JP2013050010A - Electronic key - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic key for enabling smooth operation of electronic equipment through the reception/transmission of radio signals even when a power supply is exhausted.SOLUTION: The electronic key comprises: a solar panel 27; a capacitor 26b which can be charged with electricity generated by the solar panel 27; and an electronic key control part 21 for receiving/transmitting radio signals from/to a vehicle 10 while consuming the electric power of the capacitor 26b, the electronic key control part 21 serving for operating/permitting the operation of various door lock devices 14 mounted on the vehicle 10 through the reception/transmission of the radio signals. The electronic key control part 21 prohibits the transmission of the radio signals when the voltage of the capacitor 26b is lower than a voltage threshold value required for completing the transmission of the radio signals, and permits the transmission start of the radio signals when the voltage of the capacitor 26b reaches the voltage threshold value with charging operation.

Description

  The present invention relates to an electronic key.

  In recent years, in automobiles, for the purpose of improving convenience, wireless communication is performed between an electronic key possessed by a user and an in-vehicle device, and door locking / unlocking is permitted on condition that the wireless communication is established. Alternatively, an electronic key system to be executed is mounted. As shown in Patent Document 1, the electronic key system includes a smart system that automatically executes the previous wireless communication just by the user having the electronic key approaching the vehicle, and a switch provided on the electronic key. There is a wireless system that is executed when it is operated. Many automobiles have both of these systems. In this case, since the user can select and use the smart system and the wireless system according to his / her situation, it is convenient to use.

JP 2009-2111

  Usually, the electronic key is equipped with a replaceable battery (primary battery). The electronic key generates wireless signals by consuming battery power and performs wireless communication (smart communication and wireless communication) with the vehicle. In such an electronic key, when the battery is exhausted, both the smart system and the wireless system cannot be used.

  In view of this, it has been considered that the electronic key is provided with power generation means such as a solar panel and power storage means such as a capacitor for storing electric power generated by the power generation means in addition to the primary battery. When the battery is depleted, the electronic key consumes the power of the power storage means to generate a wireless signal and performs wireless communication with the vehicle.

  However, in such an electronic key, there is a possibility that communication with the vehicle may be started even if the amount of power stored in the power storage means is not sufficient to complete the wireless communication. In this case, the electronic key cannot perform wireless communication on the way, and consequently cannot lock and unlock the vehicle door. This is inconvenient for the user.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electronic key that can smoothly operate an electronic device through transmission / reception of a wireless signal even when the power is consumed. .

  In order to solve the above-mentioned problem, the invention of claim 1 includes a power generation means, a power storage means that can be charged by electricity generated by the power generation means, a communication master that consumes power of the power storage means, Control means for transmitting / receiving a wireless signal between the electronic keys, and the control means in the electronic key for operating or permitting the operation of various electronic devices mounted on the communication master through the transmission / reception of the wireless signal. The means forbids transmission of the wireless signal when the amount of electricity stored in the electricity storage means is below a power threshold necessary to complete transmission of the wireless signal, and the amount of electricity stored in the electricity storage means is reduced by the charging. When the threshold is reached, the gist is to allow the start of transmission of the radio signal.

  If transmission of the wireless signal is started in a state where the amount of power stored in the power storage means is less than the power threshold, the transmission cannot be continued. For this reason, the electronic device of a communication master cannot be operated or an operation | movement cannot be permitted. In that regard, according to the same configuration, the electronic key does not start transmission of a radio signal when the amount of power stored in the power storage means is below the power threshold. That is, the transmission of the radio signal is not started until the power required for the transmission of the radio signal is accumulated. For this reason, transmission of a radio signal during charging is suppressed. Thus, wasteful consumption of the electric power of the power storage unit is suppressed while the power storage unit is being charged. Therefore, the time required for the power storage means to be charged to the power threshold is shortened. For this reason, the user can operate the electronic device smoothly even when the power storage means is consumed.

The invention according to claim 2 is characterized in that, in the electronic key according to claim 1, the amount that can be stored by the power storage means is a power threshold value.
According to this configuration, the amount that can be stored in the power storage means is minimized. Therefore, it takes less time to complete charging. For this reason, it becomes possible to transmit a radio signal with short-time charging.

