Abstract:
A lighting apparatus comprises one or more LED modules. Each LED module comprises: an upper housing having an array of raised portions capable of transmitting light therethrough; a PCB layer having LEDs mounted thereon, respective ones of the LEDs being mounted so as to positionally correspond to respective ones of the raised portions; and a lower housing, the lower housing and the upper housing sandwiching the PCB layer so as to permit light emitted by the LEDs to be emitted out of the upper housing.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to back or side lit lighting apparatuses used for lighting, for examples in signage. 
         [0002]    Conventionally, back lit units are fixed position units that do not permit changing of the configuration after installation. That is, once the back lit unit is configured, the display is fixed, which makes any changes to, for example, a sign or display to be quite difficult. 
       BRIEF SUMMARY OF THE INVENTION 
       [0003]    In accordance with a first aspect of the present invention, a lighting apparatus comprises one or more LED modules. Each LED module comprises: an upper housing having an array of raised portions capable of transmitting light therethrough; a PCB layer having LEDs mounted thereon, respective ones of the LEDs being mounted so as to positionally correspond to respective ones of the raised portions; and a lower housing, the lower housing and the upper housing sandwiching the PCB layer so as to permit light emitted by the LEDs to be emitted out of the upper housing. 
         [0004]    In another aspect, the lower housing of each of the one or more LED modules includes one or more connection openings that facilitate connection together of a plurality of LED modules together to form a mosaic of LED modules. 
         [0005]    In another aspect, at least one of the one or more connection openings is operable to receive electrical signals and/or power. 
         [0006]    In another aspect, each raised portion includes an aperture to permit light from respective LEDs to pass through respective raised portions. 
         [0007]    In another aspect, the lighting apparatus further comprises a connector configured to make a snap fit connection between connection openings of adjacent LED modules when a plurality of LED modules are connected together to form a mosaic. 
         [0008]    In another aspect, each connector includes plural male portions adapted to mate with corresponding female portions provided in the connection openings. 
         [0009]    In another aspect, the lighting apparatus further comprises one or more tiles configured to snap fit over one or more of the raised portions. 
         [0010]    In another aspect, each of the one or more tiles is configured to modify or pass the light emitted from the upper housing. 
         [0011]    In accordance with a second aspect of the present invention, a lighting apparatus comprises one or more LED modules. Each LED module comprises: an upper housing having an upper surface and at least one edge having a slot provided therein; a substantially planar light leading lens having at least one side edge formed in a direction perpendicular to a plane of the light leading lens, the light leading lens being configured so as to mount on the top surface of the upper housing and to lead light received at the at least one side edge; at least one PCB strip having LEDs mounted thereon, the at least one PCB strip, when the LED module is assembled, protruding through the slot so that the LEDs are on the same level as the at least one edge of the light leading lens; and a lower housing comprising at least one slit provided at an outer edge of the lower housing. 
         [0012]    In another aspect, each LED module further comprises a substantially planar transparent tile molding provided above the light leading lens, the transparent tile molding being configured to contact an upper surface of the light leading lens and having a plurality of raised portions operable to direct light from the light leading lens in a direction substantially perpendicular to the plane of the light leading lens. 
         [0013]    In another aspect, the lower housing of each of the one or more LED modules includes one or more connection openings that facilitate connection together of a plurality of LED modules together to form a mosaic of LED modules. 
         [0014]    In another aspect, at least one of the one or more connection openings is operable to receive electrical signals and/or power. 
         [0015]    In another aspect, the lighting apparatus further comprises one or more tiles configured to snap fit over one or more of the raised portions. 
         [0016]    In another aspect, each of the one or more tiles is configured to modify or pass the light emitted from the transparent tile molding. 
