JP2013002139A - Electronic key - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic key which allows communication to be performed without waste of generated power, in the case that a secondary battery is charged through manual power generation for resumption of the communication.SOLUTION: A wireless key 2 is provided with a power generation unit 13 which allows a secondary battery 12 to be charged through manual power generation. When the wireless key 2 is disabled to transmit radio waves due to the voltage lower than the minimum radio wave transmission operation voltage of the secondary battery 12 of the wireless key 2, the secondary battery 12 is fed (charged) from a power generator 15 which generates power by manual operation. The power supply is recovered when the battery voltage of the secondary battery 12 reaches the voltage equal to or higher than the minimum radio wave transmission operation voltage. When the power supply is recovered, a wireless signal Swl (unlocking signal Sul) is automatically transmitted from the wireless key 2.

Description

  The present invention relates to an electronic key that wirelessly transmits a radio wave for ID verification to a communication target.

  2. Description of the Related Art Conventionally, a vehicle is equipped with a wireless key system that performs ID collation with a wireless key by narrow-band wireless communication (communication distance: several meters) triggered by communication from an electronic key (see Patent Document 1). In this case, for example, when a door locking / unlocking button provided on the wireless key is operated, a wireless signal having a signal content corresponding to the button operation is transmitted from the wireless key. When the vehicle receives a wireless signal from the wireless key, the vehicle performs ID verification using the ID code in the signal. If ID verification is established, the vehicle performs a door lock locking / unlocking operation.

JP-A-9-72137

  By the way, since the wireless key operates using the battery in the key as a power source, the battery voltage gradually decreases according to the number of times the electronic key is used. When the battery voltage drops to the minimum radio wave transmission operation voltage (a value that does not allow radio wave transmission), the wireless key cannot perform radio wave transmission operation and cannot perform ID verification wirelessly with the vehicle. In this case, the user has to lock and unlock the door by a mechanical operation using a mechanical key, which leads to a problem that this operation is troublesome.

  Therefore, in recent years, for example, the battery of the wireless key is a secondary battery, and a generator that generates power by manual operation is provided in the wireless key. When the battery voltage of the wireless key drops to the lowest radio wave transmission operation voltage, manual operation is performed. Therefore, a technique for generating electricity by a generator and charging a battery is being studied. By doing so, the power supply voltage of the wireless key is restored even temporarily, so that radio waves for ID verification can be wirelessly transmitted from the wireless key.

  However, when the user manually operates the generator to charge the battery, the button operation should be executed immediately with the wireless key. However, if there is a time lag before the button operation, the accumulated charge due to spontaneous discharge during that time May be released and the power supply voltage may drop. At this time, if the power supply voltage falls below the minimum radio wave transmission operation voltage again, the wireless key cannot be used again. Therefore, in this case, since recharging is imposed on the user, there is a problem that the convenience of the user is impaired.

  An object of the present invention is to provide an electronic key that can execute communication without wasting generated power when communication is resumed by charging a secondary battery by power generation by manual operation.

  In order to solve the above-mentioned problems, in the present invention, an electronic key that is wirelessly transmitted to a communication target for radio waves necessary for ID verification can be generated by manual operation. Power generation means capable of charging a secondary battery of the battery, voltage monitoring means for monitoring the voltage of the secondary battery, and the power generation when the key power source is less than the minimum voltage required for radio wave transmission operation for radio wave transmission. When the battery voltage of the secondary battery is recovered by the above, a gist is provided with transmission execution means for automatically transmitting the radio wave for the ID verification.

  According to the configuration of the present invention, when the power source of the electronic key becomes less than the minimum voltage for radio wave transmission operation, the power generation means is caused to generate power by manual operation to supply power to the secondary battery. When the battery voltage of the secondary battery recovers, radio waves for ID verification are automatically transmitted at the time of recovery. For this reason, since radio wave transmission is performed immediately when the battery voltage of the secondary battery is recovered, the power obtained by the power generation means can be used as a power source for radio wave transmission without wasting it.

  In the present invention, the transmission execution means, when the battery voltage of the secondary battery that has become less than the minimum radio transmission operation minimum voltage required for radio transmission has recovered to the minimum radio transmission operation voltage by the power generation, The gist is to automatically transmit radio waves for ID verification. According to this configuration, if automatic transmission of radio waves is performed when the battery voltage of the secondary battery recovers to the minimum radio wave transmission operation voltage, the battery voltage becomes a voltage that enables at least one radio wave transmission. At that time, radio waves are automatically transmitted. In this way, if radio waves are automatically transmitted when the battery voltage required for one radio wave transmission is reached, radio wave transmission can be immediately executed.

  The gist of the present invention is a remote operation key for operating the communication target device by transmitting the radio wave corresponding to the operation means when the operation means provided in the device is operated. According to this configuration, when the battery voltage of the secondary battery is equal to or higher than the minimum radio wave transmission operation voltage, the electronic key is operated by operating the electronic key operation means to remotely control the communication target with the electronic key in this normal time. By the way, in the case of this configuration, when the battery voltage of the secondary battery recovers to a predetermined value by power generation by the power generation means, radio wave transmission from the electronic key is automatically executed, so that the power generation operation is equivalent to the operation of the operation means. Become. Therefore, even when radio waves are transmitted by power generation, it is possible to perform an operation without a sense of incongruity that is different from the normal time.

