Abstract:
A substrate for an LED emitter includes a body with a recess region formed therein. Bonding pads are disposed within the recess region, including LED bonding pads for LEDs and supporting chip bonding pads for one or more semiconductor chips that provide supporting circuitry (e.g., driver and/or controller circuitry) to support operation of the LEDs. External electrical contacts can be disposed outside the recess region. Electrical paths, disposed at least partially within the body of the substrate, connect the external electrical contacts to a first subset of the supporting chip bonding pads and connect a second subset of the supporting chip bonding pads to the plurality of LED bonding pads such that one or more supporting chips connected to the controller pads can be operated to deliver different operating currents to different ones of the LEDs.
Abstract:
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.
Abstract:
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.
Abstract:
A first sequence of pulses having a high frequency can be modulated using a second sequence of pulses having a lower frequency. The pulse width of the second sequence of pulses can be perturbed from a nominal pulse width on a per-pulse basis, within a perturbation range corresponding to the pulse period of the first sequence of pulses. In one application, the resulting output can be used to drive LEDs. In some instances, two or more channels of LEDs of different colors can be supported, with the pulse width of the first pulse sequence being selected per-channel based on a desired light color and the nominal pulse width of the second pulse sequence being selected for all channels based on a desired brightness.
Abstract:
A flexible sheet of light-emitting diode (LED) light emitters includes a support substrate having a thermally conductive material. The flexible sheet of LED light emitters also has an LED emitter sheet overlying the support substrate, and the LED emitter sheet including a plurality of LED light emitters. The flexible sheet of LED light emitters also has a flexible circuit sheet overlying the LED emitter sheet, and a phosphor sheet overlying the flexible circuit sheet. The phosphor sheet includes a wave-length converting material. The flexible sheet of LED light emitters also has a lens sheet overlying the phosphor sheet. The lens sheet includes a plurality of lenses.
Abstract:
According to some embodiments of the invention, a light-emitting device package includes a body including top and bottom surfaces and a cavity in the body, the cavity extending from the top surface towards the bottom surface and having a floor. The light-emitting device package also includes a plurality of LED (light-emitting-diode) dies disposed on the floor of the cavity. A socket is formed over the plurality of LED dies. The socket includes a top surface, a socket sidewall, and a bottom surface, the socket sidewall disposed between the top surface and the bottom surface of the socket. A lens is disposed over the over the socket. The lens includes two or more optical materials with different indices of refraction. The lens includes a cap and a plug. The cap has an upper surface and a lower surface, and the plug has a lower surface and a plug sidewall between the lower surface of the plug and the lower surface of the cap.
Abstract:
An emitter for an LED-based lighting device has multiple groups of LEDs that are independently addressable, allowing the emitter to be tuned to a desired color bin (e.g., a specific white color) by adjusting the relative current supplied to different groups. The LED dies for the groups and a phosphor chip for each LED die are individually selected such that each LED-die/phosphor-chip combination produces light in a desired source region associated with the group to which the LED belongs. Robotic pick-and-place systems can be used to automate assembly of the emitters by selecting LED dies from a bin based on based on spectral characteristics and phosphor chips from a number of distinct phosphor chip types.
Abstract:
A lamp includes a single emitter structure having a substrate with 25 or more light emitting diodes (LEDs) arranged thereon and a power rating of 80 Watts or more, a total internal reflection (TIR) lens with a plurality of refractive surface regions disposed on the step-shaped upper surface of the optical body, and a holder having a plurality of tabs disposed along an inside rim of the holder and configured for radial compression fit with a flange of the lens, and three or more support members configured for centering the optical body member with respect to the single emitter structure.
Abstract:
A method for forming a flexible sheet of LED light emitters includes forming a micro lens sheet having a plurality of micro lenses, forming a phosphor sheet including a wave-length converting material, forming a flexible circuit sheet, forming a ceramic substrate sheet including a plurality of LED light emitters, and forming a support substrate including a thermally conductive material. The method also includes attaching the above sheets to form a stack including, from top to bottom, the micro lens sheet, the phosphor sheet, the flexible circuit sheet, the ceramic substrate sheet, and the support substrate.
Abstract:
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 X0 and Y0 for 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 X0 and Y0 as a candidate for forming a light emitter of M LEDs.