Patents by Inventor Bernd P. Keller
Bernd P. Keller 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).
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Patent number: 8508127Abstract: Solid state lighting devices include least one solid state emitter and multiple lumiphors, arranged to output aggregated emissions that include at least one short wavelength blue peak, at least one long wavelength blue (LWB) peak, at least one yellow and/or green peak, and at least one red and/or orange peak. Presence of long wavelength blue enhances color rendering. At least one solid state emitter may include a short wavelength blue LED, LWB LED, and/or UV LED. Multiple emitters may be provided. Resulting devices may provide CRI greater than 85, efficiency of greater than 50 lm/watt, and color stability in a range of ?u?v??0.008 over a temperature change of 75° C.Type: GrantFiled: March 9, 2010Date of Patent: August 13, 2013Assignee: Cree, Inc.Inventors: Gerald H. Negley, Antony Paul van de Ven, Bernd P. Keller, Ronan P. LeToquin, Peter Scott Andrews
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Patent number: 8410680Abstract: A multi-chip lighting emitting device (LED) lamp for providing white light includes a submount including first and second die mounting regions thereon. A first LED chip is mounted on the first die mounting region, and a second LED chip is mounted on the second die mounting region. The LED lamp is configured to emit light having a spectral distribution including at least four different color peaks to provide the white light. For example, a first conversion material may at least partially cover the first LED chip, and may be configured to absorb at least some of the light of the first color and re-emit light of a third color. In addition, a second conversion material may at least partially cover the first and/or second LED chips, and may be configured to absorb at least some of the light of the first and/or second colors and re-emit light of a fourth color. Related light fixtures and methods are also disclosed.Type: GrantFiled: November 5, 2010Date of Patent: April 2, 2013Assignee: Cree, Inc.Inventors: Nicholas W. Medendorp, Jr., Mark Terrence McClear, Bernd P. Keller, George R. Brandes, Ronan P. LeToquin
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Publication number: 20130020929Abstract: A green-shifted red solid state lighting device includes at least one green solid state light emitter arranged to stimulate emissions from at least one red lumiphor, arranged in combination with at least one blue solid state light emitter. Such device may be devoid of any yellow lumiphor arranged to be stimulated by a blue solid state light emitter. A green shifted red plus blue (GSR+B) lighting device exhibits reduced Stokes Shift losses as compared to a blue shifted yellow plus red (BSY+R) lighting device, with comparable color rendering performance and similar efficiency, enhanced color stability over a range of operating temperatures, and enhanced color rendering performance at higher correlated color temperatures. Additional solid state emitters and/or lumiphors may be provided.Type: ApplicationFiled: April 6, 2012Publication date: January 24, 2013Applicant: CREE, INC.Inventors: Antony Paul van de Ven, Gerald H. Negley, Ronan P. LeToquin, Bernd P. Keller, James Ibbetson
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Patent number: 8333631Abstract: Methods of forming a light emitting device package assembly include defining a chromaticity region in a two dimensional chromaticity space within a 10-step MacAdam ellipse of a target chromaticity point, and subdividing the defined chromaticity region into at least three chromaticity subregions, providing a plurality of light emitting devices that emit light having a chromaticity that falls within the defined chromaticity region, selecting at least three of the plurality of light emitting devices, wherein each of the three light emitting devices emits light from a different one of the chromaticity subregions. The at least three light emitting devices are selected from chromaticity subregions that are complementary relative to the target chromaticity point to at least one other chromaticity subregion from which a light emitting device is selected.Type: GrantFiled: July 19, 2010Date of Patent: December 18, 2012Assignee: Cree, Inc.Inventors: David Todd Emerson, Bernd P. Keller, Mark McOlear, Peter S. Andrews
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Patent number: 8324637Abstract: An LED made from a wide band gap semiconductor material and having a low resistance p-type confinement layer with a tunnel junction in a wide band gap semiconductor device is disclosed. A dissimilar material is placed at the tunnel junction where the material generates a natural dipole. This natural dipole is used to form a junction having a tunnel width that is smaller than such a width would be without the dissimilar material. A low resistance p-type confinement layer having a tunnel junction in a wide band gap semiconductor device may be fabricated by generating a polarization charge in the junction of the confinement layer, and forming a tunnel width in the junction that is smaller than the width would be without the polarization charge. Tunneling through the tunnel junction in the confinement layer may be enhanced by the addition of impurities within the junction. These impurities may form band gap states in the junction.Type: GrantFiled: May 18, 2010Date of Patent: December 4, 2012Assignee: Cree, Inc.Inventors: James P. Ibbetson, Bernd P. Keller, Umesh K. Mishra
