Patent Application
20120002423
The present application relates to lamps and more particularly to a lamp including a truncated reflector cup.
Reflector-type lamps, such as multi-faceted reflector (MR) lamps and parabolic aluminized reflector (PAR) lamps, are well-known and are used in a wide variety of applications. In general, a reflector-type lamp includes a light source disposed adjacent to a reflector cup. The light source may include one or more light emitting diodes (LEDs), a gas discharge light source such as a fluorescent tube (e.g., in a compact fluorescent (CFL) lamp), and/or a high-intensity discharge (HID) light source. The interior surface of the reflector cup may be provided with a reflective coating and/or may be formed from a reflective material such as aluminum. Light from the light source may be imparted on the interior surface of the reflector cup and reflected outward from an end of the reflector cup. The interior surface of the reflector cup may take a variety of shapes, e.g. generally paraboloid, ellipsoid, sphero-ellipsoid, etc., and controls the direction and spread of light cast from the lamp.
In some applications, it is desirable to more narrowly focus lamp output to provide a small beam angle. However, in a small form factor configuration, such as a conventional MR16 configuration, the smallest obtainable beam angle is limited by the ratio between the reflector cup surface area and the light source surface area. If conventional remote phosphor technology is used on a phosphor plate/dome, the phosphor plate/dome effectively becomes the light source, which is large compared with LED chips. The maximum CPCB in such a configuration is limited by dimensional restraints. Also, if a high light output level is desired in a small form factor lamp, thermal management may be an issue due to the limited amount of space available for effective heat sinking.
Embodiments of the present invention provide for one or more truncated reflector cups, as described in greater detail herein. Accordingly, a lamp including truncated reflector cups according to embodiments described herein may be configured to provide a smaller beam angle and higher maximum CBCP than a lamp including a full reflector cup in a package of comparable size. In addition, heat generated by light engines in a system according to embodiments described herein may be dissipated by base plates and a heat spreader without significantly adding to the size of the assembly.
In an embodiment, there is provided a lamp assembly. The lamp assembly includes first and second truncated reflector cups; at least one base plate disposed between the first and second truncated reflector cups; and a light engine disposed on a top surface of the at least one base plate, the light engine configured to emit light to be reflected by one of the first and second truncated reflector cups.
In a related embodiment, the first truncated reflector cup may have a first reflector cup side surface intersecting first and second associated end surfaces, and the second truncated reflector cup may have a second truncated reflector cup side surface intersecting first and second associated end surfaces, and the at least one base plate may be disposed between the first reflector cup side surface and the second reflector cup side surface. In a further related embodiment, the first reflector cup side surface may be in contact with the top surface of the at least one base plate. In another further related embodiment, the at least one light engine may include a light emitting diode having an emitting surface, and the first reflector cup side surface may be in a plane positioned closer to the emitting surface than the top surface of the at least one base plate.
In another related embodiment, the at least one base plate may include a thermally conductive material. In yet another related embodiment, the top surface of the base plate may include a reflective surface configured to reflect light incident thereon. In still another related embodiment, the assembly may include first and second ones of the base plates. In a further related embodiment, the light engine may be disposed on a top surface of the first base plate and may be configured to emit light to be reflected by the first truncated reflector cup, and the assembly may include a second light engine disposed on a top surface of the second base plate, the second light engine being configured to emit light to be reflected by the second truncated reflector cup.
In yet still another related embodiment, the first and second truncated reflector cups may have associated generally semi-paraboloid interior surfaces. In still yet another related embodiment, the assembly may further include a housing coupled to the first and second truncated reflector cups and at least one electrical lead extending from the light engine, through a bottom of at least one of the first and second truncated reflector cups and into the housing. In another related embodiment, the assembly may further include a housing coupled to the first and second truncated reflector cups and a ballast circuit disposed in the housing to provide an electrical output to the light engine. In yet another related embodiment, the assembly may further include a heat spreader thermally coupled to the at least one base plate.
In another embodiment, there is provided a lamp assembly. The lamp assembly includes first and second truncated reflector cups, the first truncated reflector cup having a first reflector cup side surface intersecting first and second associated end surfaces, and the second truncated reflector cup having a second truncated reflector cup side surface intersecting first and second associated end surfaces; at least one base plate disposed between the first truncated reflector cup side surface and the second truncated reflector cup side surface, the at least one base plate having a reflective top surface configured to reflect light incident thereon; and at least one light engine disposed on the top surface of the at least one base plate, the light engine comprising at least one light emitting diode having an emitting surface positioned to emit light toward the first truncated reflector cup, the first reflector cup side surface being in a plane positioned closer to the emitting surface than the top surface of the at least one base plate.
In a related embodiment, the at least one base plate may include a thermally conductive material. In a further related embodiment, the assembly may include first and second ones of the base plates. In a further related embodiment, the light engine may be disposed on a top surface of the first base plate, and the assembly may include a second light engine disposed on a top surface of the second base plate, the second light engine being configured to emit light to be reflected by the second truncated reflector cup.
