Abstract:
In the present invention, an inner lens of a turn signal lamp is provided with: a lens cut part that inhibits the transmission of light travelling, when seen in a front view, linearly from a substrate toward an outer lens; a projection part that projects toward an LED; and an eave part that extends from the base end side of the projection part inwardly in the vehicle width direction. A harness that is electrically connected with the LED is connected to the substrate through a partial space that is surrounded by the substrate, the projection part, and the eave part.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a vehicular lighting device (lighting device for vehicle) that employs light emitting diodes as a light source. 
       BACKGROUND ART 
       [0002]    Heretofore, with a lighting device that employs light emitting diodes, in order to enhance the external appearance (aesthetic appearance) thereof, a structure has been provided in which wires (harnesses) for supplying power to the light emitting diodes are hidden from view. 
         [0003]    For example, in Japanese Patent No. 4437952, a tail lamp structure is disclosed in which light emitting diodes are applied as a light source. As shown in FIG. 8 of Japanese Patent No. 4437952, a light emitting diode board (board) on which light emitting diodes are mounted is attached to a housing (base), and a harness, which is connected to the board, extends from a lower side of the base. In this case, a configuration is provided so that the harness cannot be seen from the exterior, by means of a mud cover that is laid over the harness underneath a lens. 
       SUMMARY OF INVENTION 
       [0004]    However, when a structure is provided as in Japanese Patent No. 4437952, in which a vehicle cover, such as the aforementioned mud cover, is used to cover a harness that extends from the board, the light emitting area of the lighting device is reduced. On the other hand, in the case that the harness is covered by a vehicle cover while attempting to preserve the light emitting area of the lighting device, a structure may be considered in which the board on which the light emitting diodes are mounted is made larger, whereas the harness is connected at a position separated a given distance from the light emitting diodes, and then is covered by the vehicle cover. However, in this case, there is a possibility for other problems to occur in that, due to the fact that the board is made larger in size, production costs increase, and the lighting device is made larger in scale, which contravenes the goal of enhancing the external appearance of the lighting device. 
         [0005]    The present invention has been made taking into consideration the aforementioned situation, and has the object of providing a vehicular lighting device, which is capable of enhancing the external appearance of the lighting device by concealing the visibility of a harness connected to a light emitting diode board with a simple structure, while also sufficiently preserving the light emitting area when light is irradiated therefrom. 
         [0006]    According to claim  1  of the present invention, there is provided a vehicular lighting device comprising a base, an outer lens attached to a front part of the base, a board having a light emitting diode mounted thereon and which is accommodated inside an inner space formed by the base and the outer lens, and an inner lens arranged between the outer lens and the board. The inner lens comprises a lens cut region that diffuses light from the board toward the outer lens as viewed from the front, a protruding portion disposed at a position facing the light emitting diode and which projects toward the light emitting diode, and a roof extending from a base end side of the protruding portion along a transverse inward direction of the vehicle. A partial space is formed in an inner space and surrounded by the board, the protruding portion, and the roof, and a harness, which is electrically connected to the light emitting diode, is connected to the board through the partial space. 
         [0007]    According to claim  2  of the present invention, in the lighting device according to claim  1 , the roof is formed integrally with the protruding portion, and is formed in a flat shape having a wall thickness thinner than that of the protruding portion. 
         [0008]    According to claim  3  of the present invention, in the lighting device according to claim  1 , the base includes a hole therein that communicates from an outer surface thereof to the partial space, a retaining member that retains the harness is installed in the hole, and the roof extends to an end of the retaining member which projects into the partial space. 
         [0009]    According to claim  4  of the present invention, in the lighting device according to claim  1 , at least a part of an area of connection between the board and the harness overlaps with the protruding portion as viewed from the front. 
         [0010]    According to claim  5  of the present invention, in the lighting device according to claim  1 , the inner lens is mounted on the base. If an imaginary line is defined that extends in a transverse direction of the vehicle through a mounting portion of the base and the inner lens, the inner lens is arranged such that the base end side of the protruding portion is positioned nearer the outer lens in relation to the imaginary line, and an apex side of the protruding portion is positioned nearer the board in relation to the imaginary line. 
         [0011]    According to claim  6  of the present invention, in the lighting device according to claim  5 , the base includes a flat surface that matches substantially with a direction of extension of the imaginary line, and the outer lens and the inner lens are mounted by welding on the flat surface, and wall members are erected on the flat surface between a welded part of the outer lens and a welded part of the inner lens. 
         [0012]    According to claim  7  of the present invention, in the lighting device according to claim  6 , support members are formed on an outer peripheral surface of the base, which serve to support the base when the outer lens and the inner lens are welded thereon. 
         [0013]    According to claim  8  of the present invention, in the lighting device according to claim  1 , a plurality of board welding parts, which are welded onto the base, are disposed on the board. Further, the light emitting diode comprises a plurality of light emitting diodes, the board being installed such that a predetermined distance is defined between terminals of each of the plurality of light emitting diodes and the plurality of board welding parts. 
         [0014]    In the invention according to claim  1 , by connecting the harness, which is electrically connected to the light emitting diode, to the board through the partial space, which is surrounded by the roof and protruding portion of the inner lens having the lens cut region, for example, even though the harness is not covered by another member such as a vehicle body cover or the like, as viewed from the front, visibility of the harness from the exterior can be made difficult due to the existence of the roof. Further, because the protruding portion, which projects toward the light emitting diode, is formed more outwardly in the transverse direction of the vehicle in relation to the roof, in the event that the lighting device is viewed from a diagonally outward side in the transverse direction of the vehicle, the harness can be made even less visible due to the thickness of the protruding portion and the presence of the lens cut region. More specifically, without applying another member such as a vehicle body cover or the like, since the harness can be concealed from view by the inner lens, the outer appearance of the lighting device can be enhanced, and a sufficient light emitting area can be assured. Further, since it is possible to connect the harness to the board at a position near the light emitting diode, the board can be made small in size, and the lighting device as a whole can be reduced in scale. 
         [0015]    In the invention according to claim  2 , by forming the roof in a flat shape and with a wall thickness that is less than that of the protruding portion, the partial space surrounded by the protruding portion, the roof, and the board can be widened, and the harness can easily be arranged or laid out therein. Further, by forming the roof and the protruding portion integrally with each other, fewer component parts are used, assembly can be facilitated, and production costs can be reduced. 
         [0016]    In the invention according to claim  3 , by having the roof extend to an end of the retaining member which projects into the partial space, the harness, which extends from the end of the retaining member into the partial space, can be covered by the roof, and thus the harness can be made less visible. 
         [0017]    In the invention according to claim  4 , by making the area of connection between the board and the harness overlap with the protruding portion as viewed from the front, the connected portion can be hidden by the protruding portion, and can thereby make the harness even less easily visible from the exterior. 
         [0018]    In the invention according to claim  5 , by arranging the inner lens such that the base end side of the protruding portion is positioned nearer the outer lens in relation to the imaginary line, and such that the apex side of the protruding portion is positioned nearer the board in relation to the imaginary line, the inner lens can be disposed so as to enwrap and cover the opening of the base, whereby the harness can be more fully concealed by the roof and the protruding portion, and the harness is more difficult to be seen when the lighting device is viewed diagonally from an outer transverse side of the vehicle. 
         [0019]    In the invention according to claim  6 , since the outer lens and the inner lens are welded onto the same flat surface, the outer lens and the inner lens can easily be welded without large variations in the height position of the welding surface. Further, by erecting the wall members on the flat surface between welded portions of the outer lens and the inner lens, during welding of the outer lens and the inner lens, penetration of welding debris at the mutual welded portions can be prevented. 
         [0020]    In the invention according to claim  7 , by forming the support members for supporting the base, when a welding operation is carried out on the outer lens and the inner lens, such welding can be preformed in a condition where the base is supported stably, for example, by a jig. Owing thereto, since shaking of the base caused by vibration welding or the like can be reduced, working efficiency can be improved when assembling the winker lamp. 
         [0021]    In the invention according to claim  8 , by welding the board and the base, only a few number of screws are required for fixing the board, and therefore, the number of component parts can be reduced. Further, since it is unnecessary to provide multiple screw holes in the base, the base can be made smaller in size. Furthermore, as a result of the board being installed such that a predetermined distance is defined between terminals of each of the plurality of light emitting diodes and the plurality of board welding parts, welding debris does not become adhered to the terminals of the light emitting diodes due to welding of the board and the base. 
