Patent Publication Number: US-2009237008-A1

Title: Left/right turn indicator for vehicle

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a left/right turn indicator for a vehicle, which clearly informs oncoming vehicles and pedestrians of left or right turning of the vehicle during nighttime and the like. 
     2. Description of the Related Art 
     For the purpose of informing oncoming vehicles and pedestrians of left or right turning of a vehicle, a turn signal light, provided near a left or right headlight on the front side of the vehicle, blinks in response to the operation of a turn signal lever. However, in a dark environment such as nighttime, a headlight with high brightness is turned on on the front face side of the vehicle. Therefore, it is hard for oncoming vehicles and pedestrians to see the turn signal light provided near the headlight and blinking at low brightness, whereby it is often difficult for the oncoming vehicles and the pedestrians to clearly distinguish whether the vehicle will turn in the left or right direction. Especially, when there are vehicles behind the vehicle, it may become harder to see the turn signal light of the vehicle in front due to the light from the headlights of the vehicles behind. 
     As shown in, for example, Japanese Patent Application Laid-Open Publication No. 5-229384, there has been known a left/right turn clarifying device, which has the conventional turn signal lights and one or more light emitting bodies provided on the left and right outer sides of a vehicle body. When a turn signal switch is operated for a left or right turn operation of the vehicle, the left or right turn signal is turned on, and, at the same time, the left or right light emitting body is also turned on. However, in this left/right turn clarifying device, since the left and right light emitting bodies are provided at a distance from the left and right turn signal lights, the relation between the light emitting bodies and the turn signal lights is difficult to understand, leading to confusion. Further, since one or more light emitting bodies should be provided on the left and right outer sides of a vehicle, the mounting cost is increased. 
     SUMMARY OF THE INVENTION 
     The present invention is made to solve the above problems, and its object is to provide a left/right turn indicator for a vehicle, which can easily and clearly inform oncoming vehicles and pedestrians of left or right turning state of the vehicle in a dark environment such as nighttime. 
     In order to achieve the above object, the present invention has the following features in constitution. In the left/right turn indicator for a vehicle of the present invention, left and right headlights are provided on left and right sides of a front part of the vehicle. In response to a left turn operation of a turn signal lever provided in the vehicle, the left headlight is changed from a normal lighting state to left turn indication. In response to a right turn operation of the turn signal lever, the right headlight is changed from a normal lighting state to right turn indication. The left turn indication corresponds to turning off of the left headlight or rendering the brightness of the left headlight smaller than the brightness in the normal lighting state. The right turn indication corresponds to turning off of the right headlight or rendering the brightness of the right headlight smaller than the brightness in the normal lighting state. 
     More specifically, the left/right turn indicator for a vehicle of the present invention includes a headlight driving unit, a left/right turn detection unit, and a lighting control device. The headlight driving unit turns on and off left and right headlights provided on left and right sides of the front part of the vehicle. The left/right turn detection unit detects left or right turn operation of a turn signal lever provided in the vehicle. The lighting control device controls the operation of the headlight driving unit. Based on the control from the lighting control device, the headlight driving unit operates the left headlight so that the left headlight performs left turn indication in response to a left turn detection result from the left/right turn detection unit, and the headlight driving unit operates the right headlight so that the right headlight performs right turn indication in response to a right turn detection result from the left/right turn detection unit. The left turn indication executed by the headlight driving unit corresponds to turning off of the left headlight or rendering the lighting brightness of the left headlight smaller than the brightness in the normal lighting state. The right turn indication executed by the headlight driving unit corresponds to turning off of the right headlight or rendering the lighting brightness of the right headlight smaller than the brightness in the normal lighting state. 
     The left and right headlights respectively may have a main light and a small light. In this case, while the main light is turned off, the small light is turned on or the brightness is smaller than the brightness in the normal lighting. Alternatively, while the brightness of the main light is smaller than the brightness in the normal lighting, the small light is turned on or the brightness is smaller than the brightness in the normal lighting. These patterns are included in the present invention. 
