JP5410892B2 - Electronic key system and power supply method for electronic key - Google Patents

Description

  The present invention relates to an electronic key system that uses an electronic key as a vehicle key and a power supply method for the electronic key.

  2. Description of the Related Art Recently, in vehicle key systems, electronic key systems that perform ID verification by wirelessly transmitting an ID code as a key code from an electronic key as a vehicle key have been adopted in various vehicle types. In this electronic key system, a request communication area is formed around the vehicle by an LF band signal as an ID code return request, and when the electronic key enters the communication area and receives the request, the electronic key transmits the ID code to the RF code. Reply to vehicle with band signal. When the vehicle receives the ID code, the vehicle performs ID verification. If the ID verification is established, the vehicle permits or executes door lock / unlock and engine start (see, for example, Patent Document 1).

  In this electronic key system, a request is periodically transmitted from the vehicle, the electronic key receives the request outside the vehicle, and the vehicle performs ID verification (verification outside the vehicle) with an ID code returned in response to the request. Run. The vehicle permits or executes door lock / unlock when the vehicle outside verification is established. In the electronic key system, the electronic key receives the ID code in the vehicle, and the vehicle performs ID verification (in-vehicle verification) with the ID code returned by the electronic key in response to the request. The vehicle permits or executes the start of the engine when the in-vehicle verification is established.

  Since the electronic key operates using a battery as a power source, when the battery voltage reaches the limit operating voltage with the passage of the use year (number of times of use), ID collation cannot be performed. As a guide, the battery can be used for over a year without replacement. Therefore, in preparation for the battery running out of the electronic key, a mechanical key is accommodated in the electronic key, and the door lock and unlocking when the battery runs out is handled by using the mechanical key. Furthermore, a transponder is built in the electronic key, and engine start when the battery runs out is handled by bringing the electronic key closer to the coil antenna in the vehicle and establishing ID verification by the transponder.

JP 2002-29385 A

  However, even when the electronic key is equipped with a mechanical key or a transponder to take measures against running out of the battery, it is rare that the electronic key runs out of battery. For this reason, when the battery actually runs out, it can be dealt with by using a mechanical key or transponder, but the user can actually operate the vehicle even if he has an electronic key. There was a current situation where we faced a situation where we couldn't be confused by facing a situation where we couldn't. Therefore, there has been a demand for a new technology that does not cause the user to be in a confused state caused by the fact that the electronic key falls out of battery.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an electronic key system and an electronic key power supply method that can make it difficult for a user to be confused by running out of batteries. It is in.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
The invention according to claim 1 is a smart communication in which an electronic key transmits an ID code in response to a reply request for an ID code transmitted from a communication target and performs ID collation, and operation means provided in the electronic key. In an electronic key system capable of both communication with wireless communication that enables operation of a device installed in the communication target on the condition that ID verification of the ID code transmitted by the operation is established, the communication target A power transmission means for transmitting a power radio wave as a power source at the time of smart communication of the electronic key from the power transmission device installed in the communication target during the smart communication; provided in the electronic key; Charging execution means for acquiring the power radio wave emitted from the power transmission device during communication and charging a charging unit mounted on the electronic key; Wherein provided in the electronic key, when the electronic key to perform the wireless communication, and a power supply switching means for operating the electronic key the charging unit as a power supply, the electronic key is the communication target in the smart communication The gist of the response signal returned to is that it is transmitted by the reflected radio wave that returns the electric power radio wave .

According to this configuration, when the electronic key performs smart communication with the communication target, power radio waves are transmitted from the power transmission device to be communicated, and the electronic key is caused to execute smart communication using the power radio waves as a power source. In addition, when the electric key is transmitted to the charging unit of the electronic key during the smart communication and the electronic key performs wireless communication, the electronic key is caused to execute wireless communication using the charging unit as a power source. As described above, both communications can be executed without having to use a separate battery for the electronic key, so it is not necessary to assume a situation where the electronic key runs out of battery, and the user is not in a troubled state due to running out of battery. That's it. Further, the radio signal transmitted from the electronic key to the communication target is a reflected radio wave using the electric power radio wave received by the electronic key. For this reason, it is not necessary to provide a transmission means for newly transmitting a radio signal, and it is possible to efficiently transmit a radio signal to a communication target using power radio waves.

  According to a second aspect of the present invention, in the electronic key system according to the first aspect, after the verification of the smart communication is established, the transmission of the electric power radio wave from the power transmission device is performed for a predetermined time. A power radio wave transmission continuation unit that continues between the power transmission device and the charging execution unit obtains the power radio wave from the power transmission device after the verification of the smart communication is established and executes charging to the charging unit. It is a summary.

  According to this configuration, after the smart communication verification is established, the charging unit of the electronic key is charged by the electric power radio wave received from the power transmission device. For this reason, it is possible to use power radio waves obtained from the power transmission device as the power source of the electronic key separately in time series for the smart communication power source and the charging unit charging, so that sufficient power is supplied to both can do. Further, since it is not necessary to perform these two processes at the same time, the power control can be facilitated.

