LED bent panel light assembly

A light assembly includes an optically-transmissive panel bent so as to span more than 180° about a central axis. The optically-transmissive panel has top and bottom edge surfaces. An array of LEDs is disposed adjacent at least one of the top and bottom edge surfaces. The optically-transmissive panel is operative to produce a uniform distribution of light received from the array of LEDs. Circuitry is arranged to electrically connect the array of LEDs with a power source.

FIELD OF THE INVENTION

The present invention relates generally to lighting assemblies, and more particularly to an LED bent panel light assembly.

BACKGROUND OF THE INVENTION

For years, lighting systems, such as ceiling mounted lighting fixtures or luminaires, have made use of fluorescent lamps and/or incandescent lamps. In addition to the lamps, lighting systems typically include an assembly of components, such as ballasts and reflectors. Luminaires that incorporate fluorescent lamps are the most commonly used commercial light sources due to their relatively high efficiency, diffuse light distribution characteristics, and long operating life. Luminaires that incorporate light emitting diodes are emerging as an attractive alternative to fluorescent lamp luminaires, providing marked improvements in efficiency and operating life. LED flat panel lighting fixtures are now replacing fluorescent lights, such as in drop ceilings.

SUMMARY OF THE INVENTION

The present invention seeks to provide an improved lighting assembly, such as a LED bent panel light assembly, as is described more in detail hereinbelow.

There is thus provided in accordance with an embodiment of the present invention a light assembly including an optically-transmissive panel bent so as to span more than 180° about a central axis, the optically-transmissive panel having top and bottom edge surfaces, an array of LEDs disposed adjacent at least one of the top and bottom edge surfaces, the optically-transmissive panel operative to produce a uniform distribution of light received from the array of LEDs, and circuitry arranged to electrically connect the array of LEDs with a power source. The optically-transmissive panel may, for example, span 360° about the central axis. In one example, the optically-transmissive panel continuously curves about the central axis. In another example, the optically-transmissive panel is conically shaped and the array of LEDs is ring-shaped.

In accordance with an embodiment of the present invention a light modification layer is adjacent the optically-transmissive panel operative to modify light impinging thereon. For example, the light modification layer includes a reflective layer inwards of the optically-transmissive panel. In another example, a transparent glossy layer is between the light modification layer and the optically-transmissive panel.

The optically-transmissive panel may have different shapes, and for example, may include at least one flat portion.

A solar energy collecting portion may be mounted on the light assembly. The solar energy collecting portion may include at least one solar photovoltaic panel for collecting and converting incident solar energy to electricity to power the array of LEDs. One or more batteries may be provided that store electricity from the solar energy collecting portion, the batteries being electrically connected to the array of LEDs.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is now made toFIGS. 1-3, which illustrate a light assembly10, constructed and operative in accordance with a non-limiting embodiment of the present invention.

The light assembly10includes an optically-transmissive panel12bent so as to span more than 180° about a central axis14. The term “bent” encompasses any type of forming technique, such as but not limited to, bending, molding, folding, curving and others. Panel12is made of an optically-transmissive material, such as but not limited to, polycarbonate and the like. For example, without limitation, panel12may be made of a white milky semi-transparent material (e.g., polycarbonate or acrylate) with roughened outer surface, having a thickness of 1.6 mm.

The optically-transmissive panel12may, for example, span 360° about the central axis14. In the illustrated embodiment, panel12continuously curves about central axis14and is conically shaped. (FIGS. 6A-6Cillustrate other exemplary shapes, wherein panel12has one or more flat sides, as described below.)

It is noted that the prior art only uses flat sheet LED panels. This would require mounting the flat panels in frames to get a prismatic or polyhedral shape. In contrast, the present invention uses a one-piece, bent panel12, which provides advantages in terms of cost and assembly.

The optically-transmissive panel12has top and bottom edge surfaces16and18(FIG. 3), respectively. An array of LEDs20(FIGS. 1 and 5) is disposed adjacent at least one of the top and bottom edge surfaces16and18. In the illustrated embodiment, the LEDs20are mounted on top of top edge16and are ring-shaped. The array of LEDs20may be all around the perimeter or may span a portion of the perimeter of the top and/or bottom edge surfaces (such as an arc of 90° or 180° for a round perimeter, or just one or a few sides for a polygonal perimeter). The optically-transmissive panel12produces a uniform distribution of light received from LEDs20. Circuitry22(partially shown inFIG. 5and partially inFIG. 2) electrically connects the array of LEDs20with a power source24, such as one or more batteries24.

