Patents Assigned to Lumileds Lighting U.S., LLC
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Publication number: 20040227869Abstract: A backlight illumination system for illuminating a large area with light of a uniform color has a set of a pre-determined number of light emitters arranged along a straight line. The set is divided in a plurality of subsets, each subset including at least two light emitters. Each subset comprises light emitters with substantially the same light-emission color point, the respective subsets having color points different from each other. As a first step, the light emitters of the subset with a smallest number of light emitters are assigned to respective substantially equidistant positions. The light emitters of the set are assigned to the respective positions by iteratively starting with the subset with the smallest number of light emitters, assigning the light emitters of the subset to substantially equidistant positions which are not yet occupied. The backlight illumination system according to the invention has a uniform light and color distribution.Type: ApplicationFiled: March 25, 2004Publication date: November 18, 2004Applicant: Lumileds Lighting U.S., LLCInventors: Youri Martynov, Johannes Willem Herman Sillevis Smitt, Gibbo Johannes Abrahamse, Wilhelmus Adrianus Gerardus Timmers
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Patent number: 6800500Abstract: A III-nitride light-emitting structure including a p-type layer, an n-type layer, and a light emitting layer is grown on a growth substrate. The III-nitride light-emitting structure is wafer bonded to a host substrate, then the growth substrate is removed. In some embodiments, a first electrical contact and first bonding layer are formed on the III-nitride light-emitting structure. A second bonding layer is formed on the host substrate. In such embodiments, wafer bonding the III-nitride light emitting structure to the host substrate comprises bonding the first bonding layer to the second bonding layer. After the growth substrate is removed, a second electrical contact may be formed on a side of the III-nitride light-emitting device exposed by removal of the growth substrate.Type: GrantFiled: July 29, 2003Date of Patent: October 5, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Carrie Carter Coman, Fred A. Kish, Jr., Michael R Krames, Paul S Martin
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Patent number: 6796680Abstract: A strip lighting device includes an elongate housing, a plurality of light sources arranged at intervals within the housing, and a fastener for fastening the elongate housing to a surface. The elongate housing overlies the plurality of light sources and diffuses, disperses or scatters light from the light sources such that individuals of the plurality of light sources are substantially not distinguishable when the housing is viewed from the outside.Type: GrantFiled: January 28, 2000Date of Patent: September 28, 2004Assignee: Lumileds Lighting U.S., LLCInventors: David Field Showers, James Berry Quantrell, Kenneth Robert Goddard, Malcolm Wesley Oldis
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Patent number: 6794731Abstract: A method for improving the operating stability of compound semiconductor minority carrier devices and the devices created using this method are described. The method describes intentional introduction of impurities into the layers adjacent to the active region, which impurities act as a barrier to the degradation process, particularly undesired defect formation and propagation. A preferred embodiment of the present invention uses O doping of III-V optoelectronic devices during an epitaxial growth process to improve the operating reliability of the devices.Type: GrantFiled: October 9, 1998Date of Patent: September 21, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Stephen A. Stockman, Daniel A. Steigerwald, Changhua Chen
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Patent number: 6784463Abstract: A light-emitting semiconductor device includes a stack of layers including an active region. The active region includes a semiconductor selected from the group consisting of III-Phosphides, III-Arsenides, and alloys thereof. A superstrate substantially transparent to light emitted by the active region is disposed on a first side of the stack. First and second electrical contacts electrically coupled to apply a voltage across the active region are disposed on a second side of the stack opposite to the first side. In some embodiments, a larger fraction of light emitted by the active region exits the stack through the first side than through the second side. Consequently, the light-emitting semiconductor device may be advantageously mounted as a flip chip to a submount, for example.Type: GrantFiled: March 11, 2002Date of Patent: August 31, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Michael D. Camras, Daniel A. Steigerwald, Frank M. Steranka, Michael J. Ludowise, Paul S. Martin, Michael R. Krames, Fred A. Kish, Stephen A. Stockman
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Publication number: 20040145320Abstract: In a lighting arrangement comprising a LED array and a DC-DC-converter for supplying the LED array, the DC-DC-converter is an up-converter and the LED array is coupled between an input terminal and an output terminal. The up-converter generates a very low voltage over the LED array without making use of a transformer.Type: ApplicationFiled: December 2, 2003Publication date: July 29, 2004Applicant: Lumileds Lighting U.S., LLCInventors: Engbert Bernard Gerard Nijhof, Marcel Johannes Maria Bucks, Johannes Matheus Theodorus Lambertus Claessens, Jozef Petrus Emanuel De Krijger
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Patent number: 6768525Abstract: A color, transmissive LCD is described herein which uses red, green, and blue LEDs as the light source. The R, G, and B LEDs are coupled to separate light guides, one light guide for each color. These light guides may take the form of three overlying plastic or glass sheets. In another embodiment, thin fiber optic cables arranged parallel to each other on a supporting surface are used as the light guides, and each fiber optic cable is optically coupled to only one R, G, or B LED in a repeating pattern. The light guides contain deformities to emit light coinciding with the positions of the red, green, and blue pixels. The R, G, and B LEDs are constantly on, and there is no color filtering.Type: GrantFiled: December 1, 2000Date of Patent: July 27, 2004Assignee: Lumileds Lighting U.S. LLCInventors: Steven Paolini, Gerard Harbers, Wayne L. Snyder
