Koninklijke Philips Corporation N.V.

Philips Electronics North America Corporation

Other

Koninklijke Phillips Electronics N.v.

Lumileds Lighting B.v.

Thomas M Marshall

Michael D Pashley

Stephen A Herman

Frank J P Schuurmans

Gerard Harbers

Kevin Haberern

Gert W Bruning

Jeffrey Arthur Shimizu

Matthijs H Keuper

John Petruzello

Ans Saalberg

Larry McColloch

According to this invention, a side-emitting illumination device for uniformly distributing light is composed of an LED light source, a light-transmitting rod which permits total internal reflection, and outcoupling material affixed to an outer surface of the rod. Light enters the rod at one end and travels along the rod by total internal reflection. Light that hits the outcoupling material is angularly distributed based on the width of the outcoupling material.

Side-emitting rod for use with an LED-based light engine

White light emitting LED luminaire incorporates an array of red, green and blue emitting LEDs and a feedback arrangement to maintain a desired color balance. The feedback arrangement includes photodiodes positioned and enabled to separately measure the light output of each RGB color component. In one embodiment, a single photodiode or array of photodiodes is positioned to intercept reflected light from a partially reflecting element placed in the path of the combined output of the LED array. Individual colors are measured sequentially by pulsing the LEDs and photodiodes or by the use of color filters. In an alternate embodiment, each LED has an associated photodiode, either incorporated into the LED package or in a separate package.

LED luminaire with light sensor configurations for optical feedback

A storage compartment is equipped with a light emitting diode (LED) light source for illuminating contents inside the compartment. The LED light source includes a LED light engine outside the compartment and a light guide inside the compartment. The light guide is optically coupled to be LED light engine to bring light from the LED light engine into the compartment for providing illumination inside the compartment. The LED light engine may include red, green, and blue LEDs that contribute to the illumination inside the compartment. Respective outputs of the red, green, and blue LEDs may be separately controllable to allow a variably controlled color point of illumination inside the compartment. Total output of the LED light engine may be controllable to vary intensity of illumination inside the compartment.

LED illumination for cold storage compartments

A display device is provided which includes a first substrate having at least one transparent, first picture electrode of a first material, a second substrate having at least one second picture electrode of a second material which, jointly with the picture electrode on the first substrate and an intermediate opto-electronic material, defines a pixel, and means for supplying electric voltages to the picture electrodes, wherein at least one of the picture electrodes is coated with at least one layer of a passivating material such that any asymmetry in operation of the device is substantially reduced or eliminated.

Display device

A hybrid lighting system for producing white light including at least one light emitting diode and phosphor-light emitting diode. The hybrid lighting system exhibits improved performance over conventional LED lighting systems that use LEDs or phosphor-LEDs to produce white light. In particular, the hybrid system of the invention permits different lighting system performance parameters to be addressed and optimized as deemed important, by varying the color and number of the LEDs and/or the phosphor of the phosphor LED.

LED/phosphor-LED hybrid lighting systems

A light source includes an array of LED components in each of a plurality of colors such as red, green, and blue in the entrance aperture of a tubular reflector which has an exit aperture, an optic axis extending between the apertures, and a reflective circumferential wall extending between the apertures to reflect and mix light from the array of LED components. At least a portion of the circumferential wall of the reflector body has a polygonal cross-section taken normal to the optic axis, and at least a portion of the cross-section taken parallel to the optic axis includes segments of a curve joined one to the next to form a plurality of facets for reflecting light from the LED components to said exit aperture. Preferably, the segments of the curve included in the cross-section of the reflector body taken parallel to the optic axis are contiguous, linear trapezoidal facets.

Faceted multi-chip package to provide a beam of uniform white light from multiple monochrome LEDs

An LED module that includes an LED (light-emitting diode) and a rotationally symmetrical, bowl-shaped collimator lens is provided. The collimator lens has an inner refractive wall, an outer reflective wall, a first surface having an entrance aperture with a recess in which the LED is situated and which collimator lens is also provided with a second surface from which light generated by the LED emerges, the normal to the surface extending substantially parallel to the axis of symmetry of the lens, and the LED module also includes one or more of the following structures: (1) a conic wall portion of the recess of the inner refractive wall at the entrance aperture that includes a curved portion, and an outer reflective wall so configured in accordance with the structure of the inner refractive wall to achieve substantial collimation of a source of light at the entrance aperture; and/or (2) a first surface of the lens that is recessed away from the LED source; and/or (3) two surfaces of said refractive wall between which the refractive function of said refractive wall is divided. The LED module offers an improvement in the performance of the Flat top Tulip Collimator disclosed and claimed in our co-pending application Ser. No. 09/415,833 in terms of reduced size, beam divergence, beam uniformity, and to some degree efficiency. Moreover, it allows a wider variety of choices in optimizing various performance characteristics, and this in turn allows more flexibility in the structure design.

