Abstract:
An LED array with a plurality of easily replaceable LED assemblies. The LED assemblies are attached to a mounting substrate, e.g., by threaded, electrically insulative fasteners. The LED assemblies are electrically connected in a series by detachable power connect clamps and interconnect clamps. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 (e) to, and hereby incorporates by reference, U.S. Provisional Application No. 61/535,541, filed 16 Sep. 2011. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to LED arrays and, in particular, this invention relates to LED arrays with interchangeable LED assemblies. 
     2. Background 
     High intensity Light Emitting Diode (“LED”) devices present great challenges in designing thermal energy management, optical energy management, and electrical energy management (interconnection). This is a particular problem when designing LED light-emitting systems, which focus high levels of specific wavelength light energy at relatively short distances, such as 10 mm-100 mm. These designs require high-density packaging (mounting) of the LED devices. A method is therefore needed to electrically interconnect existing LED “package” designs to meet the high density, as well as electrical energy, management goals. Because of the high intensity light energy, materials used must withstand the energy emitted at the particular wavelength of the applicable device or system. 
     There is then a need for an LED package, which produces high-intensity radiant energy emitted from a high-density LED array. There is a particular need for an LED package, which can be quickly and easily repaired on-site or altered to provide varying wavelengths of radiant energy. 
     SUMMARY OF THE INVENTION 
     This invention substantially meets the aforementioned needs of the industry by providing an LED array with easily and quickly replaceable LED assemblies. 
     There is provided an LED array comprising a mounting substrate, a plurality of LED assemblies, a plurality of power connect clamps, and a plurality of interconnect clamps. The LED assemblies are attached to the substrate and each have positive and negative electrodes electrically connected to an LED chip. The power connect clamps connect each of a pair of terminal LED assemblies to an electrical power source. The power connect clamps may include a power connect fastener threaded into a power connect aperture. The power connect fastener may be threaded into an electrical connector to connect each of the power connect clamps to the power source. The interconnect clamps connect positive and negative electrodes adjacent LED assemblies such that the LED assemblies are interconnected in an electrical series. Each of the interconnect clamps may have a pair of interconnect fasteners, each of the interconnect fasteners threaded into an interconnect aperture. The interconnect fastener may be threaded against a positive or negative electrode to connect and secure the positive and negative electrodes adjacent LED assemblies into the electrical series. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of the LED array of this invention. 
         FIG. 2  is a perspective view of one embodiment of an LED assembly utilized in the LED array of  FIG. 1 . 
         FIG. 3  is a perspective view of the LED assembly of  FIG. 2  with a lens in place covering the LED chip. 
         FIG. 4  is a perspective view of another embodiment of an LED assembly suitable for use in the LED array of  FIG. 1 . 
         FIG. 5  is a perspective view of a bottom side of a mounting substrate suitable for use with the LED array of  FIG. 1 . 
         FIG. 6  is a perspective view of a top side of the mounting substrate of  FIG. 5 . 
         FIG. 7  is a perspective view of one embodiment of a power connect clamp used in the LED array of  FIG. 1 . 
         FIG. 8  is a perspective view of one embodiment of an interconnect clamp used in the LED array of  FIG. 1 . 
     
    
    
     It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit the scope thereof. 
     DETAILED DESCRIPTION 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. 
     Any references to such relative terms as top and bottom or the like are intended for convenience of description and are not intended to limit the present invention or its components to any one positional or spatial orientation. All dimensions of the components in the attached figures may vary with a potential design and the intended use of an embodiment of the invention without departing from the scope of the invention. 
     Each of the additional features and methods disclosed herein may be utilized separately or in conjunction with other features and methods to provide improved devices of this invention and methods for making and using the same. Representative examples of the teachings of the present invention, which examples utilize many of these additional features and methods in conjunction, will now be described in detail with reference to the drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, only combinations of features and methods disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative and preferred embodiments of the invention. 
     A person of ordinary skill in the art will readily appreciate that individual components shown on various embodiments of the present invention are interchangeable to some extent and may be added or interchanged on other embodiments without departing from the spirit and scope of this invention. 
