Patent Publication Number: US-7210731-B2

Title: Door apparatus

Description:
This is a divisional of application Ser. No. 10/817,930 filed Apr. 6, 2004 now U.S. Pat. No. 7,052,073. The entire disclosure of the prior application, application Ser. No. 10/817,930 is considered part of the disclosure of the accompanying divisional application and is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The present invention relates to a door apparatus. 
     2) Description of the Related Art 
     Some vehicles like vans (“one-box” cars) have sliding doors on a side of their bodies, the side parallel to a direction in which the vehicles travel. Such a sliding door usually has a window hole, which can be shut/opened by a window glass capable of freely moving up/down. 
     In such a vehicle, a full open latch unit and a full closure latch unit are provided between the vehicle body and the sliding door. The full open latch unit is configured to keep the sliding door at a full-open position relative to the vehicle body and the full closure latch unit is configured to keep the sliding door at a full-closed position relative to the vehicle body. Therefore, when the sliding door is at the full-closed position, for example, the sliding door will not slide inadvertently in an opening direction to which the sliding door is opened even if the vehicle body is inclined. Likewise, when the sliding door is at the full-open position, the sliding door will not slide inadvertently in a closing direction to which the sliding door is closed even if the vehicle body is inclined. 
     If the sliding door is slid in the opening direction with the window glass forgotten to be closed while a foreign object is inserted in the window hole, the foreign object may be caught between a window frame of the window hole and a pillar of the vehicle body. Consequently, damages to both the foreign object and the vehicle body may be caused. 
     Therefore, a middle stopper mechanism, which stops the sliding door at a position before the full-open position if an openness of the window hole or a degree to which the window hole is opened is greater than a predetermined threshold, even when the sliding door is slid in the door opening direction, may be provided to avoid the above problems, as disclosed in Japanese Patent Application Laid-Open No. 2001-173296 and Japanese Patent No. 3263805. 
     The middle stopper mechanism includes a middle striker provided at the vehicle body and a stopper member called a “pole” provided at the sliding door so as to be able to swing. When the openness of the window hole is equal to or less than the threshold, the stopper member is engaged with a hook member so as to be kept at a retracted position against a force applied by a forcing unit such as a spring and to not interfere with sliding of the sliding door. 
     If the openness of the window hole is greater than the threshold, the stopper member is released from being engaged with the hook member, so that the stopper member projects toward the vehicle body by the force applied by the forcing unit. As a result, when the sliding door is slid in the opening direction, the stopper member projected abuts on the middle striker to hinder the sliding door from sliding further. Therefore, even if the foreign object is stuck out through the window hole, the foreign object will not be caught between the window frame and the vehicle body. 
     The stopper member, however, is moved so as to project whenever the openness of the window hole exceeds the threshold. For example, the stopper member is moved so as to project even if the sliding door is already in the full-open position, and the foreign object cannot be put in/out through the window hole or the foreign object can be put in/out through the window hole but will not be caught between the window frame and the vehicle body. 
     There is no problem in the stopper member moving so as to be projected when the openness of the window hole exceeds the threshold for preventing the foreign object passing through the window hole from being caught. However, when the sliding door at the full-open position is slid in the closing direction, there is a problem in that a portion of the stopper member which is not originally designed as a portion to be abutted on the middle striker is abutted on the middle striker. Consequently, unpleasant noises are generated during the operation and sliding of the sliding door in the closing direction may be interfered. In particular, when the vehicle body is inclined, the sliding door may slide abruptly in the closing direction, making the above problem more significant. 
     Furthermore, when operating the sliding door, a user of the vehicle may not always stop the sliding door at the full-open position or the full-closed position. Particularly if the vehicle is long like the vans, a distance for which the sliding door is slided from the full-closed position to the full-open position is long. Therefore, the sliding door may be slided only by a small distance and stopped there (hereinafter referred to as being in a “half-open” state) for putting in/out a small baggage, for example. 
     When the sliding door is in the half-open state, the full open latch unit and the full closure latch unit of the vehicle do not function. Therefore, if the vehicle is inclined, the sliding door may possibly start moving due to the gravity. 
     When the sliding door is closed, a weather strip provided between the sliding door and the vehicle body along the entire circumference sufficiently functions as a pad so as to prevent generation of a loud noise even if the sliding door moves and reaches at a high speed the full-closed position. 
     However, when the sliding door is operated to open, the sliding door reaches the full-open position with a member called a full-open stopper colliding with a surface of the vehicle body and without the weather strip functioning as the pad. Accordingly, even if the pad such as rubber is provided between the full-open stopper and the surface of the vehicle body, it is difficult to prevent generation of a loud noise if the sliding door moving at a large speed reaches the full-open position. In a vehicle provided with a middle stopper mechanism, it is difficult to ensure sufficient strength with the stopper member. Not only the noise but also a damage to the middle stopper mechanism may thus be caused. 
     Further, since the stopper member is often provided at a lower portion of the sliding door, mud or water droplets may adhere on the forcing unit. Accordingly, the force applied by the forcing unit is likely to decrease by the adhesion of mud, or by freezing of the water droplets adhered. As a result, the stopper member cannot be fully projected toward the vehicle body, so that when the sliding door with the window hole open is slid in the opening direction, the sliding door may reach the full-open position because the stopper member cannot abut on the middle striker. 
     Moreover, even if the sliding door is restricted from reaching the full-open position, the sliding door is still able to slide in the opening direction, and getting in/out of passengers is still allowed. Therefore, if the user forgets to close the window glass, closes the sliding door, and leaves the vehicle, things left inside the vehicle may be stolen. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to solve at least the problems in the conventional technology. 
     A sliding door apparatus according to an aspect of the present invention includes a sliding door having a window hole and configured to be slidable with respect to a vehicle body; an opening/closing member configured to open and close the window hole; a window hole openness detector configured to detect a position of the opening/closing member relative to the window hole so as to determine an openness of the window hole; a door position detector configured to detect a position of the sliding door relative to the vehicle body; and a slide restricting unit configured to be activated to project from one to another one of the vehicle body and the sliding door, so as to abut on the another one such that the sliding door is stopped from sliding in a direction toward which the sliding door is opened relatively to the vehicle body, when the openness determined by the window hole openness detector is greater than a threshold, and the position of the sliding door is detected to be between a full-closed position and a midway position. 
     A sliding door apparatus according to another aspect of the present invention includes a sliding door configured to be slidable with respect to a vehicle body; a door speed detector configured to detect a speed of the sliding door at least when the sliding door slides in a direction toward which the sliding door is opened; and a braking unit configured to brake down the sliding door when the speed detected is greater than a threshold. 
     A sliding door apparatus according to still another aspect of the present invention includes a sliding door configured to be slidable with respect to a vehicle body and having a window hole configured to be opened/closed; a restricting unit having an abutting portion configured to advance from and retract back to the sliding door to and from the vehicle body and to restrict the sliding door from fully opening when the abutting portion advances so as to abut on a predetermined portion of the vehicle body; a forcing unit configured to apply a force on the abutting portion so as to keep the abutting portion retracted from the vehicle body; and a driving unit configured to drive the abutting portion such that the abutting portion advances to the vehicle body against the force applied by the forcing unit when an openness of the window hole is greater than a threshold. 
     A vehicle door apparatus according to still another aspect of the present invention includes a door having a window hole configured to be opened/closed; and a door closure preventing unit configured to cancel closure of the door, if the door is closed with respect to the vehicle body when the window hole is open. 
     A vehicle door apparatus according to still another aspect of the present invention includes a door having a window hole configured to be opened/closed; and a door closure preventing unit configured to prevent the door from being closed if the door is moved to be closed with respect to the vehicle body when the window hole is open. 