  According to a third aspect of the present invention, in the electronic key according to the first or second aspect, the electronic key includes a switch that can be operated from the outside, and the control means is triggered by the operation of the switch. The gist is to consume the power of the means, transmit the wireless signal to the communication master, and operate the electronic device through the transmission of the wireless signal.

According to this configuration, it is possible to suppress power consumption of the power storage means provided in the electronic key that performs so-called wireless communication.
According to a fourth aspect of the present invention, in the electronic key according to any one of the first to third aspects, the control means is triggered by reception of a wireless signal requesting a response from the communication master. The gist of the invention is to consume power of the power storage means, transmit a wireless signal as a response to the wireless signal, and operate or permit the operation of the electronic device through the transmission and reception of the wireless signal.

According to this configuration, it is possible to suppress power consumption of the power storage means provided in the electronic key that performs so-called smart communication.
The gist of the fifth aspect of the present invention is that, in the electronic key according to the fourth aspect, the wireless signal from the communication master is not received when the power storage amount of the power storage means is lower than the power threshold.

According to the configuration, by stopping reception, it is possible to suppress power consumption necessary for the reception.
According to a sixth aspect of the present invention, in the electronic key according to any one of the first to fifth aspects, in addition to the power storage means, a replaceable primary battery is provided, and the electric power of the primary battery is supplied. The gist is to consume and transmit the radio signal.

  According to this configuration, since the wireless signal can be transmitted using the power of the primary battery, it is not necessary to generate power by the power generation means each time the wireless signal is transmitted.

  According to the present invention, it is possible to provide an electronic key that can smoothly operate an electronic device through transmission / reception of a wireless signal even when the power is consumed.

The block diagram which shows the structure of the electronic key system in this embodiment. The sequence chart which shows the wireless communication aspect of the vehicle and electronic key in this embodiment. The sequence chart which shows the wireless communication aspect of the vehicle and electronic key in a prior art form.

Hereinafter, an embodiment embodying an electronic key system according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 10 is equipped with an electronic key system 1 that executes ID verification using a radio signal communicated with the electronic key 20. The electronic key system 1 includes a smart communication function (first communication function) that executes ID verification using a radio signal from the vehicle 10 as a trigger, and a wireless communication function that executes ID verification using a radio signal from the electronic key 20 as a trigger. (Second communication function).

<Vehicle configuration>
The vehicle 10 includes an in-vehicle control unit 11 that controls various in-vehicle devices, an LF transmission unit 12 that is electrically connected to the in-vehicle control unit 11 and transmits a request signal of an LF (Low Frequency) band, and a UHF (Ultra). And a UHF receiver 13 for receiving a response signal of the High Frequency) band and the wireless signal Swi. The request signal is a generic term for the wake signal Swk, the vehicle signal Svi, and the challenge signal Sch, and the response signal is a generic term for the ACK signal Sac and the response signal Sre. The vehicle 10 also includes a door lock device 14 and a door handle sensor 15 that are also electrically connected to the in-vehicle controller 11. The door lock device 14 switches between locking and unlocking the door lock. The door handle sensor 15 detects contact of a user with a door handle (not shown).

  The in-vehicle control unit 11 is provided with a nonvolatile memory 11a. An ID code unique to the vehicle 10 is stored in the memory 11a. The in-vehicle controller 11 performs wireless communication with the electronic key 20 through the LF transmitter 12 and the UHF receiver 13. The in-vehicle control unit 11 determines whether or not the electronic key 20 that is in communication corresponds to itself through transmission / reception of a radio signal performed with the electronic key 20. This determination is made by collating the ID code included in the wireless signal from the electronic key 20 with the ID code stored in the memory 11a. And when it is judged that it corresponds to self, operation of door lock device 14 is permitted or performed. Specifically, when the in-vehicle control unit 11 determines that the electronic key 20 corresponds to itself through reception of a response signal from the electronic key 20, the in-vehicle control unit 11 permits the operation of the door lock device 14. In this state, when contact with the door handle is detected through the door handle sensor 15, the in-vehicle controller 11 executes the operation of the door lock device 14. On the other hand, when the in-vehicle control unit 11 determines that the electronic key 20 corresponds to itself through reception of the wireless signal Swi from the electronic key 20, the in-vehicle control unit 11 operates the door lock device 14.

<Structure of electronic key>
The electronic key 20 includes an electronic key control unit 21 configured by a computer unit including a CPU or the like. The electronic key control unit 21 is electrically connected to an LF reception unit 22 that receives a radio signal in the LF band and a UHF transmission unit 23 that transmits a radio signal in the UHF band.

