The present invention relates to underwater lighting, and more particularly to underwater LED lighting.
The light distribution provided by light-emitting diode (LED) lamps is difficult to control in underwater lighting applications. The reason for this is that light distribution is accomplished by introducing one or more lenses. Lenses function based on the principle of Snell's law, which describes how light bends when it transitions between mediums having different indexes of refraction. The index of refraction for lens materials is comparable to the index of refraction for water. Thus, the effectiveness of a lens becomes significantly diminished when the lens is submerged in water. A lens can effectively control the direction of light when the lens is in air, but the same lens has significantly less ability to control the light when the lens is in water.
It is also noted that LED light sources naturally produce a Lambertian pattern of light, which means they are somewhat directional light sources. Lamps that are designed to produce a broader pattern of light using LED light sources need to achieve higher levels of light bending, for example, by including one or more lenses to control the light emitted from the LED.
An application where these practicalities can be problematic is in underwater pool lighting. One such problem occurs where the light from a pool lamp that is emitted higher than approximately 40 degrees above horizontal. In this condition, the light exceeds the Total Internal Refraction (TIR) angle at the surface of the water. This light therefore exits the water and creates a high-glare condition on the side of the pool opposite the lamp. (See
The present invention is an underwater lamp including two or more LEDs positioned on non-coplanar surfaces which allows for light to be aimed from offset planes or in nonparallel directions. The present invention controls the directionality and overall pattern of the light by aiming the LEDs according to an intended pattern. This approach takes advantage of the reality that LEDs are somewhat directional light sources to begin with.
The lamp includes two or more LEDs mounted on two or more non-coplanar, geometric planes. Optionally, the lamp may include a transparent protective cover layer over the LEDs. When the lamp with a cover layer is submerged in water, the outer surface of the cover layer contacts the water; and the cover layer is therefore optically coupled with the water. The cover layer may be a clear encapsulating material that does not result in an air gap between the LEDs and the material. Sample materials include, but are not limited to, clear coating, clear potting compound, clear urethane pour-over and clear urethane overmolding. Alternatively, the cover layer may be a lens that results in an air gap between the LEDs and the lens.
In situations where it is desirable to provide a lamp with a wide pattern of light across one or more of its axes, the lamp will require multiple LEDs positioned on different planes.
Lenses can be included in the lamp to provide a secondary role in shaping the emitted beam pattern. However, this alternative will require an air gap between the LEDs and the lens. In addition, the lens must be positioned according to the direction of the LEDs. The plane of the lens should substantially align with the plane of the LEDs.
With the LEDs aimed according to a desired beam pattern, the air gap between the LEDs and the lens can be reduced or eliminated without significant compromise to the intended beam pattern. The advantage of eliminating the air gap is that this approach improves thermal management by reducing or eliminating convection stages within the thermal path.
According to a disclosed embodiment, the underwater lamp includes a circuit trace, a plurality of LEDs on the circuit trace, a substrate supporting the circuit trace and the LEDs, and a cover layer. The circuit trace includes a plurality of non-coplanar portions or circuit segments, and at least some of the LEDs are mounted on the circuit segments to emit light in nonparallel directions or from staggered emission points. The cover layer can include discrete angled portions corresponding to the angled circuit segments.
These and other advantages and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiments and the drawings.
Before the embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The disclosure may be implemented in various other embodiments and of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting to any specific order or number of components. The use of enumeration also should not be construed as excluding from the scope of the disclosure any additional steps or components that might be combined with or into the enumerated steps or components.
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the embodiment as oriented in
A light-emitting diode (LED) lamp with improved light distribution for underwater applications is provided. As will be appreciated from the description herein, the present underwater lamp (a) improves the ability to manage underwater light distribution, (b) provides an illumination area that is better lit, and (c) reduces or eliminates glare at the water surface. The disclosed design also reduces or eliminates the air gap around the LEDs, which improves the efficiency and management of dissipating heat from the LEDs. The underwater lamp may be used for a variety of underwater lighting applications, including lighting for a pool, boat, dock, fountain, water feature, or aquarium.
One embodiment of an underwater lamp is illustrated and generally designated at 10. The underwater lamp 10 generally includes a housing 12, multiple LEDs 30, a circuit trace 40, and a lens frame 60. “Circuit trace” as used in this application includes equivalent, similar, and other suitable technologies, such as a PCB (printed circuit board), multiple PCBs, multiple MCPCBs (metal core printed circuit boards), a flex circuit, a lead frame, and a wire harness.
Referring to
The light emitting segments 18 can be disposed at an angle A (see
The housing 12 sidewall 16 can include side light emitting segments 22, each including an opening 24 therethrough. The side light emitting segments 22 can be disposed at an angle B (see
The internal electrical components of the underwater lamp 10 may include one or more electrically conductive circuit traces 40 and LEDs 30 supported on or by a substrate 41, shown in
Optionally or alternatively, the underwater lamp 10 may include one or more conventional printed circuit boards (PCBs), and the electrical components may be secured to the PCBs and/or the circuit element.
LEDs 30 are a directional light source and any color LED 30 and lens material, described below, may be utilized according to the requirements of the particular application. Optionally, the LEDs can be of different colors, such that underwater lamp 10 can produce light of different colors. Additional electrical components which may be included on the circuit trace 40 include resistors, capacitors, diodes, transistors, photosensors, inductors, microprocessors, light sensors, temperature sensors, or other such electrical devices or components.