         [0017]    In another aspect, the lighting apparatus further comprises a connector configured to make a snap fit connection between connection openings of adjacent LED modules when a plurality of LED modules are connected together to form the mosaic of LED modules. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The figures are for illustration purposes only and are not necessarily drawn to scale. The invention itself, however, may best be understood by reference to the detailed description which follows when taken in conjunction with the accompanying drawings in which: 
           [0019]      FIG. 1A  is an exploded parts view of an individual LED module in accordance with an embodiment of the present invention; 
           [0020]      FIGS. 1B and 1C  are side and top views, respectively, of the LED module shown in  FIG. 1A ; 
           [0021]      FIGS. 2A and 2B  are perspective and magnified views, respectively, of an assembled individual LED module with a plug in connector, in accordance with an embodiment of the present invention; 
           [0022]      FIG. 3  is a bottom perspective view of a lower housing of the LED module shown in  FIG. 1A ; 
           [0023]      FIG. 4A  shows two LED modules and a manner of connecting the LED modules to one another to form a multi-module mosaic, in accordance with an embodiment of the present invention; 
           [0024]      FIGS. 4B and 4C  are views showing one manner of securing an LED module to a wall; 
           [0025]      FIGS. 5A and 5B  are views showing how an end cap is utilized to enclose a connector socket in an LED module in accordance with an embodiment of the present invention; 
           [0026]      FIG. 6  shows an LED module and a power supply connector in accordance with an embodiment of the present invention; 
           [0027]      FIG. 7  illustrates how a plug tile is used in an LED module in accordance with an embodiment of the present invention; 
           [0028]      FIG. 8A  illustrate plug tiles installed at portions of an LED module in accordance with an embodiment of the present invention, and how they can be removed; 
           [0029]      FIG. 8B  illustrates an example of a plug tile with painting on its surface; 
           [0030]      FIG. 9  shows a two module mosaic with multiple installed plug tiles and frame installed, in accordance with an embodiment of the present invention; 
           [0031]      FIG. 10A  is a view of a two LED module mosaic showing the individual parts of the frame in an exploded parts view of the frame; 
           [0032]      FIG. 10B  is a magnified view showing how a part of the frame is attached to an edge of an LED module, in accordance with an embodiment of the present invention; 
           [0033]      FIG. 10C  is a view of a four LED module mosaic, in accordance with an embodiment of the present invention; 
           [0034]      FIGS. 11A and 11B  are plan and side views, respectively, of an LED module in accordance with a second embodiment of the present invention; 
           [0035]      FIGS. 12A and 12B  are bottom and top perspective views, respectively, of an LED module with end cap and connector in accordance with the second embodiment; 
           [0036]      FIG. 13A  is a top perspective view of an LED module in accordance with a side lit embodiment of the present invention; 
           [0037]      FIG. 13B  is a view of an LED module in accordance with a side lit embodiment of the present invention with the transparent tile molding removed; 
           [0038]      FIG. 14A  is an underside view of the upper housing in accordance with a side lit embodiment, with the PCB and LED strips inserted into slots in the upper housing; and 
           [0039]      FIG. 14B  is an exploded parts view of an LED module in accordance with a side lit embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0040]      FIGS. 1A-10C  illustrate a first preferred embodiment of an LED module and mosaic of such modules, in accordance with an aspect of the present invention. As can be seen in the figures, an individual LED module  10  in accordance with the first embodiment of the present invention is formed of an upper housing  12 , having an array of apertured raised areas  14 , preferably integrally formed with the upper housing, for example by molding, a PCB layer  16 , with an array of LEDs  18  mounted thereon, and a lower housing  20 . In the illustrated embodiment, an array of 7×7 (i.e., 49) LEDs are laid out in an array on the PCB layer  16 . An exemplary PCB layer could be, for example, a 150 mm×150 mm PCB with mounted LEDs on top, and circuitry for receiving signals and power on the other side, although the present invention is not limited to any particular dimensions or layout. As would be understood, the LED array in accordance with the present invention is not limited to any particular number. 
