) can be disposed relative to the light emitting component to absorb a primary emission, and produce a secondary emission that can be relatively tuned or selected so that their combination produces light of a desired spectrum, such as light appearing white. The Silicon substrate has exposed sidewalls, which can be angled, with respect to planar surfaces of the substrate, and a light reflecting material, such as a diffusely reflective material coats the sidewalls. The reflective material can be opaque to the primary and secondary emissions. If other exposed portions of the Silicon substrate exist and are exposed to primary or secondary light, these other exposed portions can be coated with such light reflecting material.
    Type: Application
    Filed: March 11, 2013
    Publication date: February 27, 2014
    Applicant: TOSHIBA TECHNO CENTER, INC.
    Inventors: Steven D. Lester, Long Yang, Chao-Kun Lin
  • Patent number: 8637891
    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: Grant
    Filed: May 27, 2009
    Date of Patent: January 28, 2014
    Assignee: Toshiba Techno Center Inc.
    Inventors: Steven D. Lester, Chao-Kun Lin
  • Publication number: 20130313519
    Abstract: A light source and method for making the same are disclosed. The light source includes a conducting substrate, and a light emitting structure that is divided into segments. The light emitting structure includes a first layer of semiconductor material of a first conductivity type deposited on the substrate, an active layer overlying the first layer, and a second layer of semiconductor material of an opposite conductivity type from the first conductivity type overlying the active layer. 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 layer in the first segment to the second layer in the second segment. A power contact is electrically connected to the second layer in the first segment, and a second power contact electrically connected to the first layer in the second segment.
    Type: Application
    Filed: August 5, 2013
    Publication date: November 28, 2013
    Applicant: TOSHIBA TECHNO CENTER INC.
    Inventors: Steven D. Lester, CHIH-WEI CHUANG
  • Patent number: 8581267
    Abstract: A light source and method for making the same are disclosed. The light source includes a conducting substrate, and a light emitting structure that is divided into segments. The light emitting structure includes a first layer of semiconductor material of a first conductivity type deposited on the substrate, an active layer overlying the first layer, and a second layer of semiconductor material of an opposite conductivity type from the first conductivity type overlying the active layer. 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 layer in the first segment to the second layer in the second segment. A power contact is electrically connected to the second layer in the first segment, and a second power contact electrically connected to the first layer in the second segment.
    Type: Grant
    Filed: November 9, 2011
    Date of Patent: November 12, 2013
    Assignee: Toshiba Techno Center Inc.
    Inventors: Steven D. Lester, Chih-Wei Chuang
  • Patent number: 8552465
    Abstract: A device and method for making the same are disclosed. The device includes a substrate having a first TEC, a stress relief layer overlying the substrate, and crystalline cap layer. The crystalline cap layer overlies the stress relief layer. The cap layer has a second TEC different from the first TEC. The stress relief layer includes an amorphous material that relieves stress between the crystalline substrate and the cap layer arising from differences in the first and second TECs at a growth temperature at which layers are grown epitaxially on the cap layer. The device can be used to construct various semiconductor devices including GaN LEDs that are fabricated on silicon or SiC wafers. The stress relief layer is generated by converting a layer of precursor material on the substrate after the cap layer has been grown to a stress-relief layer.
    Type: Grant
    Filed: November 9, 2011
    Date of Patent: October 8, 2013
    Assignee: Toshiba Techno Center Inc.
    Inventor: Steven D. Lester