     According to the present invention constituted as described above, when the left and right headlights provided on the left and right sides of the front part of the vehicle are turned on, the left headlight being turned on is turned off or the brightness is smaller than the brightness in the normal lighting in response to the left turn operation of the turn signal lever provided in the vehicle. When the right turn operation of the turn signal lever is performed, the right headlight being turned on is turned off or the brightness is smaller than the brightness in the normal lighting in response to the operation. According to this constitution, blinking of the left and right turn signal lights is relatively clearly recognized. Consequently, it is convenient because, in a dark environment such as nighttime where the headlights are turned on, oncoming vehicles and pedestrians can clearly recognize the change in the headlight from the normal lighting state to the left or right turn indication, and thus can surely know the left or right turning of the vehicle, and, at the same time, it is very useful in view of road safety. Further, according to the present invention, the existing headlight can be used as it is, whereby the left and right turn indications can be performed at low cost by using the left and right headlights. 
     Further, according to the present invention, in response to the left or right turn operation of the turn signal lever, the left or right turn indication can be selected, or the left or right turn indication cannot be selected. According to this constitution, by using indication selection means, it is possible to select whether the left or right headlight is caused to perform the left or right turn indication by means of the headlight driving unit or the left or right headlight is kept in the normal lighting state, in accordance with road conditions, driving time, and so on. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a vehicle according to an embodiment of the present invention; 
         FIG. 2  is a schematic perspective view around a steering of the vehicle; 
         FIG. 3  is a block diagram showing a circuit configuration of a left/right turn indicator of the vehicle; 
         FIG. 4  is a flow chart showing a “turn signal control program” executed by a lighting control device of the left/right turn indicator; and 
         FIG. 5  is a flow chart showing a “headlight control program” executed by the lighting control device of the left/right turn indicator. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, an embodiment of the present invention will be described using the drawings.  FIG. 1  is a perspective view of a vehicle using a left/right turn indicator according to the embodiment.  FIG. 2  is a perspective view around a steering of the vehicle.  FIG. 3  is a block diagram of the left/right turn indicator. A left/right turn indicator  30  includes a headlight driving unit  32 , a turn signal light driving unit  33 , a left turn switch  21 , a right turn switch  22 , and a lighting control device  31 , etc. The headlight driving unit  32  turns on or off left and right headlights  12  and  13  respectively provided on the left and right sides of the front part of a vehicle  10 . The turn signal light driving unit  33  turns on or off left and right turn signal lights  14  and  15 . The left and right turn switches  21  and  22  are left/right turn detection units for detecting left and right turn operations of a turn signal lever  19  provided in the vehicle  10 . When the left and right turn switches  21  and  22  detect the left turn operation, the lighting control device  31  causes the headlight driving unit  32  to change the left headlight  12  from a normal lighting state to left turn indication in accordance with the detection result. Meanwhile, when the right turn operation is detected, the lighting control device  31  causes the headlight driving unit  32  to change the right headlight  13  from a normal lighting state to right turn indication in accordance with the detection result. 
     The left and right headlights  12  and  13  are constituted of left and right main lights  12   a  and  13   a  with large size, provided on the upper side, and left and right small lights  12   b  and  13   b  provided on the lower side. The left and right turn signal lights  14  and  15  are arranged adjacent to the outside in the lateral direction of each of the main lights  12   a  and  13   a . The turn signal lever  19  protruding from a column  18  of a steering  17  is operated to be bent upward from a neutral position to turn on the left turn switch  21  which is the left turn detection unit. Meanwhile, the turn signal lever  19  is operated to be bent downward to turn on the right turn switch  22  which is the right turn detection unit. Further, a headlight operation part  23  is provided at the top of the turn signal lever  19 . The headlight operation part  23  is operated and rotated to thereby turn on or off a headlight switch  24 . By virtue of the rotating operation of the headlight operation part  23 , the main lights  12   a  and  13   a  can be switched into two states of a lighting state with normal brightness (low light) and a lighting state with higher brightness than normal (high light). The small lights  12   b  and  13   b  remain single brightness. 
