Ledengin, Inc.

Agilent Technologies, Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Emcore Corporation

K2 Optronics, Inc.

Zequn Mei

Xiantao Yan

Kachun Lee

Wu Jiang

John Cameron Major

Frans Kusnadi

Richard D Bjorn

Debo A Adebiyi

Truc Phuong Thi Vu

Xianto Yan

Truc Phoung Thi Vu

Danny Gonzales

Ali Eslambolchi

William E Armstrong

An LED-based lamp can be made to have a form factor compatible with fixtures designed for MR16 lamps. Such a lamp can have a housing that provides an external electrical connection. Inside the housing is disposed a single emitter structure having a substrate with multiple light-emitting diodes (LEDs) arranged thereon. Different LEDs produce light of different colors (or color temperatures). For example, at least one LED can produce a warm white light, while at least one other LED produces a cool white light and at least one other LED produces a red light. A total-internal-reflection (TIR) lens is positioned to collect light emitted from the single emitter structure and adapted to mix the light from the LEDs to produce a uniform white light. A diffusive coating is applied to a front face of the TIR lens for further color mixing.

LED-based MR16 replacement lamp

LED-based light source modules can incorporate color tunability and brightness control, allowing a user to select a desired color temperature and/or brightness and to change either or both dynamically. An emitter can include multiple independently addressable groups of LEDs, each emitting light of a different color. By controlling the relative operating current provided to each group, a desired color temperature can be achieved, and by controlling the absolute operating currents, the brightness of the output light can be controlled. Pulse width modulation (PWM) can be used to control the relative and absolute operating currents. Smooth, gradual transitions between brightness and/or color temperature settings in response to changes can be provided.

Color tunable light source module with brightness and dimming control

Color tunable light source module with brightness control

A method for fabricating light-emitting devices includes obtaining a plurality of light-emitting diode (LED) chips fabricated to emit blue light and preparing a phosphor-containing material comprising a matrix material having dispersed therein a mixture of a red phosphor and a green phosphor in a fixed ratio to each other. The method also includes disposing different thicknesses of the phosphor-containing material on different ones of the LED chips. The fixed ratio is chosen such that LED chips having different thicknesses of the phosphor-containing material emit light characterized by different points along the Planckian locus in a CIE chromaticity diagram.

Phosphors for warm white emitters

An LED light emitter includes a single emitter structure having a substrate with a plurality of light emitting diodes (LEDs) arranged thereon, wherein the plurality of LEDs includes at least one first LED die that produces a first color light, and at least one second LED die that produces a second color light. The LED light emitter also includes a total internal reflection (TIR) lens positioned to collect light emitted from the single emitter structure and adapted to mix the light from the plurality of LEDs to produce a uniform light. The plurality of LEDs are selected such that the light output by the LED light emitter has a desired color temperature when an equal current is supplied to all of the plurality of LEDs.

System and methods for warm white LED light source

A method is provided for forming multiple-LED (light-emitting-diode) light emitters from a plurality of LEDs, wherein the number of LEDs in each emitter is an integer M. The method includes providing a plurality of LEDs, each of the LEDs characterized by a first parameter and a second parameter, which are related to color coordinates CIEx and CIEy in a chromaticity diagram. The method also includes determining first and second parameter Xand Yfor a target color. The method further includes, for all possible combinations of M LEDs out of the plurality of LEDs, determining a first group parameter and a second group parameter based on the first and second parameters for all of the M LEDs, and selecting a group of M LEDs whose first group parameter and second group parameter are closest to Xand Yas a candidate for forming a light emitter of M LEDs.

Manufacturing method for LED emitter with high color consistency

A method for depositing a layer of phosphor-containing material on a plurality of LED dies includes disposing a template with a plurality of openings on an adhesive tape and disposing each of a plurality of LED dies in one of the plurality of openings of the template. The method also includes forming a patterned dry film photoresist layer over the template and the plurality of LED dies. The photoresist layer has a plurality of openings configured to expose a top surface and side surfaces of each of the LED dies. Next, a phosphor-containing material is disposed on the exposed top surface of each the LED dies. The method further includes removing the photoresist layer and the template.

Phosphor cap for LED die top and lateral surfaces

The color of an LED-based lamp can be tuned to a desired color or color temperature. The lamp can include two or more independently addressable groups of LEDs associated with different colors or color temperatures and a total-internal-reflection (TIR) color-mixing lens to produce light of a uniform color by mixing the light from the different groups of LEDs. The color of the output light is tuned by controllably dividing an input current among the groups of LEDs. Tuning can be performed once, e.g., during manufacture, and the lamp does not require active feedback components for maintaining color temperature.

Tuning of emitter with multiple LEDs to a single color bin

A method for depositing a layer of phosphor-containing material on a plurality of LED dies includes disposing a template with a plurality of openings on an adhesive tape and disposing each of a plurality of LED dies in one of the plurality of openings of the template. The method also includes disposing a stencil over the template and the plurality of LED dies. The stencil has a plurality of openings configured to expose a top surface of each of the LED dies. Next, a phosphor-containing material is disposed on the exposed top surface of each the LED dies. The method further includes removing the stencil and the template.

Deposition of phosphor on die top by stencil printing

A method for depositing a layer of phosphor-containing material on a plurality of LED (light-emitting diode) dies on a wafer includes disposing a layer of dry photoresist film over a plurality of LED dies on a wafer, disposing a mask layer over the dry photoresist film, and patterning the dry photoresist film to form a plurality of openings in the dry photoresist film to expose a top surface of each of the LED dies. The method also includes depositing a phosphor-containing material on the exposed top surface of each the LED dies using a screen printing process, and removing the patterned dry photoresist film.

Printing phosphor on LED wafer using dry film lithography

A metal plate on a multi-die LED emitter substrate or a metal plate on a metal-core printed circuit board (MCPCB) that attaches to the emitter substrate (or both plates) can be fabricated with a number of generally radial grooves, at least some of which extend to the peripheral edge of the plate. These grooves can provide channels that allow air to escape during solder-bonding processes, reducing the size and/or total area of solder voids and thereby improving thermal transfer between the emitter and the MCPCB.

Grooved plate for improved solder bonding

A total-internal-reflection (TIR) lens for color mixing includes a body member having an outer surface and an interior open channel extending longitudinally through the body member. The body member and the interior open channel are substantially symmetric with respect to an optical axis, and the outer surface is shaped to provide total internal reflection. The body member has a first end surface region at a first end of the open channel for accommodating a light source and a second end surface region opposite the first end region. The second end surface region includes a plurality of refractive surface regions positioned around the second end region of the open channel. The lens is configured to provide projected light substantially centered with respect to the optical axis when the light source is positioned off the optical axis. In a specific embodiment, a lighting apparatus for providing centered white light includes such a lens and a plurality of light sources.

Total internal reflection lens for color mixing

A method for depositing a layer of phosphor-containing material on a plurality of LED dies includes disposing a template with a plurality of openings on an adhesive tape and disposing each of a plurality of LED dies in one of the plurality of openings of the template. The method also includes forming a patterned dry film photoresist layer over the template and the plurality of LED dies. The photoresist layer has a plurality of openings configured to expose a top surface of each of the LED dies. Next, a phosphor-containing material is disposed on the exposed top surface of each the LED dies. The method further includes removing the photoresist layer and the template.

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