# Patent

## Title
Luminaire with long chains of lower power LEDs and multiple on-board LED drivers

## Abstract

A luminaire may include an input connection that receives AC line voltage, one or more chains of LEDs, and one or more drivers for driving each chain of LEDs, all within a housing, which may be in the form of a canopy. Each chain of LEDs may contain at least 36 LEDs connected in series. Each LED may have a power rating of no more than 1 watt and may be oriented to direct light outside of the housing when illuminated. Each driver may receive power that is extracted from AC line voltage connected to the input connection and provide one or more outputs that drive at least one of the chains of LEDs.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of U.S. patent application Ser. No. 13/828,446, entitled “Luminaires and Luminaire Mounting Structures,” filed Mar. 13, 2014. The entire content of this application is incorporated herein by reference.


BACKGROUND
1. Technical Field
This disclosure relates to luminaires, including outdoor lighting canopies that are driven by AC line voltage and include multiple LEDs.
2. Description of Related Art
Outdoor canopy lighting may utilize multiple LEDs mounted within a housing to provide needed lighting. These LEDs may need a driver to generate the regulated current that is needed to drive the LEDs.
A single large driver is usually mounted outside of the luminaire housing to drive the LEDs. This has been done because of concern over the effect of noise generated by the LEDs within the housing on the operation of the driver, because of the absence of strong surge protection inside of the luminaire housing to protect the driver from surges in line voltage, and to make it easy to replace components in the driver that sometimes fail, such as electrolytic capacitors. However, positioning the driver outside of the canopy housing may require a separate housing to house the driver. This may add to costs and require added space for the separate housing
Drivers have also been designed to drive a chain of series-connected LEDs in sub-chain steps that correspond to the amplitude of the line voltage. Typically, the chain and each of its sub-steps consist of a small number of high power LEDs to minimize costs and maximize durability. However, high power LEDs can be less efficient and using a small number can result in spotted lighting patterns.
SUMMARY
A luminaire may include an input connection that receives AC line voltage, one or more chains of LEDs, and one or more drivers for driving each chain of LEDs, all within a housing. Each chain of LEDs may contain at least 36 LEDs connected in series. Each LED may have a power rating of no more than 1 watt and may be oriented to direct light outside of the housing when illuminated. Each driver may receive power that is extracted from AC line voltage connected to the input connection and provide one or more outputs that drive at least one of the chains of LEDs.
Each chain of LEDs may include multiple sub-chains of LEDs connected in series, each sub-chain containing multiple LEDs in series. Each of the LED drivers may provide a separate output that drives at least one of the chains of LEDs at each of the junctions between each of its sub-chains in a stepped sequence that is a function of the level of voltage of the power that is received by LED driver.
At least one sub-chain within each chain may include at least 12 LEDs.
No sub-chain within each chain may include less than 6 LEDs.
The outputs of at least two of the LED drivers may be connected in parallel.
The outputs of at least one of the LED drivers may be connected to one of the chains of LEDs and the outputs of at least one other of the LED drivers may be connected to another of the chains of LEDs.
The input connection, the chains of LEDs, and the LED drivers may all be on a single printed circuit board.
Each chain of LEDs may have at least 48 LEDs.
The power rating of each LED may be no more than 0.6 watts.
The housing may form a canopy light.
These, as well as other components, steps, features, objects, benefits, and advantages, will now become clear from a review of the following detailed description of illustrative embodiments, the accompanying drawings, and the claims.



BRIEF DESCRIPTION OF DRAWINGS
The drawings are of illustrative embodiments. They do not illustrate all embodiments. Other embodiments may be used in addition or instead. Details that may be apparent or unnecessary may be omitted to save space or for more effective illustration. Some embodiments may be practiced with additional components or steps and/or without all of the components or steps that are illustrated. When the same numeral appears in different drawings, it refers to the same or like components or steps.
FIG. 1A is a bottom-side perspective view of a luminaire in accordance with the present disclosure;
FIG. 1B is a top-side perspective view of the luminaire depicted in FIG. 1A with driver box and stem;
FIG. 1C is an exploded view of the luminaire depicted in FIG. 1A with driver box, stem and gasket;
FIG. 2A is a bottom-side perspective view of a housing of the luminaire depicted in FIG. 1A;
FIG. 2B is a top-side perspective view of a housing of the luminaire depicted in FIG. 1A with the lens frame shown for context;
FIG. 3A is a top-side perspective view of a lens frame of the luminaire depicted in FIG. 1A;
FIG. 3B is an outtake of a portion of the lens frame of FIG. 3A, with a gasket and adhesive sealant not depicted in FIG. 3A;
FIG. 4A is a cross-section of a portion of the luminaire depicted in FIG. 1A;
FIG. 4B is a different cross-section of a portion of the luminaire depicted in FIG. 1A;
FIG. 4C is yet another different cross-section of a portion of the luminaire depicted in FIG. 1A;
FIG. 4D is a cross-section of a portion of the luminaire depicted in FIG. 1A showing a greater width of the luminaire than FIGS. 4A-C;
FIG. 4E is a cross-section of the housing stem of the luminaire depicted in FIG. 1A populated with wiring and breathing tube;
FIG. 5A is a bottom side view of the driver box and driver box stem depicted in FIG. 1B;
FIG. 5B is an exploded view of the luminaire depicted in FIG. 1A and the driver box and gasket depicted in FIG. 1C in the context of installation to a structure;
FIG. 6 is a bottom side view of the printed circuit board of the luminaire depicted in FIG. 1A;
FIG. 7A is a bottom-side perspective view of the luminaire depicted in FIG. 1A mounted in a mounting structure;
FIG. 7B is a perspective cross-sectional view of the luminaire and mounting structure depicted in FIG. 7A;
FIG. 7C is a top side view of the luminaire and portions of the mounting structure depicted in FIG. 7A;
FIG. 7D is a cross-sectional view of portions of the luminaire and mounting structure depicted in FIG. 7A;
FIG. 7E is a perspective view of a locking wing of the mounting structure depicted in FIG. 7A; and
FIGS. 7F and 7G are perspective views of optional mounting structure extensions of the mounting structure depicted in FIG. 7A.
FIG. 8 illustrates an example of a circuit that includes a driver and a long chain of low power LEDs that may be driven by the driver, all of which may be on a single circuit board within an outdoor canopy light.
FIG. 9 illustrates an example of a circuit that includes multiple drivers and a long chain of low power LEDs that may be driven by the multiple drivers while their outputs are connected in parallel, all of which may be on a single circuit board all within an outdoor canopy light.
FIG. 10 illustrates an example of a block diagram of an outdoor canopy light that may use a single D.C. power supply to supply power to one or more drivers that each drive one or more long chains of low power LEDs, each LED chain and associated driver(s) being in a different quadrant of an outdoor canopy light.
FIG. 11 illustrates an example of one quadrant of a long chain of low power LEDs on a single circuit board.
FIG. 12 illustrates an example of a single circuit board that may be placed within an outdoor canopy light that includes four quadrants, each with a long chain of low powered LEDs and an associated power supply and drivers.



DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Illustrative embodiments are now described. Other embodiments may be used in addition or instead. Details that may be apparent or unnecessary may be omitted to save space or for a more effective presentation. Some embodiments may be practiced with additional components or steps and/or without all of the components or steps that are described.
While the preferred embodiment uses light emitting diodes (“LEDs”) as light sources, other light sources may be used in addition to LEDs or instead of LEDs within the scope of the present disclosure. By way of example only, other light sources such as plasma light sources may be used. Further, the term “LEDs” is intended to refer to all types of light emitting diodes including organic light emitting diodes or “OLEDs”.
While the luminaire depicted in the Figs. is generally applicable to any application that would benefit from indoor or outdoor area lighting, it is well-suited, in one example, for application to canopies and the like such as those used at petroleum refill stations. In other applications, luminaires and mounting structures disclosed herein are applicable to soffits or ceilings.
FIGS. 1A and 1B depict bottom-side and top-side perspective views of a luminaire 100, in accordance with the present disclosure, which is a low-profile luminaire capable of providing proper light distribution and having a minimum number of parts. The luminaire 100 comprises a housing 102, a circuit board 104 populated with light sources 106 such as LEDs, a plurality of screws 108, a lens 110, a gasket 112 and a lens frame 114. The circuit board 104 can be any known circuit board for properly arranging the light sources 106 and, in one embodiment, can be a printed circuit board (“PCB”). For the sake of simplicity, circuit board 104 will be referred to herein as a PCB, but it will be understood that any type of circuit board is suffice.
The overall shape of the luminaire 100 is depicted as substantially square with rounded corners, but other shapes are contemplated as operating within the scope of this disclosure. By way of example only, rectangular, circular and triangular are all contemplated. Because the overall shape of the luminaire 100 is dictated in the depicted embodiment by the shape of the housing 102 and the lens frame 114, the shape of the housing 102 and lens frame 114 are likewise contemplated as have these exemplary shapes or others.
The housing 102 comprises a plate 116, a perimeter 118 and a wall 120 between the face 116 and the perimeter 118. The perimeter 118 extends about the perimeter of the housing and thus takes the shape of the housing, which in the depicted embodiment, is square with rounded corners, as discussed above. The perimeter 118 defines a front face 118a and a rear face 118b. The front face 118a of the perimeter 118 extends from an inner edge 118c to an outer edge 118d which defines the outermost perimeter of the housing 102. The perimeter inner edge 118c defines the downward most facing portion of the housing 102. The front face 118a of the perimeter 118 extends from the perimeter inner edge 118c to the perimeter outer edge 118d forming a curvilinear front face 118a. In the depicted embodiment, the curvilinear front face 118a initially extends outward form the inner edge 118c in straight horizontal manner, and then curves upward with an ever-increasing radius of curvature to the perimeter outer edge 118d. Other curvilinear shapes are contemplated as falling within this disclosure. By way of example only, the front face could extend horizontally to a 90° edge, which then extends upward to the outer edge.
References herein to upward and downward orientation are with reference to the depicted embodiments in which the luminaire 100 is mounted to the underside of a flat structure (such as a ceiling or a canopy) and are for purposes of conveying a description of the elements of the disclosure, but are in no way intended to be limiting. In application, upward can be reoriented downward and downward can be reoriented upward.
The housing perimeter 118 preferably defines one or more locator grooves 122 extending from the perimeter front face upward into the perimeter with a locator groove wall 122a to a locator groove base 122b that is flat in the depicted embodiments, but can vary, extending horizontally. The locators grooves 122 receive locator bosses 140 on the lens frame 114 to assist in properly locating the lens frame 114 on the housing 102 and, separately, to accommodate a boss from the lens frame 114 which can receive a mounting screw 134 from the groove base 122b, which will remain hidden from sight to persons viewing the bottom of the luminaire 100, in the depicted embodiment. FIG. 4B depicts a cross-section of a portion of the luminaire 100 through a locator groove 122, a corresponding locator boss 140 and mounting screw 134.
In the depicted embodiment, the luminaire 100 defines two locator grooves 122 on each of the four sides defining the square shape of the luminaire 100. Greater or fewer locator grooves 122 are contemplated. For example, if the locator grooves 122 are used purely for locating the lens frame 114 on the housing 102, then one, or two would suffice. Alternatively, an embodiment of the luminaire 100 is contemplated with no locator grooves 122. If, however, the locator grooves 122 are used to accommodate a boss to facilitate mounting the housing 102 to the lens frame 114 by screw, or the like, then the number and location of the locator grooves 112 will be dictated by the size and weight of the lens frame 114 in order to properly secure the lens frame 114 to the housing 102 with sufficient sealing there between, if desired, as discussed below.
The housing plate 116 extends across the housing to fill in the area surrounded by the housing perimeter 118. The housing wall 120 extends downward from the housing plate 116 just inward of the housing perimeter 118 to a distal end 120a and about the entire housing plate 116 as depicted in FIG. 2A. The housing wall 120 does not extend as far down as the inner edge of the perimeter 118. Rather, the housing wall 120 extends downward far enough to engage the gasket 112 located in the lens frame 114 as shown in FIGS. 4A-4D and discussed below. In this manner, the wall 120 deforms the gasket 112 forming a vapor and moisture barrier there between. Because the wall 120 and gasket 112 extend about the entire luminaire 100 just inward of the perimeter 118, a vapor and moisture barrier is formed between areas inward of the wall 120 (e.g. the PCB) and areas outward of the wall 120. This construction forms a barrier against vapor and moisture that might otherwise ingress between the housing 102 and lens frame 114. The housing wall 120 can take different forms as seen in FIGS. 4A-4D in order to minimize weight and material while still creating sufficient deformation of the gasket 112 to create desired vapor and moisture barrier.
The housing plate 116 has a front face 116a and a rear face 116b. The housing plate front face 116a is substantially flat, extending across and filling in the perimeter 118, with the exception of a plurality of mounting holes 124 defined therein and a spacer boss 126 surrounding and extending each mounting hole 124 out beyond the housing plate front face 116a. Each spacer boss 126 comprises a cylindrical wall extending downward from the housing plate front face 116a to a distal end 126a and configured so that an inner wall of the spacer boss 126 continues the inner wall of the corresponding mounting hole 124 so that the spacer boss 126 effectively extends the depth of the mounting hole 124 to a depth B. In the depicted embodiment, the spacer boss distal end 126a sits approximately even with a front face 104a of the PCB (as depicted in FIGS. 4A and 4D), thus acting to space the head of the screws 108 a distance approximately equal to the thickness of the PCB, shown as distance C in FIG. 4D, to the PCB front face 104a. In one exemplary embodiment, distance B can be 0.125 inches, where the distance C can be 0.047 inches. In another exemplary embodiment, height of the spacer bosses 126 is just short of the thickness of the PCB 104 so that the screws 108 not only hold the PCB 104 from falling off the housing 102, but also hold it steady, preventing rattle of the PCB 104 and creating a heat transfer connection between the PCB 104 and the housing 102 causing the housing 102 to act as a heat sink for the PCB 104 and the LEDs 106 mounted thereon. These objectives are enhanced when the screws 108 are constructed of a pliable material, as discussed below. The height of the spacer bosses 126 could be 0.002 inches shorter than the thickness of the PCB 104 in one embodiment. Other dimensions are contemplated to meet these objectives.
In an alternative embodiment, no spacer bosses 126 are employed. However, the spacer bosses 126 provide two advantages. First, the spacer bosses 126 reduce assembly time by allowing screws 108 to be driven into the mounting holes 124 without regard for when they reach the PCB 104. Without the spacer bosses 126, advancing the screws 108 would be conducted with concern about advancing them too far or with too much power, either of which might damage the PCB 104. The spacer bosses 126 obviate that concern by allowing the screws 108 to be advanced to the spacer boss distal end 126a as quickly and efficiently as possible. This ease of securing the screws 108 to the housing 102 without damaging the PCB 108 is further advanced by using screws 108 of a pliable material such as, by way of example only, nylon. Use of such pliable screws 108 will allow the screws 108 to be advanced without regard for exactly when advancement need stop. That is, over advancing the screws 108 will not “strip” the mounting holes 124 or damage the screws 108 to an extent such to prevent them from holding the PCB 104 to the housing 102. Instead, by using screws 108 of a pliable material, over advancing the screws will slightly deform the threads of the screws 108, but not so much as to prevent the pliable threads of the screws 108 from grasping the inside of the mounting holes 124.
