Patent Grant
8206009
The invention relates generally to light fixtures and more particularly to light fixtures with adjustable optical distributions.
A luminaire is a system for producing, controlling, and/or distributing light for illumination. For example, a luminaire includes a system that outputs or distributes light into an environment, thereby allowing certain items in that environment to be visible. Luminaires are used in indoor or outdoor applications.
A typical luminaire includes one or more light emitting elements, one or more sockets, connectors, or surfaces configured to position and connect the light emitting elements to a power supply, an optical device configured to distribute light from the light emitting elements, and mechanical components for supporting or suspending the luminaire. Luminaires are sometimes referred to as “lighting fixtures” or as “light fixtures.” A light fixture that has a socket, connector, or surface configured to receive a light emitting element, but no light emitting element installed therein, is still considered a luminaire. That is, a light fixture lacking some provision for full operability may still fit the definition of a luminaire. The term “light emitting element” is used herein to refer to any device configured to emit light, such as a lamp or a light emitting diode (“LED”).
Optical devices are configured to direct light energy emitted by light emitting elements into one or more desired areas. For example, optical devices may direct light energy through reflection, diffusion, baffling, refraction, or transmission through a lens. Lamp placement within the light fixture also plays a significant role in determining light distribution. For example, a horizontal lamp orientation typically produces asymmetric light distribution patterns, and a vertical lamp orientation typically produces a symmetric light distribution pattern.
Different lighting applications require different optical distributions. For example, a lighting application in a large, open environment may require a symmetric, square distribution that produces a wide, symmetrical pattern of uniform light. Another lighting application in a smaller or narrower environment may require a non-square distribution that produces a focused pattern of light. For example, the amount and direction of light required from a light fixture used on a street pole depends on the location of the pole and the intended environment to be illuminated.
Conventional light fixtures are configured to only output light in a single, predetermined distribution. To change an optical distribution in a given environment having a conventional fixture, a person must uninstall the existing light fixture and install a new light fixture with a different optical distribution. These steps are cumbersome, time consuming, and expensive.
Therefore, a need exists in the art for an improved means for adjusting optical distribution of a light fixture. In particular, a need exists in the art for efficient, user-friendly, and cost-effective systems and methods for adjusting LED optical distributions of a light fixture.
The invention provides an improved means for adjusting optical distribution of a light fixture. In particular, the invention provides an LED light fixture with an adjustable optical distribution. The light fixture can be used in both indoor and outdoor applications. By adjusting the optical distribution of the light fixture, the light fixture can emit light that mimics light from various non-LED light sources, such as metal halide, high intensity discharge, quartz, sodium, incandescent, and fluorescent light sources.
The light fixture typically includes a member having multiple surfaces disposed along a perimeter thereof. Typically, the surfaces are disposed at least partially around a channel or elongated structure extending through the member. For example, the elongated structure can include a solid or hollow tubular structure used to mount the member within the light fixture or to house one or more wires electrically coupled to the LEDs. The member can have any shape, whether polar or non-polar, symmetrical or asymmetrical. For example, the member can have a frusto-conical or cylindrical shape.
The member can be solid or can include multiple components that are coupled together. For example, the member can include multiple modules coupled together by a cover or one or more fastening devices. Each module can include one or more of the surfaces. If a module breaks or otherwise requires service, the module may easily be replaced by exchanging the module with a different, working module. Replacement of one module does not substantially impact operation of the other modules. Therefore, service times and costs associated with a modular member may be less than that of a solid member.
Each surface is configured to receive at least one LED. For example, each surface can receive one or more LEDs in a linear or non-linear array. Each surface can be integral to the member or coupled thereto. For example, the surfaces can be formed on the member via molding, casting, extrusion, or die-based material processing. Alternatively, the surfaces can be mounted or attached to the member by solder, braze, welds, glue, plug-and-socket connections, epoxy, rivets, clamps, fasteners, or other fastening means.
Each LED can be removably coupled to a respective one of the surfaces. For example, each LED can be mounted to its respective surface via a substrate that includes one or more sheets of ceramic, metal, laminate, or another material. Alternatively, one or more circuitry elements from each LED can be mounted directly to the LED's respective surface without using a substrate or other intermediate material.