     The other objects, features, and advantages of the present invention are specifically set forth in or will become apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side view of a four-wheeled automobile having a sliding door apparatus according to a first embodiment of the present invention, with a sliding door fully closed; 
         FIG. 1B  is a side view of the automobile with a slide restricting unit activated; 
         FIG. 1C  is a side view of the automobile with the sliding door fully opened; 
         FIG. 2A  is a plane view of parts of the automobile with the sliding door slightly opened; 
         FIG. 2B  is a plane view of the automobile with the slide restricting unit activated; 
         FIG. 2C  is a side view of the automobile with the sliding door fully opened; 
         FIG. 3  is a block diagram of an open/close control system of the sliding door apparatus in the automobile shown in  FIGS. 1A to 1C ; 
         FIG. 4  is a flow chart of processes executed by an open/close controller shown in  FIG. 3 ; 
         FIG. 5A  is a side view of a four-wheeled automobile having a sliding door apparatus according to a second embodiment of the present invention with a sliding door fully closed; 
         FIG. 5B  is a side view of the automobile in  FIG. 5A  with a slide restricting unit activated; 
         FIG. 5C  is a side view of the automobile in  FIG. 5A  with the sliding door fully opened; 
         FIG. 6A  is a plan view of parts of the automobile shown in  FIGS. 5A to 5C  with the sliding door slightly opened; 
         FIG. 6B  is a plane view of the automobile with the slide restricting unit activated; 
         FIG. 6C  is a plane view of the automobile with the sliding door fully opened; 
         FIG. 7  is a block diagram of an open/close control system of the sliding door apparatus in the automobile shown in  FIGS. 5A to 5C ; 
         FIG. 8  is a flow chart of processes executed by an open/close controller shown in  FIG. 7 ; 
         FIG. 9  is a side view of a vehicle having a sliding door apparatus according to a third embodiment of the present invention; 
         FIG. 10  is an exploded perspective view of structural elements of a restricting unit included in the sliding door apparatus shown in  FIG. 9 ; 
         FIG. 11  is a sectional view of the structural elements in an operational state of the restricting unit; 
         FIG. 12  is a sectional view of the structural elements representing another operational state of the restricting unit; 
         FIG. 13  is a sectional view of the structural elements in still another operational state of the restricting unit; 
         FIG. 14  is a side view of a vehicle body having a vehicle door apparatus according to a fourth embodiment of the present invention; 
         FIG. 15  is an illustration of a full closure latch unit viewed from a front side of the vehicle body; 
         FIGS. 16A to 16C  are illustrations of operations of the full closure latch unit; 
         FIG. 17  is a block diagram of a controller; 
         FIG. 18  is a flow chart of processes executed by the controller; and 
         FIG. 19  is an illustration of a full closure latch unit according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present invention are explained in detail below with reference to the accompanying drawings. 
       FIG. 1A  to  FIG. 1C  are schematics of a four-wheeled automobile that employs a sliding door apparatus according to a first embodiment of the present invention. The automobile has a vehicle body  1  of a one-box type, an entrance opening  2 , which allows passengers to get on or off the vehicle, disposed substantially at a center of a side of the vehicle body  1 , and a sliding door  10  provided at the entrance opening  2 . 
     The sliding door  10  is slidably provided on the side of the vehicle body  1  via an upper guiding unit  11  provided at an upper portion of the vehicle body  1 , a lower guiding unit  12  at a lower portion of the vehicle body  1 , and a center guiding unit  13  at a center portion of the vehicle body  1 . The sliding door  10  shuts the entrance opening  2  when slid furthest toward a front of the vehicle body  1  as shown in  FIG. 1A  (hereinafter, “a closed position”). The sliding door  10  opens the entrance opening  2  when slid furthest toward a back of the vehicle body  1  as shown in  FIG. 1C  (hereinafter, “a full-open position”). These guiding units are provided with a support frame  122  having a running roller  121 , which are provided at the sliding door  10  and with a guide rail  123  for guiding the running roller  121 , which is provided on the vehicle body  1 , as shown in  FIG. 2A  to  FIG. 2C . 
     The sliding door  10  includes a window glass  20  serving as an opening/closing member as shown in  FIG. 1 . The window glass  20  is for opening and closing a window hole  14  provided through the slide door  10 . A degree to which the window hole  14  is opened or an openness of the window hole  14  can be adjusted by operation of a window regulator mechanism  15  provided between the window glass  20  and the sliding door  10 . A so-called power window having a regulator switch (not shown) for operating the window regulator mechanism  15  may be employed. The window glass  20  may be moved so as to be closed by rotation of a window motor  15   a  in a first direction with an UP operation of the regulator switch, and so as to be opened by rotation of the window motor  15   a  in a second direction with a DOWN operation of the regulator switch. 
     Between the sliding door  10  and the vehicle body  1 , an automatic sliding unit  30 , full closure latch units  40   f  and  40   r , and a full open latch unit  50  are provided. 
     The automatic sliding unit  30  is configured to activate an actuator in response to an operation made through a door switch provided at a driver&#39;s seat or a passenger&#39;s seat in the vehicle, or at a door handle  16  or a key, so as to allow the sliding door  10  to slide by an action of the actuator. More specifically, a drum  32  is provided on a driving axis of a sliding motor  31  serving as the actuator, and the drum  32  and the support frame  122  are linked by a door-closing wire  33  for moving the sliding door  10  forward and a door-opening wire  34  for moving the sliding door  10  backward. The sliding door  10  is slid in an opening direction to which the sliding door is opened or in a closing direction to which the sliding door is closed, in response to normal rotation/reverse rotation of the sliding motor  31  transmitted to the support frame  122  through the wires  33  and  34 . 
     The full closure latch units  40   f  and  40   r  are for keeping the sliding door  10  at the full-closed position, and are provided at two positions at a front and a back, one of the positions between a front edge portion of the sliding door  10  and the vehicle body  1  and another of the positions between a rear edge portion of the sliding door  10  and the vehicle body  1 . The full open latch unit  50  is for keeping the sliding door  10  at the full-open position, and is provided between the support frame  122  of the lower guiding unit  12  and the vehicle body  1 , as shown in  FIG. 2 , for example. In the first embodiment, the full closure latch units  40   f  and  40   r , and the full open latch unit  50  both include a striker  51  disposed at the vehicle body  1  and a latch  52  disposed at the sliding door  10 , so that the sliding door  10  is kept at a desired position in relation to the vehicle body  1  when the striker  51  and the latch  52  are meshed with each other, as is representatively shown in  FIG. 2 . The meshing engagements between the striker  51  and the latch  52  of these full open latch unit  50  and full closure latch units  40   f  and  40   r  can be released by operating the door switch so as to activate a release actuator (not shown). Of course, the meshing engagements between the striker  51  and the latch  52  in these full open latch unit  50  and full closure latch units  40   f  and  40   r  may be released by operating the door handle  16  provided inside/outside the sliding door  10 . 
     As shown in  FIG. 1  and  FIG. 2 , the sliding door  10  also has a window hole openness detector  60 , as well as a door position detector  70  and a slide restricting unit  80  between the sliding door  10  and the vehicle body  1 . 
     The window hole openness detector  60  detects the openness of the window hole  14  opened and closed as the window glass  20  is moved. In the first embodiment, the openness of the window hole  14  is detected by calculating an amount and a direction of rotation of the window motor  15   a  based on an output pulse from a rotary encoder (not shown) of the window motor  15   a  as shown in  FIG. 1 . A result of the detection is sent to an open/close controller  100 . 
     The door position detector  70  is for detecting a position of the sliding door  10  relative to the vehicle body  1 . As shown in  FIG. 2 , in the first embodiment, the door position detector  70  detects the position by calculating a rotation amount and a rotation direction of the sliding motor  31  based on an output pulse from a rotary encoder (not shown) provided at the sliding motor  31 . A result of the detection of the door position detector  70  is given to the open/close controller  100  as will be described later. 
     The slide restricting unit  80  restricts, when activated before the sliding door  10  reaches the full-open position, sliding of the sliding door  10  in the opening direction relative to the vehicle body  1 . In the first embodiment, the slide restricting unit  80  employs a structure shown in  FIGS. 2A  to  FIG. 2C . A stopper member  81  is pivotably provided at the supporting frame  122  of the lower guiding unit  12 , and an abutting portion  82  is provided at the vehicle body  1 . When the slide restricting unit  80  is not activated, the stopper member  81  is kept at a retracted position as shown in  FIGS. 2A and 2C  so that the stopper member  81  does not interfere with the sliding of the sliding door  10 . On the other hand, when the slide restricting unit  80  is activated as shown in  FIG. 2B , the stopping member  81  is held at an advanced position toward the vehicle body  1  by an actuator (not shown). Accordingly, when the sliding door  10  is slid in the opening direction, the stopper member  81  abuts on the abutting portion  82  of the vehicle body  1 , so as to prevent the sliding door  10  from further sliding. The position at which the stopper member  81  and the abutting portion  82  abut each other (hereinafter “midway position”), as shown in  FIG. 1B  is set so that a safe distance between a front side frame of the window hole  14  and a C pillar  3  of the vehicle body  1  is ensured before the sliding door  10  reaches the full-open position. 
       FIG. 3  is a block diagram of an open/close control system of the sliding door apparatus. The open/close controller  100  controls operation of the slide restricting unit  80  based on the results of the detection by the window hole openness detector  60  and the door position detector  70 . 
