Bulb Tle
Bulb Tle
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 TERRALUX EXTREME LED UPGRADE BULB FOR AA MAGLITE FLASHLIGHTS 140 LUMENS TLE5EX  US $14.95
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A led gu10 bulb lighting device comprises: a thermally conducting body having an at least one opening that connects with a cavity within the body and a plurality of LEDs mounted in thermal communication with a face of the body and positioned around the opening.
One or more passages pass through the body from the cavity to an outer surface of the body and are configured such that in operation air moves through the cavity by thermal convection thereby to provide cooling of the body. Each passage is configured in a direction that extends in a direction at an angle of about 45° to a line that is parallel with the axis of the body toward the outer surface of the body away from the face. The body can be configured such that its outer surface has a form factor resembling an incandescent light bulb or halogen reflector lamp.
A light emitting diode lighting device comprising:a thermally conducting body having at least one opening that connects with at least one cavity within the body;a plurality of light emitting diodes mounted in thermal communication with a face of the body and positioned around the opening; andat least one passage passing through the body from the cavity to an outer surface of the body and configured such that in operation air moves through the at least one cavity by thermal convection thereby to provide cooling of the body.
White light generating LEDs, "white LEDs", are a relatively recent innovation and offer the potential for a whole new generation of energy efficient lighting systems to come into existence. It is predicted that white LEDs could replace filament (incandescent), fluorescent and compact fluorescent light sources due to their long operating lifetimes, potentially many 100,000 of hours, and their high efficiency in terms of low power consumption. It was not until LEDs emitting in the blue/ultraviolet part of the electromagnetic spectrum were developed that it became practical to develop white light sources based on LEDs.
As taught, for example in U.S. Pat. No. 5,998,925, white LEDs include one or more phosphor materials, that is photo-luminescent materials, which absorb a portion of the radiation emitted by the LED and re-emit radiation of a different color (wavelength). Typically, the LED chip or die generates blue light and the phosphor(s) absorbs a percentage of the blue light and re-emits yellow light or a combination of green and red light, green and yellow light or yellow and red light. The portion of the blue light generated by the LED that is not absorbed by the phosphor is combined with the light emitted by the phosphor to provide light which appears to the human eye as being nearly white in color.
To date high brightness white LEDs have been used to replace conventional incandescent light bulbs, halogen reflector lamps and fluorescent lamps. Most lighting devices utilizing LEDs comprise arrangements in which a plurality of LEDs replaces the conventional light source component.
For example it is known to replace the filament assembly of an incandescent light bulb with white LEDs or groups of red, green and blue emitting LEDs. WO 2006/104553 teaches such an LED light bulb in which a plurality of white LEDs are mounted on a front face, back face and top edge of a generally rectangular substrate (printed circuit board) such that their combined light emission is generally spherical and replicates the light output of a conventional incandescent light bulb.
The substrate is enclosed in a light transmissive cover and mounted to a connector base (e.g. screw cap) for coupling the bulb to a power source. U.S. Pat. No. 6,220,722 and U.S. Pat. No. 6,793,374 disclose an LED lamp (bulb) in which groups of white LEDs are mounted on the planar faces of a polyhedral support having at least four faces (e.g. cubic or tetrahedral). The polyhedral support is connected to a connector base by a heat dissipating column. The whole assembly is enclosed within a transparent bulb (envelope) such that it resembles a conventional incandescent light bulb.
A problem that needs addressing in the development of practical LED lighting devices, in particular compact devices that can be used as direct replacements for incandescent light bulbs, is adequately dissipating the heat generated by the large number of LEDs required in such devices and thereby preventing overheating of the LEDs. Various solutions have been proposed. One solution is to mount the LEDs on a heat sink which comprises the body of the device in which the heat sink is mounted to a conventional connector cap enabling the device to be used in a conventional lighting socket. As for example is described in U.S. Pat. No. 6,982,518 the heat sink can include a plurality of latitudinal fins to increase the surface area of the heat sink.
A transparent or translucent domed cover can be provided over the LEDs such that the device bears a resemblance to a conventional led gu10 bulb. In U.S. Pat. No. 6,982,518 the form factor of the heat sink is shaped to substantially mimic the outer surface profile of an incandescent light bulb.