The optical distribution of the light fixture can be adjusted by changing the output direction and/or intensity of one or more of the LEDs. In other words, the optical distribution of the light fixture can be adjusted by mounting additional LEDs to certain surfaces, removing LEDs from certain surfaces, and/or by changing the position and/or configuration of one or more of the LEDs across the surfaces or along particular surfaces. For example, one or more of the LEDs can be repositioned along a different surface, repositioned in a different location along the same surface, removed from the member, or reconfigured to have a different level of electric power to adjust the optical distribution of the light fixture. A given light fixture can be adjusted to have any number of optical distributions. Thus, the light fixture provides flexibility in establishing and adjusting optical distribution.
As a byproduct of converting electricity into light, LEDs generate a substantial amount of heat. Accordingly, the member can be configured to manage heat output by the LEDs. For example, if present, the channel extending through the member can be configured to transfer the heat output from the LEDs by convection. Heat from the LEDs is transferred by conduction to the surfaces and to the channel, which convects the heat away. For example, the channel can transfer heat by the venturi effect. The shape of the channel can correspond to the shape of the member. For example, if the member has a frusto-conical shape, the channel can have a wide top end and a narrower bottom end. Alternatively, the shape of the channel can be independent of the shape of the member.
Fins can be disposed within the channel to assist with the heat transfer. For example, the fins can extend from the surfaces into the channel, towards a core region of the member. The core region can include a point where the fins converge. In addition, or in the alternative, the core region can include a member disposed within and extending along the channel and having a shape defining a second, inner channel that extends through the member. The fins can be configured to transfer heat by conduction from the facets to the inner channel. Like the outer channel, the inner channel can be configured to transfer at least a portion of that heat through convection. This air movement assists in dissipating heat generated by the LEDs.
In addition, or in the alternative, one or more heat pipes or vapor chambers can extend through, or come in contact with, the member to transfer heat from the LEDs. For simplicity, the term “heat pipe” is used herein to refer to a heat pipe, vapor chamber, or similar device. For example, each heat pipe can extend between a top end of the member and a bottom end of the member, substantially parallel to a longitudinal axis of the member and/or a longitudinal axis of a corresponding one of the surfaces of the member. At least a portion of each heat pipe is surrounded by a material of the member so that an outside perimeter of the heat pipe engages an inside surface of the member. Each heat pipe includes a sealed pipe or tube made of a thermally conductive material, such as copper or aluminum. A cooling fluid, such as water, ethanol, acetone, sodium, or mercury, is disposed inside the heat pipe. Evaporation and condensation of the cooling fluid causes thermal energy to transfer from a first, higher temperature portion of the heat pipe (proximate one or more corresponding LEDs) to a second, lower temperature portion of the heat pipe (away from the one or more corresponding LEDs). For example, the cooling fluid can cause thermal energy to transfer from a top end of the heat pipe to a bottom end of the heat pipe.
The transferred heat can be dissipated from the heat pipe through convection or conduction. For example, the transferred heat can be convected directly from the second portion of the heat pipe to a surrounding environment. In some cases, one or more fins can be integral or coupled to the second portion of each heat pipe to help dissipate the transferred heat, substantially as described above. In addition, or in the alternative, one or more of the heat pipes can be coupled to an active cooling module (or “forced convection” cooling module), such as a SynJet™ brand module offered by Nuventix, Inc.
In certain exemplary embodiments, each heat pipe or vapor chamber includes a sealing chamber, a working fluid, and possibly a wick. The sealing chamber includes evaporation (hot), adiabatic, and condensation (cold) regions. Heat primarily passes into and out of the heat pipe or vapor chamber through the evaporation and condensation regions. The adiabatic region transfers heat from the evaporation region to the condensation region via the movement of heat carrying vapor of the working fluid with little no decrease in temperature. The adiabatic region also can transport heat away from the emission area of the LEDs to a heat sink or other heat management device.