  ADVANTAGE OF THE INVENTION According to this invention, when charging a secondary battery by power generation by manual operation and restarting communication, communication can be performed without wasting generated power.

1 is a block diagram of a wireless key system according to an embodiment. The graph which shows the time change of the secondary battery of a wireless key. (A), (b) is a schematic diagram which shows the specific example of an electric power generation unit. (A)-(c) is a procedure figure at the time of carrying out electric power transmission by feeding the secondary battery of a wireless key by electric power generation.

Hereinafter, an embodiment of an electronic key embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 1 is provided with a wireless key system 3 that executes ID verification (wireless verification) triggered by communication from the wireless key 2. In the wireless key system 3, the door lock of the vehicle door is locked and unlocked by the remote operation with the wireless key 2. The vehicle 1 corresponds to a communication target, and the wireless key 2 corresponds to an electronic key (remote operation key).

  In this case, the vehicle 1 is provided with a verification ECU (Electronic Control Unit) 4 that performs wireless verification and a body ECU 5 that manages the power source of the in-vehicle electrical components, and these are connected through an in-vehicle bus 6. The ID code of the wireless key 2 registered in the vehicle 1 is registered in the memory (not shown) of the verification ECU 4. The verification ECU 4 is connected to a vehicle receiver 7 that can receive radio waves in the UHF (Ultra High Frequency) band.

  On the other hand, the wireless key 2 is provided with a key control unit 8 that manages the operation of the wireless key 2. An ID code is registered as a unique ID of the wireless key 2 in a memory (not shown) of the key control unit 8. The key control unit 8 is connected to a transmission unit 9 capable of transmitting UHF radio waves. The key control unit 8 is connected to a locking button 10 that is pressed when the door is locked, and an unlocking button 11 that is operated when the door is unlocked. The locking button 10 and the unlocking button 11 are composed of momentary switches, for example. Note that the locking button 10 and the unlocking button 11 constitute an operation means.

  The wireless key 2 is provided with a secondary battery 12 as a main power source (key power source) of the wireless key 2. The secondary battery 12 is made of, for example, a lithium battery and supplies power to the key control unit 8 and the transmission unit 9. Each time the secondary battery 12 is consumed as the operating power supply for the wireless key 2, the power supply voltage (remaining battery capacity) decreases.

  When the lock button 10 is operated with the wireless key 2, the wireless key 2 transmits a lock signal (lock signal) Sl as a wireless signal Swl according to the operation of the lock button 10. The locking signal S1 includes an ID code and a function code for instructing locking. The locking signal S1 is transmitted in a plurality of frames in which many identical frames are arranged. This is because the normal vehicle receiver 7 is intermittently driven for the purpose of power saving, so that the locking signal Sl is captured from the top of the frame at the start timing.

  When the vehicle receiver 7 receives the locking signal Sl and wireless communication is established, the verification ECU 4 performs wireless verification using this ID code. And verification ECU4 will lock a vehicle door, if wireless verification is materialized. When the unlock button 11 is operated with the wireless key 2, an unlock signal (unlock signal) Sul is transmitted from the wireless key 2 as a wireless signal Swl, and the vehicle door is unlocked by the same processing as that for locking. Is done. Note that the wireless signal Swl, the locking signal Sl, and the unlocking signal Sul correspond to radio waves necessary for ID verification.

  The wireless key 2 is provided with a power generation unit 13 that can charge the secondary battery 12 by manual operation. The power generation unit 13 is provided with an operation unit 14 for inputting an operation force necessary for power generation, and a generator 15 that is driven by the operation force of the operation unit 14 to generate electric power. The generator 15 is connected to the secondary battery 12 through electrical wiring. Therefore, in the power generation unit 13 of this example, it is possible to generate the generator 15 by manually operating the operation unit 14 and charge the secondary battery 12 with the generated power. The power generation unit 13 corresponds to power generation means.

  By the way, as shown in FIG. 2, the voltage of the secondary battery 12 of the wireless key 2 gradually decreases according to the number of times of use. The voltage becomes lower than the minimum voltage necessary for operation (minimum radio wave transmission operation voltage Vs), and the wireless key 2 falls into a state where radio wave transmission is impossible (communication impossible state). At this time, since the transmission function of the wireless key 2 is stopped, the power generation unit 13 feeds the secondary battery 12 to restore the voltage of the secondary battery 12. When the battery voltage of the secondary battery 12 recovers to the radio wave transmission operation minimum voltage Vs or higher, the wireless key 2 returns to a state where radio waves can be transmitted (communication enabled state).

  3A and 3B show specific examples of the power generation unit 13. In the specific example of FIG. 3A, the generator 15 is caused to generate power by pulling or pushing back the mechanical key 16 built in the wireless key 2. Further, in the case of the specific example of FIG. 3B, a mechanical key 16 that can be rotated about a shaft portion 18 provided on the handle 17 is attached to a corner portion of the wireless key 2 and the mechanical key 16 is pivoted. By rotating around the portion 18 many times, this rotational force is transmitted to the generator 15 by the gear 19 to generate power.