  According to a third aspect of the present invention, in the electronic key system according to the first or second aspect, the charging request is provided as the request for the electronic key to start charging the charging unit. The gist of the present invention includes charging request transmitting means for transmitting from the transmission device to the electronic key, and the charging execution means executes charging to the charging unit upon receiving the charging request from the power transmission device. Yes.

  According to this configuration, since the charging execution unit starts charging the charging unit triggered by receiving a charging request from the power transmission device, charging is performed at a suitable timing of receiving an instruction to start charging from a communication target. It becomes possible to start. For this reason, it is possible to grasp when the electronic key is to be charged and accurately charge the electric power radio wave transmitted from the communication target.

  According to a fourth aspect of the present invention, in the electronic key system according to the third aspect of the present invention, the electronic key system includes a determination unit that is provided in the communication target and determines whether a charging voltage of the charging unit is less than a threshold value. The charging request transmission unit transmits the charging request to the electronic key to cause the electronic key to start charging the charging unit when the determination unit determines that the charging voltage of the charging unit is less than a threshold value. That is the gist.

  According to this configuration, when the communication target recognizes that the charging voltage of the electronic key is less than the threshold, the communication target transmits a charging request to the electronic key, and the electronic key is charged by receiving the charging request as a trigger. Start charging the unit. For this reason, it is possible to execute charging to the charging unit when charging to the charging unit is really necessary, so the charging operation is executed even though the remaining charging amount of the charging unit remains. It is not necessary to execute a useless process such as that.

  According to a fifth aspect of the present invention, in the electronic key system according to any one of the first to fourth aspects, the charging unit can store power sufficient for the electronic key to perform at least wireless communication. Its gist is that it is a capacitor.

  According to the same configuration, a capacitor was used as the charging unit, but unlike a secondary battery, this type of capacitor does not involve an electrochemical reaction, so there is no limit on the number of charging / discharging, and the internal resistance is low and charging / discharging in a short time. Can be done.

The invention according to claim 6 is transmitted by the smart communication which transmits the ID code in response to the ID code reply request transmitted from the communication object and performs ID collation and the operation on the operation means provided in itself. In addition, in the electronic key power supply method capable of performing both communication with the wireless communication that enables operation of the device installed on the communication target on the condition that ID verification of the ID code is established, the electronic code is installed on the communication target. The power radio wave transmitted from the power transmission device is used as a power source during smart communication of the electronic key, and the power radio wave emitted from the power transmission device during the smart communication is acquired and mounted on the electronic key. was charged to the charging unit, when performing the wireless communication, the charging unit and power supply, the response signal the electronic key during the smart communication is returned to the communication target , And its gist that originated by reflecting radio waves back to the power wave.

  ADVANTAGE OF THE INVENTION According to this invention, the power supply method of the electronic key system and electronic key which can be made hard to fall into the state where a user is confused by battery exhaustion can be provided.

The block diagram which shows schematic structure of an electronic key system. The schematic block diagram which shows the electric power supply by the side of the electronic key at the time of smart communication. The schematic block diagram which shows the electric power wireless supply by the side of the electronic key at the time of charge. The time chart which shows operation | movement with the electronic key at the time of ID collation, and a vehicle. The schematic block diagram which shows the electric power supply by the side of the electronic key at the time of wireless communication. The sequence chart which shows the communication operation | movement at the time of wireless communication. The sequence chart which shows the communication operation at the time of ID collation.

Hereinafter, an embodiment in which an electronic key system according to the present invention is embodied in a vehicle will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 2 is equipped with an electronic key system that uses the electronic key 1 as a vehicle key and wirelessly transmits the ID code of the electronic key 1 to the vehicle 2 to perform ID verification. Yes. In this electronic key system, for example, there is a key operation-free system that can perform vehicle operations such as locking / unlocking of door locks and starting / stopping of an engine without the driver actually operating the vehicle key. included. The electronic key system also includes a wireless key system for operating the in-vehicle device by remote operation by button operation on the electronic key 1.

  The electronic key system includes a power transmission system that transmits a radio wave (hereinafter referred to as a power radio wave Svv) serving as a power source for the electronic key 1 from the vehicle 2 to the electronic key 1 and operates the electronic key 1 using the power radio wave Svv. It has been. The electronic key system of this example is a power transmission type in which the power of the electronic key 1 at the time of so-called smart communication is provided by the power radio wave Svv from the vehicle 2 in the communication of the key operation free system. And the electronic key system of this example carries out narrow area | region radio | wireless communication (smart communication) between the electronic key 1 and the vehicle 2, putting information on the electric power radio wave Svv of this electric power transmission system.

  The vehicle 2 is provided with a verification ECU (Electronic Control Unit) 21 that performs ID verification when performing narrow-area wireless communication with the electronic key 1, and a main body ECU 31 that manages the operation of an in-vehicle motor, a relay, and the like. It has been. The verification ECU 21 includes a vehicle exterior transmitter 22 as a power transmission device embedded in each door of the vehicle 2 and capable of transmitting radio waves in the RF (Radio Frequency) band outside the vehicle, and an RF band embedded in the vehicle under the vehicle floor. An in-vehicle transmitter 23 serving as a power transmission device capable of transmitting the above-mentioned radio wave is connected to an RF receiver 24 that is embedded in a vehicle body or the like behind the vehicle and that can receive an RF band radio wave. These outside transmitter 22 and in-vehicle transmitter 23 can transmit both the radio wave (hereinafter referred to as request signal Srq) according to the electronic key system and the above-described power radio wave Svv.