         [0022]    The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]      FIG. 1  is a schematic side elevational view of a saddle-type motorcycle incorporating a vehicular lighting device according to an embodiment of the present invention; 
           [0024]      FIG. 2  is an enlarged fragmentary front elevational view of a front upper portion of the motorcycle shown in  FIG. 1 ; 
           [0025]      FIG. 3  is a view of a portion of the motorcycle shown in  FIG. 1 , as viewed in a direction indicated by the arrow A in  FIG. 1 ; 
           [0026]      FIG. 4  is a table showing turned-on and turned-off states of an ON-indicator and an OFF-indicator of a TCS (Traction Control System) shown in  FIG. 3 ; 
           [0027]      FIG. 5  is an enlarged front elevational view of a winker lamp shown in  FIG. 2 ; 
           [0028]      FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 5 ; 
           [0029]      FIG. 7  is a cross-sectional view taken along line VII-VII of  FIG. 5 ; 
           [0030]      FIG. 8  is a front elevational view showing a state in which an outer lens of the winker lamp of  FIG. 5  is detached therefrom; 
           [0031]      FIG. 9  is a perspective view showing the winker lamp of  FIG. 8 ; 
           [0032]      FIG. 10  is a front elevational view showing a state in which an inner lens of the winker lamp of  FIG. 8  is detached therefrom; 
           [0033]      FIG. 11  is a rear view of the winker lamp of  FIG. 5 ; and 
           [0034]      FIG. 12  is a schematic block diagram of a circuit arrangement of a winker lamp lighting control system. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0035]    A vehicular lighting control device according to a preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 
         [0036]      FIG. 1  is a schematic side elevational view of a saddle-type motorcycle (hereinafter also referred to as a “motorcycle”)  12 , which incorporates therein a vehicular lighting control device (winker lamp)  10  according to an embodiment of the present invention. The present invention will hereinafter be described in detail below as applied to a saddle-type motorcycle. However, the principles of the present invention are not limited to a saddle-type motorcycle, but also are applicable to any of various other land vehicles, including other types of powered two-wheeled vehicles, motor-assisted bicycles, and powered four-wheeled vehicles. For easier understanding of the present invention, forward, rearward, upward, and downward directions will be described with respect to the directions indicated by the arrows in  FIG. 1 . Leftward and rightward directions (see the leftward and rightward directions indicated by the arrows in  FIG. 2 ) will be described with respect to directions as viewed by the rider seated on the saddle-type motorcycle  12 . 
         [0037]    As shown in  FIG. 1 , the motorcycle  12  includes a vehicle frame  14  as a vehicle body, a pair of left and right front fork members  18  rotatably supported by a head pipe  16  on the front end of the vehicle frame  14 , a front wheel (steerable wheel)  20  mounted on the front fork members  18 , an engine  22  supported on the vehicle frame  14 , which serves as a drive source for the motorcycle  12 , a swing arm  26  swingably supported on a lower pivot  24  of the vehicle frame  14 , and a rear wheel (drive wheel)  28  mounted on the rear end of the swing arm  26 . 
         [0038]    The vehicle frame  14  comprises a highly rigid tube frame, which is cast of aluminum. The vehicle frame  14  includes a pair of left and right main frames  30  that branch leftward and rightward from the head pipe  16 , and which extend obliquely rearward and downward therefrom, the pivot  24  joined to rear portions of the main frames  30  and extending downwardly therefrom, and a pair of left and right seat frames  32  mounted on a rear portion of the main frames  30  and extending obliquely rearward and upwardly therefrom. The vehicle frame  14  comprises a structure constructed from a reduced number of frame components and which is capable of supporting mechanisms within the vehicle body. 
         [0039]    The front fork members  18  extend substantially vertically on a front portion of the vehicle body. A top bridge  34  (see  FIG. 3 ) is mounted on upper portions of the front fork members  18 . A headlight  36  for illuminating an area in front of the vehicle body is disposed on upper portions of the front fork members  18 . A handle assembly  38  for steering the front wheel  20  is mounted on the top bridge  34 . The handle assembly  38  includes a pair of left and right handlebars  39  that extend outward symmetrically to the left and right transversely to the vehicle body, and grips  38   a  mounted respectively on left and right ends of the handlebars  39 . A pair of left and right rearview mirrors  40  are mounted on respective portions of the handlebars  39 . 
         [0040]    The front wheel  20  is rotatably supported on lower ends of the front fork members  18 . A brake device  20   a  in the form of a disk brake is mounted on one side of the front wheel  20 . The front wheel  20  has an upper portion covered with a front fender  42 , which is attached to lower portions of the front fork members  18  above the front wheel  20 . 
         [0041]    The engine  22  comprises a water-cooled, four-stroke V-shaped four-cylinder engine. The engine  22  includes a crankcase  44  disposed on a lower portion thereof, a front cylinder  46  extending obliquely forward and upwardly from the crankcase  44 , and a rear cylinder  48  extending in a rearward direction obliquely from the crankcase  44  behind the front cylinder  46 . The engine  22  has an intermediate portion disposed between the front cylinder  46  and the rear cylinder  48 , which is fixed to and supported by the main frames  30 , and a portion disposed behind the rear cylinder  48 , which is fixed to and supported by the pivot  24 , so that the engine  22  is disposed in a fixed posture with respect to the main frames  30 . 
         [0042]    Each of the front cylinder  46  and the rear cylinder  48  houses therein an ignition plug for igniting an air-fuel mixture therein, and a piston for compressing the air-fuel mixture, neither of which is shown. A crankshaft and an engine output shaft (not shown), which are operatively connected to the pistons by connecting rods, are rotatably supported in the crankcase  44 . The engine  22  is combined with a dual clutch transmission, which includes two clutches that can be switched into operation for allowing the motorcycle  12  to travel selectively in two travel modes, e.g., an automatic mode and a manual mode. When the engine  22  is in operation, rotational drive power is produced, which is transmitted by a drive shaft (not shown) extending rearwardly from the crankcase  44  to the rear wheel  28 . A radiator  50  for radiating heat from the engine  22  is disposed in front of the front cylinder  46 . A fuel tank  52  and an intake unit  54  are disposed above the engine  22 . The intake unit  54  includes a throttle body  56  connected to respective inner upper portions of the front cylinder  46  and the rear cylinder  48 , and an air cleaner  58  connected to an upstream end of the throttle body  56  by a non-illustrated intake pipe. The throttle body  56  incorporates a TBW (Throttle By Wire) system for changing the opening of a throttle valve disposed therein via an actuator. The intake unit  54  introduces air through the air cleaner  58 , which removes dust and dirt and injects cleaned air together with fuel from the throttle body  56  into the front cylinder  46  and the rear cylinder  48 . 
         [0043]    The engine  22  is disposed above an exhaust assembly  60 . The exhaust assembly  60  includes exhaust tubes  62  extending below the crankcase  44  and connected respectively to a front portion of the front cylinder  46  and a rear portion of the rear cylinder  48 , and an exhaust muffler  64  connected to the exhaust tubes  62  and disposed on the right-hand side of the rear wheel  28 . The exhaust assembly  60  serves to discharge exhaust gases from the engine  22  through the exhaust tubes  62  and the exhaust muffler  64 . 
         [0044]    The swing arm  26  extends substantially horizontally rearward from the pivot  24 , and the rear wheel  28  is rotatably supported on the rear end of the swing arm  26 . A brake device  28   a  in the form of a disk brake is mounted on one side of the rear wheel  28 . A rear cushion  66 , which resiliently connects the main frames  30  and the swing arm  26  to each other, is disposed upwardly of a front portion of the swing arm  26 . The rear cushion  66  serves to absorb vibrations generated when the motorcycle  12  travels. 
         [0045]    A seat  68  for passengers (a rider and a pillion passenger) to be seated thereon is disposed on the seat frames  32 . The seat  68  is of a tandem structure including a front seat  68   a  for the rider to sit on, and a rear seat  68   b  for the pillion passenger to sit on behind the front seat  68   a . A rear fender  70  is attached to rear portions of the seat frames  32 . The rear fender  70  extends horizontally rearward from the seat frames  32  and includes a rear portion extending obliquely downward. The rear fender  70  supports thereon a tail lamp unit  72  as an illuminating unit on a rear portion of the vehicle body. The tail lamp unit  72  includes a brake lamp  72   a  and a pair of left and right rear winker lamps  73 . The tail lamp unit  72  energizes and de-energizes the brake lamp  72   a  and the rear winker lamps  73  based on actions made by the rider. 
         [0046]    The motorcycle  12  includes a vehicle body cover  74  providing a design surface (appearance) of the vehicle body along the longitudinal direction thereof. The vehicle body cover  74  is made of a polymeric material such as acrylonitrile butadiene styrene (ABS), fiber-reinforced plastics (FRP), polypropylene (PP), or the like. 
         [0047]    The vehicle body cover  74  includes a headlight cover  76  covering the peripheral surface of the headlight  36 , a screen support cover  80  supporting a screen  78  above the headlight  36 , handle covers  82  covering front portions of the handle assembly  38 , a pair of left and right side cowls  84  extending rearwardly from respective opposite sides of the headlight  36 , and a rear cowl  86  extending obliquely rearward and upwardly along the seat frames  32  to cover opposite side surfaces of the seat frames  32 . 
