Patent Publication Number: US-2020282950-A1

Title: Vehicle operation detection device

Description:
1. FIELD 
     The following description relates to a vehicle operation detection device that detects an opening-closing operation for the door of a vehicle. 
     2. DESCRIPTION OF RELATED ART 
     Japanese Laid-Open Patent Publication No. 2010-254262 describes a typical example of a vehicle operation detection device. The vehicle operation detection device includes the electrode of a capacitance sensor arranged in the door of a vehicle. When the electrode detects the motion of the user placing a part of the body such as a hand over the door, the door is locked or unlocked. That is, the motion of the user moving a part of the body toward the electrode is a locking-unlocking operation of locking or unlocking the door. 
     In another typical vehicle operation detection device, the same motion is the opening-closing operation for the door. 
     A further typical vehicle operation detection device includes electrodes laid out in the door in an opening-closing direction of the door. In this case, when the user moves a part of the body toward the electrodes and the motion of moving the part of the body in the opening-closing direction is detected, the door opens and closes. That is, the motion of moving a part of the body toward the electrodes and moving the part of the body in the opening-closing direction is the opening-closing operation for the door. 
     In a case where the motion of the user moving a part of the body toward the electrodes and moving the part of the body in the opening-closing direction is the opening-closing operation for the door, for example, the user may be uncertain whether he or she is operating correctly. This will worsen the usability. 
     SUMMARY 
     It is an objective of the present disclosure to provide a vehicle operation detection device that simplifies how to perform an opening-closing operation for the door of a vehicle. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     According to an aspect of the present disclosure, a vehicle operation detection device is provided. The vehicle operation detection device includes sensors laid out in a vehicle along an axis in an opening-closing direction of a door of the vehicle and configured to individually output a detection signal that changes when a part of a body of a user moves toward the sensors. When the user moves the part of the body toward the sensors and a motion of moving the part of the body along the axis is detected, the sensors detect an opening-closing operation for the door. The vehicle operation detection device further includes light-emitting members laid out in the vehicle along the axis in the opening-closing direction and an operation direction indicator configured to drive the light-emitting members in sequence in a first direction extending along the axis and corresponding to an opening direction in a fully-closed state of the door and configured to drive the light-emitting members in sequence in a second direction extending along the axis and corresponding to a closing direction in a fully-open state of the door. 
     According to an aspect of the present disclosure, a vehicle operation detection device includes a set of sensors laid out in a vehicle in a first direction corresponding to an opening direction of a door of the vehicle. Each of the sensors is configured to detect a part of a body of a user. The vehicle operation detection device is configured to detect an opening operation for the door when the user moves the part of the body toward one of the sensors and moves the part of the body in the first direction, and detect a closing operation for the door when the user moves the part of the body toward another one of the sensors and moves the part of the body in a second direction that is opposite to the first direction. The vehicle operation detection device also includes a set of light-emitting members laid out in the vehicle in the first direction and processing circuitry configured to drive the light-emitting members in sequence in the first direction when the door is in a fully-closed state and configured to drive the light-emitting members in sequence in the second direction when the door is in a fully-open state. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the side structure of a vehicle to which a vehicle operation detection device according to an embodiment is applied. 
         FIG. 2A  is a front view showing the structure of the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 2B  is a cross-sectional view showing the structure of the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 3  is a block diagram showing the electric configuration of the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 4A  is a timing diagram illustrating a mode of detecting the operation of the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 4B  is a timing diagram illustrating a mode of detecting the operation of the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 5  is a front view illustrating a mode of driving the LEDs when ID authentication is established in a fully-closed state of the door in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 6  is a front view illustrating a mode of driving the LEDs when the reception of the motion of the opening operation for the door is completed in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 7  is a front view illustrating a mode of driving the LEDs when the reception of rear swiping is completed in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 8  is a front view illustrating a mode of driving the LEDs when ID authentication is established in a fully-open state of the door in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 9  is a front view illustrating a mode of driving the LEDs when the reception of the motion of the closing operation for the door is completed in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 10  is a front view illustrating a mode of driving the LEDs when the reception of front swiping is completed in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 11  is a flowchart illustrating a mode of driving the LEDs in the vehicle operation detection device of the embodiment in  FIG. 1 . 
         FIG. 12  is a perspective view showing the rear structure of a vehicle to which a vehicle operation detection device according to a modification is applied. 
         FIG. 13  is a front view showing the structure of the vehicle operation detection device of the modification in  FIG. 12 . 
         FIG. 14  is a side view showing the structure of the vehicle to which a vehicle operation detection device according to a modification is applied. 
         FIG. 15  is a cross-sectional view showing the structure of a vehicle operation detection device according to a modification. 
         FIG. 16  is a cross-sectional view showing the structure of a vehicle operation detection device according to a modification. 
     
    
    
     Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     This description provides a comprehensive understanding of the methods, apparatuses, and/or systems described. Modifications and equivalents of the methods, apparatuses, and/or systems described are apparent to one of ordinary skill in the art. Sequences of operations are exemplary, and may be changed as apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Descriptions of functions and constructions that are well known to one of ordinary skill in the art may be omitted. 
     Exemplary embodiments may have different forms, and are not limited to the examples described. However, the examples described are thorough and complete, and convey the full scope of the disclosure to one of ordinary skill in the art. 
