Abstract: In one embodiment, an overhead street light (a luminaire) is formed that has an asymmetric light intensity distribution, where the peak intensity is greatest along the direction of the street, lower directly across the street, and much lower on the house side of the street. Around the edge of a circular transparent light guide are white light LEDs that inject light into the light guide. To help control the asymmetry of the light intensity distribution, sawtooth-shaped grooves are formed in the light guide surface opposite to the light-emission surface and parallel to the street. Gaussian diffusers are used to partially diffuse the light. By proper selection of the grooves, the Gaussian diffuser, and the relative amounts of light emitted by LED segments around the light guide, the desired asymmetrical light intensity distribution is achieved while a direct view of the light exit surface appears as a uniform light.

Abstract: An illumination system is disclosed that is arranged to compensate for variations in brightness between different LEDs in the system. The system may include an array of LEDs coupled to a light guide that is provided with a plurality of light extraction patterns. Each light extraction pattern may include a plurality of light extraction features. The light extraction patterns may differ from one another in the density of the features. Light extraction patterns having a greater density may be combined with LEDs in the array that are less bright, whereas light extraction patterns having a lower feature density may be combined with LEDs in the array that are brighter.

Abstract: A light engine and system using the light engine are disclosed. The light engine includes a core and independently addressable LED segments. Each LED segment has multiple LEDs. A flexible PCB contains a body to which the LED segments are attached and legs. Each leg provides electrical contact for a different LED segment. The body is attached to the core. A light guide plate (LGP) is disposed such that light from the LED segments is introduced thereto, guided, and from which the light exits to provide illumination. The LED segments emit light in all directions of a plane created by the LGP.

Abstract: A flexible printed circuit board and method of fabrication are disclosed. The flexible printed circuit board has a flexible body with multiple segments. Each segment has multiple body contacts that are electrically isolated from body contacts of each other segment. The flexible printed circuit further has multiple flexible legs in which each leg extends from a different segment and contains multiple leg contacts disposed proximate to a distal end of the leg from the body. Each leg contact is connected with a different body contact of the leg. The flexible printed circuit board is formed from a multilayer structure that includes: a dielectric layer, a metal layer adjacent to the dielectric layer, and a solder mask layer adjacent to the metal layer, the solder mask layer exposing portions of the metal layer to form the body contacts.

Abstract: A light engine and system are disclosed in which the light engine contains a core comprising an opening extending through opposing surfaces and a flexible printed circuit board (PCB). The PCB includes a flexible body disposed on an outside of the core and having independently addressable sets of illumination sources mounted thereto, and flexible legs extending from the body and through the opening. The legs are bent such that a terminal portion of each leg is substantially parallel to the opposing surfaces of the core. Independent control of the sets of illumination sources is provided via the legs. The body is separated into segments, each on a different section of the outside and containing body contacts electrically independent of the body contacts of each other segment. Each leg is associated with a different segment, and contains leg contacts on the terminal portion in electrical contact with the associated body contacts.

Abstract: A light engine is disclosed in which the light engine contains a core having an opening extending completely therethrough and independently addressable LED segments. The opening defines an inner surface of the core. Each segment has LEDs and is attached to a flexible PCB. The PCB has a flexible body attached to one of an inner or outer surface of the core and to which the segments are mounted, and flexible legs extending from the body, along the core, and traverse and adjacent to the other of the inner or outer surface. A light guide plate (LGP) receives and guides light from the segments so that the light exits to provide illumination. The segments emit light in all directions of a plane created by the LGP. A reflector opposes and covers a top surface of the LGP and the segments and reflects light from the LGP back into the LGP.

Abstract: An apparatus is disclosed comprising: a light guide having an opening formed thereon; an illumination source at least partially disposed in the opening, the illumination source including a plurality of LEDs disposed on a flexible circuit that is wrapped around a base, which may be thermally conductive, the base having a central opening, and the flexible circuit including a plurality of legs, each leg including electrical wiring for independently operating a different one of the LEDs, each leg being wrapped around a bottom edge of the base, and into the central opening, to come above the illumination source and connect to a control board that is situated above the illumination source; and a heat-dissipating element disposed over the illumination source, the heat-dissipating element being thermally coupled to the base to dissipate heat generated by the LEDs that is supplied to the heat dissipating element via the base.

Abstract: A light engine is disclosed in which the light engine contains a core comprising an opening extending completely through the core and independently addressable LED segments. The opening defines an inner surface of the core. Each segment has multiple LEDs. A PCB contains a body adjacent to one of an inner or outer surface of the core and to which the LED segments are attached and legs extending from the body and bent to be adjacent and traverse to the other of the inner or outer surface. Each leg is associated with a different LED segment. Control circuitry is connected with the legs of the flexible PCB and independently controls parameters of the LED segments to provide a preset illumination distribution and intensity based on user input.