  When receiving the request signal, which is an LF band radio signal transmitted from the vehicle 10, the LF receiving unit 22 demodulates the request signal into a pulse signal and outputs the demodulated signal to the electronic key control unit 21.

  The electronic key control unit 21 includes a nonvolatile memory 21a, and an ID code unique to the electronic key 20 is stored in the memory 11a. When the electronic key control unit 21 recognizes the request signal demodulated by the LF receiving unit 22, the electronic key control unit 21 generates a response signal. To be exact, if the recognized signal is the wake signal Swk, the ACK signal Sac indicating that the signal has been received, and if the recognized signal is the vehicle signal Svi, the ACK signal Sac indicating that the signal has been received. If the recognized signal is the challenge signal Sch, a response signal Sre as a response to the signal is generated. The response signal Sre includes the ID code stored in the memory 21a. The electronic key control unit 21 outputs the generated response signal to the UHF transmission unit 23. The UHF transmitter 23 modulates the response signal and transmits the modulated response signal as a radio signal in the UHF band.

  The electronic key 20 includes a lock switch 24 and an unlock switch 25. These switches 24 and 25 are electrically connected to the electronic key control unit 21. When the lock switch 24 or the unlock switch 25 is operated and an electric signal indicating that is inputted, the electronic key control unit 21 locks or unlocks the ID code stored in the memory 21a and the vehicle door. The wireless signal Swi including the operation content to be shown is generated, and this signal is output to the UHF transmitter 23. The UHF transmitter 23 modulates the wireless signal Swi and transmits the modulated wireless signal Swi as a radio signal in the UHF band. The wireless signal Swi is a signal in which four frames are continuous. Each frame includes an ID code and an operation content indicating that the vehicle door is locked or unlocked. Usually, the vehicle-mounted control unit 11 intermittently switches the state of the UHF receiving unit 13 between a standby state in which radio signals can be received and a non-standby state in which reception is disabled.

  Furthermore, the electronic key 20 includes a power supply unit 26 and a solar panel 27. The power supply unit 26 includes a replaceable battery (primary battery) 26a and a capacitor 26b that can be charged and discharged. The power supply unit 26 supplies the power of the battery 26 a or the capacitor 26 b to each part of the electronic key 20 such as the electronic key control unit 21. The electronic key control unit 21 operates by consuming electric power supplied from the power supply unit 26. The electronic key control unit 21 monitors the voltage of the capacitor 26b. Through the monitoring, the electronic key control unit 21 determines the consumption of the capacitor 26b. When it is determined that the capacitor 26b is not consumed, the electronic key control unit 21 supplies power to itself from the capacitor 26b. When it is determined that the capacitor 26b is consumed, the electronic key control unit 21 supplies power to itself from the battery 26a. Here, the voltage threshold, which is a criterion for determining whether or not the capacitor 26b is consumed, is a voltage at which the response signal to the vehicle 10 or the wireless signal Swi cannot be transmitted.

  A solar panel 27 is connected to the capacitor 26b. The solar panel 27 is provided on the outer surface of the case of the electronic key 20. When the solar panel 27 is irradiated with light such as sunlight, the solar panel 27 generates power using the light energy. The generated power is stored in the capacitor 26b. Note that the amount of power stored in the capacitor 26b is the amount of power that can transmit the wireless signal Swi only once. That is, the amount of electricity stored in the capacitor 26b is small. For this reason, if the solar panel 27 is irradiated with sunlight, charging of the capacitor 26b is completed in a few seconds. Note that a voltage in a state where the capacitor 26b is fully charged is a wireless communication startable voltage V2 (hereinafter, referred to as a second voltage V2).

  The electronic key 20 includes a switching unit 28 that switches the state of the LF receiving unit 22 between a standby state in which radio signal reception is enabled and a non-standby state in which radio signal reception is disabled. . The switching unit 28 is electrically connected to the electronic key control unit 21 and is controlled by the electronic key control unit 21. The electronic key control unit 21 switches the LF reception unit 22 to the standby state through the switching unit 28 when the power supply to the electronic key control unit 21 is performed from the battery 26a. Further, when the power supply to itself is performed from the capacitor 26b and the voltage of the capacitor 26b exceeds the smart communication startable voltage V1 (hereinafter referred to as the first voltage V1), the LF receiving unit is switched through the switching unit 28. 22 is switched to a standby state. The first voltage V1 is a voltage required for the electronic key control unit 21 to execute a series of smart communications performed with the vehicle 10 once. The first voltage V1 is smaller than the second voltage V2 (V1 <V2). On the other hand, when the power supply to itself is performed from the capacitor 26b and falls below the first voltage V1, the LF reception unit 22 is switched to the non-standby state through the switching unit 28.