         [0041]    The raised areas  14  of the upper housing  12  preferably each include an aperture in a central portion thereof. Preferably, in a back lit embodiment in which the LEDs  18  are sandwiched between the upper housing  12  and the lower housing  20 , the LEDs are mounted on the PCB  16  and each LED  18  fits into the underside of the upper housing in an aperture, as can be seen in the cross-sectional view of  FIG. 1B . This permits the light from the LEDs  18  to emanate from the top of the LED module  10 , through the apertures. As can be seen clearly in  FIG. 1C , for example, when viewed from the top, the LEDs  18  show through the apertures in each raised portion  14 . The upper housing  12  and the lower housing  20  are each preferably formed of plastic or other moldable materials. 
         [0042]    Tiles  30  can be applied to one or more of the raised portions  14  to modify the visual appearance of the light from the apertures. For example, if the tiles  30  are frosted, they can be used to diffuse the light coming from the aperture. Further, as can be seen in  FIG. 8B , the tiles can have painting on the surface, which can be seen by a viewer of, for example, a screen made up of a number of LED modules  10 . Also, tiles can be colored, to color the appearance of the light, clear, which will not change the color, or opaque, e.g., black, to block light from being emitted from one or more apertures covered by the tile. The manner of application can be seen, for example, in  FIG. 7 . The tiles  30  preferably are notched to allow for easy removal using, for example, a screwdriver, as shown in  FIG. 8A . The tiles  30  are preferably made of plastic. 
         [0043]    Combinations of sizes, colors and other characteristics of the tiles  30  allows for a large amount of variation in the appearance of the overall display mosaic. For example, as can be seen in  FIG. 9 , different size tiles can be used in a multi LED module (in this case a 2 LED module) mosaic  44 . As shown in  FIG. 9 , in this example a 4×4 tile (i.e., a tile that covers a 4×4 group of raised portions  14 ) is used to overlap the edge between two adjacent LED modules. The use of the various kinds and sizes of tiles  30  provides the flexibility to have all the LEDs appear to the viewer to be lit, or only a subset of them to appear lit, depending on the type of tile or tiles used, whether the tiles are clear, semi-transparent, opaque, or with textures such as ripples. The tiles can also be asymmetrical and may provide for light at different angles. 
         [0044]    The tiles are not limited to the shapes shown in the figures but may have any shape pleasing to the eye. In addition to various colors and transparencies, tiles could have different textures and/or a 3D visual effect. Tiles can also be formed with an optical design so as to give different light output, for example to as to change the projected shape of the light, for example an optical design that changes light usually projected as a round spot to projected light having different shapes such as a star, square, rectangle, oval or other shape. 
         [0045]    As shown, for example, in  FIGS. 1A to 1C , an individual LED module  10  in accordance with a first embodiment provides a back lit module that is connectable, for example using connectors  26  inserted into one or more of connection openings/sockets  24  formed in the lower housing  20 , to other LED modules, to form a mosaic, with each LED module acting as a tile in the mosaic. When connected together the mosaic forms a panel of a desired size. 
         [0046]    An exemplary manner of connection with the connectors  26  is shown in  FIGS. 2A-4A . As can be seen in those figures, the connectors  26  each include recessed male portions  26   a  which mate with female portions  24   a  in the connector indents  24  of two LED modules to be adjacently connected, to securely connect the two LED modules. This can be repeated in all four directions for each LED module to allow for mosaics of increasing size. The connectors  26  can be of two general types: one type which mechanically links two LED modules without passing electrical signals; and another (active) type that is a DC connector to interconnect the LED modules, e.g., for power and/or electrical signals. Typically no more than one active connector would be used on any one side of an LED module. 
         [0047]      FIGS. 5A and 5B  show an end cap  32  used to enclose an unused connection opening  24 . To promote a secure connection with the connection opening  24 , the end cap  32  is preferably formed so as to have male portions  32   a  that can mate with female portions  24   a  of the connection opening  24 . The use of the end caps  32  may be advantageous, for example, at the outermost edges of the outer LED modules in a mosaic, or in any connection opening that is unused for any reason. The end cap  32  does not pass any signals or power and simply encloses any unused connection openings. 
