This invention relates to light fixtures. More particularly, this invention relates to light fixtures which utilize light-emitting diodes (LEDs) as the light source.
In recent years, the use of LEDs for various common lighting purposes has increased, and this trend has accelerated as advances have been made in LEDs and in LED-array devices, often referred to as “LED modules.” Indeed, lighting applications which have been served by fixtures using high-intensity discharge (HID) lamps and other light sources are now increasingly beginning to be served by LED fixtures. Creative work continues in the field of using LEDs for light fixtures in various applications.
High-luminance light fixtures using LEDs as the light source present particularly challenging problems. High cost due to high complexity becomes a particularly difficult problem when high luminance, reliability, and durability are essential to product success. Keeping electronic LED drivers in a water/air-tight location may also be problematic, particularly when the light fixtures are constantly exposed to the elements.
Dealing with heat dissipation requirements is still another problem area for high-luminance LED light fixtures. Heat dissipation is difficult in part because high-luminance LED light fixtures typically have many LEDs. Complex structures for module mounting and heat dissipation have sometimes been deemed necessary, and all of this adds complexity and cost.
Furthermore, previous fixtures utilizing HID lamps and other non-LED light sources typically require a comparatively large lamp compartment with large reflectors for lighting efficiency. Such fixtures often also require large ballast compartments. These often result in large overall fixture size and a substantially heavy fixture.
In short, there is a significant need in the lighting industry for improved light fixtures and the like using LEDs. There is a need for fixtures that satisfy the problems associated with heat dissipation and appropriate protection of electronic LED driver components. Finally, there is a need for an improved LED-module-based light which is relatively simple, compact and easy and inexpensive to manufacture.
It is an object of the invention to provide an improved LED lighting fixture that overcomes some of the problems and shortcomings of the prior art, including those referred to above.
Another object of the invention is to provide an improved LED lighting fixture that is readily adaptable for a variety of mounting positions and situations.
Another object of the invention is to provide an improved LED lighting fixture with both good protection of electronic LED drivers and excellent heat dissipation from LEDs and drivers.
Yet another object of the invention is to provide an improved LED lighting fixture providing desirable illumination.
Still another object of the invention is to provide an improved LED lighting fixture which is relatively simple and compact.
How these and other objects are accomplished will become apparent from the following descriptions and the drawings.
The present invention is an improvement in LED lighting fixtures. The inventive LED lighting fixture includes a housing having a hollow interior cavity defined by a backwall and a surrounding wall extending therefrom to a forward edge. An LED illuminator is mounted in the housing. And, an LED-support structure extends in the interior cavity from the housing to an LED-supporting surface which positions the LED illuminator in a desired orientation and is spaced from the backwall.
The LED-support structure is a heat sink transferring heat from the LED illuminator to the housing. It is preferred that the LED-support structure is substantially spaced from the surrounding wall. The LED lighting fixture preferably includes at least one interior rib connecting the LED-support structure to the surrounding wall.
In preferred embodiments of the inventive LED lighting fixture, the outer surface of the housing includes a series of fins extending outwardly therefrom. The fins provide further heat dissipation from the LED illuminator.
In some of such embodiments, the LED-support structure extends from the backwall. The housing and the LED-support structure may be preferably integrally formed with the outer surface of the backwall having a region free of outer fins. The housing and the LED-support structure are preferably formed by casting. It is preferred that a finned insert is secured to such region of the backwall free of outer fins such that the rear of the fixture is uniformly finned.
In preferred embodiments, the LED-support structure extends from the backwall. Such LED-support structure is preferably substantially hollow. And, the backwall has an aperture leading into the hollow LED-support structure which allows passage of wiring into the housing interior and to the LED illuminator. The hollow LED-support structure preferably defines an aperture into the housing interior for the passage of wiring into the housing interior from the backwall aperture.
The LED lighting fixture preferably includes an LED driver within the housing interior. It is preferred that the LED driver be secured against the housing, thereby transferring heat from the driver.
The backwall may be substantially planar with the surrounding wall including a wire passage into the housing interior. In such embodiments, a plurality of similar fixtures may be mounted along a mounting surface and powered with daisy-chain wiring.
