A fluorescent light tube retrofit with light emitting diodes (LEDs) that evenly distribute light to avoid bright spots is disclosed. One tube in the form of a conventional fluorescent tube includes two LEDs mounted to the tube on opposite sides of a single circumference of the tube. The LEDs can face the center of the tube, or the LEDs can be offset facing relative to the center of the tube. A reflecting surface can be disposed inside the tube to reflect light evenly toward an arc of the tube. Alternatively, at least one LED can be oriented to direct light into a light pipe that curves around the interior of the tube.

Light distribution using a light emitting diode assembly

A LED-based replacement light for a fluorescent socket is constructed such that an entirety of a radially outer portion of a tubular housing at least partially defined by a high-dielectric light transmitting portion is formed of a high-dielectric material. Forming a radially outer portion of the tubular housing of a high-dielectric material prevents a person handling the light from being shocked as a result of capacitive coupling occurring when the LED-based replacement light is installed one end at a time. A circuit board is in thermally conductive relation with the tubular housing, allowing for conduction of heat generated by the LEDs from a side of circuit board opposite the LEDs to the tubular housing for dissipation to the ambient environment.

Electric shock resistant l.e.d. based light

A method of forming a LED-based light for replacing a conventional fluorescent bulb in a fluorescent light fixture includes shaping an elongate sheet of highly thermally conductive material to fashion a heat sink. Shaping the heat sink allows fashioning the heat sink to define cover and end cap attachment structures, surfaces for mounting LEDs at various angles, and a high surface area to width ratio for dissipating heat.

Method of forming led-based light and resulting led-based light

An LED-based light tube for use in a conventional fluorescent fixture can feature a housing including a light transmitting portion. At least one electrical connector can be attached to the housing and configured for engagement with the conventional fluorescent fixture. At least one LED can be arranged to produce light in a direction toward the light transmitting portion. A sensor can be operable to detect a brightness level and output a corresponding signal. A controller can be in electrical communication with the at least one electrical connector and operable to control the at least one LED in response to the signal.

Light and light sensor

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Circadian friendly led light source

A light-emitting diode (LED) includes a heat sink ( 10 ) having a cross section along an axial direction thereof being U-shaped. The heat sink includes a substrate ( 102 ) and a sidewall ( 11 ) extending from an outer periphery of the substrate. A circuit board ( 40 ) is received in the heat sink and arranged on the substrate. At least one LED ( 30 ) is arranged on and electrically connected to the circuit board and thermally connected with the substrate of the heat sink. A plurality of fins ( 100 ) extend outwardly from an outer surface ( 110 ) of the sidewall of the heat sink. Each fin has a plurality of branches ( 100 a, 100 b ) being connected together at the outer surface of the sidewall and being spaced from each other at outer-peripheries thereof.

Ming-Wu Zhu

Papers

Light-emitting diode lamp