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Publication number: 20040130518Abstract: In a circuit arrangement for driving a LED array comprising red, green and blue LEDs, a control loop is added for limiting the duty cycles of the control signals for driving the red, green and blue LEDs. In case one of the duty cycles reaches the limit value, the reference signals for the red, green and blue light are decreased with the same relative amount. The color point of the light is thereby maintained, even when the efficiency of part of the LEDs decreases.Type: ApplicationFiled: October 9, 2003Publication date: July 8, 2004Applicant: Lumileds Lighting U.S., LLCInventors: Jozef Petrus Emanuel De Krijger, Armand Boudewijn Perduijn, Engbert Bernard Gerard Nijhof, Marcel Johannes Maria Bucks
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Patent number: 6756186Abstract: A method of forming a photoresist mask on a light emitting device is disclosed. A portion of the light emitting device is coated with photoresist. A portion of the photoresist is exposed by light impinging on the interface of the light emitting device and the photoresist from inside the light emitting device. The photoresist is developed, removing either the exposed photoresist or the unexposed photoresist. In one embodiment, the photoresist mask may be used to form a phosphor coating. After the photoresist is developed to remove the exposed photoresist, a phosphor layer is deposited overlying the light emitting device. The unexposed portion of photoresist is stripped. In some embodiments, the light exposing the photoresist is produced by electrically biasing the light emitting device, or by shining light into the light emitting device through an aperture or by a focussed laser.Type: GrantFiled: March 22, 2002Date of Patent: June 29, 2004Assignee: Lumileds Lighting U.S., LLCInventors: William D. Collins, III, Wayne L. Snyder, Daniel A. Steigerwald
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Patent number: 6744077Abstract: A light emitting device includes a semiconductor light emitting device chip having a top surface and a side surface, a wavelength-converting material overlying at least a portion of the top surface and the side surface of the chip, and a filter material overlying the wavelength-converting material. The chip is capable of emitting light of a first wavelength, the wavelength-converting material is capable of absorbing light of the first wavelength and emitting light of a second wavelength, and the filter material is capable of absorbing light of the first wavelength. In other embodiments, a light emitting device includes a filter material capable of reflecting light of a first wavelength and transmitting light of a second wavelength.Type: GrantFiled: September 27, 2002Date of Patent: June 1, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Troy A. Trottier, Gerd O. Mueller, Regina B. Mueller-Mach, Michael R. Krames
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Publication number: 20040095185Abstract: In an up-converter feed forward control of the output current is effected by rendering the conduction time of the switching element proportional to Vout/Vin2. This control is fast and avoids interference and loss of efficiency.Type: ApplicationFiled: July 7, 2003Publication date: May 20, 2004Applicant: Lumileds Lighting U.S., LLCInventors: Marcel Johannes Maria Bucks, Johannes Mathcus Theodorus Lambertus Claessens, Jozef Petrus Emanuel De Krijger, Engbert Bernard Gerard Nijhof
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Patent number: 6730940Abstract: The amount of usefully captured light in an optical system may be increased by concentrating light in a region where it can be collected by the optical system. A light emitting device may include a substrate and a plurality of semiconductor layers. In some embodiments, a reflective material overlies a portion of the substrate and has an opening through which light exits the device. In some embodiments, reflective material overlies a portion of a surface of the semiconductor layers and has an opening through which light exits the device. In some embodiments, a light emitting device includes a transparent member with a first surface and an exit surface. At least one light emitting diode is disposed on the first surface. The transparent member is shaped such that light emitted from the light emitting diode is directed toward the exit surface.Type: GrantFiled: October 29, 2002Date of Patent: May 4, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Frank M. Steranka, Daniel A. Steigerwald, Matthijs H. Keuper
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Publication number: 20040079942Abstract: The amount of usefully captured light in an optical system may be increased by concentrating light in a region where it can be collected by the optical system. A light emitting device may include a substrate and a plurality of semiconductor layers. In some embodiments, a reflective material overlies a portion of the substrate and has an opening through which light exits the device. In some embodiments, reflective material overlies a portion of a surface of the semiconductor layers and has an opening through which light exits the device. In some embodiments, a light emitting device includes a transparent member with a first surface and an exit surface. At least one light emitting diode is disposed on the first surface. The transparent member is shaped such that light emitted from the light emitting diode is directed toward the exit surface.Type: ApplicationFiled: October 29, 2002Publication date: April 29, 2004Applicant: Lumileds Lighting, U.S., LLCInventors: Frank M. Steranka, Daniel A. Steigerwald
