Lighting fixture

0001This invention was made with government support under Contract Number DE_EE0006260 awarded by the United States Department of Energy. The government has certain rights in the invention.

TECHNICAL FIELD

0002Embodiments of the technology relate generally to lighting fixtures and more specifically to an outdoor luminaire, such as a streetlight, that comprises light emitting diodes and associated circuitry disposed against a metallic substrate.

BACKGROUND

0003For illumination applications, light emitting diodes (LEDs) offer substantial potential benefit associated with their energy efficiency, light quality, and compact size. However, to realize the full potential of the potential benefits offered by light emitting diodes, new technologies are needed. For instance, relative to incandescent lights, light emitting diodes typically have different thermal properties, different electrical characteristics, different manufacturing requirements, and different mounting constraints.

0004Accordingly, there are needs in the art for technology to manage heat produced by one or more light emitting diodes. Additional needs exist for lighting fixture configurations that facilitate cost-effective manufacturing. Need further exist for light emitting diode mounting technologies. Need also exists for lighting fixture configurations that facilitate cost-effective manufacturing and for improved technology for powering light emitting diodes. A capability addressing one or more such needs, or some other related deficiency in the art, would support improved illumination systems and more widespread utilization of light emitting diodes in lighting applications. Attention is drawn to <patcit id="pcit0001" dnum="US2011141728A1"><text>US 2011 141 728 A1</text></patcit>, which shows a lens frame for mounting and cooling LEDs. The lens frame may be continuous and attachable to a luminaire having a luminaire housing with an opening. The lens frame may extend across and close the opening of the luminaire housing. The lens frame may include a recessed support surface, a lens attachment area positioned outward from and peripherally of the support surface, and heat dissipating structure located peripherally of the support surface. A plurality of LEDs may be coupled to the support surface of the lens frame exteriorly of the luminaire housing and a lens may be coupled to the lens retaining area of the lens frame. Further, <patcit id="pcit0002" dnum="US2013155673A1"><text>US 2013 155 673 A1</text></patcit> relates to a street light having a lamp head including a housing and a plurality of LED light modules disposed within the housing. The LED light modules are separate and independent from each other and each include a cover having a plurality of openings. Each LED is aligned with and disposed within a respective one of the openings.

SUMMARY

0005In accordance with the present invention, a lighting fixture as in claim 1 is provided. Further embodiments are inter alia disclosed in the dependent claims.

0006Various aspects of the present technology may be more clearly understood and appreciated from a review of the following text and by reference to the associated drawings and the claims that follow. Other aspects, systems, methods, features, advantages, and objects of the present technology will become apparent to one with skill in the art upon examination of the following drawings and text. It is intended that all such aspects, systems, methods, features, advantages, and objects are to be included within this description and covered by this application and by the appended claims of the application.

BRIEF DESCRIPTION OF THE FIGURES

0007Reference will be made below to the accompanying drawings. <ul id="ul0001" list-style="none"><li><figref idref="f0001">Figures 1A</figref>, <figref idref="f0002">1B</figref>, and <figref idref="f0003">1C</figref> (collectively <figref idref="f0001 f0002 f0003">Figure 1</figref>) illustrate three views of a lighting fixture in accordance with some example embodiments of the present disclosure.</li><li><figref idref="f0004">Figures 2A</figref> and <figref idref="f0005">2B</figref> (collectively <figref idref="f0004 f0005">Figure 2</figref>) illustrate two exploded views of the lighting fixture illustrated in <figref idref="f0001 f0002 f0003">Figure 1</figref> in accordance with some example embodiments of the present disclosure.</li><li><figref idref="f0006">Figures 3A and 3B</figref> (collectively <figref idref="f0006">Figure 3</figref>) illustrate two views of an integrated cover and shield of the lighting fixture illustrated in <figref idref="f0001 f0002 f0003">Figures 1</figref> and <figref idref="f0004 f0005">2</figref> in accordance with some example embodiments of the present disclosure.</li><li><figref idref="f0007">Figures 4A and 4B</figref> (collectively <figref idref="f0007">Figure 4</figref>) illustrate two views of the lighting fixture illustrated in <figref idref="f0001 f0002 f0003">Figures 1</figref> and <figref idref="f0004 f0005">2</figref>, with the upper cover removed and installed, in accordance with some example embodiments of the present disclosure.</li><li><figref idref="f0008">Figures 5A and 5B</figref> (collectively <figref idref="f0008">Figure 5</figref>) illustrate perspective top and bottom views of the lighting fixture cover in accordance with some example embodiments of the present disclosure.</li><li><figref idref="f0009">Figures 6A, 6B</figref>, <figref idref="f0010">6C, and 6D</figref> (collectively <figref idref="f0009 f0010">Figure 6</figref>) illustrate an attachment system for mounting the lighting fixture to the pole in accordance with some example embodiments of the present disclosure.</li></ul>