  In addition, the verification ECU 21 is provided with a transmission control unit 21b as power transmission means for managing the transmission operation of the outside transmitter 22 and the inside transmitter 23. The transmission control unit 21b periodically transmits the request signal Srq and the electric power radio wave Svv from the vehicle transmitter 22 and the vehicle transmitter 23 during smart communication.

  For example, a main body ECU 31 that manages door lock locking / unlocking and the like is connected to the verification ECU 21 via an in-vehicle LAN (Local Area Network) 30. For example, a door lock device 38 made of an electric lock is connected to the main body ECU 31.

  When the verification ECU 21 confirms that ID verification (external verification) is established by the ID code signal Sid returned from the electronic key 1 when the request signal Srq is transmitted from the external transmitter 22, the verification ECU 21 unlocks and unlocks the door lock. To give permission. And in this permission state, when the touch sensor 28 of the vehicle exterior door handle 27 as an operation means is touch-operated, the verification ECU 21 drives the door lock device 38 to unlock the door lock. On the other hand, the verification ECU 21 drives the door lock device 38 to lock the door lock when the lock button 29 of the door handle 27 outside the vehicle is pressed.

  In addition, the vehicle 2 is provided with an engine ECU 32 that performs engine ignition control and fuel injection control based on the ID verification establishment result of the verification ECU 21. The engine ECU 32 is connected to various ECUs such as the verification ECU 21 through the in-vehicle LAN 30. The driver's seat of the vehicle 2 is provided with an engine switch 33 that is operated when switching the power supply state (power supply position) of the vehicle 2. Each time the engine switch 33 is pushed, the power state is repeatedly changed in the order of ACC on → IG on → power off. When the engine is operated with the brake pedal depressed when the engine is stopped, the engine is switched to start. .

  The verification ECU 21 transmits a request signal Srq from the in-vehicle transmitter 23 when, for example, the courtesy switch 37 recognizes that the door is opened and the driver has boarded after the outside verification is established and the door lock is unlocked. ID collation (in-vehicle collation) is performed. When the verification ECU 21 confirms that the in-vehicle verification is established, the verification ECU 21 permits switching of the power state by the engine switch 33.

  On the other hand, the electronic key 1 is provided with a communication control unit 11 as a control unit for performing wireless communication with the vehicle 2 according to the electronic key system. The communication control unit 11 includes a memory 11a in which an ID code is stored as a unique key code. The communication control unit 11 is connected to a key transmission / reception unit 12 that transmits and receives RF radio waves during smart communication. The key transmission / reception unit 12 is provided with a reception circuit 12b as a circuit that satisfies the reception function in the key transmission / reception unit 12. The receiving circuit 12b is a circuit that demodulates or amplifies the received radio wave. The reception circuit 12b is provided with a rectifier circuit 12c that converts the electric power radio wave Svv received from the vehicle 2 into a direct current and supplies it to the communication control unit 11. The rectifier circuit 12c supplies the rectified power (wireless power Jw) as a power source to the electronic key 1 (the communication control unit 11 and the key transmission / reception unit 12).

  The key transmission / reception unit 12 is provided with a transmission circuit 12a as a circuit that satisfies the transmission function in the key transmission / reception unit 12. The transmission circuit 12a is of a radio wave reflection type (passive type) in which the electric power radio wave Svv received from the electronic key 1 is directly converted into a signal of “0” or “1” to transmit the radio wave. That is, the transmission circuit 12a modulates the received power radio wave Svv to generate, for example, “1”, and does not reflect the power radio wave Svv, for example, generates “0”. Reply.

  The communication control unit 11 is connected to an RF transmission unit 15 capable of transmitting an RF band radio wave in accordance with a command from the communication control unit 11. The RF transmission unit 15 modulates communication data obtained from the communication control unit 11 and generates a transmission radio wave. The RF transmitter 15 transmits RF radio waves, that is, wireless signals (lock signal S1, unlock signal) in response to button operations (lock button 17 and unlock button 18) with the electronic key 1 during wireless key system communication, so-called wireless communication. The lock signal (Sul) can be transmitted.

  As shown in FIG. 1 to FIG. 3, the power transmission system of this example is provided with a charging function for charging the capacitor 14 as a charging unit mounted on the electronic key 1 as a unique power source with the electric power radio wave Svv. Yes. In the power transmission system of this example, the power of the electronic key 1 at the time of smart communication is supplied by the electric power radio wave Svv. This is a system for charging with electric power radio waves Svv.