Moreover, in the depicted embodiment, the inner wall of the mounting holes 124 is straight (i.e. is not threaded). This further limits production costs by removing the need to tap the mounting holes 124 or create a complicated mold having reliable threads in the mounting hole 124. Additionally, using straight mounting holes 124 actually allows shallower mounting holes 124 because the use of a typically tap to create the threads in a mounting hole requires a certain depth in order to facilitate the tapping. Using straight holes eliminates the need to be able to tap the mounting holes 124, thus allowing shorter mounting holes 124 than could otherwise be used. In one exemplary embodiment, the depth B of the mounting holes 124 is 0.125 inches. Furthermore, by using the spacer bosses 126 to extend the wall of the mounting hole 124 out to the face of the PCB 104, the depth of the mounting hole 124 is moved into the luminaire 100, reducing the distance that the mounting hole 124 need extend toward the housing plate rear face 116b, thus allowing a thinner overall luminaire 100. Moreover, using pliable screws 108 in straight mounting holes 124 further reduces, or eliminates, the likelihood of damaging the screws 108 by over advancement.
The second advantage provided by the spacer bosses 126 is their inherent ability to reduce tolerances in the stack of elements (housing 102, PCB 104, screws 108, lens 110 and lens frame 114) contributing to the over all height of the luminaire 100, and thus its low-profile. As discussed in greater detail below, tight stack of these element contributes to the low-profile. The ability to advance the screws 108 against the spacer bosses 126 without exception so as to limit the tolerances necessary and contribute to an overall low profile. The additional cost of these spacer bosses is negligible in an embodiment where the housing is cast from a material (e.g. aluminum).
The housing plate rear face 116b is also substantially flat, with the exception of a matrix of interconnecting walls 128 extending from the rear face 116b a short distance off that face. This matrix 128 increases the overall rigidity of the plate 116 and thus the housing 102. The matrix 128 also provides additional surface area on the rear of the housing 102 to increase the ability of the housing to dissipate heat when any of the matrix 128 is exposed to ambient air. The matrix 128 also assists in providing surface contact with structure to which the housing is mounted when that structure has surface irregularities (i.e. is not flat). This surface contact can also be helpful in directing heat away from the luminaire 100 in installations such as a petroleum refill station canopy which is constructed of sheet metal and much of the sheet metal, except where contacted by the housing, is exposed to ambient air to facilitate transferring to the surrounding air, some of the heat generated by the light sources or utilities for powering the light sources.
The matrix 128 may optionally include bosses 130 at the bottom of the mounting holes 124. These bosses 130 provide additional thickness to account for molding irregularities.
In the depicted embodiment, the housing perimeter rear face 118b follows the curvature of the housing perimeter front face 118a for the most part. A cross-section of one embodiment is depicted in FIG. 4C. This embodiment keeps the perimeter thin and reduces material usage while the curvature provides structural rigidity. Other shapes and thicknesses are contemplated. The housing perimeter rear face 118b also includes the backside of the locator groove wall 122a and locator groove base 122b protruding therefrom.
As discussed above, one or more of the locator groove bases 122b define a screw aperture 132 to accommodate a screw 134 to extend through the housing 102 and into the lens frame 114 to secure the lens frame 114 to the housing 102. In the depicted embodiment, the screw 134 enters from the housing and extends into the lens frame 114 so as to not be visible from the front side of the luminaire 100. A cross-section of this embodiment is depicted in FIG. 4B. Other embodiments are contemplated.
In order to minimize the number of screws 134 necessary for assembly and minimize the corresponding assembly steps, one or more fins 136 may extend across the housing perimeter rear face 118b to fill in the back side of the housing perimeter 118 curvature and provide the housing perimeter 188 with added structural rigidity. In the depicted embodiment, each side of the square housing comprises a single such fin 136 between the two screws 134 and one such fin 136 at each rounded corner of the housing perimeter 118. A cross-section of this embodiment is depicted in FIG. 4A. Other embodiments are contemplated.
The lens frame 114 defines a front face 114a and a rear face 114b and comprises a lens frame perimeter 136 at the outermost perimeter of the lens frame 136 and a trough 138 defined by an inner trough wall 138a and outer trough wall 138b. The contour of rear face 114b of the lens frame perimeter 136 follows the contour of the housing perimeter front face 118a, extending to a distal end 136a that lies in approximately the same horizontal plane as the housing perimeter outer edge 118d. References herein to a “horizontal” plane are by way of describing relationships between elements and portions of elements in the disclosed luminaire 100 and the term “horizontal” is used because the luminaire 100 is described as being mounted to a ceiling or the like. Use of the term “horizontal” is not limiting on the luminaire 100 as it could be rotated to be mounted in any orientation. By extending the lens frame perimeter distal edge 136a to the housing perimeter outer edge 118d, the lens frame can cover the housing perimeter 118 from view to provide the luminaire 100 a simple and elegant aesthetic look as seen in FIG. 1A. One of more locator boss 140 extends rearward from the lens frame rear face 114b into the curvature defined by the lens frame perimeter 136. As described above, the locators grooves 122 of the housing 102 receive the locator bosses 140 to assist in properly locating the lens frame 114 on the housing 102 and, separately, to receive the mounting screw 134, which will remain hidden from sight to persons viewing the bottom of the luminaire 100, in the depicted embodiment. FIG. 4B depicts a cross-section of a portion of the luminaire 100 through a locator groove 122, a corresponding locator boss 140 and mounting screw 134. The lens frame 114 is oriented vertically at the distal edge 136 and then curves downward and inward with an ever increasing radius of curvature the farther it is from the distal edge 136 until it is oriented approximately horizontal where it is adjacent to the housing perimeter inner edge 118c. 
A base 138c of the lens frame trough 138 continues to extend inward from the lens frame perimeter 136 horizontally and seamlessly from the lens frame perimeter 136. Other embodiments are contemplated. The lens frame trough inner trough wall 138a then extends vertically to define the lens frame innermost perimeter which defines a lens frame aperture 142 through which light emitted by the light sources 106 passes to leave the luminaire 100.
Gasket 112 is located about the perimeter of the trough outer wall 138b (depicted in FIG. 3B and FIGS. 4A-4D, but not FIG. 3A), which holds the gasket 112 in place during assembly. When the housing 102 and lens frame 114 are brought into alignment with, and secured one to the other, the housing wall 120 contacts and deforms the gasket 112. In the deformed state, the gasket 112 forms a seal against ingress of vapor, moisture, water or dirt between the housing 102 and the lens frame 114. The gasket 112 extends around the entire perimeter of the outer trough wall 138b and the housing wall 120 extends around the entire housing 102 such that the seal formed between the housing wall 120 and the gasket 112 extends about the entire perimeter of the PCB 104 preventing ingress of vapor, moisture, water or dirt between the housing 102 and the lens frame 114 that could reach the PCB 104 or other portions of the luminaire 100 within that perimeter seal. In an alternative embodiment, a urethane sealant could be substituted for the gasket 112. For the sake of efficiency, this urethane adhesive could be the same urethane adhesive as used in the trough 138, as discussed below.
The trough inner wall 138a extends upward a distance A (FIG. 4D) from the trough base 138c to a distal end on which the lens 110 rests. The lens 110 is sized so as to rest on the trough inner wall 138a distal end and extend almost all of the way to the trough outer wall 138b, leaving at least sufficient space there between to ease assembly. The trough outer wall 138b extends upward from adjacent the lens frame perimeter 136 and upward beyond the lens 110. The trough inner wall 138a is therefore shorter than the trough outer wall 138b. An adhesive sealant 144 is deposited into the trough 138 during assembly in a bead having a height sufficient so that when the lens 110 is placed on top of the bead, the lens 110 will deform the bead of adhesive sealant 144 until the lens 110 contacts and rests on the tough inner wall 138a distal end. The height of the trough inner wall 138a is a height A, and is designed to prevent the lens 110 from squeezing all of the adhesive sealant 144 out from between the lens frame 114 and lens 110 by limiting the distance between the lens 110 and the trough base 138c to height A. In this manner, the deformed bead of adhesive sealant 144 will have sufficient height to provide adhesion between the lens 110 to the lens frame 114. In one exemplary embodiment, the height A is 0.094 inches when using a 0.225 inch diameter bead of a urethane adhesive (SikaTack®-Ultrafast, sold by Sika Corporation, in one embodiment). In this embodiment, it has been found that the bead compresses to approximately the height A and approximately 0.425 inches, providing sufficient surface area to adhere to the lens 110. Other heights A, bead diameters and adhesive sealants are contemplated.