         [0048]    The vehicle body cover  74  also includes a cowl support stay  88  supporting the headlight  36  and the screen support cover  80 . The cowl support stay  88  is fixed to front portions of the main frames  30 . The cowl support stay  88  supports thereon a meter unit  90 , which is disposed behind the headlight  36 , and also supports a pair of left and right front winker lamps  10  on respective opposite side surfaces thereof. 
         [0049]      FIG. 2  is an enlarged fragmentary front elevational view of a front upper portion of the motorcycle  12  shown in  FIG. 1 . As shown in  FIG. 2 , the headlight cover  76  and the screen  78  (screen support cover  80 ) provide a design surface of a front upper portion of the vehicle body. The design surface is of a streamlined shape gradually inclined rearwardly from a front central portion in the transverse direction and in the upward direction. 
         [0050]    The headlight cover  76  has opposite side surfaces covered with the side cowls  84 , providing a substantially triangular design surface, which has vertices defined at upper left and right ends and at a lower central end as viewed in front elevation. The headlight cover  76  has an opening  76   a  defined therein, which is shaped to allow a lens surface  36   a  of the headlight  36  to be seen as a substantially heart shape. The headlight cover  76  also has recesses  76   b  defined respectively in left and right surfaces thereof. The recesses  76   b  and confronting edges of the side cowls  84 , which extend therealong, jointly define apertures that open into the vehicle body cover  74 . The apertures serve to guide ram air toward the air cleaner  58  when the motorcycle  12  is driven. 
         [0051]    The headlight  36  is housed in the headlight cover  76  with the lens surface  36   a  exposed in a forward direction. The headlight  36  includes a low-beam bulb  92  disposed in a central upper position thereof, and a high-beam bulb  94  disposed in a central lower position thereof. The headlight  36  also includes a pair of left and right positioning light bulbs  96  disposed in respective transverse outer positions. 
         [0052]    The front winker lamps  10  have respective proximal ends  10   a  mounted on the cowl support stay  88  (see  FIG. 1 ) by attachments  98 , and which extend substantially horizontally outward along the transverse direction of the vehicle body. The front winker lamps  10  have respective transverse outer ends  10   b  that project outwardly, but terminate short of line segments Ls, which extend between the lower end of the opening  76   a  of the headlight cover  76  and the transverse outer ends of the handle covers  82 . When the upper portion of the vehicle body is viewed in front elevation, the handle covers  82 , the front winker lamps  10 , and the headlight cover  76  jointly define a design surface, which spreads transversely outward for better appearance in a well balanced fashion along an upward direction from the central area of a front portion of the headlight cover  76 . 
         [0053]    Furthermore, when the upper portion of the vehicle body is viewed in front elevation, the winker lamps  10  are spaced obliquely laterally from the positioning light bulbs  96  of the headlight  36 . The winker lamps  10  blink to produce direction indicating signals while the motorcycle  12  is being driven. In addition, at the same time that the positioning light bulbs  96  are energized, the winker lamps  10  are energized to emit a smaller amount of light than when the winker lamps  10  blink to produce the direction indicating signals. Accordingly, the winker lamps  10  also serve as positioning lights, i.e., auxiliary lights. More specifically, a total of four lights, i.e., the two left and right positioning light bulbs  96  and the two left and right winker lamps  10 , are simultaneously energized to make the motorcycle  12  highly visible to oncoming vehicles. 
         [0054]    As shown in  FIGS. 1 and 2 , the vehicle body cover  74  includes cowl guard pipes  100  extending from respective left and right main frames  30  forwardly along the side cowls  84 , and which are connected to a lower portion of the headlight cover  76 . The cowl guard pipes  100  provide a design surface on the front portion of the vehicle body, and also serve to prevent the vehicle body cover  74  from being damaged when the motorcycle  12  overturns. 
         [0055]      FIG. 3  is a view of a portion of the motorcycle  12  shown in  FIG. 1 , as viewed in the direction indicated by the arrow A in  FIG. 1 . As shown in  FIG. 3 , a handle switch case  41  of a switch unit  208  (see  FIG. 12 ) is mounted on the left handlebar  39  of the motorcycle  12 . The handle switch case  41  supports on a surface thereof a hazard switch HS for controlling hazard blinking (hazard mode), a headlight beam switch HLS for switching between high beam and low beam modes emitted from the headlight  36 , and a winker switch WS for controlling winker blinking (winker mode), arranged successively in this order along the rearward direction. Since the hazard switch HS, the headlight beam switch HLS, and the winker switch WS are positioned proximate to the handle assembly  38 , the rider can easily turn on and off such switches while manipulating the handle assembly  38 . 
         [0056]    According to the present embodiment, the meter unit  90  of the motorcycle  12  displays digital representations of the speed of the motorcycle  12  and the rotational speed of the engine  22  while the motorcycle  12  is being driven. The meter unit  90  is supported on the cowl support stay  88  behind the headlight  36  (see  FIG. 1 ). 
         [0057]    The meter unit  90  includes a speedometer liquid crystal screen  102  for displaying the speed of the motorcycle  12 , and a tachometer liquid crystal screen  104  for displaying the rotational speed of the engine  22 . The speedometer liquid crystal screen  102  and the tachometer liquid crystal screen  104  are disposed on a surface of the meter unit  90 , which is positioned forwardly of the handle assembly  38  and faces toward the rider sitting on the seat  68 . The meter unit  90  also includes a plurality of indicators or display lamps disposed in an upper area of the surface thereof for indicating various states of a driving system and an electrical system of the motorcycle  12 . More specifically, such indicators include a left winker indicator  106 , a high beam indicator  108 , a neutral indicator  110 , an ON-indicator  112  and an OFF-indicator  114  of a TCS (Traction Control System), and a right winker indicator  116 , arranged successively in this order from left to right as viewed by the rider. The left winker indicator  106  and the right winker indicator  116  are turned on when the front winker lamps  10  and the rear winker lamps  73  blink to indicate directions in which the motorcycle  12  is turned. The high beam indicator  108  is turned on when the high-beam bulb  94  of the headlight  36  is turned on to emit high-beam light. 
         [0058]    The neutral indicator  110  is turned on when the clutch of the motorcycle  12  is in a neutral position. The ON-indicator  112  and the OFF-indicator  114  are turned on based on states of the TCS. 
         [0059]    TCS refers to a system for calculating a slip ratio based on vehicle speed signals from the front wheel  20  and the rear wheel  28  while the motorcycle  12  is driven, and for controlling operation of the motorcycle  12  based on the calculated slip ratio. For example, if the TCS decides that the rear wheel  28  is slipping based on the calculated slip ratio, then the TCS adjusts the throttle (TH) opening with the TBW system of the throttle body  56 , in order to control the rate of the air-fuel mixture that is introduced into the front and rear cylinders  46 ,  48  so as to achieve a preset target slip ratio. The rotational speed of the engine  22 , and hence the rotational speed of the rear wheel  28 , are controlled to prevent the rear wheel  28  from slipping. 
         [0060]    The TCS can be manually switched between an ON (controlling) state and an OFF (non-controlling) state by the rider, using a selector button  118  disposed in a recess  84   a  defined in an upper surface of the left side cowl  84 . The selector button  118  is disposed at a position, which is spaced forwardly by a certain distance D1 (see  FIG. 1 ) from the handle switch case  41  mounted on the handle assembly  38 . Since the selector button  118  is spaced from the handle assembly  38 , the selector button  118  is not inadvertently touched by the rider while driving the motorcycle  12 . However, the selector button  118  can be reached by the rider only when the rider intends to operate the selector button  118 . The rider can switch the TCS from the ON state to the OFF state by pressing the selector button  118  continuously for a long time, and can switch the TCS from the OFF state back to the ON state by pressing the selector button  118  again continuously for a long time. The TCS may remain in the OFF state continuously until the ignition switch, i.e., the engine  22 , of the motorcycle  12  has been turned off. The TCS may automatically be returned to the ON state when the ignition switch is turned on again. 
         [0061]      FIG. 4  is a table showing turned-on and turned-off states of the ON-indicator  112  and the OFF-indicator  114  of the TCS shown in  FIG. 3 . The ON-indicator  112  and the OFF-indicator  114  display states of the TCS based on combinations of two states thereof, i.e., turned-on and turned-off states. When the ignition switch is initially turned on, both the ON-indicator  112  and the OFF-indicator  114  are turned on for about two seconds, in order to inform the rider that the electrical system of the motorcycle  12  is energized. 
         [0062]    Thereafter, the motorcycle  12  checks if the TCS is operating normally according to a self-diagnosis process (initial diagnosis process) before the motorcycle  12  is driven. At this time, the OFF-indicator  114  is turned off, and only the ON-indicator  112  is turned on. When the initial diagnosis process is finished, the ON-indicator  112  is turned off automatically. 
         [0063]    When the motorcycle  12  is driven with the TCS in the ON (controlling) state, as long as the motorcycle  12  is driven normally, i.e., as long as the TCS determines that the rear wheel  28  is not slipping, both the ON-indicator  112  and the OFF-indicator  114  are turned off. 