In another related embodiment, first and second truncated reflector cups may have associated generally semi-paraboloid interior surfaces. In yet another related embodiment, the assembly may further include a housing coupled to the first and second truncated reflector cups and at least one electrical lead extending from the light engine, through a bottom of at least one of the first and second truncated reflector cups and into the housing. In still yet another related embodiment, the assembly may further include a housing coupled to the first and second truncated reflector cups and a ballast circuit disposed in the housing to provide an electrical output to the light engine.
In another embodiment, there is provided a method of assembling a lamp. The method includes providing first and second truncated reflector cups; positioning at least one base plate between the first and second truncated reflector cups; and providing a light engine on a top surface of the at least one base plate, the light engine configured to emit light to be reflected by one of the first and second truncated reflector cups.
The foregoing and other objects, features and advantages disclosed herein will be apparent from the following description of particular embodiments disclosed herein, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles disclosed herein.
In general, a lamp according to embodiments described herein includes at least one truncated reflector cup with a light engine configured to emit light that is reflected by the interior surface of the truncated reflector cup and out of an open end of the truncated reflector cup. As used herein, the term “reflector cup” refers to a reflector having: a first end that receives at least a portion of a light engine, the light emitted therefrom, or one or more electrical leads therefor; an opposed second end from which light emitted by the light engine may be cast from the lamp; and an interior surface with a substantially continuous cross-section taken in a plane parallel to the first or second end and configured to reflect light from a light engine toward the second end. The term “reflector cup” thus includes, but is not limited to known parabolic, elliptical and sphero-elliptical reflector configurations including those with faceted interior surfaces. The term “truncated reflector cup” means a portion of a reflector cup, as may be realized, for example, by dividing a reflector cup along a plane intersecting the first end and the second end. A truncated reflector cup may thus be configured as one-half of a reflector cup, but may be more or less than half of a reflector cup, for example but not limited to, one-third of a reflector cup, one-fourth of a reflector cup, and so on. Thus, in some embodiments, a truncated reflector cup may have a semi-paraboloid or semi-elipsoid shape, among other shapes. Further, in some embodiments, the second end from which light is emitted by the light engine may not be entirely opposed to the first end (i.e., 180° degrees or approximately 180° away from the first end), but rather may be only partially opposed (for example but not limited to 170° and/or 190°, or approximately 170° or 190°), and alternatively or additionally, may be perpendicular to the first end, and alternatively or additionally, may be anywhere in the range of degrees from 0 to 360 with respect to the first end. For example, the light may come partially or entirely out of a side of a lamp, as opposed to the top or bottom (wherein the top or bottom is defined as the location that is opposite the light engine).
According to embodiments described herein, the interior surface of the reflector cup may terminate at a side surface that intersects first and second end surfaces. The light engine may be disposed on a base plate positioned adjacent to and substantially parallel to the side surface. The lamp may include first and second ones of the truncated reflector cups positioned with side surfaces in opposed relationship and with one or more base plates positioned therebetween. At least one light engine may be disposed on each base plate to emit light toward each truncated reflector cup, or a single light engine may be provided to emit light toward only one of the truncated reflector cups. Alternatively, or additionally, in embodiments where there are more than two truncated reflector cups, there may be a number of light engines provided that is one less than the number of truncated reflector cups, two less, three less, and so on. A truncated reflector cup configuration according to embodiments described herein produces a smaller beam angle compared to full-reflector cup configuration of the same size. A truncated reflector cup configuration according to embodiments described herein also allows for an enlarged heat spreader compared to a full reflector cup configuration of the same size.
The illustrated embodiment 400 includes a first truncated reflector cup 402, a second truncated reflector cup 404, first 406 and second 408 base plates, first 410 and second 412 light engines and a heat spreader 414. Each truncated reflector cup 402, 404 includes an associated interior surface 416, 418 forming a portion of a paraboloid, i.e. each truncated reflector cup has a separate generally semi-paraboloid interior surface. For embodiments where a truncated reflector cup is not semi-parabolic, but rather of an alternative shape (for example, semi-ellipsoid), the interior surface of the truncated reflector cups, in combination, instead forms that alternative shape, and individually, each truncated reflector cup would form a portion of that alternative shape. The interior surface 416, 418 of each reflector cup terminates at a side surface 420, 422, respectively. The side surface 420 of the first truncated reflector cup 402 intersects first 424 and second 426 end surfaces of the first truncated reflector cup 402. The side surface 422 of the second truncated reflector cup 404 intersects first 428 and second 430 end surfaces of the second truncated reflector cup 404.