     A lighting state selection lever  25  is provided on the lower side of the headlight operation part  23  of the turn signal lever  19 . The lighting state selection lever  25  switches turning on/off of a selection switch  26  used for selecting whether or not the left and right headlights  12  and  13  are caused to perform left or right turn indication. The lighting state selection lever  25  and the selection switch  26  constitute indication selection means. When the lighting state selection lever  25  is at the initial position, the selection switch  26  is turned off, and each of the headlights  12  and  13  are in a normal lighting state. The lighting state selection lever  25  is rotated clockwise, whereby the selection switch  26  is turned on, and the left and right headlights  12  and  13  are caused to perform the left or right turn indication in response to the left or right turn operation of the turn signal lever  19 . The vehicle  10  includes therein the left turn switch  21 , the right turn switch  22 , the headlight switch  24 , the selection switch  26 , the lighting control device  31 , the headlight driving unit  32 , and the turn signal light driving unit  33 . These components constitute the left/right turn indicator  30 . The lighting control device  31  performs lighting control of the left and right headlights  12  and  13  and the left and right turn signal lights  14  and  15 . 
     The lighting control device  31  has a microcomputer including a CPU, a ROM, a RAM, an I/O,etc. As shown in  FIG. 3 , the lighting control device  31  cooperates with the left turn switch  21 , the right turn switch  22 , the headlight switch  24 , the selection switch  26 , the headlight driving unit  32 , and the turn signal light driving unit  33  in executing a “turn signal control program” shown in  FIG. 4  and a “headlight lighting control program” shown in  FIG. 5 . In these programs, S represents a step, Y represents a determination of “YES”, and N represents a determination of “NO”. The lighting control device  31  is connected on the input side to the left turn switch  21 , the right turn switch  22 , the headlight switch  24 , and the selection switch  26 . Meanwhile, the lighting control device  31  is connected on the output side to the headlight driving unit  32  for driving the left and right headlights  12  and  13  and the turn signal light driving unit  33  for driving the left and right turn signal lights  14  and  15 . 
     Next, the operation of the above embodiment will be described. 
     When a starter switch of the vehicle  10  is turned on, the lighting control device  31  starts the execution of the “turn signal control program” shown in  FIG. 4  at step  40  (hereinafter indicated as S 40 ) and, at the same time, starts the execution of the “headlight lighting control program” shown in  FIG. 5  at S 70 . In the driving in a dark environment such as nighttime, the headlight switch  24  is turned on by virtue of the rotating operation of the headlight operation part  23 . The left and right main lights  12   a  and  13   a  are made into the lighting state with normal brightness, and the left and right small lights  12   b  and  13   b  are turned on (S 71  and S 72 ). 
     At the start of the execution of the “turn signal control program”, left and right turn signal switch flags LSF and RSF are respectively set to “0” (S 41 ). When the lighting state selection lever  25  provided in the turn signal lever  19  is rotated clockwise, the selection switch  26  is turned on (S 42 ), so that the left and right headlights  12  and  13  are caused to perform the left or right turn indication in response to the left or right turn operation of the turn signal lever  19 . At this time, the turn signal lever  19  is not operated yet, and therefore, the left and right turn switches  21  and  22  are turned off (S 43  and S 49 ). When the selection switch  26  is turned on and the left and right turn switches  21  and  22  are turned off, the left and right turn signal switch flags LSF and RSF are set to “0”. When the selection switch  26  is turned on and the left and right turn switches  21  and  22  are turned on, the left and right turn signal switch flags LSF and RSF are set to “1”. 
     In the execution of the “headlight control program”, when the left and right headlights  12  and  13  are turned on, the left and right turn signal switch flags LSF and RSF are read (S 72  and S 73 ). The left and right main lights  12   a  and  13   a  are made into the lighting state with normal brightness, and the left and right small lights  12   b  and  13   b  are turned on. However, since the left and right turn signal switch flags LSF and RSF are set to “0” at this time, the judgments in S 74  and S 75  is “NO”, whereby the lighting state is maintained. 