As depicted in FIGS. 4A-4D, the lens 110 in the assembled luminaire 100, is held by inner trough wall 138a and forced into contact with the head of the screws 108. In this depicted embodiment of the luminaire 100, the head of one or more of the screws 108 is sized (height of D) to facilitate this contact between the heads of the screws 108 and the lens 110. This contact holds the screws 108 in the mounting holes 124 and eliminates the need for any holding force between the screws 108 and the mounting holes 124 once the luminaire 100 is assembled. The need for only short term holding force between the screws 108 and mounting holes 124 can further reduce the requirements of the mounting hole 124 and the screws 108 allowing them to be even shorter and allowing an even thinner overall luminaire. The short term requirement for this holding force can also reduce the requirements of screws 108, reducing the overall cost of the luminaire 100. In one exemplary embodiment, the height of the screws is just sufficient to prevent the screws 108 from backing off the force with which they press on the PCB 104. In an alternative exemplary embodiment, the lens 110 increases the force with which the screws 108 press on the PCB 104. In one exemplary embodiment, the height D of the head of such screws 108 is 0.190 inches. Alternative embodiments are also contemplated in which the screw 108 is not held by the lens 110 or are rivets through the PCB 104 and through a hole (not depicted) in the housing 102. Other attachment hardware is also contemplated.
The PCB 104 comprises a PCB front face 104a populated with LEDs 106 and a PCB rear face 104b. The PCB rear face 104b is pressed into contact with the housing 102 by the screw 108 to create sufficient contact between the PCB 104 and the housing 102 to allow the housing 102 to act as a heat sink, taking away heat generated by the LEDs 106 and associated circuitry.
With the exception of the LEDs 106, the PCB front face 104a is covered with a reflective coating or covering. In one exemplary embodiment, the PCB front face 104a is covered with a white adhesive paper adhered to the PCB front face 104a. In another embodiment, the PCB front face 104a is covered with a sheet of reflective aluminum (not depicted). The reflective coating or covering covers the PCB from view while, at the same time, redirecting light off of the PCB front face 104a rather than absorbing it. Many luminaires, especially those using LEDs, place reflectors or optics near the light sources to redirect light emitted from the light sources to travel out of the luminaire. When using this reflective coating or covering discussed above, the luminaire of the present disclosure does not use any such reflectors or optics. The absence of reflectors and optics allows the distance between the PCB 104 and the lens 110 to be set as low as desired, bounded only by the need to secure the PCB 104 to the housing 102. In this manner, the absence of any reflectors or optics further contributes to a thin (i.e. low-profile) luminaire 100.
In order to further reduce the overall height of the luminaire 100, the light sources are LEDs 106 comprised of 0.25 Watt LEDs rather than larger, more powerful LEDs. Historically, one challenge of using LEDs for area lighting has been that LEDs have traditionally emitted insufficient light to replace more conventional light sources such as incandescent or fluorescent. This deficiency has traditionally been overcome by the use of a matrix of LEDs. However, as the acceptance of LEDs for area lighting has become more accepted, technologies have been driven to increase the lumen output LEDs. As the technologies have advanced in this manner, conventional thinking in the LED lighting industry has been to use the biggest and brightest LEDs available for area lighting. The luminaire 100 of the present disclosure takes advantage of the advances in technology, but bucks traditional thinking by using a larger number of smaller, low output LEDs 106 as opposed to a larger number of larger, higher lumen output LEDs. The use of these smaller, low-output LEDs 106 provides the luminaire 100 two advantages.
First, many manufacturers currently manufacture and sell 1 Watt LEDs. For example, Nichia sells the NS9W383 1 Watt LED. This 1 Watt LED has a height of approximately 0.108 inches. Instead of using these, or other, 1 Watt LEDs, the LEDs 106 used by the luminaire 100 are 0.25 Watt LEDs. In one exemplary embodiment the LEDs 106 are Nichia NS2W757A LEDs. More LEDs 106 are required to provide the luminaire 100 the same lumen output than would be necessary if the 1 Watt LEDs were used. However, the 0.25 Watt LEDs 106 reduce the height of the LEDs by 0.086 inches, allowing further reduction in the overall height of the luminaire 100.
In one embodiment of the disclosed luminaire depicted in FIG. 6, the PCB 104 is populated with 460 Nichia 0.25 Watt NS2W757A LEDs arranged in a matrix spacing them at a pitch of 0.625 inches. When driven at 530 mA, these 460 LEDs emit approximately 37 lumens each for a total of approximately 17,000 lumens. When driven at 650 mA, these 460 LEDs emit approximately 44 lumens each for a total of approximately 20,240 lumens.
Second, it has been found that the larger number of lower Watt and lumen LEDs 106 provide a more even light distribution that is more pleasant to the eye. This more even glow can be expressed as a ratio of the lumens (L) per LED 106 to the pitch (P) of the LEDs 106. In the embodiments disclosed in the preceding paragraph, each of the 460 LEDs are spaced at a pitch P of 0.625 inches. When these LEDs are driven at 530 mA they produce approximately 37 lumens each for a ratio of 59.2 lumens/inch. When these same LEDs are driven at 650 mA they produce approximately 44 lumens each for a ratio of 70.4 lumens/inch. Other lumen outputs per chip and pitches are acceptable. It has been found that a P/L ratio of between approximately 59.2 lumens/inch and approximately 70.4 lumens/inch provide a combined even glow when the 0.25 Watt LEDs are illuminated. This ratio is contemplated as applicable to LEDs of other small wattage.
The accumulation of the above discussed advantages of the disclosed luminaire 100 result in an overall thin (i.e. low profile) luminaire 100. With the height E between the rear of the housing 102 and the housing plate front face 116a (0.193 inches in one exemplary embodiment) minimized to the thickness of a plate necessary for molding the mounting holes 124 in the housing plate front face 116a and the matrix 128 on the housing place rear face 116b, the height E can be less than 0.2 inches and it has been found that a height of 0.193 inches is optimal. Furthermore, use of pliable screws 108, with straight mounting holes 124, spacer bosses 126, thin LEDs 106 and a lens frame trough 138 having an inner trough wall 138a working in conjunction with the screws 108 to precisely control the height of the lens 110 with respect to the PCB 104 and the lowermost extremity of the lens frame aperture 142 creates a high precision, low tolerance stack of parts that facilitate a precisely thin luminaire 100 that eliminates the need for reflectors or optics thus further reducing the thickness of the luminaire 100. The height F between the housing plate front face 116a and the lowermost extremity of the lens frame aperture 142 (0.510 inches in one embodiment) is thus minimized and in conjunction with the minimized height E, provides an overall low profile, highly efficient luminaire 100. In the exemplary embodiment of height E being 0.193 inches and height F being 0.510 inches, the total height of the luminaire is only approximately 0.703 inches and is facilitated by one or more of the above discussed features.
The low height F, minus the low height C of the PCB 104 provides a very low height between the base of the LEDs 106 and the lowermost extremity of the lens frame aperture 142 through which light rays emitted from the LEDs 106 escape the luminaire 100. This resulting low height allows most of the lumens emitted from the LEDs 106 to escape the luminaire 100 without need for reflectors or optics. In the example identified above using 460 Nichia 0.25 Watt NS2W757A LEDs driven at 650 mA to emit a total of 20,240 lumens, it has been found that of the 20,240 emitted lumens, 20,195 escaped the luminaire 100 in this configuration.
In one embodiment of the disclosed luminaire, a driver column 146 extends upward from the rear of the housing plate 116. The driver column 146 may be integral with the housing plate 146 or not integral. In the depicted embodiment, the driver column 146 is integrally cast as part of housing 102. The driver column 146 comprises four wings 148 extending radially from a central axis of the driver column 146. The driver column 148 could comprise greater or fewer wings 148; three in one exemplary embodiment. Each wing 148 extends upward from the housing plate 116, having opposing lateral walls 148a and a circumferential wall 148b at the circumferential perimeter of the driver column 146. In the exemplary depicted embodiment, the circumferential wall 148b extends approximately tangential to the circumference of the driver column 146 and the opposing lateral walls 148a extend approximately perpendicular to the circumferential wall 148b inward generally toward the central axis of the driver column 146. The entire driver column 146, including the wings 148, are depicted as hollow, which is a result of the cost savings available by producing the housing 102, including the driver column 146 as an integral, unitary casting. Other embodiments are contemplated, however. For example, the wings could be solid and/or secured to the housing in an alternative embodiment.
Each wing 148 defines a mounting boss 150 at its top 152 for receiving fixing hardware for mounting a driver box 200 to be associated with the luminaire 100 during installation. In the depicted embodiment, the mounting boss defines a screw hole 154 for receiving a screw, but other fixing hardware is contemplated in the alternative. The mounting boss 152 is limited to the outer portion of each wing 148, leaving a recessed land 156 defined by the four mounting bosses 152.
An aperture 158 is defined at the center of the driver column 146 through the land 156 to allow utilities to pass from the luminaire 100 to the driver box 200. For example, wiring 160 to provide power to the light sources passes through the aperture 158 to deliver power from a driver located in the driver box 200 to the light sources.