  Further, the electronic key 20 includes a changeover switch 29 that can be operated from the outside. The changeover switch 29 switches on / off of the smart communication function. The changeover switch 29 is electrically connected to the electronic key control unit 21. When the changeover switch 29 is operated, the electronic key control unit 21 causes the LF reception unit 22 to be in a standby state and a non-standby state through the switching unit 28. Switch between. The electronic key control unit 21 is in the case where the changeover switch 29 is turned on, and when the power supply to itself is performed from the battery 26a or the power supply to itself is performed from the capacitor 26b, the voltage of the capacitor 26b is When the voltage exceeds the first voltage V1, the LF receiving unit 22 is switched to the standby state through the switching unit. Further, when the changeover switch 29 is turned on, the electronic key control unit 21 supplies power to itself from the capacitor 26b, and when the voltage of the capacitor 26b falls below the first voltage V1, the switching unit 28 The LF receiver 22 is switched to a non-standby state through On the other hand, when the changeover switch 29 is turned off, the electronic key control unit 21 switches the LF reception unit 22 to the non-standby state through the switching unit 28 regardless of the power supply source to itself and the voltage value thereof.

  Note that the electronic key control unit 21 monitors the voltage of the capacitor 26b when power is supplied from the capacitor 26b regardless of whether the changeover switch 29 is on or off. When the voltage of the capacitor 26b has reached the second voltage V2, the wireless signal Swi is generated when the lock switch 24 or the unlock switch 25 is operated. On the other hand, when the voltage of the capacitor 26b does not reach the second voltage V2, the wireless signal Swi is not generated even when the lock switch 24 or the unlock switch 25 is operated.

<Operation of electronic key system>
First, a case where the door lock device 14 is operated using the smart communication function will be described. First, a case where power is supplied to the electronic key control unit 21 from the battery 26a will be described. It is assumed that the changeover switch 29 is turned on.

  In this case, when the user holds the electronic key 20 and the user approaches the vehicle 10, smart communication is automatically performed between the vehicle 10 and the electronic key 20. Then, when the user touches the door handle sensor 15 provided on the door handle of the vehicle 10, the door lock device 14 is activated.

Next, a case where power is supplied to the electronic key control unit 21 from the capacitor 26b will be described. It is assumed that the changeover switch 29 is turned on.
The electronic key control unit 21 determines whether or not the voltage of the capacitor 26b exceeds the first voltage V1 based on the previous monitoring result. As shown in FIG. 2, when the voltage of the capacitor 26b is lower than the first voltage V1, the electronic key control unit 21 switches the LF reception unit 22 to the non-standby state through the switching unit 28. Thus, the electronic key control unit 21 does not receive a request signal transmitted from the vehicle 10, for example, the wake signal Swk. Therefore, the electronic key control unit 21 does not transmit the ACK signal Sac as a response to the wake signal Swk. That is, smart communication is not started between the electronic key 20 and the vehicle 10.

  Note that while the smart communication is disabled, power generation in the solar panel 27 is possible. The smart communication is disabled when the voltage of the capacitor 26b is lower than the first voltage V1. The first voltage V1 is lower than the second voltage V2. Therefore, when smart communication is impossible, wireless communication is also impossible. For this reason, in order to operate the door lock apparatus 14 using the wireless communication between the electronic key 20 and the vehicle 10, it is necessary to increase the storage amount of the capacitor 26b. That is, the user causes the solar panel 27 of the electronic key 20 to emit light. As a result, the solar panel 27 generates power and sends the electricity obtained by the power generation to the capacitor 26b. Then, after time T1 in FIG. 2, the voltage of the capacitor 26b gradually increases.