     When the left turn operation of the turn signal lever  19  is performed, the left turn switch  21  is turned on, and thus the left turn signal light  14  is turned on, whereby the left turn signal switch flag LSF is changed to “1” (S 43 , S 44 , and S 45 ). In response to this, the left main light  12   a  is turned off by the headlight driving unit  32 , and this state is maintained until the left turn operation is released (S 74 , S 77 , and S 78 ). Incidentally, the left small light  12   b  remains turned on. When the left turn operation of the turn signal lever  19  is released, the left turn switch  21  is turned off, and thus the left turn signal light  14  is turned off, whereby the left turn signal switch flag LSF is changed to “0” (S 46 , S 47 , and S 48 ). In response to this, the left main light  12   a  is turned on by the headlight driving unit  32  (S 79 ), and the processing from S 74  to S 76  is repeated until the headlight switch  24  is turned off to turn off the headlights  12  and  13  (S 76 ). 
     When the right turn operation of the turn signal lever  19  is performed, the right turn switch  22  is turned on, and thus the right turn signal light  15  is turned on, whereby the right turn signal switch flag RSF is changed to “1” (S 43 , S 50 , and S 51 ). In response to this, the right main light  13   a  is turned off by the headlight driving unit  32 , and this state is maintained until the right turn operation is released (S 75 , S 80 , and S 81 ). Incidentally, the right small light  13   b  remains turned on. When the right turn operation of the turn signal lever  19  is released, the right turn switch  22  is turned off, and thus the right turn signal light  15  is turned on, whereby the right turn signal switch flag RSF is changed to “0” (S 52 , S 53 , and S 54 ). In response to this, the right main light  13   a  is turned on by the head light driving unit  32  (S 81  and S 82 ), and the processing from S 74  to S 79  is repeated until the headlight switch  24  is turned off to turn off the headlights  12  and  13  (S 76 ). When the headlight switch  24  is turned off at, for example, the end of the driving of the vehicle, the headlights  12  and  13  are turned off (S 76 , S 83 , and S 84 ). 
     As described above, according to the present embodiment, when the left and right headlights  12  and  13  provided on the left and right sides of the front part of the vehicle  10  are turned on, the turn signal lever  19  provided in the vehicle  10  is operated for a left turn operation, and in response to this operation, the left turn signal light  14  is turned on, and, at the same time, the left main light  12   a  is made into a turned-off state corresponding to the left turn indication. Meanwhile, when the right turn operation of the turn signal lever  19  is performed, the right turn signal light  15  is turned on, and, at the same time, the right main light  13   a  is made into a turned-off state corresponding to the right turn indication, in response to the operation. According to this constitution, the lighting states of the left and right turn signal lights  14  and  15  can be relatively clearly recognized. Consequently, in this embodiment, it is convenient because, in the dark environment such as nighttime where the left and right headlights  12  and  13  are made into the normal lighting state, oncoming vehicles and pedestrians can clearly recognize that the left or right main light  12   a  or  13   a  is changed from the normal lighting state to the turned-off state corresponding to the left or right turn indication and thus can surely know the left or right turning of the vehicle  10 , and, at the same time, it is very useful in view of road safety. Further, according to this embodiment, the existing headlight can be used as it is, whereby the left and right turn indications can be performed at low cost by using the left and right headlights  12  and  13 . 
     In this embodiment, in the case where the left and right headlights  12  and  13  need not be caused to perform the left or right turn indication, and may be kept in the normal lighting state, the lighting state selection lever  25  is not operated, whereby the selection switch  26  remains turned off (S 42 ). Thus, when the left turn operation of the turn signal lever  19  is performed, the left turn switch  21  is turned on, and thus the left turn signal light  14  is turned on; however, the left turn signal switch flag LSF is maintained at “0” (S 55  and S 56 ). According to this constitution, the left headlight  12  remains turned on without being affected (S 74 , S 75 , and S 76 ). When the left turn operation of the turn signal lever  19  is released, the left turn switch  21  is turned off, and thus the left turn signal light  14  is turned off; however, the left turn signal switch flag LSF is maintained at “0”, whereby the left headlight  12  remains turned on without being affected (S 74 , S 75 , and S 76 ). Also when the right turn operation of the turn signal lever  19  is performed, only the turning on and off of the right turn signal light  15  are performed as in the left turn operation. For this reason, the lighting states of the left and right headlights  12  and  13  are not affected. 
