Not applicable.
1. Field of the application
The application relates generally to lighting devices, and more particularly to LED-based lighting devices.
2. Background
Most lighting currently in use includes either incandescent light bulbs or fluorescent light bulbs. An incandescent light bulb typically comprises a base, a glass shell, a thin filament which is normally a thin tungsten filament within the shell, and an inert gas within the shell. When an electric current passes through the filament and heats it up to an extremely high temperature (from about 2000° C. to about 3000° C. depending on the filament type, shape, size, and amount of current passed through), heat radiation occurs and visible light is produced. However, the process is considered highly inefficient, as over 98 percent of the energy is emitted as invisible infrared light(or heat). Also, the typical lifespan of an incandescent bulb is limited to about 1,000 hours.
A fluorescent light bulb is filled with gas containing low-pressure mercury vapor and an inert gas such as argon or xenon. Typically, the inner surface of the bulb is coated with a fluorescent coating made of various blends of metallic and rare-earth phosphorus salts. When electricity passes through mercury vapor, the mercury vapor produces ultraviolet light (“UV” light). The ultraviolet light is then absorbed by the phosphorus coating inside the bulb, causing it to glow, or to fluoresce. While the heat generated by fluorescent light is much less than its incandescent counterpart, efficiencies are still lost in generating the ultraviolet light and converting this light into visible light. In addition, fluorescent bulbs are typically more expensive than incandescent bulbs, but have longer life spans up to about 10,000 hours.
Light emitting diodes (“LEDs”) are, in general, miniature semiconductors that employ a form of electroluminescence resulting from the electronic excitation of a semiconductor material, which produces visible light. Typically, LEDs have high durability and a long life span up to about 100,000 hours. The LED generates less heat and less energy loss than incandescent lights and fluorescent lights, thereby reducing the overall electricity used. In addition, LEDs, being solid state devices, require much less space. However, LEDs are subject to thermal damage or destruction at temperatures that are much lower than those tolerated by incandescent bulbs. LEDs are susceptible to damage at temperatures exceeding about 150° C. (about 423°K).
Unlike incandescent and fluorescent lights, LEDs ordinarily produce light in a narrow, well defined beam. In other words, LEDs are directional light emitters. While this is desirable for many applications, the broader area illumination afforded by incandescent and fluorescent lights are also often desired. Currently available devices i incorporate multiple LEDs placed along planar substrates such as ceramic substrates. Unfortunately, the area of illumination is substantially limited to the directional beams of light as emitted from each individual diode (see the exemplary light spread A-A at
Also, ceramic substrates are used because the LEDs have thermal and electrical paths that come in contact with each other. For example, an LED may have electrical contacts on both top and bottom surfaces so that when the LED is mounted to a substrate, both heat and electricity may pass to the substrate. Thus, the ceramic substrate provides electrical insulating properties while allowing some heat to pass. Unfortunately, the ceramic substrate doesn't provide a very efficient thermal path so that heat generated by closely spaced LED chips may degrade light output. To facilitate heat dissipation, the ceramic substrate may be mounted to an aluminum heat spreader, which in turn is mounted to an additional heat sink. Such arrangements are costly and complicated to manufacture.
Accordingly, there is a need in the art for improvements in LED devices to provide broader illumination, increase light output, while providing efficient heat dissipation.
It has been discovered that a non-planar LED substrate may be provided to expand the surface area of light emitted onto a target surface beyond the area of light provided by a planar LED substrate. A non-planar LED substrate is also effective for providing greater heat dissipation beyond that provided by a planar LED substrate constructed from like material(s). Heretofore, such a desirable achievement has not been considered possible, and accordingly, this application measures up to the dignity of patentability and therefore represents a patentable concept.
Before describing the invention in detail, it is to be understood that the present light assembly and method are not limited to particular embodiments. 5 It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification, the phrase “target surface” refers to a surface to be illuminated by a light source including the light assembly of this application.
In one aspect, the application provides a light assembly including a nonplanar substrate surface with an array of light emitting diodes thereon.
In another aspect, the application provides a light assembly including an array of light emitting diodes affixed to a non-planar surface of a substrate of the light assembly.
In another aspect, the application provides a light assembly having a convex substrate surface including an array of light emitting diodes affixed thereto.
In another aspect, the application provides a light assembly including an array of light emitting diodes affixed to a non-planar surface of a substrate of the light assembly, wherein each LED emits light directionally in a non-parallel relationship to light being emitted from the remaining LEDs of the light assembly.
In another aspect, the application provides a light assembly operationally configured to dissipate heat.