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Publication number: 20120280261Abstract: A light emitting diode (LED) for achieving an asymmetric light output includes a multilayered structure comprising a p-n junction, where at least one layer of the multilayered structure comprises a surface configured to provide a peak emission in a direction away from a normal to a mounting surface, the surface being a top or bottom surface of the layer.Type: ApplicationFiled: May 4, 2011Publication date: November 8, 2012Applicant: Cree, Inc.Inventors: Eric J. Tarsa, Theodore D. Lowes, Bernd P. Keller
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Publication number: 20120199852Abstract: An LED component includes, according to a first embodiment, a monolithic substrate, an array of LED chips disposed on a surface of the substrate, and an optical lens overlying the LED chips and having a lens base attached to the substrate, where the LED chips are positioned to provide a peak emission shifted from a perpendicular centerline of the lens base. The LED component includes, according to a second embodiment, a monolithic substrate, an array of LED chips disposed on a surface of the substrate, and an array of optical lenses, each optical lens overlying at least one of the LED chips and having a lens base attached to the substrate, where at least one of the LED chips is positioned to provide a peak emission shifted from a perpendicular centerline of the respective lens base.Type: ApplicationFiled: February 4, 2011Publication date: August 9, 2012Applicant: CREE, INC.Inventors: Theodore D. Lowes, Eric J. Tarsa, Bernd P. Keller, David T. Emerson
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Publication number: 20120061702Abstract: A submount for mounting an LED chip includes a substrate, a die attach pad configured to receive an LED chip on an upper surface of the substrate, a first meniscus control feature on the substrate surrounding the die attach pad and defining a first encapsulant region of the upper surface of the substrate, and a second meniscus control feature on the substrate surrounding the first encapsulant region and defining a second encapsulant region of the upper surface of the substrate. The first and second meniscus control features may be substantially coplanar with the die attach pad. A packaged LED includes a submount as described above and further includes an LED chip on the die attach pad, a first encapsulant on the substrate within the first encapsulant region, and a second encapsulant on the substrate within the second encapsulant region and covering the first encapsulant. Method embodiments are also disclosed.Type: ApplicationFiled: May 31, 2011Publication date: March 15, 2012Inventors: Peter S. Andrews, Ban P. Loh, Nicholas W. Medendorp, JR., Bernd P. Keller
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Patent number: 8125137Abstract: A multi-chip lighting emitting device (LED) lamp for providing white light includes a submount including first and second die mounting regions thereon. A first LED chip is mounted on the first die mounting region, and a second LED chip is mounted on the second die mounting region. The LED lamp is configured to emit light having a spectral distribution including at least four different color peaks to provide the white light. For example, a first conversion material may at least partially cover the first LED chip, and may be configured to absorb at least some of the light of the first color and re-emit light of a third color. In addition, a second conversion material may at least partially cover the first and/or second LED chips, and may be configured to absorb at least some of the light of the first and/or second colors and re-emit light of a fourth color. Related light fixtures and methods are also discussed.Type: GrantFiled: May 2, 2007Date of Patent: February 28, 2012Assignee: Cree, Inc.Inventors: Nicholas W. Medendorp, Jr., Mark McClear, Bernd P. Keller, George R. Brandes, Ronan P. LeToquin