         [0064]    If the TCS decides that the rear wheel  28  is slipping, then the TCS controls the TBW system of the throttle body  56  as described above. While the TCS controls the TBW system, the ON-indicator  112  is controlled to blink, in order to inform the rider that the TCS is in operation. 
         [0065]    If the rider presses the selector button  118  continuously for a long time in order to bring the TCS into an OFF (non-controlling) state when the motorcycle  12  is driven, then the OFF-indicator  114  is continuously turned on, in order to inform the rider that the TCS is not in operation. 
         [0066]    If the TCS detects a failure (erroneous operation) according to a self-diagnosis process, then the ON-indicator  112  is turned on in order to inform the rider that the TCS is not working normally. 
         [0067]    As described above, the motorcycle  12  lets the rider know the states of the TCS based on combinations of turned-on and turned-off states of the ON-indicator  112  and the OFF-indicator  114 . 
         [0068]    Structural details of the front winker lamps  10  will be described below with reference to  FIGS. 5 through 11 . Since the left and right front winker lamps  10  are symmetrical in structure, only the right winker lamp  10  as viewed from the position of the rider will be described in detail below, and detailed description of the left winker lamp  10  is omitted. 
         [0069]      FIG. 5  is an enlarged front elevational view of the winker lamp  1 C shown in  FIG. 2 .  FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 5 , and  FIG. 7  is a cross-sectional view taken along line VII-VII of  FIG. 5 .  FIG. 8  is a front elevational view showing a state in which an outer lens of the winker lamp  10  of  FIG. 5  is detached therefrom,  FIG. 9  is a perspective view showing the winker lamp  10  of  FIG. 8 ,  FIG. 10  is a front elevational view showing a state in which an inner lens of the winker lamp  10  of  FIG. 8  is detached therefrom, and  FIG. 11  is a rear view of the winker lamp  10  of  FIG. 5 . 
         [0070]    As shown in  FIG. 6 , the winker lamp  10  according to the present embodiment includes a base  120 , an outer lens  122  mounted on a front side of the base  120 , a board  126  with a plurality of light-emitting diodes (LEDs)  124  mounted thereon and housed in an inner space  125  defined between the base  120  and the outer lens  122 , and an inner lens  128  disposed between the outer lens  122  and the board  126 . The winker lamp  1 C also includes a harness  130 , which is connected to a mounting surface  126   a  of the board  126  with the LEDs  124  mounted thereon. The harness  130  includes wires electrically connected to the LEDs  124 . 
         [0071]    As shown in  FIG. 5 , the base  120  has a proximal end, which is mounted on the attachment  98 . The base  120  has an outer profile, which grows gradually wider vertically in a direction away from the proximal end toward a widest portion  120   a  near the proximal end, and then becomes gradually narrower from the widest portion  120   a  toward a vertically central point. As shown in  FIGS. 6 and 7 , the base  120  has a substantially concave or cup-like cross-sectional shape with the board  126  housed therein. 
         [0072]    As shown in  FIG. 6 , the base  120  has a plurality (three in  FIG. 6 ) of protrusive rests  132  projecting forwardly from a rear wall  120   b , which serves as the bottom of the concave cross-sectional shape. The protrusive rests  132  support the board  126  thereon in spaced relationship to the rear wall  120   b . Therefore, heat generated by the LEDs  124  when the LEDs  124  are energized to emit light is dissipated or radiated into the air surrounding the board  126 . 
         [0073]    The base  120  is molded from a synthetic resin, which is capable of withstanding the heat generated by the LEDs  124  when the LEDs  124  emit light. For example, a BMC (Bulk Molding Compound) resin may be used as the synthetic resin. 
         [0074]    As shown in  FIGS. 8 and 9 , the base  120  has a front mounting surface  134  on which the outer lens  122  and the inner lens  128  are mounted. The front mounting surface  134  includes a flat area (flat surface)  134   a  that extends from the widest portion  120   a  along a transverse outward direction of the motorcycle  12 , and a slanted area  134   b , which is slanted obliquely from the widest portion  120   a  along an opposite transverse inward direction of the motorcycle  12 . 
         [0075]    As shown in  FIGS. 5 and 6 , the proximal end of the base  120  is fastened to the attachment  98  by a mounting screw  138 . The attachment  98  has a harness channel  136  defined therein, which extends in a crank shape from the proximal end thereof in the transverse outward direction of the motorcycle  12 . The harness  130  is guided from the proximal end of the attachment  98  through the harness channel  136  to the base  120 . 
         [0076]    The mounting screw  138  is placed in the harness channel  136  and is threaded into the base  120  through a washer  138   a  and the attachment  98  in the transverse outward direction of the motorcycle  12 , thereby fastening the base  120  to the attachment  98 . The attachment  98  preferably is made from an elastic synthetic resin, such as synthetic rubber or the like. Since the attachment  98  is elastic, the attachment  98  can absorb vibrations caused when the motorcycle  12  is driven, and hence the attachment  98  is capable of supporting the winker lamp  10  stably. 
         [0077]    A mounting bolt  142  includes a head, which is embedded in the proximal end of the attachment  98 , and a tip end that extends in the transverse inward direction of the motorcycle  12 . The mounting bolt  142 , with the flange  144  mounted thereon, is embedded in the attachment  98  when the attachment  98  is molded. Therefore, the mounting bolt  142  is securely held in the attachment  98  and is prevented from being removed therefrom. The mounting bolt  142  extends through a support  140 , which is mounted on the cowl support stay  88 . 
         [0078]    The support  140  is molded from a synthetic resin and is fitted into the cowl support stay  88 . The mounting bolt  142  is inserted into a bolt insertion hole  140   a  defined in the support  140 , and is secured to the support  140  by a nut  142   a , which is threaded over the tip end of the mounting bolt  142 . Thus, the winker lamp  10  is supported firmly on the cowl support stay  88  by the attachment  98  and the support  140 . 
         [0079]    The base  120  has two holes, i.e., a first hole  146  and a second hole  148 , defined in an end wall to which the attachment  98  is mounted. The first hole  146  and the second hole  148  communicate with the inner space  125  defined between the base  120  and the outer lens  122 , or more specifically, with a partial space  172 , to be described later. The first hole  146  is larger in diameter than the second hole  148 . A grommet (retaining member)  150 , which serves as a harness holder, is inserted into the first hole  146 , and holds the harness  130  therein. 
         [0080]    The grommet  150  has an insertion hole  152  defined therein through which the harness  130  extends. The insertion hole  152  is defined by an inner circumferential surface of the grommet  150 , which has a plurality of teeth  152   a  held in close contact with the outer circumferential surface of the harness  130 . The grommet  150  has a flange  150   a  on one end thereof, which is disposed in the inner space  125 . The flange  150   a  has a diameter, which is greater than the first hole  146  in the base  120 . The grommet  150  also has a ridge  150   b  on the outer circumferential surface of an intermediate portion thereof, which extends in a transverse inward direction of the motorcycle  12 . The flange  150   a  and the ridge  150   b  engage with respective opposite open ends of the first hole  146 , thereby securely retaining the grommet  150  on the base  120 . The grommet  150  holds the harness  130 , which is inserted therein, and prevents water from entering into the winker lamp  10  from between the harness  130  and the surface that defines the insertion hole  152 , and from between the surface that defines the first hole  146  and the grommet  150 . 
         [0081]    The second hole  148  that is defined in the attachment  98  has an open end which is open into the inner space  125  at a position facing the board  126  and the LEDs  124 . The second hole  148  serves to vent the inner space  125 , equalizing the air pressure in the inner space  125  to the air pressure outside the winker lamp  10  when the air pressure in the inner space  125  is increased by the heat generated when the LEDs  124  emit light. The second hole  148  has an opposite open end that is open at the outer end of the base  120  and which is covered with an air-permeable sheet  154  that absorbs water. The air-permeable sheet  154  prevents water from entering into the inner space  125  through the second hole  148 . 
         [0082]    The outer lens  122  of the winker lamp  10  is made of a highly transparent synthetic resin. The outer lens  122  that is mounted on the front side of the base  120  serves as a front lens surface of the winker lamp  10 . As shown in  FIG. 5 , the outer lens  122  has an outer profile, which is substantially in agreement with the peripheral edge of the base  120  as viewed in plan. The outer lens  122  is of a convex cross-sectional shape (see  FIGS. 6 and 7 ) and has a rear open end  122   a  extending along the shape of the front mounting surface  134  of the base  120 , which includes the flat area  134   a  and the slanted area  134   b . More specifically, the rear open end  122   a  of the outer lens  122  snugly engages the front mounting surface  134  of the base  120  with no gaps therebetween, so that the outer lens  122  can be welded to the base  120 . 
         [0083]    The outer lens  122  is mounted on and joined to the base  120  by a vibration welding process. In the vibration welding process, the outer lens  122  is vibrated parallel to the base  120 . Since the outer lens  122  is vibration-welded to the base  120 , a hermetic seal is created to prevent rainwater, dust, dirt, etc., from entering into the inner space  125 . 