The first 406 and second 408 base plates are positioned with top surfaces 432, 434, respectively, thereof adjacent and substantially parallel to the side surfaces 420, 422 of the first and second truncated reflector cups, respectively, so that the base plates 406 and 408 are positioned between the truncated reflector cups 402, 404. The top surfaces 432, 434 of the base plates 406, 408 may contact the side surfaces 420, 422, respectively, of the truncated reflector cups 402, 404 or may be spaced therefrom. The first 410 and second 412 light engines are disposed on the top surfaces 432, 412, respectively, of the base plates 406, 408 and the back surfaces 436, 438 of the base plates 402, 404, respectively, are positioned adjacent each other in an opposed facing relationship. The back surfaces 436, 438 of the back plates may be spaced from each other, or may be in direct contact with each other.
The first 410 and second 412 light engines may take any known light engine configuration, and/or may include any known light source configuration such as one or more LEDs (with or without a remote phosphor element), a gas discharge light source such as a fluorescent tube (e.g., in a compact fluorescent (CFL) lamp), and/or a high-intensity discharge (HID) light source, among others. As used herein, “LED” means any solid state light source, including light emitting diode(s) (LED or LEDs), organic light emitting diode(s) (OLED or OLEDs), and the like. The singular term “LED” may thus refer to a single LED die on a chip having one or more LED dies, and/or to the chip itself which contains one or more LED dies, and/or to an array (i.e., plurality) of chips, each including one or more LED dies, grouped together. In any of these instances, phosphor and/or phosphors as well as optics and other associated components may also be present. In the illustrated embodiment of
The base plates 406, 408 may be configured as printed circuit boards (PCBs) including electronics and/or conductive traces and electrical leads thereon receiving an electrical input and energizing the light engines 410, 412. The base plates 406, 408 may be thermally conductive and may be thermally coupled to the heat spreader 414 and, optionally, directly to the end surfaces 424, 428 at the first end, i.e. end 502 in
The heat spreader 414 may include a known thermally conductive material for conducting and dissipating heat from the base plates 406, 408 and/or the truncated reflector cups 402, 404. Heat generated by the LEDs 440, 442 and electronics on the base plates 406, 408 may thus be distributed and dissipated by the base plates 406, 408 and the heat spreader 414. The top surfaces 432, 434 of the base plates 406, 408, respectively, may be reflective so that light emitted by the light engines 410, 412 and/or reflected from the interior surfaces 416, 418 of the truncated reflector cups 402, 404 is reflected from the top surfaces 432, 434 of the base plate and toward the second end, i.e. end 504 in
Although the illustrated embodiment shown in
In the illustrated embodiment shown in
Although the illustrated embodiment 700 of
Turning now to
The thickness of the heat spreader portions 420, 422 may be selected to space the side surfaces 420, 422 of the truncated reflector cups 402, 404 from the top surfaces 432, 434 of the base plates 406, 408 such that the top surfaces 434, 434 lie in a plane closer to the emitting surfaces 444, 446 of the light engines 410, 412 than the top surfaces 432, 434 of the base plates 406, 408, as described in connection with
The base plates 406, 408 may be secured to each other and to the truncated reflector cups 402, 404 and/or may be secured to the base plates 406, 408 by associated fasteners 1102, as shown for example in
Electrical leads 1024, 1026 may extend from the light engines 410, 412 on the base plates, through corresponding openings 1030 in flat bottom portions 1032, 1034 of the truncated reflector cups 402, 404 and into a cavity 1036 defined by the housing. The electrical leads 1024, 1026 may be coupled to an optional known ballast circuit 1040. Input electrical leads 1042, 1044 may be coupled to the ballast circuit 1040 and extend outward from the housing 1006 for coupling an electrical power source 1046 to the ballast circuit 1040. As is known, the ballast circuit 1040 may receive an electrical input from the power source 1046 and convert it to a stable output for driving the light engines 410, 412. In another embodiment, a ballast circuit 1040 may be positioned remotely from the housing 1006 and the output of the ballast circuit 1040 may be coupled to the input leads 1042, 1044 with the electrical leads 1024, 1026 coupled directly to the input leads 1042, 1044.
Unless otherwise stated, use of the word “substantially” may be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems.
Throughout the entirety of the present disclosure, use of the articles “a” or “an” to modify a noun may be understood to be used for convenience and to include one, or more than one, of the modified noun, unless otherwise specifically stated.
Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, may be understood to so communicate, be associated with, and or be based on in a direct and/or indirect manner, unless otherwise stipulated herein.
Although the methods and systems have been described relative to a specific embodiment thereof, they are not so limited. Obviously many modifications and variations may become apparent in light of the above teachings. Many additional changes in the details, materials, and arrangement of parts, herein described and illustrated, may be made by those skilled in the art.
The present application claims priority of U.S. Provisional Application No. 61/360,423, filed Jun. 30, 2010, the entire contents of which are hereby incorporated by reference.
This invention was made with U.S. Government support under DOE Cooperative Agreement No. DE-EE0000611, awarded by the U.S. Department of Energy. The U.S. Government may have certain rights in this invention.
| Number | Date | Country | |
|---|---|---|---|
| 61360423 | Jun 2010 | US |