The evaporation, adiabatic, and condensation regions can be comprised of the same material or a combination of different materials. For example, the regions can be comprised of stainless steel, aluminum, copper, and/or another material. The walls of the evaporation and condensation regions must be sufficiently thin or have high enough conductivity as to not impede the conductive transfer of heat to and from the working fluid. The walls of the adiabatic region can be thicker and of lower conductivity than those of the evaporation and condensation regions. The walls also can be made of a flexible material. The inside of the vapor chamber is evacuated of all other fluids besides the working fluid in its liquid and gas phases.
The working fluid is chosen based on the temperature range needed for the application. In typical LED applications, the working fluid can be water, methanol, or ammonia. For extreme temperature applications, mercury, sodium, or liquid nitrogen can be used. During operation, heat from the LEDs passes through the walls of the heat pipe or vapor chamber to the working fluid inside. The latent heat of vaporation boils the working fluid. The vapor expands, traveling through the adiabatic region to the condensation region, where the latent heat of condensation condenses the vapor. The heat then passes through the chamber walls of the condensation region. In certain exemplary embodiments, the heat can pass from the chamber walls to a heat sink or heat management device. The fluid then returns to the evaporation region via gravity if the condensation region is at a higher elevation than the evaporation region. In applications where the condensation region is not at a higher elevation or there are too many bends in the chamber that obstruct flow, a wick can be inserted into the chamber. The wick can be a groove, sintered powder, fine fiber, screen mesh or any other material that uses capillary action to transport the working fluid in liquid form from the condensation region to the evaporation region.
These and other aspects, features and embodiments of the invention will become apparent to a person of ordinary skill in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode for carrying out the invention as presently perceived.
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description, in conjunction with the accompanying figures briefly described as follows.
The present invention is directed to systems for adjusting optical distribution of a light fixture. In particular, the invention provides efficient, user-friendly, and cost-effective systems for adjusting optical distribution of a light fixture. The term “optical distribution” is used herein to refer to the spatial or geographic dispersion of light within an environment, including a relative intensity of the light within one or more regions of the environment.
Turning now to the drawings, in which like numerals indicate like elements throughout the figures, exemplary embodiments of the invention are described in detail.
In the exemplary embodiments depicted in
In certain exemplary embodiments, a light-sensitive photocell 310 is coupled to the mounting member 110ac. The photocell 310 is configured to change electrical resistance in a circuit that includes one or more of the LEDs 105, based on incident light intensity. For example, the photocell 310 can cause the LEDs 105 to output light at dusk but not to output light after dawn.
A member 110d extends downward from the top surface 110ab, around the channel 110c. The member 110d has a frusto-conical geometry, with a top end 110da and a bottom end 110db that has a diameter that is less than a diameter of the top end 110da. Each outer surface 111 includes a substantially flat, curved, angular, textured, recessed, protruding, bulbous, and/or other-shaped surface disposed along an outer perimeter of the member 110d. For simplicity, each outer surface 111 is referred to herein as a “facet.” The LEDs 105 can be mounted to the facets 111 by solder, braze, welds, glue, plug-and-socket connections, epoxy, rivets, clamps, fasteners, or other means known to a person of ordinary skill in the art having the benefit of the present disclosure.
In the exemplary embodiments depicted in
In the embodiments depicted in
Each facet 111 is configured to receive a column of one or more LEDs 105. The term “column” is used herein to refer to an arrangement or a configuration whereby one or more LEDs 105 are disposed approximately in or along a line. LEDs 105 in a column are not necessarily in perfect alignment with one another. For example, one or more LEDs 105 in a column might be slightly out of perfect alignment due to manufacturing tolerances or assembly deviations. In addition, LEDs 105 in a column might be purposely staggered in a non-linear or non-continuous arrangement. Each column extends along an axis of its associated facet 111.
In certain exemplary embodiments, each LED 105 is mounted to its corresponding facet 111 via a substrate 105a. Each substrate 105a includes one or more sheets of ceramic, metal, laminate, circuit board, mylar, or other material. Each LED 105 is attached to its respective substrate 105a by a solder joint, a plug, an epoxy or bonding line, or other suitable provision for mounting an electrical/optical device on a surface. Each LED 105 includes semi-conductive material that is treated to create a positive-negative (“p-n”) junction. When the LEDs 105 are electrically coupled to a power source, such as a driver (not shown), current flows from the positive side to the negative side of each junction, causing charge carriers to release energy in the form of incoherent light.
