Abstract:
A tail light assembly for a motorcycle. The tail light assembly includes a housing configured to receive a circuit. The circuit includes a light emitting diode (LED) and a controller. The LED provides tail, stop, and turn visual indications associated with the motorcycle. The controller supplies a voltage to the LED to light the LED to a brightness based on the signals received. In addition, the controller also sinks a current of a magnitude substantially equivalent to a magnitude of current drawn by an incandescent lamp when providing a visual turn indication.

Description:
BACKGROUND 
       [0001]    Motorcycles often include several sets of lights which serve to make a motorcycle more visible to other drivers, as well as to signal the intention of the motorcycle&#39;s rider (e.g., via turn signals). Often, lights are mounted near the front of a motorcycle so that they are visible to motorists and others in front of the motorcycle. In addition, lights are often mounted near the rear of a motorcycle so that the motorcycle&#39;s rider is clearly visible from behind. 
         [0002]    Motorcycles generally include a headlight and left and right turn signal lights mounted near the front. Motorcycles also generally include a tail/stop light, and left and right turn signal lights near the rear. The lights generally include an incandescent bulb and can be controlled by an electronic control module. 
       SUMMARY 
       [0003]    In one embodiment, the invention provides a tail light assembly for a motorcycle. The tail light assembly includes a circuit and a housing configured to receive the circuit. The circuit includes a first light emitting diode (“LED”) configured to provide at least a visual turn indication associated with the motorcycle, and a controller having at least one controller input and at least one controller output. The at least one controller output is configured to supply current to the first LED. The tail light assembly is configured to draw current having at least a first current magnitude when an input signal corresponding to the visual turn indication is received by the controller, wherein the first current magnitude is substantially equivalent to a magnitude of current drawn by a second tail light assembly employing an incandescent lamp to provide a visual turn indication. 
         [0004]    In another embodiment, the invention provides a method of operating a tail light assembly including a first LED, a controller having at least one controller input and at least one controller output, and a housing. The method comprises receiving an input signal corresponding to a visual turn indication on the at least one controller input, supplying a current to the LED from the at least one controller output, providing the visual turn indication, and drawing, by the tail light assembly, a current having a first current magnitude, the first current magnitude substantially equivalent to a magnitude of current drawn by a second tail light assembly employing an incandescent lamp to provide the visual turn indication. 
         [0005]    In another embodiment, the invention provides a motorcycle including an engine, a plurality of wheels, and a lighting and indication system. The lighting and indication system includes at least one headlight, a plurality of forward turn signals, and a plurality of tail light assemblies. Each of the tail light assemblies includes a circuit having a first LED configured to provide at least a visual turn indication associated with the motorcycle, and a controller having at least one controller input and at least one controller output, the at least one controller output configured to supply current to the first LED. Each of the tail light assemblies also includes a housing configured to receive the circuit. Each of the tail light assemblies is configured to draw current having at least a first current magnitude when an input signal corresponding to the visual turn indication is received by its respective controller. The first current magnitude is substantially equivalent to a magnitude of current drawn by a second tail light assembly employing an incandescent lamp to provide a visual turn indication. 
         [0006]    Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  illustrates a perspective view of a motorcycle according to an embodiment of the invention. 
           [0008]      FIG. 2  illustrates a rear view of a motorcycle according to an embodiment of the invention. 
           [0009]      FIG. 3  illustrates a top view of a motorcycle according to an embodiment of the invention. 
           [0010]      FIG. 4  illustrates a schematic diagram of an embodiment of a lighting system according to an embodiment of the invention. 
           [0011]      FIG. 5  illustrates a schematic diagram of a plurality of switches and inputs to an electronic control module of the lighting system of  FIG. 4 . 
           [0012]      FIG. 6A  illustrates a front view of a tail/stop/turn light according to an embodiment of the invention. 
           [0013]      FIG. 6B  illustrates a side view of a tail/stop/turn light according to an embodiment of the invention. 
           [0014]      FIG. 6C  illustrates a top view of a tail/stop/turn light according to an embodiment of the invention. 
           [0015]      FIG. 7  illustrates an exploded view of the tail/stop/turn light of  FIGS. 6A-6C  according to an embodiment of the invention. 