         [0048]      FIG. 6  shows a power supply connector  33  that can be used to supply electrical signals/power to the PCB layer  16  and the LEDs  18 . The power supply connector is preferably an AC/DC power connector to supply power from a power source, such as a wall outlet, to the PCB layer. In this particular embodiment, the power supply connector  33  is supplied by wiring box  34 , which can be in the form of a plug or other connector to a source of power/signals. Signals from the power supply connector  33 , which would typically be DC, are supplied, for example, to circuitry in the PCB layer  16 , for driving and powering the LEDs. 
         [0049]    As can be seen, for example, in  FIGS. 9 ,  10 A and  10 B, a frame  40  can be snap fitted around the periphery of the assembled mosaic  44 . In the illustrated embodiment, frame  40  consists of frame elements  40   a  to  40   e  that form different shaped elements each having a shape to conform to the shape of the periphery. The frame  40  shown in the figures is used in conjunction with a 2×1 mosaic. However, the frame elements can easily form a frame around mosaics of any size, using various combinations of the frame elements. The frame  40  protects the edges of the assembled mosaic and provides strength to the connection. In addition, the frame functions to provide a pleasing aesthetic appearance by hiding the wires and connectors from being seen. As can be seen most clearly in  FIG. 10B  each frame element has a portion on its inner surface that can be snapped into the track  48  that is provided around each LED module. As shown in  FIG. 10A , frame element  40   d  includes a notch  40   g  that allows the power supply connector to couple with one of the LED modules to supply power to the panel (mosaic) formed by the connected LED modules. The wires will preferably run through the bottom of the lower housing. 
         [0050]    For use in mounting a mosaic, or an individual LED module, the lower housing  20  also preferably is configured/formed so as to have a channel track  22 , which permits mounting of the LED module, alone or in connection with other LED modules  10 , e.g., on a wall or other surface. As can be seen in  FIGS. 4B and 4C , a channel  23  can be first affixed to a wall or other mounting surface by, for example, a screw  23   a . This channel can be used, in conjunction with the channel track  22 , to slidably, or snapably mount one or more LED modules to the wall. 
         [0051]    The lower housing  20  preferably is formed so as to have a buckle  28  that allows the lower housing  20  to snap fit together with the upper housing  12  in assembling the LED module  10 . Once assembled, electrical signals and power connections to the sandwiched PCB layer  16  can be made by means of connectors that may be connected via the connection openings  24 . 
         [0052]    Each LED module has connective elements from the connector to the PCB layer  16  to apply the necessary signals for driving and powering the LEDs  18 . In the event of a failure of PCB layer  16  in the module, the PCB layer  16  may be replaced, eliminating the need to replace the upper and lower housing if such failure occurs. This also permits a single LED module to be replaced, or the PCB layer  16  of that module to be replaced, in the event of a failure, without having to replace an entire panel, resulting in significant savings in maintenance costs over time. 
         [0053]    Another embodiment of a back lit LED module, also connectable to form a mosaic of such modules, is shown in  FIGS. 11A-12B . As illustrated in those figures, an LED module  50  in accordance with a second aspect of the present invention is substantially the same in operation as the LED module  10  discussed above, but includes a differently shaped lower housing  51  and different manner of connection to other LED modules. In particular, in this embodiment, a larger connection opening/socket  52  is provided in the lower housing, with female portions  52   a . Female portions  52   a  are molded so as to mate with a connector  54  and male portions  54   a  of the connector  54 . As in the first embodiment, the connector  54  permits two LED modules  50  to be snapped together to form a mosaic of such LED modules. In this second embodiment, the connector is somewhat wider and in effect integrates two connectors of the first embodiment into one. As in the first embodiment, a PCB layer  16  (not visible in the figure), including LEDs  18 , is sandwiched between the upper housing, which is the same as in the first embodiment, and the lower housing  51 . An end cap  56 , shown in  FIG. 12A  can be used to cover an unused connection opening. As in the first embodiment, at least one of the LED modules in a mosaic formed by the LED modules needs to be connected to a power supply, such as by a power supply connector discussed above. 
