JP5830365B2 - Electronic key and electronic key system - Google Patents

Description

  The present invention relates to an electronic key and an electronic key system.

  In the conventional electronic key system, locking / unlocking of the vehicle door, engine starting, etc. are permitted through wireless communication between the electronic key and the vehicle-mounted device. The in-vehicle device transmits a request signal to its surroundings. When receiving the request signal, the electronic key transmits a response signal including the ID code. The vehicle-mounted device permits locking / unlocking of the vehicle door when the verification of the ID code included in the response signal from the electronic key is established (see, for example, Patent Document 1).

JP 2002-029385 A

  In recent years, there has been concern about unauthorized communication in which an electronic key that exists far away using a repeater that relays radio waves (request signal, response signal) is disguised as if it exists outside the vehicle interior. Unauthorized communication using this repeater may cause unauthorized unlocking of the vehicle door. For this reason, security technology against unauthorized communication using a repeater has been demanded.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an electronic key and an electronic key system with improved security against unauthorized communication.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
In the first aspect of the invention, when a request signal wirelessly transmitted from the in-vehicle device to the periphery of the vehicle is received, a response signal including its own identification code is wirelessly transmitted to the in-vehicle device to lock and unlock the vehicle door. In the electronic key to be enabled, an acceleration sensor that is built in the electronic key and detects acceleration generated in the electronic key as a user walks, and a response permission state that transmits the response signal to the request signal The operation state is switched between a response prohibition state in which the response signal is not transmitted in response to the request signal, and a certain period of time has elapsed since the user determined that the user stopped after walking based on the detection result of the acceleration sensor. said a response permission state, except it includes a control unit serving as the response inhibition state, the vehicle apparatus The switch transmits the request signal when an on-vehicle switch that can be operated from outside the vehicle is operated. When the control unit receives the request signal in the response prohibited state, the control unit receives the request signal and transmits the response signal. The main point is to stop the electronic key function according to the above.

Generally, when opening a vehicle door, the user stops once in front of the vehicle door. According to the said structure, it is set as the response permission state which can transmit a response signal with respect to a request signal only for a fixed time, when a user stops after a walk. Thus, by limiting the time of the response permission state, the transmission of the response signal from the electronic key through unauthorized communication using the relay device described in the background art is suppressed. Therefore, security is improved.
Also, the user approaching the vehicle stops when operating the switch. For this reason, normally, when the switch is operated, and when a request signal is transmitted, the response is permitted. For this reason, there is a possibility that the request signal received in the response prohibited state is an invalid request signal. According to the above configuration, the electronic key control unit stops the electronic key function when receiving the request signal in the response prohibited state. As a result, for example, even if the user stops accidentally during a period in which an invalid request signal is continuously transmitted to the electronic key held by the user at a position away from the vehicle, the fraud immediately after stopping A response signal is not transmitted in response to a request signal. Therefore, security can be improved.

The invention according to claim 2 is characterized in that the electronic key according to claim 1 is provided with a notification means for notifying the user when the electronic key function is stopped.
According to this configuration, when the electronic key function is stopped, the user is notified through the notification means. Therefore, the user can recognize that the electronic key function has stopped.

According to a third aspect of the present invention, in the electronic key according to the first or second aspect , the control unit performs a specific operation on the electronic key in a state where the electronic key function is stopped. When the determination is made, the gist is to cancel the state where the electronic key function is stopped.

  According to this configuration, even when the electronic key function is stopped, the state where the electronic key function is stopped can be released through a specific operation on the electronic key. Therefore, only a legitimate user can cancel the electronic key function stop state.

The invention according to claim 4 is a vehicle-mounted device that wirelessly transmits a request signal around the vehicle, and an electronic key that wirelessly transmits a response signal including its own identification code to the vehicle-mounted device when the request signal is received; And the vehicle-mounted device is capable of locking and unlocking a vehicle door when verification of an identification code included in the received response signal is established, wherein the electronic key is built in the electronic key. In addition, an acceleration sensor that detects acceleration generated in the electronic key as the user walks, and an information signal including a detection result of the acceleration sensor are wirelessly transmitted to the in-vehicle device, and the response signal is transmitted to the request signal. It operates between a response permission state to be transmitted and a response prohibition state in which the response signal is not transmitted in response to the request signal. Together state is switched, said user based on a detection result of the acceleration sensor becomes the response permission state over a predetermined time from the time it is determined that it has stopped after walking, the electronic key controller otherwise serving as the response inhibition state And the in-vehicle device includes a control prohibited state for restricting locking / unlocking of the vehicle door through reception of the response signal, and a control permission state for permitting locking / unlocking of the vehicle door through reception of the response signal. The operation state is switched between and the control permission state is set for a certain period of time after the user determines that he / she has stopped after walking based on the detection result of the acceleration sensor included in the received information signal. includes a vehicle control unit serving as the control prohibition condition other than, the switch further the vehicle-mounted device, which is operably vehicle from outside the vehicle Transmitting the request signal when operated, the electronic key control unit in the response inhibition state, when receiving the request signal, to stop the electronic key function related to the transmission of the reception and the response signal of the request signal That is the gist.