0008The drawings illustrate only example embodiments and are therefore not to be considered limiting of the embodiments described, as other equally effective embodiments may fall within the scope of the invention as defined by the claims. The elements and features shown in the drawings are not necessarily drawn to scale, emphasis instead being placed upon clearly illustrating principles of the embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey certain principles. In the drawings, similar reference numerals among different figures designate like or corresponding, but not necessarily identical, elements.

DESCRIPTION OF EXAMPLE EMBODIMENTS

0009As will be discussed in further detail below, the lighting fixture according to claim 1 comprises an electrical circuit that is attached to a sheet of metal, with a layer of dielectric material positioned between the circuit and the sheet of metal. The layer of dielectric material can provide electrical insulation between the electrical circuit and the sheet of metal. In some example embodiments, the sheet of metal provides a ground plane for the electrical circuit. In some example embodiments, the sheet of metal provides electrical shielding for the electrical circuit. In some example embodiments, the sheet of metal may have a thickness in a range from approximately 0.0254 cm (0.01 inches) to approximately 0.635 cm (0.25 inches). Other embodiments may utilize other appropriate thicknesses that may be above or below that range, for example.

0010The electrical circuit can provide electricity for one or more light emitting diodes. The circuit comprises the light emitting diodes, so that the light emitting diodes are mounted adjacent the sheet of metal. An array of light emitting diodes is attached to the sheet of metal, and the layer of dielectric material electrically insulates the light emitting diodes from the sheet of metal.

0011Each light emitting diode has an associated optic that manages emitted light. An array of such optics is mounted adjacent an array of light emitting diodes. The array may be two dimensional in some embodiments, for example. In some example embodiments, a sheet of pliable material, such as gasket material, is disposed between the array of optics and the layer of dielectric material to provide environmental protection, including to protect against moisture ingress.

0012Some representative embodiments will be further described hereinafter with example reference to the accompanying drawings that describe representative embodiments of the present technology. The technology may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the technology to those appropriately skilled in the art.

0013Turning now to <figref idref="f0001">Figures 1A</figref>, <figref idref="f0002">1B</figref>, and <figref idref="f0003">1C</figref>, these figures illustrate three views of an example lighting fixture 100 in accordance with some embodiments of the present disclosure. <figref idref="f0001">Figure 1A</figref> illustrates a perspective view of the underside of the lighting fixture 100. <figref idref="f0002">Figure 1B</figref> illustrates a perspective view of the top of the lighting fixture 100. And, <figref idref="f0003">Figure 1C</figref> illustrates a side view in perspective.

0014In the illustrated example, the lighting fixture 100 comprises an outdoor luminaire, specifically a pole-mounted streetlight. A clamp 120 attaches the lighting fixture 100 to the end of a pole 105. The clamp 120 comprises a bracket 121 that provides vibration support. The lighting fixture 100 comprises an integral shroud 107 adjacent the clamp 120 that covers the end of the pole 105.

0015As illustrated, the lighting fixture 100 comprises an array of light emitting diodes 126 for emitting light and a corresponding array of optics 125 for directing the emitted light to provide a desirable illumination pattern. In other embodiments, a single light emitting diode may be utilized.

0016A light shield 150 extends about the periphery of the array of optics 125. The light shield 150 prevents the emitted light from traveling skyward, thus suppressing light pollution. In other words, the light shield 150 occludes rays of light oriented in an unintended direction, for example skyward. In some embodiments, the light shield 150 is a unitary element. In other embodiments, the light shield 150 comprises multiple components.

0017A cover 110 provides environmental protection for the lighting fixture 100. The cover 110 further facilities thermal transfer of heat generated in connection with producing light from electricity. In some embodiments, the cover 110 is a unitary element. In other embodiments, the cover 110 comprises multiple components.