           [0016]      FIG. 8  illustrates a circuit for a tail/stop/turn light according to an embodiment of the invention. 
           [0017]      FIG. 9  is a flow chart of an operational process of the tail/stop/turn light of  FIG. 8  according to an embodiment of the invention. 
           [0018]      FIG. 10  illustrates a circuit diagram for a turn signal circuit employing an LED and an incandescent light according to an embodiment of the invention. 
           [0019]      FIG. 11  illustrates a circuit diagram for a turn signal circuit employing an LED and a current sinking resistor to mimic the current draw of an incandescent light according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
         [0021]      FIGS. 1-3  illustrate perspective, rear, and top views of an exemplary motorcycle  100 . The motorcycle  100  includes a drive assembly  105 , a frame  110 , a front fork assembly  115 , a swing arm or rear fork assembly  120 , a front wheel  125 , a rear wheel  130 , a seat  135 , and a fuel tank  140 . The frame  110  supports the drive assembly  105 , the front fork assembly  115 , the rear fork assembly  120 , the seat  135 , and the fuel tank  140 . The front fork assembly  115  is pivotally supported at a front end of the motorcycle  100  and supports the front wheel  125 . The front fork assembly  115  includes a pair of handlebars  145  for steering the motorcycle  100 . The rear fork assembly  130  is coupled to the frame  110  at a rear end of the motorcycle  100  and rotatably supports the rear wheel  130 . The seat  135  is coupled to the frame  110  and is configured for supporting a rider. The fuel tank  140  is supported by the frame  110  and provides fuel to the drive assembly  105 . 
         [0022]    The drive assembly  105  includes an engine  150  and a transmission  155 . The engine  150  and the transmission  155  comprise distinct, independent components of the drive assembly  105 . The engine  150  includes an output shaft (not shown), such as a crankshaft, which includes a primary drive sprocket (not shown) for driving a primary chain (not shown) in a conventional manner to power the transmission  155 . 
         [0023]    The motorcycle  100  also includes a headlight  160 , a front left turn signal  165 , a front right turn signal  170 , a rear left tail/stop/turn light  175 , and a rear right tail/stop/turn light  180 . 
         [0024]    A conventional lighting system for a motorcycle includes a headlight, a front right turn light, a front left turn light, a tail/stop light, and separate left and right rear turn lights. The lighting system of an embodiment of the invention combines the tail/stop light with the rear turn lights, resulting in a right and left tail/stop/turn light assembly. 
         [0025]      FIG. 4  illustrates a schematic diagram of an embodiment of a lighting and indication system  200  for a motorcycle. The lighting system  200  includes an electronic control module (“ECM”)  205 , a battery  210  (e.g., 12 vdc), a headlight  215 , a front left turn light  220 , a front right turn light  225 , a left tail/stop/turn light  230 , a right tail/stop/turn light  235 , and a plurality of switches  240 . 
         [0026]    The battery  210  has a positive terminal  245  connected to a power input  250  of the ECM  205  and a negative terminal  255  connected to a ground on the motorcycle. 
         [0027]      FIG. 5  illustrates the connections of the plurality of switches  240  to the ECM  205  for the embodiment shown. The plurality of switches  240  include a front brake switch  260 , a rear brake switch  265 , an ignition switch  270 , a right turn switch  275 , and a left turn switch  280 . A first terminal of each of the plurality of switches  240  is connected to a power signal (e.g., +12 vdc from the positive terminal  245  of the battery  210 ). A second terminal of each of the plurality of switches  240  is connected to a separate input of the ECM  205 . In particular, a front brake switch second terminal  300  is connected to a first brake input  302  of the ECM  205 . A rear brake switch second terminal  304  is connected to a second brake input  306  of the ECM  205 . In some embodiments, the first and second brake inputs  302  and  306  of the ECM  205  can be the same input. An ignition switch second terminal  308  is connected to an ignition input  310  of the ECM  205 . A right turn switch second terminal  312  is connected to a right turn input  314  of the ECM  205 . A left turn switch second terminal  316  is connected to a left turn input  318  of the ECM  205 . 
         [0028]    Referring back to  FIG. 4 , a headlight output  320  of the ECM  205  is connected to an input  322  of the headlight  215 . A left turn output  324  of the ECM  205  is connected to an input  326  of the front left turn light  220  and a turn input  328  of the left tail/stop/turn light  230 . A right turn output  330  of the ECM  205  is connected to an input  332  of the front right turn light  225  and a turn input  328  of the right tail/stop/turn light  235 . A tail output  336  of the ECM  205  is connected to a tail input  338  of the left tail/stop/turn light  230  and a tail input  338  of the right tail/stop/turn light  235 . A stop output  342  of the ECM  205  is connected to a stop input  344  of the left and right tail/stop/turn lights  230  and  235 . 