Generally, when opening a vehicle door, the user stops once in front of the vehicle door. According to the said structure, it will be in the control permission state which permits locking / unlocking of a vehicle door through reception of a response signal only for a fixed time after the user stops after a walk. In this way, by limiting the time in the control permission state, it is possible to suppress locking and unlocking of the vehicle door through unauthorized communication using the repeater described in the background art. Therefore, security is improved.
In addition, according to the above configuration, a response permission state in which a response signal can be transmitted with respect to the request signal only for a predetermined time from when the user stops after walking is set. Thus, by limiting the time of the response permission state, the transmission of the response signal from the electronic key through unauthorized communication using the relay device described in the background art is suppressed. Therefore, security is improved.
Also, the user approaching the vehicle stops when operating the switch. For this reason, normally, when the switch is operated, and when a request signal is transmitted, the response is permitted. For this reason, there is a possibility that the request signal received in the response prohibited state is an invalid request signal. According to the above configuration, the electronic key control unit stops the electronic key function when receiving the request signal in the response prohibited state. As a result, for example, even if the user stops accidentally during a period in which an invalid request signal is continuously transmitted to the electronic key held by the user at a position away from the vehicle, the fraud immediately after stopping A response signal is not transmitted in response to a request signal. Therefore, security can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the security with respect to unauthorized communication can be improved in an electronic key and an electronic key system.

1 is a block diagram showing a configuration of an electronic key system according to an embodiment of the present invention. The graph which showed transition of the detected acceleration concerning one embodiment of the present invention. 1 is a top view of a vehicle according to an embodiment of the present invention. The flowchart which shows the process sequence which concerns on the switching of the state of the electronic key control part which concerns on one Embodiment of this invention.

Hereinafter, an electronic key system according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the electronic key system 1 includes an electronic key 10 possessed by a driver of the vehicle 2 and an in-vehicle device 20 provided in the vehicle 2. Mutual communication is automatically performed between the electronic key 10 and the vehicle-mounted device 20, and the locking and unlocking of the vehicle door is permitted on the condition that the mutual communication is established. Hereinafter, the configuration of the electronic key 10 and the in-vehicle device 20 will be described.

<Electronic key 10>
The electronic key 10 includes an electronic key control unit 11, an LF reception unit 12, a UHF transmission unit 13, an acceleration sensor 18, a locking switch 14, an unlocking switch 15, and a vibrator 19.

  The electronic key control unit 11 is configured by a computer unit and includes a nonvolatile memory 11a. In this memory 11a, an ID code unique to the electronic key 10 is stored.

  When the LF receiving unit 12 receives a request signal, which is an LF band radio signal transmitted from the vehicle-mounted device 20 through its own receiving antenna 12a, the LF receiving unit 12 demodulates the signal and outputs it to the electronic key control unit 11.

  When receiving the request signal from the LF receiver 12, the electronic key controller 11 recognizes whether it is in a response permission state or a response inhibition state. When the electronic key control unit 11 recognizes that it is in a response permission state, the electronic key control unit 11 generates a response signal including an ID code stored in the memory 11 a and outputs the response signal to the UHF transmission unit 13. The UHF transmission unit 13 modulates the response signal from the electronic key control unit 11 into a UHF (Ultra High Frequency) band, and wirelessly transmits the response signal to the in-vehicle device 20 through its own transmission antenna 13a.

Even when the electronic key control unit 11 receives the request signal, if the electronic key control unit 11 recognizes that the electronic key control unit 11 is in a response prohibited state, the electronic key control unit 11 ends the process without generating a response signal.
The locking switch 14 and the unlocking switch 15 are provided on the surface of the electronic key 10 so as to be pressed by the user. When the lock switch 14 or the unlock switch 15 is pressed, an operation signal to that effect is output to the electronic key control unit 11.

