Patent Application
20130039074
The invention disclosed herein generally relates to luminaires and, more specifically, to light emitting diode (LED) luminaires with convection cooling.
Generally, a light emitting diode (LED) is believed to be future of lighting because of high efficiency and low environmental impact. LED luminaire is a device that utilizes LEDs as a source of illumination, in which current flowing in one direction through a junction region comprising two different semiconductors results in electrons and holes coupling at the junction region and generating a light beam. Further, the LEDs are resistant to shock and have an almost endless lifetime under specific conditions.
Owing to the aforementioned reasons and very little energy consumption during operation, LED luminaires have replaced conventional incandescent lamps in many products, such as decoration lamps, advertisement signs or traffic signs. The LEDs need to be mechanically secured and electrically connected inside a package that often contains a phosphor layer above the LED chip for color conversion and sometimes contains a lens above the phosphor layer.
The following detailed description of embodiments of the invention will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the invention, there is shown in the drawings, embodiments which are presently preferred. In the drawings, the left-most digit(s) of a reference number indicates the drawing in which the reference number first appears. The same reference numbers have been used throughout the drawings to indicate similar elements of the drawings.
It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
The invention has been developed in response to the present state of the art and, in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available apparatus and methods.
Detailed embodiments of the invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather to provide an understandable description of the invention.
Typically, light emitting diode (LED) modules are used in an LED lamp. Known implementations of LED modules in the LED lamp make use of a plurality of individual LEDs to generate light that is ample and of satisfactory spatial distribution. Further, the LEDs require very little energy consumption during operation. The LEDs are typically shipped without a printed circuit board (PCB) and therefore have to be mounted on PCBs. Presently, the LED lamps as replacement of fluorescent tubes predominantly comprise an array of LEDs mounted on a rectangular board placed inside a transparent tube or encapsulated by a transparent cover. These LED lamps, have LEDs encapsulated without adequate ventilation between the open space outside the luminaire and the encapsulated space surrounding the LEDs. Although the LED lamps can illuminate with very little power supply, the temperature will become higher when illumination and since there is no ventilation, heat dissipation from LEDs is ineffective, which reduces performance and lifetime of LEDs.
The terms “a” or “an,” as used herein, are defined as one or more than one. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open transition). The term “coupled” or “operatively coupled,” as used herein, is defined as connected, although not necessarily directly and/or mechanically.
In various embodiments of the specification, a luminaire is disclosed. The term “luminaire” used herein refers to a light fixture, light fitting, that may be used to create artificial light by use of an electric lamp. The luminaire may include one or more light sources of same or different types. The luminaire may include an enclosure defining a cavity therein. In one embodiment, a luminaire is provided for being configured to be installed at a fixed location and configured to allow convective airflow. This embodiment includes an enclosure defining a cavity therein and having at least one surface. The luminaire may include a plurality of apertures disposed on the surface and configured to allow air to flow there through, wherein there exists a height differential between one aperture and another aperture. The luminaire may further include a semiconductor light source assembly for being received in the cavity, wherein light emitting surface of the semiconductor light source assembly is exposed to the air flowing through the enclosure, and wherein convective air flow takes place due to height differential between two apertures.
In another embodiment, the enclosure may include more than one surface, such as a first surface and a second surface, such that the second surface is opposite to the first surface. Further, the first surface may be configured to be attached to a fixed location, such as a ceiling. The luminaire may further include a plurality of apertures disposed on the first surface and the second surface of the enclosure. In other words, a first set of apertures from the plurality of apertures may be configured on the first surface of the enclosure and a second set of apertures from the plurality of apertures may be configured on the second surface. Accordingly, there exists a height differential between the first set of apertures disposed on the first surface and the second set of apertures disposed on the second surface.
In addition, the luminaire may include a semiconductor light source assembly, such as a plurality of LEDs for being received in the cavity as defined by the enclosure. In an implementation, a light emitting surface of the semiconductor light source assembly is exposed to the air flowing through the enclosure. Further, due to the height differential between the first surface and the second surface, convective air flow takes place through the first set of apertures and the second set of apertures. The term LED may refer to an LED package, such as a white LED may typically include an LED package comprising blue-light-emitting LED chips and a phosphor layer to convert blue lights into longer wave length lights. Further, a “semiconductor light source assembly” refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources.