         [0029]    When the ignition switch  270  closes (e.g., when a rider starts an engine), a signal (e.g., +12 vdc) is provided to the ignition input  310  of the ECM  205 . The ECM  205  detects the signal on its ignition input  310  and provides a signal (e.g., +12 vdc) to its headlight output  320 , thereby applying the signal to the input  322  of the headlight  215 . The ECM  205  also provides a signal (e.g., +12 vdc) to its tail output  336 , thereby applying the signal to the tail input  338  of the left tail/stop/turn light  230  and the right tail/stop/turn light  235 . 
         [0030]    When the front brake switch  260  closes (e.g., when a handlebar brake is engaged by a rider), a signal (e.g., +12 vdc) is provided to the first brake input  302  of the ECM  205 . The ECM  205  detects the signal on its first brake input  302  and provides a signal (e.g., +12 vdc) to its stop output  342 , thereby applying the signal to the stop input  344  of the left tail/stop/turn light  230  and the right tail/stop/turn light  235 . 
         [0031]    When the rear brake switch  265  closes (e.g., when a foot brake is engaged by a rider), a signal (e.g., +12 vdc) is provided to the second brake input  306  of the ECM  205 . The ECM  205  detects the signal on its second brake input  306  and provides a signal (e.g., +12 vdc) to its stop output  342 , thereby applying the signal to the stop input  344  of the left tail/stop/turn light  230  and the right tail/stop/turn light  235 . 
         [0032]    When the right turn switch  275  closes (e.g., when a rider engages the right turn switch  275 ), a signal (e.g., +12 vdc) is provided to the right turn input  314  of the ECM  205 . The ECM  205  detects the signal on its right turn input  314  and provides a signal (e.g., +12 vdc) to its right turn output  330 , thereby applying the signal to the input  332  of the front right turn light  225  and the turn input  328  of the right tail/stop/turn light  235 . 
         [0033]    When the left turn switch  280  closes (e.g., when a rider engages the left turn switch  280 ), a signal (e.g., +12 vdc) is provided to the left turn input  318  of the ECM  205 . The ECM  205  detects the signal on its left turn input  318  and provides a signal (e.g., +12 vdc) to its left turn output  324 , thereby applying the signal to the input  326  of the front left turn light  220  and the turn input  328  of the left tail/stop/turn light  230 . 
         [0034]      FIGS. 6A-6C  illustrate front, side, and top views, respectively, of an embodiment of a tail/stop/turn light assembly  450 .  FIG. 7  is an exploded view of an embodiment of the tail/stop/turn light assembly  450 . The tail/stop/turn light assembly  450  includes a housing  455 , a circuit board  460 , an LED  465 , a reflector  470 , a seal  475 , and a lens  480 . In some embodiments, the housing  455  has a generally rounded conical (i.e., bullet) shape. The housing  455  is configured to receive and mount the circuit board  460 , the reflector  470 , the seal  475 , and the lens  480 . The shape of the housing  455  can enable the tail/stop/turn light assembly  450  to have relatively low wind resistance when mounted on a motorcycle. The housing  455  can be constructed of any suitable material including injection molded plastic and chromed steel. In some embodiments, the lens  480  is about 2.38 inches in diameter and the combined length of the housing  455  and lens  480  is about 3.28 inches. 
         [0035]    In the illustrated embodiment, the lens  480  is formed by injection molding a translucent thermoplastic (e.g., polyethylene) such that light is allowed to pass through the lens  480 . The lens  480  can be any color. However, to meet regulations applicable to a motorcycle tail/stop/turn light assembly (e.g., Federal Motor Vehicle Safety Standard 571.108), the lens  480  is either red (for use with any color LED  465 , e.g., white) or clear for use with a red LED  465 . The lens  480  can include external threads for screwing onto internal threads in the housing  455 . 
         [0036]    The seal  475  can be positioned between the housing  455  and the lens  480 . When the lens  480  is screwed into the housing  455 , the seal  475  can form a water-tight seal and prevent water and other debris from entering the housing  455 . 
         [0037]    The reflector  470  includes a plurality of multifaceted reflecting surfaces designed to reflect and evenly distribute light from the LED  465  out through the lens  480 . 
         [0038]    A cable  485  including a plurality of wires  490  (e.g., four) links the tail/stop/turn light assembly  450  to an ECM on a motorcycle. 
         [0039]      FIG. 8  illustrates a block diagram of a tail/stop/turn light  500  according to an embodiment of the invention. A control circuit  505  receives three input signals: a stop input  510 , a tail input  515 , and a turn input  520 . The control circuit  505  also has a connection to ground. The control circuit  505  drives the LED  525  based on the combination of signals received on the three inputs—stop  510 , tail  515 , and turn 520. 
         [0040]    The control circuit  505  can provide a first current (e.g., 0.02 amps) to the LED  525  to light the LED  525  at a first brightness. The control circuit  505  can also provide a second current (e.g., 0.2 amps) to light the LED  525  at a second brightness that is substantially brighter than the first brightness. 