  As shown in FIG. 2, when the voltage of the capacitor 26b exceeds the first voltage V1 (time T1), the electronic key control unit 21 switches the LF reception unit 22 to the standby state through the switching unit 28. Thereby, the electronic key control unit 21 can receive a request signal transmitted from the vehicle 10. That is, the electronic key control unit 21 can start smart communication with the vehicle 10. When the electronic key control unit 21 receives the wake signal Swk from the vehicle 10 when the voltage of the capacitor 26b exceeds the first voltage V1, the electronic key control unit 21 transmits an ack signal Sac as a response thereto. Thereafter, when receiving the vehicle signal Svi from the vehicle 10, the electronic key control unit 21 transmits an ACK signal Sac as a response thereto. After that, when receiving the challenge signal Sch from the vehicle 10, the electronic key control unit 21 transmits a response signal Sre as a response to the challenge signal Sch. Thus, smart communication between the vehicle 10 and the electronic key 20 is performed.

  The electronic key control unit 21 consumes the power of the capacitor 26b and transmits a response signal, that is, an ACK signal Sac and a response signal Sre. For this reason, whenever the ACK signal Sac and the response signal Sre are transmitted, the voltage of the capacitor 26b decreases. Here, when the ACK signal Sac for the vehicle signal Svi is transmitted, that is, at the time T2 in FIG. 2, the voltage of the capacitor 26b falls below the first voltage V1.

  On the other hand, at time T <b> 2, the electronic key control unit 21 is in the middle of smart communication with the vehicle 10. For this reason, when the LF receiver 22 is switched to the non-standby state at time T2, the challenge signal Sch from the vehicle 10 cannot be received. Therefore, once the electronic key control unit 21 of the present example reaches the first voltage V1, the electronic key control unit 21 maintains the standby state in the LF reception unit 22 until a series of smart communication is completed. However, between time T2 and time T3, when the received radio signal is other than the challenge signal Sch, that is, the wake signal Swk or the vehicle signal Svi, the electronic key control unit 21 transmits a response signal to this signal. do not do. In other words, the electronic key control unit 21 executes only the ongoing smart communication after time T2, and does not start a new smart communication. By doing in this way, it can suppress that the capacitor | condenser 26b is consumed during smart communication and the said smart communication becomes impossible. The electronic key control unit 21 switches the LF reception unit 22 to the non-standby state through the switching unit 28 at time T3 when the transmission of the response signal Sre ends. Thereby, since the electronic key control part 21 does not receive the request signal from the vehicle 10, the electric power of the capacitor | condenser 26b is not consumed. Accordingly, since the electricity generated by the solar panel 27 is supplied to the capacitor 26b after time T3, the voltage of the capacitor 26b gradually increases.

  Next, a case where the door lock device 14 is operated using the wireless communication function will be described. First, a case where power is supplied to the electronic key control unit 21 from the battery 26a will be described. It is assumed that the changeover switch 29 is turned on.

  When the user operates the lock switch 24 or the unlock switch 25 and receives an electrical signal indicating that, the electronic key control unit 21 consumes the power of the battery 26a and stores the ID code stored in the memory 21a. And a wireless signal Swi that includes the operation content indicating that the vehicle door is locked or unlocked. Then, the generated wireless signal Swi is transmitted through the UHF transmission unit 23. When the in-vehicle control unit 11 receives the wireless signal Swi through the UHF receiving unit 13, it determines whether the ID code included in the wireless signal Swi corresponds to itself. And when it judges that it corresponds to self, the door lock apparatus 14 is operated based on the operation content similarly contained in the wireless signal Swi.

Next, a case where power is supplied to the electronic key control unit 21 from the capacitor 26b will be described. It is assumed that the changeover switch 29 is turned on.
The electronic key control unit 21 determines whether or not the voltage of the capacitor 26b has reached the second voltage V2 based on the previous monitoring result. As shown in FIG. 3, when the voltage of the capacitor 26b is lower than the second voltage V2, the electronic key control unit 21 does not generate the wireless signal Swi even when the lock switch 24 or the unlock switch 25 is operated. Thereby, since no wireless signal is transmitted from the electronic key 20, wireless communication is not performed between the electronic key 20 and the vehicle 10. At this time, the user performs charging by the solar panel 27. Accordingly, the voltage of the capacitor 26b gradually increases.