0018A photocontroller 115 is mounted on top of the cover 110. The photocontroller 115 senses ambient light level, turns the lighting fixture 100 on when the ambient light level is low, for example at dusk, and turns the lighting fixture 100 off in daylight conditions. In some embodiments, the photocontroller 115 can comprise multiple sensors, including an occupancy sensor or personnel sensor, for example. In some embodiments, the photocontroller 115 can be replaced by one or more other types of sensors, for example an occupancy sensor or personnel sensor. In some embodiments, such an occupancy sensor may be mounted on the light emitting side of the lighting fixture, for example.

0019The illustrated lighting fixture 100 further comprises a cover 130 on the fixture's light-emitting underside that provides an environmentally protected space for electrical elements. In some embodiments, the cover 130 is a unitary element. In other embodiments, the cover 130 comprises multiple components. In the illustrated embodiment, an opening 131 (visible in <figref idref="f0006">Figures 3A and 3B</figref>) that provides passage for lead wires. In an example embodiment, the opening has an associated grommet that helps avoid abrasion of the lead wires.

0020In some embodiments, one or more sensors can be mounted to the cover 130, for example an occupancy or personnel sensor that detects presence of one or more people utilizing passive infrared sensing or other appropriate technology. In various embodiments, the cover 130 can comprise one or more holes, apertures, or windows for mounting such sensors, surge protection, and/or other appropriate devices. For example, such holes can be located in an area 132 of the cover 130 near the shroud 107.

0021In various embodiments, the cover 130 can have various electronic components mounted to the inside of the cover 130 or to the outside of the cover 130. In some example embodiments, the cover 130 has a recessed shape. In some example embodiments, the cover 130 has a substantially flat shape.

0022Turning now to <figref idref="f0004">Figures 2A</figref> and <figref idref="f0005">2B</figref>, these figures illustrate two exploded views of the example lighting fixture 100 initially illustrated in <figref idref="f0001 f0002 f0003">Figure 1</figref> and discussed above in accordance with some embodiments of the present disclosure. <figref idref="f0004">Figure 2A</figref> illustrates a side perspective view of the exploded assembly, while <figref idref="f0005">Figure 2B</figref> illustrates a bottom perspective view of the exploded assembly.

0023In the illustrated example embodiment, a gasket 135 is located between the cover 110 and the sheet of metal 140. The gasket 135 provides environmental protection, including against moisture ingress.

0024In some example embodiments, the sheet of metal 140 is flat or substantially flat. As discussed above, circuitry, including light emitting diodes 126, is mounted to the lower side of the sheet of metal 140. In some example embodiments, the sheet of metal 140 can comprise one or more recesses. In some example embodiments, the sheet of metal 140 is contoured on one or both sides, for example.

0025The photocontroller 115 is mounted at the upper surface of the cover 110 as discussed above. A gasket 103 is located between the cover 110 and the photocontroller 115 and seals around the periphery of the photocontroller 115. The gasket 103 can prevent ingress of water or dust.

0026A sheet of gasket material 145 is located between the array of optics 125 and the light shield 150, which functions as a frame. The sheet of gasket material 145 seals the light emitting diodes 126 and circuitry against moisture ingress.

0027The light emitting diode circuit comprises circuitry printed on a layer of insulating material that has been coated on the sheet of metal 140. The circuitry may include light emitting diodes 126, electrical traces, and/or one or more light emitting diode drivers 109. At least the electrical traces are printed on the layer of insulating material that has been coated on the sheet of metal 140.

0028The light shield 150 extends around the array of optics 125 and light emitting diodes 126 as discussed above. The cover 130 is located on the pole side of the array of optics 125 and can provide light shielding as well as an enclosed space.

0029Turning now to <figref idref="f0006">Figures 3A and 3B</figref>, these figures illustrate two views of the integrated cover 130 and shield 150 of the example lighting fixture 100 illustrated in

0030<figref idref="f0001 f0002 f0003">Figures 1</figref> and <figref idref="f0004 f0005">2</figref> and discussed above in accordance with some embodiments of the present disclosure. <figref idref="f0006">Figure 3A</figref> illustrates a perspective view of the side of the integrated cover 130 and light shield 150 that faces outward when mounted on the lighting fixture 100 as illustrated in <figref idref="f0001 f0002 f0003">Figures 1</figref> and <figref idref="f0004 f0005">2</figref>. <figref idref="f0006">Figure 3B</figref> illustrates a perspective view of the opposite side of the integrated cover 130 and light shield 150, which faces inward when mounted on the lighting fixture 100 as illustrated in <figref idref="f0001 f0002 f0003">Figures 1</figref> and <figref idref="f0004 f0005">2</figref>.