       FIG. 4  is a flowchart of processes executed by the open/close controller  100 . The open/close controller  100  constantly monitors the result of the detection by the window hole openness detector  60  and determines whether the openness of the window hole  14  exceeds a threshold (step S 100 ). The threshold is a criterion for the determination, and is preferably as small as possible. The threshold may be 150 mm, for example. 
     If the openness of the window hole  14  detected by the window hole openness detector  60  is 150 mm or less, the open/close controller  100  keeps the slide restricting unit  80  non-activated (step S 101 ). When the slide restricting unit  80  is not activated, since the stopper member  81  is held at the retracted position, the stopper member  81  and the abutting portion  82  do not abut on each other wherever the sliding door  10  is slid to. Therefore, as shown in  FIG. 2A , when the sliding door  10  is in the fully-closed position, by disengaging the striker  51  and the latch  52  of the full closure latch units  40   f  and  40   r , it is possible to slide the sliding door  10  to the full-open position without any trouble. As a result, the entrance opening  2  of the vehicle body  1  is opened widely as shown in  FIG. 2C , and getting on and off the vehicle by passengers and taking baggages in and out the vehicles are facilitated. 
     On the other hand, if the openness of the window hole  14  detected by the window hole openness detector  60  is greater than 150 mm, the open/close controller  100  detects a position of the sliding door  10  relative to the vehicle body  1  via the door position detector  70  (step S 102 ). 
     When the sliding door  10  has already passed the midway position and is before the full-open position, that is, when the window hole  14  is open but a foreign object cannot be put in/out through the open area, or when a foreign object cannot be caught between the open area and the vehicle body  1  even though the foreign object may be put in/out through the open area, the open/close controller  100  proceeds the flow to step S 101  and keeps the slide restricting unit  80  inactivated. Accordingly, it becomes possible to slide the sliding door  10  without any trouble as is the above case. The entrance opening  2  can be widely opened by keeping the sliding door  10  at the full-open position, so that getting on/off of passengers and putting in/out of baggage are facilitated. On the other hand, when the sliding door  10  is slid in the closing direction, the stopper member  81  and the abutting portion  82  will not abut on each other, so that the sliding door  10  can be brought to the full-closed position without any interference to the operation and unpleasant noises during the operation. 
     When the sliding door  10  is between the full-closed position and the midway position at step S 102 , the open/close controller  100  switches the slide restricting unit  80  activated (step S 103 ). As described above, when the slide restricting unit  80  is activated, the stopper member  81  is kept advanced relative to the vehicle body  1 . Therefore, when the sliding door  10  is slid in the opening direction, the stopper member  81  abuts on the abutting portion  82  of the vehicle body  1 , and the sliding door  10  is stopped from sliding at the midway position with a certain distance kept between the front side frame of the opened window hole  14  and the C pillar  3  of the vehicle body  1  as shown in  FIG. 2B . As a result, even if there is the foreign object passing through the open area of the window hole  14 , it is possible to prevent the foreign object from being caught between the window frame and the vehicle body  1 . 
     After the sliding door  10  has stopped at the midway position, when the window glass  20  is closed by the UP operation of the regulator switch so that the openness becomes equal to or less than 150 mm, the flow proceeds to step S 101  from step S 100 , such that the sliding door  10  is allowed to slide to the full-open position again. 
     The open/close controller  100  repeatedly executes the steps described above, activating the slide restricting unit  80  to restrict the sliding door  10  from sliding in the opening direction only when the openness of the window hole  14  is greater than the predetermined threshold and the sliding door  10  is between the full-closed position and the midway position. In other words, if the foreign object cannot be put in/out through the window hole  14 , for example, when the sliding door  10  is already at the full-open position, or if the foreign object cannot be caught between the window frame and the vehicle body  1  even if the foreign object may be put in/out through the window hole  14 , the stopper member  81  will not move to be stuck out. 
     Therefore, for example, when the window hole  14  is largely opened when the sliding door  10  is at the full-open position, and then the sliding door  10  is slid into the closing direction, the stopper member  81  and the abutting portion  82  will not abut on each other, so that unpleasant noises will not be generated as the sliding door is operated, and closing of the sliding door  10  will not be interfered. 
     In the first embodiment, although the sliding door apparatus for opening and closing the entrance opening  2  disposed substantially at the center of the side of the vehicle body  1  of the one box type has been described as an example, the sliding door apparatus may be utilized in opening/closing an opening provided in any other types of vehicles. Further, the sliding door apparatus may not be necessarily provided on the side of the vehicle. Furthermore, although the window glass  20  that opens and closes by the rotation of the window motor  15   a  in response to the operation of the regulator switch has been described as an example of the opening/closing member, the opening/closing member is not necessarily a glass, or driven by a motor. The opening/closing member may be any other members that can open and close the window hole  14  of the sliding door  10 , and the opening/closing member is not necessarily opened/closed in the up-and-down direction. Moreover, although the embodiment in which the window hole openness detector  60  and the door position detector  70  carry out detections based on the output pulses from the rotary encoder (not shown) has been described, the principle of the detections and the specific structures of the detectors are not limited to those of the embodiment. 
     In addition, the threshold of the window hole openness detector  60  is set at 150 mm in the first embodiment, but the threshold may be set at any arbitrary value. For example, by setting the threshold at 0 mm, it is possible to more infallibly prevent any foreign objects from being caught. 
       FIG. 5A  to  FIG. 5C  are schematics of a four-wheeled automobile that employs a sliding door apparatus according to a second embodiment of the present invention. The automobile has a vehicle body  301  of a one-box type, an entrance opening  302 , which allows passengers to get on or off the vehicle, disposed substantially at a center of a side of the vehicle body  301 , and a sliding door  310  provided at the entrance opening  302 . 
     The sliding door  310  is slidably provided on the side of the vehicle body  301  via an upper guiding unit  311  provided at an upper portion of the vehicle body  301 , a lower guiding unit  312  at a lower portion of the vehicle body  301 , and a center guiding unit  313  at a center portion of the vehicle body  301 . The sliding door  310  shuts the entrance opening  302  when slid furthest toward a front of the vehicle body  301  as shown in  FIG. 5A  (hereinafter, “a closed position”). The sliding door  310  opens the entrance opening  302  when slid furthest toward a back of the vehicle body  301  as shown in  FIG. 5C  (hereinafter, “a full-open position”). These guiding units are provided with a support frame  422  having a running roller  221 , which are provided at the sliding door  310  and with a guide rail  423  for guiding the running roller  421 , which is provided on the vehicle body  301 , as shown in  FIG. 6A  to  FIG. 6C . 
     The sliding door  310  includes a window glass  320  serving as an opening/closing member. The window glass  320  is for opening and closing a window hole  314  provided through the slide door  310 . A degree to which the window hole  314  is opened can be adjusted by operation of a window regulator mechanism  315  provided between the window glass  320  and the sliding door  310 . A so-called power window having a regulator switch (not shown) for operating the window regulator mechanism  315  may be employed. The window glass  320  may be moved so as to be closed by rotation of a window motor  315   a  in a first direction with an UP operation of the regulator switch, and so as to be opened by rotation of the window motor  315   a  in a second direction with a DOWN operation of the regulator switch. 
     Between the sliding door  310  and the vehicle body  301 , an automatic sliding unit  330 , full closure latch units  340   f  and  340   r , and a full open latch unit  350  are provided. 
     The automatic sliding unit  330  is configured to activate an actuator in response to an operation made through a door switch provided at a driver&#39;s seat or a passenger&#39;s seat in the vehicle, or at a door handle  316  or a key, so as to allow the sliding door  310  to slide by an action of the actuator. More specifically, a drum  332  is provided on a driving axis of a sliding motor  331  serving as the actuator, and the drum  332  and the support frame  422  are linked by a door-closing wire  333  for moving the sliding door  310  forward and a door-opening wire  334  for moving the sliding door  310  backward. The sliding door  310  is slid in an opening direction to which the sliding door is opened or in a closing direction to which the sliding door is closed, in response to normal rotation/reverse rotation of the sliding motor  331  transmitted to the support frame  422  through the wires  333  and  334 . 