  As shown in FIG. 3, the electronic key control unit 21 can transmit the wireless signal Swi by consuming the power of the capacitor 26b after time T4 when the voltage of the capacitor 26b reaches the second voltage V2. After this time T4, when the lock switch 24 or the unlock switch 25 is operated and an electric signal indicating that is inputted (time T5), the electronic key control unit 21 consumes the power of the capacitor 26b, Wireless signal Swi is generated. Then, the generated wireless signal Swi is transmitted through the UHF transmission unit 23. When the in-vehicle control unit 11 receives the wireless signal Swi through the UHF receiving unit 13, it determines whether the ID code included in the wireless signal Swi corresponds to itself. And when it judges that it corresponds to self, the door lock apparatus 14 is operated based on the operation content similarly contained in the wireless signal Swi. Note that the amount of electricity stored in the capacitor 26b is such that the wireless signal Swi can be transmitted once. For this reason, the amount of power stored in the capacitor 26b is depleted at time T6 when the electronic key control unit 21 finishes transmitting the wireless signal Swi. Since time T6, electricity generated by the solar panel 27 is supplied to the capacitor 26b, so that the voltage of the capacitor 26b gradually increases.

  The electronic key 20 of this example is provided with a changeover switch 29 for switching on / off of the smart communication function. When the changeover switch 29 is turned off, the electronic key control unit 21 switches the LF reception unit 22 to the non-standby state through the switching unit 28. For this reason, when it is desired to operate the door lock device 14 using the wireless communication function, the smart switch is not performed between the electronic key 20 and the vehicle 10 if the changeover switch 29 is turned off. In other words, before the voltage of the capacitor 26b becomes the second voltage V2, the electronic key control unit 21 does not consume the power of the capacitor 26b and perform smart communication with the vehicle 10. Thereby, before the voltage of the capacitor | condenser 26b becomes 2nd voltage V2, smart communication is repeated and the situation which cannot perform wireless communication can be prevented.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) When the voltage of the capacitor 26b that supplies driving power to the electronic key 20 is lower than the first voltage V1, which is a reference value that can complete smart communication, a request signal from the vehicle 10, accurately Stops receiving the wake signal Swk. Thereby, the electronic key 20 does not transmit the ACK signal Sac as a response to the wake signal Swk. For this reason, transmission of a radio signal during charging is suppressed. When the voltage of the capacitor 26b reaches the first voltage V1 by charging through the solar panel 27, the electronic key 20 is ready to receive a request signal. Thereby, the user can perform smart communication between the vehicle 10 and the electronic key 20 and can operate the door lock device 14 of the vehicle 10.

  (2) When the voltage of the capacitor 26b is lower than the second voltage V2, which is a reference value necessary for transmission of the wireless signal Swi, even if the lock switch 24 or the unlock switch 25 is operated, the wireless signal Swi The transmission was not performed. The wireless signal Swi can be transmitted when the total amount of charging of the capacitor 26b by the solar panel 27 exceeds the amount of power required for the wireless signal Swi. Also in this case, the wireless signal Swi is not transmitted during charging. Therefore, the wireless signal Swi is transmitted with sufficient power. Since the transmission of the wireless signal Swi is not interrupted on the way, the door lock device 14 of the vehicle 10 can be operated.

  (3) The amount of electric power that can be stored in the capacitor 26b is an amount that can transmit the wireless signal Swi once. With this configuration, the time required for the charging to be completed is shorter than when the amount of power that can be stored in the capacitor 26b is larger than the amount of transmission of the wireless signal Swi once. Therefore, even when the capacitor 26b is consumed, wireless communication can be used in a short time.

  (4) The electronic key control unit 21 consumes the power of the battery 26a only when the capacitor 26b is exhausted and transmits a radio signal. As a result, the power consumption of the battery 26a is suppressed, and the life of the battery 26a is shortened.

In addition, you may change the said embodiment as follows.
In the above embodiment, power storage means other than the capacitor 26b may be employed. For example, there are secondary batteries. Even when these are used, the same effect as the above-described embodiment can be obtained.

  -In the said embodiment, you may employ | adopt power generation means other than a solar panel. For example, there are a piezoelectric element, electromagnetic induction using a magnet and a coil, and the like. Even when these are used, the same effect as the above-described embodiment can be obtained. In addition, if these are utilized, it is also possible to generate electric power using vibration during walking of the user or vibration obtained by intentionally shaking the electronic key 20.