  The capacitor 14 is connected to both the communication control unit 11 and the key transmission / reception unit 12 (rectifier circuit 12c) via the switching unit 13. For example, an electric double layer capacitor is used as the capacitor 14. An electric double layer capacitor has a low internal resistance and can be charged / discharged in a short time, and has a long life because there is no deterioration due to charging / discharging. In addition, the electric double layer capacitor has a larger capacity than other capacitors, and a large amount of electric power is required for wireless communication, but this electric power can be provided.

  The switching unit 13 is connected between the communication control unit 11 and the receiving circuit 12b and the capacitor 14, and based on a command from the communication control unit 11, the power source of the electronic key 1 (communication control unit 11) is switched to the capacitor 14 and the power radio wave Svv. It is a switch to switch to either. Specifically, as shown in FIGS. 2, 3, and 5, the switching unit 13 includes a power switch 13 a that switches the power source of the communication control unit 11 and the like to one of the rectifier circuit 12 c and the capacitor 14, and a rectifier circuit. 12c and the charge switch 13b which turns on and off the connection of the capacitor | condenser 14 are provided. The power switch 13a of the switching unit 13 is normally connected to the rectifier circuit 12c side and operates the electronic key 1 using the wireless power Jw as a power source. The charging switch 13b of the switching unit 13 is normally in an OFF state and can be switched to an ON state by a command from the communication control unit 11. The power switch 13a functions as power switching means.

  Further, the communication control unit 11 is provided with a power source selection unit 11c as a power source switching unit that sets the power source of the electronic key 1 to one of the wireless power Jw and the charging power Jc. The power selection unit 11c of this example normally connects the power switch 13a to the rectifier circuit 12c side and supplies the wireless power Jw as a power source for the electronic key 1. Further, the power selection unit 11c connects the power switch 13a to the capacitor 14 side when the lock button 17 or the unlock button 18 is pressed, that is, when the start operation of the wireless communication is performed in the electronic key 1. The charging power Jc is supplied as a power source for the electronic key 1.

  The communication control unit 11 is provided with a charge control unit 11b as charge execution means for controlling the operation of the switching unit 13. The charge controller 11b periodically acquires the voltage value of the capacitor 14, and transmits the ID code signal Sid including the capacitor voltage information when transmitting the ID code signal Sid. Here, the capacitor voltage information is a 1-bit code indicated by “0” when the threshold voltage is necessary for the operation of the electronic key 1, that is, not less than the limit operating voltage, and “1” when it is less than the limit operating voltage. It is. The capacitor voltage functions as the charging voltage.

  On the other hand, the verification ECU 21 is provided with a charge execution unit 21c as power radio wave transmission continuation means for managing charging of the capacitor 14 on the vehicle 2 side. After the smart verification is established, the charging execution unit 21c checks the capacitor voltage based on the capacitor voltage information acquired during the communication, and confirms that the capacitor voltage is less than the limit operating voltage. Recognizing that it cannot be performed by the capacitor 14, after the smart communication is completed, the transmission operation of the electric power radio wave Svv by the external transmitter 22 (in-vehicle transmitter 23) is continued and supplied to charge the capacitor 14.

Next, the operation of the key operation free system of this example will be described with reference to FIGS.
First, operations during smart communication will be described with reference to FIGS. At this time, as shown in FIG. 2, the electronic key 1 is connected to the rectifier circuit 12c side and the charging switch 13b is turned off as shown in FIG. Smart mode). Therefore, the electronic key 1 acquires the power radio wave Svv received from the vehicle 2 as a power source, and operates with the power radio wave Svv without using the power of the capacitor 14 that the electronic key 1 has.

  As shown in FIG. 4, when performing smart communication with the electronic key 1 during parking, the verification ECU 21 first starts the electronic key 1 that is in a stopped state (sleep state) to activate the wake power radio wave Svw. Is transmitted from the transmitter 22 outside the vehicle. The wake power radio wave Svw is a radio wave including the wake code Swk for activating the communication control unit 11 and the power radio wave Svv. The wake power radio wave Svw is repeatedly transmitted from the vehicle transmitter 22 at regular intervals, and the presence or absence of the electronic key 1 around the vehicle 2 is monitored. The wake power radio wave Svw is transmitted until the time when the electronic key 1 will complete the transmission operation so that the transmission operation of the electronic key 1 can be covered by the power radio wave Svv.

  When the electronic key 1 enters the outside communication area of the wake power radio wave Svw, since the electronic key 1 is set to the wireless power source mode at this time, the electronic key 1 uses the received radio power Jw as a power source and uses the wake power radio wave Svw. The wake code Swk included in is received. The key transmitting / receiving unit 12 determines whether the wake code Swk is correct or not, and switches the communication control unit 11 from the sleep state to the activated state if the wake code Swk is normal. When the communication control unit 11 is switched to the activated state, the communication control unit 11 transmits an ACK signal Sac from the key transmission / reception unit 12 by a reflected radio wave.

  When the vehicle 2 receives the ACK signal Sac within a predetermined time after transmitting the wake power radio wave Svw, the vehicle 2 recognizes that the electronic key 1 exists in the outside communication area and continues the smart communication. At this time, the transmission control unit 21b continues to transmit the electric power radio wave Svv from the vehicle transmitter 22, and continues to supply the electric key 1 to the electronic key 1 until the smart communication is terminated using the electronic key 1 as a power source.