LED collimation optics with improved performance and reduced size

A luminaire comprises an array of LEDs that include at least one LED in each of a plurality of colors. Supplied to the LEDs for each color is an electrical current that, during a measuring period, comprises a measuring drive pulse having at least a first boost portion and a turn-off portion. The LEDs relating to each color have a light output which has a nominal continuous value during ordinary operation and increases during the boost portion and is interrupted during the turn-off portion. The array has a combined light output when current is supplied to all of the LEDs in the array. A photodiode is arranged to measure the combined light output which selectively turning off the electrical current to the LEDs so that the photodiode measures the light output for each color separately in response to the measuring drive pulse. The average light output during the measuring period is substantially equal to the nominal continuous light output during the ordinary operation so as to avoid visible flickers.

Led luminaire with electrically adjusted color balance

A lens array for a lamp directs light to a light conduit such as an optical fiber or light pipe for guiding light to a remote location. An array of LED serve as light sources. The lens array includes an integrally formed member having a number of collimator lenses positioned in the lens array so that each lens can operate as a collimator for a corresponding LED to produce a respective collimated beam of light. The lenses have optical properties that are optimized according to where their corresponding LED are positioned in the LED array, so that the lens array is provided with lens prescriptions that produce refraction of the collimated beams of light toward an entrance aperture of the light conduit.

One-piece lens arrays for collimating and focusing light and led light generators using same

A faceted surface has first and second facets which deflect respective first and second light beams to produce first sub-beams which alternate with second sub-beams. The faceted surface may be a reflector having first facets at 120&deg; to second facets for mixing light beams which are incident at 120&deg; to each other. 100% of reflected sub-beams from each source alternate with 100% of sub-beams from the other source. The faceted surface may also be a refractor which is part of a transparent block having two parallel faceted surfaces. A first refractive surface refracts parallel light beams to produce diverging beams which are each split into spaced apart sub-beams by the second refractive surface. 50% of refracted sub-beams originating from each source alternate with 50% of refracted sub-beams of each adjacent source.

Apparatus for mixing light from different color LEDs

A linear array of LED light sources in a plurality of colors is situated along the length of a reflector which is positioned so that it receives substantially all the light within the semi-cone angles of the sources, and is shaped so that it is illuminated substantially uniformly along its width. The reflector may be configured as a smooth Lambertian surface, or may be configured as a curve approximated by a series of flat specular reflecting segments.

Low-profile luminaire having a reflector for mixing light from a multi-color linear array of LEDs

A light source includes an array of LEDs in each of a plurality colors such as red, green, and blue in the entrance aperture of a tubular reflector which preferably has convex walls facing the optic axis and flares outward toward the exit aperture, and preferably has a polygonal cross section such as a square. Mixing of colors is further promoted by utilizing a large number of small LEDs with the LEDs of each color being centered on the optic axis.

Luminaire having a reflector for mixing light from a multi-color array of leds

A device, e.g., a luminaire, that includes a plurality of LEDs connected in series, and an active shunt arrangement for sensing a failure of one or more of the LEDs and for shunting current that would have otherwise flowed through a failed LED, to thereby maintain a flow of current through remaining ones of the plurality of LEDs. In one exemplary embodiment, the active shunt arrangement includes a plurality of active shunts connected in parallel across respective ones of the LEDs, and remote sense and digital control logic for detecting an open-circuit condition of the normally closed circuit, and for sequentially activating the active shunts until the normally closed circuit has been restored to a closed-circuit condition. In another exemplary embodiment, the active shunt arrangement includes a plurality of active shunts connected in parallel across respective ones of the LEDs, a plurality of sense circuits operatively associated with respective ones of the LEDs, each of the sense circuits being configured to sense a failure condition of its associated LED, and to produce a sense output signal upon sensing a failure condition of its associated LED, and a plurality of control circuits operatively associated with respective ones of the LEDs and respective ones of the sense circuits, each of the control circuits being responsive to the sense output signal produced by its associated sense circuit to activate the active shunt connected across its associated LED. Preferably, each of the active shunts is an active switching device, such as a power MOSFET, a bipolar transistor, or a micro-relay, that has a low on-resistance.

LED array having an active shunt arrangement

Apparatus for mixing light from discrete LED light sources utilizes beam splitters which each have a semi-reflective layer which partially transmits and partially reflects light of any wavelength incident thereon. Each semi-reflective layer is situated in a transparent prismatic black between reflective surfaces on parallel outside faces of the block so that two parallel input beams are mixed and transmitted as two parallel mixed beams of like color. For a square array of light sources, a first mixing stage consists of two such prismatic blocks arranged side-by-side, and a second mixing stage consists of two such prismatic blocks arranged side-by-side and rotated 90 degrees to the first stage. The second stage is arranged to receive a square array of mixed beams and produces four identical output beams. The colors of the light sources are chosen so that all output beams are white.

Growing community of inventors

Hartsdale, NY, United States of America

Thomas M Marshall