The LED luminaire may be configured to create an efficient system for heat dissipation. The LED luminaire as disclosed in the invention is ventilated by the plurality of apertures, such that the cavity defined by the enclosure of the luminaire is not a closed system. This may facilitate in exchange of air, in a manner that the air heated up by LEDs exits the luminaire and cold air may enter the luminaire. In preferred embodiments, metal-core PCBs (MCPCB) may be used.
In one embodiment, a luminaire is provided that may be configured to be installed at a fixed location. The luminaire may include an enclosure defining a cavity therein. The enclosure may include a first surface and a second surface opposite to the first surface. The first surface may be configured to attach to the fixed location, such as a ceiling. The luminaire may further include a plurality of apertures disposed on the first surface and the second surface of the enclosure. The plurality of apertures may be configured to allow air to flow there through. In addition, there exists a height differential between a first set of apertures from the plurality of apertures disposed on the first surface and a second set of apertures disposed on the second surface. Furthermore, the luminaire may further include a semiconductor light source assembly for being received in the cavity. The light emitting surface of the semiconductor light source assembly may be exposed to the air flowing through the enclosure. Due to height differential between the plurality of apertures configured on the first surface and the second surface of the enclosure, the heat generated by the semiconductor light source assembly may be dissipated and air flow through convection takes place.
The luminaire 100 may include an enclosure 102 that may be configured to define a cavity (not shown) therein. The enclosure 102 may include a first surface 104 and a second surface 106 that may be configured opposite to the first surface 104. In an embodiment, the first surface 104 of the enclosure 102 may be configured to attach to a fixed location, such as a ceiling 108. The luminaire 100 may further include a plurality of apertures that may be disposed on the enclosure 102. Specifically, a first set of apertures 110 from the plurality of apertures may be disposed on the first surface 104 of the enclosure 102 and a second set of apertures 112 from the plurality of apertures may be disposed on the second surface 106 of the enclosure 102. The plurality of apertures may be configured to allow air to flow there through.
In a preferred embodiment, the luminaire 100 may be installed at a fixed location, such as a ceiling and a wall. Further, the luminaire may be oriented with respect to the ceiling, such that at heights, different sections of air flow paths are fixed, and the height differential along the paths determines the direction of convective air flow as hot air rises up, with certain apertures serving as air outlet and the other apertures as air inlet.
As may be evident from
As shown in
Referring to
In use, the air from the room may enter the luminaire 200 from the second set of apertures 212. As mentioned earlier, the light emitting surface of the LEDs is exposed to the air flow through the cavity defined by the enclosure. Accordingly, as the air comes in contact with the light emitting surface of the LEDs the heat of the LEDs may get transferred to the air. As a result, the air may become hot and the heated air may rise up in the cavity, due to pressure difference. Further, as there exists a height differential between the first surface 204 and the second surface 206, the hot air may escape to outside from the first set of apertures 210 located on the first surface 204 of the enclosure and giving rise to convective air flow. It will be evident to a person skilled in the art that slanted surfaces, such as the first surface 204 and the second surface 206 as illustrated in
It will be evident to a person skilled in the art that shape and orientation of the LED panel and the lens assembly may be different. For example, the first surface 402 and the second surface 408 may be curved. It will be understood that irrespective of the shape of the enclosure, a height differential may be required to exist between the inlet apertures, such as apertures 410 and outlet apertures, such as apertures 412. This may ensure that convective air exchange occurs between the cavity and the outside. It will also be evident that the apertures 410 for allowing the air to enter the enclosure 402 may are be located in other regions of the second surface 408, such as a side region.
In another embodiment, the luminaire, such as the luminaire 100 and the flat surface luminaire 300 may be used as a retrofit kit that may be mounted below a housing of a recessed fluorescent fixture. In yet another embodiment, the luminaires 100 and 300 as shown in
It will be evident to a person skilled in the art that the invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application claims the priority of U.S. provisional application No. 61/521,373, filed Aug. 8, 2011. The application is incorporated herein by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 61521373 | Aug 2011 | US |