         [0054]    Just as in the first embodiment, in the second embodiment the use of tiles  30  provides the ability to design a pleasing light display in the same manner as described above with reference to the first embodiment, and the identical description is not repeated here. Also, just as in the first embodiment, the LED modules can be connected together to form a mosaic of such modules, in this case using the larger connection opening  52  and connectors  54 . As in the first embodiment, at least on of the LED modules will be connected to the power supply unit, but the connectors will not be seen by providing, for example, a frame as shown above with reference to the first embodiment. Thus, in use, mosaics formed by tiling together LED modules of the second embodiment will look the same after assembly as mosaics formed by tiling together LED modules of the first embodiment. 
         [0055]    While the first and second embodiments discussed above use a back lit configuration, in which individual LEDs  18  mounted on a PCB  16  are located behind each aperture of the upper housing, in the third embodiment, light is produced by side lighting using LED/PCB strips mounted at two sides of the LED module. This embodiment is illustrated in  FIGS. 13A-14B . 
         [0056]    An exemplary side lit LED module  60  in accordance with the third embodiment of the present invention is formed from a lower housing  68 , PCB and LED strips  66 , an upper housing  69 , a light leading lens  70  and a transparent tile molding  62 . The lower housing  68  is preferably molded or otherwise formed to have openings  52  which can accept connectors, end caps, or power supply connectors, as shown, for example, above with reference to the first and second embodiments. The lower housing  68  preferably is formed so as to include a channel track  72 , which allows for mounting of the LED module  60 , and a mosaic formed by plural LED modules  60 , to, e.g., a wall or other surface. 
         [0057]    The lower housing  68  preferably includes slits  71  at two sides to guide the PCB and LED strips  66  and open slots  67  are provided in the upper housing  69  to allow the PCB and LED strips  66  to protrude to that the LEDs will be at the same level as the light leading lens  70  when the LED module  60  is assembled.  FIG. 13A  is a view of an assembled side lit LED module  60 .  FIG. 13B  is a view of the side lit embodiment of the LED module but without the transparent tile molding  62 , in order to show the direction of the light emitted from the LEDs. As can be seen from  FIG. 13B , the light is emitted in a sideways direction along the plane of the LED module, as shown by the arrows. The light so emitted is then guided and diffused by the light leading lens  70 , and, in conjunction with the transparent lens molding, is caused to be output out of the top of the LED module  60 .  FIG. 14A  is an underside view of the upper housing  69  showing the PCB and LED strips  66  inserted into the slots  67  of the upper housing  68 .  FIG. 14B  is an exploded parts view showing the abovementioned component elements of the side lit embodiment. 
         [0058]    Although the third embodiment is shown employing a lower housing having wider connection openings, similar to those shown with reference to the second embodiment discussed above, the lower housing in the side lit embodiment can also utilize connection openings and connectors as described above with regard to the first embodiment, as would be appreciated by one of skill in the art. In either case, the connection openings can provide electrical power and/or signals for the LEDs, including from the power supply unit discussed above, and from connectors attached to the connection openings. 
         [0059]    Preferably, in the side lit embodiment, the light leading lens  70  conducts light from the side mounted PCB and LED strips  66  in the direction of the arrows shown in  FIG. 13B . Transparent tile molding  62 , is formed so as to have raised portions  62   a , which permit application of tiles  64 . Just as in the first and second embodiments, the tiles  64  allow parts of the light to be blocked, colored, or otherwise modified, to provide a desired display effect for signage and the like. 
         [0060]    Although not shown in the figures illustrative of the second and third embodiments, a frame  40  is preferably used in mosaics formed in accordance with the second and third embodiments at the periphery of a mosaic of LED modules according to these embodiments in just the same manner shown in  FIGS. 9-10B . In these embodiments the frame has the same functions as in the first embodiment discussed above. 
         [0061]    The above embodiments advantageously permit multiple LED modules to be tiled together to form larger light emitting displays, for example, for forming signs. The ability to replace individual LED modules from such a mosaic, and the ability to use the snap on tiles to modify the light emitted from the LED modules, provides great flexibility in creating and modifying such displays without the need to manufacture a entire new display each time a new design or light pattern is required. 
         [0062]    Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.