Patent Application
20120281404
This invention relates generally to the field of LED light fixtures and, more particularly, to the field of LED light fixtures for various high-luminance area lighting applications such as roadway lighting, factory lighting, parking lot lighting, commercial building lighting, and the like, and to the manufacture thereof.
In recent years, the use of light-emitting diodes (LEDs) in development of light fixtures for various common lighting purposes has increased, and this trend has accelerated as advances have been made in the field. Indeed, lighting applications which previously had typically been served by fixtures using what are known as high-intensity discharge (HID) lamps are now being served by LED light fixtures. Such lighting applications include, among a good many others, roadway lighting, factory lighting, parking lot lighting, and commercial building lighting.
In many of such products, achieving high levels of illumination over large areas with specific light-distribution requirements is particularly important. One example is fixtures for roadway lighting, an application in which the fixtures are generally placed along roadway edges while light distribution is desired along a significant portion of roadway length and, of course, on the roadway itself—generally to the exclusion of significant light off the roadway. And in such situations it is desirable to minimize the use of large complex reflectors and/or varying orientations of multiple light sources to achieve desired illumination patterns.
Achieving appropriate light distribution while avoiding or minimizing the use of complex reflectors and/or varying orientations of multiple light sources requires the use of lens systems for that purpose. And, where lens alignment plays a role in lens systems, maximizing their effectiveness requires high precision in lens alignment.
At the same time, it must be recognized that what is involved in manufacture of LED light fixtures for roadway illumination and the like is mass, preferably highly efficient, manufacture of light fixtures, rather than manufacture of extremely high-cost precision instruments such as for laboratory usage or the like. More specifically, it is of great importance that the economics of low-cost, high-efficiency manufacture be satisfied, but while still achieving the high-precision lens alignment necessary to maximize performance of high-luminance LED light fixtures for roadway illumination and the like.
The present invention is an improved LED light fixture with high-precision lens alignment, and a high-efficiency manufacturing method for such LED light fixture.
The method of this invention is a method of assembling an LED light fixture of the sort including (a) a heat-conductive structure having a mounting surface, (b) a circuit board having a plurality of LED arrays spaced thereon with a plurality of primary lenses each over a corresponding one of the LED arrays and (c) a one-piece lensing member having a plurality of secondary lenses each positioned to align with a corresponding one of the primary lenses. The inventive method includes: providing a set of mounting holes through the circuit board and a set of alignment holes in the circuit board; providing a set of mounting holes through the one-piece lensing member and a set of alignment protrusions extending from a circuit-board-adjacent surface of the lensing member; providing first and second sets of fastener-receiving cavities in the heat-conductive structure and open at the mounting surface thereof; mounting the circuit board to the mounting surface by inserting a first set of fasteners through the circuit-board mounting holes into the first set of fastener-receiving cavities; aligning the lensing member with respect to the circuit board by mating engagement of the alignment protrusions with the alignment holes; and installing the lensing member over the circuit board by inserting a second set of fasteners through the lensing-member mounting holes into the second set of fastener-receiving cavities.
The lighting apparatus of this invention includes: (1) a plurality of primary lenses each over a corresponding LED array, the LED arrays spaced on a circuit board, the circuit board having a first mating feature; and (2) a one-piece lensing member over the circuit board, the circuit board including a plurality of secondary lenses each spaced over a corresponding one of the primary lenses, the one-piece lensing member having a second mating feature positioned and configured for mating engagement with the first mating feature, the first and second mating features engaged to accurately align the secondary lenses over their corresponding primary lenses.
In some embodiments, the second mating feature is a protrusion extending from a circuit-board-adjacent surface of the one-piece lensing member, and the first mating feature is a complementary hole formed in an LED-supporting surface of the circuit board. In such embodiments, the lensing member may have first and second protrusions extending from its circuit-board-adjacent surface, and the circuit board defines (a) a first hole complementary in shape to the first protrusion to fix the position of the lensing member along the circuit board and (b) a second hole receiving the second protrusion to prevent rotation of the lensing member about the first protrusion. The second hole may be elongate along a line extending between the first and second holes to facilitate engagement of the mating features.
Certain embodiments of the present invention also include the heat-conductive structure including a mounting surface to which the circuit board and the lensing member are secured. The heat-conductive structure has first and second sets of fastener-receiving cavities open at the mounting surface. The circuit board is mounted to the heat-conductive structure with fasteners extending through mounting holes in the circuit board and into the first set of fastener-receiving cavities. The one-piece lensing member is secured to the heat-conductive structure by fasteners inserted through holes in the one-piece lensing member and into the second set of fastener-receiving cavities.
The one-piece lensing member may have a peripheral portion extending beyond the edge of the circuit board. Such peripheral portion preferably encircles the circuit board and engages a gasket providing a weathertight seal around the circuit board. The one-piece lensing member may be of a polymeric material, and compression-limiting inserts are in each of the holes of the one-piece lensing member.
Precise alignment of lenses give the full light-distribution benefits that are intended is achieved by this invention, while still allowing highly-efficient assembly.
In descriptions of this invention, including in the claims below, the terms “comprising,” “including” and “having” (each in their various forms) and the term “with” are each to be understood as being open-ended, rather than limiting, terms.
In the inventive method, a set of mounting holes 33 is provided through circuit board 30 and a set of alignment holes 34 is provided in the circuit board 30, as best seen in
As seen in
It is best seen in
While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12610077 | Oct 2009 | US |
| Child | 13441571 | US |