         [0084]    The outer lens  122  has an inner surface, which faces toward the inner space  125 . The inner surface is cut into an outer lens cut region  122   b  along a plurality of cut lines that extend horizontally, i.e., along the transverse direction of the motorcycle  12 , for thereby vertically diffusing light that is emitted from the LEDs  124 . The outer lens  122  has an outer surface, which is not cut, but which is finished to a smooth surface to prevent mud, dirt, etc., from adhering thereto. 
         [0085]    As shown in  FIG. 10 , the board  126 , which is mounted on the base  120 , is in the form of an elongate plate extending along the transverse direction of the motorcycle  12 , with two LEDs  124  mounted on the mounting surface  126   a  thereof. The LEDs  124  are electrically connected by a reflow soldering process to an electrically conductive pattern that is printed on the mounting surface  126   a.    
         [0086]    According to the present embodiment, the board  126  is of a laminated structure having an alternate assembly of layers, which include board members made of, e.g., glass epoxy or phenolic paper, and copper foil, not shown. The board  126  has tubular through holes (not shown) defined therein at positions near the LEDs, and through which the electrically conductive pattern on the mounting surface  126   a  is electrically connected to an electrically conductive pattern on the reverse side of the board  126 . The laminated structure and the through holes of the board  126  are effective to conduct heat generated on the mounting surface  126   a  at a time when the LEDs  124  emit light to the lower layers of the board  126  and into the space below the board  126 . Since the generated heat is dissipated from the board  126 , such heat is prevented from being concentrated on and around the LEDs  124 . Therefore, the winker lamp  10  exhibits an increased heat radiating capability. 
         [0087]    The board  126  has a screw insertion hole  156  defined centrally therein, and protrusive rest insertion holes (board welding parts)  158  defined therein at transverse outer ends thereof, and joints between the LEDs  124  and the harness  130 . A fixing screw  160  is inserted through the screw insertion hole  156  and is threaded into an internally threaded screw hole  132   a  defined in the central protrusive rest  132 , which projects from the rear wall  120   b  of the base  120 . The left and right protrusive rests  132  also project from the rear wall  120   b  of the base  120  and have respective ends inserted into the protrusive rest insertion holes  158 , and which are crimped by high-frequency induction heating into welded engagement with the peripheral edges of the protrusive rest insertion holes  158 . Since the left and right protrusive rests  132  are securely joined to the board  126  around the protrusive rest insertion holes  158 , the number of screws used for fastening the board  126  to the base  120  is reduced, and hence the total number of parts is reduced. 
         [0088]    The harness  130 , which is electrically connected to the LEDs  124  by the electrically conductive pattern, is connected to the mounting surface  126   a  of the board  126 . The harness  130  has a proximal end thereof electrically connected to the electrical system of the motorcycle  12 , and functions to supply electric power to the LEDs  124 . A sheath of the harness  130  is preferably, but not necessarily, made of an insulative and flexible synthetic resin, which is resistant to heat generated when the LEDs  124  emit light. 
         [0089]    The two LEDs  124  that are mounted on the board  126  comprise LEDs for emitting an amount of light at a color temperature suitable for use as the light source of the winker lamps  10 . In particular, since the winker lamps  10  are aimed in a direction in which the motorcycle  12  is to be turned, the winker lamps  10  should preferably comprise devices for emitting high-intensity light with a wide directivity angle, so that light emitted from the winker lamps  10  can be diffused within a wide illumination range. 
         [0090]    As shown in  FIG. 6 , the inner lens  128 , which is disposed in the inner space  125 , includes a lens cut region  162  on the front surface of a base portion  161 , which extends along the transverse direction of the motorcycle  12 , a pair of protruding portions  164  disposed at positions facing the respective LEDs  124  and which project toward the respective LEDs  124 , and a roof  166  extending from the base portion  161  near one of the protruding portions  164 , along the transverse inward direction of the motorcycle  12 . 
         [0091]    As shown in  FIGS. 7 through 9 , the base portion  161  of the inner lens  128  includes a welding arm  168  on a distal end thereof, i.e., on a transverse outer end thereof, and welding arms  168  on respective upper and lower portions of a proximal end thereof, i.e., on a transverse inner end thereof. The welding arms  168  are joined to the front mounting surface  134  of the base  120  by a vibration welding process. Therefore, the inner lens  128  is supported on the base  120  and is disposed at a given position in the inner space  125 . 
         [0092]    The lens cut region  162  has a plurality of vertical cut lines spaced along the transverse direction of the motorcycle  12 . As shown in  FIGS. 6 and 9 , the lens cut region  162  has a plurality of arcuate convex lens surfaces disposed between the cut lines. The arcuate convex lens surfaces serve to laterally diffuse light emitted from the LEDs  124  and that is transmitted through the inner lens  128 . Therefore, the lens cut region  162  functions to disperse light that travels straight from the board  126  toward the outer lens  122 , as viewed in front elevation. 
         [0093]    The two protruding portions  164  are disposed side by side on the rear surface of the inner lens  128 , in respective alignment with the two LEDs  124  mounted on the board  126 . As shown in  FIG. 6 , the protruding portions  164  are substantially part-spindle-shaped, in that the protruding portions  164  are tapered arcuately from the base portion  161 , i.e., the lens cut region  162 , toward the LEDs  124 . The protruding portions  164  have respective crests with cavities  170  defined therein, which are concave toward the base portion  161 . The cavities  170  keep the protruding portions  164  spaced from the LEDs  124  by a certain distance, for preventing heat generated upon emission of light from the LEDs  124  from being transmitted to the inner lens  128 . 
         [0094]    The roof  166  extends from the base portion  161  near one of the protruding portions  164  along the transverse inward direction of the motorcycle  12 , i.e., to the right in  FIG. 6 . The roof  166  is in the shape of a flat plate, which is thinner than the protruding portions  164 , with the lens cut region  162  extending over a front surface of the roof  166 . The roof  166  has a flat rear surface joined to the base portion  161  near the protruding portion  164 , and extending parallel to the board  126 , which is disposed behind the roof  166  in facing relation thereto. 
         [0095]    Since the inner lens  128  is welded to the base  120  and is supported in a given position in the inner space  125 , each of the winker lamps  10  has a relatively wide partial space  172  defined between the rear surface of the roof  166  and the front surface of the board  126 . The partial space  172  is surrounded by the protruding portion  164 , the roof  166 , the board  126 , and a transverse inner side wall of the base  120 . The harness  130  is placed inside the partial space  172 . More specifically, the harness  130  extends from the insertion hole  152  in the grommet  150 , which is supported on the transverse inner side wall of the base  120 , into the partial space  172  where the harness  130  is connected to the mounting surface  126   a  of the board  126 . 
         [0096]    The lens cut region  162  on the front surface of the roof  166  conceals from view the harness  130 , which extends into the partial space  172  as viewed in plan. More specifically, although ambient light that enters the winker lamp  10  is reflected by the harness  130 , the reflected light is diffused by the lens cut region  162 , and therefore the harness  130  is made less visible and is concealed from view. 
         [0097]    The roof  166  extends to such an extent that the transverse inner end thereof is substantially aligned with the flanged end of the grommet  150 . Inasmuch as the roof  166  extends to the end of the grommet  150 , which projects into the partial space  172 , the roof  166  covers the harness  130 , which extends from the end of the grommet  150  into the partial space  172 , thereby making the harness  130  much less visible. 
         [0098]    Assembly of the winker lamp  10  according to the present embodiment is performed by welding in succession each of the members (i.e., the board  126 , the inner lens  128 , the outer lens  122 ) onto the base  120 . As shown in  FIG. 11 , on the rear surface (back surface) of the base  120 , a pair of grooves (support members)  174  are formed. The pair of grooves  174  are engraved vertically on the base  120  in the transverse direction of the vehicle and are formed in flat shapes on the bottom thereof (see  FIG. 7 ). Upon assembly of the winker lamp  10 , a fixing jig (not shown) for fixing the base  120  is placed in abutment against the pair of grooves  174 . More specifically, by supporting through abutment the jig and bottoms of the grooves  174 , which extend in the axial direction, welding can be carried out while the base  120  is stably supported by the jig. Owing thereto, since shaking of the base  120  is reduced during vibration welding or high frequency crimping of each of the members, working efficiency is improved when the winker lamp  10  is assembled. 
         [0099]    In the case that the board  126  is assembled onto the base  120 , the protrusive rest insertion holes  158  are fitted onto the protrusive rests  132  of the base  120 , and further, the fixing screw  160  is threaded into the screw hole  132   a  via the screw insertion hole  156 , whereby the board  126  is fixed (screwed) onto the base  120 . Thereafter, by performing high frequency crimping of the protrusive rests  132 , which are inserted through the protrusive rest insertion holes  158 , the board  126  and the base  120  are fixed firmly to each other. In this manner, by partially welding the board  126  and the base  120 , the screws required to screw-fasten the board  126  are few in number, and therefore, the number of component parts can be reduced. Further, because it is unnecessary to provide a plurality of screw holes  132   a  in the base  120 , the base  120  itself can be reduced in size. 