  When the electronic key control unit 11 recognizes that the lock switch 14 has been pressed, the electronic key control unit 11 sends a lock request signal for requesting locking of the vehicle door via the UHF transmission unit 13 via the UHF transmission unit 13 in the same manner as the response signal. Send as a signal. When the electronic key control unit 11 recognizes that the unlocking switch 15 has been pressed, the electronic key control unit 11 sends an unlock request signal for requesting the unlocking of the vehicle door via the UHF transmission unit 13 in the same manner as the response signal. And transmitted as a radio signal in the UHF band.

  The acceleration sensor 18 detects the movement of the electronic key 10 as acceleration. The acceleration sensor 18 may be a mechanical type, an optical type, a semiconductor type, or the like, but may be any type as long as it can be incorporated in the electronic key 10 and can detect acceleration. Further, the detection axis of the acceleration sensor may be any one of 1 axis to 3 axes.

The vibrator 19 vibrates the electronic key 10 under the control of the electronic key control unit 11.
As shown in the graph of FIG. 2, the acceleration sensor 18 detects the acceleration generated in the electronic key 10 as a signal (voltage value) corresponding to the acceleration, and outputs the detection result to the electronic key control unit 11. The electronic key control unit 11 switches between a response permission state and a response prohibition state based on the detection result of the acceleration sensor 18.

  The electronic key control unit 11 is normally in a response prohibited state. Specifically, as shown in the graph of FIG. 2, the electronic key control unit 11 maintains the response prohibited state when detecting an acceleration equal to or greater than a certain value Gth over a certain time T1. The acceleration at this time is associated with the walking of the user who holds the electronic key 10. When the electronic key control unit 11 determines that the acceleration is less than the predetermined value Gth, the electronic key control unit 11 enters a response permission state over the response permission time Ta. At this time, it is assumed that the user who holds the electronic key 10 stops in front of the vehicle door as the lock switch 32 is operated. That is, the response permission time Ta is set to a time during which the lock switch 32 can be operated after the user stops. In addition, when the period during which the acceleration greater than or equal to the certain value Gth is detected is less than the certain time T1, the electronic key control unit 11 assumes that the acceleration does not accompany the user's walking, and thereafter the acceleration is a certain value. Even if it becomes less than Gth, the response is not permitted.

  When the electronic key control unit 11 determines that the response permission time Ta has elapsed, the electronic key control unit 11 enters the response prohibited state again. At this time, it is expected that the electronic key 10 is left unattended, or the user who owns the electronic key 10 has stopped for a long period of time.

  In addition, the electronic key control unit 11 stops the electronic key function when receiving a request signal in a response prohibited state when detecting an acceleration of a certain value Gth or more. When the electronic key function is stopped, the electronic key control unit 11 vibrates the electronic key 10 through the vibrator 19 to notify the user that the electronic key function has been stopped. In the electronic key function stop state, the electronic key control unit 11 stops receiving the request signal and transmitting the response signal by stopping the power supply to the LF reception unit 12, the UHF transmission unit 13, and the acceleration sensor 18. The operation signal from the locking switch 14 and the unlocking switch 15 is monitored while being in a possible state. When the electronic key control unit 11 determines that a specific release operation has been performed based on the operation signals from the lock switch 14 and the unlock switch 15, the electronic key control unit 11 releases the function stop state of the electronic key 10. As this specific releasing operation, for example, pressing the locking switch 14 and the unlocking switch 15 in order, or simultaneously pressing the locking switch 14 and the unlocking switch 15 for a certain time or more, can be considered.

<In-vehicle device 20>
As shown in FIG. 1, the in-vehicle device 20 includes an in-vehicle control unit 21, an out-of-vehicle transmission unit 22, and an in-vehicle reception unit 24.

  The in-vehicle control unit 21 is configured by a computer unit and includes a nonvolatile memory 21a. The memory 21a stores an ID code unique to the electronic key 10 registered in the vehicle and a program to be described later.

In addition, a lock switch 32 and a door lock device 34 are electrically connected to the in-vehicle control unit 21.
As shown in FIG. 3, the lock switch 32 is provided on the outside door handle and outputs an operation signal to that effect to the in-vehicle control unit 21 when pressed. The door lock device 34 locks and unlocks the vehicle door based on a control signal from the in-vehicle control unit 21.

  As shown in FIG. 1, when the in-vehicle control unit 21 recognizes that the lock switch 32 has been pressed based on the operation signal, the in-vehicle control unit 21 generates a request signal and outputs the signal to the outside transmission unit 22. The outside transmission unit 22 modulates the request signal from the in-vehicle control unit 21 into an LF (Low Frequency) band, and transmits the modulated request signal to the communication area 50 (see FIG. 3) around the vehicle 2 through the transmission antenna 22a. To do.

  When receiving the response signal transmitted from the electronic key 10 via the receiving antenna 24a, the in-vehicle receiving unit 24 demodulates the signal and outputs it to the in-vehicle control unit 21. When receiving the response signal from the in-vehicle receiver 24, the in-vehicle controller 21 collates the ID code included in the signal with the ID code stored in the memory 21a.

When it is determined that ID code verification has been established, the in-vehicle control unit 21 transmits a control signal to the door lock device 34 to switch the lock / unlock state of the vehicle door.
Further, when receiving the lock request signal or the unlock request signal transmitted from the electronic key 10 via the receiving antenna 24a, the in-vehicle receiving unit 24 demodulates the signal and outputs it to the in-vehicle control unit 21. When receiving the lock request signal or the unlock request signal from the in-vehicle receiving unit 24, the in-vehicle control unit 21 collates the ID code included in the signal with the ID code stored in the memory 21a.

  When it is determined that the ID code verification in the locking request signal has been established, the in-vehicle control unit 21 locks the vehicle door by transmitting a control signal to the door lock device 34. Similarly, when it is determined that the ID code verification in the unlock request signal has been established, the in-vehicle controller 21 unlocks the vehicle door by transmitting a control signal to the door lock device 34.

  Next, a processing procedure related to switching of the state of the electronic key control unit 11 will be described with reference to a flowchart shown in FIG. The flowchart is executed in accordance with a program stored in advance in the memory 11a, and is started when an acceleration of a certain value G or more is detected. At the start of this flowchart, the electronic key control unit 11 is in a response prohibited state.

  The electronic key control unit 11 determines whether or not the acceleration of a certain value G or more is maintained for a certain time T1 or more (S101). When the electronic key control unit 11 determines that the acceleration of a certain value G or more is not maintained for a certain time T1 or more (NO in S101), the acceleration generated in the electronic key 10 is not associated with the user's walking. Then, the process is terminated while maintaining the response prohibited state.

  When the electronic key control unit 11 determines that the acceleration of a certain value G or more is maintained for a certain time T1 or more as the user walks (YES in S101), the acceleration of the certain value G or more is maintained. It is determined whether a request signal has been received during the period (S102). When the electronic key control unit 11 determines that a request signal has been received during that period (YES in S102), the electronic key control unit 11 stops the electronic key function (S103) and terminates the processing because there is a possibility of an illegal request signal. . This electronic key function stop state can be released through the specific release operation described above.

  When it is determined that the request signal is not received during the period (NO in S102), the electronic key control unit 11 determines whether or not the acceleration is less than a certain value G (S104). When the electronic key control unit 11 determines that the acceleration is less than the predetermined value G by the user holding the electronic key 10 being stopped (YES in S104), the electronic key control unit 11 switches to the response permission state over the response permission time Ta ( S105). The electronic key 10 returns a response signal to the request signal only during the response permission time Ta. Thereafter, the electronic key control unit 11 again switches to the response prohibited state (S106), and ends the process.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) Generally, when unlocking a vehicle door, the user stops once in front of the vehicle door in order to operate the lock switch 32. According to the said structure, the electronic key control part 11 will be in the response permission state which can transmit a response signal only during response permission time Ta from when a user stopped after a walk. Thus, by limiting the time of the response permission state, transmission of the response signal from the electronic key 10 through unauthorized communication using the relay device described in the background art is suppressed. Therefore, security can be improved.

  In addition, by limiting the time in the response permission state, the number of response signal transmissions relative to the number of request signal receptions can be reduced. Therefore, power consumption of the electronic key 10 can be reduced.

  (2) As described above, the user approaching the vehicle 2 stops when operating the lock switch 32. For this reason, normally, when the lock switch 32 is operated, and when a request signal is transmitted, the electronic key control unit 11 is in a response permission state. For this reason, there is a possibility that the request signal received in the response prohibited state is an invalid request signal. The electronic key control unit 11 stops the electronic key function when receiving a request signal in a response prohibited state during a period in which an acceleration of a certain value G or more is maintained. As a result, for example, even if the user stops accidentally during a period in which unauthorized request signals are continuously transmitted to the electronic key 10 possessed by the user at a position away from the vehicle 2, A response signal is not transmitted in response to an invalid request signal. Therefore, security can be improved. Similarly to the above, the power consumption of the electronic key 10 can be reduced through a reduction in the number of response signal transmissions.

  (3) When the electronic key function is stopped, the user is notified through the vibration of the vibrator 19. Therefore, the user can recognize that the electronic key function has stopped. Accordingly, the user may recognize that the stop of the electronic key function is not caused by the failure of the electronic key 10 and that an invalid request signal may be transmitted to the electronic key 10. it can.

  (4) Even when the electronic key function is stopped, the state in which the electronic key function is stopped can be canceled through a specific operation on the electronic key 10. Therefore, only a legitimate user can cancel the electronic key function stop state.

  (5) In the stop state of the electronic key function, power supply to the LF receiver 12, the UHF transmitter 13, and the acceleration sensor 18 is stopped. Therefore, power consumption of the electronic key 10 can be reduced.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, when a specific release operation is performed on the lock switch 14 and the unlock switch 15, the electronic key function stop state is released. However, the specific release operation is not limited to this, and may be a swing operation of the electronic key 10, for example. In this case, the electronic key control unit 11 supplies power to the acceleration sensor 18 even when the electronic key function is stopped, and monitors the detection result of the acceleration sensor 18. In this configuration, the locking switch 14 and the unlocking switch 15 can be omitted. Accordingly, a wireless key system that locks and unlocks the vehicle door through the switch operation of the electronic key 10 can be omitted. Further, the swinging operation may be performed together with the pressing operation of the lock switch 14 or the unlock switch 15.

  Further, if it is a three-axis acceleration sensor, the electronic key control unit 11 can detect the trajectory of the swing operation of the electronic key 10. Therefore, when the electronic key control unit 11 determines that the trajectory of the swing operation of the electronic key 10 satisfies a specific condition (for example, it is swung in an arc shape), the electronic key control unit 11 may cancel the electronic key function stop state. Complicating a specific release operation makes it difficult for a non-authorized user to perform the release operation, thereby improving security.

  Further, the configuration in which the electronic key function stop state is released through a specific release operation may be omitted. In this case, for example, it is conceivable to adopt a configuration in which the electronic key function is automatically released from a stopped state after a certain period of time has elapsed.

  In the above embodiment, the electronic key control unit 11 stops power supply to the LF reception unit 12, the UHF transmission unit 13, and the acceleration sensor 18 in a state where the electronic key function is stopped. May be continued.

  In the above embodiment, when the electronic key function is stopped, the electronic key control unit 11 notifies the user that the electronic key function has been stopped through vibration of the vibrator 19 serving as a notification unit. However, as long as the user can be notified, the notification may be performed through, for example, voice or display. When notifying by voice, a speaker is provided on the electronic key 10, and when notifying by display, a display or LED (light emitting diode) is provided on the electronic key 10. The various notification means may be combined as appropriate. Furthermore, the notification means may be omitted from the electronic key 10 to notify the user that the electronic key function has stopped.

  In the above embodiment, the electronic key control unit 11 switches between the response permission state and the response prohibition state. However, the in-vehicle control unit 21 switches between a control prohibited state in which locking / unlocking of the vehicle door through reception of the response signal is controlled and a control permission state in which locking / unlocking of the vehicle door through reception of the response signal is permitted. Also good. In this case, for example, the electronic key control unit 11 wirelessly transmits an information signal including the detection result of the acceleration sensor 18 to the in-vehicle device 20 over a certain period from reception of the request signal. The vehicle-mounted control unit 21 is in a control-permitted state for a certain period of time from when the user determines that he / she has stopped after walking based on the detection result of the acceleration sensor 18 included in the received information signal, and otherwise control is prohibited. It becomes a state. Also with this configuration, the vehicle door can be unlocked only for a certain period of time after the user stops after walking. Therefore, it is possible to suppress locking / unlocking of the vehicle door through unauthorized communication using the relay machine, and to improve security.

  In the above embodiment, the request signal is transmitted with the operation of the lock switch 32 of the vehicle 2 as a trigger. However, the in-vehicle controller 21 may transmit a request signal at regular intervals when the electronic key 10 is expected to exist outside the vehicle based on the vehicle state such as the engine state and the vehicle door open / close state. In this configuration, it is desirable to omit the configuration that stops the electronic key function when a request signal is received in the response prohibited state.

  In the above embodiment, the electronic key control unit 11 is in a response-permitted state when the acceleration becomes less than the certain value Gth after detecting the acceleration of the certain value Gth or more over the certain time T1. However, the restriction on the predetermined time T1 may be omitted. In this case, the electronic key control unit 11 enters a response permission state when the acceleration becomes less than the predetermined value Gth after detecting the acceleration equal to or higher than the predetermined value Gth.

  In the above embodiment, when the electronic key control unit 11 receives a request signal in a response prohibited state when detecting an acceleration of a certain value Gth or more, the function of the electronic key is stopped. However, the case where the function of the electronic key is stopped is not limited to this, for example, a response prohibited state other than when an acceleration of a certain value Gth or more is detected (for example, after the response permission time Ta in FIG. 2 elapses). The function of the electronic key may also be stopped when a request signal is received at.

  In the above embodiment, the electronic key 10 is configured independently, but a mobile phone having this electronic key function may be used. This mobile phone may be a so-called smartphone.

Next, the technical idea that can be grasped from the embodiment will be described together with the effects.
(B) In the electronic key, the control unit, in the response inhibition state when that detects acceleration caused by walking, when receiving the request signal, according to the transmission of the reception and the response signal of the request signal to stop the electronic key function.

  DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 2 ... Vehicle, 10 ... Electronic key, 11 ... Electronic key control part, 14 ... Locking switch, 15 ... Unlocking switch, 18 ... Acceleration sensor, 19 ... Vibrator, 20 ... In-vehicle apparatus, 21 ... In-vehicle control unit, 32 ... lock switch.

Claims (4)

In an electronic key that enables locking and unlocking of a vehicle door by wirelessly transmitting a response signal including its own identification code to the vehicle-mounted device when receiving a request signal wirelessly transmitted from the vehicle-mounted device to the periphery of the vehicle,
An acceleration sensor that is built in the electronic key and detects acceleration generated in the electronic key as the user walks;
The operation state is switched between a response permission state in which the response signal is transmitted in response to the request signal and a response prohibition state in which the response signal is not transmitted in response to the request signal. user becomes the response permission state over a predetermined time from the time it is determined that it has stopped after walking, is provided with a control unit to be the response inhibition state otherwise,
The in-vehicle device transmits the request signal when a switch mounted on the vehicle to be operated from outside the vehicle is operated,
When the control unit receives the request signal in the response prohibited state, the control unit stops an electronic key function related to reception of the request signal and transmission of the response signal . The electronic key according to claim 1 , wherein
An electronic key comprising notifying means for notifying the user when the electronic key function is stopped. The electronic key according to claim 1 or 2 ,
When the electronic control unit determines that a specific operation has been performed on the electronic key while the electronic key function is stopped, the control unit releases the electronic key function from being stopped. An in-vehicle device that wirelessly transmits a request signal to the periphery of the vehicle, and an electronic key that wirelessly transmits a response signal including its identification code to the in-vehicle device when the request signal is received. In the electronic key system that enables locking and unlocking of the vehicle door when verification of the identification code included in the response signal is established,
The electronic key is
An acceleration sensor that is built in the electronic key and detects acceleration generated in the electronic key as the user walks;
A response permission state in which an information signal including a detection result of the acceleration sensor is wirelessly transmitted to the in-vehicle device and the response signal is transmitted in response to the request signal, and a response in which the response signal is not transmitted in response to the request signal The operation state is switched between the prohibited state and the response is permitted for a certain period of time after the user determines that the user has stopped after walking based on the detection result of the acceleration sensor. An electronic key control unit to be in a state ,
The in-vehicle device has an operation state between a control prohibited state for restricting locking / unlocking of the vehicle door through reception of the response signal and a control permission state for permitting locking / unlocking of the vehicle door through reception of the response signal. The control is permitted for a certain period of time after the user determines that he / she has stopped after walking based on the detection result of the acceleration sensor included in the received information signal, and the control is prohibited otherwise. Equipped with an in- vehicle control unit
Further, the in-vehicle device transmits the request signal when a switch mounted on the vehicle to be operated from outside the vehicle is operated,
The electronic key control unit stops an electronic key function related to reception of the request signal and transmission of the response signal when receiving the request signal in the response prohibited state .