         [0041]    In some embodiments, the control circuit  505  can provide additional currents to the LED  525  to produce additional brightness levels (e.g., to provide one brightness for daytime operation and another brightness for nighttime operation). 
         [0042]      FIG. 9  illustrates a flow chart of an operational process of the tail/stop/turn light  500  of  FIG. 8  according to an embodiment of the invention. The control circuit  505  of the tail/stop/turn light  500  determines, at block  600 , whether the control circuit  505  is receiving a signal on its tail input  515 . The ECM provides the tail/stop/turn light  500  with a signal at the tail input  515  whenever the ignition switch of the motorcycle is turned on. If a signal is received at the tail input  515 , the tail/stop/turn light  500  illuminates the LED  525  to the first brightness (block  605 ). If a signal is not received on the tail input  515 , the control circuit  505  skips block  605 . 
         [0043]    Next, the control circuit  505  determines, at block  610 , whether it is receiving a signal on its stop input  510 . The ECM provides the tail/stop/turn light  500  with a signal at the stop input  510  whenever the front or rear brake switch of the motorcycle is closed. If a signal is received at the stop input  510 , the tail/stop/turn light  500  illuminates the LED  525  to the second brightness (block  615 ). If a signal is not received on the stop input  510 , the control circuit  505  skips block  615 . 
         [0044]    Next, the control circuit  505  determines, at block  620 , whether it is receiving a signal on its turn input  520 . If a signal is not received on the turn input  520 , the control circuit  505  loops back to block  600 . If a signal is received on the turn input  520 , the control circuit  505  illuminates the LED  525  to the first brightness (block  625 ). The control circuit  505  then delays for a period of time (e.g., 0.5 seconds) (block  630 ) and then illuminates the LED  525  to the second brightness (block  635 ). The control circuit  505  then delays for a second time period (block  640 ) and continues at block  620  to check if a signal is received on the turn input  520 . In some embodiments, the first and second time periods are substantially equal. 
         [0045]      FIG. 10  illustrates an embodiment of a circuit  650  for a front and back turn signal. An ECM  655  is connected to +12 vdc (e.g., the battery  210 ) and ground. A turn switch  660  is connected to +12 vdc on its first terminal and is connected to a turn input  665  of the ECM  655 . A turn output  670  of the ECM  655  is connected to a front turn light  675  and a rear turn light  680  which are both also connected to ground. The front turn light  675  is an incandescent lamp and the rear turn light  680  is an LED. A typical incandescent lamp draws about 2 amps when provided with a 12 vdc signal. An LED, however, draws substantially less current than the incandescent lamp (e.g., 0.2 amps). Therefore, the total circuit  650  draws about 2.2 amps when the switch  660  is closed. An ECM designed to monitor current in a turn signal circuit using incandescent lights for both the front and rear turn signals expects the circuit to draw approximately 4 amps (2 amps for the front turn light plus 2 amps for the rear turn light). Since the circuit of  FIG. 10  draws only 2.2 amps, a standard ECM would determine that one of the lights is burned out and provide an indication to the operator that a light is burned out even though both lights are functioning properly. 
         [0046]      FIG. 11  illustrates the turn signal circuit  650  of  FIG. 10  configured to draw enough current such that an ECM does not falsely detect a burned out lamp. A power resistor  710  is provided in parallel with the front turn light  675  (i.e., incandescent light) and the rear turn light  680  (i.e., LED). When switch  660  is closed, the resistance of the incandescent lamp, the LED, and the power resistor  710  combine to approximate the resistance of two incandescent lamps and to draw about 4 amps. In some embodiments, the power resistor can use a housing of a tail/stop/turn light as a heat sink. 
         [0047]    In some embodiments of an LED tail/stop/turn light assembly, the control circuit  505  ( FIG. 8 ) receives the stop  510 , tail  515 , and turn 520 input signals from the ECM. The control circuit  505  illuminates the LED  525  to the first or second brightness as shown in Table 1 below. The control circuit  505  also sinks enough current such that the ECM does not falsely detect a burned out light. 
         [0048]    When the motorcycle is turned off (i.e., the ignition switch is open), no signal is applied to the tail input of the control circuit  505 . No voltage is available to the LED  525  and the LED  525  is off. When the motor is turned on (i.e., the ignition switch is closed), there is a signal at the tail input  515  of the control circuit  505 . There are four possible combinations of the stop input  510  and the turn input  520  when the ignition is turned on. In the first scenario, there is no signal at either the stop input  510  or the turn input  520 . The control circuit  505  drives the LED  525  with 0.02 amps, illuminating the LED  525  at a low brightness. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Controller Inputs 
                   
