JP5684983B2 - Communication area forming device for electronic key system - Google Patents

Description

  The present invention relates to a communication area forming apparatus of an electronic key system that forms a communication area for an ID reply request from a communication master and executes ID collation using an ID code returned by an electronic key in response to the ID reply request.

  2. Description of the Related Art Conventionally, an electronic key system that performs ID collation by transmitting an ID code wirelessly from an electronic key as a vehicle key has been widely used. This electronic key system includes a key operation smart system that transmits a request as an ID code return request from a vehicle and performs ID collation using an ID code returned from the electronic key in response to the request. The key operation-free system includes a smart entry system in which door lock locking / unlocking is permitted or executed when ID verification is established outside the vehicle, and when the ID verification is established in the vehicle, the engine can be started simply by pressing the engine switch inside the vehicle. There is a one-push engine start system.

  In one type of this electronic key system, as shown in FIG. 9, an antenna 83 is arranged on the driver's seat door 81 side (vehicle body right side) of the vehicle 80, and an antenna 84 is installed on the passenger seat door 82 side (vehicle body left side). A technique (Patent Documents 1, 2, etc.) for determining the key position by logical determination of the response returned from the electronic key 85 to the radio waves transmitted from the antennas 83 and 84 has been devised. In this logical determination key position detection method, a request is transmitted in order from the driver's seat antenna 83 installed on the right side of the vehicle body and the passenger's seat antenna 84 installed on the left side of the vehicle body, and the driver's seat antenna area 86 and the passenger seat antenna area are transmitted. 87 are formed in order, and the key position is determined by the ID code returned by the electronic key 85 in response to these requests, that is, the logical determination of the response.

  For example, if there is a response from the electronic key 85 to the request for the driver's seat antenna 83 and there is no response from the electronic key 85 to the request for the passenger seat antenna 84, it is determined that the electronic key 85 is located outside the vehicle. If there is no response from the electronic key 85 to the request from the driver's seat antenna 83 and there is a response from the electronic key 85 to the request from the passenger seat antenna 84, it is determined that the electronic key 85 is located outside the vehicle. Furthermore, if there is a response to both the request for the driver's seat antenna 83 and the request for the passenger's seat antenna 84, it is determined that the electronic key 85 is located in the vehicle.

  In the logical determination key position detection method shown in FIG. 9, the positions of both the outside and the inside of the vehicle can be seen with a pair of antennas provided on the right side and the left side of the vehicle. Therefore, the logical determination key position detection method is, for example, compared with the case where an antenna is installed at each door as an antenna outside the vehicle and a plurality of antennas are installed inside the vehicle as antennas inside the vehicle to detect the position of the electronic key. There is an advantage that the number of antennas can be reduced to the extent that it only needs to be installed on the left and right sides of the vehicle body.

JP 2004-84406 A JP 2005-76329 A

  However, in the logic determination key position detection method, there is a demand for reducing the number of antennas because antennas must be arranged on the driver's seat side and the passenger seat side, respectively. Further, for example, as shown in FIG. 10, when the electronic key 2 is positioned at the corner position 88 on the driver's seat side in the vehicle, only the driver's seat antenna area 86 can reach the corner position 88. Therefore, since the position determination result does not react to both antennas 83 and 84, a null point cannot be determined as being in the vehicle even though the electronic key 2 is in the vehicle. For this reason, there has been a problem that the position of the electronic key 2 is erroneously determined.

  An object of the present invention is to provide a communication area forming apparatus of an electronic key system that can reduce the number of antennas of a communication master and can also ensure the position detection accuracy of the electronic key.

In order to solve the above problem, in the present invention, in the communication area forming apparatus of the electronic key system that performs ID collation by the ID code returned from the electronic key in response to the ID reply request from the communication master, the communication master And a multi-axis integrated antenna provided with at least two antenna members arranged in different axial directions, and individually transmitting radio waves from each of the plurality of antenna members, and the antenna member A transmission execution means for forming a communication area having different directivity by simultaneously transmitting radio waves from a plurality of the electronic keys and executing the ID collation with the electronic key, wherein the transmission execution means includes the communication area. When a plurality of passwords are formed and ID verification is performed with the electronic key, subsequent communication is performed at the time when confirmation of the ID verification is established. Stop rear formation, the transmission execution means, the selectively formed outside communication area and the indoor communication area as the communication area, whether the ID verification is to establish in which of the outdoor communication area or the indoor communication area By checking, it is possible to determine whether the electronic key is located outdoors or indoors. When it is detected that the lock button provided outside the room is operated, the electronic key in the room is first detected. The gist is to execute ID verification with the electronic key outside the room, and then execute ID verification with the electronic key outside the room .

According to this configuration, by communicating each axis of the multi-axis integrated antenna individually or simultaneously, various communication areas are formed in the communication master, and communication with the electronic key is executed. For this reason, even if it takes the form which forms various communication areas in a communication master and performs ID collation with an electronic key, since the antenna installed in a communication master only needs one of the multi-axis integrated antennas, It is possible to reduce the number of antennas on the communication master side. In addition, communication areas having different directivities are formed when each axis of the multi-axis integrated antenna is individually transmitted and when these axes are simultaneously transmitted. For this reason, for example, a location that becomes a null point in the communication area at the time of single transmission can be complemented by the communication area at the time of simultaneous transmission, so that it is possible to ensure communication establishment. Moreover, since it is not necessary to form a useless communication area, it is possible to save the power of the communication master.
According to this configuration, the outdoor communication area and the indoor communication area are formed as the communication area, and the position of the electronic key is determined indoors and outdoors. Therefore, it is more accurately determined whether the electronic key is located outdoors or indoors. It becomes possible to do.

  In the present invention, when transmitting the plurality of antenna members at the same time, the transmission execution means causes the antenna members to transmit simultaneously in the same phase and simultaneously transmits the antenna members in the opposite phase so that the directivities are orthogonal to each other. The gist is to form a communication area.

  According to this configuration, since simultaneous transmission is executed in the same phase and opposite phase, it is possible to form communication areas having different directivities even in simultaneous transmission. Therefore, since it is possible to give diversity to the shape of the communication area, it is possible to further ensure communication establishment.

  The gist of the present invention is that it comprises communication area changing means for changing the size of the communication antenna by changing the transmission intensity of the antenna member when the antenna member forms the communication area.

  According to this configuration, by changing the transmission strength of the two-axis integrated antenna, it is possible to change the size and form the communication area. For example, compared with a case where all the communication areas are formed with a constant transmission strength. Thus, it is possible to form a communication area within a suitable range. Therefore, since a suitable communication area corresponding to the component arrangement and shape of the communication master is formed, it is possible to further ensure communication feasibility.

  According to the present invention, the number of antennas of the communication master can be reduced, and the position detection accuracy of the electronic key can be ensured.

The lineblock diagram showing the schematic structure of the communication area formation device in a 1st embodiment. The block diagram which shows the components structure of a biaxial integrated antenna. The conceptual diagram which shows the electromagnetic wave image which a 2 axis | shaft integrated antenna radiates | emits. The conceptual diagram which shows the state which the electronic key located in the communication area outside a vehicle. (A) is a conceptual diagram which shows the state in which the electronic key was located in the communication area outside a vehicle, (b) is a conceptual diagram which shows the state in which the electronic key was located in the communication area in a vehicle. The block diagram which shows schematic structure of the communication area formation apparatus in 2nd Embodiment. The conceptual diagram which shows the state which the electronic key located in the communication area outside a vehicle. (A) is a conceptual diagram when the electronic key is outside the vehicle, (b) is a conceptual diagram when the electronic key is inside the vehicle. The schematic diagram which shows schematic structure of the conventional electronic key system. The conceptual diagram which shows the state in which the electronic key was located in the null point in a vehicle.

(First embodiment)
Hereinafter, a first embodiment of a communication area forming apparatus for an electronic key system embodying the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the vehicle 1 has a key operation free system 3 that automatically performs ID (Identification) verification when the electronic key 2 approaches the vehicle 1 as a kind of electronic key system that performs key verification wirelessly. Is provided. This key operation free system 3 includes a smart entry system in which a door lock is unlocked and unlocked in a series of door opening and closing operations without actually performing a key operation, and a push type engine installed in the vehicle. There is a one-push engine start system that can start the engine only by pressing the switch 4. The vehicle 1 corresponds to a communication master, and the key operation free system 3 corresponds to an electronic key system.

  In this case, the vehicle 1 includes a key verification device 5 that performs ID verification with the electronic key 2, a door lock device 6 that manages a door lock operation, and an engine start device 7 that manages the operation of the engine. These are provided and connected by an in-vehicle bus 8. The key verification device 5 is provided with a verification ECU (Electronic Control Unit) 9 as a control unit of the device 5. In the memory (not shown) of the verification ECU 9, the ID code of the electronic key 2 that forms a pair with the vehicle 1 is registered. Connected to the verification ECU 9 are a vehicle transmitter 10 that transmits radio waves in the LF (Low Frequency) band around and in the vehicle, and a vehicle tuner 11 that receives radio waves in the UHF (Ultra High Frequency) band. One vehicle transmitter 10 is provided at the center position in the vehicle width direction of the vehicle 1 and intermittently transmits a request signal Srq by an LF band radio wave as an ID reply request to the electronic key 2. The vehicle transmitter 10 corresponds to a multi-axis integrated antenna.

  The electronic key 2 is provided with a communication control unit 12 that performs overall control of the operation of the electronic key 2. An ID code is registered in the memory (not shown) of the communication control unit 12 as an ID unique to the key. The communication control unit 12 is connected to an LF receiver 13 capable of receiving LF band radio waves and a UHF transmitter 14 capable of transmitting UHF band radio waves. When the electronic key 2 receives the request signal Srq by the LF receiver 13, the electronic signal 2 transmits the ID signal Sid including the ID code by the UHF transmitter 14 using radio waves in the UHF band.

  When the electronic key 2 is located outside the vehicle, the request signal Srq is intermittently transmitted from the vehicle transmitter 10. At this time, when the electronic key 2 receives the request signal Srq, in response to the request signal Srq, the electronic signal 2 returns an ID signal Sid by radio waves in the UHF band. The ID signal Sid includes the ID code of the electronic key 2. When the vehicle tuner 11 receives the ID signal Sid and establishes smart communication outside the vehicle (external communication), the verification ECU 9 executes external verification as ID verification (smart verification). And if this outside vehicle collation is materialized, door lock locking / unlocking by the door lock device 6 is permitted or executed.

  Further, when it is detected by a courtesy switch or the like that the driver has boarded, transmission of the request signal Srq from the vehicle transmitter 10 is also started at this time. At this time, when the electronic key 2 receives the request signal Srq of the vehicle transmitter 10 to establish in-vehicle smart communication (in-vehicle communication), the verification ECU 9 executes in-vehicle verification as ID verification (smart). And if this in-vehicle collation is materialized, the power supply transition operation and engine starting operation by the engine switch 4 (engine starting device 7) will be permitted.

  As shown in FIGS. 1 to 3, in the key operation free system 3 of this example, a two-axis integrated antenna is used as the vehicle transmitter 10, and each axis of the antenna is individually transmitted or simultaneously transmitted. There is provided a communication area forming device 15 that forms communication areas with different directivities and establishes smart collation. As shown in FIG. 2, the biaxial integrated antenna refers to an antenna including a pair of coil bar antennas 16a and 16b in which the coil axes L1 and L2 are arranged in a direction orthogonal to each other. The communication area forming apparatus 15 forms communication areas in different directions by individually transmitting or simultaneously transmitting radio waves from the antennas 16a and 16b, and executes external verification and in-vehicle verification. The coil bar antennas 16a and 16b constitute an antenna member, and the coil axes L1 and L2 correspond to the axes.

  As shown in FIGS. 2 and 3, the vehicle transmitter 10 is provided with a substrate 17 as a mounting destination of electronic components of the vehicle transmitter 10, and a pair of coil bar antennas 16 a and 16 b are mounted on the substrate 17. ing. The vehicle transmitter 10 includes a first coil bar antenna 16a in which the coil axis L1 is oriented along the vehicle width direction, and a second coil bar antenna 16b in which the coil axis L2 is oriented along the vehicle longitudinal direction. The coil bar antennas 16a and 16b are antennas in which a plurality of antenna elements are wound around a magnetic material such as ferrite. The coil bar antennas 16a and 16b are arranged side by side on the same plane, and are arranged so that the coil axes L1 and L2 are orthogonal to each other. The coil axis L1 (L2) is a line in the direction in which the coils of the coil bar antenna 16a (16b) are arranged, that is, a line along a magnetic field passing through the inside of the coil, and corresponds to the antenna axis.

  The communication areas (magnetic field areas) of these coil bar antennas 16a and 16b are formed such that the magnetic field in the antenna axial direction (longitudinal direction) is larger than the magnetic field in the perpendicular direction. Actually, the magnetic field in the direction of the antenna axis is formed with a size about twice that in the direction orthogonal to the antenna axis. Therefore, as shown in FIG. 3, these coil bar antennas 16a and 16b form an elliptical communication area, and as a result, directivity is formed facing the antenna axial direction.

  By the way, as shown in FIG. 3, the first communication area E1 formed when the first coil bar antenna 16a is transmitted alone and the second communication area E1 formed when the second coil bar antenna 16b is transmitted alone. The communication area E2 is formed so that the directivities are orthogonal to each other. This is because the coil bar antennas 16a and 16b are arranged with their antenna axes orthogonal to each other.

  Further, the third communication area E3 formed when the first coil bar antenna 16a and the second coil bar antenna 16b are simultaneously transmitted in the same phase is relative to the first communication area E1 (second communication area E2). , The phase is inclined by 45 degrees, that is, the directivity is formed in a direction different by 45 degrees. On the other hand, the fourth communication area E4 formed when the first coil bar antenna 16a and the second coil bar antenna 16b are simultaneously transmitted in opposite phases is the third communication area E3 that is formed when simultaneous transmission is performed in the same phase. On the other hand, the phase is inclined by 90 degrees, that is, the directivity is formed in a direction different by 90 degrees.

  By the way, in the first communication area E1 to the fourth communication area E4, it can be seen that there is a correlation included in the area in the other communication area even when the area is outside the area. Therefore, if the first communication area E1 to the fourth communication area E4 are properly used, locations that are outside the area when viewed in one communication area can be complemented by other communication areas. For this reason, the communication area formation apparatus 15 of this example uses the 1st communication area E1-the 4th communication area E4 properly by vehicle collation and vehicle collation, and uses the vehicle exterior communication area (outdoor communication area) and vehicle interior communication area (room interior). Communication area).

  In the case of this example, since the first coil bar antenna 16a is arranged in the vehicle width direction and the second coil bar antenna 16b is arranged in the vehicle front-rear direction, the first communication area E1 has an elliptical shape that is long in the vehicle width direction. The second communication area E2 is formed of an elliptical area that is long in the vehicle front-rear direction. Here, the first communication area E1 formed in the vehicle width direction is used as the vehicle outside communication area. Further, the third communication area E3 and the fourth communication area are formed in an area in which the directivity is inclined by 45 degrees with respect to the first communication area E1 or the second communication area E2, that is, in an area along the diagonal line of the vehicle body. Here, the communication areas E2 to E4 are used as in-vehicle communication areas.

  The verification ECU 9 is provided with an out-of-vehicle communication area forming unit 18 that forms an out-of-vehicle communication area around the vehicle at the time of out-of-vehicle verification. The outside communication area forming unit 18 first transmits the first coil bar antenna 16a alone to form the first communication area E1 around the vehicle, and then simultaneously transmits the two coil bar antennas 16a and 16b in the same phase. The third communication area E3 is formed around the vehicle, and finally the two coil bar antennas 16a and 16b are simultaneously transmitted in opposite phases to form the fourth communication area E4 around the vehicle. Thus, a large area extending over the three areas of the first communication area E1, the third communication area E3, and the fourth communication area E4 is formed around the vehicle as an outside communication area, and the electronic key 2 is placed in the outside communication area. When located, outside vehicle verification is performed. In addition, the vehicle exterior communication area formation part 18 comprises a transmission execution means.

  The verification ECU 9 is provided with an in-vehicle communication area forming unit 19 that forms an in-vehicle communication area in the vehicle 1 at the time of in-vehicle verification. The in-vehicle communication area forming unit 19 transmits only the second coil bar antenna 16b out of the two coil bar antennas 16a and 16b, and forms the second communication area E2 in the vehicle. Thereby, in the vehicle, the second communication area E2 is formed as the vehicle interior area. When the electronic key 2 is located in the vehicle communication area, the vehicle interior verification is executed. The in-vehicle communication area forming unit 19 constitutes a transmission execution unit.

  As shown in FIG. 4, the first coil bar antenna 16 a is provided with a coil 20, a capacitor 21, and a first antenna drive circuit 22. The coil 20 and the capacitor 21 are formed as a series resonance circuit of the first coil bar antenna 16 a and are driven by the first antenna drive circuit 22. The second coil bar antenna 16b is provided with a coil 23, a capacitor 24, and a second antenna drive circuit 25. The coil 23 and the capacitor 24 are formed as a series resonance circuit of the second coil bar antenna 16 b and are driven by the second antenna drive circuit 25.

  The verification ECU 9 is provided with a transmission waveform generation circuit 26 that generates and outputs transmission data D to the vehicle transmitter 10. The transmission waveform generation circuit 26 is connected to the first coil bar antenna 16a via the first switch 27, and is connected to the second coil bar antenna 16b via the inverting circuit 28 and the second switch 29. The inverting circuit 28 is provided with an inverter 30 for inverting the phase of an input signal and outputting it, and a third switch 31 composed of one circuit and two contact switches. The third switch 31 is a switch that determines whether the second coil bar antenna 16 b is connected directly to the transmission waveform generation circuit 26 or is connected via the inverter 30.

  When the first coil bar antenna 16a is transmitted alone, the first switch 27 is turned on, the second switch 29 is turned off, and the third switch 31 is connected to the a contact 31a. Thereby, the transmission data D from the transmission waveform generation circuit 26 flows only to the first coil bar antenna 16a, and radio waves are transmitted only from the first coil bar antenna 16a. When the second coil bar antenna 16b is transmitted alone, the first switch 27 is turned off, the second switch 29 is turned on, and the third switch 31 is connected to the a contact 31a. Thereby, the transmission data D from the transmission waveform generation circuit 26 flows only to the second coil bar antenna 16b, and radio waves are transmitted only from the second coil bar antenna 16b.

  When radio waves are simultaneously transmitted from the first coil bar antenna 16a and the second coil bar antenna 16b in the same phase, both the first switch 27 and the second switch 29 are turned on, and the third switch 31 is connected to the a contact 31a. The As a result, the transmission data D from the transmission waveform generation circuit 26 flows in the same phase in both the first coil bar antenna 16a and the second coil bar antenna 16b, and radio waves are simultaneously transmitted in the same phase from these coil bar antennas 16a and 16b. .

  When simultaneously transmitting radio waves from the first coil bar antenna 16a and the second coil bar antenna 16b in opposite phases, both the first switch 27 and the second switch 29 are turned on, and the third switch 31 is connected to the b contact 31b. Is done. Therefore, the second coil bar antenna 16 b is connected to the transmission waveform generation circuit 26 via the inverter 30. For this reason, the transmission data D of the transmission waveform generation circuit 26 flows into the first coil bar antenna 16a as it is, but flows into the second coil bar antenna 16b in a phase-inverted state. Accordingly, radio waves are simultaneously transmitted in opposite phases from the first coil bar antenna 16a and the second coil bar antenna 16b.

Next, the operation of the communication area forming apparatus 15 of this example will be described with reference to FIG.
When the vehicle 1 is parked, the outside communication area forming unit 18 intermittently forms the outside communication area as shown in FIG. 5A in order to confirm the presence or absence of the electronic key 2 approaching the vehicle 1. . At this time, the vehicle exterior communication area forming unit 18 transmits the request signal Srq alone only from the first coil bar antenna 16a, and subsequently simultaneously transmits the request signal Srq from the two coil bar antennas 16a and 16b in the same phase. Request signals Srq are simultaneously transmitted in opposite phases from the two coil bar antennas 16a and 16b, and this series of transmission operations is repeatedly executed at predetermined intervals. Thereby, the 1st communication area E1, the 3rd communication area E3, and the 4th communication area E4 are formed in order around the vehicle, and the communication area outside a vehicle is formed over a wide range.

  When the electronic key 2 enters one of the first communication area E1, the third communication area E3, and the fourth communication area E4, the electronic key 2 receives the request signal Srq and returns the ID signal Sid to the vehicle 1. When the vehicle tuner 11 receives the ID signal Sid under vehicle communication, the verification ECU 9 recognizes that the vehicle communication has been established, and executes ID verification, that is, vehicle verification using the ID code of the received ID signal Sid. When the verification ECU 9 confirms that the verification outside the vehicle is established, the verification ECU 9 stops the subsequent communication area formation and permits the unlocking operation by the door lock device 6. Therefore, when the outside door handle knob is touch-operated, the door lock is unlocked.

  When detecting that the driver has boarded, for example, with a courtesy switch or the like, the in-vehicle communication area forming unit 19 checks the presence / absence of the electronic key 2 in the vehicle, and this time, as shown in FIG. Is formed intermittently. At this time, the in-vehicle communication area forming unit 19 transmits the request signal Srq solely from only the second coil bar antenna 16b, and repeatedly performs this transmission operation at predetermined intervals. Thus, the third communication area E3 is intermittently formed in the vehicle, and the in-vehicle communication area is formed over the entire interior of the vehicle.

  When the electronic key 2 enters the second communication area E2, the electronic key 2 receives the request signal Srq and returns an ID signal Sid to the vehicle 1. When the ID signal Sid is received by the vehicle tuner 11 under in-vehicle communication, the verification ECU 9 recognizes that in-vehicle communication has been established, and executes ID verification, that is, in-vehicle verification, using the ID code of the received ID signal Sid. When the verification ECU 9 confirms that the in-vehicle verification is established, the verification ECU 9 permits the engine start operation and the power supply transition operation by the engine switch 4.

  When the driver gets off after driving and the lock button on the outside door handle knob is pressed, an operation is performed to check whether or not the outside verification is established. Then, check whether the electronic key 2 is left behind in the car. At this time, the in-vehicle communication area forming unit 19 forms the in-vehicle communication area by transmitting only the second coil bar antenna 16b alone, and recognizes that the electronic key 2 has not been left in the vehicle if the in-vehicle verification is not established. .

  If it can be confirmed that the electronic key 2 is not misplaced in the vehicle, this time, the process proceeds to outside-vehicle verification. At this time, the vehicle exterior communication area forming unit 18 forms the first communication area E1, the third communication area E3, and the fourth communication area E4 in order in the same manner as when the door lock is unlocked, and the vehicle exterior communication area is formed around the vehicle. Form. Then, the verification ECU 9 acquires the ID signal Sid from the electronic key 2 located in the outside communication area and confirms that ID verification, that is, verification outside the vehicle, is established by the ID signal Sid. Lock the lock.

  Therefore, in the case of this example, since the vehicle transmitter 10 is a two-axis integrated antenna, the vehicle 1 side can execute both vehicle exterior verification and vehicle interior verification with a single antenna. For this reason, since only one transmission antenna is prepared for the vehicle 1, the number of antennas of the vehicle 1 can be reduced. In addition, by forming two-axis integrated antennas individually or simultaneously to form communication areas with different directivities, an external communication area and an in-vehicle communication area are formed, so a communication area with a small number of null points can be formed. Become. Therefore, since the communication area complemented with the null point is formed, it is possible to ensure the communication feasibility of smart communication.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) Since the one-component two-axis integrated antenna is used as the vehicle transmitter 10 as a component, the number of transmission antennas installed in the vehicle 1 can be reduced to one. In addition, the coil bar antennas 16a and 16b, which are two-axis integrated antennas, are individually transmitted, and the coil bar antennas 16a and 16b are simultaneously transmitted to form communication areas E1 to E4 having different directivities, thereby performing smart communication. Execute. Therefore, since the vehicle communication area necessary for smart communication can be formed without any problem, the communication establishment of smart communication can be ensured as before.

  (2) When the two coil bar antennas 16a and 16b are simultaneously transmitted to form the vehicle exterior communication area, the coil bar antennas 16a and 16b are simultaneously transmitted in both in-phase and reverse phase. For this reason, directivity communication areas E3 and E4 whose directions are inclined by 90 degrees can be formed, and these areas E3 and E4 can also be used as communication areas outside the vehicle. Therefore, since it is possible to give diversity to the shape of the communication area outside the vehicle, it is possible to further ensure the establishment of smart communication.

  (3) Since the outside communication area and the inside communication area are formed by the two-axis integrated antenna and the position of the electronic key 2 is determined inside or outside the vehicle, it is possible to more accurately determine whether the electronic key 2 is located outside or inside the car. Can be determined.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. This example is different from the first embodiment only in that the transmission intensity of each coil bar antenna 16a, 16b of the two-axis integrated antenna is variable. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts are described in detail.

  As shown in FIG. 6, the verification ECU 9 is provided with a transmission strength switching unit 40 that forms the communication areas E1 to E4 with different transmission strengths. The transmission intensity switching unit 40 sets the sizes of the communication areas E1 to E4 by setting the transmission intensity when the vehicle transmitter 10 forms the communication areas E1 to E4 to different values. In the case of this example, as shown in FIG. 7, the first communication area E1 is formed as a communication area outside the vehicle with a large transmission intensity, and the second communication area E2 to the fourth communication area E4 are small with a weak transmission intensity. Is formed as an in-vehicle communication area. The transmission intensity switching unit 40 corresponds to a communication area changing unit.

  When the vehicle 1 is parked, as shown in FIG. 8A, the request signal Srq is transmitted solely from the first coil bar antenna 16a, and the first communication area E1 is communicated outside the vehicle around the vehicle. Formed as an area. At this time, the transmission strength switching unit 40 forms the first communication area E1 with a strong transmission strength. Accordingly, a first communication area E1, that is, a communication area outside the vehicle, is formed around the vehicle. When the electronic key 2 enters the outside communication area and the outside verification is established, the door lock unlocking is permitted.

  When the driver gets on the vehicle, an in-vehicle communication area is formed in the vehicle as shown in FIG. 8B. At this time, the single transmission of the second coil bar antenna 16b, the in-phase synchronous transmission of the coil bar antennas 16a and 16b, and the anti-phase synchronous transmission are sequentially executed, and the second communication area E2 and the third communication area are executed in the vehicle. E3 and the fourth communication area E4 are formed in order. In the case of this example, the transmission intensity switching unit 40 forms these communication areas E2 to E4 with a weak transmission intensity. For this reason, these communication areas E2 to E4 are formed only in the vehicle, and as a result, this becomes the vehicle communication area.

  Here, when the second communication area E2 is viewed, since the area E2 is apparently an elliptical area, a null point is generated near the tip of the circle. However, since the null point of the second communication area E2 is included in the communication range of the third communication area E3 and the fourth communication area E4, the null point of the second communication area E2 is the third communication area E3 and the fourth communication area. It can be seen that it is complemented by E4. For this reason, when the in-vehicle communication area is formed in the second communication area E2 to the fourth communication area E4 having weak transmission strength, an area in which the entire in-vehicle area is reliably covered is formed. When the electronic key 2 enters the in-vehicle communication area and the in-vehicle collation is established, an engine start operation and a power supply transition operation are permitted.

  Therefore, in this example, the transmission intensity when the vehicle transmitter 10 performs single transmission or simultaneous transmission is switched to form an out-of-vehicle communication area and an in-vehicle communication area. Therefore, these communication areas are set more finely. It becomes possible. Therefore, as in this example, it is possible to form an area by complementing the null point of the in-vehicle communication area, so that the communication establishment of smart communication can be further improved.

According to the configuration of the present embodiment, in addition to the effects (1) to (3) described in the first embodiment, the following effects can be obtained.
(4) The request signal Srq can be transmitted by changing the transmission intensity of the coil bar antennas 16a and 16b between the vehicle communication and the vehicle communication. For this reason, the communication areas E1 to E2 are not formed as simple areas, but are formed as communication areas E1 to E4 corresponding to the vehicle 1, respectively. Can be formed.

  (5) The transmission intensity is kept lower than when forming the first communication area E1 (that is, the communication area outside the vehicle), and radio waves are transmitted from the coil bar antennas 16a and 16b, and the size is smaller than that of the first communication area E1. The second communication area E2 to the fourth communication area E4 are formed as in-vehicle communication areas. Therefore, since it is possible to form an in-vehicle communication area that complements the null point, it is possible to further improve the communication feasibility of in-vehicle collation.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
In the first and second embodiments, the multi-axis integrated antenna is not limited to the two-axis integrated antenna having the two coil bar antennas 16a and 16b. For example, three antenna parts may be provided to provide an antenna corresponding to three axes (X axis, Y axis, Z axis).

  In the first and second embodiments, the coil bar antennas 16a and 16b of the two-axis integrated antenna are not limited to being arranged in the direction in which the coil axes L1 and L2 are orthogonal to each other, and may take an angle other than orthogonal. .

  In the first and second embodiments, the antenna member of the vehicle transmitter 10 is not limited to the coil bar antennas 16a and 16b, and may be, for example, a loop antenna or a dipole antenna.

-In 1st and 2nd embodiment, simultaneous transmission is good also as operation | movement which transmits an electromagnetic wave simultaneously, when two or more antenna members exist, for example.
In the first embodiment, the first communication area E1 may be the outside communication area, the second communication area E2 may be omitted, and the third communication area E3 and the fourth communication area E4 may be the in-vehicle communication area.

-In 1st and 2nd embodiment, what kind of communication area (area size and number) is formed and how a key position is determined can be freely set.
In the first and second embodiments, when the coil bar antennas 16a and 16b are transmitted simultaneously, both the in-phase transmission and the reverse-phase transmission are not necessarily executed, but only one of them may be performed.

In the first and second embodiments, the request signal Srq is not limited to an ID reply request, and may be a signal that requests a response from the electronic key 2.
-In 1st and 2nd embodiment, the electronic key 2 is not limited to a vehicle key, Various terminals (a mobile phone, an IC card, etc.) can be used. Further, the electronic key 2 is not necessarily limited to one having a key function, and widely includes communication terminals (authentication terminals) that require an authentication action in a broad sense.

  In the first and second embodiments, the key operation free system 3 is not limited to having different frequencies in the forward path and the return path of mutual communication, and may have the same frequency. The communication frequency of the key operation free system 3 is not limited to LF and UHF, and other frequencies such as HF (High Frequency) may be used.

  -In 1st and 2nd embodiment, the electric key 2 of the electronic key 2 is transmitted from the vehicle 1 in the process of smart communication, and the electronic key 2 is driven by this electric power electric wave, and it is good also considering the electronic key 2 as a battery-less. .

  -In 1st and 2nd embodiment, an electronic key system is not limited to the key operation free system 3, What is necessary is just what the vehicle 1 and the electronic key 2 perform ID collation by mutual wireless communication.

-In 1st and 2nd embodiment, the key operation free system 3 is not restricted to being mounted in the vehicle 1, but is employable for another apparatus and apparatus.
Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below together with their effects.

(A) In any one of claims 1 to 3 , when the transmission execution means forms a plurality of the communication areas and performs ID verification with the electronic key, when the ID verification is confirmed, Stop communication area formation. According to this configuration, since it is not necessary to form a useless communication area, it is possible to save power of the communication master.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle as communication master, 2 ... Electronic key, 3 ... Key operation free system as electronic key system, 10 ... Vehicle transmitter as multi-axis integrated antenna, 15 ... Communication area forming device, 16a ... Antenna member The first coil bar antenna, 16b ... the second coil bar antenna constituting the antenna member, 18 ... the vehicle exterior communication area forming part constituting the transmission execution means, 19 ... the vehicle interior communication area forming part constituting the transmission execution means, 40 ... Transmission intensity switching part as communication area changing means, L1, L2... Coil axis as axis, E1... First communication area constituting communication area, E2... Second communication area constituting communication area, E3. 3rd communication area which comprises, E4 ... 4th communication area which comprises a communication area.

Claims (3)

In the communication area forming apparatus of the electronic key system that performs ID collation by the ID code returned from the electronic key in response to the ID reply request from the communication master,
A multi-axis integrated antenna provided as at least two antenna members formed as transmitting antennas of the communication master and arranged in different directions in the axial direction;
By individually transmitting radio waves individually from the plurality of antenna members, and simultaneously transmitting radio waves from the plurality of antenna members, communication areas having different directivities are formed, and the ID verification with the electronic key is performed. Transmission execution means for executing
When the transmission execution means forms a plurality of the communication areas and performs ID collation with the electronic key, at the time of confirming the establishment of the ID collation, the subsequent communication area formation is stopped ,
The transmission execution means selectively forms an outdoor communication area and an indoor communication area as the communication area, and confirms whether the ID verification is established in the outdoor communication area or the indoor communication area. It is possible to determine whether the electronic key is located outdoors or indoors. When it is detected that the lock button provided outside the room has been operated, the ID verification with the electronic key in the room as a counterpart first The communication area forming apparatus of the electronic key system is characterized in that ID collation with the electronic key outside the room is executed thereafter . When transmitting the plurality of antenna members at the same time, the transmission execution means simultaneously transmits the antenna members in the same phase and simultaneously transmits the antenna members in the opposite phase, so that the communication areas having the directivity orthogonal to each other can be obtained. The communication area forming apparatus of the electronic key system according to claim 1, wherein the apparatus is formed. 3. The communication area changing means for switching the size of the communication area by changing the transmission intensity of the antenna member when the antenna member forms the communication area. A communication area forming apparatus of the electronic key system described.

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