     A vehicle operation detection device according to an embodiment will now be described. 
       FIG. 1  shows a vehicle  1 , such as an automobile, including a body  2 . The side part of the body  2  has an opening  2   a . Further, the side part of the body  2  incorporates a sliding door  3 . When moving in the front-rear direction, the sliding door  3  opens and closes the opening  2   a . The sliding door  3  is arranged on the side part of the vehicle  1  and moves in the horizontal direction. The sliding door  3  includes a door body  4  and a window glass  5 . The door body  4  is the lower portion of the sliding door  3  and has a substantially hollow structure. The window glass  5  moves in the up-down direction from the door body  4 . The door body  4  includes a door lock  6  that locks and unlocks the sliding door  3  that is in a fully-closed state. 
     The sliding door  3  includes a door driving unit  11  located, for example, in the door body  4 . The door driving unit  11  mainly includes an electric drive source such as an electric motor. The door driving unit  11  is mechanically cooperated with the body  2  by a door driving mechanism to open and close the sliding door  3 . Further, the sliding door  3  includes a door lock driving unit  12  located, for example, adjacent to the door lock  6 . The door lock driving unit  12  mainly includes an electric drive source such as an electric motor. The door lock driving unit  12  is mechanically cooperated with the door lock  6  by a door driving mechanism to lock and unlock the door lock  6 . 
     The door driving unit  11  and the door lock driving unit  12  are both electrically connected to a door electronic control unit (ECU)  10  including, for example, a microcontroller unit (MCU). Further, door driving unit  11  and the door lock driving unit  12  are both individually driven by the door ECU  10 . 
     The window glass  5  includes a substantially elongated sensor unit  30  located immediately above the door body  4  when the window glass  5  is closed. The sensor unit  30  adheres to the inner surface of the window glass  5  of the vehicle  1 . 
     Referring to  FIGS. 2A and 2B , the sensor unit  30  includes a case  31  serving as a housing of the sensor unit  30 . The case  31  includes a base  32  and a cover  33 . The base  32  is formed by, for example, an iron plate and is substantially elongated. The cover  33  is made of, for example, a plastic material and has a lid and the form of a substantially rectangular tube. The cover  33  is coupled to the base  32  such that the cover  33  is closer to the window glass  5  than the base  32 . This defines an accommodation space between the cover  33  and the base  32 . 
     The case  31  accommodates a first electrode  34 , a second electrode  35 , and a third electrode  36 . Each of the first electrode  34 , the second electrode  35 , and the third electrode  36  is the electrode of a capacitance sensor. The first electrode  34 , the second electrode  35 , and the third electrode  36  are laid out so as to be spaced apart from one another in the front-rear direction, which corresponds to an axis in the opening-closing direction of the door. That is, the first electrode  34 , the second electrode  35 , and the third electrode  36  correspond to sensors laid out in the vehicle along the axis in the opening-closing direction of the door of the vehicle  1 . The shapes of the first to third electrodes  34  to  36  are substantially the same. Each of the first to third electrodes  34  to  36  changes in capacitance when a part of the body of the user such as a hand H moves toward the surface of the window glass  5  in the vicinity of the sensor unit  30 . That is, the capacitance of each of the first to third electrodes  34  to  36  increases as a part of the body of the user becomes closer and decreases as the part of the body of the user becomes farther away. 
     Further, the case  31  includes light-emitting diodes (LEDs)  37  below the first electrode  34 , the second electrode  35 , and the third electrode  36 . The LEDs  37  are laid out so as to be spaced apart from one another in the front-rear direction, which corresponds to the axis in the opening-closing direction of the door. That is, the LEDs  37  correspond to light-emitting members laid out in the vehicle  1  along the axis in the opening-closing direction. The number of the LEDs  37  is a multiple of the number of each of the first to third electrodes  34  to  36  such that the same number of the LEDs  37  are provided below each of the first to third electrodes  34  to  36 . More specifically, one electrode includes six LEDs  37 . In addition, the case  31  accommodates a light guide  38  such that the light guide  38  is closer to the window glass  5  than the LEDs  37 . The light guide  38  guides the light of the LEDs  37  toward the window glass  5 . The cover  33  includes a through-hole  33   a  opposed to the light guide  38 . 
     The electrical configuration of the sensor unit  30  will now be described. 
     As shown in  FIG. 3 , the sensor unit  30  includes a capacitance detection circuit  41 , a drive circuit  42 , and a control circuit  43 . The capacitance detection circuit  41  is individually connected to the first to third electrodes  34  to  36 . The drive circuit  42  is individually connected to the LEDs  37 . The control circuit  43  serves as an operation direction indicator  43   a  connected to the capacitance detection circuit  41  and the drive circuit  42 . Further, the sensor unit  30  is connected to the door ECU  10  in the control circuit  43 . 
     Each of the first to third electrodes  34  to  36  outputs, to the capacitance detection circuit  41 , detection signals Se 1 , Se 2 , and Se 3  at the voltage levels corresponding to the capacitance of the electrodes. The capacitance detection circuit  41  generates detection data D 1 , D 2 , and D 3 , into which the detection signals Se 1  to Se 3  are respectively converted from analogue to digital, and outputs the detection data D 1 , D 2 , and D 3  to the control circuit  43 . Needless to say, the detection data D 1  to D 3  change when a part of the body of the user moves toward the surface of the window glass  5  in the vicinity of the sensor unit  30 . 