               
             
          
           
               
                 Tail 
                   
                   
                 Voltage* 
                 Current** 
                 Power** 
                 LED 
               
               
                 (ignition) 
                 Stop 
                 Turn 
                 (vdc) 
                 (amps) 
                 (watts) 
                 Brightness 
               
               
                   
               
             
          
           
               
                 0 
                 x 
                 x 
                 0 
                 0 
                 0 
                 Off 
               
               
                 1 
                 0 
                 0 
                 13.5 
                 0.02 
                 0.27 
                 Low 
               
               
                 1 
                 1 
                 0 
                 13.5 
                 0.2 
                 2.7 
                 High 
               
               
                 1 
                 0 
                 1 
                 13.5 
                 1.55 
                 21 
                 Cycle 
               
               
                 1 
                 1 
                 1 
                 13.5 
                 1.55 
                 21 
                 Cycle 
               
               
                   
               
               
                 *Provided by the ECM to the controller. 
               
               
                 **Drawn from the ECM by the controller. 
               
             
          
         
       
     
         [0049]    In the second scenario, a signal is applied to both the tail input  515  and the stop input  510 , but there is no signal applied to the turn input  520 . The control circuit  505  drives the LED  525  with 0.2 amps of current, illuminating the LED  525  with a high brightness. 
         [0050]    In the third scenario, a signal is applied to both the tail input  515  and the turn input  520 , but there is no signal applied to the stop input  510 . The control circuit  505  cycles driving the LED  525  between the low and the high brightness to flash the LED  525 . The control circuit  505  also draws 1.55 amps from the ECM to mimic the current draw of an incandescent light. 
         [0051]    In the fourth scenario, a signal is applied to the tail input  515 , the stop input  510 , and the turn input  520 . The control circuit  505  cycles driving the LED  525  between the low and the high brightness to flash the LED  525 . The control circuit  505  also draws 1.55 amps from the ECM to mimic the current draw of an incandescent light. 
         [0052]    It is to be appreciated that the values of the electrical characteristics, the circuit configurations, the logic levels, etc. described herein (e.g., in Table 1) are exemplary and could be modified for particular implementations. 
         [0053]    In various embodiments herein, an LED tail/stop/turn light assembly mimics the operation of a tail/stop/turn light assembly employing an incandescent light or the operation of a standard tail/stop light assembly and a separate turn light assembly both employing incandescent lights. Embodiments herein can be retrofit onto an existing motorcycle or used on a new motorcycle, without making modifications to the existing onboard electrical system and components. For instance, an existing ECM can be used with the LED tail/stop/turn light assembly without modification. Since LEDs generally do not burn out, a standard ECM used with the LED tail/stop/turn light assembly for the rear lights can determine if a front turn incandescent light is burned out and can provide an indication of such component failure to a rider. 
         [0054]    In some embodiments, a tail/stop/turn light assembly can use more than one LED. For example, an amber LED can be used as a turn indication and a red LED can be used for the tail and stop indications. Further, one red LED can be used for the tail indication and a different or multiple red LEDs can be used for the stop indication. In addition, LED turn light assemblies can be used for the front turn indicators. 
         [0055]    Thus, the invention provides, among other things, an LED tail/stop/turn light that can be used with a standard ECM. Various features and advantages of the invention are set forth in the following claims.