     In a first variation of the above embodiment, the brightness in the left and right turn indications may be rendered smaller than the brightness in the normal lighting state instead of the turning off of the left and right main lights  12   a  and  13   a . According to this constitution, when the left turn operation of the turn signal lever  19  provided in the vehicle is performed, the brightness of the left main light  12   a  being turned on is, in response to this operation, clearly rendered smaller than normal brightness. Meanwhile, when the right turn operation of the turn signal lever  19  is performed, the brightness of the right main light  13   a  being turned on is rendered small in response to this operation. Thus, in the first variation, in the dark environment such as nighttime where the left and right headlights  12  and  13  are made into the normal lighting state, the brightness of the left and right main lights  12   a  and  13   a , which are being turned on, is rendered small. This enables whereby oncoming vehicles and pedestrians to surely know the left or right turning of the vehicle. 
     In a second variation, with regard to the left and right turn indications, the left and right main lights  12   a  and  13   a  may be kept in a normal lighting state instead of being turned off, while the left and right small lights  12   b  and  13   b  may be turned off, or the brightness of the left and right small lights  12   b  and  13   b  may be rendered smaller than the brightness in the normal lighting state. According to this constitution, when the left turn operation of the turn signal lever  19  provided in the vehicle is performed, the left small light  12   b  being turned on is turned off or the brightness of the left small light  12   b  is clearly rendered smaller than normal brightness, in response to the operation. Meanwhile, when the right turn operation is performed, the right small right  13   b  being turned on is turned off or the brightness of the right small light  13   b  is rendered small, in response to this operation. Thus, also in the second variation, in the dark environment such as nighttime where the left and right headlights  12  and  13  are made into the normal lighting state, the left and right small lights  12   b  and  13   b , which are being turned on, are turned off, or the brightness is rendered small. This enables oncoming vehicles and pedestrians to surely know the left or right turning of the vehicle. 
     Further, as a reference example of the present invention, the left headlight  12  or the right headlight  13  of red, green, or other colors may be turned on in the left or right turn indication. In this case, lamps emitting different colors are required to be provided in the left and right headlights  12  and  13 . According to this reference example, when the left turn operation of the turn signal lever  19  provided in the vehicle is performed, the left headlight  12  being turned on is changed into a different color in response to this operation. Meanwhile, when the right turn operation of the turn signal lever  19  is performed, the right headlight  13  being turned on is changed into a different color in response to this operation. Thus, in the dark environment such as nighttime where the left and right headlights  12  and  13  are made into the normal lighting state, the headlights  12  and  13  being turned on are changed into a different color, whereby oncoming vehicles and pedestrians can surely know the left or right turning of the vehicle. 
     In the present embodiment and variations, the selection switch  26  is turned on or off by the operation of the lighting state selection lever  25 , thereby to select whether or not the left headlight  12  or the right headlight  13  is caused to perform the left or right turn indication. However, instead of this, it is possible to cause the left and right headlights  12  and  13  to always perform the left and right turn indications independently of the turning on and off of the selection switch  26 . In this case, omission of S 42 , S 55  to S 61  of the “turn signal control program” shown in  FIG. 4  allows the left and right headlights  12  and  13  to always perform the left and right turn indications. According to this constitution, the lighting state selection lever  25  and the selection switch  26  can be omitted, and thus, the structure of the control device can be simplified. This can realize the left and right turn indications performed by the left and right headlights  12  and  13  at low cost. The left/right turn indicator and each component of the vehicle shown in the above embodiment are merely one example. The present invention can be variously modified and practiced without departing from the scope of the present invention. 
     Further, according to the present invention, a pair of headlights provided on the left and right front sides of a vehicle is used as it is. In response to left and right turn operations of a turn signal lever, the left headlight is changed from the normal lighting state to the left turn indication, and the right headlight is changed from a normal lighting state to right turn indication. Accordingly, it is convenient because, in a dark environment such as nighttime where the headlights are turned on, oncoming vehicles and pedestrians can surly know the left or right turning of the vehicle based on the change in the headlight from the normal lighting state to the left or right turn indication, and, at the same time, it is very useful in view of road safety.