     Referring to  FIG. 1 , an LED (assembly) array  100  is shown. The LED array  100  includes a plurality of LED assemblies  102  attached to a mounting substrate  104  with a plurality of fasteners such as mounting screws  106 . Power is provided to the LED array  100  by means of power connect clamps  108  and the LED assemblies  102  are interconnected using interconnect clamps  110 . One of the end or terminal LED assemblies  112 ,  114  are disposed at each end of the LED array  100 . 
       FIGS. 2 and 3  show one embodiment of an LED assembly  102 . One suitable LED assembly is available from Luminus Devices, Inc., 1100 Technology Park Drive, Billerica, Mass. 01821 USA, as part number SCBT-120-UV-C14-1382-22. This LED assembly emits electromagnetic radiation primarily in the UV spectrum, with a peak wavelength of 385 nm. The LED assembly  102  has positive and negative electrodes  120 ,  122 , and an LED (chip)  124  in electrical communication with the positive and negative electrodes  120 ,  122 , at least partially by means of an electrical connector (wire) assembly  126 . In the embodiment depicted in  FIG. 3  the LED  124  is covered by a lens  128 . The lens  128  may transmit essentially all radiation emitted from the LED  124  or optionally may filter out selected wave lengths. Apertures  130 ,  132  are defined in the base  134 . In the embodiment shown the positive and negative electrodes extend from opposite longitudinal ends of the base  134 . Mounting apertures  136 ,  138  are defined in respective positive and negative electrodes  120 ,  122 . Other components and features of the LED assembly  102  are known to persons of ordinary skill in the art and are not described herein. 
       FIG. 4  shows an LED assembly  144 , the LED assembly differing from the LED assembly  102  by the presence of respective positive and negative electrodes  146 ,  148 . The electrodes  146   148  differ from the electrodes  120 ,  122  in that the electrodes  146 ,  148  are truncated and lack the apertures  136 ,  138 . 
       FIGS. 5 and 6  show bottom and top surfaces of the mounting substrate  104 , respectively. The mounting substrate  104  defines a plurality of mounting apertures  160 ,  162  and LED affixing apertures  164 ,  166 . In the embodiment depicted, the apertures  160 ,  160  are countersunk, so that connectors, such as nuts can be used to flush-attach the mounting substrate  104  to a surface, such as present in a printing press. The countersink feature allows the affixed nuts to be flush with or be entirely below the top surface  168  and, thereby, permit LED assemblies to be mounted flat against the mounting substrate  104 . Thus, the countersink feature permits LED assemblies to fully contact the top surface  168  when attached thereto. The mounting substrate  104  may be formed from a conductive material, such as copper, aluminum, or the like. 
     As shown in  FIG. 7 , one embodiment of a power connect clamp  108  has respective upper and lower portions  172 ,  174 . A power connect clamp slot  176  is defined between the upper and lower portions  172 ,  174 . In the embodiment shown, the lower portion  174  is tapered to a maximum dimension adjacent the slot  176 . A power connect clamp aperture  178  is defined laterally adjacent the slot  176 . Threaded power connect clamp apertures  180 ,  182  are also formed in the upper portion  172 . The threaded apertures  180 ,  182  accommodate power connect fasteners such as power connect set screws  184 ,  186  or equivalent connectors. In the embodiment depicted, the aperture  180  opens into the aperture  178 . As in the case of the mounting substrate  104 , the clamp  108  may be formed from an electrically conductive material, such as copper, aluminum, or the like. 
     As depicted in  FIG. 8 , one embodiment of the interconnect clamp  110  defines respective upper and lower portions  190 ,  192 . Interconnect clamp slots  194 ,  196  are formed between the upper and lower portions  190 ,  192 . Threaded interconnect clamp apertures  198 ,  200  are formed in the upper portion  190  and open into the respective slots  194 ,  196 . Apertures  202 ,  204  are formed in the lower portion  192  and are aligned with the respective apertures  198 ,  200  in the embodiment depicted. The apertures  198 ,  200  accommodate interconnect clamp fasteners such interconnect clamp set screws  206 ,  208 , or equivalent connectors. As in the case with respect to the mounting substrate  104  and power connect clamp  108 , the interconnect clamp  110  may be formed from electrically connective material, such as copper, aluminum, or the like. 