     The control circuit  43  uses the detection data D 1  to D 3  to detect various types of operation of opening and closing the sliding door  3 . In a normal operation of the present embodiment, the motion of the user moving a part of the body toward the surface of the window glass  5  in the vicinity of the sensor unit  30  indicates that the opening-closing operation of the sliding door  3  has been started. At this time, as shown in  FIG. 4A , as the detection data D 1  to D 3  vary, the magnitude relationship with a predetermined threshold value Dth reverses. As the magnitude relationship between the detection data D 1  to D 3  and the threshold value Dth reverses, the control circuit  43  detects that the opening-closing operation of the sliding door  3  has been started. 
     The motion of the user moving in the rearward direction by moving a part of the body toward the surface of the window glass  5  in the vicinity of the sensor unit  30  may be referred to as rear swiping. The rearward direction corresponds to a first direction, which is the axis corresponding to the opening direction of the door. In a normal operation of the present embodiment, rear swiping represents an opening operation for the sliding door  3  and an unlocking operation for the door lock  6  corresponding to the opening operation. At this time, as shown in  FIG. 4B , as the detection data D 1  to D 3  vary in this sequence, the magnitude relationship with the threshold value Dth reverses. As the magnitude relationship of the detection data D 1  to D 3  with the threshold value Dth reverses in this sequence, the control circuit  43  detects, for example, the opening operation for the sliding door  3 . 
     The motion of the user moving in the frontward direction by moving a part of the body toward the surface of the window glass  5  in the vicinity of the sensor unit  30  may be referred to as front swiping. The frontward direction corresponds to a second direction, which is the axis corresponding to the closing direction of the door. In a normal operation of the present embodiment, front swiping represents a closing operation for the sliding door  3  and a locking operation for the door lock  6  corresponding to the opening operation. At this time, as the detection data D 1  to D 3  vary in reverse sequence, the magnitude relationship with the threshold value Dth reverses. That is, as the detection data D 3 , the detection data D 2 , and the detection data D 1  vary in sequence, the magnitude relationship with the threshold value Dth reverses. As the magnitude relationship of the detection data D 1  to D 3  with the threshold value Dth reverses in reverse sequence, the control circuit  43  detects, for example, the closing operation for the sliding door  3 . 
     As shown in  FIG. 3 , the control circuit  43  outputs to the door ECU  10  an operation signal S indicating the detection result of the opening-closing operation for the sliding door  3 . 
     Further, the control circuit  43  generates a control signal C corresponding to an information signal Im from the detection data D 1  to D 3  and the door ECU  10  and outputs the control signal C to the drive circuit  42 . The drive circuit  42  drives the LEDs  37  in response to the control signal C. 
     The door ECU  10  is connected to an onboard unit  21  mounted in the body  2 . The onboard unit  21  corresponds to a communication member. The onboard unit  21  functions as a wireless communication system with a portable unit  26 , which serves as an electronic key carried by the user. The onboard unit  21  executes ID authentication by verifying an ID code through bilateral communication with the portable unit  26 . The onboard unit  21  transmits to the door ECU  10  a signal indicating the result of the ID authentication. 
     When the signal from the onboard unit  21  indicates that ID authentication is established, upon receipt of the operation signal S indicating the opening operation or the like for the sliding door  3  from the control circuit  43 , the door ECU  10  drives the door lock driving unit  12  to unlock the door lock  6  and drives the door driving unit  11  to open the sliding door  3 . When the signal from the onboard unit  21  indicates that ID authentication is established, upon receipt of the operation signal S indicating the closing operation or the like for the sliding door  3  from the control circuit  43 , the door ECU  10  drives the door lock driving unit  12  to lock the door lock  6  and drives the door driving unit  11  to close the sliding door  3 . 
     The door ECU  10  is connected to a position sensor  22  that detects an opening-closing position of the sliding door  3 . The door ECU  10  uses the detection result of the position sensor  22  to detect the opening-closing position of the sliding door  3 . 
     The door ECU  10  generates the information signal Im, which indicates the establishment result of ID authentication or the opening-closing position of the sliding door  3 , and outputs the information signal Im to the control circuit  43 . 
     The modes of driving the LEDs  37  in the present embodiment will now be described. In  FIGS. 5 to 10 , the LEDs  37  with radial lines indicate that the LEDs  37  are on or blinking. 
     First, when ID authentication is established in the fully-closed state of the sliding door  3 , as shown in  FIG. 5 , the control circuit  43  drives the six LEDs  37  located immediately below the first electrode  34  in correspondence with the position of the first electrode  34 , toward which the user should initially move a part of the body, such that the LEDs  37  turn on or blink (the first electrode  34  corresponds to a sensor toward which the user should initially move a part of the body). In other words, the control circuit  43  drives the six LEDs  37  located immediately below the control circuit  43  in correspondence with the detection range of the first electrode  34  that is currently detecting capacitance such that the six LEDs  37  turn on or blink. This is for the user to understand the position of the first electrode  34 , toward which the user should initially move a part of the body, when the opening operation for the sliding door  3  is performed. Also, this is for the user to understand that the motion of the opening operation for the sliding door  3  is under reception. 
