In many areas of the lighting industry, elongated luminaires, such as light bars or light battens, are employed. One type of light bar is an light emitting diode (“LED”) light bar which includes a set of LEDs housed within a single package. An LED light bar uses electroluminescence emitted from a semiconductor diode that projects light outward with radiant power.
In many traditional LED light bars, there is usually one LED circuit board inside a tube or batten. However, light bars, such as LED light bars, often provide an unsatisfactory light output at the end areas, such as at each end of the tube. As a result, traditional LED light bars generally provide relatively poor uniformity of light distribution.
LEDs in an LED light bar may generate an amount of heat sufficient to cause thermal expansion of components, such as an LED circuit board. In some types of LED light bars, an LED circuit board may intentionally not be fixed into one place or spot inside of a housing or tube in order to account for the possibility of thermal expansion of components within the housing. Such thermal expansion may, in some instances, cause LEDs to slide away from their original positions within the housing, even by more than 1 mm. If the LEDs do slide from their original positions, light produced by LEDs of the LED light bar may not be uniform. For example, there may be less light emitted on one side of translucent or transparent housing of the LED light bar than is produced on the opposing side of the translucent or transparent housing.
According to an aspect of an example embodiment, a substantially linear luminaire assembly may be provided which includes an elongated translucent or transparent housing, where the housing comprises a first end and a second end. One or more light sources may be at least partially enclosed by the elongated housing. A detachable lens assembly may be affixed at or near at least one of the first end and the second end. The detachable lens assembly may include one or more lenses to improve a uniformity of light ray or beam distribution of light rays emitted by the one or more light sources.
According to an aspect of another example embodiment, a substantially linear luminaire assembly may be provided which includes an elongated translucent or transparent housing, where the housing comprises a first end and a second end. A first circuit board and a second circuit board may be disposed within the housing. The first circuit board may be affixed at or near the first end of the housing. The second circuit board may be affixed to the second end. One or more first light sources may be disposed on the first circuit board. One or more second light sources may be disposed on the second circuit board.
Other features and aspects may be apparent from the following detailed description taken in conjunction with the drawings and the claims.
Features and advantages of the example embodiments, and the manner in which the same are accomplished, will become more readily apparent with reference to the following detailed description taken in conjunction with the accompanying drawings.
Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated or adjusted for clarity, illustration, and/or convenience.
In the following description, specific details are set forth in order to provide a thorough understanding of the various example embodiments. It should be appreciated that various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosure. Moreover, in the following description, numerous details are set forth for the purpose of explanation. However, one of ordinary skill in the art should understand that embodiments may be practiced without the use of these specific details. In other instances, well-known structures and processes are not shown or described in order not to obscure the description with unnecessary detail. Thus, the present disclosure is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features disclosed herein.
In accordance with one or more embodiments, one or more linear luminaires may be utilized which include one or more light sources and may generate a relatively uniform light ray output. In one or more embodiments, a linear luminaire may comprise an LED light bar and the one or more light sources may comprise one or more LEDs. For example, such LED light bars may be utilized within a horticulture implementation, such as to provide light to plants growing such as within a greenhouse or other indoor environment. Various embodiments are discussed herein which include one or more LED light bars. However, teachings discussed herein may also be applicable to embodiments utilizing other types of linear luminaires, for example.
In accordance with one or more embodiments, a detachable lens assembly which includes one or more lenses may be attached to one or more ends of a structure, such as a tub, in which LEDs of a light bar are disposed. The lens assembly may be detachable so that it may be selectively coupled to a particular portion of a transparent or translucent tube or housing of an LED light bar. Such a tube may comprise an elongated translucent or transparent housing and may have respective first and second ends. In one particular example, if LEDs of a light bar are disposed within a tube, such as one formed of glass or some other type of transparent material, such as plastic, lens assemblies may be coupled to or otherwise attached to the tube, such as at or near opposing ends of the tube. Each lens assembly may comprise a material such as plastic and may include one or more lenses to receive light emitting by one or more LEDs of the light bar. In one aspect, each of the lenses may refract or change a direction of propagation of rays of light emitted by one or more corresponding LEDs. By changing directions propagation of the rays of light, uniformity of light rays emitted by the LED light bar may be improved.
A detachable lens assembly may be affixed to one or both ends of a substantially linear luminaire, and may be capable of controlling the ray pattern of emitted light from the luminaire to facilitate the narrowing or collimating of such light. The lens assembly may be selectively positioned in accordance with an embodiment to selectively position one or more lenses disposed within the lens assembly to achieve a desired ray pattern. The lens assembly may facilitate the emission of a narrow ray pattern along a length direction of an LED lens bar or some other type of linear luminaire.