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Patent number: 8124957Abstract: A low resistance tunnel junction that uses a natural polarization dipole associated with dissimilar materials to align a conduction band to a valence band is disclosed. Aligning the conduction band to the valence band of the junction encourages tunneling across the junction. The tunneling is encouraged, because the dipole space charge bends the energy bands, and shortens a tunnel junction width charge carriers must traverse to tunnel across the junction. Placing impurities within or near the tunnel junction that may form deep states in the junction may also encourage tunneling in a tunnel junction. These states shorten the distance charge carriers must traverse across the tunnel junction.Type: GrantFiled: February 22, 2006Date of Patent: February 28, 2012Assignee: Cree, Inc.Inventors: James P. Ibbetson, Bernd P. Keller, Umesh K. Mishra
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Patent number: 8076835Abstract: A multi-chip lighting emitting device (LED) lamp for providing white light includes a submount including first and second die mounting regions thereon. A first LED chip is mounted on the first die mounting region, and a second LED chip is mounted on the second die mounting region. The LED lamp is configured to emit light having a spectral distribution including at least four different color peaks to provide the white light. For example, a first conversion material may at least partially cover the first LED chip, and may be configured to absorb at least some of the light of the first color and re-emit light of a third color. In addition, a second conversion material may at least partially cover the first and/or second LED chips, and may be configured to absorb at least some of the light of the first and/or second colors and re-emit light of a fourth color. Related light fixtures and methods are also discussed.Type: GrantFiled: May 2, 2007Date of Patent: December 13, 2011Assignee: Cree, Inc.Inventors: Nicholas W. Medendorp, Jr., Mark McClear, Bernd P. Keller, George R. Brandes, Ronan P. LeToquin
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Publication number: 20110222277Abstract: Solid state lighting devices include least one solid state emitter and multiple lumiphors, arranged to output aggregated emissions comprising at least one short wavelength blue peak, at least one long wavelength blue (LWB) peak, at least one yellow and/or green peak, and at least one red and/or orange peak. Presence of long wavelength blue enhances color rendering. At least one solid state emitter may include a short wavelength blue LED, LWB LED, and/or UV LED. Multiple emitters may be provided. Resulting devices may provide CRI greater than 85, efficiency of greater than 50 lm/watt, and color stability in a range of ?u?v??0.008 over a temperature change of 75° C.Type: ApplicationFiled: February 18, 2011Publication date: September 15, 2011Applicant: CREE, INC.Inventors: Gerald H. Negley, Antony Paul van de Ven, Bernd P. Keller, Ronan P. LeToquin, Peter Scott Andrews
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Publication number: 20110221330Abstract: Solid state lighting devcies include least one solid state emitter and multiple lumiphors, arranged to output aggregated emissions comprising at least one short wavelength blue peak, at least one long wavelength blue (LWB) peak, at least one yellow and/or green peak, and at least one red and/or orange peak. Presence of long wavelength blue enhances color rendering. At least one solid state emitter may include a short wavelength blue LED, LWB LED, and/or UV LED. Multiple emitters may be provided. Resulting devices may provide CRI greater than 85, efficiency of greater than 50 lm/watt, and color stability in a range of ?u?v??0.008 over a temperature change of 75° C.Type: ApplicationFiled: March 9, 2010Publication date: September 15, 2011Applicant: CREE, INC.Inventors: Gerald H. Negley, Antony Paul Van De Ven, Bernd P. Keller, Ronan P. LeToquin, Peter Scott Andrews
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Publication number: 20110050125Abstract: A multi-chip lighting emitting device (LED) lamp for providing white light includes a submount including first and second die mounting regions thereon. A first LED chip is mounted on the first die mounting region, and a second LED chip is mounted on the second die mounting region. The LED lamp is configured to emit light having a spectral distribution including at least four different color peaks to provide the white light. For example, a first conversion material may at least partially cover the first LED chip, and may be configured to absorb at least some of the light of the first color and re-emit light of a third color. In addition, a second conversion material may at least partially cover the first and/or second LED chips, and may be configured to absorb at least some of the light of the first and/or second colors and re-emit light of a fourth color. Related light fixtures and methods are also disclosed.Type: ApplicationFiled: November 5, 2010Publication date: March 3, 2011Applicant: CREE, INC.Inventors: Nicholas W. Medendorp, JR., Mark McClear, Bernd P. Keller, George R. Brandes, Ronan P. LeToquin