     Next, when the reception of the above-described motion of the opening operation for the sliding door  3  is completed, as shown in  FIG. 6 , the control circuit  43  drives the LEDs  37  to turn on or blink in sequence in a rearward direction Rr. The rearward direction Rr corresponds to the first direction, which is the axis corresponding to the opening direction of the door. That is, the control circuit  43  drives the LEDs  37  in sequence in the rearward direction Rr from the frontmost one of the six LEDs  37  located immediately below the first electrode  34  to the rearmost one of the six LEDs  37  located immediately below the third electrode  36 . This causes the LEDs  37  to turn on or blink in sequence in the rearward direction Rr in a flowing manner. In such a manner, in the fully-closed state of the sliding door  3 , after the control circuit  43  drives the LEDs  37  located immediately below the first electrode  34  and the first electrode  34  detects a part of the body, the control circuit  43  drives the LEDs  37  located immediately below the second electrode  35 . In  FIG. 6 , the blank arrow indicates a mode in which the LEDs  37  turn on or blink in sequence in the rearward direction Rr. This is for the user to easily remember that the opening operation for the sliding door  3  is the motion of moving a part of the body toward the first to third electrodes  34  to  36  and moving the part of the body in the rearward direction Rr, that is, rear swiping. Also, this is for the user to understand where rear swiping starts and ends. Further, this is for the user to understand that rear swiping is under reception. 
     If there is a limit to the speed of rear swiping, the speed of switching the LEDs  37  may be set in correspondence with the rear swiping speed. This allows the user to understand a limit to rear swiping by visually recognizing the LEDs  37 . 
     Subsequently, it is assumed that the reception of rear swiping is completed. At this time, as shown in  FIG. 7 , the control circuit  43  drives the LEDs  37  located immediately below the first to third electrodes  34  to  36  such that all the LEDs  37  turn on or blink. This is for the user to understand that the reception of rear swiping is completed. 
     When ID authentication is established in the fully-closed state of the sliding door  3 , as shown in  FIG. 8 , the control circuit  43  drives the six LEDs  37  located immediately below the third electrode  36  in correspondence with the position of the third electrode  36 , toward which the user should initially move a part of the body, such that the LEDs  37  turn on or blink (the third electrode  36  corresponds to the sensor toward which the user should initially move a part of the body). In other words, the control circuit  43  drives the six LEDs  37  located immediately below the control circuit  43  in correspondence with the detection range of the third electrode  36  that is currently detecting capacitance such that the six LEDs  37  turn on or blink. This is for the user to understand the position of the third electrode  36 , toward which the user should initially move a part of the body, when the closing operation for the sliding door  3  is performed. Also, this is for the user to understand that the motion of the closing operation for the sliding door  3  is under reception. 
     Next, when the reception of the above-described motion of the closing operation for the sliding door  3  is completed, as shown in  FIG. 9 , the control circuit  43  drives the LEDs  37  to turn on or blink in sequence in a frontward direction Fr. The frontward direction Fr corresponds to a second direction, which is the axis corresponding to the closing direction of the door. That is, the control circuit  43  drives the LEDs  37  in sequence in the frontward direction Fr from the rearmost one of the six LEDs  37  located immediately below the third electrode  36  to the frontmost one of the six LEDs  37  located immediately below the first electrode  34 . This causes the LEDs  37  to turn on or blink in sequence in the frontward direction Fr in a flowing manner. In such a manner, in the fully-open state of the sliding door  3 , after the control circuit  43  drives the LEDs  37  located immediately below the third electrode  36  and the third electrode  36  detects a part of the body, the control circuit  43  drives the LEDs  37  located immediately below the second electrode  35 . In  FIG. 9 , the blank arrow indicates a mode in which the LEDs  37  turn on or blink in sequence in the frontward direction Fr. This is for the user to easily remember that the closing operation for the sliding door  3  is the motion of moving a part of the body toward the first to third electrodes  34  to  36  and moving the part of the body in the frontward direction Fr, that is, front swiping. Also, this is for the user to understand where front swiping starts and ends. Further, this is for the user to understand that front swiping is under reception. 
     If there is a limit to the speed of front swiping, the speed of switching the LEDs  37  may be set in correspondence with the front swiping speed. This allows the user to understand a limit to front swiping by visually recognizing the LEDs  37 . 
     Then, when the reception of front swiping is completed, in the same manner as rear swiping, the control circuit  43  drives the LEDs  37  located immediately below the first to third electrodes  34  to  36  such that all the LEDs  37  turn on or blink. This is for the user to understand that the reception of front swiping is completed. 