     The full closure latch units  340   f  and  340   r  are for keeping the sliding door  310  at the full-closed position, and are provided at two positions at a front and a back, one of the positions between a front edge portion of the sliding door  310  and the vehicle body  301  and another of the positions between a rear edge portion of the sliding door  310  and the vehicle body  301 . The full open latch unit  350  is for keeping the sliding door  310  at the full-open position, and is provided between the support frame  422  of the lower guiding unit  312  and the vehicle body  301 , as shown in  FIG. 6 , for example. In the second embodiment, the full closure latch units  340   f  and  340   r , and the full open latch unit  350  both include a striker  351  disposed at the vehicle body  301  and a latch  352  disposed at the sliding door  310 , so that the sliding door  310  is kept at a desired position in relation to the vehicle body  301  when the striker  351  and the latch  352  are meshed with each other, as is representatively shown in  FIG. 6 . The meshing engagements between the striker  351  and the latch  352  of these full open latch unit  350  and full closure latch units  340   f  and  340   r  can be released by operating the door switch so as to activate a release actuator (not shown). Of course, the meshing engagements between the striker  351  and the latch  352  in these full open latch unit  350  and full closure latch units  340   f  and  340   r  may be released by operating the door handle  316  provided inside/outside the sliding door  310 . 
     As shown in  FIG. 5  and  FIG. 6 , the sliding door  310  also has a window hole openness detector  360 , as well as a door detector  370 , a slide restricting unit  380 , and a braking unit  390  between the sliding door  310  and the vehicle body  301 . 
     The window hole openness detector  360  detects the openness of the window hole  314  opened and closed as the window glass  320  is moved. In the second embodiment, the openness of the window hole  314  is detected by calculating an amount and a direction of rotation of the window motor  315   a  based on an output pulse from a rotary encoder (not shown) of the window motor  315   a  as shown in  FIG. 5 . A result of the detection is sent to an open/close controller  400 . 
     The door detector  370  is for detecting a position and a speed of the sliding door  310  relative to the vehicle body  301 . As shown in  FIG. 6 , in the second embodiment, the door detector  370  detects the position and the speed by calculating a rotation amount and a rotation direction of the sliding motor  331  based on an output pulse from a rotary encoder (not shown) provided at the sliding motor  331 . A result of the detection of the door detector  370  is given to the open/close controller  400  as will be described later. 
     The slide restricting unit  380  restricts, when activated before the sliding door  310  reaches the full-open position, sliding of the sliding door  310  in the opening direction relative to the vehicle body  301 . In the second embodiment, the slide restricting unit  380  employs a structure shown in  FIG. 6A  to  FIG. 6C . A stopper member  381  is pivotably provided at the supporting frame  422  of the lower guiding unit  312 , and an abutting portion  382  is provided at the vehicle body  301 . When the slide restricting unit  380  is not activated, the stopper member  381  is kept at a retracted position as shown in  FIGS. 6A and 6C  so that the stopper member  381  does not interfere with the sliding of the sliding door  310 . On the other hand, when the slide restricting unit  380  is activated as shown in  FIG. 6B , the stopping member  381  is held at an advanced position toward the vehicle body  301  by an actuator (not shown). Accordingly, when the sliding door  310  is slid in the opening direction, the stopper member  381  abuts on the abutting portion  82  of the vehicle body  1 , so as to prevent the sliding door  310  from further sliding. The position at which the stopper member  381  and the abutting portion  382  abut each other (hereinafter “midway position”), as shown in  FIG. 5B  is set so that a safe distance between a front side frame of the window hole  314  and a C pillar  303  of the vehicle body  301  is ensured before the sliding door  310  reaches the full-open position. 
     The braking unit  390  is for braking the sliding door  310 . In the second embodiment, the braking unit  390  is connected with the drum  332  of the automatic sliding unit  330  via an electromagnetic clutch  391 , applies a load on rotation of the drum  332  when the electromagnetic clutch  391  is brought into a linked state, and brakes the sliding door  310  via the door-closing wire  333  and the door-opening wire  334 . 
       FIG. 7  is a block diagram of an open/close control system of the sliding door apparatus. The open/close controller  400  controls operation of the slide restricting unit  380  and the braking unit  390  based on the results of the detection by the window hole openness detector  360  and the door detector  370 . 
       FIG. 8  is a flowchart of processes executed by the open/close controller  400 . The open/close controller  400  constantly monitors the result of the detection by the window hole openness detector  360  and determines whether the openness of the window hole  314  exceeds a threshold (step S 200 ). The threshold is a criterion for the determination, and is preferably as small as possible. The threshold may be 150 mm, for example. 
     If the openness of the window hole  314  detected by the window hole openness detector  360  is 150 mm or less, the open/close controller  400  keeps the slide restricting unit  380  non-activated (step S 201 ). When the slide restricting unit  380  is not activated, since the stopper member  381  is held at the retracted position, the stopper member  381  and the abutting portion  382  do not abut on each other wherever the sliding door  310  is slid to. Therefore, as shown in  FIG. 6A , when the sliding door  310  is in the full-closed position, by disengaging the striker  351  and the latch  352  of the full closure latch units  340   f  and  340   r , it is possible to slide the sliding door  310  to the full-open position without any trouble. As a result, the entrance opening  302  of the vehicle body  301  is opened widely as shown in  FIG. 6C , and getting on and off the vehicle by passengers and taking baggage in and out the vehicles are facilitated. 
     In the meantime, the open/close controller  400  monitors the position of the sliding door  310  through the door detector  370  (step S 202 ), and determines whether the speed of the sliding door  310  detected by the door detector  370  is greater than a predetermined threshold until the sliding door  310  reaches the full-open position (step S 203 ). 
     When the speed of the sliding door  310  is equal to or less than the threshold, the flow returns to step S 202  without executing the processes described below. When the speed of the sliding door  310  is greater than the threshold, the braking unit  390  is activated until the speed of the sliding door  310  decreases to a value equal to or less than the threshold (step S 204 ). Therefore, even if the sliding door  310  is half-open when the vehicle is inclined, for example, the sliding door  310  will not start moving at a high speed to immediately reach the full-open position and generate a loud noise. 
     When it is detected that the sliding door  310  has reached the full-open position at step S 202 , the flow is ended. 
     If the openness of the window hole  314  is greater than 150 mm at step S 200 , the open/close controller  400  switches the slide restricting unit  380  to an activated state (step S 205 ). Once the slide restricting unit  380  is brought into the activated state, the stopper member  381  is held at the advanced position toward the vehicle body  301 . Accordingly, when the sliding door  310  is slid in the opening direction, the stopper member  381  abuts on the abutting portion  382  of the vehicle body  301 . As a result, as shown in  FIG. 6B , the sliding door  310  is stopped from sliding at the midway position with a predetermined distance between the front side frame of the opened window hole  314  and the C pillar  303  of the vehicle body  301 . In this manner, even if a foreign object is present through the open area of the window hole  314 , it is possible to prevent the foreign object from being caught between the window frame and the vehicle body  301 . 
     In the meantime, the open/close controller  400  monitors the position of the sliding door  310  through the door detector  370  (step S 206 ), and determines whether the speed of the sliding door  310  detected by the door detector  370  is greater than a predetermined threshold until the sliding door  310  reaches the midway position (step S 207 ). 
     When the speed of the sliding door  310  is equal to or less than the threshold, the flow returns to step S 206  without executing the steps described below. When the speed of the sliding door  310  is greater than the threshold, the braking unit  390  is activated until the speed of the sliding door  310  is decreased to a value equal to or less than the threshold (step S 208 ). Therefore, even if the sliding door  310  is half-open when the vehicle is inclined for example, the sliding door  310  will not start moving at a high speed to immediately reach the midway position, generate a loud noise, and damage the slide restricting unit  380 . 
     When it is detected that the sliding door  310  has reached the midway position at step S 206 , that is, when it is detected that the sliding door  310  is stopped at the midway position by the slide restricting unit  380 , the flow is ended. 
     The open/close controller  400  then repeatedly executes the above steps, such that sliding of the sliding door  310  in the opening direction is restricted by activating the slide restricting unit  380  when the openness of the window hole  314  is greater than the predetermined threshold. Accordingly, even if a foreign object is put out through the window hole  314 , it is possible to prevent the foreign object from being caught between the window frame and the vehicle body  301 , so that the sliding door  310  is more user-friendly. Additionally, when the sliding door  310  starts moving at a high speed, the braking unit  390  is activated so as to reduce the speed. Accordingly, it is possible to infallibly prevent generation of noises and damages to the slide restricting unit  380  when the sliding door  310  is stopped half-open. 
