Abstract:
Systems and methods for mounting optics to an LED lighting module include a retainer engageable with the lighting module and a removable upper plate for securing the optics in the retainer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 61/617,324, filed on Mar. 29, 2012, the entire disclosure of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The technology disclosed herein relates, in general, to light emitting diodes (LEDs) and, more specifically, to systems and methods for mounting replaceable optics in an LED lighting module. 
       BACKGROUND 
       [0003]    LED lighting sources are an increasingly popular choice over traditional incandescent bulbs due to their lower energy consumption, smaller size, and longer operational lifetime. In contrast to lighting sources that emit light in all directions, which intrinsically increases energy losses, LEDs emit light beams with high directionality (e.g., beam angle between 90° and 120°). LEDs, therefore, ideally radiate light in the desired direction with almost no reflective loss. In practice, however, the LED beam angle may nonetheless be too wide for use in a lighting fixture. Secondary optics, such as a total internal reflection (TIR) optic, are utilized to collimate lambertian light from an LED to a more focused beam angle (e.g., ±6°). 
         [0004]    Conventionally, a retention mount is used to position a secondary optical element at the correct location relative to the LEDs. Typical retention mounts, however, receive only a single optic; as a result, multiple mounts are employed when more than one secondary optic is required for a particular illumination application. Once affixed to a mount, the optics are generally sealed within the LED lighting module to keep the optics in place; this makes replacement of a damaged optic difficult or impossible. 
         [0005]    Consequently, there is a need for an optic mount that can removably receive multiple optics in an LED lighting module, and which does not require sealing to maintain configurational stability. 
       SUMMARY 
       [0006]    In various embodiments, the present invention relates to systems and methods for removably mounting multiple optics in a retainer that is firmly attached to the LED lighting module. The retainer correctly positions the secondary optics at desired locations relative to the LEDs. If the optics need to be removed or replaced, an upper plate that firmly holds the optics in place in the retainer may be easily detached therefrom, thereby leaving other components (e.g., the LED circuitry) in the LED lighting module undisturbed. Additionally, because each retainer may include multiple retention regions, multiple retained optics may coexist within a single LED lighting module while maintaining a desired overall beam pattern. As used herein, the term “LED lighting module” refers to a system or assembly that includes the actual LED(s) and support and/or driver circuitry. 
         [0007]    Accordingly, in one aspect, the invention pertains to a system for mounting optics to an LED lighting module including one or more LEDs connected thereto and circuitry for the one or more LEDs. In various embodiments, the system includes a retainer engageable with the lighting module and including one or more retention region configured to retain one or more optical element in a fixed configuration with respect to the one or more LEDs; and a removable upper plate for securing the one or more optical element in the retainer without contacting the circuitry. 
         [0008]    In various embodiments, the retainer is engageable to a heat sink of the LED lighting module and the heat sink is disposed below the one or more LEDs. In addition, the system may include a thermally conductive material applied in a gap between the retainer and the heat sink for efficiently dissipating waste heat. In one implementation, the retainer includes multiple retention collars, each retainably accommodating a geometry of an individual optical element. The retention collar may include a retention element protruding therefrom for retaining the optical element. In addition, an inner surface of the retention collar may frictionally engage the optical element. 
         [0009]    The system may further include means for facilitating removable clamping of the upper plate to the retainer. In one embodiment, the system includes an adjustment element for adjusting a position of the optical element in the fixed configuration. 
         [0010]    In another aspect, the invention relates to a method of mounting one or more optical element to an LED lighting module including multiple LEDs. In various embodiments, the method includes positioning the one or more optical element in a retainer at a desired position relative to one or more LEDs; and removably securing the retainer to the lighting module such that the optical element is fixedly retained at the desired position without contact with any circuitry. In one implementation, the method further includes adjusting the optical elements in the retainer using an adjustment element. 
         [0011]    The optical element may be secured to the retainer by an upper plate engageable with the retainer. In addition, the optical element may be retained in the retainer by an element protruding therefrom. In various embodiments, an inner surface of the retention collar frictionally engages the optical element. In one implementation, the retainer is removably secured by an upper plate. 