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Publication number: 20110037080Abstract: Methods of forming a light emitting device package assembly include defining a chromaticity region in a two dimensional chromaticity space within a 10-step MacAdam ellipse of a target chromaticity point, and subdividing the defined chromaticity region into at least three chromaticity subregions, providing a plurality of light emitting devices that emit light having a chromaticity that falls within the defined chromaticity region, selecting at least three of the plurality of light emitting devices, wherein each of the three light emitting devices emits light from a different one of the chromaticity subregions. The at least three light emitting devices are selected from chromaticity subregions that are complementary relative to the target chromaticity point to at least one other chromaticity subregion from which a light emitting device is selected.Type: ApplicationFiled: July 19, 2010Publication date: February 17, 2011Inventors: David Todd Emerson, Bernd P. Keller, Mark McOlear, Peter S. Andrews
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Publication number: 20100224860Abstract: An LED made from a wide band gap semiconductor material and having a low resistance p-type confinement layer with a tunnel junction in a wide band gap semiconductor device is disclosed. A dissimilar material is placed at the tunnel junction where the material generates a natural dipole. This natural dipole is used to form a junction having a tunnel width that is smaller than such a width would be without the dissimilar material. A low resistance p-type confinement layer having a tunnel junction in a wide band gap semiconductor device may be fabricated by generating a polarization charge in the junction of the confinement layer, and forming a tunnel width in the junction that is smaller than the width would be without the polarization charge. Tunneling through the tunnel junction in the confinement layer may be enhanced by the addition of impurities within the junction. These impurities may form band gap states in the junction.Type: ApplicationFiled: May 18, 2010Publication date: September 9, 2010Inventors: James P. IBBETSON, Bernd P. Keller, Umesh K. Mishra
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Patent number: 7737451Abstract: An LED made from a wide band gap semiconductor material and having a low resistance p-type confinement layer with a tunnel junction in a wide band gap semiconductor device is disclosed. A dissimilar material is placed at the tunnel junction where the material generates a natural dipole. This natural dipole is used to form a junction having a tunnel width that is smaller than such a width would be without the dissimilar material. A low resistance p-type confinement layer having a tunnel junction in a wide band gap semiconductor device may be fabricated by generating a polarization charge in the junction of the confinement layer, and forming a tunnel width in the junction that is smaller than the width would be without the polarization charge. Tunneling through the tunnel junction in the confinement layer may be enhanced by the addition of impurities within the junction. These impurities may form band gap states in the junction.Type: GrantFiled: February 23, 2006Date of Patent: June 15, 2010Assignee: Cree, Inc.Inventors: James P. Ibbetson, Bernd P. Keller, Umesh K. Mishra
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Publication number: 20090261358Abstract: A method for fabricating light emitting diode (LED) chips comprising providing a plurality of LEDs, typically on a wafer, and coating the LEDs with a conversion material so that at least some light from the LEDs passes through the conversion material and is converted. The light emission from the LED chips comprises light from the conversion material, typically in combination with LED light. The emission characteristics of at least some of the LED chips is measured and at least some of the conversion material over the LEDs is removed to alter the emission characteristics of the LED chips. The invention is particularly applicable to fabricating LED chips on a wafer where the LED chips have light emission characteristics that are within a range of target emission characteristics. This target range can fall within an emission region on a CIE curve to reduce the need for binning of the LEDs from the wafer.Type: ApplicationFiled: March 30, 2009Publication date: October 22, 2009Inventors: ASHAY CHITNIS, JOHN EDMOND, JEFFREY CARL BRITT, BERND P. KELLER, DAVID TODD EMERSON, MICHAEL JOHN BERGMANN, JASPER S. CABALU
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Patent number: D593968Type: GrantFiled: November 25, 2008Date of Patent: June 9, 2009Assignee: Cree, Inc.Inventors: John Edmond, James Ibbetson, Michael John Bergmann, Amber Christine Salter, David Todd Emerson, Ashay Chitnis, Bernd P. Keller, Kevin Haberern
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Patent number: D602450Type: GrantFiled: November 13, 2008Date of Patent: October 20, 2009Assignee: Cree, Inc.Inventors: John Edmond, James Ibbetson, Michael John Bergmann, Amber Christine Salter, David Todd Emerson, Ashay Chitnis, Bernd P. Keller, Kevin Haberern