In an exemplary embodiment, the aperture 158 is designed to allow air to pass therethrough, even when the wires 160 are present. Air expands and contracts as it is heated and cooled, respectively. As discussed above, the seal created by gasket 112 seals the air in the portions of the luminaire 100 inward of the gasket from the ambient environment. Thus sealed, the expansion and contraction of this sealed air would create air pressure above or below the ambient air pressure unless that sealed air was somehow vented. If the air pressure of this sealed air were to fall below the ambient air pressure, then the luminaire 100 would tend to try to draw air outside the luminaire, along with any dirt, moisture, etc. into the luminaire. Over time, this could tend to break down the seal created by the gasket 112. Allowing air to pass through the driver column aperture 158 allows the luminaire 100 to breath and prevents the luminaire 100 from trying to draw moisture across the seal created by the gasket 112.
In one particular exemplary embodiment of the luminaire 100, a breathing tube 162 is run through the aperture 158 along with the wiring 160 and a sealant 164 fills the remainder of the aperture 158 so that no moisture, air, dirt, etc. can pass through the aperture unless through the breathing tube 162. In one embodiment, the sealant 164 is the same urethane adhesive discussed above. In another embodiment, the sealant 164 is an elastomer. Other sealants 164 are contemplated. In yet another exemplary embodiment, a cylindrical gland 166 having a sealant 164 therein is screwed into threads formed in the aperture 158 and the breathing tube 162 and wiring 160 are run through the sealant 164, which forms a tight seal around the breathing tube 162 and wiring 160 to prevent ingress of any dirt, moisture, air, etc. into the luminaire 100. The gland 166 could be a commercially available liquid tight fitting for individual conductors such as a Conta-Clip brand model PG9, in one example. Other embodiments are contemplated. Regardless of how the sealant 164 is provided, the breathing tube 162 is run into the driver box 200 to prevent rain water, dirt, etc. from entering the breathing tube 162 and running down into the luminaire 100.
The driver box 200 comprises a box having a bottom wall 200a and perimeter walls 200b creating an upwardly open box. The driver box 200 is closed by a cover plate 202 having a central plate 202a and downwardly depending edges 202b along each side of the central plate 202a to direct water, snow, etc. downward past the opening to the driver box 200. In one exemplary embodiment, the central plate 202a extends outward beyond each wall 200b of the driver box to further prevent water, snow, etc. from entering the driver box. The driver box comprises mounting hardware to facilitate securing the cover plate 202 to the driver box 200. In one embodiment, the driver box 200 comprises driver box ears 200c extending from one or more driver box walls 200a and defining a hole therein to receive a screw for securing the cover plate 202 to the driver box 200. In the depicted embodiment, driver box ears 200c extend from two opposing ones of the driver box walls 200a. By extending the driver box ears 200c, and thus the hole in the cover plate 202 to accommodate the screws, outward beyond the driver box walls 200a, any rain, snow, etc. falling through the hole in the driver box cover plate 202 will fall outside of the driver box 200 rather than into the driver box 200. In one possible embodiment, the driver box ears 200c do not extend as high as the driver box walls 200a, but fall just short thereof. This prevents any water that may fall through the screw holes in cover plate 202 from traveling across the driver box ears 200c and into the driver box. Alternatively, the driver box ears 200c may extend as high as the driver box walls 200a, but have a groove extending across the driver box ears 200c between the screw holes and the driver box wall 200a. 
A stem 204 extends downward from the driver box bottom wall 202a. In the exemplary depicted embodiment, the stem 204 is integrally cast with the driver box 200, but other options are contemplated. The stem 204 is configured to slide over the driver column 146 of the luminaire and accommodate the driver column 146 within the stem 204. In one embodiment, the stem comprises a wall 204a having an inner surface defining an opening 204b to receive the driver column 146. A top 204c of the opening 204b may be defined by the driver box bottom wall 202a (as in the depicted embodiment) or by a separate top 204c. The opening top 204c can be shaped to complement all or portions of the top of the driver column 146 so that the driver box 200 will sit securely on the driver column 146. The stem opening top 204c defines a utilities aperture 204d to accommodate the wiring 160 and the breathing tube 162 and gland 166, where present, allowing them to enter the driver box 200. The breathing tube 162 need only enter the driver box 200 and be protected from the elements by the driver box 200 and cover plate 202. The wiring 160 enters the driver box 200 through the utilities aperture 204d and is connected to a driver (not depicted) for providing power to the light sources. One or more hardware apertures 204e are defined in the top 204c and configured to allow screws or the like to pass through and secure into a corresponding one of the screw holes 154 on the driver column 146 to secure the driver box 200 to the driver column 146 and, thus, the luminaire 100.
In one embodiment, the stem wall 204a defines a lower edge 204f and a groove 206 about the entirety of the lower edge 204f. The groove 206 accommodates a gasket 208. In the depicted embodiment, the stem wall 204a is cylindrical and the groove 208 and corresponding gasket 208 are circular. Other embodiments are contemplated.
During installation to a structure 210, the housing 102 is elevated to the structure and the driver column 146 passed through an aperture 210a in the structure. The structure 210 could be, by way of example only, a ceiling or a canopy for a petroleum refill station. The structure aperture 210a could be a pre-existing aperture left over from a previously installed luminaire or it could be a newly constructed aperture. The gasket 208 rests in the groove 206 defined by the stem wall lower edge 204f and becomes compressed when brought into contact with the structure and the stem 204 tightly secured to the driver column 146. When in this compressed state, the gasket 208 forms a seal around the structure aperture 210a to prevent material above the structure (e.g. dirt, water, etc.) from getting to the structure aperture 210a. The ability of the gasket 208 to prevent material from getting to the structure aperture 210a in this manner is predicated on the gasket 208 and the groove 206, in which is resides, being larger than the structure aperture 210a. In one exemplary embodiment, the stem wall 204a is sized to allow the gasket 208 to circumscribe at least a 4 inch diameter structure aperture 210a, which is commonly left behind by pre-existing luminaires. Other dimensions are also contemplated. While this size stem is larger than necessary for some applications, it has also been found that the large size of the stem also assists in providing stability of the structure 210 when the structure is somewhat flexible, such as in a sheet metal canopy as is often found at a petroleum refill station.
The stem 204 is preferably of a height to elevate the driver box 200, or portions thereof, above the height where water, snow, etc. may be allowed to accumulate. For example, a sheet metal canopy a petroleum refill station will often accumulate some water and/or snow during precipitation before that water is directed off the canopy. The height of the stem is preferably designed so that the driver box 200 is above the height to which water and/or snow are likely to accumulate. In this embodiment, the driver within the driver box 200 is more likely to be kept dry than if the stem places the driver box 200 below that height.
A mounting apparatus 300 is depicted in FIGS. 7A-7G which can be used with the luminaire 100 described above, or with a different luminaire. For continuity, the mounting apparatus 300 of the present disclosure will be described in conjunction with the luminaire 100 previously described herein. The mounting apparatus 300 is beneficial in mounting a luminaire, such as luminaire 100, to a mounting structure 302, which may depend from another structure such as a ceiling or the canopy of a petroleum refill station.
The mounting structure 302 comprises four walls 302a forming a rectangular box, square in the depicted embodiment. The mounting structure 302 further comprises a face plate 304 extending between the four walls 302a slightly above their lower distal ends 302b. The face plate 304 lies generally horizontal and defines a face plate aperture 306. The face plate 304 can be separate from the walls 302a or extend integrally from the walls 302 as depicted in FIG. 7B. The mounting structure 302 can be a pre-existing mounting structure in which a different luminaire had been installed or can be newly constructed for installation of a luminaire such as the luminaire 100. However, the mounting assembly 300 finds particular use for installing modern LED-based luminaires (such as luminaire 100) in mounting structures such as mounting structure 302 which is typical for housing older model luminaires such as HID or incandescent luminaires.
The mounting apparatus 300 comprises a mounting plate 308 mounted to the back of a luminaire, such as luminaire 100. The mounting plate 308 optionally defines a mounting plate aperture 308a to allow portions of the luminaire to project through. In the depicted example, the driver column 146 of the previously described luminaire 100 is allowed to project through the mounting plate 308 due to the aperture 308a. Flanges 308b extend upward from each edge of the mounting plate 308 a short distance to contact, or come close to contacting, the mounting structure 302 when installed. A hinge flange 308c extends from a first of the flanges 308b and comprises an extending portion 308c′ and wings 308c′′ extending from opposing sides of the extending portion 308′′. The extending portion 308c′ does not extend to the ends of the first of the flanges 308b, but instead leaves clearance on both ends. The wings 308c′′ extend beyond the ends of the first of the flanges 308b and beyond the edges of the corresponding aperture 306 of the mounting structure face plate 304. In this configuration, the luminaire (such as luminaire 100) may hang from the mounting structure 302 by the wings 308c′′ and may rotate about those wings 308c′′. The clearance left on both ends of the extending portion 308c′ provides clearance between the extending portion and the edges of the corresponding aperture 306 during rotation. During installation, this structure allows an installer to connect the wiring of the luminaire to the power source in the mounting structure 302. The mounting plate 308 can be mounted to the luminaire by screws or other hardware.