         [0012]    Reference throughout this specification to “one example,” “an example,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present technology. Thus, the occurrences of the phrases “in one example,” “in an example,” “one embodiment,” or “an embodiment” in various places throughout this specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, routines, steps, or characteristics may be combined in any suitable manner in one or more examples of the technology. The headings provided herein are for convenience only and are not intended to limit or interpret the scope or meaning of the claimed technology. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, with an emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which: 
           [0014]      FIG. 1  is an exploded view of an LED lighting system in accordance with an embodiment of the present invention; 
           [0015]      FIG. 2A  is an exploded view of a mounting system in accordance with an embodiment of the invention; and 
           [0016]      FIG. 2B  is an exploded view depicting retention collars of a mounting system incorporating features for gripping the optical elements in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1  illustrates an LED lighting system  100  that includes an LED lighting module  110  and a mounting system  112 . The LED lighting module  110  may include a circuit board  114  on which at least some of the LED lighting module components, including the LED(s)  116 , LED supporting circuitry  118  and/or LED driver circuitry  120 , are assembled. Circuitry  118 ,  120  is conventional; for example, the supporting circuitry  118  may include one or more of a current-regulation circuit, a temperature-sensing circuit, a light-sensing circuit and/or a dimming circuit and the driver circuitry  120  provides power to the LED(s)  116  (e.g., converting power from the AC mains to a suitable DC operating voltage). In some embodiments, the circuit board  114  may be a printed circuit board (PCB), a metal plate or other conductive or non-conductive material with circuit traces electronically connecting the LED(s)  116 , supporting circuitry  118 , and/or driver circuitry  120 . For example, the circuit board  114  may be made of a lightweight material having a high thermal conductivity (e.g., aluminum). At least a part of the circuit board  114  is anodized to provide electrical isolation between various electronic components. In one embodiment, the electrical isolation is created using, for example, a thin-film deposition process. 
         [0018]    In some embodiments, the LED lighting module  110  includes a heat sink  122  (typically made of metal or another highly thermally conductive material) for dissipating the heat generated by the supporting circuitry  118 , driver circuitry  120  and/or LED(s)  116 . The circuit board  114  and/or the heat sink  122  may include a flat or curved bottom surface  124  that is capable of attaching or conforming to a variety of surfaces in various lighting applications. In addition, the bottom surface  124  may be made of a substantially rigid or slightly flexible material, such as plastic, metal, and/or another suitable material to accommodate deformation in the course of installation or use. 
         [0019]    In one embodiment, the LED lighting module  110  includes various combinations of red-, green-, and/or blue-emitting LED(s)  106  and emits various colors of light or substantially white light derived from the mixture of the red, green, and blue light. LED(s)  106  may also include amber-emitting LED(s). In addition, the output characteristics (such as light uniformity, dimming, brightness, or color) of the LED lighting module  110  may be regulated by varying the current passing through the LED(s)  106  and/or by altering the duration of operation of the LED(s)  106  using the LED driver circuitry  120  and/or the supporting circuitry  118 . For example, the color of light emitted by the LED lighting module  110  may be established by adjusting the output emission levels of differently colored LED(s)  106  so that the color-mixed output corresponds to a desired color. This may be implemented by changing the current level through each of the differently colored LED(s)  106  or the duration of operation of the LED(s)  106 . 
         [0020]    Referring to  FIG. 2A , in various embodiments, the mounting system  112  includes a retainer  202  to accommodate one or more optical elements (such as lenses or reflectors)  204  and an upper plate  206  to ensure that the optical elements  204  are positioned correctly in the retainer  202 . The retainer  202  may include multiple retention collars  208  each configured to hold an optical element  204 . For presentation purposes, only three optical elements  204  are depicted in  FIG. 2A ; in practice, any number of optical elements  204  may be accommodated by the mounting system  112 . The geometry of the retention collars  208  in the retainer  202  may be shaped and/or sized to accommodate various types of optical elements  204  such that the optical elements  204  can “nest” therein. 
