Patent Publication Number: US-6707375-B2

Title: Keyless entry apparatus capable of selectively controlling only member to be controlled closest to user

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to keyless entry apparatuses, and more particularly, to a keyless entry apparatus for controlling a member to be controlled of a vehicle by an answer signal which a portable transmitting and receiving device transmits when the portable transmitting and receiving device receives a request signal transmitted from an on-vehicle transmitting and receiving device. 
     2. Description of the Related Art 
     Each of conventional keyless entry apparatuses is formed of an on-vehicle transmitting and receiving device mounted on a vehicle and a portable transmitting and receiving device carried by a user. The on-vehicle transmitting and receiving device includes one transmitting section, one transmitting antenna connected to the transmitting section, one receiving section, and one receiving antenna connected to the receiving section. Alternatively, the on-vehicle transmitting and receiving device includes one transmitting section, one receiving section, and one transmitting and receiving antenna connected to the transmitting section or to the receiving section in a switching manner. 
     Such conventional keyless entry apparatuses can be divided into two types in terms of their operations. 
     In a first type, on-vehicle transmitting and receiving apparatuses always transmit a request signal intermittently. When a user carrying a portable transmitting and receiving device come close to a vehicle and the portable transmitting and receiving device receives a request signal, the portable transmitting and receiving device transmits an answer signal in response to the request signal. When an on-vehicle transmitting and receiving device receives the answer signal, the locking section of each door of the vehicle is unlocked and the user can open and close each door. 
     In a second type, on-vehicle transmitting and receiving devices have a door-handle-contact detecting sensor near each door handle of vehicles. When a user carrying a portable transmitting and receiving device approaches a vehicle and contacts a door handle, an on-vehicle transmitting and receiving device transmits a request signal. When the portable transmitting and receiving device carried by the user receives the request signal, the portable transmitting and receiving device transmits an answer signal in response to the request signal. When the on-vehicle transmitting and receiving device receives the answer signal, the locking section of each door of the vehicle is unlocked and the user can open and close each door. 
     Therefore, the user can open and close any door without unlocking the locking section of each door of a vehicle by using the door key. 
     The conventional keyless entry apparatuses have an advantage that the user can open and close any door when the user carries a portable transmitting and receiving device and just approaches a vehicle or approaches the vehicle and touches a door handle. Since the locking sections of all the doors of a vehicle are unlocked when the on-vehicle transmitting and receiving device receives an answer signal which the portable transmitting and receiving signal sends in response to a received request signal, a malicious third party can get into the vehicle from a door, such as the door at the seat next to the driver&#39;s seat, at the side opposite the side where the user is located, such as the driver&#39;s side because it is difficult for the user to see the third party. This is not preferred in terms of crime prevention. 
     Especially in the conventional first-type keyless entry apparatuses, when the user approaches a vehicle and is located at a certain distance from the vehicle, for example, at a five-meter distance, even if the user cannot see the vehicle, a request signal and an answer signal are transmitted and received, and the locking section of each door is unlocked. Therefore, it is highly possible that the above-described incident happens. 
     In the conventional keyless entry apparatuses, when the user approaches a vehicle and is located at a certain distance from the vehicle, even if not the locking section of each door of the vehicle but the locking section of a truck is controlled, a request signal and an answer signal are transmitted and received as described above, and the locking section of the trunk is unlocked. Therefore, anybody can open the trunk until the user reaches the trunk, and this is not preferred either in terms of crime prevention. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of the above-described technical background. Accordingly, it is an object of the present invention to provide a keyless entry apparatus for selectively controlling only a member to be controlled located closest to the user when the user approaches a vehicle and a request signal and an answer signal are transmitted and received. 
     Another object of the present invention is to provide a keyless entry apparatus for controlling such that, when the user approaches a vehicle, a request signal and an answer signal are transmitted and received, and the user touches the handle of the door specified by the answer signal, only the door can be selectively opened and closed. 
     One of the foregoing objects of the present invention is achieved in one aspect of the present invention through the provision of a keyless entry apparatus including an on-vehicle transmitting and receiving device mounted on a vehicle; and a portable transmitting and receiving device, wherein the on-vehicle transmitting and receiving device includes a plurality of antennas mounted correspondingly to members to be controlled of the vehicle, and a transmitting section which is connected to the plurality of antennas and which transmits a plurality of request signals having unique antenna IDs; the transmitting section transmits the plurality of request signals through the corresponding antennas; and when the portable transmitting and receiving device receives any of the transmitted request signals, the portable transmitting and receiving device transmits an answer signal which controls the member to be controlled corresponding to the antenna which transmitted the received request signal. 
     According to the keyless entry apparatus, the on-vehicle transmitting and receiving device includes an antenna and a transmitting section for each member to be controlled of a vehicle, a unique ID is assigned to each antenna, the on-vehicle transmitting and receiving device intermittently transmits the same number of request signals having different IDs as that of antennas, and when the portable transmitting and receiving device receives a request signal transmitted from the antenna closest to the portable transmitting and receiving device, the portable transmitting and receiving device transmits an answer signal which specifies the member to be controlled corresponding to the received request signal. When the on-vehicle transmitting and receiving device receives the answer signal, only the member to be controlled specified by the answer signal is controlled, and the other members to be controlled are not controlled. Therefore, the vehicle is effectively prevented from being used by a third party. 
     One of the foregoing objects of the present invention is achieved in another aspect of the present invention through the provision of a keyless entry apparatus including an on-vehicle transmitting and receiving device mounted on a vehicle; and a portable transmitting and receiving device, wherein the on-vehicle transmitting and receiving device includes a plurality of antennas mounted correspondingly to members to be controlled of the vehicle, a transmitting section which is connected to the plurality of antennas and which transmits a plurality of request signals having unique antenna IDs, and a door-handle-contact detecting section disposed at each door of the vehicle; the transmitting section transmits the plurality of request signals through the corresponding antennas; when the portable transmitting and receiving device receives any of the transmitted request signals, the portable transmitting and receiving device transmits an answer signal which controls the member to be controlled corresponding to the antenna which transmitted the received request signal; and when the on-vehicle transmitting and receiving device receives the answer signal, only if the member to be controlled specified by the answer signal is the locking section of any door and the door-handle-contact detecting section of the door corresponding to the answer signal outputs a contact detecting signal, the on-vehicle transmitting and receiving device unlocks the door. 
     According to the keyless entry apparatus, the on-vehicle transmitting and receiving device includes an antenna, each door has a door-handle-contact detecting section, a unique ID is assigned to each antenna, the on-vehicle transmitting and receiving device transmits the same number of request signals having different IDs as that of antennas, and when the portable transmitting and receiving device receives a request signal transmitted from the antenna closest to the portable transmitting and receiving device, the portable transmitting and receiving device transmits an answer signal which specifies the member to be controlled corresponding to the received request signal. When the on-vehicle transmitting and receiving device receives the answer signal, if the member to be controlled specified by the answer signal is the door closest to the portable transmitting and receiving device, and the user touches the handle of the door, only the locking section of the door is unlocked and the locking sections of the other doors are not unlocked. Therefore, the vehicle is completely prevented from being used by a third party. 
     The members to be controlled may include the locking section of each door and the locking section of a trunk in the vehicle. 
     In such a configuration, the locations of the members to be controlled in the vehicle are appropriately apart. Even when an antenna is disposed close to each member to be controlled, ranges in which request signals transmitted from the antennas can reach overlap a little. 
     It is preferred that the plurality of antennas be divided into two groups and the request signals be transmitted at different timing between the groups. 
     In this case, it is be possible that the transmitting section includes a plurality of transmitting units, and at least one of the transmitting units is shared by two antennas. 
     In such a configuration, when the plurality of transmitting units transmit request signals, the interference of the request signals is reduced and the request signals have high quality. When a plurality of transmitting units are shared by two antennas, the number of transmitting units to be used is reduced. 
     It is also preferred that the request signals be low-frequency signals. 
     In such a configuration, a range in which a transmitted request signal can reach is restricted. Therefore, the portable transmitting and receiving device which is relatively apart from the vehicle unpreparedly receives a request signal in reduced cases. The overlapping area of a zone in which a transmitted request signal can reach and a zone in which another transmitted request signal can reach is reduced. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a keyless entry apparatus according to an embodiment of the present invention, and shows an example structure of an on-vehicle transmitting and receiving device. 
     FIG. 2 is a block diagram of the keyless entry apparatus according to the embodiment of the present invention, and shows an example structure of a portable transmitting and receiving device. 
     FIG. 3 is a top view of a vehicle on which the on-vehicle transmitting and receiving device according to the embodiment shown in FIG. 1 is mounted. 
     FIG. 4 is a flowchart of the main operation executed by the on-vehicle transmitting and receiving device according to the present embodiment shown in FIG.  1 . 
     FIG. 5 is a flowchart of the main operation executed by the portable transmitting and receiving device according to the present embodiment shown in FIG.  2 . 
     FIG.  6 A and FIG. 6B are views showing example structures of a request signal and an answer signal transmitted and received between the on-vehicle transmitting and receiving device and the portable transmitting and receiving device. 
     FIG. 7 is a block diagram of a keyless entry apparatus according to a second embodiment of the present invention, and shows an example structure of an on-vehicle transmitting and receiving device. 
     FIG. 8 is a flowchart of an example operation executed by the on-vehicle transmitting and receiving device according to the second embodiment. 
     FIG. 9 is a flowchart of another example operation executed by the on-vehicle transmitting and receiving device according to the second embodiment. 
     FIG. 10 is a block diagram of a keyless entry apparatus according to a third embodiment of the present invention, and shows an example structure of an on-vehicle transmitting and receiving device. 
     FIG. 11 is a block diagram of a keyless entry apparatus according to a fourth embodiment of the present invention, and shows an example structure of an on-vehicle transmitting and receiving device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described below by referring to the drawings. 
     FIG.  1  and FIG. 2 are block diagrams of a keyless entry apparatus according to an embodiment of the present invention. FIG. 1 shows an example structure of an on-vehicle transmitting and receiving device. FIG. 2 shows an example structure of a portable transmitting and receiving device. 
     As shown in FIG. 1, the on-vehicle transmitting and receiving device  10  is formed of a control section (CPU)  1 , a first low-frequency-signal (LF) transmitting section  2 T 1 , a second low-frequency-signal (LF) transmitting section  2 T 2 , a third low-frequency-signal (LF) transmitting section  2 T 3 , a fourth low-frequency-signal (LF) transmitting section  2 T 4 , a fifth low-frequency-signal (LF) transmitting section  2 T 5 , a first transmitting antenna  3 F 1 , a second transmitting antenna  3 F 2 , a third transmitting antenna  3 B, a fourth transmitting antenna  3 R 1 , a fifth transmitting antenna  3 R 2 , a high-frequency-signal (RF) receiving section  4 , a receiving antenna  5 , a storage section  6 , and a locking control section  7 . 
     In this case, as described later, the first transmitting antenna  3 F 1  is disposed on the rear surface of an outside door mirror placed at the side of the driver&#39;s seat, and the second transmitting antenna  3 F 2  is disposed on the rear surface of an outside door mirror placed at the side of the seat next to the driver&#39;s seat. The third transmitting antenna  3 B is disposed in a vicinity of the locking section of the trunk. The fourth transmitting antenna  3 R 1  is disposed in a vicinity of the handle of the door of the rear right seat, and the fifth transmitting antenna  3 R 2  is disposed in a vicinity of the handle of the door of the rear left seat. The receiving antenna  5  is disposed at any place of the vehicle, for example, at the inside ceiling of the vehicle. 
     In this case, the first low-frequency-signal transmitting section  2 T 1  to the fifth low-frequency-signal transmitting section  2 T 5  collectively constitute a transmitting section  2 . 
     The first low-frequency-signal transmitting section  2 T 1  is connected to the control section  1  at the input end, and is connected to the first transmitting antenna  3 F 1  at the output end. The second low-frequency-signal transmitting section  2 T 2  is connected to the control section  1  at the input end, and is connected to the second transmitting antenna  3 F 2  at the output end. The third low-frequency-signal transmitting section  2 T 3  is connected to the control section  1  at the input end, and is connected to the third transmitting antenna  3 B at the output end. The fourth low-frequency-signal transmitting section  2 T 4  is connected to the control section  1  at the input end, and is connected to the fourth transmitting antenna  3 R 1  at the output end. The fifth low-frequency-signal transmitting section  2 T 5  is connected to the control section  1  at the input end, and is connected to the fifth transmitting antenna  3 R 2  at the output end. The high-frequency-signal receiving section  4  is connected to the receiving antenna  5  at the input end, and is connected to the control section  1  at the output end. The storage section  6  is selectively connected to the control section  1 . The locking control section  7  is connected to the control section  1 , and is also connected to a door locking motor  8 F 1  disposed at the side of the driver&#39;s seat, to a door locking motor  8 R 1  disposed at the side of the rear right seat, to a door locking motor  8 F 2  disposed at the side of the seat next to the driver&#39;s seat, to a door locking motor  8 R 2  disposed at the side of the rear left seat, and to a trunk locking motor  8 B. 
     Different IDs (identification symbols) are assigned to the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , the third transmitting antenna  3 B, the fourth transmitting antenna  3 R 1 , and the fifth transmitting antenna  3 R 2 . A request signal transmitted from any of the first to fifth low-frequency-signal transmitting sections  2 T 1  to  2 T 5  includes the ID of the antenna connected to each low-frequency-signal transmitting section. When a portable transmitting and receiving section  20  receives a request signal, the portable transmitting and receiving section  20  can determine the antenna among the first to fifth antenna  3 F 1 ,  3 F 2 ,  3 B,  3 R 1 , and  3 R 2 , through which the request signal was sent, by checking the ID included in the request signal of a received signal. 
     The first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , and the third transmitting antenna  3 B form a first transmitting group, and the fourth transmitting antenna  3 R 1  and the fifth transmitting antenna  3 R 2  form a second transmitting group. The first to third transmitting antennas  3 F 1 ,  3 F 2 , and  3 B, belonging to the first transmitting group, intermittently transmit request signals within a first period by the first to third low-frequency-signal transmitting sections  2 T 1  to  2 T 3  connected thereto. The fourth and fifth transmitting antennas  3 R 1  and  3 R 2 , belonging to the second transmitting group, intermittently transmit request signals within a second period which differs from the first period by the fourth and fifth low-frequency-signal transmitting sections  2 T 4  and  2 T 5  connected thereto. Therefore, the first transmitting group and the second transmitting group do not send intermittent request signals at the same time. 
     The storage section  6  stores the ID assigned to each transmitting antenna, a location code, the ID, described later, of a portable transmitting and receiving device, a function code, and others. 
     As shown in FIG. 2, the portable transmitting and receiving device  20  is formed of a control section (CPU)  11 , a high-frequency-signal (RF) transmitting section  12 , a transmitting antenna  13 , a low-frequency-signal (LF) receiving section  14 , a receiving antenna  15 , a storage section  16 , and an operation key  17 . The transmitting antenna  13  and the receiving antenna  15  are built in the cabinet of the portable transmitting and receiving device  20 , or connected to and disposed together with the cabinet as a unit. 
     The high-frequency-signal transmitting section  12  is connected to the control section  11  at the input end, and is connected to the transmitting antenna  13  at the output end. The low-frequency-signal receiving section  14  is connected to the receiving antenna  15  at the input end, and is connected to the control section  11  at the output end. The storage section  16  is selectively connected to the control section  11 . The operation key is connected to the control section  11 . 
     FIG. 3 is a top view of a vehicle on which the on-vehicle transmitting and receiving device shown in FIG. 1 according to the present embodiment is mounted. 
     In FIG. 3, the same symbols as those used in FIG. 1 are assigned to the same components as those shown in FIG.  1 . 
     As shown in FIG. 3, the vehicle  30  is provided with a door  31 F 1  at the side of the driver&#39;s seat, a door  31 F 2  at the side of the seat next to the driver&#39;s seat, a door  31 R 1  at the side of the rear right seat, a door  31 R 2  at the side of the rear left seat, a trunk  32 , a door mirror  33 M 1  at the side of the driver&#39;s seat, a door mirror  33 M 2  at the side of the seat next to the driver&#39;s seat, a door handle  34 F 1  at the side of the driver&#39;s seat, a door handle  34 F 2  at the side of the seat next to the driver&#39;s seat, a door handle  34 R 1  at the side of the rear right seat, a door handle  34 R 2  at the side of the rear left seat, and the handle  35 N of the trunk  32 . 
     The first transmitting antenna  3 F 1  is mounted and disposed on the rear surface of the door mirror  33 M 1  at the side of the driver&#39;s seat, and the second transmitting antenna  3 F 2  is mounted and disposed on the rear surface of the door mirror  33 M 2  at the side of the seat next to the driver&#39;s seat. The third transmitting antenna  3 B is mounted and disposed in a vicinity of the locking section  35 L of the trunk  32  in line with the locking section  35 L. The fourth transmitting antenna  3 R 1  is mounted and disposed in a vicinity of the handle  34 R 1  of the door for the rear right seat in line with the door handle  34 R 1 , and the fifth transmitting antenna  3 R 2  is mounted and disposed in a vicinity of the handle  34 R 2  of the door for the rear left seat in line with the door handle  34 R 2 . 
     In FIG. 3, semi-circular areas A 1 , A 2 , A 3 , A 4 , and A 5  indicate areas where the portable transmitting and receiving device  20  can receive request signals sent from the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , the third transmitting antenna  3 B, the fourth transmitting antenna  3 R 1 , and the fifth transmitting antenna  3 R 2 , respectively, in a normal condition. 
     FIG. 4 is a flowchart of the main operation executed by the on-vehicle transmitting and receiving device  10  shown in FIG. 1 according to the present embodiment. FIG. 5 is a flowchart of the main operation executed by the portable transmitting and receiving device  20  shown in FIG. 2 according to the present embodiment. 
     FIG.  6 A and FIG. 6B are views showing example structures of a request signal and an answer signal transmitted and received between the on-vehicle transmitting and receiving device  10  and the portable transmitting and receiving device  20 . FIG. 6A shows a request signal transmitted from the on-vehicle transmitting and receiving device  10 , and FIG. 6B shows an answer signal transmitted from the portable transmitting and receiving device  20 . 
     As shown in FIG. 6A, a request signal is formed of a header, an ID assigned to the antenna which transmitted the request signal, a location code which indicates a member to be controlled, and a rolling code updated every time a request signal is transmitted, in that order. As shown in FIG. 6B, an answer signal is formed of a header, an ID assigned to the portable transmitting and receiving device  20  which transmitted the answer signal, a function code which indicates a function input from the operation key  17 , a location code which indicates a member to be controlled, and a rolling code updated every time an answer signal is transmitted, in that order. 
     The operation of the keyless entry apparatus according to the present embodiment will be described below by referring to the flowcharts shown in FIG.  4  and FIG.  5 . 
     In the on-vehicle transmitting and receiving device  10 , at a certain point of time, the first low-frequency-signal transmitting section  2 T 1 , the second low-frequency-signal transmitting section  2 T 2 , and the third low-frequency-signal transmitting section  2 T 3  connected to the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , and the third transmitting antenna  3 B, respectively, all of which belong to the first transmitting group, transmit request signals at the same time for a short period in step S 1  shown in FIG.  4 . In this case, the request signals transmitted from the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , and the third transmitting antenna  3 B are propagated in the areas A 1 , A 2 , and A 3 , respectively. Therefore, they do not interfere with each other. 
     When the low-frequency-signal receiving section  14  of the portable transmitting and receiving device  20  receives any of the request signals, the low-frequency-signal receiving section  14  sends the received signal to the control section  11  in step S 21  shown in FIG.  5 . 
     The control section  11  then determines in step S 22  shown in FIG. 5 whether any of the request signals was received. When it is determined that a request signal was received (Yes in FIG.  5 ), the processing proceeds to step S 23 . When it is determined that a request signal is not received (No in FIG.  5 ), the processing proceeds to step S 27 . 
     In step S 23 , the control section  11  analyzes the ID, the location code, and the rolling code included in the received request signal. 
     Then, the control section  11  determines in step S 24  whether the analyzed ID matches any of IDs stored in the storage section  16 . When the analyzed ID matches one of the stored IDs (Yes in FIG.  5 ), the processing proceeds to step S 25 . When the analyzed ID does not match any of the stored IDs (No in FIG.  5 ), the processing proceeds to step S 27 . In step S 25 , the control section  11  extracts the analyzed location code. 
     Then, in step S 26 , the control section  11  adds the location code corresponding to the extracted location code, to an answer signal to be transmitted. 
     In step S 27 , the control section  11  determines whether a function code has been input from the operation key  17 . When it is determined that a function code has been input (Yes in FIG.  5 ), the processing proceeds to step S 28 . When it is determined that a function code has not been input (No in FIG.  5 ), the processing returns to the first step S 21 , and the subsequent processes are again executed. 
     When it is determined in step S 27  that a function code has been input, the control section  11  transmits a signal including the function code from the high-frequency-signal transmitting section  12  in step S 28 . 
     This signal is neither a request signal nor an answer signal. This signal is sent when a member to be controlled is to be controlled outside the areas where request signals can reach, if the operation key  17  of the portable transmitting and receiving device  20  is operated. The on-vehicle transmitting and receiving device  10  drives the member to be controlled in response to the signal. A description of a method therefor is omitted. 
     The control section  1  of the on-vehicle transmitting and receiving device  10  determines in step S 2  whether the high-frequency-signal receiving section  4  received the answer signal sent in response to the transmitted request signal. When it is determined that the answer signal was received (Yes in FIG.  4 ), the processing proceeds to step S 3 . When it is determined that the answer signal has not been received (No in FIG.  4 ), the processing proceeds to step S 7 . 
     In step S 3 , the control section  1  analyzes the ID, the function code, the location code, and the rolling code included in the received answer signal. 
     Then, in step S 4 , the control section  1  determines whether the analyzed ID matches any of IDs stored in the storage section  6 . When the analyzed ID matches one of the stored IDs (Yes in FIG.  4 ), the processing proceeds to step S 5 . When the analyzed ID does not match any of the stored IDs (No in FIG.  4 ), the processing proceeds to step S 7 . 
     In step S 5 , the control section  1  extracts the analyzed location code. Then, the control section  1  identifies the member to be controlled corresponding to the extracted location code, for example, the door handle  34 F 1  at the side of the driver&#39;s seat, and sends a function code for unlocking the door handle  34 F 1  to the locking control section  7  in step S 6 . The locking control section  7  drives the door locking motor  8 F 1  at the side of the driver&#39;s seat to unlock a locking section  9 F 1  of the door  31 F 1  at the side of the driver&#39;s seat. 
     In the on-vehicle transmitting and receiving device  10 , at a point of time different from the above point of time, the fourth low-frequency-signal transmitting section  2 T 4  and the fifth low-frequency-signal transmitting section  2 T 5  connected to the fourth transmitting antenna  3 R 1  and the fifth transmitting antenna  3 R 2 , respectively, which belong to the second transmitting group, transmit request signals at the same time for a short period in step S 7  shown in FIG.  4 . Also in this case, the request signals transmitted from the fourth low-frequency-signal transmitting section  2 T 4  and the fifth low-frequency-signal transmitting section  2 T 5  are propagated in the areas A 4  and A 5 , respectively. Therefore, they do not interfere with each other. 
     When the low-frequency-signal receiving section  14  of the portable transmitting and receiving device  20  receives any of the request signals, the low-frequency-signal receiving section  14  sends the received signal to the control section  11  in step S 21  shown in FIG.  5 . 
     The portable transmitting and receiving device  20  sequentially executes the processes in step S 22  to step S 28  shown in FIG. 5, and transmits an answer signal from high-frequency-signal transmitting section  12 . 
     In response to the transmission of the answer signal, the control section  1  of the on-vehicle transmitting and receiving device  10  sequentially executes the processes in steps S 8  to S 12  shown in FIG. 4, and analyzes the answer signal. Then, the control section  1  identifies the member to be controlled corresponding to the extracted location code, for example, the door handle  34 R 1  at the side of the rear right seat, and sends a function code for unlocking the door handle  34 R 1  to the locking control section  7  in step S 12 . The locking control section  7  drives the door locking motor  8 R 1  at the side of the rear right seat to unlock a locking section  9 R 1  of the door  31 R 1  at the side of the rear right seat. 
     After the above-described processes have been executed, the processing returns to the first step S 1 , and the subsequent processes are repeated. 
     In the above description, the on-vehicle transmitting and receiving device  10  unlocks the door  31 F 1  at the side of the driver&#39;s seat in response to the answer signal transmitted from the portable transmitting and receiving device  20 , and the on-vehicle transmitting and receiving device  10  unlocks the door  31 R 1  at the side of the rear right seat in response to the answer signal transmitted from the portable transmitting and receiving device  20 . These operations are performed because the portable transmitting and receiving device  20  receives only the request signal transmitted from the first transmitting antenna  3 F 1  in the former case, and the portable transmitting and receiving device  20  receives only the request signal transmitted from the fourth transmitting antenna  3 R 1  in the latter case. When the portable transmitting and receiving device  20  receives only a request signal transmitted from the second transmitting antenna  3 F 2 , the on-vehicle transmitting and receiving device  10  unlocks a locking section  9 F 2  of the door  31 F 2  at the side of the seat next to the driver&#39;s seat in response to the receiving of the answer signal. When the portable transmitting and receiving device  20  receives only a request signal transmitted from the third transmitting antenna  3 B, the on-vehicle transmitting and receiving device  10  unlocks the locking section  35 L of the trunk  32  in response to the receiving of the answer signal. In the same way, when the portable transmitting and receiving device  20  receives only a request signal transmitted from the fifth transmitting antenna  3 R 2 , the on-vehicle transmitting and receiving device  10  unlocks a locking section  9 R 2  of the door  31 R 2  at the side of the rear left seat in response to the receiving of the answer signal. 
     When the portable transmitting and receiving device  20  cannot receive any request signal even if request signals are transmitted from the first to third transmitting antennas  3 F 1 ,  3 F 2 , and  3 B at a certain point of time and other request signals are transmitted from the fourth and fifth antennas  3 R 1  and  3 R 2  at another point of time, the portable transmitting and receiving device  20  does not transmit an answer signal, and any members to be controlled are not controlled. 
     FIG. 7 is a block diagram of a keyless entry apparatus according to a second embodiment of the present invention. FIG. 7 shows an example structure of an on-vehicle transmitting and receiving device  10 . 
     As shown in FIG. 7, the on-vehicle transmitting and receiving device  10  of the keyless entry apparatus according to the second embodiment includes a door-handle sensor  9 F 1  at the side of the driver&#39;s seat, a door-handle sensor  9 F 2  at the side of the seat next to the driver&#39;s seat, a door-handle sensor  9 R 1  at the side of the rear right seat, a door-handle sensor  9 R 2  at the side of the rear left seat, and a trunk-handle sensor  9 B, in addition to all the components included in the on-vehicle transmitting and receiving device  10  shown in FIG.  1 . In FIG. 7, the same symbols as those used in FIG. 1 are assigned to the same components as those shown in FIG.  1 . 
     The door-handle sensor  9 F 1  at the side of the driver&#39;s seat is disposed in the door handle  34 F 1  at the side of the driver&#39;s seat, and is connected to a locking control section  7 . The door-handle sensor  9 F 2  at the side of the seat next to the driver&#39;s seat is disposed in the door handle  34 F 2  at the side of the seat next to the driver&#39;s seat, and is connected to the locking control section  7 . The door-handle sensor  9 R 1  at the side of the rear right seat is disposed in the door handle  34 R 1  at the side of the rear right seat, and is connected to the locking control section  7 . The door-handle sensor  9 R 21  at the side of the rear left seat is disposed in the door handle  34 R 2  at the side of the rear left seat, and is connected to the locking control section  7 . The trunk-handle sensor  9 B is disposed in the trunk handle  35 N, and is connected to a locking control section  7 . 
     In the keyless entry apparatus of the second embodiment, a portable transmitting and receiving device  20  having the same structure as the portable transmitting and receiving device  20  shown in FIG. 2 is used. 
     FIG. 8 is a flowchart of an example operation of the on-vehicle transmitting and receiving device  10  according to the second embodiment. 
     The operation of the keyless entry apparatus having the above-described structure according to the second embodiment will be described next by referring to the flowchart shown in FIG.  8 . 
     The control section  1  of the on-vehicle transmitting and receiving device  10  first detects the states of the members to be controlled corresponding to the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , and the third transmitting antenna  3 B, all of which belong to the first transmitting group, namely, the locking states of the door  31 F 1  at the side of the driver&#39;s seat, the door  31 F 2  at the side of the seat next to the driver&#39;s seat, and the trunk  32 , in step S 31 , and determines in step S 32  whether the door  31 F 1  at the side of the driver&#39;s seat, the door  31 F 2  at the side of the seat next to the driver&#39;s seat, and the trunk  32  are locked. When it is determined that all the doors are locked (Yes in FIG.  8 ), the processing proceeds to step S 33 . When it is determined that at least one of them is not locked (No), the processing proceeds to step S 42 . 
     The control section  1  instructs the first low-frequency-signal transmitting section  2 T 1 , the second low-frequency-signal transmitting section  2 T 2 , and the third low-frequency-signal transmitting section  2 T 3  connected to the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , and the third transmitting antenna  3 B, respectively, all of which belong to the first transmitting group, to transmit request signals, in step S 33 . The request signals are transmitted from the first transmitting antenna  3 F 1 , the second transmitting antenna  3 F 2 , and the third transmitting antenna  3 B. 
     The portable transmitting and receiving device  20  executes the operation illustrated in the flowchart shown in FIG. 5, in response to the transmission of the request signals, and transmits an answer signal. 
     The control section  1  of the on-vehicle transmitting and receiving device  10  extracts a function code, a location code, and others from the received answer signal, in response to the transmission of the answer signal from the portable transmitting and receiving device  20 , in step S 34 . 
     Then, the control section  1  determines in step S 35  whether a location code has been extracted from the answer signal. When it is determined that the location code has been extracted (Yes), the processing proceeds to step S 36 . When it is determined that the location code has not been extracted (No), the processing proceeds to step S 41 . 
     When it is determined in step S 35  that the location code has been extracted, the control section  1  starts a timer to measure a time in step S 36 . The control section  1  then detects a contact detecting signal sent from the sensor disposed in the member to be controlled corresponding to the extracted location code, such as the door-handle sensor  9 F 1  at the side of the driver&#39;s seat, in step S 37 . 
     The control section  1  determines next in step S 38  whether a set time has been over. When it is determined that the set time has been over (Yes), the processing proceeds to step S 42 . When it is determined that the set time has not yet been over (No), the processing proceeds to step S 39 . 
     In step S 39 , the control section  1  determines whether a contact detecting signal detected before the time over was sent from the door-handle sensor  9 F 1  at the side of the driver&#39;s seat. When it is determined that the contact detecting signal was sent from the door-handle sensor  9 F 1  at the side of the driver&#39;s seat (Yes), the processing proceeds to step S 40 . When it is determined that the contact detecting signal was not sent from the door-handle sensor  9 F 1  at the side of the driver&#39;s seat (No), the processing returns to step S 37 , and the subsequent processes are repeated from the step  37 . 
     In step S 40 , since it has been checked that the member to be controlled and the function specified by the answer signal are the door handle  34 F 1  at the side of the driver&#39;s seat and unlocking, respectively, and the contact detecting signal has been output from the door-handle sensor  9 F 1  at the side of the driver&#39;s seat, the control section  1  sends a control signal to the locking control section  7  to drive the door locking motor  8 F 1  at the side of the driver&#39;s seat through the locking control section  7  to unlock the locking section  9 F 1  of the door  31 F 1  at the side of the driver&#39;s seat. 
     In step S 41 , since a location code has not been added to the answer signal, the control section  1  achieves control without specifying a member to be controlled, for example, unlocks at the same time the door handle  34 F 1  at the side of the driver&#39;s seat, the door handle  34 F 2  at the side of the seat next to the driver&#39;s seat, the door handle  34 R 1  at the side of the rear right seat, and the door handle  34 R 2  at the side of the rear left seat. This is a usual keyless entry operation. The processes in steps S 35  to S 41  are performed in response to an operation on the operation key  17  of the portable transmitting and receiving device  20 . 
     The control section  1  outputs instructions to the first to fifth low-frequency-signal transmitting sections  2 T 1  to  2 T 5  to stop transmitting request signals. The processing returns to the first step S 31 , and the subsequent steps are repeated. 
     FIG. 9 is a flowchart of another operation of the on-vehicle transmitting and receiving device  10  according to the second embodiment. In this operation, according to the state of a member to be controlled, the state can be changed to another state. 
     The operation illustrated in FIG. 9 is the same as the operation shown in the flowchart of FIG. 8, except that, when the locking state of a member to be controlled, such as the door handle  34 F 1  at the side of the driver&#39;s seat, was not detected in step S 32 , the processing does not directly proceed to step S 42  but proceeds to step S 42  through steps S 43  to S 45 . In FIG. 9, the same symbols as those used in FIG. 8 are assigned to the steps having the same functions as those illustrated in the flowchart shown in FIG.  8 . 
     In the following description, only the operation related to steps S 43  to S 45  will be explained. Since steps S 31  to S 42  have been described, a description therefor will be omitted. 
     Since the locking state of the door handle  34 F 1  at the side of the driver&#39;s seat was not detected, namely, the door handle is not locked, the control section  1  outputs instructions to the first and second low-frequency-signal transmitting sections  2 T 1  and  2 T 2  in step S 43  to transmit request signals so that the door handle  34 F 1  at the side of the driver&#39;s seat and the door handle  34 F 2  at the side of the seat next to the driver&#39;s seat are locked. 
     In response to the transmission of the request signals, the portable transmitting and receiving device  20  transmits an answer signal. The control section  1  determines in step S 44  whether the answer signal has been received. When it is determined that the answer signal has not yet been determined (No), the processing proceeds to step S 45 . When it is determined that the answer signal has been received (Yes), step S 44  is repeated. 
     The control section  1  sends a control signal to the locking control section  7  in step S 45  to drive the door locking motor  8 F 1  at the side of the driver&#39;s seat through the locking control section  7  to lock the door  31 F 1  at the side of the driver&#39;s seat. The processing then proceeds to step S 42 . The processes achieved in steps S 43  to S 45  are used to automatically lock the door when the user who carries the portable transmitting and receiving device  20  leaves the vehicle. 
     FIG. 10 is a block diagram of a keyless entry apparatus according to a third embodiment of the present invention. FIG. 10 shows an example structure of an on-vehicle transmitting and receiving device  10 . The structure of a transmitting section is changed from those shown in FIG.  1  and FIG.  2 . 
     As shown in FIG. 10, the on-vehicle transmitting and receiving device  10  of the third embodiment uses three low-frequency-signal transmitting sections, a first low-frequency-signal transmitting section  2 T 1 ′, a second low-frequency-signal transmitting section  2 T 2 ′, and a third low-frequency-signal transmitting section  2 T 3 ′, for a first transmitting antenna  3 F 1 , a second transmitting antenna  3 F 2 , a third transmitting antenna  3 B, a fourth transmitting antenna  3 R 1 , and a fifth transmitting antenna  3 R 2 . In addition, a control section  1  is provided with an antenna switching section  1 S, and two switches, a first switch  1 S 1  and a second switch  1 S 2 , are employed. In FIG. 10, the same symbols as those used in FIG. 1 are assigned to the same components as those shown in FIG.  1 . 
     The first low-frequency-signal transmitting section  2 T 1 ′ is connected to a control section  1  at the input end and is connected to the first transmitting antenna  3 F 1  at the output end. The input end of the second low-frequency-signal transmitting section  2 T 2 ′ is connected to the control section  1  and the output end thereof is connected to the input end of the first switch  1 S 1 . The input end of the third low-frequency-signal transmitting section  2 T 3 ′ is connected to the control section  1  and the output end thereof is connected to the input end of the second switch  1 S 2 . The first switch  1 S 1  is connected to the second transmitting antenna  3 F 2  at a first output end, is connected to the fourth transmitting antenna  3 R 1  at a second output end, and is connected to the antenna switching section  1 S at a control end. The second switch  1 S 2  is connected to the third transmitting antenna  3 B at a first output end, is connected to the fifth transmitting antenna  3 R 2  at a second output end, and is connected to the antenna switching section  1 S at a control end. 
     The on-vehicle transmitting and receiving section  10  having the above structure according to the third embodiment operates in the following way. 
     When the low-frequency-signal transmitting sections transmit request signals through the transmitting antennas belonging to a first transmitting group, the control section  1  connects the input end of the first switch  1 S 1  to its first output end and connects the input end of the second switch  1 S 2  to its first output end so as to connect the second low-frequency-signal transmitting section  2 T 2 ′ to the second transmitting antenna  3 F 2  and to connect the third low-frequency-signal transmitting section  2 T 3 ′ to the third transmitting antenna  3 B, by using the antenna switching section  1 S. In this case, when the control section  1  instructs the first low-frequency-signal transmitting section  2 T 1 ′, the second low-frequency-signal transmitting section  2 T 2 ′, and the third low-frequency-signal transmitting section  2 T 3 ′ to transmit request signals, the first low-frequency-signal transmitting section  2 T 1 ′ directly sends a request signal to the first transmitting antenna  3 F 1 , the second low-frequency-signal transmitting section  2 T 2 ′ sends a request signal to the second transmitting antenna  3 F 2  through the first switch  1 S 1 , and the third low-frequency-signal transmitting section  2 T 3 ′ sends a request signal to the third transmitting antenna  3 B through the second switch  1 S 2 . The request signals are transmitted from the antennas  3 F 1 ,  3 F 2 , and  3 B. 
     When the low-frequency-signal transmitting sections transmit request signals through the transmitting antennas belonging to a second transmitting group, the control section  1  connects the input end of the first switch  1 S 1  to its second output end and connects the input end of the second switch  1 S 2  to its second output end so as to connect the second low-frequency-signal transmitting section  2 T 2 ′ to the fourth transmitting antenna  3 R 1  and to connect the third low-frequency-signal transmitting section  2 T 3 ′ to the fifth transmitting antenna  3 R 2 , by using the antenna switching section  1 S. In this case, when the control section  1  instructs the second low-frequency-signal transmitting section  2 T 2 ′ and the third low-frequency-signal transmitting section  2 T 3 ′ to transmit request signals, the second low-frequency-signal transmitting section  2 T 2 ′ sends a request signal to the fourth transmitting antenna  3 R 1  through the first switch  1 S 1 , and the third low-frequency-signal transmitting section  2 T 3 ′ sends a request signal to the fifth transmitting antenna  3 R 2  through the second switch  1 S 2 . The request signals are transmitted from the antennas  3 R 1  and  3 R 2 . 
     Since the operation of the on-vehicle transmitting and receiving device  10  according to the third embodiment is the same as that of the on-vehicle transmitting and receiving device  10  of the first embodiment or the second embodiment, described above, except for the transmission of request signals from the first to third low-frequency-signal transmitting sections  2 T 1 ′ to  2 T 3 ′, a more detailed description will be omitted. 
     FIG. 11 is a block diagram of a keyless entry apparatus according to a fourth embodiment of the present invention. FIG. 11 shows another example structure of an on-vehicle transmitting and receiving device  10 . The structure of a transmitting section is changed from that shown in FIG.  1 . 
     As shown in FIG. 11, in the on-vehicle transmitting and receiving device  10  of the fourth embodiment, a first transmitting antenna  3 F 1 , a second transmitting antenna  3 F 2 , a third transmitting antenna  3 B, a fourth transmitting antenna  3 R 1 , and a fifth transmitting antenna  3 R 2  are connected to one transmitting section  2 ′ through a switch  1 S 1 ′ for switching a transmitting antenna. The transmitting section  2 ′ is connected to a control section  1 . The switch  1 S 1 ′ is connected to an antenna switching section  1 S′ of the control section  1 , and switches a transmitting antenna according to an instruction sent from the antenna switching section  1 S′. 
     The on-vehicle transmitting and receiving device  10  having the above structure according to the fourth embodiment operates in the following way. 
     The control section  1  sequentially reads and combines IDs and location codes stored in the storage section  6  to generate a request signal to be transmitted from the first transmitting antenna  3 F 1 , a request signal to be transmitted from the second transmitting antenna  3 F 2 , a request signal to be transmitted from the third transmitting antenna  3 B, a request signal to be transmitted from the fourth transmitting antenna  3 R 1 , and a request signal to be transmitted from the fifth transmitting antenna  3 R 2 , and sequentially sends them to the transmitting section  2 ′ at certain time intervals. The transmitting section  2 ′ converts the request signals to low-frequency signals and sequentially sends them to the transmitting antennas through the switch  1 S 1 ′. The transmitting section  2 ′ sends the low-frequency signals at the same time intervals as the control section  1  sends the request signals to the transmitting section  2 ′. The antenna switching section  1 S′ in the control section  1  instructs the switch  1 S 1 ′ to switch a transmitting antenna, according to the transmitting timing of the request signals from the transmitting section  2 ′. 
     Therefore, the request signal to be transmitted from the first transmitting antenna  3 F 1  is transmitted from the first transmitting antenna  3 F 1 , and the other request signals are also always transmitted from the corresponding transmitting antennas. As for the certain time intervals, for example, the request signal to be transmitted from the first transmitting antenna  3 F 1  the request signal to be transmitted from the second transmitting antenna  3 F 2 , and the request signal to be transmitted from the third transmitting antenna  3 B are continuously transmitted at an interval of 20 ms, a period of 200 ms elapses, and then, the request signal to be transmitted from the fourth transmitting antenna  3 R 1  and the request signal to be transmitted from the fifth transmitting antenna  3 R 2  are continuously transmitted at an interval of 20 ms. 
     In the first embodiment, a request signal to be transmitted from the first transmitting antenna  3 F 1 , a request signal to be transmitted from the second transmitting antenna  3 F 2 , and a request signal to be transmitted from the third transmitting antenna  3 B, in other words, request signals to be transmitted from the first-group transmitting antennas, are transmitted at the same time, and a request signal to be transmitted from the fourth transmitting antenna  3 R 1  and a request signal to be transmitted from the fifth transmitting antenna  3 R 2 , in other words, request signals to be transmitted from the second-group transmitting antennas, are transmitted at the same time. In contrast, in the present embodiment, request signals are not transmitted at the same time, but continuously transmitted. Both embodiments have the same structure in which transmitting antennas are divided into two groups. 
     In the fourth embodiment, the operation of the portable transmitting and receiving device  20 , and the operation of the on-vehicle transmitting and receiving device  10  achieved after an answer signal is received from the portable transmitting and receiving device  20  are the same as in the first embodiment. Therefore, a description thereof will be omitted. 
     As described above, according to the present invention, an on-vehicle transmitting and receiving device includes an antenna and a transmitting section for each member to be controlled of a vehicle, a unique ID is assigned to each transmitting section, the on-vehicle transmitting and receiving device intermittently transmits the same number of request signals having different IDs as that of transmitting sections, and when a portable transmitting and receiving device receives a request signal transmitted from the antenna closest to the portable transmitting and receiving device, the portable transmitting and receiving device transmits an answer signal which specifies the member to be controlled corresponding to the received request signal. When the on-vehicle transmitting and receiving device receives the answer signal, only the member to be controlled specified by the answer signal, that is, the member to be controlled disposed closest to the portable transmitting and receiving device, is controlled, and other members to be controlled are not controlled. Therefore, the present invention provides an advantage that the vehicle is effectively prevented from being used by a third party. 
     In addition, according to the present invention, an on-vehicle transmitting and receiving device includes an antenna and a transmitting section for each member to be controlled of a vehicle, each door has a door-handle-contact detecting section, a unique ID is assigned to each transmitting section, the on-vehicle transmitting and receiving device transmits the same number of request signals having different IDs as that of transmitting sections, and when a portable transmitting and receiving device receives a request signal transmitted from the antenna closest to the portable transmitting and receiving device, the portable transmitting and receiving device transmits an answer signal which specifies the member to be controlled corresponding to the received request signal. When the on-vehicle transmitting and receiving device receives the answer signal, if the member to be controlled specified by the answer signal is the door closest to the portable transmitting and receiving device, and the user touches the handle of the door, only the locking section of the door is unlocked and the locking sections of the other doors are not unlocked. Therefore, the present invention provides an advantage that the vehicle is completely prevented from being used by a third party.