Abstract:
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.
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 a ceramic substrate sheet overlying support substrate, and the ceramic substrate sheet including a plurality of LED light emitters. The flexible sheet of LED light emitters also has a flexible circuit sheet overlying the ceramic substrate 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:
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.
Abstract:
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.
Abstract:
Methods of fabricating a light-emitting device are provided. A light-emitting device can be formed from bonding a lens including a plug and a cap to an LED package including a socket configured to receive the plug. The lens can be fabricated using an injection mold formed from a well secured to the LED package and injecting a material into the injection mold to cure into a shape of the lens. The lens can also be fabricated using a blank about the shape of the lens and machining the blank to produce the plug and the cap of the lens. The lens can be bonded to the LED package using a convex bead of adhesive deposited on the surface of the LED package and spreading the adhesive between the lens and the LED package.
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:
Substrates and packages for LED-based light devices can significantly improve thermal performance and provide separate electrical and thermal paths through the substrate. One substrate includes multiple electrically insulating base layers. On a top one of these layers are disposed top-side electrical contacts, including light device pads to accommodate a plurality of light devices. External electrical contacts are disposed on an exterior surface of the substrate. Electrical paths connect the top-side electrical contacts to the external electrical contacts. At least portions of some of the electrical paths are disposed between the electrically insulating base layers. The electrical paths can be arranged such that different subsets of the light device pads are addressable independently of each other. A heat dissipation plate can be formed on the bottom surface of a bottom one of the base layers.
Abstract:
Substrates and packages for LED-based light devices can significantly improve thermal performance and provide separate electrical and thermal paths through the substrate. One substrate includes multiple electrically insulating base layers. On a top one of these layers are disposed top-side electrical contacts, including light device pads to accommodate a plurality of light devices. External electrical contacts are disposed on an exterior surface of the substrate. Electrical paths connect the top-side electrical contacts to the external electrical contacts. At least portions of some of the electrical paths are disposed between the electrically insulating base layers. The electrical paths can be arranged such that different subsets of the light device pads are addressable independently of each other. A heat dissipation plate can be formed on the bottom surface of a bottom one of the base layers.
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.