  When the verification ECU 21 receives the ACK signal Sac as a response to the wake power radio wave Svw, the verification ECU 21 continuously transmits the power radio wave Svv and transmits the vehicle ID signal Svi from the outside transmitter 22. The vehicle ID signal Svi includes a vehicle ID as a vehicle-specific ID for identifying the vehicle 2. The electronic key 1 that has received the vehicle ID signal Svi performs vehicle ID verification against the code registered in the memory 11a. If the verification matches, the electronic key 1 transmits an ACK signal Sac from the key transmission / reception unit 12 by reflected radio waves.

  When the vehicle 2 receives the ACK signal Sac within a predetermined time after transmitting the vehicle ID signal Svi, the vehicle 2 recognizes that the electronic key 1 corresponding to the vehicle 2 exists in the outside communication area, and this time the challenge signal Scc is sent to the outside transmitter. Call from 22. The challenge signal Scc includes a challenge code whose value changes each time a call is made and the key number of the electronic key 1. Note that the key number is a notification of what number master key or what number sub key.

  When the key transmission / reception unit 12 receives the challenge signal Scc, the communication control unit 11 of the electronic key 1 performs number verification to check whether the key number of the challenge signal Scc is correct, and whether or not the communication control unit 11 itself is a communication partner at this time. Determine whether. This number verification is verification for determining the master or sub key type for the electronic key 1 of the communication partner. When this number verification is established, the communication control unit 11 generates a response code by calculating a challenge code included in the challenge signal Scc with its own encryption key. When the generation of the response code is completed, the communication control unit 11 causes the key transmission / reception unit 12 to transmit a response signal Sre including the ID code registered in its own memory 11a and the response code by the reflected radio wave. Note that the arrangement order of the ID code and the response code in the response signal Sre can be changed as appropriate.

  Further, when transmitting the response signal Sre to the vehicle 2, the charging control unit 11b transmits the response signal Sre including capacitor voltage information. This capacitor voltage information represents the capacitor voltage at the time of collation by bits. Therefore, the charging control unit 11b notifies the vehicle 2 of the capacitor voltage information at the same time when returning a challenge response authentication response to the vehicle 2.

  When transmitting the challenge signal Scc, the verification ECU 21 calculates a challenge code using its own encryption key and generates a response code itself. When the verification ECU 21 receives the response signal Sre from the electronic key 1 by the RF receiver 24, the verification ECU 21 compares the response code of the electronic key 1 with the response code calculated by itself, and executes response verification. When the verification ECU 21 confirms that this response verification is established, the verification ECU 21 verifies whether the ID code included in the response signal Sre is correct. And if collation ECU21 confirms that response collation and ID code collation will be materialized, it will process smart collation as this by this.

  Further, when receiving the response signal Sre, the verification ECU 21 determines the capacitor voltage information included in the response signal Sre by the charge execution unit 21c as a determination unit. At this time, when the charging execution unit 21c confirms that the capacitor voltage is equal to or higher than the limit operating voltage, the charging execution unit 21c recognizes that wireless communication is possible using the capacitor 14 as a power source, and stops the transmission of the electric power radio wave Svv.

  On the other hand, if the capacitor voltage is less than the limit operating voltage, the charging execution unit 21c recognizes that wireless communication cannot be performed using the capacitor 14 as a power source. Then, the charging execution unit 21c sets a capacitor voltage drop flag in the memory 21a. Thereby, the charge execution part 21c transmits the charge request | requirement electric power electric wave Svk from the vehicle exterior transmitter 22 as a request | requirement which makes the electronic key 1 perform charge operation. The charge request power radio wave Svk includes the power radio wave Svv described above and a charge request signal Scd that instructs the electronic key 1 to start charging the capacitor 14. Thereby, the charging execution part 21c continues supplying the electric wave Svv to the electronic key 1 for a fixed time after smart communication. The charging execution unit 21c functions as a charging request transmission unit.

  When the charge request power radio wave Svk from the vehicle 2 is received by the key transmission / reception unit 12, the charge control unit 11b charges the electronic key 1 as shown in FIG. 3 using the charge request signal Scd included in the charge request power radio wave Svk. Switch to mode. This charging mode is a mode when the charging switch 13b is turned on while maintaining the state where the power switch 13a is connected to the rectifier circuit 12c side. As a result, the wireless power Jw flowing out from the rectifier circuit 12c reaches the capacitor 14, and the capacitor 14 is charged by the wireless power Jw for a certain period of time.

Here, the operation of the vehicle 2 and the electronic key 1 at the time of external verification has been described. However, since the same operation is performed at the time of internal verification, description of the internal verification is omitted.
Next, operations during wireless communication will be described with reference to FIGS. First, as shown in FIG. 6, the electronic key 1 is set to the wireless power supply mode in the normal state (step S21). That is, the power switch 13a is connected to the rectifier circuit 12c side, and the charging switch 13b is set to the OFF state.