In another aspect, the application provides a light assembly including a substrate for receiving light emitting diodes thereon, the substrate being set apart from a heat sink of the light assembly.
In another aspect, the application provides a light assembly including a heat sink having a plurality of apertures there through.
In another aspect, the application provides a light assembly including an array of light emitting diodes disposed along the outer surface of a non-planar substrate, the light assembly being operationally configured to broaden the area of illumination across a target surface beyond the area of illumination for the same type LEDs when disposed along a planar surface of a substrate.
In another aspect, the application provides a light assembly including an array of light emitting diodes disposed along a non-planar surface, the light assembly being operationally configured to maintain the temperature of each LED below about 40.6° C. (about 105° F.).
In another aspect, the application provides a surface substrate for affixing LEDs, wherein the curvature of the surface substrate may be altered to either lessen or broaden the intended area of illumination upon a target surface.
In another aspect, the application provides a light assembly including a non-planar substrate surface with an array of light emitting diodes thereon, the substrate comprising a reflective surface.
In another aspect, the application provides a light assembly including a planar heat sink operationally configured to dissipate heat received from a non-planar substrate including an LED array thereon.
In another aspect, the application provides a light assembly including a planar heat sink connected to a non-planar substrate for mounting LEDs, wherein the heat sink includes a plurality of apertures operationally configured to allow for air flow in and out of the space between the heat sink and the substrate.
In another aspect, the application provides a light assembly 5 incorporating an LED suitable for one or more of the following applications: high power flood lights, automotive (head lamps, turn signals), high lumen intensity signage, general outdoor and indoor illumination, and special spectrum lighting devices with complex phosphor and epi combination.
To better understand the novelty of the invention, reference is hereafter made to the accompanying drawings. It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. However, this inventive subject matter should not be construed as limited to the embodiments set forth herein. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention.
With reference to
With reference to
As
Without limiting the housing base 102 to any particular materials of construction, the housing base 102 is suitably constructed from materials 5 including, but not necessarily limited to those materials resistant to chipping, cracking, excessive bending and reshaping as a result of ozone, weathering, heat, moisture, other outside mechanical and chemical influences, physical impacts, and combinations thereof. In particular, the housing base 102 is suitably constructed from materials including but not necessarily limited to metals, polymeric materials, fiberglass, plexiglass, filled composite materials, and combinations thereof. In one exemplary embodiment, the housing base 102 may be constructed from one or more ultra-violet light stabilized plastic materials including, but not necessarily limited to polycarbonate, polyvinyl chloride (PVC), and combinations thereof. In another exemplary embodiment, the housing base 102 may be constructed from one or metals including, but not necessarily limited to stainless steel or aluminum. It is also contemplated that the housing base 102 may include any desired shape. For example, the housing base 102 may be circular, oval, or multi-sided as shown in
Suitably, the housing base 102 may include one or more apertures for receiving fastening means such as screws and the like for joining the power driver 104 to the housing base. The housing base 102 may also include apertures for joining the heat sink 105 thereto via one or more fastening means. In another embodiment, the housing base 102 may include an inner surface configuration effective for the power. driver 104 and/or the heat sink 105 to be snap fit to the housing base 102. In one embodiment, the housing base 102 and its sidewalls 103 (see
With reference to
A non-planar substrate 106 of the light assembly 100 may be provided in various forms. For example, the non-planar substrate 106 may include a spherical outer surface, or a convex outer surface as shown in the drawings. It is also contemplated that the non-planar substrate 106 may include other curved outer surfaces as desired. With reference to
With continued reference to
In addition, a suitable LED array 108 may be disposed across a metal substrate 106 having a reflective surface. In such embodiment, the metal substrate may include any reflective metal as desired. In one particular embodiment, the metal substrate may be constructed from aluminum including a reflective surface of bare or polished aluminum. Alternatively, the reflective surface may be formed by silver plating on the substrate 106. Therefore, it is contemplated that the surface of substrate 106 may be utilized as a reflective surface depending on the type of light source(s) being applied to the substrate 106 surface.
Suitably, the LED array 108 is in electrical communication with the power driver 104, which is operationally configured to power the array 108. A suitable power driver 104 includes, but is not necessarily limited to a constant current source LED driver (Input 85-227V) as is understood by persons of ordinary skill in the art. In a suitable embodiment, the power driver 104, heat sink 105, and LED array 108 lie in electrical communication by passing electrical pins 420 (having insulated sleeves disposed thereon) of the power driver 104 through apertures 111 in the heat sink 105, and making an electrical connection to the LEDs of LED array 108 in a manner known in the art. Although the LED array 108 may be powered as desired, when applied to a substrate 106 having a convex outer surface, wiring (not shown) is suitably run from the power driver 104 through an aperture at the apex of the substrate 106 to connect to the LED array 108.