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Patent number: 6717353Abstract: A device includes a semiconductor light emitting device and a wavelength-converting material comprising Sr—SiON:Eu2+. The Sr—SiON:Eu2+ wavelength-converting material absorbs light emitted by the light emitting device and emits light of a longer wavelength. The Sr—SiON:Eu2+ wavelength-converting material may be combined with other wavelength-converting materials to make white light. In some embodiments, the Sr—SiON:Eu2+ wavelength-converting layer is combined with a red-emitting wavelength-converting layer and a blue light emitting device to generate emission in colors, which are not achievable by only mixing primary and secondary wavelengths. In some embodiments, the Sr—SiON:Eu2+ wavelength-converting layer is combined with a red-emitting wavelength-converting layer, a blue-emitting wavelength-converting layer, and a UV light emitting device.Type: GrantFiled: October 14, 2002Date of Patent: April 6, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Gerd O. Mueller, Regina B. Mueller-Mach, Peter J. Schmidt, Thomas Jüstel, Gerry Sorce
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Publication number: 20040061810Abstract: A backlight for an LCD uses as a light source at least one red light source, at lest one green light source, at least one blue light source, wherein one of the sources comprises a light emitting diode capable of emitting light at a first wavelength and a wavelength-converting material capable of absorbing light of the first wavelength and emitting light of a second wavelenght. In some embodiments, the wavelength-converting material is a strontium thiogallate phosphor or a nitridosilicate phosphor. In some embodiments, the first wavelength is about the same as light emitted by the blue light source, or is barely visible to the human eye.Type: ApplicationFiled: September 27, 2002Publication date: April 1, 2004Applicant: Lumileds Lighting, U.S., LLCInventors: Christopher H. Lowery, Wim Timmers, J. Willem H. Sillevis Smitt
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Publication number: 20040061124Abstract: A light emitting device includes a semiconductor light emitting device chip having a top surface and a side surface, a wavelength-converting material overlying at least a portion of the top surface and the side surface of the chip, and a filter material overlying the wavelength-converting material. The chip is capable of emitting light of a first wavelength, the wavelength-converting material is capable of absorbing light of the first wavelength and emitting light of a second wavelength, and the filter material is capable of absorbing light of the first wavelength. In other embodiments, a light emitting device includes a filter material capable of reflecting light of a first wavelength and transmitting light of a second wavelength.Type: ApplicationFiled: September 27, 2002Publication date: April 1, 2004Applicant: Lumileds Lighting U.S., LLCInventors: Troy A. Trottier, Gerd O. Mueller, Regina B. Mueller-Mach, Michael R. Krames
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Patent number: 6696703Abstract: The present invention provides a phosphor-converted LED device comprising one or more phosphor thin films that convert primary light emitted by the LED into one or more other wavelengths of light to produce light of a particular color. Each phosphor thin film comprises dopant ions that are statistically spatially distributed in such a manner that the phosphor conversion of the primary light is predictable and controlled by the concentration of the dopants and by the thickness of the thin film. Therefore, variations in the color of the light produced by phosphor-converted LED devices can be eliminated, thereby enabling uniformity in the quality of the colored light produced to be ensured. In accordance with one embodiment of the present invention, a single phosphor thin film is comprised by the LED device. The thin film converts a portion of the primary emission into yellow light while allowing a portion of the primary blue light to pass through the thin film.Type: GrantFiled: September 27, 1999Date of Patent: February 24, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Regina B. Mueller-Mach, Gerd O. Mueller
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Patent number: 6686691Abstract: The present invention relates to a tri-color lamp for generating white light. In particular, the invention relates to a phosphor mixture comprising two phosphors having host sulfide materials that can absorb radiation emitted by a light emitting diode, particularly a blue LED. This arrangement provides a mixing of three light sources—light emitted from the two phosphors and unabsorbed light emitted from the LED. The phosphors can contain the same dopant, such as a rare earth ion, to allow matching of the phosphors in relation to the LED emitted radiation. Power fractions of each of the light sources can be varied to achieve good color rendering. The present invention also relates to an alternative to a green LED comprising a single green phosphor that absorbs radiation from a blue LED. A resulting device provides green light of high absorption efficiency and high luminous equivalent values.Type: GrantFiled: September 27, 1999Date of Patent: February 3, 2004Assignee: Lumileds Lighting, U.S., LLCInventors: Gerd O Mueller, Regina B Mueller-Mach, Christopher H Lowery
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Patent number: 6686581Abstract: A LED is covered with an electroconductive layer, and a luminescent layer is deposited on the electroconductive layer by electrophoresis. The conductivity of the electroconductive layer is chosen to be such that the layer can be used as one of the electrodes during the electrophoresis, while the LED is not short-circuited by the electroconductive layer during normal operation.Type: GrantFiled: June 26, 2001Date of Patent: February 3, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Godefridus Johannes Verhoeckx, Nicolaas Joseph Martin Van Leth, Cornelis Gerardus Visser
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Patent number: 6682207Abstract: A light emitting device comprises a light emitting diode that emits primary light and a SrGa2S4:Eu2+ phosphor material capable of absorbing at least a portion of the primary light and emitting secondary light. The secondary light includes a wavelength longer than a wavelength of the primary light.Type: GrantFiled: June 22, 2001Date of Patent: January 27, 2004Assignee: Lumileds Lighting U.S., LLCInventors: Andreas G. Weber, Gregory M. Cutler, William R. Trutna, Jr., Gerd O. Muller, Regina B. Muller-Mach