A catch 310 optionally extends from the mounting plate 308 adjacent to a second of the flanges 308b extending from the mounting plate 308 on a side opposite to the first of the flanges 308b from which the hinge flange 308c extends. The catch 310 comprises a stem 310a and a hook 310b extending from the flange. In the depicted embodiment, stem 310a is mounted to the mounting plate 308 and extend upward to a stem distal end 310c, while the hook 310b extends downward from the stem distal end 310c angled toward the face plate 302 and extending to a hook distal end 310d that lies outside of the face plate aperture 306 such that when the luminaire 100 is rotated downward from the mounting structure 302, the hook catches the face plate 304 and prevents the luminaire 100 from rotating further. A person seeking to rotate the luminaire 100 further may bend the stem 310a inward a distance sufficient to allow the hook distal end 301d to pass the face plate 304. When rotating the luminaire 100 into the mounting structure, the angle of the hook 310b causes the stem 310a to deflect inward as the hook 310b slides past the face plate 304, allowing the hook 310b to pass the face plate 304 and spring back to an unbiased position after passing the face plate 304. While the mounting apparatus 300 is beneficial without the optional catch 310, the catch 310 is preferable for the above discussed benefits. Other embodiments of a catch are also contemplated.
One or more lock wings 312 are optionally mounted to one lock screw 314 each, which extends vertically through the luminaire 100 and the mounting plate 308 at a location adjacent to the second of the flanges 308b extending from the mounting plate 308 on a side opposite to the first of the flanges 308b from which the hinge flange 308c extends. In the depicted embodiment, the mounting apparatus 300 comprises two lock wings 312, each mounted to one lock screw 314. Each lock screw 314 comprises a head 314a located at the face of the luminaire 100, making the head 314a accessible when the mounting apparatus 300 is in the closed position depicted in FIGS. 7A, 7B and 7D (i.e. fully mounted to the mounting structure 302). The lock screw 314 also comprises a threaded shaft 314b extending through the luminaire 100, through the mounting plate 308 and far enough above the mounting plate 308 such that it extends above the mounting structure face plate 304 when the mounting apparatus 300 is in the closed position.
Each lock wing 312 comprises a lock arm 312a and a stop arm 312b connected by a bridge member 312c. In the depicted embodiment, the lock wing 312 is constructed of sheet metal bent into a U-shaped configuration in which the lock arm 312a constitutes one leg of the U, the stop arm 312b constitutes the other leg of the U and the bridge member 312c constitutes the base of the U. In the depicted embodiment, an optional strengthening flange 312d extends along and perpendicular to the lock arm 312a to provide structural rigidity to the lock arm 312. Each of the lock arm 312a and the stop arm 312b define a screw aperture 312e for allowing the screw shaft 314b to pass through. Optionally, one or both of the screw apertures 312e is threaded so that the lock wing 312 can be threaded onto the screw shaft 314b. Alternatively, or in addition, the lock wing 312 can be mounted to the screw shaft 314b by other means, such as, by way of example only, adhesive.
Each lock wing 312 is mounted on the screw shaft 314b at a distance from the screw head 314a that will locate the lock arm 312a slightly above the mounting structure face plate 304. In this configuration, each lock wing 312 can be rotated about the central axis of its corresponding screw 314 by rotating the screw head 314a of the corresponding screw 314. Rotating the lock wing 312 can bring the lock arm 312a over the mounting structure face plate 304 or over the aperture 306 defined in the mounting structure face plate 304. When the lock arm 312a is over the mounting structure face plate 304, the lock arm 312a prevents the luminaire 100 from rotating about the wings 308c′′ of the hinge flange 308c, thus keeping the luminaire 100 secure to the mounting structure 302. However, when the lock arm 312a is over the aperture 306 defined in the mounting structure face plate 304, the luminaire 100 may freely rotate about the wings 308c′′ of the hinge flange 308c, thus allowing access to the luminaire 100 or removal of the luminaire 100 from the mounting structure 100 (with the above described manipulation of the optional catch 310, if present). In this configuration, locking and unlocking the luminaire 100 to the mounting structure 302 requires only a ninety degree (90°) rotation of the screw head 314a. The stop arm 312b assists a person seeking to lock the luminaire 100 to the mounting structure 302 by contacting the adjacent mounting plate flange 308b before the lock arm 312a has rotated too far. In this manner, the stop arm 312b stops rotation of the lock wing 312 at the appropriate location so that it does not continue rotation and end up over the face plate aperture 306. In the embodiment in which one or more of the screw apertures 312e of the lock wing 312 are threaded to the screw shaft 314b, the stop arm 312b prevents rotation of the lock wing 312 and continued advancement of the screw 314 would draw the lock wing 312 closer to the screw head 314a drawing the luminaire 100 closer to the mounting structure face plate 304, allowing a person to tighten the luminaire 100 up against the mounting structure face plate 304, or leave an gap there between at the option of the person. FIG. 7B depicts one lock wing 312 in the locked position and one lock wing 312 in the unlocked position. Other configurations and operations of the lock wings 312 are contemplated.
Optionally, the driver and/or other utilities can be mounted to the mounting plate 308. In the depicted exemplary embodiment, the mounting plate 308 comprises a driver flange 308d extending upward from the mounting plate and the utilities are attached thereto. By extending the driver flange 308d upward of the mounting plate, the driver is separated from the luminaire housing to remove the heat of the utilities from the housing. The driver flange 308d may also act as a heat dissipation fin to dispel heat from the luminaire housing into the mounting apparatus 300.
FIGS. 7F and 7G depict optional mounting structure extensions 316a, 316b that may be mounted to the inner edge of the mounting structure face plate aperture 306 to extend the edges of that aperture 306 inward if slightly larger than desired for an appropriate fit with the mounting apparatus 300. In operation, the mounting structure extensions 316a, 316b are slide over the inner edge of the aperture 360 onto the face plate to provide a new aperture appropriately sized.
The LEDs of this exemplary embodiment can be of any kind, color (e.g., emitting any color or white light or mixture of colors and white light as the intended lighting arrangement requires) and luminance capacity or intensity, preferably in the visible spectrum. Color selection can be made as the intended lighting arrangement requires. In accordance with the present disclosure, LEDs can comprise any semiconductor configuration and material or combination (alloy) that produce the intended array of color or colors. The LEDs can have a refractive optic built-in with the LED or placed over the LED, or no refractive optic; and can alternatively, or also, have a surrounding reflector, e.g., that re-directs low-angle and mid-angle LED light outwardly. In one suitable embodiment, the LEDs are white LEDs each comprising a gallium nitride (GaN)-based light emitting semiconductor device coupled to a coating containing one or more phosphors. The GaN-based semiconductor device can emit light in the blue and/or ultraviolet range, and excites the phosphor coating to produce longer wavelength light. The combined light output can approximate a white light output. For example, a GaN-based semiconductor device generating blue light can be combined with a yellow phosphor to produce white light. Alternatively, a GaN-based semiconductor device generating ultraviolet light can be combined with red, green, and blue phosphors in a ratio and arrangement that produces white light (or another desired color). In yet another suitable embodiment, colored LEDs are used, such are phosphide-based semiconductor devices emitting red or green light, in which case the LED assembly produces light of the corresponding color. In still yet another suitable embodiment, the LED light board may include red, green, and blue LEDs distributed on the printed circuit board in a selected pattern to produce light of a selected color using a red-green-blue (RGB) color composition arrangement. In this latter exemplary embodiment, the LED light board can be configured to emit a selectable color by selective operation of the red, green, and blue LEDs at selected optical intensities. Clusters of different kinds and colors of LED is also contemplated to obtain the benefits of blending their output.
The various luminaires that have been discussed may be used as outdoor lighting canopies. Each may have within it a single circuit board that contains one or more power supplies, drivers, and long chains of low power LEDs. Examples of these are described in the following figures and text that describes them.
FIG. 8 illustrates an example of a circuit that includes a driver 801 and a long chain of low power LEDs 803 that may be driven by the driver 801, all of which may be on a single circuit board within an outdoor canopy light.