As shown in
As stated above, since the LEDs have a mounting surface that is separate from the electrical path, the LEDs can be mounted directly onto the surface of the substrate 106. In doing so, an efficient thermal path is formed allowing heat to pass from the array of LEDs 108 to the substrate 106. It should also be noted that there is no limit on the number of LEDs that may be used and in fact, as the number of LEDs increases the optical gain increases. In one embodiment, a particular LED pattern using a predetermined number of LED may define the array 108. Ultimately, the maximum number of LEDs is determined by the surface area of the substrate 106 and the size of LEDs being used.
As desired, the LED array 108 is suitably mounted on the substrate 106 with a pre-determined spacing between adjacent LED. In one simplified example, the LED array 108 may be mounted to the substrate 106 in a manner to include a pattern and spacing as illustrated in
With reference to
As stated above, the lense 110 may be operationally configured to protect the LED array 108 of the assembly 100 and enhance light output of the assembly 100. Like the housing base 102, the lense 110 is suitably constructed from materials including, but not necessarily limited to those materials resistant to chipping, cracking, excessive bending and reshaping as a result of ozone, weathering, heat, moisture, other outside mechanical and chemical influences, physical impacts, and combinations thereof.
In one regard, the lense 110 may be provided for purely decorative or aesthetic purposes. Thus, the shape and color of the lense 110 may be altered as desired. In addition, the lense 110 may be constructed of one or more materials and include optical properties effective to enhance the light output of the light assembly 100. The lense 110 may further include UV light resistant materials. Suitable lense 110 materials include, but are not necessarily limited to glass, plastics including but not necessarily limited to acrylics, polycarbonates, and other synthetic polymers. In one embodiment, the lense 110 may be transparent or translucent. In another embodiment, the lense 110 may include a filter or include one or more colors effective for filtering light as desired.
The invention will be better understood with reference to the following non-limiting example, which is illustrative only and not intended to limit the present invention to a particular embodiment.
In a first non-limiting example, a light assembly 100 as depicted in
In a second non-limiting example, a light assembly 100 as depicted in
Persons of ordinary skill in the art will recognize that many modifications may be made to the present application without departing from the spirit and scope of the application. The embodiment(s) described herein are meant to be illustrative only and should not be taken as limiting the invention, which is further discussed in the paragraphs below.
A light assembly comprising: an outer housing; a power source; a heat sink disposed within the outer housing; and a non-planar substrate joined to the heat sink and operationally configured to accommodate one or more LED thereon.
The light assembly of the previous paragraph wherein the outer housing includes a base and a lense operationally configured to seal the power source, heat sink, substrate and accompanying LED array there between.
A light assembly comprising: a base including a heat sink and a power source; and a substrate having a non-planar surface attached to the heat sink, the shape of the substrate providing a space between the substrate and heat sink; wherein the substrate is operationally configured to receive one or more LED thereon; and wherein heat generated by the one or more LED is transferred away from the substrate toward the heat sink via said space there between.
The light assembly of the previous paragraph wherein the substrate includes a convex outer surface for receiving LED thereon.
A light assembly for illuminating light via an array of LED, the assembly comprising: a non-planar substrate, whereby the array of LED are mounted to the outer surface of the substrate in a manner effective whereby light emitted from each LED is directed along a non-parallel relationship in relation to light being emitted from the remaining LED of the array.
A light assembly for illuminating light via an array of LED, the assembly comprising: a non-planar substrate, whereby the array of LED are mounted to the outer surface of the substrate in a manner effective whereby light emitted from each individual LED is directed along a directional path substantially perpendicular to the plane of the tangent line located at the point of attachment of each LED to the non-planar substrate.
A method of increasing light spread as emitted from a light source comprised of a plurality of LED, the method comprising: providing a light assembly having (1) an outer housing; (2) a power source; (3) a heat sink disposed within the outer housing; and (4) a non-planar substrate joined to the heat sink and operationally configured to accommodate one or more LED thereon. A method of dissipating heat from a light source comprised of a plurality of LED, the method comprising: providing a light assembly having (1) an outer housing; (2) a power source; (3) a heat sink disposed within the outer housing, the heat sink having one or more apertures there through; and (4) a nonplanar substrate joined to the heat sink and operationally configured to accommodate one or more LED thereon.
This application claims the priority of U.S. Prov. Pat. App. Ser. No. 61/471,648 (filed Apr. 4, 2011).
Number | Date | Country | |
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61471648 | Apr 2011 | US |