The wavelength or color of the emitted light depends on the materials used to make each LED 105. For example, a blue or ultraviolet LED typically includes gallium nitride (“GaN”) or indium gallium nitride (“InGaN”), a red LED typically includes aluminum gallium arsenide (“AlGaAs”), and a green LED typically includes aluminum gallium phosphide (“AlGaP”). Each of the LEDs 105 is capable of being configured to produce the same or a distinct color of light. In certain exemplary embodiments, the LEDs 105 include one or more white LEDs and one or more non-white LEDs, such as red, yellow, amber, green, or blue LEDs, for adjusting the color temperature output of the light emitted from the light fixture 100. A yellow or multi-chromatic phosphor may coat or otherwise be used in a blue or ultraviolet LED 105 to create blue and red-shifted light that essentially matches blackbody radiation. The emitted light approximates or emulates “white,” light to a human observer. In certain exemplary embodiments, the emitted light includes substantially white light that seems slightly blue, green, red, yellow, orange, or some other color or tint. In certain exemplary embodiments, the light emitted from the LEDs 105 has a color temperature between 2500 and 6000 degrees Kelvin.
In certain exemplary embodiments, an optically transmissive or clear material (not shown) encapsulates at least some of the LEDs 105, either individually or collectively. This encapsulating material provides environmental protection while transmitting light from the LEDs 105. For example, the encapsulating material can include a conformal coating, a silicone gel, a cured/curable polymer, an adhesive, or some other material known to a person of ordinary skill in the art having the benefit of the present disclosure. In certain exemplary embodiments, phosphors are coated onto or dispersed in the encapsulating material for creating white light.
The optical distribution of the light fixture 100 depends on the positioning and configuration of the LEDs 105 within the facets 111. For example, as illustrated in
As illustrated in
The optical distribution of the light fixture 100 can be adjusted by changing the output direction and/or intensity of one or more of the LEDs 105. In other words, the optical distribution of the light fixture 100 can be adjusted by mounting additional LEDs 105 to the member 110d, removing LEDs 105 from the member 110d, and/or by changing the position and/or configuration of one or more of the LEDs 105. For example, one or more of the LEDs 105 can be repositioned in a different facet 111, repositioned in a different location within the same facet 111, removed from the light fixture 100, or reconfigured to have a different level of electric power. A given light fixture 100 can be adjusted to have any number of optical distributions.
For example, if a particular lighting application only requires light to be emitted towards one direction, LEDs 105 can be placed only on facets 111 corresponding to that direction. If the intensity of the emitted light in that direction is too low, the electric power to the LEDs 105 may be increased, and/or additional LEDs 105 may be added to those facets 111. Similarly, if the intensity of the emitted light in that direction is too high, the electric power to the LEDs 105 may be decreased, and/or one or more of the LEDs 105 may be removed from the facets 111. If the lighting application changes to require a larger beam spread of light in multiple directions, additional LEDs 105 can be placed on empty, adjacent facets 111. In addition, the beam spread may be tightened by moving one or more of the LEDs 105 downward within their respective facets 111, towards the bottom end 110db. Similarly, the beam spread may be broadened by moving one or more of the LEDs 105 upwards within their respective facets 111, towards the top end 110da. Thus, the light fixture 100 provides flexibility in establishing and adjusting optical distribution.
Although illustrated in
The level of light a typical LED 105 outputs depends, in part, upon the amount of electrical current supplied to the LED 105 and upon the operating temperature of the LED 105. Thus, the intensity of light emitted by an LED 105 changes when electrical current is constant and the LED's 105 temperature varies or when electrical current varies and temperature remains constant, with all other things being equal. Operating temperature also impacts the usable lifetime of most LEDs 105.