     In the second embodiment, although the sliding door apparatus for opening and closing the entrance opening  302  disposed substantially at the center of the side of the vehicle body  301  of the one box type has been described as an example, the sliding door apparatus may be utilized in opening/closing an opening provided in any other types of vehicles. Further, the sliding door apparatus may not be necessarily provided on the side of the vehicle. Furthermore, although the window glass  320  that opens and closes by the rotation of the window motor  315   a  in response to the operation of the regulator switch has been described as an example of the opening/closing member, the opening/closing member is not necessarily a glass, or driven by a motor. The opening/closing member may be any other members that can open and close the window hole  314  of the sliding door  310 , and the opening/closing member is not necessarily opened/closed in the up-and-down direction. Moreover, although the embodiment in which the window hole openness detector  360  and the door detector  370  carry out detections based on the output pulses from the rotary encoder (not shown) has been described, the principle of the detections and the specific structures of the detectors are not limited to those of the embodiment. 
     In addition, although the embodiment in which the slide door apparatus having the slide restricting unit  380  has been described, the sliding door apparatus does not necessarily have the slide restricting unit  380 . What is more, the threshold of 150 mm has been used in the second embodiment, but the threshold may be set at any arbitrary value. For example, by setting the threshold at 0 mm, it is possible to more infallibly prevent any foreign objects from being caught. 
       FIG. 9  is a side view of a vehicle that adopts a sliding door apparatus according to a third embodiment of the present invention. In  FIG. 9 , a sliding door apparatus  510  includes a sliding door  520  and a restricting unit  540 . 
     The sliding door  520  is disposed on a side of a vehicle body  501  of a four-wheeled automobile such as a “one-box” van. This sliding door  520  is capable of sliding along a fore-and-aft direction of the vehicle body  501 . To be more specific, the sliding door  520  is engaged with a rail  503  provided approximately parallel to the fore-and-aft direction of vehicle body  501  on the side of the vehicle body  501 . The sliding door  520  slides along the rail  503  in the fore-and-aft direction, so as to open/close an opening  501   a  on the side of the vehicle body  501 . In the illustrated example, the opening  501   a  is closed, that is, the sliding door  520  is fully closed. 
     The sliding door  520  includes a window hole  521  at an upper portion of the sliding door  520 . The window hole  521  can be opened/closed by up-and-down movement of a window glass  522 . In the present specification, the window hole  521  is in a closed state when the window glass  522  is at the upper dead end and in an open state when the window glass  522  has moved down by a predetermined amount from the upper dead end. The up-and-down movement of the window glass  522  is achieved by a window regulator  523 . A power window regulator of an X-arm type is used as the window regulator  523  in the second embodiment. 
     The window regulator  523  includes a lifting arm  731 , a first movable arm  732 , and a second movable arm  733 . The lifting arm  731  has a roller (not shown) at a distal end portion  731   a  of the lifting arm  731  and an arm driving unit (displacing mechanism)  730  at a proximal end portion  731   b  of the lifting arm  731 . The roller is engaged with a guide portion (not shown) of a first supporting member  735  fixed at a lower end of the window glass  522  so as to be movable in a horizontal direction. The arm driving unit  730  has a motor inside, and is configured to swing the lifting arm  731 . In a middle portion of the lifting arm  731 , a spindle  736  is rotatably provided so as to pass through the lifting arm  731 . 
     The first movable arm  732  has a distal end portion  732   a  with a roller (not shown) and a proximal end portion  732   b  fixed to the spindle  736 . The roller is engaged with the guide portion of the first supporting member  735  so as to be movable in the horizontal direction. Therefore, the first movable arm  732  is able to swing about the axial center of the spindle  736 . 
     The second movable arm  733  has a distal end portion  733   a  with a roller (not shown) and a proximal end portion  733   b  fixed to the spindle  736 . The roller is disposed on an inner panel (not shown) of the sliding door  520  and is engaged with a guide portion (not shown) of a second supporting member  737  which is parallel with the first supporting member  735 , so as to be movable in the horizontal direction. Therefore, the second movable arm  733  is able to swing about the axial center of the spindle  736 . 
     That is, the window regulator  523  moves up/down the window glass  522  by displacing the first supporting member  735  in a direction of leaving or approaching the second supporting member  737  with the lifting arm  731 , the first movable arm  732  and the second movable arm  733  driven by the arm driving unit  730 . The window regulator  523  may be of a manual type such that the arm driving unit  730  can be manually driven. 
     On the other hand, to the arm driving unit  730  an end portion of a cable C as a restiform member (see  FIGS. 11 to 13 ) is latched. Another end portion of the cable C is, as will be described in detail, latched to a part of the restricting unit  540 . The arm driving unit  730  is activated to draw in the cable C. More specifically, the arm driving unit  730  draws in the cable C when the arm driving unit  730  drives down the window glass  522  which is at the upper dead end. When the arm driving unit  730  is to drive up the window glass  522 , the cable C is freed. 
     The restricting unit  540  is disposed at a lower portion of the sliding door  520 . More specifically, the restricting unit  540  is supported by a fixed bracket (not shown) provided at a predetermined position in the lower portion of the sliding door  520 .  FIGS. 10 to 13  are illustrations of elements of the restricting unit of the sliding door apparatus according to the third embodiment.  FIG. 10  is an exploded perspective view of the elements, and  FIGS. 11 to 13  are cross sections of the elements in different operational states of the restricting unit. In  FIGS. 10 to 13 , the restricting unit  540  includes a first movable member  541  and a second movable member  542 . 
     The first movable member  541  is disposed swingably on a base plate  543  of the fixed bracket. To be more specific, a supporting rod  544  inserted in a hole  543   a  of the base plate  543  is inserted in a through hole  541   b  at a proximal portion  541   a  of the first movable member  541  such that the first movable member  541  is able to swing about the axial center of the supporting rod  544 . 
     To a first latch piece  541   d  at an end portion  541   c  of the first movable member  541 , another end portion of the cable C is latched. That is, the first movable member  541  is mechanically connected with the arm driving unit  730  via the cable C. Further, to this first latch piece  541   d  one end portion  545   a  of a first coil spring  545  is latched. The first coil spring  545  is wound around the supporting rod  544 , and another end portion  545   b  of the first coil spring  545  is latched to a stopper rod  546  fixed to the base plate  543 . The first coil spring  545  applies a force on the first movable member  541  in a direction of an arrow N 1  in  FIG. 11  (clockwise direction), and a side edge of the base part  541   a  abuts on the stopper rod  546 . 
     The second movable member  542  is disposed on the base plate  543  so as to be able to swing, between the base plate  543  and the first movable member  541 . To be more specific, the supporting rod  544  is inserted in a through hole  542   b  at a base portion  542   a  of the second movable member  542  such that the second movable member  542  is able to swing and the end portion  542   c  is able to move toward/away from the vehicle body  501 . 
     To a second latch piece  541   f  located at a protrusion  541   e  which protrudes from the base portion  541   a  of the first movable member  541 , and a spring latch piece  542   e  located at a protrusion  542   d  which protrudes from the base part  542   a  of the second movable member  542 , one end portion  547   a  and another end portion  547   b  of a second coil spring  547  are latched. The second coil spring  547  is wound around the supporting rod  544  similarly to the first coil spring  545 . Positional relationship between the first movable member  541  and the second movable member  542  is defined such that by the force applied by the second coil spring  547  the protrusions  541   e  and  542   d  (the second latch piece  541   f  and the spring latch piece  542   e ) are overlapped with each other. Therefore, in a normal state of the second movable member  542 , the protrusion  542   d  is overlapped with the protrusion  541   e  of the first movable member  541  (See  FIG. 11 ). As is the same with the first movable member  541 , the first coil spring  545  applies a force on the second movable member  542  in the direction of the arrow N 1  in  FIG. 11 . Accordingly, in the normal state of the second movable member  542 , the end portion  542   c  is retracted in relation to the vehicle body  501 . In other words, the end portion  542   c  of the second movable member  542  is accommodated in the sliding door  520  indicated by a chain double-dashed line in  FIG. 11 . 
     Next, operation of the sliding door apparatus  510  will be explained. For convenience of explanation, the sliding door  520  is assumed to be fully closed initially. 
     When the window glass  522  is at the upper dead end and the window hole  521  is closed, the arm driving unit  730  of the window regulator  523  is not activated and does not draw in the cable C. Therefore, in the restricting unit  540 , the first movable member  541  and the second movable member  542  are held at positions shown in  FIG. 11  by the force in the direction of the arrow N 1  applied by the first coil spring  545 , with the side edge of the end portion  541   c  of the first movable member  541  abutting on the stopper rod  546 . At this time, the end portion  542   c  of the second movable member  542  is retracted in relation to vehicle body  501 . That is, the end portion  542   c  is accommodated in the sliding door  520 . In other words, the second movable member  542  is positioned at a retracted position relative to the vehicle body  501 . If the sliding door  520  is operated to fully open in such a state, the sliding door  520  slides in the backward direction of the vehicle body  501  to be fully opened. 
