Abstract:
A light distribution and control unit is provided which includes an array of light emitting diodes controlled by a microprocessor and a plurality of optical fibers. The light emitted from the array is injected into one end of the optical fibers and emitted from the other ends. The emitter ends are distributed through the interior of a limousine or hot tub to provide accent lighting. Different light patterns may be produced by the microprocessor.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of a prior filed, co-pending application Ser. No. 60/712,570, filed Aug. 30, 2005, entitled LIGHT DISTRIBUTION AND CONTROL UNIT.  
         [0002]     The present invention relates to lighting units and, more particularly, to a light distribution and control unit utilizing fiber optics to distribute light from an LED device source and a control unit to control the output of the LED device.  
     
    
     BACKGROUND  
       [0003]     Accent lighting for use in limousines and hot tubs, for example, is known in the art. In vehicles, a light box with two or more halogen lamps may be used as a source of accent lighting. The light from the halogen lamps is distributed within the vehicle using fiber optic strands terminated at the point of lighting. A color wheel, driven by a motor, may be included in the light box between the halogen lamps and the beginning of the fiber optic strands to vary the color of the light emanating from the fiber optic strand terminations. Halogen lamps are used because of their high light output.  
         [0004]     One problem with this light box is the halogen lamps produce a tremendous amount of heat, consume a lot of electricity and require periodic replacement. The light wheel drive motor consumes electricity and is subject to normal mechanical wear. The prior art light box is typically bulky which limits mounting options. Additionally, the color pattern output from the color wheel is limited.  
       SUMMARY  
       [0005]     The present invention includes a compact LED module with multiple color LEDs and a controller to vary the color and pattern of the LED module output. Fiber optic strands receive light directly from the LED module for distribution according to the application and installation.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is an illustration of the present invention installed in a limousine.  
         [0007]      FIG. 2  is a diagrammatic illustration of the present invention.  
         [0008]      FIG. 3  is an electrical schematic of the controller of the present invention.  
         [0009]      FIG. 4  is an electrical schematic of the LED driver of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0010]     Referring to  FIGS. 1 and 2 , a light distribution and control unit is generally indicated by reference numeral  10 . Light distribution and control unit  10  includes a housing  12 , a control circuit  14 , an LED array  16 , a heat sink  18 , and fiber optic strands  20 . The light distribution and control unit  10  may be mounted in the trunk of a limousine  22  or other vehicle, for example. Fiber optic strands  20  may be embedded in the headliner of the vehicle  22  to provide accent lighting or may provide lighting for a bar or in cabinets mounted in the vehicle, for example. Reference to a vehicle  22  is for illustrative purposes only and not as a limitation. Those skilled in the art will recognize other applications for the present invention such as decorative or accent lighting in hot tubs, for example.  
         [0011]     The light emitted from LED light array  16  may be focused by a lens  24  to inject the light into the ends of the fiber optic strands  20 . A reflector (not shown) may also be used to direct the light into the optic fiber strands  20 . Additionally, a transparent stop  26  may be used to space the ends of the fiber optic strands  20  away from the lens  24  or LED array  16  to protect them from the heat generated by the LED array  16 .  
         [0012]     Housing  12  may be metal or plastic. Heat sink  18  may be a block of aluminum sized to dissipate the heat created by the LED array  16 . LED array  16  is attached to the heat sink  18  with conductive epoxy or metal fasteners with a thermal grease in the joint to ensure efficient and adequate heat transfer.  
         [0013]     Referring to  FIGS. 3 and 4 , the control circuit  14  is divided into a power and controller circuit  30  and a current sourcing circuit  32 . Power and controller circuit  30  includes a power supply circuit  34 , a micro-controller circuit  36  and an LED current driver circuit  38 .  
         [0014]     The power supply circuit  34  provides power to the system. Power supply circuit  34  includes a power connector  40  and a voltage regulator  42 . Voltage regulator  42  receives 12-14 VDC power on line  44 . Capacitor  46  filters the input to minimize fluctuations in the input voltage to the voltage regulator  42 . Voltage regulator  52  provides a five VDC output on line  48  which is filtered by capacitor  50 .  
         [0015]     Power and input control signals are provided through connector  40  to microcontroller  52 . Microcontroller  52  is an eight-bit microcontroller with an A/D converter and EEPROM data memory such as a PIC12F675, available from Microchip, for example. It should be understood by one skilled in the art that any suitable microcontroller may be used.  
         [0016]     The microcontroller  52  may be programmed by connecting an in-circuit programmer (not shown) to connector  40  and downloading a compiled set of instructions to the microcontroller  52 .  
         [0017]     Based on the input voltage on lines  54  and  56  the microcontroller  52  varies the output on lines  58 ,  60  and  62  to adjust the duty cycle of the LEDs. Resistors R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are used to setup a voltage divider for inputs  54  and  56 .  
         [0018]     The LED current driver circuit  38  includes a darlington amplifier  63  which takes inputs on lines  48 ,  60  and  62  and outputs a 12 VDC pulse wave modulated signal on lines  64 ,  66 ,  68  which correspond to red, green and blue LEDs, respectively.  
         [0019]     The current sourcing circuit  32  includes a connector  70  to the LED current driver circuit  38 . Inputs on lines  72 ,  74  and  76  drive MOSfet transistors  78 ,  80  and  82  which are high current transistors capable of switching the low power signal from the microcontroller  52  to a high current sourcing output. Resistors  84 ,  86 ,  88 ,  90 ,  92  and  94  set the current to the LED array (not shown) connected to connector  96 .  
         [0020]     The LED array  16  (See  FIG. 2 ) may be configured with seven cavities, each populated with LEDs. A RGB light engine such as the Lamina BL-2000 RGB, for example, may be used which contains a multiple red, green and blue LED die in each cavity for optimal color uniformity and high luminous intensity. The LED array has independent color control for dynamic or preset display of colors. Through additive color mixing, there is a complete control of the various colors and white light which can be output.  
         [0021]     For an input of 0 volts on line  98 , microcontroller  52  outputs a varying signal on lines  58 ,  60  and  62  that causes the LED array  16  to output a light which slowly fades from one color to the next at a predetermined rate. For an input of 6.7 VDC, the LED array outputs a steady white light. For an input of 10 VDC, the LED array fades from one color to the next at a filter rate to provide a twinkling effect. Finally, at an input voltage of 13.5 VDC, the LED array fades quickly from one color to the next at a predetermined rate.  
         [0022]     It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto, except in so far as such limitations are included in the following claims and allowable equivalents thereof.