     Each of the two LEDs  37  on the middle of the six LEDs  37  located immediately below the second electrode  35  corresponds to a middle light-emitting member located on the middle along the axis and may be referred to as middle LEDs  37   c . When the sliding door  3  is in a semi-open state and ID authentication is established, as shown in  FIG. 10 , the control circuit  43  drives the LEDs  37  to turn on or blink in sequence in the rearward direction Rr toward the two middle LEDs  37   c  and drives the LEDs  37  to turn on or blink in sequence in the frontward direction Fr toward the two middle LEDs  37   c . This causes the LEDs  37  to turn on or blink in sequence in the rearward direction Rr toward the two middle LEDs  37   c  in a flowing manner and causes the LEDs  37  to turn on or blink in sequence in the frontward direction Fr toward the two middle LEDs  37   c  in a flowing manner. That is, the control circuit  43  sequentially drives the LEDs  37  located immediately below the first electrode  34  and the LEDs  37  located immediately below the second electrode  35  and sequentially drives the LEDs  37  located immediately below the third electrode  36  and the LEDs  37  located immediately below the second electrode  35 . In  FIG. 10 , the blank arrows indicate a mode of the LEDs  37  that turn on or blink in sequence in the rearward direction Rr toward the two middle LEDs  37   c  on the middle in the front-rear direction and turn on or blink in sequence in the frontward direction Fr toward the two middle LEDs  37   c . This is for the user to simultaneously remember that the opening operation for the sliding door  3  is rear swiping and the closing operation for the sliding door  3  is front swiping in the semi-open state of the sliding door  3 . Also, this is for the user to understand the position of the first electrode  34  or the third electrode  36 , toward which the user should initially move a part of the body. Further, this is for the user to understand that the motion of the opening-closing operation for the sliding door  3  is under reception. 
     The control circuit  43  stops detecting all the capacitance of the first to third electrodes  34  to  36  in a detection prohibiting mode. The detection prohibiting mode is employed in, for example, a situation where the reduction of the power consumption is prioritized over the detection of the opening-closing operation of the sliding door  3  by the user when ID authentication has not been established for a predetermined time. The detection prohibiting mode is also employed in a situation where an erroneous detection scene in which a person never gets on or off such as window wiping or leaning is detected. When stopping detecting all the capacitance of the first to third electrodes  34  to  36 , the control circuit  43  drives the LEDs  37  located immediately below the first to third electrodes  34  to  36  such that all the LEDs  37  turn off. This is for the user who has moved a part of the body to the first to third electrodes  34  to  36  for performing the opening-closing operation the sliding door  3  to understand that the reception of the operation is under prohibition. 
     The mode of driving the LEDs  37  in the present embodiment will now be summarized. This process is activated when, for example, the above-described detection prohibiting mode ends. 
     As shown in  FIG. 11 , when the process proceeds to this routine, the control circuit  43  determines whether ID authentication is established in step S 1 . The control circuit  43  waits for the ID authentication to be established. When the ID authentication is established, the control circuit  43  determines the state of the sliding door  3  in step S 2 . When determining that the sliding door  3  is in the fully-closed state in step S 2 , the control circuit  43  drives the LEDs  37  located immediately below the first electrode  34  such that the LEDs  37  turn on or blink in step S 3  and determines whether a part of the body has been detected by the first electrode  34  in step S 4 . When determining that a part of the body has not been detected by the first electrode  34  in step S 4 , the control circuit  43  returns to step S 3  to repeat the same process. When determining that a part of the body has been detected by the first electrode  34  in step S 4 , the control circuit  43  drives the LEDs  37  to turn on or blink in sequence in correspondence with the operation direction of rear swiping in step S 5 . Then, the control circuit  43  determines whether rear swiping has been detected in step S 6 . When determining that rear swiping has not been detected in step S 6 , the control circuit  43  returns to step S 5  to repeat the same process. When determining that rear swiping has been detected in step S 6 , the control circuit  43  drives all the LEDs  37  to turn on or blink in step S 13  and ends the process. 
     When determining that the sliding door  3  is in the fully-open state in step S 2 , the control circuit  43  drives the LEDs  37  located immediately below the third electrode  36  such that the LEDs  37  turn on or blink in step S 7  and determines whether a part of the body has been detected by the third electrode  36  in step S 8 . When determining that a part of the body has not been detected by the third electrode  36  in step S 8 , the control circuit  43  returns to step S 7  to repeat the same process. When determining that a part of the body has been detected by the third electrode  36  in step S 8 , the control circuit  43  drives the LEDs  37  to turn on or blink in sequence in correspondence with the operation direction of front swiping in step S 9 . Then, the control circuit  43  determines whether front swiping has been detected in step S 10 . When determining that front swiping has not been detected in step S 10 , the control circuit  43  returns to step S 9  to repeat the same process. When determining that front swiping has been detected in step S 10 , the control circuit  43  drives all the LEDs  37  to turn on or blink in step S 13  and ends the process. 
     When determining that the sliding door  3  is in the semi-open state in step S 2 , the control circuit  43  drives the LEDs  37  to turn on or blink in sequence in the rearward direction Rr toward the two middle LEDs  37   c  and drives the LEDs  37  to turn on or blink in sequence in the frontward direction Fr toward the two middle LEDs  37   c  in step S 11 . Then, the control circuit  43  determines whether rear swiping or front swiping has been detected in step S 12 . When determining that neither rear swiping nor front swiping has been detected in step S 12 , the control circuit  43  returns to step S 11  to repeat the same process. When determining that either rear swiping or front swiping has been detected in step S 12 , the control circuit  43  drives all the LEDs  37  to turn on or blink in step S 13  and ends the process. 