The lens assembly may be affixed at or near one or both of the respective end portions of an LED light bar and may not cover the entire length of the LED light bar. In some embodiments the detachable lens assembly comprises a mechanism for alignment of the lens assembly with light sources (such as LEDs) within the linear luminaire. A mechanism for alignment of the detachable lens assembly may be provided by mechanical connecting parts between the ends of the linear luminaires and the detachable lens assembly. For example, an end cap which may be present at one or both ends of the linear luminaire may include a mechanism for ensuring proper alignment of the detachable lens assembly to the linear luminaire.
In one or more embodiments, a lens assembly may comprise a flexible material, such as plastic, which may be clipped onto a portion of a light bar. Such a clip-on design may enable a human operator to relatively easily attach and/or detach the lens assembly to a linear luminaire such as a light bar or otherwise move the lens assembly without having to adhere the lens assembly to the linear luminaire, such as via use of glue or screws, for example.
In one or more embodiments, a mechanism is provided for reducing possible misalignments or poor alignment of the lens assembly. During operation, a detachable lens assembly may effectively become misaligned relative to LEDs or other light sources disposed within a linear luminaire such as an LED light bar. Such a misalignment may be a result of thermal expansion which may occur when LEDs become heated. In accordance with one or more embodiments, to mitigate the effects of thermal expansion, an LED circuit board on which LEDs are disposed may be split into two different LED circuit boards. For example, instead of using a single relatively long circuit board on which LEDs are disposed within a tube or housing of an LED light bar, two circuit boards may be utilized which do not physically overlap. By using two circuit boards, each circuit board may be physically coupled to opposing ends of the tube. Accordingly, one circuit board may be coupled to one end of a tube of a LED light bar, whereas a second circuit board may be coupled to the opposing end of the LED light bar. Such a design may minimize or otherwise reduce issues introduced by thermal expansion. Accordingly, instead of using a single relatively long circuit board which is not physically coupled to either end of tube of the LED light bar, two circuit boards may be used which are each physically coupled to opposing ends of a tube of the LED light bar. The use of such a split circuit board design may improve uniformity of light rays emitted by the LEDs of the light bar even in the event of thermal expansion of the split circuit board.
In accordance with an embodiment having LEDs disposed on two circuit boards within a tub of an LED light bar, a bracket may be used to fix each circuit board to an end of tube. Upon fixing each circuit board to opposing ends of the tube of the LED light bar, a sufficient gap or distance between the two circuit boards may remain so as to address potential issues introduced via thermal expansion of the circuit boards or other components during operation of the LED light bar.
An end cap may be fixed on the tube ends in one or more embodiments. Such an end cap may have a precise or fixed position relative to LEDs of an LED light bar. A lens assembly having one or more clips disposed thereon may be mated with the end caps in order to precisely locate the lens relative to the LEDs, e.g., to achieve an improved uniformity in light output.
Each LED light bar 105 may be mounted on or otherwise disposed on a particular light bar shelf. Embodiment 100 includes three light bar shelves, e.g., first light bar shelf 110, second light bar shelf 115, and third light bar shelf 120. In one particular implementation, each light bar shelf may be 48 inches in length and 24 inches wide.
In order to improve the level of uniformity, a detachable lens assembly may be utilized to refract or redirect light rays from LEDs disposed at or near respective ends of LED light bar 315 in a direction toward grow field area 320.
Detachable lens assemblies 355 and 360 may include one or more lens to redirect light rays emitted from LEDs 310 disposed at or near respective ends of LED light bar 315 in a direction toward grow field area 320. By using such lens assemblies 355 and 360, a level of light uniformity for light emitted from each end of the LED light bar 315 may be improved.
A particular level of uniformity of light distribution from an LED array, such as is shown in embodiment 350 may be desired, such as to ensure that light is provided evenly across one or more plant disposed within grow field area 320 or for some other implementation. For a particular application, a minimum measurement of light uniformity or light ray uniformity may be desired or even required.
Light ray uniformity may be estimated by measuring a luminesce level or a photon flux within a particular test area. A measurement of photon flux refers to the number of photons per second per unit area. For example, if light rays from LED light bar 315 are to be utilized in an implementation with 18 inches of head space, a measurement of photon flux may be made at various locations 18 inches away from the LED light bar 315. In one example, light incident upon a box having length and width dimensions the same as those of LED light bar 315 located 18 inches from the LED light bar 315 may be measured. After photon flux values have been determined for various points or locations within a test area, measurements of both the minimum measured intensity value and the average photon flux value for all points within the test area may be determined. A calculation of light uniformity may be determined by dividing the measurement of the minimum measured photon flux value by the average luminescence or photon flux value of the test area. A perfectly uniform distribution would have a uniformity value of 100%. However, in an implementation which includes the LED light bar array of embodiment 100, a measurement of light ray uniformity may be about 69%. Such a measurement of 69% light ray uniformity may be unsuitable for an application which requires or desires measurements of uniformity of light ray distribution which are 80% or higher.
