Patent Application
20190249857
The present application relates generally to heat dissipation systems. More particularly, the present application relates to an assembly that efficiently dissipates heat from a LED.
Light emitting diodes (“LEDs”) are energy efficient devices that emit light. LEDs are typically more durable and require less power than conventional lighting technology, making them ideal for lights frequently in use, such as, for example, street lights. However, LEDs produce heat as a by-product of light production and such heat can damage the surrounding structure or LED if it not effectively dissipated.
Currently, LED heat dissipation assemblies include a heat sink with, for example, fins to dissipate the heat from the lighting device to the environment. The heat sink is typically connected to the LED so heat is conducted directly or indirectly from the LED to the heat sink, and ultimately, away from the lighting device.
Conventional heat dissipation assemblies require direct or near direct connection between the heat sink and LED to effectively receive and dissipate heat. The heat sink must also be exposed to the outside atmosphere and/or weather to disperse excess heat away from the LED device, thus causing concerns of corrosion, leakage, and the like. These spatial constraints, in addition to the necessary bulk of the heat sink, limit the locations for other parts of the LED device and inefficiently dissipate heat.
The invention broadly comprises a lighting device that includes a heat sink coupled to a heat dissipation structure. The heat dissipation structure can include a series of heat conduits, or pipes, that are effectively disposed near a lighting element, such as, for example, a an LED device, to receive and transfer heat from the lighting element. The heat conduits conduct heat from the lighting element across a heat sink, which then emits the heat away from the lighting device, to protect the internal components of the lighting device, while still enabling distal placement of the heat sink relative to the lighting element.
In an embodiment, the present invention broadly comprises a lighting device including a light emitting structure, a housing adapted to house the light emitting structure and a heat dissipation structure coupled to the housing. The heat dissipation structure may include a heat sink plate defining at least one groove and at least one mounting surface to receive the light emitting structure. The heat dissipation structure may also include at least one conduit conductively coupled to the heatsink plate and disposed in the groove at a position to receive heat emitted from the light emitting structure.
In another embodiment, the present invention broadly comprises a heat dissipation structure including a heat sink having a lower surface defining at least one mounting surface located opposite a groove. At least one light-emitting device may be affixed to the at least one mounting surface and at least one heat conduit may be conductively coupled to the heat sink. The at least one heat conduit may be adapted to transfer heat away from the at least one light emitting device.
For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.
While the present invention is susceptible of embodiments in many different forms, there is shown in the drawings, and will herein be described in detail, embodiments of the invention, including a preferred embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the present invention and is not intended to limit the broad aspect of the invention to any one or more embodiments illustrated herein. As used herein, the term “present invention” is not intended to limit the scope of the claimed invention, but is instead used to discuss exemplary embodiments of the invention for explanatory purposes only.
In an embodiment, the present invention broadly comprises a lighting device that includes a light emitting source, such as, for example, a chip-on-board (“COB”) light emitting diode (“LED”) device, a heat sink and conduits or heat pipes operatively arranged and connected to the heat sink and disposed above an LED device in a manner designed to effectively and efficiently draw heat away from the light emitting source. In an embodiment, the increased heat transfer capabilities of the heat pipe described may improve the light output of the design. Additionally, the advantageous design may reduce heat sink size and accordingly, the material reduction may provide weight and cost reduction. In an embodiment, the heat sink assembly consists of copper heat pipes imbedded into grooves found on the die cast aluminum heat sink.
Referring to
Referring to
The heat pipe 215 may be made of any material, and may be any structure that allows for the transfer of heat from a heat emitting structure through the heat sink plate 105. As shown, the heat pipe 215 may substantially linear and made from copper. The heat pipe 215 may be substantially cylindrical, round or rectangular depending on the definition of the grooves 110. The heat pipe 215, as shown, may be tubular in nature, i.e., can be hollow inside, to allow for even greater surface area to dissipate heat. In this manner, the heat pipe 215 can absorb heat from the heat source and direct the heat away from the source through and across the heat sink plate 105. According to one embodiment, the heat pipe 215 may be flattened or have substantially flat portions along its length. The flattened portions of the heat pipe 215 may provide greater surface area at the point of contact with the heatsink 105. According to yet another embodiment, the heat pipe 215 may be coated with a wicking agent or other coating to improve heat transfer from the heat pipe 215 to a vapor or gas which may then be expelled via the hollow channel of the heat pipe 215.
In an embodiment, the heat pipes 215 may be affixed to the heatsink plate 105 using a conductive adhesive, such as an aluminum filled, heat sink bonding resin. The resin or epoxy may be mixed with a hardener further enhancing the adhesive bond formed between the heat sink plate and the heat pipe 215.
In operation, when one or more COB LED devices are powered, heat may be generated that, unless drawn away from the electronics of the LED, may disrupt or damage the COB and surrounding components. According an embodiment of the present invention, heat from the operation of the COB LED may be drawn upwardly through the heat sink plate 105 and into the heat pipe 215 which may be formed from a superior conductor than the heat-sink material. For example, a die-cast aluminum heat sink plate 105 may draw heat from the COB LED 300 upward into heat pipes 212 made of copper. Copper, being a superior conductor of heat compared to aluminum, may draw the heat from the heat sink plate 105 surrounding the COB LED 300 and dissipate the heat across the heat pipe and portions of the heat sink plate 105 leading away from the COB, and thereby avoiding excessive heat localized on or around the COB LED 300, the mounting surface, 320, and lens 430.
While aspects of the invention are described herein using COB LEDs, it will be appreciated that other lighting devices and heat sources may be implemented without deviating from the scope of the present disclosure. Additionally, while the heat sink assembly 500 described herein is shown including mounting surfaces for four lighting sources, it will be appreciated that other configurations of light sources, heat pipes and heat sink plates are within the scope of the disclosure, particularly those designed and configured to dissipate heat generated by the light source in the manner described herein.
As discussed herein, the term “coupled” is intended to refer to any connection, direct or indirect, and is not limited to a direct connection between two or more elements of the disclosed invention. Similarly, “operatively coupled” is not intended to mean any direct connection, physical or otherwise, and is merely intended to define an arrangement where two or more elements communicate through some operative means (e.g., through conductive or convective heat transfer, or otherwise).
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of Applicant's contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