     On the other hand, he window glass  522  is moved down from the upper dead end, when the sliding door  520  is initially fully closed, the window hole  521  is also closed, and the window regulator  523  is driven by driving of the arm driving unit  730 . The arm driving unit  730  draws in the cable C. The cable C is thus displaced by an amount corresponding to an extent to which the cable C is drawn in by the arm driving unit  730  (hereinafter also referred to as a “drawn-in amount”). By such displacement of the cable C, the restricting unit  540  is operated as described below. 
     As shown in  FIG. 12 , the first movable member  541  of the restricting unit  540  swings in the direction of the arrow N 1  against the force applied by the first coil spring  545 . As a result, since the protrusion  542   d  is overlapped with the protrusion  541   e  of the first movable member  541  by the force applied by the second coil spring  547 , the second movable member  542  of the restricting unit  540  swings in the direction of an arrow N 2  depending on the swinging motion of the first movable member  541  while keeping the overlapped state. 
     The side edge of the end portion  542   c  of the second movable member  542  having swung in the direction of the arrow N 2  then abuts on the stopper rod  546  and stops swinging. At this time, the end portion  542   c  of the second movable member  542  is advanced in relation to the vehicle body  501 . That is, the end portion  542   c  is protruded toward the vehicle body  501  from the sliding door  520  as denoted by the chain double-dashed line in  FIG. 12 . In other words, the second movable member  542  is positioned at an advanced position relative to the vehicle body  501 . An amount of swinging from the retracted position to the advanced position of the second movable member  542  is associated in advance with an amount by which the window glass  522  is moved down from the upper dead end, namely with the openness of the window hole  521 . When the openness of the window hole  521  exceeds a predetermined magnitude, the second movable member  542  is defined to be positioned at the advanced position. 
     When the sliding door  520  is operated to fully open when the second movable member  542  is at the advanced position, the sliding door  520  slides in the backward direction of the vehicle body  501 . However, the end portion  542   c  of the second movable member  542  comes into abutment with an abutting block (not shown) arranged at a predetermined position of the vehicle body  501 , so that the sliding door  520  is restricted from being fully opened. The abutting block is provided at such a position that the whole of the window hole  521  of the sliding door  520  can be prevented from crossing a pillar  504  of the vehicle body  501  (see  FIG. 9 ) by sliding of the sliding door  520 . 
     On the other hand, when the window glass  522  is moved up to the upper dead end to close the window hole  521 , the arm driving unit  730  releases the cable C. It is assumed that the second movable member  542  of the restricting unit  540  here is at the advanced position as shown in  FIG. 12  for convenience of the explanation. In the restricting unit  540 , the first movable member  541  and the second movable member  542  swing in the direction of the arrow N 1  by the force applied by the first coil spring  545 . As a result, the second movable member  542  is positioned at the retracted position, and the end portion  542   c  of the second movable member  542  is retracted in relation to the vehicle body  501  (See  FIG. 11 ). 
     As described above, in the second movable member  542 , the amount of swinging from the retracted position to the advanced position is a total amount of swinging. In the restricting unit  540 , product-to-product variation may cause variation in a relationship between the total amount of swinging and the draw-in amount of the cable C. Accordingly, to ensure that the end portion  542   c  of the second movable member  542  is advanced relative to the vehicle body  501 , the draw-in amount of the cable C by the arm driving unit  730  (displacement of the cable C) is preferably larger than the total amount of swinging of the second movable member  542 . Therefore, the draw-in amount of the cable C by the arm driving unit  730  is set to be larger than the total amount of swinging of the second movable member  542 . 
     When the draw-in amount of the cable C by the arm driving unit  730  is larger than the total swinging amount of the second movable member  542 , as shown in  FIG. 13 , the first movable member  541  of the restricting unit  540  swings in the direction of the arrow N 2  in  FIG. 13  against the force applied by the second coil spring  547 , independently of the second movable member  542 . At this time, the first movable member  541  swings until the protrusion  541   e  abuts on the stopper rod  546 . 
     In summary, in the sliding door apparatus  510  according to the third embodiment of the present invention, the first movable member  541  and the second movable member  542  serve as the abutting portion to be abutted on the abutting block which is the predetermined portion of the vehicle body  501 . The first coil spring  545  serves as the forcing unit, which applies the force on the second movable member  542  so as to hold the second movable member  542  at the retracted position relative to the vehicle body  501 . The second coil spring  547  links the first movable member  541  and the second movable member  542  when the second movable member  542  swings from the retracted position to the advanced position, while serving as the permitting unit which permits the first movable member  541  to swing in relation to the second movable member  542  after the second movable member  542  has swung to the advanced position. 
     Further, the restricting unit  540  can be held at the retracted position relative to the vehicle body  501  as the first coil spring  545  applies the force on the first movable member  541  and the second movable member  542 . The restricting unit  540  can be also held at the advanced position where the end portion  542   c  of the second movable member  542  is advanced relative to the vehicle body  501  against the force applied by the first coil spring  545  when the arm driving unit  730  draws in the cable C and the openness of the window hole  521  exceeds the predetermined magnitude. Therefore, even if the force by the first coil spring  545  is weakened due to adhesion of mud or water to the first coil spring  545 , in the restricting unit  540 , the end portion  542   c  of the second movable member  542  can be infallibly held at the advanced position relative to the vehicle body  501 . Therefore, for fully opening the sliding door  520  in which the window hole  521  is opened by the openness exceeding the predetermined magnitude, the end portion  542   c  of the second movable member  542  can infallibly abut on the abutting block, so that the sliding door  520  can be infallibly restricted from being fully opened. Accordingly, even if the sliding door  520  is operated to fully open with an object passing through the window hole  521 , the object will not be caught between the window frame of the window hole  521  and the pillar  504  of the vehicle body  501  and hence damages are prevented. 
     Furthermore, according to the sliding door apparatus  510 , the second coil spring  547  on one hand links the first movable member  541  and the second movable member  542  when the second movable member  542  swings from the retracted position to the advanced position. On the other hand, the second coil spring  547  allows the first movable member  541  to swing in relation to the second movable member  542  after the second movable member  542  has swung to the advanced position. As a result, even if product-to-product variation causes variation in the relationship between the total swinging amount of the second movable member  542  and the draw-in amount of the cable C, the end portion  542   c  of the second movable member  542  can be infallibly brought to the advanced position relative to the vehicle body  501 . 
     Although an example of preferred embodiments of the present invention has been described, it is to be understood that the present invention is not limited to this embodiment. For example, the openness of the window hole may be detected by a detector such as a sensor, and the cable may be drawn in according to a result of this detection. 
     A vehicle door apparatus according to a fourth embodiment of the present invention as shown in  FIG. 14  is applied to a sliding door  802  which is a door provided on a side of a vehicle body  801 . The sliding door  802  is engaged with a rail  803  provided approximately parallel with the fore-and-aft direction of the vehicle body  801  on the side of the vehicle body  801 . The sliding door  802  is slidably guided in the fore-and-aft direction of the vehicle body  801  along the rail  803  to open/close an opening  801   a  on the side of the vehicle body  801 . In  FIG. 14 , the sliding door  802  is closed. 
     The vehicle body  801  and the sliding door  802  are provided with a full closure latch unit configured to bring the sliding door  802  into engagement with the vehicle body  801  so as to open/close the opening  801   a .  FIG. 15  is an illustration of the full closure latch unit viewed from the front of the vehicle body, and  FIGS. 16A to 16C  are conceptual views of operation of the full closure latch unit. 
     As shown in  FIG. 15 , the full closure latch unit has a latch mechanism unit  804  disposed at the sliding door  802 . The latch mechanism unit  804  on one hand keeps the sliding door  802  closed by meshing with a striker S provided at the vehicle body  801 . The latch mechanism unit  804  on the other hand permits the sliding door  802  to slide in the opening direction by releasing the striker S meshed. This latch mechanism unit  804  includes a latch  806  and a ratchet  807  in an accommodating unit  805 . The accommodating unit  805  has a horizontal notch groove  805   a  extending from the interior to the exterior of the vehicle body  801 , at an approximate midpoint of a height of the accommodating unit  805 . 
     The latch  806  is rotatably provided via a latch axis  808  extending approximately horizontally along the fore-and-aft direction of the vehicle body  801 , at a position higher than the horizontal notch groove  805   a  of the accommodating unit  805 . The latch  806  has a meshing groove  806   a , a hook  806   b , a full-latch latching portion  806   c , and a half-latch latching portion  806   d  along a circumference of the latch  806 . 