The driver 801 may be an integrated circuit, such as a DT3001 TB (made by Seoul Semiconductor). The driver 801 may receive a full wave rectified sign wave as input power by connecting the positive side of this to input pin 4 and the ground side to input pin 2. This may be supplied, for example, by an AC line voltage that is delivered to an input connection 804. A fuse 805 may protect the circuit from an overload. A full wave bridge rectifier 807 may rectify the AC line voltage. The current that is delivered by the full wave bridge rectifier 807 may be limited, such as by resistor pairs 809 and resistor pairs 811 in each leg of the rectified voltage which may have a low resistance, such as about 20 ohms each. The rectified and current-limited output from the full wave bridge rectifier 807 may be protected against surges in the AC line voltage by a transient voltage suppression diode (TVS) 813 and/or a metal oxide varistor (MOV) 815. Operating points of the driver 801 may be set by various components, such as by a R_set resistor 815 and a R_bld resistor 817.
The driver 801 may deliver a voltage-stepped, current-regulated output at its output, such as at its output pins 11, 10, 9, and 8, with an output pin 2 serving as a ground reference. The driver 801 may deliver current in a voltage-stepped sequence. The first step may provide a ground connection at pin 11, the next step at pin 10, the next step at pin 9, and then the final step at pin 8. The voltage may increase at each step in synchronism with increases in the full wave bridge rectified voltage input on pin 4. The voltage may then step back down, first back to pin 9, then back to pin 10, and then finally back to pin 11, again in synchronism with decreases in the full wave bridge rectified input voltage on pin 4. The driver 801 may repeat this stepped up and then stepped down cycle during each rising and falling portion of each 180 degree segment of the full wave bridge rectified AC line input voltage.
The long chain of low power LEDs 803 may consist of a minimum of 36 or a minimum of 48 low power LEDs connected in series. Each LED may have a power rating that is no more than 1 watt or 0.6 watts. The LEDs may be of any type, such as a Nichia NFSW757D-v1 or NFSL757D-v1. They may emit white light or light of any desired color or color combination.
As can be seen in FIG. 8, the long chain of low powered LEDs 803 may be divided into sub-chains, with each sub chain being driven by one of the stepped outputs from the driver 801. At least one sub-chain may have a minimum of 12 or 16 LEDs connected in series. No sub-chain may have less than 6 or 8 LEDs connected in series. Although only one chain of LEDs is shown in FIG. 8, multiple chains of LEDs may instead be connected in parallel to the various outputs of the driver 801, or each additional chain of LEDs may be connected to a separate driver with separate or (partially or fully) shared support circuitry.
The design illustrated in FIG. 8 and discussed above may not require any electrolytic capacitors and thus may not be susceptible to failures caused by defective electrolytic capacitors when they age.
FIG. 9 illustrates an example of a circuit that includes multiple drivers 801 and 901 and a long chain of low power LEDs 803 that may be driven by multiple drivers 801 and 901 with their outputs connected in parallel, all of which may be on a single circuit board, all within an outdoor canopy light. The circuit in FIG. 9 may be identical to the one shown in FIG. 8, except that the multiple drivers 801 and 901 are being used to drive the same chain of LEDs (or chains of LEDs if more than one chain of LEDs is connected in parallel). The driver 901 may be the same type as the driver 801 or different.
As also shown in FIG. 9, the additional driver 901 may have its own operating point setting resistors 915 and 917, but otherwise may share the power supply and surge suppression components that are also used with the driver 801 and described above. Additional drivers and their associated operating point setting resistors may be added in parallel in the same way to provide added current-driving capability, which may be useful when multiple chains of LEDs are connected in parallel or to match the current needs of a single chain of LEDs.
FIG. 10 illustrates an example of a block diagram of an outdoor canopy light 1001 that may use a single full wave bridge rectifier circuitry 1013 to supply power to multiple sets of driver circuitry/LED chain(s) 1015, 1017, 1019, 1021. The full wave bridge rectifier circuitry 1013 may generate a full wave bridge rectified AC signal, such as the one generated by the power supply illustrated in FIGS. 8 and 9. The full wave bridge rectifier circuitry 1013 may include the line voltage inputs 804, the fuse 805, and the full wave rectifier bridge rectifier 807). Each of the driver circuitry/LED chain(s) 1015, 1017, 1019, 1021 may include one or more drivers, such as the drivers 801 and/or 901, the current limiting resistor pairs 809 and 811, the voltage suppression diode (TVS) 813, the metal oxide varistor (MOV) 815, associated operating set point circuitry, such as the R_sets 815 and 915, the R_blds 817 and 917, and one or more long chains of low power LEDs, such as the long chain of low power LEDs 803. All of the components may again be on a single circuit board, with the full wave bridge rectifier circuitry 1013 being in a central areas and each of the multiple sets of driver circuitry/LED chain(s) 1015, 1017, 1019, 1021 being in one of the four quadrants One or more of these components may instead be placed in other locations. Separate full wave bridge rectifier circuitry may also instead be provided for each of the driver circuitry/LED chain(s) or for sub-groups of them. Similarly, a common set of the current limiting resistor pairs 809 and 811, the voltage suppression diode (TVS) 813, and the metal oxide varistor (MOV) 815 may also instead be used.
FIG. 11 illustrates an example of one quadrant of a long chain of low power LEDs on a single circuit board 1101. An example of one of these LEDs is LED 1103. The light grey area on the circuit board is a foil pattern that may advantageously be used to connect the LEDs in series and that provides electrical connections 1105, 1107, 1109, and 1113 to sub-chains within the chain.
FIG. 12 illustrates an example of a single circuit board 1201 that may be placed within an outdoor canopy light that includes a centralized area 1203 which may contain an input connection for the AC line voltage and four quadrants. Each quadrant may include a long chain of low power LEDs, such as the long chain of low power LEDs 1205, 1207, 1209, or 1211. Each quadrant may also include its own power supply, driver(s) and operational set point components, such as in the areas 1213, 1215, 1217, and 1219 of each quadrant.
Optics may be used to direct the light generated by the LEDs. Separate optics may be used for each LED or section of LEDs. Or all of the LEDs may share the same optics. The canopy lights that have been described may be used for any purpose, such as for outdoor lighting, such as in parking lots and gas stations.
The components, steps, features, objects, benefits, and advantages that have been discussed are merely illustrative. None of them, nor the discussions relating to them, are intended to limit the scope of protection in any way. Numerous other embodiments are also contemplated. These include embodiments that have fewer, additional, and/or different components, steps, features, objects, benefits, and/or advantages. These also include embodiments in which the components and/or steps are arranged and/or ordered differently.
For example, the component values that have been described may be ideal when the input line voltage is 120 VAC. However, other input line voltages may be used instead, such as 240 VAC. In this situation, the typical number of components and/or their values may be adjusted to compensate for this voltage change, as should readily be apparent to those skilled in the art. For example, the number or wattage of the LEDs per chain and sub-chain may be doubled.
Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.
All articles, patents, patent applications, and other publications that have been cited in this disclosure are incorporated herein by reference.
The phrase “means for” when used in a claim is intended to and should be interpreted to embrace the corresponding structures and materials that have been described and their equivalents. Similarly, the phrase “step for” when used in a claim is intended to and should be interpreted to embrace the corresponding acts that have been described and their equivalents. The absence of these phrases from a claim means that the claim is not intended to and should not be interpreted to be limited to these corresponding structures, materials, or acts, or to their equivalents.
The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows, except where specific meanings have been set forth, and to encompass all structural and functional equivalents.
Relational terms such as “first” and “second” and the like may be used solely to distinguish one entity or action from another, without necessarily requiring or implying any actual relationship or order between them. The terms “comprises,” “comprising,” and any other variation thereof when used in connection with a list of elements in the specification or claims are intended to indicate that the list is not exclusive and that other elements may be included. Similarly, an element preceded by an “a” or an “an” does not, without further constraints, preclude the existence of additional elements of the identical type.
None of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended coverage of such subject matter is hereby disclaimed. Except as just stated in this paragraph, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.
The abstract is provided to help the reader quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, various features in the foregoing detailed description are grouped together in various embodiments to streamline the disclosure. This method of disclosure should not be interpreted as requiring claimed embodiments to require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description, with each claim standing on its own as separately claimed subject matter.