In some preferred embodiments, the LED-supporting surface supports the LED illuminator substantially at the level of the forward edge of the surrounding wall. The LED lighting fixture preferably includes a cover closing the housing interior. Such cover may be made of suitable metal to serve as an electrical closure for the housing interior. The cover defines an LED aperture exposing the LED illuminator. It is preferred that the cover have a substantially white outer surface to reduce absorption of incident light.
The LED lighting fixture preferably includes a lens member over the LED illuminator and sealingly connected to the housing. The lens member preferably includes a lens portion configured for broad distribution of LED-emitted light and a flange portion about the lens portion. The housing preferably includes an outward collar about the forward edge of the surrounding wall. The flange portion of the lens member sealingly engages the outward collar to provide a weather seal to the housing interior. The LED lighting fixture may include a flange-adjacent gasket between the flange portion and the outward collar.
The LED illuminator is preferably a multi-chip LED module. The module may be a type of LED packages which include twenty five LEDs compactly placed close together and coated by a layer of phosphorus selected to produce different colors of white light such as warm, neutral and cool white light. Such LED packages are highly energy-efficient and have a long operating life.
These packages are compact, high-flux-density light sources. The compact size of such multi-chip LED packages is also highly desirable. They are typically round or square with a diameter or a side length of about 20-26 millimeters and a depth of about 3.5 millimeters. The relatively small dimensions of these modules permit significant reduction in the dimensions of lighting fixtures which utilize such high-luminance compact LED light sources.
Certain embodiments of the inventive LED lighting fixture further include a reflector cup which is positioned at the LED-supporting surface and surrounds the LED illuminator to reflect LED-emitted light in a desired direction. The LED-supporting surface is preferably positioned such that distal edges of the reflector cup are substantially at the level of the forward edge of the surrounding wall.
It is preferred that the LED lighting fixture of further includes a lens member over the LED illuminator and sealingly connected to the housing. The lens member may include a light-transmissive region over the reflector cup for transmitting LED-emitted light and a opaque region covering the housing interior.
The lens member is preferably substantially planar. It is preferred that the housing includes an outward collar about the forward edge of the surrounding wall. The lens member preferably sealingly engages the outward collar. The LED lighting fixture may further include a collar-adjacent gasket between the lens member and the outward collar.
In some alternative embodiments, the LED-supporting surface supports the LED illuminator at an acute angle with respect to the backwall.
The surrounding wall may includes a shield portion in position to intercept a portion of emitted light.
LED-support structure 30 is a heat sink transferring heat from LED illuminator 11 to housing 20. LED-support structure 30 is spaced from surrounding wall 23. LED lighting fixture 10 also includes three interior ribs 12 connecting LED-support structure 30 to surrounding wall 23.
The outer surface 25 of housing 20 includes a series of fins 26 extending outwardly therefrom. Fins 26 provide further heat dissipation from LED illuminator 11.
LED lighting fixture 10 includes an LED driver 15 within housing interior 21. LED driver 15 is secured against housing 20 thereby transferring heat from driver 15.
In the embodiment shown in
LED lighting fixture 10 includes a lens member 40 over LED illuminator 11 and is sealingly connected to housing 20. Lens member 40 includes a lens portion 41 configured for broad distribution of LED-emitted light and a flange portion 42 about lens portion 41. Lens portion 41 includes a series of faucets 410 to refract LED-emitted light. Lens portion 41 is formed by a frontwall 43 and sidewalls 44 extending transversely therefrom. Flange portion 42 extends outwardly from sidewalls 44. Housing 20 includes an outward collar 28 about forward edge 24 of surrounding wall 23. Flange portion 42 of lens member 40 sealingly engages outward collar 28 to provide a weather seal for housing interior 21. LED lighting fixture 10 includes a flange-adjacent gasket 47 between flange portion 42 and outward collar 28.
Inventive LED lighting fixture 10A shown in
Housing 20 and LED-support structure 30 are formed by casting with LED-support structure 30 extending from backwall 22. Housing 20 and LED-support structure 30 are integrally formed with outer surface 25 of backwall 22. Backwall 22 has a region 27 free of outer fins 26. It is seen in
LED lighting fixtures 10A and 10B further include lens frames 46A (see
In LED lighting fixture 10B, light-transmissive region 48 is formed by an aperture through a cover plate 49 which forms the opaque region surrounding the aperture. Lens member 40B overlays cover plate 49.
In fixture 10A, lens frame 46A is substantially planar. It is also 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.