As a byproduct of converting electricity into light, LEDs 105 generate a substantial amount of heat that raises the operating temperature of the LEDs 105 if allowed to accumulate on the LEDs 105, resulting in efficiency degradation and premature failure. The member 110d is configured to manage heat output by the LEDs 105. Specifically, the frusto-conical shape of the member 110d creates a venturi effect, drawing air through the channel 110c. The air travels from the bottom end 110db of the member 110d, through the channel 110c, and out the top end 110da. This air movement assists in dissipating heat generated by the LEDs 105. Specifically, the air dissipates the heat away from the member 110d and the LEDs 105 thereon. Thus, the member 110d acts as a heat sink for the LEDs 105 positioned within or along the facets 111.
Heat transfers from the LEDs 105 via a heat-transfer path extending from the LEDs 105, through the member 110d, and to the fins 505. For example, the heat 105 from a particular LED 105 transfers from the substrate 105a of the LED 105 to its corresponding facet 111, and from the facet 111 through the member 110d to the corresponding fin 505. The fins 505 receive the conducted heat and transfer the conducted heat to the surrounding environment (typically air) via convection.
The channel 510 supports convection-based cooling. For example, as described above in connection with
In the embodiment depicted in
Although illustrated in
As with the facets 111 of
The LEDs 105 are mounted to the facets 611 (and/or member 605) by solder, braze, welds, glue, plug-and-socket connections, epoxy, rivets, clamps, fasteners, or other means known to a person of ordinary skill in the art having the benefit of the present disclosure. Each LED 105 is mounted to its respective facet 611 directly or via a substrate 105a that includes one or more sheets of ceramic, metal, laminate, or another material, such as a printed circuit board (PCB) or a metal core printed circuit board (MPCB). For example, each LED 105 can be attached to its respective substrate 105a by a solder joint, a plug, an epoxy or bonding line, or another suitable provision for mounting an electrical/optical device on a surface. Similarly, if a substrate 105a is not used, one or more circuitry elements (not shown) of each LED 105 can be attached directly to its respective facet 611 by a solder joint, a plug, an epoxy or bonding line, or another suitable provision for mounting an electrical/optical device on a surface.
In the exemplary embodiment depicted in
An elongated structure 620 extends through an interior portion or center of the member 605, along a longitudinal axis thereof. The elongated structure 620 includes a solid or hollow tubular member 625 that secures the member 605 to the light fixture 600. For example, a top end 625a of the tubular member 625 can be integral to the member 605 or coupled to the member 605 via one or more threaded nuts 640, screws, nails, snaps, clips, pins, adhesives, or other fastening devices or materials. Similarly, a bottom end 625b of the tubular member 625 can be integral to or coupled to another component of the light fixture 600 via one or more threaded nuts, screws, nails, snaps, clips, pins, adhesives, or other fastening devices or materials. For example, the bottom end 625b can be mounted to a reflector housing 630 of the light fixture 600 via one or more brackets 635 or base plates that are integral or coupled to the bottom end 625b.
In certain exemplary embodiments, the tubular member 625 is hollow and defines a channel (not shown) that extends at least partially along the longitudinal axis of the member 605. The channel can house one or more wires (not shown) electrically coupled between the LEDs 105 and a driver (not shown), thereby shielding the wires from view. The driver supplies electrical power to, and controls operation of, the LEDs 105. For example, the wires can couple opposite ends of each substrate 105a or other circuitry element associated with each LED 105 to the driver, thereby completing one or more circuits between the driver and LEDs 105. In certain exemplary embodiments, the driver is configured to separately control one or more portions of the LEDs 105 to adjust light color and/or intensity. In certain alternative exemplary embodiments, there are multiple drivers that each control one or more of the LEDs 105. For example, each driver can control the LEDs 105 on one of the facets 611.
A person of ordinary skill in the art having the benefit of the present disclosure will recognize that, in alternative exemplary embodiments, the elongated structure 620 can be removed and/or replaced with other means for securing the member 605 within the light fixture 600. For example, in certain exemplary embodiments, the heat pipes 610 can secure the member 605 to the active cooling modules 615 without the need for any separate elongated structure 620.