         [0100]    As shown in  FIG. 10 , two LEDs  124  are mounted on the board  126  such that intervals exist between terminals  124   a  of the LEDs  124  and the two protrusive rest insertion holes  158 , which are separated by a predetermined distance D2. In this manner, welding debris of the protrusive rests  132  can be prevented from adhering to the terminals  124   a  as a result of high frequency crimping. 
         [0101]    After the board  126  has been assembled on the base  120 , the inner lens  128  is welded to the flat area  134   a  of the base  120 . In this case, the welding arms  168 , which are provided on the base portion  161  of the inner lens  128 , and the front mounting surface  134  of the base  120  are fixed to each other by vibration welding. As shown in  FIG. 8 , on the front mounting surface  134 , plural wall members  176  are erected on upper and lower sides of the welded portions where the welding arms  168  are welded onto the front mounting surface  134  of the base  120 . The wall members  176  function to prevent welding debris, which occurs due to vibration welding of the inner lens  128 , from being ejected onto the front mounting surface  134 , and toward sides of the welded portions of the outer lens  122 . Consequently, adhesion of welding debris on the front mounting surface  134 , possibly leading to difficultly in welding of the outer lens  122 , and impairment of the appearance of the winker lamp  10  can be suppressed. 
         [0102]    In a state where the inner lens  128  is welded to the base  120 , as shown in  FIG. 6 , with respect to an imaginary line Li that extends in the transverse direction of the vehicle through the welded portions of the base  120  and the inner lens  128 , the base portion  161 , the lens cut region  162 , and the roof  166  are arranged nearer the outer lens  122  in relation to the imaginary line Li, whereas apex sides of the protruding portions  164  are arranged nearer the board  126  in relation to the imaginary line Li. More specifically, in the winker lamp  10 , as viewed in the plane, the inner lens  128  (and protruding portions  164  thereof) are arranged so as to occupy large part of the inner space  125 , whereby the LEDs  124  and the harness  130  can be prevented, by the inner lens  128 , from being seen from vertical (lateral) directions, as well as from left and right (transverse) directions of the vehicle. 
         [0103]    After the inner lens  128  has been assembled on the base  120 , the outer lens  122  is welded at an outside position in relation to the mounting position of the inner lens  128  on the front mounting surface  134  of the base  120 . During welding, as shown in  FIG. 5 , the outer lens  122  covers the front mounting surface  134  of the base  120 , and the boundary (portion to be welded) between the rear side open end of the outer lens  122  and the peripheral edge of the front mounting surface  134  is fixed by vibration welding. In this case, because the outer lens  122  and the inner lens  128  are welded onto the same flat area  134   a , the outer lens  122  and the inner lens  128  can easily be welded without large variations in the height position of the welding surface. Further, during welding of the outer lens  122  as well, welding debris can be prevented by the wall members  176 , which are disposed on the mounting surface  134 , from being directed toward welded portions of the inner lens  128 . 
         [0104]    In this manner, in the winker lamp  10 , by welding the board  126 , the inner lens  128 , and the outer lens  122 , such members can be mutually fixed and assembled together as a single unit. 
         [0105]    Next, details of a control system (lighting control system  11 ) for controlling blinking of the winker lamp  10  will be described below.  FIG. 12  is a schematic block diagram of a circuit arrangement of the lighting control system  11  for the winker lamp  10 . 
         [0106]    The vehicular lighting control system  11  has a total of four winker lamps, i.e., the left and right front winker lamps  10 , and the left and right rear winker lamps  73 . In order to distinguish the four winker lamps from each other in the circuit arrangement, in  FIG. 12 , the left front winker lamp is denoted by LF, the left rear winker lamp is denoted by LR, the right front winker lamp is denoted by RF, and the right rear winker lamp is denoted by RR. 
         [0107]    The vehicular lighting control system  11  includes the winker switch WS and the hazard switch HS for blinking the winker lamps LF, LR, RF, RR, and also has a control circuit (controller)  200  for controlling blinking of the winker lamps LF, LR, RF, RR. The control circuit  200  controls the winker mode (left winker mode or right winker mode) to blink either the left winker lamps LF, LR or the right winker lamps RF, RR based on a signal from the winker switch WS, which is turned on by the rider, and also controls the hazard mode to blink both the left winker lamps LF, LR and the right winker lamps RF, RR simultaneously based on a signal from the hazard switch HS, which is turned on by the rider. 
         [0108]    The ignition switch of the motorcycles  12  is denoted by IS. The ignition switch IS, the winker switch WS, and the hazard switch HS are connected to respective input ports of the control circuit  200 . The ignition switch IS, the winker switch WS, and the hazard switch HS have respective high-side terminals connected to the positive terminal of a battery (power supply)  202 . In other words, the ignition switch IS, the winker switch WS, and the hazard switch HS are connected between the control circuit  200  and the battery  202 . Therefore, the control circuit  200  accurately judges whether or not the ignition switch IS and the winker switch WS are turned on by detecting an input voltage (signal) that is applied from the battery  202  when the winker switch WS and the hazard switch HS are turned on. 
         [0109]    The control circuit  200  has output ports connected to LED arrays LF-LED, LR-LED, RF-LED, RR-LED, which serve as light sources of the winker lamps LF, LR, RF, RR, an LED  204  as a light source of the left winker indicator  106 , and an LED  206  as a light source of the right winker indicator  116 . The LED arrays LF-LED, LR-LED, RF-LED, RR-LED, the LED  204 , and the LED  206  have cathode terminals thereof connected to ground, together with the negative terminal of the battery  202 . 
         [0110]    The ignition switch IS is a switch for starting and stopping the engine  22 , which is connected by wires between the control circuit  200  and the battery  202 . The ignition switch IS may comprise a key switch. When the ignition switch IS is turned on, e.g., when the key inserted therein is turned, the battery  202  is connected to the control circuit  200  for supplying electric power to the control circuit  200 . More specifically, when the ignition switch IS is turned on, the battery  202  applies a voltage of 5 V, for example, to the control circuit  200 . 
         [0111]    The winker switch WS and the hazard switch HS each comprises a selector switch, which completes or breaks an electric circuit when the winker switch WS or the hazard switch HS is mechanically turned on or off by the rider. The winker switch WS and the hazard switch HS are supported on the handle switch case  41  of the switch unit  208  on the left handlebar  39  (see  FIG. 3 ). The winker switch WS and the hazard switch HS are connected in parallel within the switch unit  208 . 
         [0112]    More specifically, the winker switch WS has two output contacts  210  (left switch contact  210   a  and right switch contact  210   b ), which are connected to the control circuit  200 , and an input contact  212 , which is connected to the battery  202 . The output contacts  210  and the input contact  212  are included within the switch unit  208 . The left switch contact  210   a  serves as a connection terminal for instructing the left winker lamps LF, LR to blink, whereas the right switch contact  210   b  serves as a connection terminal for instructing the right winker lamps RF, RR to blink. When the rider tilts a trigger lever connected to the input contact  212  in one or the other direction, the input contact  212  becomes connected to the left switch contact  210   a  or the right switch contact  210   b , whereupon the left switch contact  210   a  or the right switch contact  210   b , which is connected to the input contact  212 , applies the input voltage from the battery  202  to the control circuit  200 . 
         [0113]    The hazard switch HS has two output contacts  214  (left switch contact  214   a  and right switch contact  214   b ) connected to the control circuit  200 , and an input contact  216  connected to the battery  202 . The output contacts  214  and the input contact  216  are included within the switch unit  208 . The output contacts  214  and the input contact  216  are connected in parallel with the output contacts  210  and the input contact  212  of the winker switch WS. The hazard switch HS may comprise a three-contact switch, which mechanically connects three contacts simultaneously when a mechanical button (not shown), such as a pushbutton, is pressed by the rider. The hazard switch HS, which is constructed in the foregoing manner, is simple in structure and inexpensive to manufacture. When the rider turns on the hazard switch HS, the three contacts are connected together simultaneously, i.e., the input contact  216  is connected to both the left switch contact  214   a  and the right switch contact  214   b , which simultaneously apply the input voltage from the battery  202  to the control circuit  200 . 
         [0114]    The left switch contact  210   a  of the winker switch WS and the left switch contact  214   a  of the hazard switch HS are connected to a harness (wiring)  218 , which is connected to the control circuit  200 . The right switch contact  210   b  of the winker switch WS and the right switch contact  214   b  of the hazard switch HS are connected to another harness  218 , which is connected to the control circuit  200 . The input contact  212  of the winker switch WS and the input contact  216  of the hazard switch HS are connected to a harness (wiring)  220 , which is connected to the battery  202 . With the winker switch WS and the hazard switch HS being connected in parallel, the harnesses  218  are connected to the harness  220  when the winker switch WS and the hazard switch HS are turned on. In the vehicular lighting control system  11 , the battery  202  can thus be connected to the control circuit  200  by the harnesses  218 ,  220 , and the number of harnesses used is smaller than if the winker switch WS and the hazard switch HS were connected separately between the battery  202  and the control circuit  200 . 