0031The inward facing side of the cover 130 is recessed to provide space for housing electrical components, including wiring. As shown in <figref idref="f0004">Figure 2A</figref> and <figref idref="f0005">2B</figref>, the gasket 145 extends around the periphery of the integrated cover 130 and light shield 150 to seal the space environmentally.

0032The cover 130 provides an enclosed space that is under an opening 131 (illustrated in <figref idref="f0004">Figures 2A</figref> and <figref idref="f0005">2B</figref>) in the sheet of metal 140, and that opening 131 is aligned with the photocontroller 115 and the associated opening 132 in the cover 110. Accordingly, wiring feeds between the enclosed space of the cover 130 and the photocontroller 115. However in some embodiments, the cover 110 does not have such an opening.

0033Turning now to <figref idref="f0007">Figures 4A and 4B</figref>, these figures illustrate two views of the example lighting fixture 100 illustrated in <figref idref="f0001 f0002 f0003">Figures 1</figref> and <figref idref="f0004 f0005">2</figref> and discussed above in accordance with some embodiments of the present disclosure. <figref idref="f0007">Figure 4A</figref> illustrates the lighting fixture 100 with the cover 110 removed to expose the sheet of metal 140. <figref idref="f0007">Figure 4B</figref> illustrates the lighting fixture 100 with the cover 110 attached.

0034As illustrated in <figref idref="f0007">Figure 4B</figref>, the cover 110 is slanted and contoured to prevent rainwater from accumulating on the top of the lighting fixture 100. In other words, the cover is formed to shed water, such as rainwater.

0035Turning now to <figref idref="f0008">Figures 5A and 5B</figref>, these figures respectively illustrate perspective top and bottom views of the cover 110 in accordance with some example embodiments of the present disclosure. As illustrated in <figref idref="f0004">Figures 2A</figref> and <figref idref="f0005">2B</figref>, a gasket 135 can extend around the periphery of the cover 110 for environmental sealing. The cover 110 can comprise a gasket groove in which the gasket 110 is seated, for example.

0036In some embodiments, the cover 110 can comprise metal inserts for holding other components or for mounting. For example, the cover 110 can comprise fastening elements molded or otherwise inserted.

0037The views of <figref idref="f0008">Figure 5</figref> further illustrate the water-shedding contours that the cover 110 provides the lighting fixture 100 as discussed above. Additionally, <figref idref="f0008">Figure 5</figref> shows a representative form for the portion of the cover 110 to which the photocontroller 115 is mounted as dis-cussed above.

0038Turning now to <figref idref="f0009">Figures 6A, 6B</figref>, <figref idref="f0010">6C, and 6D</figref>, these figures illustrate an example attachment system for mounting the lighting fixture 100 to the pole 105. <figref idref="f0009">Figure 6A</figref> illustrates a perspective view of the clamp 120 with the bracket 121 included. <figref idref="f0009">Figure 6B</figref> illustrates a perspective view of the bracket 121. <figref idref="f0010">Figure 6C</figref> illustrates another perspective view of the clamp 120 and the associated bracket 121. <figref idref="f0010">Figure 6D</figref> illustrates another perspective view of the clamp 120 and the associated bracket 121.

0039The clamp 120 comprises bolts 191 that apply clamping force around the pole 105 in order to set and maintain the position of the lighting fixture 100 at the pole end. The bracket 121 is positioned on the upper side of the pole 105 and stabilizes the lighting fixture 100, including for vibration support. The collar 192 of the clamp 120 can accommodate poles 105 of varying diameters, as the bottom band that spans across one side of the pole is deformable relative to the upper member.

0040In some example embodiments, the clamp 120 comprises a lower pole mounting plate with stamped-in ramps that allow the lighting fixture 100 to be mounted at multiple angles on the pole 105. See for example <figref idref="f0009">Figures 6A and 6B</figref>.

0041Many modifications and other embodiments of the disclosures set forth herein will come to mind to one skilled in the art to which these disclosures pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of this application. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.