The heat pipes 610 extend from the top end 605a to the bottom end 605b of the member 605, substantially parallel to the longitudinal axis of the member 605. At least a portion of each heat pipe 610 is surrounded by a portion of the member 605 so that an outside perimeter of the heat pipe 610 engages an inside surface of the member 605. Each heat pipe 610 includes a sealed pipe or tube made of a thermally conductive material, such as copper or aluminum. A cooling fluid (not shown), such as water, ethanol, acetone, sodium, or mercury, is disposed inside the heat pipe 610. Evaporation and condensation of the cooling fluid causes thermal energy to transfer from a first, higher temperature portion 610a of the heat pipe (proximate one or more corresponding LEDs 105) to a second, lower temperature portion 610b of the heat pipe (away from the one or more corresponding LEDs 105). For example, the cooling fluid causes thermal energy to transfer from a top end 610a to a bottom end 610b of the heat pipe 610. In certain exemplary embodiments, an internal wick (not shown) may be used to return the cooling fluid from the second portion to the first portion. If the second portion is disposed at a higher elevation than the first portion, gravity could be used to return the cooling fluid from the second portion to the first portion.
The transferred heat is dissipated from the heat pipe 610 through convection or conduction. For example, the transferred heat is convected directly from the bottom end 610b of the heat pipe 610 to a surrounding environment. In one exemplary embodiment, the number and size of the heat pipes 610 depends on the desired amount of heat energy to be dissipated, the size of the core member 605, cost considerations, and other financial, operational, and/or environmental factors known to a person of ordinary skill in the art having the benefit of the present disclosure. The number of heat pipes 610 also can be based on the number of sections present in a modular version of the core member 605, which is described below with reference to
The member 605 can be used in both new construction and retrofit applications. The retrofit applications can include placing the member 605 in an existing LED or non-LED light fixture. For example, the member 605 can be placed in a metal halide, high intensity discharge, quartz, sodium, incandescent, or fluorescent light fixture. Once inserted into the light fixture, the LEDs 105 can be positioned on the facets 611 of the member 605 to generate an optical distribution that mimics light typically output by such a non-LED light fixture. In certain exemplary embodiments, an optimal optical distribution of the member 605 can be obtained by adjusting the placement and/or configuration of the member 605 within the light fixture and/or by adjusting the placement and/or configuration of the LEDs 105 on the facets 611 of the member 605. The position of the member 605 within the light fixture may or may not correspond to a typical position of a non-LED light element within the light fixture. For example, if a fluorescent lamp traditionally has a horizontal position within a particular fluorescent light fixture, the member 605 may or may not be positioned horizontally when retro-fit within the fluorescent light fixture.
An elongated structure 620 secures the core member 605 within the light fixture 900, with a first end 620a of the elongated structure 620 being integral to or coupled to the member 605, and a second end 620b of the elongated structure 620 being integral to or coupled to a bracket 635 that is mounted within a housing 905 of the light fixture 900. Heat pipes 610 extend through at least a portion of the core member 605 (as described with regard to
The high bay light fixture 1100 of
An elongated structure 620 secures the core member 605 within the light fixture 1200, with a first end 620a of the elongated structure 620 being integral to or coupled to the member 605, and a second end 620b of the elongated structure 620 being integral to or coupled to a bracket 635 that is mounted within a housing 1205 of the light fixture 1200. Heat pipes 610 extend through at least a portion of the core member 605 and into the housing 1205. One or more fins (not shown) or active cooling modules 615 can be integral or coupled to an end 610a of each heat pipe 610, within the housing 1205, substantially as described above.
Heat pipes 610 secure the core member 605 within an interior region 1305a of a reflector housing 1305 of the light fixture 1300. Although illustrated in
The reflector housing 1305 is disposed within another housing 1330. The reflector housing 1305 and all components coupled thereto, including the core member 605, the heat pipes 610, and the active cooling modules 615, are rotatable relative to the housing 1330. In one exemplary embodiment, the reflector housing 1305 and coupled components are capable of rotating in ninety (90) degree increments, allowing for manipulation of the optical distribution of the light fixture 1300. For example, the reflector housing 1305 and components can be rotated by (a) removing or releasing one or more screws (not shown) or other fastening devices securing the reflector housing 1305 within the housing 1330, (b) removing at least a portion of the reflector housing 1305 from the housing 1330, (c) rotating the reflector housing 1305 relative to the housing 1330, (d) aligning the rotated reflector housing 1305 with the housing 1330, and (e) re-securing the reflector housing 1305 to the housing 1330 via the removed or released screws or other fastening devices.