         [0115]    The LEDs  124  of the winker lamp  10  are used as each of the LED arrays LF-LED, LR-LED, RF-LED, RR-LED, which serve as light sources of the winker lamps LF, LR, RF, RR that are connected to the output ports of the control circuit  200 . In the present embodiment, each of the light sources comprises two series-connected LEDs  124 . The LED arrays LF-LED, LR-LED, RF-LED, RR-LED are energized to emit light when supplied with electric current at given times from the control circuit  200 . The meter unit  90  includes an instrument panel  90   a  (see  FIG. 3 ), which supports thereon the LEDs  204 ,  206  of the left winker indicator  106  and the right winker indicator  116 . The LEDs  204 ,  206  may be LEDs that emit a smaller amount of light than the LEDs  124 . 
         [0116]    The control circuit  200  has a left switch input port  222 , a right switch input port  224 , two SW input circuits (input voltage determiners)  226 , a holding circuit (holder)  228 , a 5V regulator  230 , four constant-current circuits  232 , four current detecting circuits  234 , two indicator drivers  236 , and a CPU (judging means)  238 . 
         [0117]    The left switch input port  222  and the right switch input port  224  function as parts of the input ports of the control circuit  200 . The left switch input port  222  has a high-side terminal, which is connected to the left switch contacts  210   a ,  214   a  of the winker switch WS and the hazard switch HS, and a low-side terminal, which is connected to one of the SW input circuits  226 . Therefore, the left switch input port  222  introduces an input voltage into the control circuit  200 , which is delivered from the left switch contacts  210   a ,  214   a.    
         [0118]    The right switch input port  224  has a high-side terminal, which is connected to the right switch contacts  210   b ,  214   b  of the winker switch WS and the hazard switch HS, and a low-side terminal, which is connected to the other of the SW input circuits  226 . Therefore, the right switch input port  224  introduces an input voltage into the control circuit  200 , which is delivered from the right switch contacts  210   b ,  214   b.    
         [0119]    The SW input circuit  226  is connected between the left switch input port  222  or the right switch input port  224  and the CPU  238 , and comprises a circuit arrangement for determining the voltage value of an input voltage that is delivered from the left switch input port  222  or the right switch input port  224 . 
         [0120]    The control circuit  200  normally receives an input voltage that is applied when the winker switch WS or the hazard switch HS is turned on. In addition, when a leakage current is generated in the switch unit  208 , the control circuit  200  may also receive a voltage based on the leakage current. A leakage current is generated in the switch unit  208 , for example, if rain water or the like enters the winker switch WS or the hazard switch HS, which is exposed to the external environment, thereby electrically connecting the input contact  212  or  216  to the output contact  210  or  214 . The SW input circuit  226  functions to block a voltage that is based on such a leakage current, and to detect only an input voltage applied when the winker switch WS or the hazard switch HS is turned on, so as to output a predetermined signal (voltage value) to the CPU  238 . 
         [0121]    The holding circuit  228  has input terminals connected respectively to the CPU  238  and the battery  202 , and an output terminal connected to the 5V regulator  230 . The holding circuit  228  functions to maintain the CPU  238  and the battery  202  in connection with each other, based on the hazard mode of the winker lamps LF, LR, RF, RR as determined by the CPU  238 . More specifically, when the winker lamps LF, LR, RF, RR operate in the hazard mode, the CPU  238  inputs an ON signal to the holding circuit  228 , and the holding circuit  228  keeps the CPU  238  and the battery  202  connected to each other, as long as the ON signal is input to the holding circuit  228 . 
         [0122]    Consequently, even if the ignition switch IS is turned off, i.e., even if the engine  22  is stopped, when the winker lamps LF, LR, RF, RR are operating in the hazard mode, the holding circuit  228  enables the voltage from the battery  202  to be applied continuously to the CPU  238 , in order to keep the hazard mode operational until the hazard switch HS has been turned off by the rider. The CPU  238  thus operates to keep the winker lamps LF, LR, RF, RR operating in the hazard mode, thereby making the motorcycle  12  highly visible and noticeable even when the engine  22  is at rest. 
         [0123]    When the hazard switch HS is turned off by the rider in order to stop the winker lamps LF, LR, RF, RR from operating in the hazard mode, the holding circuit  228  disconnects the battery  202  and the CPU  238  from each other, thereby stopping supply of voltage from the battery  202  to the CPU  238 . Since supply of voltage from the battery  202  to the CPU  238  remains stopped unless the ignition switch IS is turned on again, the winker lamps LF, LR, RF, RR are prevented from becoming energized (i.e., from blinking), even if the winker switch WS or the hazard switch HS is turned on after the engine  22  has been stopped. Therefore, the winker lamps LF, LR, RF, RR will not operate in the hazard mode if a third party, for example, turns on the hazard switch HS. 
         [0124]    The 5V regulator  230  has an input terminal, which is connected to the ignition switch IS and to the output terminal of the holding circuit  228 , and an output terminal, which is connected to the CPU  238 . The 5V regulator  230  has a function to decrease the voltage from the battery  202  to a drive voltage of 5 V, for thereby energizing the CPU  238  and stably supplying the drive voltage of 5 V to the CPU  238 . The constant-current circuits  232  supply a prescribed amount of current to the winker lamps LF, LR, RF, RR, and are associated respectively with the winker lamps LF, LR, RF, RR. The constant-current circuits  232  have respective input terminals, which are connected to the CPU  238  and to the battery  202 , and respective output terminals, which are connected to the respective current detecting circuits  234  and to the respective LED arrays LF-LED, LR-LED, RF-LED, RR-LED of the winker lamps LF, LR, RF, RR. 
         [0125]    The constant-current circuits  232  receive winker blinking signals S L , S R , S H  sent from the CPU  238 , connect the battery  202  and the LED arrays LF-LED, LR-LED, RF-LED, RR-LED to each other, and supply prescribed currents from the battery  202  to the LED arrays LF-LED, LR-LED, RF-LED, RR-LED to enable the LED arrays LF-LED, LR-LED, RF-LED, RR-LED to emit light. 
         [0126]    Among the winker lamps LF, LR, RF, RR, the winker lamps LF, RF also serve as positioning lights, which emit a smaller amount of light than when the winker lamps blink to produce direction indicating signals while the motorcycle  12  is being driven. The constant-current circuits  232 , which are connected to the winker lamps LF, RF, include respective circuits for supplying a constant current for the positioning lights from the battery  202 . 
         [0127]    The current detecting circuits  234  have respective input terminals, which are connected to the constant-current circuits  232 , and respective output terminals, which are connected to the CPU  238 . The current detecting circuits  234 , which are connected in this manner, supply the CPU  238  with feedback information concerning operation of the constant-current circuits  232 . More specifically, in the event of a disconnection between the constant-current circuits  232  and the LED arrays LF-LED, LR-LED, RF-LED, RR-LED, no current flows from the constant-current circuits  232 , even if the constant-current circuits  232  receive the blinking signals S L , S R , S H  from the CPU  238 . At this time, the current detecting circuits  234 , which detect current values of the constant-current circuits  232 , confirm that a disconnection has occurred between the constant-current circuits  232  and the LED arrays LF-LED, LR-LED, RF-LED, RR-LED. Since the current detecting circuits  234  are connected respectively to the constant-current circuits  232 , the current detecting circuits  234  can confirm respective disconnections that may occur with respect to the constant-current circuits  232 . Consequently, the control circuit  200  can detect such disconnections with increased accuracy. 
         [0128]    The indicator drivers  236 , which supply a prescribed amount of current to the LEDs  204 ,  206  of the left winker indicator  106  and the right winker indicator  116 , are connected respectively to the LEDs  204 ,  206 . The indicator drivers  236  have respective input terminals, which are connected to the CPU  238 , and respective output terminals, which are connected to the LEDs  204 ,  206  of the left winker indicator  106  and the right winker indicator  116 . The indicator drivers  236  receive the winker blinking signals S L , S R , S H  from the CPU  238 , and supply a prescribed current from the battery  202  to the LEDs  204 ,  206  so as to enable the LEDs  204 ,  206  to emit light. 
         [0129]    The CPU  238  comprises a microprocessor (microcomputer) of known nature for performing processing sequences therein, the microprocessor having input and output interfaces. The CPU  238  may be combined with an ECU (Engine Control Unit), not shown, for controlling the engine  22 . 