         [0021]    Thus, the retention collars  208  may be the same or different from each other depending on the mounted optical elements  204  and/or the desired beam pattern. For example, if the optical elements  204  have identical circumferences, the retention collars  208  may be identical in size and shape such that any of the optical elements  204  can be placed in any of the retention collars  208  of the retainer  202 . If the optical elements  204  vary in geometry, however, the retention collars  208  in the retainer  202  may be customized such that each optical element  204  may be received in a complementary retention collar  208 . In a preferred embodiment, each retention collar  208  supports a single optic element  204 . However, a single retention collar  208  may hold multiple optical elements  204  as well; for example, optical elements  204  may be shaped and placed in contact with one another such that there is no space therebetween and the multiple optical elements  204  may then be fitted within the single retention collar  208 . Additionally, the height h of the retainer  202  may be varied to accommodate differently sized optical elements  204  and facilitate proper placement relative to the LED lighting module  110  (e.g., directly above one or more LEDs at a desired distance therefrom). The retainer  202  may be firmly mounted to the lighting module  110  by a securing element, for example, one or more screws  210 ; this prevents any lateral movement between the retainer  202  and the lighting module  110 . In some embodiments, the securing element may be a machine fastener (e.g. a clip) or magnetic fastener. In one embodiment, the retainer  202  is mounted to the heat sink  122  of the LED lighting module  110 . In addition, materials having high thermal conductivity may be filled into a gap between the retainer  202  and the heat sink  122  to increase the efficiency of dissipating waste heat. Because the retainer  202  directly or indirectly contacts the heat sink  122  only, the LED(s)  116  and the circuitry  118 ,  120  remain undisturbed during assembly and disassembly of the mounting system  112  and the LED lighting module  110 . In some embodiments, the retainer  202  is made of inexpensive materials, such as plastic. 
         [0022]    Once the retainer  202  is securely attached to the LED lighting module  110 , the optical elements  204  may be placed in the retention collars  208 . The optical elements  204  are tightly secured in positions inside the retainer  202  to prevent movement or rattle. In various embodiments, the retention collars  208  grip the optical elements  204  predominantly via the friction between the optical elements  204  and the inner surfaces of the retention collars  208 . In one embodiment, the inner surfaces of the retention collars  208  are roughened or textured, or provided with an inner-diameter coating or ring of, for example, rubber, in order to increase the static friction. 
         [0023]    In various embodiments, the retention collars  208  incorporate another mechanism (preferably adjustable) for gripping the optical elements  204 . Referring to  FIG. 2B , the retention collars  208  may incorporate, for example, a ball, a rod, a compression spring, flexure bearing or other protruding feature  212  that exerts force against the optical elements  204 ; the features  212  are preferably rounded and/or cushioned or coated with elastic material to avoid damage to the optical elements  204 . In some embodiments, the positions and orientations of the optical elements  204  in the retention collars  208  may be finely adjusted using adjustment components  214  (such as fine screws or removable knobs), ensuring that light emerges from the optical elements  204  with the proper beam angle and/or width. In some embodiments, the fine adjustments may place the optical elements  204  in axial alignment (i.e., making them substantially co-axial) with the optical center line of the LED(s)  106  or the LED lighting module  110 , and/or may position the optical elements  204  at a required elevation above the LED lighting module  110 . When the optical elements  204  reach the correct positions relative to the LED lighting module  110 , the upper plate  206  may be attached to the retainer  202  by a securing element, for example, one or more screws  216 . Pressure is desirably applied uniformly against the optical elements  204  when the upper plate  206  is secured to the retainer  202 . The shape and size of the upper plate  206  and/or the top surface of the optical elements  204  may be customized to make the LED lighting system  100  compatible with various lighting applications. In one embodiment, the upper plate  206  includes an element (such as one or more posts  218 ) for facilitating manipulation and/or installation thereof. In another embodiment, if a flat upper surface of the mounting system  102  is desired, the post(s)  218  is removed. 
         [0024]    During LED operation, if the optical elements  204  are to be removed or replaced, the upper plate  206  may be, for example, simply unscrewed and detached from the retainer  202 . The optical elements  204  may then be removed or replaced with new optical elements without disturbing the LED(s)  106 , circuitry  118 ,  120  or the circuit board  114  of the lighting module  110 . After the new optical elements  204  are correctly positioned, the upper plate  216  may be clamped to the retainer  202  again, as described above. Embodiments of the current invention thus provide for convenient access to and adjustment or replacement of optical elements  204  in an LED lighting system without disturbing the LED(s), circuitry or other operative components. 
         [0025]    The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive.