Abstract:
A vehicle is provided with an opening and closing device for opening and closing the vehicle door. A hook mechanism holds the door in an open condition, an electric releasing actuator is operatively connected to the hook mechanism to unhook the hook mechanism for permitting the door to be moved in the closing direction, an electric driving device is adapted to move the door in the closing direction, and an operation device generates a signal for directing that the door be moved in the closing direction. In addition, a control device controls the operation of the electric releasing actuator based upon the signal from the operation device, and controls the electric driving device to initiate driving operation of the electric driving device after initiation of the operation of the electric releasing actuator.

Description:
This application is based on and claims priority under 35 U.S.C. §119 with respect to Japanese Application No. 2001-058158 filed on Mar. 2, 2001, the entire content of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     This invention generally relates to vehicle doors. More particularly, the present invention pertains to an opening and closing device for a vehicle door. More particularly, this invention pertains to a vehicle door opening and closing device provided with a hook mechanism for holding a vehicle door under a door opened condition relative to a vehicle body and a moving mechanism for moving the vehicle door relative to the vehicle body. 
     BACKGROUND OF THE INVENTION 
     There are a variety of known opening and closing devices for opening and closing a vehicle door. Japanese Patent Laid-Open Publication 2000-160935 discloses one such vehicle door opening and closing device. The device described in this document includes a slide door movably supported by a vehicle body so as to open and close an opening defined in the vehicle body for allowing an individual to enter and exit the interior of the vehicle. The vehicle door opening and closing device is provided with an open position holding mechanism, a moving mechanism, and an electric driving mechanism. The open position holding mechanism holds the slide door under a door opened condition relative to the vehicle body, while the moving mechanism slidably moves the slide door relative to the vehicle body. The electric driving mechanism is operatively connected to the moving mechanism for operating the moving mechanism to slidably move the slide door for closing the opening. 
     The open position holding mechanism holds the slide door in the door opened condition by the biasing force of a biasing mechanism such as a spring. The open position holding mechanism is operated when the moving force of the slide door moving in the closing direction under operation of the moving mechanism operated by the electric driving mechanism exceeds the biasing force of the open position holding mechanism. 
     The vehicle door opening and closing device described above is susceptible of certain improvements. For example, when the electric driving mechanism is not operated while the vehicle is parked in a down-hill, the slide door may slidably move by itself in the closing direction. Therefore, the open position holding mechanism may be operated and the slide door may not be held at the door opened position. 
     Accordingly, a need exists for a vehicle door opening and closing device that is able to reliably hold the slide door in the door opened position. 
     SUMMARY OF THE INVENTION 
     A vehicle provided with an opening and closing device for a vehicle door includes a vehicle body having an opening which permits access into and out of the vehicle, a vehicle door movably supported by the vehicle body for opening and closing the opening, a hook mechanism which holds the vehicle door relative to the vehicle body under a door opened condition, a moving mechanism which moves the vehicle door relative to the vehicle body, an electric releasing actuator operatively connected to the hook mechanism to operate the hook mechanism and effect unhooking of the hook mechanism to permit the vehicle door to be moved in a closing direction to close the opening, an electric driving device operatively connected to the moving mechanism to operate the moving mechanism and move the vehicle door in the closing direction relative to the vehicle body to close the opening, and an operation means for generating a signal indicating that the vehicle door is to be moved in the closing direction to close the opening. A control means controls the operation of the electric releasing actuator based on the signal from the operation means and controls the operation of the electric driving device to initiate driving of the moving mechanism after initiating operation of the electric releasing actuator. 
     The operation of the hook mechanism is performed by driving the electric releasing actuator. Therefore, the hook mechanism is not operated even when the vehicle door is applied with a force which moves the door in a closing direction for closing the opening. That is, the operation of the hook mechanism is not associated with the moving force applied to the vehicle door upon a closing operation of the vehicle door. Therefore, the vehicle door can be reliably held at the door opened position relative to the vehicle body. 
     It is preferable that the control means includes a timing means for commencing counting from the initiation of the operation of the electric release motor. The control means terminates the operation of the electric release motor and controls starting of the operation the electric driving device based upon the lapsed time counted by the timing means from the initiation of the operation of the electric release motor. 
     In addition, a detecting means detects the movement of the vehicle door relative to the vehicle body, with the control means terminating operation of the electric releasing actuator based upon the movement of the vehicle door detected by the detecting means or the lapsed time counted by the timing means. The timing means and the detecting means allow termination of the operation of the electric release motor and the starting of operation of the electric driving mechanism. Therefore, the hook mechanism is not required to be additionally provided with a detecting means for detecting the operation of the hook mechanism. This leads to a decrease in the number of components and a reduction in the manufacturing cost. 
     According to another aspect, a method for closing an opening defined in a vehicle body of a vehicle through movement of a vehicle door relative to the vehicle body involves operating an electric release motor operatively connected to a hook mechanism holding the vehicle door at an open condition to unhook the hook mechanism, with the driving of the electric release motor being initiated based upon operation of a switch, counting lapsed time from initiation of the operation of the electric release motor, judging whether the lapsed time from the initiation of the operation of the electric release motor is at least equal to a first predetermined time, and initiating driving of an electric driving mechanism for moving the vehicle door in a closing direction relative to the vehicle body based on whether the lapsed time from the initiation of operation of the electric release motor is at least equal to the first predetermined time. 
     In accordance with another aspect, a method for closing an opening defined in a vehicle body of a vehicle through movement of a vehicle door relative to the vehicle body includes directing a door closing operation of the vehicle door that is in an open condition, releasing a hook mechanism holding the door at the open condition by operation of a first motor operatively connected to the hook mechanism, counting lapsed time from initiation of operation of the first motor, and operating a second motor to move the vehicle door relative to the vehicle body in a closing direction based upon the lapsed time from the initiation of operation of the first motor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawing figures in which like reference numerals designate like elements. 
     FIG. 1 is a side view of a vehicle door schematically illustrating the vehicle door provided with an opening and closing device according to the present invention. 
     FIG. 2 is a schematic block diagram of the vehicle door opening and closing device. 
     FIG. 3 is a flow chart illustrating the main routine associated with the control operation of the vehicle door opening and closing device. 
     FIG. 4 is a flow chart illustrating a part of the subroutine associated with the door closing operation mode carried out in the main routine shown in FIG.  3 . 
     FIG. 5 is a flow chart illustrating another part of the subroutine associated with the door closing operation mode carried out in the main routine shown in FIG.  3 . 
     FIG. 6 is a flow chart illustrating a part of the subroutine associated with the door opening operation mode carried out in the main routine shown in FIG.  3 . 
     FIG. 7 is a flow chart illustrating another part of the subroutine associated with the door opening operation mode carried out in the main routine shown in FIG.  3 . 
     FIG. 8 is a timing chart illustrating the operation of the vehicle door opening and closing device for the door closing operation of the vehicle door. 
     FIG. 9 is a timing chart illustrating the operation of the vehicle door opening and closing device for the door opening operation of the vehicle door. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a vehicle body  2  of a vehicle is provided with an opening  21  that allows access into the interior of the vehicle to allow individuals to enter and exit the vehicle interior. A vehicle door  1  is movably supported by the vehicle body  2  and is slidably movable relative to the vehicle body  2  in the vehicle longitudinal direction. The vehicle door  1  can be held at a door closed condition in which the opening  21  in the vehicle body is closed and at a door opened condition in which the opening  21  in the vehicle body is opened and accessible. 
     The vehicle door  1  is provided with a pair of latch mechanisms  3 ,  4  and a hook mechanism  5 . The latch mechanisms  3 ,  4  are respectively arranged at the front and rear portions of the vehicle door  1  for holding the vehicle door  1  under the door closed condition relative to the vehicle body  2 . The hook mechanism  5  is employed for holding the vehicle door  1  under the door opened condition relative to the vehicle body  2 . The vehicle door  1  is further provided with an inside handle  61  at the inner side of the vehicle door  1 , an outside handle  62  at the outer side of the vehicle door  1 , and a remote control mechanism  6 . The inside handle  61 , the outside handle  62 , the latch mechanisms  3 ,  4  and the hook mechanism  5  are physically connected via the remote control mechanism  6  by way of a connecting means including a rod and a cable. Therefore, the remote control mechanism  6  operates the latch mechanisms  3 ,  4  and the hook mechanism  5  through an individual&#39;s manual operation of the inside handle  61  or the outside handle  62 . 
     The remote control mechanism  6  with a known construction formed of plural levers is provided with a lock actuator  63  and a child protecting mechanism  64 . The lock actuator  63  establishes a door locked condition of the vehicle door  1  in which the connection between the inside handle  61  and the latch mechanisms  3 ,  4 , and the connection between the outside handle  62  and the latch mechanisms  3 ,  4  are interrupted. The child protecting mechanism  64  is employed for locking the vehicle door  1  to protect a child from opening the vehicle door  1  (a child locking condition). In this case, the connection between the inside handle  61  and the latch mechanisms  3 ,  4  is interrupted. The lock actuator  63  is provided with a lock switch  66  (referred to as a lock SW in the flow chart illustrated in FIG. 6) for detecting the door locked condition of the vehicle door  1  and for transmitting an ON signal to a controller  7  while the vehicle door  1  is under the door locked condition. The child protecting mechanism  64  is provided with a child protecting switch  67  (referred to as a child-protect SW in the flow chart illustrated in FIG. 6) for detecting the child locking condition of the vehicle door  1  and for transmitting an ON signal to the controller  7  while the vehicle door  1  is under the child locking condition. 
     The latch mechanisms  3 ,  4  are formed of a known construction including a latch and a pawl, respectively. The latch is freely rotatably engageable with and disengageable from a striker fixed to the vehicle body  2 . The pawl is engageable with and disengageable from the latch. The latch mechanisms  3 ,  4  establish a full-latched condition in which the vehicle door  1  is held under a door full-closed condition, a half-latched condition in which the vehicle door  1  is held under a door half-closed condition, and an unlatched condition in which the vehicle door  1  is slidably movable in a direction for opening the opening  21 . 
     The latch mechanism  4  is provided with a full-latch switch  41  (referred to as a full-latch SW in the flow chart illustrated in FIG.  5  and in the timing charts illustrated in FIGS. 8 and 9) for detecting the full-latched condition of the latch mechanism  4 , a half-latch switch  42  (referred to as a half-latch SW in the flow charts illustrated in FIGS. 5 and 7 and in the timing charts illustrated in FIGS. 8 and 9) for detecting the half-latched condition of the latch mechanism  4 , and a pawl switch  43  (referred to as a pawl SW in the flow charts illustrated in FIGS. 5 and 6 and in the timing charts illustrated in FIGS. 8 and 9) for detecting movement of the pawl establishing the full-latched condition, the half-latched condition, and the unlatched condition. 
     As illustrated in FIG. 8, the full-latch switch  41  detects from the condition of the latch mechanism  4  that the vehicle door  1  has not reached the door full-closed condition while the opening  21  is opened and outputs an ON signal to the controller  7 . With the latch mechanism in the half-latched condition, the full-latch switch  41  outputs an OFF signal to the controller  7  through switching operation of the switch immediately before the latch mechanism  4  reaches or becomes the full-latched condition. The half-latch switch  42  detects from a condition of the latch mechanism  4  that the vehicle door  1  has not reached the door half-closed condition while the opening  21  is opened and outputs an ON signal to the controller  7 . With the latch mechanism in the unlatched condition, the half-latch switch  42  outputs an OFF signal to the controller  7  through a switching operation of the switch immediately before the latch mechanism  4  reaches or becomes the half-latched condition. The pawl switch  43  outputs an OFF signal when the pawl is engaged with the latch and outputs an ON signal when the pawl is disengaged from the latch. That is, the pawl switch  43  selectively outputs the ON and OFF signals in response to the movement of the pawl establishing the full-latched condition, the half-latched condition, and the unlatched condition. 
     The latch mechanism  4  is further provided with an electric closing mechanism  44  for shifting the latch mechanism  4  from the half-latched condition to the full-latched condition. The electric closing mechanism  44  is formed of a known construction including an electric motor  45  (referred to as a closing motor in the flow chart illustrated in FIG. 5) as a driving power source. The latch of the latch mechanism  4  is rotated by a latch lever (not shown) in response to rotation of the electric motor  45 . 
     The hook mechanism  5  is formed of a construction including a hook that is freely rotatably engaged with and disengaged from an engagement pin provided at the vehicle body  2 . The hook mechanism  5  establishes a hooked condition in which the vehicle door  1  is held under the door opened condition, and an unhooked condition in which the vehicle door  1  is slidably movable in the closing direction for closing the opening  21 . 
     The vehicle door  1  is provided with an electric releasing actuator  8  including an electric motor  81  (referred to as a release motor in the flow charts illustrated in FIGS. 4,  6  and  7 ) as a driving power source. The electric releasing actuator  8  is physically connected to the pair of latch mechanisms  3 ,  4  and the hook mechanism  5  via the remote control mechanism  6  by means of a connecting mechanism that includes a rod and a cable. Therefore, the latch mechanisms  3 ,  4  and the hook mechanism  5  are operated by driving or operating the electric motor  81 . 
     The vehicle door  1  is further provided with an electric sliding mechanism or moving mechanism  9  provided with an electric motor  91  (referred to as a sliding motor in the flow charts illustrated in FIGS. 5,  7 ) as a driving power source. The electric sliding mechanism  9  is formed of a known construction including a cable connected to the vehicle body  2  and a drum for winding the cable. The vehicle door  1  can be slidably moved relative to the vehicle body  2  in the opening direction for opening the opening  21  when the drum is rotated by the motor or electric driving device  91  for rolling up the cable. On the other hand, the vehicle door  1  can be slidably moved relative to the vehicle body  2  in the closing direction for closing the opening  21  when the drum is rotated by the motor  91  for sending out the cable. The electric sliding mechanism or moving mechanism  9  is further provided with a position sensor  92  (e.g., a Hall IC) for detecting the rotational number or number of rotations of the electric motor  91 . 
     The vehicle door  1  is further provided with the controller  7  for controlling the operation of the electric releasing actuator  8 , the electric sliding mechanism  9 , and the electric closing mechanism  44  by way of a central processing unit CPU  71 . As illustrated in FIG. 2, the CPU  71  included in the controller  7  is electrically connected to the child protecting switch  67 , the lock switch  66 , the full-latch switch  41 , the half-latch switch  42 , and the pawl switch  43  via an input interface  72  through a connecting means including a wire harness so as to receive signals from the switches  41   42 ,  43 ,  66 ,  67 . The CPU  71  is also electrically connected to the electric motors  45 ,  81 ,  91  via a driving circuit  73  through a connecting means including a wire harness. The CPU  71  is further electrically connected to a driver seat switch  22  (referred to as the driver seat SW in the flow charts illustrated in FIGS. 4 and 6) and a pillar portion switch  23  (referred to as a pillar portion SW in the flow charts illustrated in FIGS. 4 and 6) via the input interface  72  through a connecting means including a wire harness. 
     The CPU  71  also includes a timer  74  for counting two lapsed times T 1 , T 2 . The CPU  71  is electrically connected to the position sensor  92  by a connecting means including a wire harness to calculate a position of the vehicle door  1  relative to the vehicle body  2  based upon a signal from the position sensor  92 . 
     Referring to the flow charts illustrated in FIGS. 3-7 and the timing charts illustrated in FIGS. 8 and 9, the operation of the controller  7  is as follows. Considering initially the flow chart illustrated in FIG.  3  and the timing charts illustrated in FIGS. 8 and 9, an initial process is performed at step S 1  when the vehicle door  1  is under the door fully-opened condition relative to the vehicle body  2 . More specifically, the CPU  71  observes the condition of the full-latch switch  41 , the half-latch switch  42  and the pawl switch  43 , and judges that the full-latch switch  41  and the half-latch switch  42  are ON and the pawl switch  43  is OFF. An operational process for the closing operation of the vehicle door  1  is performed at step S 2  based upon the condition of the driver seat switch  22  or the pillar portion switch  23 . An initial process is performed at step S 3  under a door full-closed condition of the vehicle door  1  relative to the vehicle body  2 . More specifically, the CPU  71  observes each condition of the full-latch switch  41 , the half-latch switch  42 , and the pawl switch  43  and judges that the each switch  41 ,  42 , and  43  is OFF. An operational process for effecting the opening operation of the vehicle door  1  is then performed at step S 4  based upon the condition of the driver seat switch  22  or the pillar portion switch  23 . 
     The door closing operation mode of the vehicle door  1  carried out in step S 2  of FIG. 2 is described below with reference to the flow charts illustrated in FIGS. 4 and 5 and the timing chart illustrated in FIG.  8 . Either the driver seat switch  22  or the pillar portion switch  23  is first operated manually by the occupant. At step S 5 , the CPU  71  detects whether or not either the switch  22  or the switch  23  has sent an ON signal. If the determination in step S 5  is YES, the program proceeds to step S 6  for driving the electric releasing actuator  8 , that is to drive the electric motor  81  so as to operate the hook mechanism  5 . The hook mechanism  5  hence establishes the unhooked condition with the engagement pin being disengaged from the hook. Therefore, the vehicle door  1  is released from the door opened condition. Further, at step S 6 , the timer  74  commences counting almost simultaneously with the starting of the driving operation of the electric motor  81 . The program then proceeds to step S 7  at which the CPU  71  judges whether or not the actual time counted by the timer  74  from the starting of the driving operation of the electric motor  81  has reached a predetermined lapsed time TI. 
     If the judgment at step S 7  is YES, the program precedes to step S 8  for driving the electric sliding mechanism  9 , that is to drive the electric motor  91  to rotate in a direction for slidably moving the vehicle door  1  in the closing direction to close the opening  21 . The predetermined time T 1  is preset to be equal to or greater than an operating time of the hook mechanism  5 , i.e., the time required for establishing the unhooked condition with the engagement pin being disengaged from the hook. Therefore, when the affirmative judgment is obtained at step S 7 , the CPU  71  judges that the vehicle door  1  has been released from the door opened condition. 
     After step S 8 , the program proceeds to step S 9  in which the CPU judges, based upon the signal from the position sensor  92 , whether or not the position of the vehicle door  1  is beyond a predetermined door full-opened range L 1  and the vehicle door  1  is positioned at a door closed side. If the judgment at step S 9  is YES, the program directly proceeds to step S 11  to terminate the driving operation of the electric motor  81  so that the hook mechanism  5  is returned to the hooked condition with the engagement pin being engaged with the hook. On the other hand, if the determination at step S 9  is NO, the program proceeds to step S 10  in which the CPU  71  judges whether or not the actual time counted by the timer  74  from the starting of the driving operation of the electric motor  81  has reached a predetermined lapsed time T 2 . If the determination in step S 10  is YES, the program proceeds to step S 11  to terminate the driving operation of the electric motor  81  so that the hook mechanism  5  is returned to the hooked condition with the engagement pin being engaged with the hook. The door full-opened range L 1  is preset within a range of the position of the vehicle door  1  to be held under the door opened condition by the hook mechanism  5  establishing the hooked condition. The predetermined time T 2  is preset to be equal to or greater than the time required to set the position of the vehicle door  1  beyond the door full-opened range LI by the electric sliding mechanism  9 . Therefore, the CPU  71  reliably prevents at steps S 9  and S 10  the vehicle door  1  from being returned to the door opened condition. 
     At step S 12 , the CPU  71  judges whether or not the half-latch witch  42  outputs an OFF signal. If the determination in step S 12  is YES, the CPU  71  judges that the larch mechanisms  3 ,  4  are under the half-latched condition in which the vehicle door  1  is under the door half-closed condition. The program then proceeds to step S 13  to begin driving operation of the electric motor  45  of the electric closing mechanism  44 , wherein the latch mechanisms  3 ,  4  are shifted from the half-latched condition to the full-latched condition. In other words, the vehicle door  1  is shifted from the door half-closed condition to the door full-closed condition. Next, at step S 14 , the CPU  71  judges whether or not the pawl switch  43  has been switched from ON to OFF during the shifting operation of the latch mechanisms  3 ,  4  from the half-latched condition to the full-latched condition. If the judgment in step S 14  is YES, the program proceeds to step S 15  to terminate the driving operation of the electric motor  91 . At step S 16 , the CPU  71  judges whether or not the full-latch switch  41  is OFF. If the determination in step S 16  is YES, the program proceeds to step S 17  for judging again whether or nor the pawl switch  43  was switched from ON to OFF. If the judgment in step S 17  is YES, the CPU  71  judges that the latch mechanisms  3 ,  4  are under the full-latched condition, i.e., the vehicle door  1  is under the door full-closed condition. The program then proceeds to step S 18  for terminating the driving operation of the electric motor  45 . 
     The opening operation of the vehicle door  1  is described below with reference to the flow charts illustrated in FIGS. 6 and 7 and the timing chart illustrated in FIG.  9 . The driver seat switch  22  or the pillar portion switch  23  is first operated manually by the occupant. At step S 19 , the CPU  71  judges whether or not the driver seat switch  22  is ON. If the judgment is YES, the program then proceeds to step S 21 . On the other hand, if the determination at step S 19  is NO, the program then proceeds to step S 20  for judging whether of not the pillar portion switch  23  is ON. If it is determined at step S 20  that the pillar portion switch  23  is ON (i.e, the determination in step S 20  is YES), the program proceeds to step S 22  for judging whether or not the child-protecting switch  67  is ON. If the judgment in step S 22  is NO, the program advances to step S 21 . 
     At step S 21 , the CPU  71  judges whether or not the lock switch  66  is ON. If judgment is NO at step S 21 , the program proceeds to step S 23  for driving the electric releasing actuator  8 , that is for driving the electric motor  81  to operate the latch mechanisms  2 ,  3 . The latch mechanisms  2 ,  3  then come under the unlatched condition with the latch being disengaged from the pawl. Therefore, the vehicle door  1  is released from the door closed condition. Further, at step S 23 , the timer  74  commences counting almost simultaneously with the starting of the driving operation of the electric motor  81 . Next, at step S 24 , the CPU  71  judges whether or not the pawl switch  43  has been switched from OFF to ON. If the judgment in step S 24  is YES, the CPU  71  judges that the latch mechanisms  3 ,  4  are under the unlatched condition with each latch being disengaged from the respective pawl. In this case, step S 24  is followed by step S 25  for driving the electric sliding mechanism  9 , that is for driving the electric motor  91  to slidably move the vehicle door  1  in the direction for opening the opening  21 . 
     On the other hand, if the determination in step S 21  is YES, the CPU  71  judges that the vehicle door  1  is under the door locked condition. In this case, the program returns to the step S 19 . That is, the electric motors  81 ,  91  are not driven and the vehicle door  1  is not operated for effecting the opening operation. In addition, at least when either the lock switch  66  is ON or the child protecting switch  67  is ON, the CPU  71  judges that the vehicle door  1  is under the door locked condition or that the vehicle door  1  is under the child locking condition. In this case, the program does not proceed to step S 23  for operating the electric releasing actuator  8 . Therefore, the electric motors  81 ,  91  are not driven and the vehicle door  1  is not operated for the opening operation. Therefore, the vehicle door  1  is not undesirably moved in the opening direction for opening the opening  21 , thereby assuring vehicle security. 
     After step S 25 , the program proceeds to step S 26  at which the CPU  71  judges whether or not the half-latch switch  42  is ON. If the judgment in step S 26  is YES, the CPU  71  judges that the latch mechanisms  3 ,  4  are under the unlatched condition. In this case, the program proceeds to step S 27  for judging whether or not the estimated position of the vehicle door  1  based upon the signal from the position sensor  92  is at a predetermined door opening position P 1 . If the determination in step S 27  is YES, the CPU  71  judges that the vehicle door  1  is positioned at a position in which the latch mechanisms  3 ,  4  are not operated for returning the vehicle door  1  to the door closed condition. In this case, step S 27  is followed by step S 28  for terminating the driving operation of the electric motor  81 . 
     At step S 29 , the CPU  71  judges whether or not the estimated position of the vehicle door  1  based upon the signal from the position sensor  92  is within the predetermined door full-opened range L 1 . If the determination in step S 29  is YES, the CPU  71  judges that the vehicle door  1  is at a position to be held under the door opened condition by the hook mechanism  8 . In this case, step S 29  is followed by step S 30  for terminating the driving of the electric motor  91 . The operation of the electric motor  91  is terminated by detecting an overload applied to the electric motor  91  due to a restriction of the vehicle door  1  at the door full-opened position by a stopping means. 
     If the judgments in steps S 24  and S 26  is NO, the program proceeds to steps S 31 , S 32  respectively. At step S 31 , the CPU  71  judges whether or not the actual time counted by the timer  74  from the starting of the driving operation of the electric motor  81  at step S 23  has reached a predetermined time T 3 . At step S 32 , the CPU  71  judges whether or not the actual time counted by the timer  74  from the starting of the driving operation of the electric motor  81  at step S 23  has reached a predetermined time T 4 . Further, the predetermined time T 3  is preset to be equal to or greater than a required time for switching the pawl switch  43  from OFF to ON. The predetermined time T 4  is preset to be equal to or greater than a required time for turning ON the half latch switch  42 . If the determination in steps S 31  and S 32  is YES by observing the actual time at each step by the CPU  71 , the CPU  71  judges that the latch mechanisms  3 ,  4  are under the unlatched condition. 
     Further, the vehicle door opening and closing device described above can be provided with an assisting operation device to operate the electric sliding mechanism  9 . The assisting operation device is employed for operating the electric sliding mechanism  9  based upon signals from the remote control mechanism  6 , signals from the respective handle switches mounted on the inside handle  61  and the outside handle  62  for detecting the operation of the handles  61 ,  62 , and signals from the full-latch switch  41 , the half-latch switch  42  and the pawl switch  43  when the vehicle door  1  is slidably moved for opening and closing the opening  21  in response to the manual operation of the inside handle  61  and the outside handle  62  by an individual. 
     The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.