  And the communication control part 11 will set to a capacitor | condenser power supply mode, if the locking button 17 or the unlocking button 18 is operated (step S22) (step S23). That is, as shown in FIG. 5, when the power selection unit 11c detects that these buttons for wireless communication have been operated, the power selection unit 11c switches the power switch 13a from the rectifier circuit 12c side to the capacitor 14 side. The electronic key 1 operates using the charging power Jc from the capacitor 14 as a power source. And as FIG. 6 shows, the communication control part 11 transmits the locking signal Sl or the unlocking signal Sul which included its own ID code from the RF transmission part 15 (step S24).

  The verification ECU 21 receives the locking signal S1 or the unlocking signal Sul by the RF receiver 24 to establish wireless communication (wireless communication), and uses the ID code registered in its own memory 21a and the ID code of the electronic key 1 ID verification (wireless verification) is performed in light of this. When the wireless verification is established (step S25), the verification ECU 21 outputs a door lock locking command or unlocking command to the main body ECU 31, and causes the door lock device 38 to lock or unlock the door lock (step S26). ).

  Now, in the electronic key system of this example, the electric wave Svv is transmitted from the vehicle 2 at the time of smart communication, and the electronic key is operated by using the power radio wave Svv as a power source. ). In addition, since the electric wave Svv received during smart communication is charged to the capacitor 14 of the electronic key and the electronic key is operated using the capacitor 14 as a power source during wireless communication, the electronic key 1 does not have its own individual power supply. Wireless communication can be executed. Thus, since the electronic key 1 of this example does not need to pay attention to power management, that is, battery replacement, the user does not have to be in a troubled state due to running out of batteries.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) The power required by the electronic key 1 during smart communication is covered by the electric power radio wave Svv. During the smart communication, the electric power radio wave Svv is charged to the capacitor 14 of the electronic key 1, and the capacitor 14 is used as a power source during wireless communication. The electronic key 1 is operated. For this reason, since it is not necessary to mount an individual power source such as a primary battery on the electronic key 1, battery management becomes unnecessary, and as a result, the user can be prevented from falling into a troubled state due to running out of battery. Further, the capacitor 14 is automatically charged with the power radio wave Svv of smart communication without the user being aware of it. By using the electric power radio wave Svv, the batteryless electronic key 1 and most of the antenna, circuit, etc. can be shared.

  (2) After the end of the smart communication, the transmission of the electric power radio wave Svv is continued and the capacitor 14 is charged. For this reason, the electric power radio wave Svv can be used separately for the smart communication power source and the capacitor 14 charging, and sufficient power can be supplied to both. Further, since it is not necessary to perform these two processes at the same time, the power control can be facilitated.

  (3) The charging request power radio wave Svk is transmitted from the vehicle 2 to the electronic key 1, and the charging of the capacitor 14 to the electronic key 1 is started by the charging request signal Scd. For this reason, since the electronic key 1 can grasp | ascertain the suitable timing which should be charged, it can charge the electric power radio wave Svv transmitted from the vehicle 2 exactly.

  (4) When the vehicle 2 recognizes that the capacitor voltage of the electronic key 1 is less than the limit operating voltage, the vehicle 2 transmits the charging request signal Scd to the electronic key 1 and receives the charging request signal Scd. Starts charging the capacitor 14. For this reason, the electronic key 1 can charge the capacitor 14 when the capacitor voltage of the electronic key 1 decreases and charging is necessary. Therefore, it is possible to grasp when to charge, and to charge accurately at a necessary timing.

  (5) The electronic key 1 charges the capacitor 14 with the wireless power Jw. Unlike the secondary battery, the capacitor 14 is not accompanied by an electrochemical reaction, so there is no limit on the number of charge / discharge cycles, and the internal resistance is low, so that charge / discharge can be performed in a short time. Since the electronic key 1 is required to be small, light, and have a long life, the capacitor 14 has many advantages as a power source used for wireless communication.

  (6) Various response signals (for example, ID code signal Sid) returned from the electronic key 1 to the vehicle 2 during smart communication are reflected radio waves that return the power radio wave Svv as it is with binary information of “0” or “1”. Called. For this reason, it is not necessary to provide a transmission means for newly transmitting a radio signal, and the radio signal can be transmitted to the vehicle 2 with lower power consumption than the oscillation type power consumption using the electric power radio wave Svv.