     The meshing groove  806   a  is formed from an outer peripheral surface of the latch  806  toward the latch axis  808  and has a width which can accommodate the striker S. The hook  806   b  is a part located closer to the interior of the vehicle body  801  than the meshing groove  806   a  when the meshing groove  806   a  is opened downward. The full-latch latching portion  806   c  is located closer to the exterior of the vehicle body  801  than the meshing groove  806   a  when the meshing groove  806   a  is opened downward. The half-latch latching portion  806   d  is located toward the exterior and diagonally downward when the meshing groove  806   a  is opened diagonally downward toward the interior of the vehicle body  801 . 
     The latch  806  is always applied with a force in the clockwise direction in  FIG. 15  by a member such as a spring member (not shown). 
     The latch axis  808  has a latch detector  809 . The latch detector  809  detects a position of the latch  806  based on rotation of the latch axis  808  due to rotation of the latch  806 . 
     The ratchet  807  is rotatably provided at a position lower than the horizontal notch groove  805   a  of the accommodating unit  805  so that the ratchet  807  can rotate via a ratchet axis  810  extending approximately horizontally along the fore-and-aft direction of the vehicle body  801 . The ratchet  807  has an engaging portion  807   a  and a power action unit  807   b  along a circumference of the ratchet  807 . 
     The engaging portion  807   a  extends in the radial direction from the ratchet axis  810  toward the exterior of the vehicle body  801 . When the ratchet  807  is rotated in the clockwise direction in  FIG. 15 , the engaging portion  807   a  can engage with the full-latch latching portion  806   c  and the half-latch latching portion  806   d  of the latch  806  described above via a projecting end surface of the engaging portion  807   a . The power action unit  807   b  extends in the radial direction toward the exterior of the vehicle body  801  from the ratchet axis  810 . 
     The above ratchet  807  is always applied with a force in the counterclockwise direction in  FIG. 15  by a member such as a spring member (not shown). 
     The ratchet  807  is linked with an outside handle  802   a  disposed on the exterior side of the sliding door  802  or an inside handle disposed on the interior side of the sliding door  802 , and rotates in the clockwise direction against the force applied by the spring member by an operation through the handle. The configuration for linking the outside handle  802   a  and the inside handle with the ratchet  807  is the same as that previously described, and so the explanation will be omitted. 
     In the latch mechanism unit  804 , the latch  806  rotates in the clockwise direction by the force as shown in  FIG. 16A  when the sliding door  802  is opened in relation to the vehicle body  801 . In this case, an unlatched state is established in which the hook  806   b  releases the horizontal notch groove  805   a  so as to allow the striker S to advance/retract (be removed) to/from the horizontal notch groove  805   a . If the sliding door  802  is operated to close from the unlatched state, the striker S provided at the vehicle body  801  enters the horizontal notch groove  805   a , so that the striker S abuts on the full-latch latching portion  806   c . As a result, the latch  806  rotates in the counterclockwise direction against the clockwise force while the ratchet  807  rotates about the axial center of the ratchet axis  810  according to the shape of the outer peripheral surface of the latch  806  as the projecting end surface of the engaging portion  807   a  slides in contact with the outer peripheral surface of the latch  806 . 
     When the sliding door  802  is further operated to close from the state as described above, the striker S enters further into the horizontal notch groove  805   a  gradually to cause the latch  806  to further rotate in the counterclockwise direction, and then the engaging portion  807   a  of the ratchet  807  reaches to the half-latch latching portion  806   d  of the latch  806  as shown in  FIG. 16B . In this state, since the half-latch latching portion  806   d  is abutted on the engaging portion  807   a , rotation in the clockwise rotation of the latch  806  by the force is inhibited. In addition, since the hook  806   b  of the latch  806  is arranged to traverse the horizontal notch groove  805   a , the striker S is prevented from moving in the direction of leaving the horizontal notch groove  805   a , or the sliding door  802  is prevented from opening in relation to the vehicle body  801  by the hook  806   b . As a result, the sliding door  802  is latched to the vehicle body  801  and kept in a half-door state (half latch position). 
     When the sliding door  802  is further operated to close from the aforementioned half-latch state, the latch  806  is rotated further in the counterclockwise direction via the full-latch latching portion  806   c  by the striker S entering the horizontal notch groove  805   a , and the striker S reaches the end (the exterior side of the vehicle body) of the horizontal notch groove  805   a . During this motion, the outer peripheral surface connecting the half-latch latching portion  806   d  and the full-latch latching portion  806   c  of the latch  806  slides in contact with a top surface of the engaging portion  807   a  so that the ratchet  807  is rotated in the clockwise direction in  FIG. 16  against the force and begins to rotate in the counterclockwise direction immediately after the full-latch latching portion  806   c  of the latch  806  has passed the ratchet  807 . As a result, as shown in  FIG. 16C , since the full-latch latching portion  806   c  of the latch  806  comes into abutment with the engaging portion  807   a  of the ratchet  807 , clockwise rotation of the latch  806  by the force is prevented. In this state, since the hook  806   b  is arranged so as to traverse the horizontal notch groove  805   a , the striker S is prevented from moving in the direction of leaving the end of the horizontal notch groove  805   a  by the hook  806   b , so that the sliding door  802  is latched to the vehicle body  801  and kept in a full closed state (full latch position). In the fourth embodiment, a term “closed state” includes the “half-door state” in which the latch mechanism unit  804  is at the half latch position and the “full closed state” in which the latch mechanism unit  804  is at the full latch position. 
     At the full latch position or the half latch position, when the outside handle  802   a  or the inside handle (not shown) is operated, the ratchet  807  rotates in the clockwise direction in  FIG. 16  against the force. As a result, the full-latch latching portion  806   c  (or the half-latch latching portion  806   d ) of the latch  806  is released from abutting engagement with the engaging portion  807   a  of the ratchet  807 , and the latch  806  is rotated in the clockwise direction in  FIG. 16  by the force. As a result, as shown in  FIG. 16A , the horizontal notch groove  805   a  is released so as to allow the striker S to move in the direction of leaving the horizontal notch groove  805   a , so that the sliding door  802  is ready to be operated to open in relation to the vehicle body  801 . 
     The unlatched state, full latch position, or half latch position as described above is detected by the latch detector  809  serving as a door detector provided at the latch axis  808 . 
     As shown in  FIG. 15 , the accommodating unit  805  accommodating the latch mechanism unit  804  is provided with a door releasing mechanism  812  serving as a latch releasing unit of the full closure latch unit. The door releasing mechanism  812  has a motor  813 , an idling gear  814 , a first transmission gear  815 , a second transmission gear  816 , a sector gear  817 , a lever shaft  818 , and a releasing lever  819 . 
     The motor  813  is configured so that an output axis  813   a  is rotatable in both the clockwise and counterclockwise directions in  FIG. 15 . To the output axis  813   a  a driving gear  813   b  is attached. 
     The idling gear  814  is rotatably attached to the accommodating unit  805 . The idling gear  814  has a large-diameter gear wheel  814   a  configured to mesh with a driving gear  813   b  of the motor  813  and a small-diameter gear wheel  814   b , which are formed coaxially and may be unitary. 
     The first transmission gear  815  is rotatably attached to the accommodating unit  805 . The first transmission gear  815  has a toothed outline configured to mesh with the small-diameter gear wheel  814   b  of the idling gear  814 . The first transmission gear  815  has a recess  815   a  at a center portion of the first transmission gear  815 . 
     The second transmission gear  816  has a flange  816   a  that fits in the recess  815   a  of the first transmission gear  815 , and is attached coaxially to the first transmission gear  815 . The second transmission gear  816  includes a fan-shaped projection  816   b  extending in the radial direction with respect to the axis of the second transmission gear  816  and a gear  816   c  at the projection  816   b.    
     The sector gear  817  is rotatably attached to the accommodating unit  805  by the lever shaft  818 . The sector gear  817  includes a gear  817   a  that meshes with the gear  816   c  of the second transmission gear  816 . 
     The releasing lever  819  is rotatably attached to the accommodating unit  805  by the lever shaft  818 . The releasing lever  819  is configured to be engageable with the power action unit  807   b  of the ratchet  807 . 