     When detecting rear swiping or front swiping, the control circuit  43  outputs to the door ECU  10  the operation signal S indicating the detection. As described above, the door ECU  10  uses the operation signal S to drive, for example, the door driving unit  11 . 
     The operation and advantages of the present embodiment will now be described. 
     (1) In the present embodiment, the operation direction indicator  43   a  drives the LEDs  37  to turn on or blink in sequence in the rearward direction Rr. Thus, when visually recognizing that the LEDs  37  are on or blinking in this manner, the user can easily remember that the opening operation for the sliding door  3  is the motion of moving a part of the body toward the first to third electrodes  34  to  36  and moving the part of the body in the rearward direction Rr. Further, the operation direction indicator  43   a  drives the LEDs  37  to turn on or blink in sequence in the frontward direction Fr. Thus, when visually recognizing that the LEDs  37  are on or blinking in this manner, the user can easily remember that the closing operation for the sliding door  3  is the motion of moving a part of the body toward the first to third electrodes  34  to  36  and moving the part of the body in the frontward direction Fr. Accordingly, how to perform the opening-closing operation for the sliding door  3  is simplified. 
     Consequently, the user is less likely to incorrectly perform the opening-closing operation for the sliding door  3 . 
     (2) In the present embodiment, when the sliding door  3  is in the semi-open state, the operation direction indicator  43   a  drives the LEDs  37  on the middle in the front-rear direction such that the LEDs  37  turn on or blink in sequence in the rearward direction Rr toward the middle LEDs  37   c  and drives the LEDs  37  on the middle in the front-rear direction such that the LEDs  37  turn on or blink in sequence in the frontward direction Fr toward the middle LEDs  37   c . By visually recognizing that the LEDs  37  are on or blinking in this manner, the user can easily remember that the opening operation and closing operation for the sliding door  3  are the motions of moving a part of the body toward the first to third electrodes  34  to  36  and moving the part of the body in the rearward direction Rr and in the frontward direction Fr, respectively. Thus, when the sliding door  3  is in the semi-open state, how to perform the opening-closing operation for the sliding door  3  is simplified. 
     (3) In the present embodiment, when ID authentication is established, the operation direction indicator  43   a  drives the LEDs  37  to turn on or blink in correspondence with the position of one of the first to third electrodes  34  to  36 , toward which the user should initially move a part of the body. By visually recognizing this, the user easily recognizes the positions of one of the first to third electrodes  34  to  36 . Thus, by quickly moving a part of the body toward the position of one of the first to third electrodes  34  to  36 , the user can smoothly advance to the opening-closing operation for the sliding door  3  that is performed subsequently. 
     (4) In the present embodiment, when the opening-closing operation for the sliding door  3  (i.e., rear swiping or front swiping) is detected, the operation direction indicator  43   a  drives all the LEDs  37  to turn on or blink. This allows the user to understand that the opening-closing operation for the sliding door  3  has been detected. Thus, there is no need for the user to pointlessly repeat the opening-closing operation while uncertain about whether the opening-closing operation for the sliding door  3  has been detected. 
     (5) In the present embodiment, in the detection prohibiting mode, the control circuit  43  drives the LEDs  37  located immediately below the first to third electrodes  34  to  36  such that all the LEDs  37  turn off. This allows the user to easily understand the reception of the opening-closing operation for the sliding door  3  is under prohibition. 
     The present embodiment may be modified as follows. The present embodiment and the following modifications can be combined as long as the combined modifications remain technically consistent with each other. 
     As shown in  FIG. 12 , the present disclosure may be applied to a vehicle  50  incorporating a back door  52 . The back door  52  opens and closes an opening  51   a  at the rear part of a body  51 . The back door  52  is coupled to the rear part of the vehicle  50  by a door hinge (not shown). The back door  52  moves in the vertical direction while pivoting around the door hinge. The back door  52  is coupled to the rear part of the body  51  by the door hinge, which is arranged on the upper part of the opening  51   a , such that the back door  52  can be opened and closed. The back door  52  opens when pushed upward with respect to the door hinge. The back door  52  moves in the upward direction to change from the fully-closed state to the fully-open state and moves in the downward direction to change from the fully-open state to the fully-closed state. 
     The middle portion of the outer surface of the back door  52 , that is, the middle portion located above a garnish  54 , is provided with an emblem  55  of, for example, a company name. As also shown in  FIG. 13 , the back part of the emblem  55  is provided with an upper electrode  56  and a lower electrode  57 . Each of the upper electrode  56  and the lower electrode  57  is the electrode of a capacitance sensor. The upper electrode  56  and the lower electrode  57  are laid out so as to be spaced apart from each other in the up-down direction, which corresponds to the axis in the opening-closing direction of the door. That is, the upper electrode  56  and the lower electrode  57  correspond to sensors laid out in the vehicle  50  along the axis in the opening-closing direction of the door of the vehicle  50 . The upper electrode  56  is located in the upper part of the emblem  55  and has a substantially crescent shape corresponding to the upper edge of the emblem  55 . The lower electrode  57  is located in the lower part of the emblem  55  and has a substantially crescent shape corresponding to the lower edge of the emblem  55 . Needless to say, the upper electrode  56  and the lower electrode  57  are spaced apart from each other in the up-down direction. The upper electrode  56  and the lower electrode  57  change in capacitance when a part of the body of the user moves toward the emblem  55 . 