  (7) Since the request signal Srq and the electric power radio wave Svv can be transmitted from the same one outside transmitter 22 and in-vehicle transmitter 23, it is not necessary to prepare a separate transmitter for each radio wave and is installed in the vehicle 2. The number of parts to be reduced can be reduced.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, charging of the wireless power Jw to the capacitor 14 is performed after smart communication. However, it may be performed before smart communication. For example, as shown in FIG. 7, a case will be described in which the capacitor voltage acquired by the vehicle 2 during the previous smart communication is less than the limit operating voltage. The electronic key 1 is set to the wireless power supply mode (step S31). If the capacitor voltage is less than the limit operating voltage, the vehicle 2 transmits the electric power radio wave Svv carrying the charge request signal Scd for a certain time (step S32). The charge control unit 11b is activated (step S33) and set to the charge mode (step S34). That is, the charging control unit 11b inputs an ON signal to the charging switch 13b and sets the charging switch 13b to the ON state. Then, the wireless power Jw is charged in the capacitor 14 for a certain time (step S35). When charging is completed, the electronic key 1 is set to the wireless power supply mode (step S36). That is, the charging control unit 11b inputs an OFF signal to the charging switch 13b and sets the charging switch 13b to an OFF state. The vehicle 2 transmits a power radio wave Svv carrying the request signal Srq following the power radio wave Svv carrying the charge request signal Scd. When receiving the request signal Srq, the electronic key 1 transmits a reflected radio wave carrying the ID code signal Sid (step S37). When the vehicle 2 receives the reflected radio wave carrying the ID code signal Sid and establishes smart communication, the vehicle 2 performs ID collation and permits door lock / unlock.

  In the configuration in which charging is performed before smart communication, a configuration in which the charging switch 13b is turned on when the power radio wave Svv is received may be employed. In this case, as a configuration for switching the charging switch 13b with the power of the received power radio wave Svv, a configuration in which a transistor is incorporated in the charging switch 13b may be employed.

-In the said embodiment, the charge to the capacitor | condenser 14 may be performed not only before and after smart communication but in parallel with smart communication, for example.
In the above-described embodiment, the battery voltage information is a 1-bit code “0” or “1”. However, for example, data for notifying the content of the signal as text information may be used.

-In above-mentioned embodiment, you may make it transmit by including capacitor voltage information in the locking signal S1 or the unlocking signal Sul at the time of wireless communication.
In the above embodiment, the notification time of the capacitor voltage information is not limited to being included in the ID verification communication process, but may be an independent information notification format. For example, the notification of the capacitor voltage information from the electronic key 1 to the vehicle 2 may be periodically performed regardless of the ID verification communication.

In the above embodiment, the capacitor 14 is charged with the wireless power Jw. However, if it is possible to provide an installation space, a secondary battery may be employed instead of the capacitor 14.
In the above embodiment, the charging of the capacitor 14 is not limited to the instruction from the vehicle 2 (charging request signal Scd). For example, when receiving the electric power radio wave Svv, the charging from the vehicle 2 side It may be one that starts operating by itself without charging.

  In the above embodiment, the power switch 13a and the charge switch 13b are not necessarily limited to micro switches, and other switching elements such as transistors may be used.

The electronic key 1 is not limited to the power radio wave power supply mode, and may be in a charging mode in which the charging switch 13b is turned on .

  In the above embodiment, the vehicle transmitter 22 and the vehicle transmitter 23 and the RF receiver 24 are provided separately, but the antennas of the vehicle transmitter 22 and the vehicle transmitter 23 are shared with the RF receiver 24 for RF communication. It is good also as a machine.

  In the above embodiment, the request signal Srq and the power radio wave Svv are not limited to being transmitted from the same outside transmitter 22 and in-vehicle transmitter 23. That is, the transmitter for the request signal Srq and the transmitter for the electric power radio wave Svv may be provided as separate components.

The electronic key 1 may monitor the voltage of the power radio wave Svv when receiving the power radio wave Svv, and start charging the capacitor 14 if the voltage is higher than a threshold value.
In the above configuration, the vehicle 2 may be equipped with an immobilizer system that performs ID verification using the electronic key 1 and short-range wireless communication.

In the above embodiment, authentication is performed from number verification, response verification, and ID code verification, but various authentication formats can be adopted.
In the above embodiment, the frequency of the radio wave used in the electronic key system is not necessarily limited to RF, and a frequency other than RF (for example, LF band) can be used. Further, the frequency when radio waves are transmitted from the vehicle 2 to the electronic key 1 and the frequency when radio waves are returned from the electronic key 1 to the vehicle 2 are not necessarily limited to the same ones, and these may be different frequencies.

  -In the said embodiment, the electronic key system of this example is not necessarily applied only to the vehicle 2, If the communication object which uses an electronic key is communication object, the employ | adopting destination will not be specifically limited.

Next, the technical idea that can be grasped from the embodiment will be described together with the effects.
(A) In the electronic key system according to claim 1, electric power that is provided in the communication target and that continues transmission of the electric power radio wave from the power transmission device for a certain period of time before execution of the smart communication. An electronic key system comprising: a radio wave transmission advance means, wherein the charge execution means obtains the power radio wave from the power transmission device before the smart communication and executes charging to the charging unit.

  According to this configuration, since the charging unit is charged before the smart communication is executed, the charging unit can be charged at an early stage. Therefore, a power source necessary for various communications can be secured first, and a state where the charging voltage is low can be quickly improved.

  (B) In the electronic key system according to any one of claims 1 to 5 and (A), the response signal returned from the electronic key to the communication target during the smart communication is the power radio wave “0” or An electronic key system constructed from reflected radio waves returned as binary information of “1”.