Each module 1610 includes an elongated body having an interior profile that substantially corresponds to an outer profile of at least a portion of the elongated structure 620. An outer surface of each module 1610 includes at least one facet 611. Although each of the modules 1610 depicted in
The modules 1610 are connected together via a cover 1615 and one or more threaded nuts, screws 1620, nails, snaps, clips, pins, adhesives, or other fastening devices or materials. The cover 1615 has an interior profile that substantially corresponds to an outer profile of a top end 1605a of the member 1605. The cover 1615 is disposed over and around at least a portion of the top end 1605a. Apertures 1615a and 1615b in the cover 1615 receive ends of the heat pipes 610 and elongated structure 620, respectively.
If a module 1610 or an LED 105 or heat pipe 610 associated therewith breaks or otherwise requires service, the module 1610 may easily be replaced by exchanging the module 1610 with a different, working module 1610. Replacement of one module 1610 does not substantially impact operation of the other modules 1610. Therefore, service times and costs associated with a modular member 1610 may be less than that of a solid member, such as the core member 605 described above in connection with
Referring now to
In certain exemplary embodiments, the enclosure 1705 can be constructed of glass, acrylic, polycarbonate or other materials known to those of ordinary skill in the art. In one exemplary embodiment, the enclosure 1705 is transparent. Alternatively, the enclosure 1705 is translucent. Further, in another alternative embodiment, the enclosure could include on the inner 1715 or outer 1720 surface thereof or embedded within additional optical structures. Examples of optical structures that are positionable on the inner 1715 or outer 1720 surface of the enclosure 1705 or embedded within the enclosure are prisms, blondels, micro optics. In another alternative embodiment, the inner 1715 and/or outer 1720 surface of the enclosure 1705 is textured to obscure the view of the LEDs 105 on the core member 605. In yet another alternative embodiment, the enclosure 1705 is coated with phosphors. In this example, the coated phosphor enclosure 1705 is typically used with LEDs that emit blue or ultraviolet light.
The use of a textured surface, optical structures, phosphor coatings, translucent materials or a combination thereof with the enclosure 1705 provides a more homogeneous luminous output emitted from the LEDs 105 on the core member 605 by providing a substantially uniform luminous output. Using any of these or a combination of these with the enclosure 1705 also improves the obscuration of the LEDs when viewed from the exterior of the lamp 600. This minimizes striations caused by the radical breaks in luminous continuity due to the multiple LEDs 105 on the core member 605. Using any of these or a combination of these with the enclosure 1705 also spreads the light emitted by the LEDs 105 over a greater area, decreasing the average luminance of light output by the LEDs 105 on the core member 605 and thereby improving visual comfort.
In an alternative to the enclosure 1705 shown and described in
Although specific embodiments of the invention have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects of the invention were described above by way of example only and are not intended as required or essential elements of the invention unless explicitly stated otherwise. Various modifications of, and equivalent steps corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can be made by a person of ordinary skill in the art, having the benefit of this disclosure, without departing from the spirit and scope of the invention defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.
This patent application is a continuation-in-part of U.S. patent application Ser. No. 12/183,499, titled “Light Fixture With an Adjustable Optical Distribution,” filed Jul. 31, 2008, which claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 60/994,371, titled “Flexible Light Emitting Diode Optical Distribution,” filed Sep. 19, 2007, and is related to U.S. patent application Ser. No. 12/183,490, titled “Heat Management For A Light Fixture With An Adjustable Optical Distribution,” filed Jul. 31, 2008. This patent application also claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 61/104,444, titled “Light Emitting Diode Post Top Light Fixture,” filed Oct. 10, 2008, and U.S. Provisional Patent Application No. 61/153,797, titled “Luminaire with LED Illumination Core,” filed Feb. 19, 2009. The complete disclosure of each of the foregoing priority and related applications is hereby fully incorporated herein by reference.
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