     According to the above door releasing mechanism  812 , the power generated by the motor  813  is transmitted sequentially to the driving gear  813   b , the idling gear  814 , the first transmission gear  815 , the second transmission gear  816 , the sector gear  817 , the lever shaft  818 , and the releasing lever  819 . The releasing lever  819  is then swung in the counterclockwise direction in  FIG. 15 . When the releasing lever  819  swings in the counterclockwise direction in  FIG. 15 , the ratchet  807  swings in the clockwise direction in  FIG. 15  to cancel the engagement between the ratchet  807  and the latch  806  at the full latch position and the half latch position. In this manner, the door releasing mechanism  812  rotates the ratchet  807  by the power of the motor  813  to bring the latch  806  into the unlatched state. In other words, the door releasing mechanism  812  permits the sliding door  802  to slide in the opening direction. 
     As shown in  FIG. 14 , the sliding door  802  is provided with a window hole  821 . The window hole  821  allows opening/closing of a window hole opening  821   a  provided in the sliding door  802 . Opening/closing of the window hole  821  is achieved by a regulator  822 . In the fourth embodiment, a power window regulator of an X-arm type is used as the regulator  822  as an example. In this case, the regulator  822  drives the lifting arm  822   b  to be swung with an arm driving unit  822   a  having a motor or the like. A swinging end of the lifting arm  822   b  is movably engaged along a longitudinal supporting member  822   c  fixed to a lower end portion of the window hole  821 . The lifting arm  822   b  has a pair of movable arms  822   d  at a midway portion of the lifting arm  822   b . A proximal end of one of the movable arms  822   d  is supported at a first position by the lifting arm  822   b  and a distal end of the movable arm  822   d  is movably engaged along the longitudinal supporting member  822   c . A proximal end of another one of the movable arms  822   d  is supported coaxially with respect to the first position, and a distal end of the another one of the movable arms  822   d  is movably engaged with a supporting member  822   e  fixed approximately in parallel with the supporting member  822   c  to the sliding door  802 . That is, for opening the window hole  821 , the regulator  822  drives the arm driving unit  822   a  to cause the lifting arm  822   b  and the respective movable arms  822   d  to displace the supporting member  822   c  downward in relation to the supporting member  822   e . For closing the window hole  821 , the regulator  822  drives the arm driving unit  822   a  to cause the lifting arm  822   b  and the respective movable arms  822   d  to displace the supporting member  822   c  upward in relation to the supporting member  822   e.    
     The above regulator  822  may be of a type configured to be able to manually drive the arm driving unit  822   a.    
     The fact that the window hole  821  is opened by the regulator  822  may be detected by a window hole detector  823 . The window hole detector  823  may be of any type, such as a type configured to detect moving down of the window hole  821  or a type configured to detect downward driving of the regulator  822 . The window hole detector  823  may detect that the window hole  821  is open according to an operation of an opening switch of a power window, if the regulator  822  is of an automatic power window. 
     Next, control for preventing closing of the window hole  821  that has been opened by the regulator  822  from being forgotten is explained. 
       FIG. 17  is a block diagram of a controller that prevents the closing of the window hole from being forgotten. A controller  825  includes a processor (such as a CPU), a RAM for storing input data, and a ROM for storing control procedure. To the controller  825 , the latch detector  809 , the window hole detector  823 , the door releasing mechanism  812 , and a notifying unit  826  are connected. In the fourth embodiment, the latch detector  809  detects the operational state of the full closure latch unit only from the position of the latch  806 . However the operational state of the full closure latch unit may be detected from the position of the ratchet  807 . 
     The controller  825  receives a detection signal from the latch detector  809  having detected the position of the latch  806  in the latch mechanism unit  804  (the unlatched state, half latch position, and full latch position). Also the controller  825  receives a detection signal from the window hole detector  823  having detected that the window hole  821  is opened by the regulator  822 . The controller  825  outputs a driving signal for rotating the ratchet  807  of the latch mechanism unit  804  to the door releasing mechanism  812 . The controller  825  then outputs a driving signal to the notifying unit  826  for notifying a user/passenger with a sound, light, or the like. 
       FIG. 18  is a flowchart of control for preventing closing of the window hole from being forgotten. First, when the window hole  821  is detected to be open (step S 301 : Yes) and the sliding door  802  is detected to be open (step S 302 : Yes), these two results of detection are stored. When the sliding door  802  is placed in the closed state (step S 303 : Yes), the door releasing mechanism  812  is activated to close the door, so that the latch  806  is brought into the unlatched state and the closed state of the sliding door  802  is cancelled, the notifying unit  826  notifies the user (step S 304 ), and the control is ended. 
     In step S 302 , the opened state of the sliding door  802  can be determined by detecting the unlatch state with the latch detector  809  serving as the door detector. In step S 303 , the closing operation of the sliding door  802  can be determined by detecting the half latch position or the full latch position with the latch detector  809  serving as the door detector. Step S 301  may be performed after step S 302  instead. If the window hole  821  is closed after ending the control, the sliding door  802  can be closed. 
     When the window hole  821  is open (step S 301 : Yes) and the sliding door  802  is open (step S 302 : Yes), instead of proceeding to step S 303 , the controller  825  may activate the door releasing mechanism  812  so as to open the sliding door  802 , notify the user (step S 304 ), and end the control. 
     The vehicle door apparatus may have in the full closure latch unit an auto-closer function that drives the latch  806  to the full latch position upon detection of the half latch position by the latch detector  809 , for closing the sliding door  802 . Such an auto-closer function is cancelled so as not to be activated when the window hole  821  and the sliding door  802  are open (after steps S 301  and S 302 ). 
     As described above, the vehicle door apparatus has a door closure preventing unit configured to prevent the sliding door  802  from being closed. This door closure preventing unit includes the window hole detector  823  that detects the open state of the window hole  821 , the door detector (the latch detector  809 ) that detects the open state of the sliding door  802 , the full closure latch unit (the latch mechanism unit  804  and the door releasing mechanism  812 ), and the controller that activates the full closure latch unit so as to open the door based on detection signals input from the window hole detector and the door detector. Accordingly, when the sliding door  802  is open while the window hole  821  is also open, the door closure preventing unit activates the full closure latch unit to open the door, so as to prevent the sliding door  802  from being closed. As a result, the passenger is able to recognize that he/she has forgetten to close the window hole  821 , and the passenger is prevented from leaving the vehicle with the window hole  821  open. 
     Further, the notifying unit  826  notifies the passenger so as to allow the passenger to recognize clearly that the passenger has forgotten to close the window hole  821 . 
     The fourth embodiment has been described with the door closure preventing unit which prevents the sliding door  802  from being closed using the door releasing mechanism  812  when the sliding door  802  and the window hole  821  are open. However, the door closure preventing unit may be of a type, which prevents the sliding door  802  from being closed without using the door releasing mechanism  812 . 
     More specifically, as shown in  FIG. 19 , the latch mechanism unit  804  may be provided with a restricting rod  830  configured to abut on the latch  806  in the unlatched state so as to disable the latch  806  in the unlatched state to rotate to the half latch position and full latch position. The restricting rod  830  is able to move to/from the latch  806  via a link mechanism, an actuator, or the like (not shown). When the window hole detector  823  determines that the window hole  821  is open and the latch detector  809  determines that the sliding door  802  is open, the restricting rod  830  is advanced toward the latch  806  (from the position indicated by the dashed dotted line to the position indicated by the solid line) in  FIG. 19  so as to restrict counterclockwise rotation of the latch  806  and keep the latch mechanism unit  804  in the unlatched state. 
     The rail  803  may have a restricting member  831  that abuts on the sliding door  802  as shown in  FIG. 14  so that the sliding door  802  open is not closed. The restricting member  831  is able to advance/retract to/from the rail  803  via a link mechanism or an actuator (not shown). When the window hole detector  823  detects that the window hole  821  is open and the latch detector  809  detects the sliding door  802  is open, the restricting member  831  is caused to advance into the rail  803  to restrict the sliding door  802  from closing, such that the latch mechanism unit  804  is kept in the unlatched state. 
     According to the vehicle door apparatus, it is possible to prevent the sliding door  802  from being closed when the sliding door  802  is open and the window hole  821  is open, so that the passenger is able to recognize that she/he has forgotten to close the window hole  821  and the passenger is prevented from closing the door with the window hole open. 
     In the fourth embodiment, the latch detector  809  determines the sliding door  802  to be open by detecting the unlatched state, but this may be determined by ON/OFF of a switch or the like serving as the door detector that directly detects opening of the sliding door  802 . 
     Further, the embodiment is not limited to be utilized in the sliding door  802 , but may be also applied to any other door having an openable/closable window hole such as a side door that opens via a hinge, or a back door of hatchback vehicle body, so as to prevent the passenger from forgetting to close the window hole. 
     Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.