     The LED array  100  is assembled by attaching a plurality of LED assemblies  102  to the mounting substrate  104  by extending mounting screws  106  through apertures  130 ,  132 , then threading the screws  106  into the mounting apertures  164 ,  166 . As shown in  FIG. 1 , adjacent LED assemblies  102  are disposed in alternating polarity such that the positive electrode of one LED assembly  102  is next to a negative electrode of an adjacent LED assembly  102 . In one embodiment, the electrically insulative fasteners, e.g., screws  106 , are fashioned from an electrically insulative material to maintain electrical isolation between the base of the LED assembly and the mounting substrate. One suitable insulative material is Ultem, a registered trademark for an amorphous thermoplastic polyetherimide (PEI) resin available from SABIC Innovative Plastics IP B.V. besloten vennootschap (b.v.) Netherlands Plasticslaan 1 Bergen op Zoom Netherlands 4612PX. Other suitable synthetic resins may be found by a person of ordinary skill in the art, for example, in the Handbook of Plastics, Elastomers, and Composites, Charles A. Harper, Editor in Chief, Third Edition, McGraw-Hill, New York, 1996, hereby incorporated by reference. 
     The plurality of LED assemblies  102  are interconnected in series by attaching adjacent positive and negative electrodes pairs to an interconnect clamp  110 . Referring to  FIG. 8 , a positive electrode  120  is disposed within one of slots  194 ,  196  and a negative electrode  122  of an adjacent LED assembly  102  is disposed in the other of the slots  194 ,  196 . The positive and negative electrodes are then secured in the slots  194 ,  196  by threading the screws  206 ,  208  until they are securely in contact with the electrodes. Alternatively, high compression spring-loaded contacts may be utilized in lieu of the threaded fasteners, each providing a gas-tight electrical connection. The LED assembly  144  may be utilized in lieu of the LED assembly  102 , for example, if saving space is a consideration. 
     Referring now to  FIG. 7 , LED assemblies  102  at each end of the LED assembly  100 , designated terminal LED assemblies  112 ,  114 , are connected to an electrical power source, for example by securing a wire or other conductor positioned in an aperture  178  of the clamp  108  by means of tightening the set screw  184  within the threaded aperture  180  and tightening the set screw  186  in the aperture  182 . 
     One of the LED assemblies  102  may be replaced for repair or to alter the wavelengths being emitted from the LED array  100 . The LED assembly is removed by disconnecting the positive and negative electrodes from the interconnect clamps or from the interconnect clamp and power connect clamp, if the item being replaced is a terminal LED assembly. The LED assembly replacing the removed LED assembly is then attached to the interconnect clamps or to the interconnect clamp and power connect clamp as the case may be. The newly attached LED assembly is then attached to the mounting substrate by the extending the mounting screws through the apertures  130 ,  132  and threading them into the apertures  164 ,  166 . 
     A person of ordinary skill in the art will recognize that both wire and spade-type electrical conductors can be connectively utilized by the assembly and method of this invention. Additionally, various densities of physical mounting may be attained by varying the dimensions and spacing of the LED assemblies. The various components described herein, and equivalents thereof, may withstand the high thermal and light energy environment produced when the LED assemblies are illuminated. 
     An alternative polarity mounting scheme is utilized to provide series connection of the LED devices, which is a highly efficient, space-saving assembly and interconnection method. If necessary, an individual LED assembly can be removed and exchanged with another individual LED assembly by loosening one or both of the brackets  108 ,  110  and removing the screws  106 . The LED assembly intended to replace the removed LED assembly is then secured within one or both of the clamps  108 ,  110  and to the substrate  104  utilizing the set screws  106 . This allows replacement of malfunctioning LED assemblies as well as on-site maintenance and alteration of wavelengths produced by the present LED array. 
     The present assembly and interconnection method of this invention provides “daisy chaining” in an alternate polarity series circuit by mounting the LED assemblies in an alternative polarity. 
     Due to the surface area of the LED assemblies of this invention and direct contact with a surface area of the mounting substrate, additional thermal transfer away from the LED heat source is provided. 
     Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather, the scope of the invention is to be determined by the appended claims and their equivalents.