     In a normal operation of this modification, the motion of the user moving a part of the body toward the emblem  55  represents the operation of opening and closing the back door  52 . That is, for example, the motion of the user moving a part of the body from the lower electrode  57  toward the upper electrode  56  in the vertical direction (hereinafter referred to as upper swiping) represents the operation of opening the back door  52 , and the motion of the user moving a part of the body from the upper electrode  56  toward the lower electrode  57  in the vertical direction (hereinafter referred to as lower swiping) represents the operation of closing the back door  52 . Upper swiping may represent the operation of opening the sliding door  3  and unlocking the door lock  6  corresponding to the opening operation. Lower swiping may represent the operation of opening the back door  52  and locking the door lock  6  corresponding to the closing operation. 
     Further, the back part of the emblem  55  is provided with LEDs  58  on the opposite sides of the upper electrode  56  and the lower electrode  57  in the width direction. The LEDs  58  are laid out so as to be spaced apart from one another in the up-down direction, which corresponds to the axis in the opening-closing direction of the door. The LEDs  58  correspond to light-emitting members laid out in the vehicle  50  along the axis in the opening-closing direction. The LEDs  58  are driven to turn on or blink in sequence in an upward direction Up when, for example, the reception of the opening operation for the back door  52  is completed. The upward direction Up corresponds to the first direction, which is the axis corresponding to the opening direction of the door. This causes the LEDs  58  to turn on or blink in sequence in the upward direction Up in a flowing manner. In  FIG. 13 , a mode in which the LEDs  58  turn on or blink in sequence in the upward direction Up is indicated by a blank arrow. The LEDs  58  are driven to turn on or blink in sequence in a downward direction Dw when, for example, the reception of the closing operation for the back door  52  is completed. The downward direction Dw corresponds to the second direction, which is the axis corresponding to the closing direction of the door. This causes the LEDs  58  to turn on or blink in sequence in the downward direction Dw in a flowing manner. In  FIG. 13 , a mode in which the LEDs  58  turn on or blink in sequence in the downward direction Dw is indicated by a blank arrow. When the LEDs  58  are driven to indicate upper swiping or lower swiping, the brightness of the LEDs  58  may be varied. 
     Even if such a change is made, the same advantages as those of the above-described embodiment can be gained. 
     The back door  52 , for example, opens and closes when the door driving unit  11  and the door lock driving unit  12  are driven by the door ECU  10  in correspondence with the sliding door  3 . 
     As shown in  FIG. 14 , the side part of the body  2  may be provided with a side skirt (rocker cover)  9  extending in the front-rear direction along the lower edge of the opening  2   a . In this case, the side skirt  9  may include infrared sensors  61 ,  62 , and  63 , which correspond to the sensors, such that they are laid out so as to be spaced apart from one another in the front-rear direction. The front-rear direction corresponds to the axis in the opening-closing direction of the door. The infrared sensors  61  to  63 , which correspond to the sensors, may be laid out so as to be spaced apart from one another in the front-rear direction in a side mudguard (not shown) extending in the front-rear direction along the lower edge of the sliding door  3 . The front-rear direction corresponds to the axis in the opening-closing direction of the door. The infrared sensors  61  to  63  are laid out in sequence in the front-rear direction from the front toward the rear. Each of the infrared sensors  61  to  63  outputs a detection signal that changes when a part of the body of the user such as a foot F moves toward the surface of the side skirt  9 . 
     In a normal operation of this modification, the motion of the user moving a part of the body of the user toward the side skirt  9  represents the operation for opening and closing the sliding door  3 . That is, for example, the motion of the user moving a part of the body in the rearward direction (i.e., rear swiping) represents the operation for opening the sliding door  3  and unlocking the door lock  6  corresponding to the opening operation. The motion of the user moving a part of the body in the frontward direction (i.e., front swiping) represents the operation for closing the sliding door  3  and locking the door lock  6  corresponding to the closing operation. Rear swiping may represent only the operation for opening the sliding door  3 . Likewise, front swiping may represent only the operation for closing the sliding door  3 . 
     There may be any number of infrared sensors arranged in the side skirt  9  as long as the number of the infrared sensors is multiple. Further, the infrared sensors may be replaced with, for example, the electrodes of capacitance sensors, optical sensors (such as pyroelectric sensors), ultrasonic sensors, or heat sensors. 
     The side skirt  9  includes LEDs  66  on the lower side of the infrared sensors  61  to  63 . The LEDs  66  are laid out so as to be spaced apart from one another in the front-rear direction, which corresponds to the axis in the opening-closing direction of the door. The LEDs  66  correspond to the light-emitting members laid out in the vehicle  1  along the axis in the opening-closing direction. The LEDs  66  are driven to turn on or blink in sequence in the rearward direction Rr when, for example, the reception of the opening operation for the sliding door  3  is completed. The rearward direction Rr corresponds to the first direction, which is the axis corresponding to the opening direction of the door. The LEDs  66  are driven to turn on or blink in sequence in the frontward direction Fr when, for example, the reception of the closing operation for the sliding door  3  is completed. The frontward direction Fr corresponds to the second direction, which is the axis corresponding to the closing direction of the door. 
     Even if such a change is made, the same advantages as those of the above-described embodiment can be gained. 
     Referring to  FIG. 15 , a sensor unit  70  including a case  71  may be employed. In the case  71 , LEDs  73 , which correspond to the light-emitting members, are arranged above an electrode  72  of a capacitance sensor, which corresponds to the sensor. Further, the case  71  may accommodate a light guide  74  and include a through-hole  71   a . The light guide  74  is located closer to the window glass  5  than the LEDs  73 . The through-hole  71   a  is opposed to the light guide  74 . 
     Referring to  FIG. 16 , a sensor unit  80  including a case  81  may be employed. In the case  81 , LEDs  83 , which correspond to the light-emitting members, are arranged below an electrode  82  of a capacitance sensor, which corresponds to the sensor. Further, light guides  84  are arranged above and below the LEDs  83 . 
     In the above-described embodiment, the position sensor  22  may be a position sensor that directly detects the opening-closing position of the sliding door  3 . Alternatively, the position sensor  22  may be a rotation sensor that detects a rotation position of the door driving unit  11  (for example, the rotation shaft of an electric motor or the output shaft of a reduction drive), which opens and closes the sliding door  3 . The rotation sensor may include, for example, a potentiometer, a rotary encoder, or a Hall sensor. 
     In the above-described embodiment, rear swiping may only represent only the operation for opening the sliding door  3 . Likewise, front swiping may represent only the operation for closing the sliding door  3 . 
     In the above-described embodiment, the LEDs  37 ,  73 , and  83  may be arranged in the side skirt  9  or the side mudguard such that they are spaced apart from one another in the front-rear direction, which corresponds to the axis in the opening-closing direction of the door. 
     In the above-described embodiment, there may be any number of electrodes of the sensor units  30 ,  70 , and  80  as long as the number of the electrodes is multiple. 
     In the above-described embodiment, the sensor units  30 ,  70 , and  80  may be incorporated in a belt molding  8 , which is shown in  FIG. 1 . 
     In the above-described embodiment, when ID authentication is established in the fully-closed state of the sliding door  3 , the LEDs  37 ,  66 ,  73 , and  83  may be driven to turn on or blink in sequence in the rearward direction Rr. Likewise, when ID authentication is established in the fully-open state of the sliding door  3 , the LEDs  37 ,  66 ,  73 , and  83  may be driven to turn on or blink in sequence in the frontward direction Fr. 
     In the above-described embodiment, when the LEDs  37 ,  66 ,  73 , and  83  are driven to indicate rear swiping or front swiping, the brightness of the LEDs  37 ,  66 ,  73 , and  83  may be varied. 
     In the above-described embodiment, in each operation mode, the LEDs  37 ,  58 ,  66 ,  73 , and  83  may turn on or blink and turn off in reverse. That is, in each operation mode, the LEDs  37 ,  58 ,  66 ,  73 , and  83  that have been on or have blinked may turn off and the LEDs  37 ,  58 ,  66 ,  73 , and  83  that have been off may turn on or blink. 
     In the above-described embodiment, as long as the sensors are laid out in the vehicle at positions that do not disturb operation performed by the user, the arrangement of the sensors may be changed. For example, when the operation target is the back door  52 , the sensors may be located on the surface of the garnish  54 . When the operation target is the sliding door  3 , the sensors may be located on the surface of a pillar or an outside door handle. In short, the sensors simply need to be laid out in the vehicles  1  and  50  along the axis in the opening-closing direction of the door. 
     In the above-described embodiment, as long as a detection signal that changes when a part of the body of the user moves toward the sensors can be output, the sensors may be infrared sensors, optical sensors (such as pyroelectric sensors), ultrasonic sensors, or heat sensors. 
     In the above-described embodiment, the door may be, for example, a swing door, a hood, or a trunk lid. 
     The control circuit  43  (for example, operation direction indicator  43   a ) is not limited to a device that includes a CPU and a ROM and executes software processing. For example, a dedicated hardware circuit (such as an ASIC) may be provided that executes at least part of the software processes executed in the above-described embodiment. That is, control circuit  43  (for example, operation direction indicator  43   a ) may be modified as long as it has any one of the following configurations (a) to (c). (a) A configuration including a processor that executes all of the above-described processes according to programs and a program storage device such as a ROM that stores the programs. (b) A configuration including a processor and a program storage device that execute part of the above-described processes according to the programs and a dedicated hardware circuit that executes the remaining processes. (c) A configuration including a dedicated hardware circuit that executes all of the above-described processes. A plurality of software execution devices each including a processor and a program storage device and a plurality of dedicated hardware circuits may be provided. That is, the above-described processes may be executed in any manner as long as the processes are executed by processing circuitry that includes at least one of a set of one or more software execution devices and a set of one or more dedicated hardware circuits. The program storage devices, or computer readable media, include any type of media that are accessible by general-purpose computers and dedicated computers. 
     Various changes in form and details may be made to the examples above without departing from the spirit and scope of the claims and their equivalents. The examples are for the sake of description only, and not for purposes of limitation. Descriptions of features in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if sequences are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined differently, and/or replaced or supplemented by other components or their equivalents. The scope of the disclosure is not defined by the detailed description, but by the claims and their equivalents. All variations within the scope of the claims and their equivalents are included in the disclosure.