  In the above-described embodiment, the power supply unit 26 may be configured only by the power storage unit. In this case, the voltage threshold value of the power supply unit 26 serving as a criterion for determining whether or not the electronic key control unit 21 stops receiving the request signal from the vehicle 10 may be set to a value at which at least one wireless signal can be transmitted. Even if it does in this way, the effect similar to the said embodiment can be acquired.

  In the above embodiment, the electronic key 20 can perform both smart communication and wireless communication with the vehicle 10, but may be configured to perform only one of them. When only smart communication is performed, the capacitor 26b may be fully charged as the first voltage V1.

  In the above embodiment, the changeover switch 29 that switches the LF reception unit 22 to the non-standby state through the switching unit 28 is provided, but the switch 29 may not be provided. Even in the case of such a configuration, it is possible to obtain the same effect as the above embodiment.

  In the above embodiment, when the voltage of the capacitor 26b is lower than the first voltage V1, the electronic key control unit 21 switches the LF reception unit 22 to the non-standby state through the switching unit 28, but remains in the standby state. May be. In this case, the electronic key control unit 21 does not have to transmit response signals (ac signal Sac, response signal Sre) to the request signals (wake signal Swk, vehicle signal Svi, challenge signal Sch) from the vehicle 10. Even in the case of such a configuration, it is possible to obtain the same effect as the above embodiment.

  In the above embodiment, the request signals are the three signals of the wake signal Swk, the vehicle signal Svi, and the challenge signal Sch. However, these signals may be combined into one or two signals. . In this case, the response signal of the electronic key 20 is also one or two signals. Even in such an intercommunication mode, the same effect as in the above embodiment can be obtained.

  In the above embodiment, the electronic key control unit 21 consumes the power of the battery 26a and transmits a radio signal only when the capacitor 26b is exhausted, but conversely, the battery 26a is exhausted. Sometimes the capacitor 26b is charged, and the radio signal is transmitted by consuming the power of the capacitor 26b. In this case, even if the battery 26a cannot be replaced immediately, wireless communication between the electronic key 20 and the vehicle 10 can be performed.

  In the above embodiment, the electronic key 20 is not limited to communicating with the vehicle 10. For example, the house etc. which communicate with the electronic key 20 may be sufficient. Even if comprised in this way, the effect similar to the said embodiment can be acquired.

DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 10 ... Vehicle, 11 ... Vehicle-mounted control part as control means, 11a ... Memory, 12 ... LF transmission part, 13 ... UHF receiving part, 14 ... Door lock device, 15 ... Door handle sensor, 20 ... Electronic key, 21 ... Electronic key controller, 21a ... Memory, 22 ... LF receiver, 23 ... UHF transmitter, 24 ... Lock switch, 25 ... Unlock switch, 26 ... Power supply unit, 26a ... Battery, 26b ... Condenser, 27 ... Solar panel, 28 ... switch, 29 ... switch.

Claims (6)

A power generation means, a power storage means that can be charged by electricity generated by the power generation means, and a control means that consumes power of the power storage means and exchanges radio signals with the communication master, The control means is an electronic key for operating or permitting operation of various electronic devices mounted on the communication master through transmission and reception of wireless signals.
The control means prohibits transmission of the wireless signal when the amount of electricity stored in the electricity storage means is below a power threshold necessary to complete transmission of the wireless signal, and the amount of electricity stored in the electricity storage means is reduced by the charging. An electronic key that permits the start of transmission of the radio signal when the power threshold is reached. The electronic key according to claim 1, wherein
The amount that can be stored by the storage means is an electronic key that is a power threshold. The electronic key according to claim 1 or 2,
It has a switch that can be operated from the outside,
The control means uses an electronic key for consuming the power of the power storage means to transmit the wireless signal to the communication master and operating the electronic device through transmission of the wireless signal, triggered by the operation of the switch . In the electronic key as described in any one of Claims 1-3,
The control means, triggered by reception of a wireless signal requesting a response from the communication master, consumes the power of the power storage means and transmits a wireless signal as a response to the wireless signal. An electronic key for operating or permitting operation of the electronic device through exchange. The electronic key according to claim 4, wherein
An electronic key that does not receive a radio signal from the communication master when a power storage amount of the power storage means is below the power threshold. In the electronic key as described in any one of Claims 1-5,
In addition to the power storage means, an electronic key including a replaceable primary battery and transmitting the radio signal by consuming the power of the primary battery.

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