         [0130]    The CPU  238  judges whether or not the winker switch WS and the hazard switch HS are turned on or off, and controls light emission from the LED arrays LF-LED, LR-LED, RF-LED, RR-LED of the winker lamps LF, LR, RF, RR, and the LEDs  204 ,  206  of the left winker indicator  106  and the right winker indicator  116 , based on such a judgment. The CPU  238  stores therein a judging program, not shown, for judging whether or not the winker switch WS and the hazard switch HS are turned on or off, and performs a judging process based on such a judging program. 
         [0131]    The CPU  238  has a register (not shown) of three or more bits for managing energization of the winker lamps LF, LR, RF, RR in each cycle of operation. The winker modes (left winker mode and right winker mode) and the hazard mode of the winker lamps LF, LR, RF, RR are controlled by the CPU  238  based on flags (left winker mode flag, right winker mode flag, and hazard mode flag), which are set in the register by the CPU  238 . 
         [0132]    For example, if the CPU  238  sets the left winker mode flag to 1 (true) in the register, then the CPU  238  outputs winker blinking signals S L  to the constant-current circuits  232  for blinking the left winker lamps LF, LR, and if the CPU  238  sets the right winker mode flag to 1 in the register, then the CPU  238  outputs winker blinking signals S R  to the constant-current circuits  232  for blinking the right winker lamps RF, RR. If the CPU  238  sets the hazard mode flag to 1 in the register, then the CPU  238  outputs winker blinking signals S H  to the constant-current circuits  232  for blinking the winker lamps LF, LR, RF, RR. 
         [0133]    The winker blinking signals S L , S R , S H  are pulse signals that have a repetitive pattern of alternate high and low levels at a prescribed cyclic period. The winker blinking signals S L , S R , S H  are sent to the constant-current circuits  232  depending on the left winker mode, the right winker mode, and the hazard mode, which are determined by the judging process. When the winker blinking signals S L , S R , S H  are of a high level, the constant-current circuits  232  connect the battery  202  to the LED arrays LF-LED, LR-LED, RF-LED, RR-LED. The constant-current circuits  232  supply current from the battery  202  at a suitable time to desired ones of the LED arrays LF-LED, LR-LED, RF-LED, RR-LED, thereby blinking corresponding ones of the winker lamps LF, LR, RF, RR. Since the CPU  238  blinks the winker lamps LF, LR, RF, RR based on the different flags, which are set respectively for the left winker mode, the right winker mode, and the hazard mode, the timing at which the winker lamps LF, LR, RF, RR are blinked in the left winker mode, the right winker mode, and the hazard mode can be changed based on the flags, thereby enabling the winker lamps LF, LR, RF, RR to be blinked with high freedom. 
         [0134]    The winker lamp  10  according to the embodiment of the present invention is basically constructed as described above. Next, operations of the winker lamp  10  will be described below. 
         [0135]    According to the present embodiment, when the motorcycle  12  is being driven, the left and right winker lamps  10  are illuminated at a small light intensity as positioning lights (auxiliary lights), whereas when the rider operates the winker switch WS in the vicinity of the handle assembly  38 , based on such an operation, the winker lamp  10  on one side flashes or blinks at a large light intensity. Further, when the hazard switch HS is turned ON, the left and right winker lamps  10  are configured to blink simultaneously at a large light intensity. 
         [0136]    Accordingly, electrical power, which is controlled at a given light emission intensity and timing based on the above-described lighting operation, is supplied through the harness  130  to the LEDs  124  of the winker lamp  10  from a non-illustrated electrical system controller. As shown in  FIG. 6 , the LEDs  124 , when supplied with a predetermined amount of electrical power, emit light LL that radiates from the front surface according to the light-emitting characteristics. Light LL emitted from the LEDs  124  penetrates into the protruding portions  164  from the cavities  170  of the inner lens  128 , and is guided in a forward direction by the outer shape of the protruding portions  164 . Accordingly, preferably, the protruding portions  164  have curved shapes that enable total forward reflection of light LL emitted from the LEDs  124 . Owing thereto, light LL emitted from the LEDs  124  can easily be guided to the front surface of the inner lens  128 . Light LL having passed through the interior of the protruding portions  164 , upon reaching the lens cut region  162  on the front surface of the inner lens  128 , is diffused in the widthwise direction (lateral direction) of the vehicle by the lens surface of the lens cut region  162 . Thus, the inner lens  128  is capable of emitting a large number of light rays that proceed diagonally forward from the front surface of the lens cut region  162  in the widthwise (lateral) direction of the vehicle. Such light rays, which proceed diagonally forward in the lateral direction of the vehicle, enter into the outer side lens cut region  122   b  of the outer lens  122  and are further diffused in the vertical direction. Thus, the winker lamp  10  is capable of irradiating light of the LEDs  124  from the front surface of the outer lens  122 , which is diffused in both lateral and vertical directions of the vehicle. 
         [0137]    The harness  130  for supplying power to the LEDs  124  is connected from the grommet  150  to the board  126  through the partial space  172 . The partial space  172  is formed as a comparatively wide space, by forming the roof  166  in a flat shape having a wall thickness thinner than that of the protruding portions  164 , whereby the harness  130  can easily be arranged within the partial space  172 . 
         [0138]    Further, by arranging the harness  130  in the partial space  172 , the harness  130  is made harder to see from outside of the winker lamp  10 . More specifically, because the roof  166 , which is positioned in front of the partial space  172 , includes the lens cut region  162  on the front surface thereof, light LH 1  that is oriented in a frontward direction from the harness  130  (e.g., external light that is reflected by the harness  130 ) can be diffused in the lateral direction of the vehicle. Owing thereto, even if viewed from in front of the roof  166 , because the light LH 1  from the harness  130  is dispersed into undeterminable rays, visibility of the harness  130  can be prevented. In addition to this, in the winker lamp  10 , because light LH 1  from the harness  130  also is diffused in vertical directions by the outer side lens cut region  122   b  of the outer lens  122 , visibility of the harness  130  is prevented even further. 
         [0139]    Further, because the protruding portions  164  are arranged diagonally across the harness  130  laterally from the front of the vehicle, the harness  130  can be made less visible, in particular, with respect to visibility thereof diagonally from the outside laterally of the vehicle, as viewed from the standpoint of an oncoming vehicle or pedestrian. More specifically, concerning light LH 2  that is directed diagonally forward from the harness  130 , a portion of such rays are reflected by the curved shape of the protruding portion  164 , and then the rays progress within the protruding portion  164  in a state in which the light intensity therefrom is lowered. In addition, since the light LH 2  that is directed diagonally forward from the harness  130  reaches the lens cut region  162  in this fashion, and then is spread out in the lateral direction of the vehicle, visibility of the harness  130  is further prevented from a diagonally forward outside lateral direction of the vehicle. 
         [0140]    In the foregoing manner, with the winker lamp  10  according to the present embodiment, the harness  130 , which extends into the interior of the partial space  172 , can be made less easily visible by the inner lens  128 . Owing thereto, for example, even though the harness  130  is not covered by another member such as the vehicle body cover  74  or the like, the harness  130  can be concealed from view. Consequently, upon illumination of the winker lamp  10 , a sufficient light emission area of the winker lamp  10  can be assured, and as a result, a favorable lighting condition can be realized. Further, since it is possible to connect the harness  130  to the board  126  at a position near the LEDs  124 , the board  126  can be made small in size, and the winker lamp  10  as a whole can be reduced in scale. 
         [0141]    In the winker lamp  10 , the area of connection between the board  126  and the harness  130  may be set to overlap with the protruding portion  164  as viewed from the front. Owing thereto, the area of connection between the board  126  and the harness  130  can be hidden, in the front view, by the protruding portion  164 , thereby making the harness  130  even less easily visible from the exterior. 
         [0142]    Further, as shown in  FIG. 6 , in the case that an imaginary line Li is defined, which extends in the transverse direction of the vehicle through the welded portions of the base  120  and the inner lens  128 , the inner lens  128  is arranged such that base portion  161  sides of the protruding portions  164  are positioned nearer the outer lens  122  in relation to the imaginary line Li, and the apex sides of the protruding portions  164  are positioned nearer the board  126  in relation to the imaginary line Li. More specifically, the protruding portions  164  project by a large amount, so that the harness  130  is more difficult to be seen, in the case that the winker lamp  10  is viewed diagonally from an outer side in the transverse direction of the vehicle. 
         [0143]    Furthermore, by integrally forming the roof  166  and the protruding portions  164  of the inner lens  128 , it is unnecessary to prepare the roof  166  as a separate component apart from the inner lens  128 , and accordingly the number of components can be reduced. Therefore, assembly of the winker lamp  10  is facilitated, and production costs for the winker lamp  10  can be reduced. 
         [0144]    Although a certain preferred embodiment of the present invention has been shown and described in detail, it should be understood that various additional or modified structures or process steps could be adopted therein without departing from the scope of the invention as set forth in the appended claims. For example, the inner lens  128  may be constituted without providing the lens cut region  162  on the front surface thereof, as in the present embodiment, but rather by providing the lens cut region  162  on a back surface (rear surface) of the inner lens  128 .