## Claims

1. A luminaire comprising: a housing; an input connection within the housing that receives AC line voltage; multiple chains of LEDs within the housing, each chain containing at least 36 LEDs connected in series, and each LED having a power rating of no more than 1 watt and oriented to direct light outside of the housing when illuminated; and multiple LED drivers within the housing that receive power that is extracted from AC line voltage connected to the input connection and provide one or more outputs that drive each of the LEDs within the multiple chains of LEDs.

2. The luminaire of claim 1 wherein:
each chain of LEDs is comprised of multiple sub-chains of LEDs connected in series, each sub-chain containing multiple LEDs in series; and
each of the LED drivers provide a separate output that drives at least one of the chains of LEDs at each of the junctions between each of its sub-chains in a stepped sequence that is a function of the level of voltage of the power that is received by LED driver.

3. The luminaire of claim 2 wherein at least one sub-chain within each chain includes at least 12 LEDs.

4. The luminaire of claim 3 wherein no sub-chain within each chain includes less than 6 LEDs.

5. The luminaire of claim 2 wherein the outputs of at least two of the LED drivers are connected in parallel.

6. The luminaire of claim 2 wherein the outputs of at least one of the LED drivers is connected to one of the chains of LEDs and the outputs of at least one other of the LED drivers is connected to another of the chains of LEDs.

7. The luminaire of claim 1 wherein the input connection, the multiple chains of LEDs, and the multiple LED drivers are all on a single printed circuit board.

8. The luminaire of claim 1 wherein each chain has at least 48 LEDs.

9. The luminaire of claim 1 wherein the power rating of each LED is no more than 0.6 watt.

10. The luminaire of claim 1 wherein the housing forms a canopy light.

11. A luminaire comprising:
a housing;
an input connection within the housing that receives AC line voltage;
at least one chain of LEDs within the housing containing at least 36 LEDs connected in series, each LED having a power rating of no more than 1 watt and oriented to direct light outside of the housing when illuminated; and
at least one LED driver within the housing that receives power that is extracted from AC line voltage connected to the input connection and provides one or more outputs that drive the chain of LEDs.

12. The luminaire of claim 11 wherein:
the chain of LEDs is comprised of multiple sub-chains of LEDs connected in series, each sub-chain containing multiple LEDs in series; and
the at least one driver provides a separate output that drives the at least one chain of LEDs at each of the junctions between each of its sub-chains in a stepped sequence that is a function of the level of voltage of the power that is received by LED driver.

13. The luminaire of claim 12 wherein at least one sub-chain within the at least one chain includes at least 12 LEDs.

14. The luminaire of claim 13 wherein no sub-chain within the at least one chain includes less than 6 LEDs.

15. The luminaire of claim 11 wherein the at least one driver includes at least two drivers whose outputs are connected in parallel.

16. The luminaire of claim 11 wherein the input connection, at least one chain of LEDs, and the at least one driver are all on a single printed circuit board.

17. The luminaire of claim 11 wherein the at least one chain has at least 48 LEDs.

18. The luminaire of claim 11 wherein the power rating of each LED is no more than 0.6 watt.

19. The luminaire of claim 11 wherein the housing forms a canopy light.

20. A luminaire comprising: a housing; an input connection within the housing that receives AC line voltage; at least one chain of LEDs within the housing containing multiple LEDs connected in series, each LED oriented to direct light outside of the housing when illuminated; and multiple LED drivers within the housing that receive power that is extracted from AC line voltage connected to the input connection and provide one or more outputs that drive each of the LEDs within the at least one chain of LEDs.

21. The luminaire of claim 20 wherein:
the at least one chain of LEDs is comprised of multiple sub-chains of LEDs connected in series, each sub-chain containing multiple LEDs in series; and
each of the drivers provides a separate output that drives the at least one chain of LEDs at each of the junctions between each of its sub-chains in a stepped sequence that is a function of the level of voltage of the power that is received by LED drivers.

22. The luminaire of claim 21 wherein the outputs of at least two of the drivers are connected in parallel.

23. The luminaire of claim 21 wherein the outputs of at least two of the drivers are connected to different chains of LEDs.

24. The luminaire of claim 20 wherein the input connection, the at least one chain of LEDs, and the multiple LED drivers are all on a single printed circuit board.

25. The luminaire of claim 20 wherein the housing forms a canopy light.

26. A luminaire comprising: a housing; an input connection within the housing that receives AC line voltage; a chain of LEDs within the housing containing multiple LEDs connected in series, each oriented to direct light outside of the housing when illuminated; and multiple LED drivers within the housing, each of which receive power that is extracted from AC line voltage connected to the input connection and provide an output that drives each of the LEDs within the chain of LEDs, each of the outputs being connected in parallel.

27. The luminaire of claim 26 wherein each LED driver provides multiple stepped outputs at different step levels and wherein each stepped output is connected in parallel with all of the other stepped outputs from the other LED drivers at the same step level.