Abstract: An apparatus is disclosed including a light guide and a plurality of light emitting diodes (LEDs). The light guide includes a rear portion including a first edge, a second edge, and a rear edge. The first edge meets the rear edge at a first obtuse angle, and the second edge meets the rear edge at a second obtuse angle. The plurality of light emitting diodes (LEDs) disposed on the first edge, the second edge, and the rear edge, and it is arranged to produce an asymmetric light distribution pattern including a rear light emission and a forward light emission having a greater peak intensity than the rear light emission.

Abstract: An illumination system is disclosed that is arranged to compensate for variations in brightness between different LEDs in the system. The system may include an array of LEDs coupled to a light guide that is provided with a plurality of light extraction patterns. Each light extraction pattern may include a plurality of light extraction features. The light extraction patterns may differ from one another in the density of the features. Light extraction patterns having a greater density may be combined with LEDs in the array that are less bright, whereas light extraction patterns having a lower feature density may be combined with LEDs in the array that are brighter.

Abstract: A light-emitting device comprising: a light source; and a light guide that is optically coupled to the light source, the light guide including a plurality of first non-fluorescent light extraction elements and a plurality of second non-fluorescent light extraction elements that are printed on the light guide, each of the first light extraction elements having a reflectance that is higher than a reflectance of any of the second light extraction elements, each of the first light extraction elements having a light transmittance that is lower than a light transmittance of any the second light extraction elements, each of the first light extraction elements having the same shape and size as any other one of the plurality first light extraction elements, and each of the second light extraction elements having the same shape and size as any other one of the plurality of second light extraction elements.

Abstract: In one embodiment, an overhead street light (a luminaire) is formed that has an asymmetric light intensity distribution, where the peak intensity is greatest along the direction of the street, lower directly across the street, and much lower on the house side of the street. Around the edge of a circular transparent light guide are white light LEDs that inject light into the light guide. To help control the asymmetry of the light intensity distribution, sawtooth-shaped grooves are formed in the light guide surface opposite to the light-emission surface and parallel to the street. Gaussian diffusers are used to partially diffuse the light. By proper selection of the grooves, the Gaussian diffuser, and the relative amounts of light emitted by LED segments around the light guide, the desired asymmetrical light intensity distribution is achieved while a direct view of the light exit surface appears as a uniform light.

Abstract: A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.

Abstract: An apparatus is disclosed including a light guide and a plurality of light emitting diodes (LEDs). The light guide includes a rear portion including a first edge, a second edge, and a rear edge. The first edge meets the rear edge at a first obtuse angle, and the second edge meets the rear edge at a second obtuse angle. The plurality of light emitting diodes (LEDs) disposed on the first edge, the second edge, and the rear edge, and it is arranged to produce an asymmetric light distribution pattern including a rear light emission and a forward light emission having a greater peak intensity than the rear light emission.

Abstract: A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.

Abstract: A method, apparatus, and system are disclosed for increasing light extraction efficiency in a light guide optical system. The light guide optical system may comprise a light emitting source. The light emitting source may be, for example, a light-emitting diode (LED) or plurality of LEDS. The light guide optical system may also comprise a light guide plate (LGP). The LGP may include light extraction features located on surfaces of the LGP. The LGP may also include a shaped injection surface on an input surface of the LGP. The shaped injection surface may be angled to deviate near-parallel light emitted from the LED to enable the near-parallel light emitted from the LED to be extracted from the LGP via the light extraction features. The shaped injection surface may be a split edge (i.e. a V-groove) or a curved edge.

Abstract: A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.

Abstract: A lighting device and method of forming the lighting device are provided. The lighting device includes a light guide, a lighting element having a light emitting diode (LED), and an in-coupling structure. The in-coupling structure includes one or more remote phosphor regions and one or more reflective regions. The in-coupling structure is integrally formed in a single piece. The in-coupling structure is affixed to the light guide and the lighting element, and is positioned between the light guide and the LED. An optional seal may be a part of the integrally formed in-coupling structure.

Abstract: A light emitting diode (“LED”) module is disclosed. The LED module includes a first LED tap and a second LED tap, the first tap being powered on for a longer amount of time than the second LED tap, based on an alternating current voltage. The LED module also includes a first LED package on which a first LED associated with the first LED tap and a second LED associated with the second LED tap are disposed. The LED module further includes a second LED package on which a third LED associated with the first LED tap and a fourth LED associated with the second LED tap are disposed.

Abstract: A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.