The circuit trace 40 can have a primary portion 46 and multiple angled portions or circuit segments 48 extending outwardly from the primary portion 46. The circuit segments 48 can be angled substantially the same as their respective housing 12 light emitting segments 18, and the LEDs can be mounted to the front surface 42 of each circuit segment 48. The circuit segments can include side circuit segments 50, which can also be angled and extend rearward from the primary portion 46. The side circuit segments 50 can be angled substantially the same as their respective sidewall 16 side light emitting segments 22, and the LEDs can be mounted to the front surface 42 of each side circuit segment 50.
Referring to
An optically transparent thermoplastic polymer material can be used to encapsulate the LEDs 30 and at least the front surface 42 of the circuit trace 40. The thermoplastic polymer material encapsulates the LEDs 30 such that there is substantially no air gap between the lens frame 60 and the LEDs 30, the purpose of which will be discussed below. Any additional electrical components included, such as an integrated circuit, resistor, diode, capacitor, conductor, or virtually any other electrical component(s), can also be at least partially encapsulated within the plastic material. It should be understood that electrical conductors included on the circuit trace 40 can be utilized to provide electrical connections to the embedded circuit components and may include a relatively small exposed external surface to provide for electrical connections. Optionally, rather than having exposed portions of the electrical conductors, the electrical conductors can be completely encapsulated in the plastic material, and an electrical connector can be electrically connected to electrical conductors and embedded within the plastic material as disclosed in U.S. Pat. No. 7,909,482, issued Mar. 22, 2011, entitled “Electrical Device Having Boardless Electrical Component Mounting Arrangement” and U.S. Pat. No. 8,230,575, issued Jul. 31, 2012, entitled “Overmolded Circuit Board and Method” which are both incorporated by reference. Further, the lens can be formed in a single shot or a multi-shot process substantially similar to the process described in U.S. Pat. No. 7,909,482. Alternatively, the lens can be formed as a separate piece in the overall assembly.
A lamp fitting 26 can extend rearward from the lens frame 60, forming an opening through which an electrical interface such as a connector, a solder joint, or crimped wiring can extend. The lamp fitting 26 can also provide a way to affix the underwater lamp 10 to a wall fitting (not shown) or other structure in the selected application. As an example, the lamp fitting 26 can be threaded for threadably mounting the underwater lamp 10 to the wall fitting. Alternatively, the lamp fitting 26 may be integral to the housing 12 instead of the lens frame 60. Further, the lamp fitting 26 can include other suitable attachment means.
The circuit trace 40 (in particular, the circuit segments 48 and side circuit segments 50) and lens frame 60 (in particular, the angled and side lens portions 66, 68) can be disposed within the angled light emitting segments 18 and side light emitting segments 22 of the housing 12. The lenses 62 of lens portions 66, 68 can be visible through the openings 20, 24 in the housing 12 light emitting segments 18, 22. Respective circuit element circuit segments 48 and lens angled portions 66 can be aligned and parallel relative to one another. Similarly, respective circuit element side circuit segments 50 and lens side lens portions 68 can be aligned and parallel relative to one another. Given this parallel arrangement, the LEDs 30 can be positioned to emit light through the lens frame 60 in a direction substantially perpendicular to the circuity segments 48 and the side circuit segments 50. Accordingly, the angle and positioning of the lens frame portions 66, 68 and circuit element circuit segments 48, 50 defined the angle and the position of the LEDs 30 and therefore control the directionality and the source position of each individual LED. The overall the emitted light and the overall light pattern created by the underwater lamp assembly 10 is thereby defined by the independent angles and positions of the circuit segments 48, 50.
Referring to
The illustrated exemplary embodiment of
The disclosed underwater lamp 10 can include different combinations of lamp subassemblies 70 and side lamp subassemblies 72. For example, in the illustrated exemplary embodiment, the underwater lamp 10 includes three lamp subassemblies 70 disposed on the front surface 14 of the housing 12 and four side lamp subassemblies 72 disposed on the sidewall 16 of the housing 12. In exemplary embodiments where the housing 12 is circular, the lamp subassemblies 70 can be radially spaced from one another and the side lamp subassemblies 72 can be spaced along the sidewall 16 to provide a preselected underwater light pattern as desired for the selected application. Because the circuit trace 40 can be bent into a wide variety of shapes, the present underwater lamp is not limited to a substantially flat configuration as with conventional circuit boards. The present circuit element and LEDs may be configured to illuminate a three-dimensional space dictated by other design considerations such as aesthetics, shape and dimensions of the pool or other application, and the like.
When the underwater lamp 10 is submerged, the polymer material that encapsulates the LEDs 30 can protect the LEDs 30 and circuit trace 40 from exposure to water, therefore protecting against electrical shock and promoting safety. The polymeric material encapsulating the LEDs 30 also permits transmission of light from the LEDs with a minimum transmission loss Eliminating, reducing, or and/or controlling the gap between the lens 62 and the LEDs 30 improves light transmission efficiency.
Additionally, encapsulating the LEDs 30 and lens 62 so that no gap or a reduced and controlled air space is included therebetween improves thermal management of the underwater lamp 10. Direct contact of the lens 62, and thereby the LEDs 30, with the water increases the ability to cool the LEDs 30 and improves both intensity and luminosity of the light. When submerged, the water essentially functions as a large heat sink. The assembly 10, which reduces the air gap between the LED 30 and the lens 62, provides improved thermal management because the thermal path from the LED 32 the water is reduced.
Referring to
While the disclosure herein relates to the pool and spa industry, the present underwater lamp can be used in other applications where submerged lighting can benefit from being managed efficiently and an improved light pattern is desired. Such other applications could include marine, dock, port, fountain, water feature, and aquarium.
The above description is that of current embodiments of the disclosure herein. Various alterations and changes can be made without departing from the spirit and broader aspects of the disclosure as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the disclosure or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described disclosure may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present disclosure is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.
Number | Date | Country | |
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62706690 | Sep 2020 | US |