  According to this configuration, the radio signal transmitted from the electronic key to the communication target is a reflected radio wave that is modulated using the power radio wave received by the electronic key. For this reason, it is not necessary to provide a transmission means for newly transmitting a radio signal, and it is possible to efficiently transmit a radio signal to a communication target using power radio waves.

  (C) In the electronic key system according to any one of claims 1 to 5, and (a) and (b), the communication target is a vehicle, and when the ID verification is established, An electronic key system characterized in that starting or stopping of an engine is permitted or executed.

  According to this configuration, since the communication target is a vehicle, it is used in an electronic key system that permits or executes door lock locking / unlocking and engine start / stop. There is no need to worry about locking and unlocking the door lock and starting and stopping the engine.

  DESCRIPTION OF SYMBOLS 1 ... Electronic key, 2 ... Vehicle as communication object, 11 ... Communication control part, 11a ... Memory, 11b ... Charge control part as charge execution means, 11c ... Power supply selection part as power supply switching means, 12 ... Key transmission / reception part , 12a ... transmitter circuit, 12b ... receiver circuit, 12c ... rectifier circuit, 13 ... switching unit, 13a ... power switch as power source switching means, 13b ... charge switch as charge execution means, 14 ... capacitor, 15 ... RF transmitter unit , 17 ... Lock button, 18 ... Unlock button, 21 ... Verification ECU, 21a ... Memory, 21b ... Transmission control unit as power transmission means, 21c ... Power radio wave transmission continuation means, charge request transmission means, and determination means Charging execution unit, 22 ... External transmitter as electric power transmission device, 23 ... In-vehicle transmitter as electric power transmission device, 24 ... RF receiver, 27 ... External door hand , 28 ... touch sensor, 29 ... lock button, 31 ... main body ECU, 32 ... engine ECU, 33 ... engine switch, 37 ... courtesy switch, 38 ... door lock device, Jc ... charging power, Jw ... wireless power, Sac ... Ac signal, Scc ... Challenge signal, Scd ... Charge request signal, Sid ... ID code signal, Sre ... Response signal, Srq ... Request signal, Svi ... Vehicle ID signal, Svw ... Wake power radio wave, Svv ... Power radio wave, Swk ... Wake Code, Vb ... battery voltage, Vw ... radio voltage.

Claims (6)

Smart communication in which an electronic key transmits an ID code in response to an ID code reply request transmitted from a communication target and performs ID collation, and the ID code transmitted by an operation on an operating means provided in the electronic key In an electronic key system capable of both communication with wireless communication that enables operation of the device installed in the communication target on the condition that ID verification is established,
Power transmission means that is provided in the communication target and transmits a power radio wave as a power source during smart communication of the electronic key from the power transmission device installed in the communication target during the smart communication;
Charging execution means provided in the electronic key, acquiring the power radio wave emitted from the power transmission device during the smart communication, and charging a charging unit mounted on the electronic key;
Provided in the electronic key, and when the electronic key performs the wireless communication, comprising a power supply switching means for operating the electronic key with the charging unit as a power source ,
The electronic key system according to claim 1, wherein a response signal that the electronic key returns to the communication target during the smart communication is transmitted by a reflected radio wave that returns the electric power radio wave . The electronic key system according to claim 1.
Power radio wave transmission continuation means provided in the communication target, and after the verification of the smart communication is established, the power radio wave transmission from the power transmission device is continued for a certain period of time,
The electronic key system characterized in that the charging execution means obtains the electric power radio wave from the power transmission device after the smart communication is verified, and charges the charging unit. The electronic key system according to claim 1 or 2,
Provided in the communication target, as a request to start charging the charging unit to the electronic key, comprising a charging request transmission means for transmitting a charging request from the power transmission device to the electronic key,
The electronic key system according to claim 1, wherein the charging execution unit executes charging of the charging unit when receiving the charging request from the power transmission device. The electronic key system according to claim 3.
A determination unit that is provided in the communication target and determines whether a charging voltage of the charging unit is less than a threshold;
The charging request transmission unit transmits the charging request to the electronic key to cause the electronic key to start charging the charging unit when the determination unit determines that the charging voltage of the charging unit is less than a threshold value. An electronic key system characterized by In the electronic key system according to any one of claims 1 to 4,
The electronic key system, wherein the charging unit is a capacitor capable of storing sufficient electric power for the electronic key to perform at least wireless communication. In response to a reply request for an ID code transmitted from a communication target, smart communication for transmitting the ID code and performing ID verification, and establishment of ID verification for the ID code transmitted by an operation on the operating means provided in the communication device In the condition, in the power supply method of the electronic key capable of both communication with wireless communication that enables operation of the device installed in the communication target,
The power radio wave transmitted from the power transmission device installed in the communication target is a power source at the time of smart communication of the electronic key,
Obtaining the electric power radio wave emitted from the power transmission device during the smart communication, charging the charging unit mounted on the electronic key, when performing the wireless communication, the charging unit as a power source ,
The electronic key power supply method characterized in that the response signal that the electronic key returns to the communication target during the smart communication is transmitted by a reflected radio wave that returns the electric power radio wave .

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