The LEDs20may be of any amount, size, mcd rating, and color (e.g., white, red, green, blue, yellow or other non-white colors, or a RGB (red, green, blue) changing LED, or any combination thereof). “White” is defined as the color that has no or little hue, due to the reflection of all or almost all incident light. “White” in the specification and claims encompasses bright white, warm white, “dirty” white, off-white, gray-white, snow white, hard-boiled-egg white and other shades of white. The colors of the lights may be programmed to change at predefined or random intervals, providing different lighting effects.

A solar energy collecting portion26(FIG. 1) may be mounted on light assembly10. Solar energy collecting portion26may include one or more solar photovoltaic panels for collecting and converting incident solar energy to electricity to power the array of LEDs20. In the illustrated embodiment, without limitation, the solar photovoltaic panel26is a disc of 300 mm diameter. Batteries24store electricity from the solar energy collecting portion26.

The LEDs20and batteries24may advantageously be low voltage, such as but not limited to, 3-4 V (e.g., batteries24may be lithium phosphate batteries). In this manner, the invention advantageously uses low power in a solar outdoor application, in contrast with prior art outdoor solar systems that use 12 V LEDs and higher voltage batteries with more complicated circuitry.

It is noted that in alternative embodiments, instead of solar power, the LEDs may be powered by AC or DC power from mains or other sources, with appropriate adaptors, inverters, rectifiers, converters, etc., as needed.

In accordance with an embodiment of the present invention a light modification layer28(FIG. 4) is adjacent optically-transmissive panel12and modifies light impinging thereon. For example, the light modification layer28includes a reflective layer inwards of the optically-transmissive panel12. For example, layer28may be a white material (plastic, such as polycarbonate, or metal, such as aluminum) with a glossy, reflective outer surface, having a thickness of 3.0 mm. In another example (seen inFIG. 4), a transparent glossy layer30is between the light modification layer28and the optically-transmissive panel12. For example, layer30may be a transparent glossy material (e.g., plastic), with a laser-formed pattern of points on its inside surface, having a thickness of 3.0 mm.

Accordingly, in order to create strong, homogeneous peripheral lighting, the LED bent panel light assembly may use three surfaces. An inner surface (light modification layer28) can be made of a dense mesh or reflective surface to receive the light rays from the LEDs. A middle transparent surface (layer30) increases the light intensity. An outside surface (optically-transmissive panel12) can be made of translucent or milky material for uniform distribution of the light.

In the illustrated embodiment, without limitation, the layers28and30are connected to panel at four bayonet connection points32. The array of LEDs20are mounted on a substrate34(FIG. 5), and this substrate34and the solar photovoltaic panel26are firmly mounted over (such as by snap connection) the bayonet connection points32. The substrate34may be made of a heat conducting material (e.g., aluminum) to dissipate heat from the LEDs20.

The layers28and30may be alternatively formed from films deposited on panel28. The panel12may also include a brightness enhancement film disposed thereon, which collimates light to improve the overall light output from panel12.

As mentioned above,FIGS. 6A-6Cillustrate other exemplary shapes, wherein panel12has one or more flat sides. InFIG. 6A, panel12has a square or rectangular shape with sloping sides and round edges between the sides. InFIG. 6B, panel12has a hexagonal shape with sloping sides and prismatic edges between the sides. InFIG. 6C, panel12has a square or rectangular shape with sloping sides and prismatic edges between the sides. The solar energy collecting portion26has four solar collecting panels which are mounted on top of the light assembly.FIGS. 6D-6Eillustrate the same panel ofFIG. 6Cwithout the solar energy collecting portion.

In general, it should be noted that the edges between adjacent flat sides may be, prismatic or curved or close to sharp with a very small radius of curvature, depending on the manufacturing technique to form the panel and its material. The invention is not limited to the number of sides, such as 3-10 or more, and may have shapes such as square, round, elliptic and many more.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.