In order to improve the uniformity of light ray distribution, one or more lenses may be utilized to distribute light rays more evenly from the LEDs at or near opposing ends of an LED light bar. The one or more lenses may also serve to increase a maximum intensity of a measured light intensity distribution, as discussed further with respect to
In the embodiment shown in
Although only a portion of one end of an LED light bar 605 is shown to which a lens assembly 610 is coupled in the embodiment shown in
As shown in
It should be appreciated that by using the lens assemblies at or near each end of an LED light bar, the light ray uniformity was improved from 69%, as shown in embodiment 400 of
One potential issue with LED light bars is thermal expansion of one or more components thereof during operation. For example, each LED may emit or otherwise output a certain amount of heat during operation and the emission of heat may cause a circuit board on which the LEDs are mounted to expand. However, if the circuit board expands, LEDs on which the circuit board are mounts may therefore be displaced relative to intended locations of the LEDs. Depending on the amount of displacement of each LED, the overall uniformity of light ray distribution of an array of one or more LED light bars may be adversely affected. In some implementations, a circuit board on which LEDs are mounted may not be affixed to any specified location or position within a tub or other assembly of the LED light bar. For example, in an implementation in which a single long circuit board of an LED light board is fixed, the circuit board may potentially crack or otherwise deform as a result of thermal expansion.
To reduce adverse effects of thermal expansion, an embodiment as discussed herein may utilize a split circuit board design. In other words, instead of using a single relatively long circuit board which extends approximately the entire length of an LED light bar and which is not affixed to a tube of the LED light bar at any particular location or position, two separate circuit boards may instead be utilized. For example, each circuit board may be approximately half the length of what a single relatively long circuit board would be. Moreover, instead of permitting the circuit board to essentially “float” within a tube of the |LED light bar by failing to affix the circuit board to a tube if the LED light bar at a particular location, each of the two circuit boards on which LEDs are mounted may be fixed to the tube of the LED light bar. For example, one of the circuit boards may be fixed at one end of the tube of the LED light bar and the other circuit board may be fixed at the other, opposing end, of the tube of the LED light bar. By using such a split circuit board implementation, for example, the displacement of one or more LEDs caused by thermal expansion of a circuit board onto which the one or more LEDs are mounted or otherwise coupled may therefore be reduced.
As illustrated in
The terms, “and”, “or”, “and/or” and/or similar terms, as used herein, include a variety of meanings that also are expected to depend at least in part upon the particular context in which such terms are used. Typically, “or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” and/or similar terms is used to describe any feature, structure, and/or characteristic in the singular and/or is also used to describe a plurality and/or some other combination of features, structures and/or characteristics. Likewise, the term “based on” and/or similar terms are understood as not necessarily intending to convey an exclusive set of factors, but to allow for existence of additional factors not necessarily expressly described. Of course, for all of the foregoing, particular context of description and/or usage provides helpful guidance regarding inferences to be drawn. It should be noted that the following description merely provides one or more illustrative examples and claimed subject matter is not limited to these one or more illustrative examples; however, again, particular context of description and/or usage provides helpful guidance regarding inferences to be drawn.
While certain exemplary techniques have been described and shown herein using various methods and systems, it should be understood by those skilled in the art that various other modifications may be made, and equivalents may be substituted, without departing from claimed subject matter. Additionally, many modifications may be made to adapt a particular situation to the teachings of claimed subject matter without departing from the central concept described herein. Therefore, it is intended that claimed subject matter not be limited to the particular examples disclosed, but that such claimed subject matter may also include all implementations falling within the scope of the appended claims, and equivalents thereof.
The present application is a National Stage application under 35 USC § 371 of International Patent Application No. PCT/US2021/072631 entitled “LINEAR LUMINAIRE ASSEMBLY WITH DETACHABLE LENS ASSEMBLY” which was filed on Nov. 30, 2021, and claims the benefit of U.S. Provisional Patent Application No. 63/119,940 entitled “LINEAR LIGHT BAR WITH CLIP LENS” and filed on Dec. 1, 2020. The entire content of that application is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US2021/072631 | 11/30/2021 | WO |
Number | Date | Country | |
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63119940 | Dec 2020 | US |