  As shown in FIG. 1, when the secondary battery 12 that has become less than the lowest radio wave transmission operation voltage Vs is charged by the generator 15, the battery voltage of the secondary battery 12 is the lowest radio transmission operation voltage. A power supply immediate radio wave transmission device 20 that automatically executes wireless communication operation when the voltage returns to the voltage Vs or higher is provided. When the battery voltage of the secondary battery 12 returns to the radio wave transmission operation minimum voltage Vs or more, the power supply immediate radio wave transmission device 20 of this example automatically transmits the wireless signal Swl from the wireless key 2 at that time and performs wireless verification. Let it run automatically.

  As described in the background art, if the battery voltage of the secondary battery 12 is recovered to the lowest radio wave transmission operation voltage Vs, the start of radio wave transmission is conditional on the operation of the lock button 10 and the unlock button 11. This is because if there is a time lag between the time of power feeding and the button operation, the battery voltage of the secondary battery 12 may fall below the radio wave transmission operation minimum voltage Vs again due to natural discharge. Therefore, when the battery voltage of the secondary battery 12 is restored to the radio wave transmission operation minimum voltage Vs by the power supply of the generator 15, the wireless signal Swl is automatically transmitted at that time.

  In this case, the key control unit 8 is provided with a battery voltage monitoring unit 21 that monitors the battery voltage of the secondary battery 12. The battery voltage monitoring unit 21 constantly monitors the battery voltage of the secondary battery 12 while the key control unit 8 is powered on. By the way, even if the battery voltage of the secondary battery 12 becomes less than the minimum radio wave transmission operation voltage Vs, the CPU (Central Processing Unit) of the key control unit 8 can operate with the voltage remaining in the secondary battery 12. Therefore, the battery voltage monitoring unit 21 can monitor the voltage of the secondary battery 12 as long as the battery voltage of the secondary battery 12 does not become “0”. The battery voltage monitoring unit 21 corresponds to voltage monitoring means.

  The key control unit 8 automatically transmits the wireless signal Swl (in this example, the unlock signal Sul) when the battery voltage of the secondary battery 12 returns to the radio wave transmission operation minimum voltage Vs or higher. Is provided. When the radio wave automatic transmission unit 22 confirms that the battery voltage of the secondary battery 12 has returned to a value greater than or equal to Vs from less than the radio wave transmission operation minimum voltage Vs, the radio signal Swl is automatically transmitted from the transmission unit 9. At this time, the radio wave automatic transmission unit 22 transmits the wireless signal Swl in a plurality of frames as in the normal case. The radio wave automatic transmission unit 22 corresponds to transmission execution means.

Next, the operation of the wireless key 2 of this example will be described with reference to FIG. Here, an operation for unlocking (unlocking) the vehicle door is taken as an example.
As shown in FIG. 4A, when the battery voltage of the secondary battery 12 of the wireless key 2 becomes less than the radio wave transmission operation minimum voltage Vs, the transmission function of the wireless key 2 is stopped. That is, even when the lock button 10 or the unlock button 11 is operated, the wireless signal Swl cannot be transmitted from the wireless key 2. At this time, the automatic radio wave transmission unit 22 detects that the battery voltage of the secondary battery 12 is less than the minimum radio wave transmission operation voltage Vs based on the monitoring voltage of the battery voltage monitoring unit 21.

  As shown in FIG. 4B, in order to restore the transmission function of the wireless key 2, the power generation unit 13 is manually operated to generate the generator 15, and the secondary battery 12 is supplied with the generated power. To do. If this power generation operation is continued for a while, the battery voltage of the secondary battery 12 is restored to the radio wave transmission operation minimum voltage Vs or more.

  As shown in FIG. 4C, when the battery voltage of the secondary battery 12 recovers to the radio wave transmission operation minimum voltage Vs or higher, the unlock signal Sul is automatically transmitted from the wireless key 2 at that time. That is, when the radio wave automatic transmission unit 22 confirms that the battery voltage of the secondary battery 12 has recovered to the radio wave transmission operation minimum voltage Vs or more based on the monitoring voltage of the battery voltage monitoring unit 21, the secondary at that time Based on the power of the battery 12, the unlocking signal Sul is automatically transmitted from the transmitter 9. Thereby, wireless communication is started, and if the wireless verification is established, the vehicle door is unlocked.

  By the way, depending on the situation, it is assumed that the secondary battery 12 of the wireless key 2 is “0”, that is, the battery has run out and the wireless key 2 itself stops functioning. At this time, since the battery voltage monitoring unit 21 is also stopped, the battery voltage of the secondary battery 12 cannot be monitored at that time. However, when the secondary battery 12 in the power generation unit 13 is supplied with power, if the battery voltage of the secondary battery 12 recovers to the minimum voltage necessary for the operation of the CPU (CPU operation minimum voltage) and the CPU restarts. At that time, the battery voltage monitoring unit 21 is also restarted, and the battery voltage of the secondary battery 12 can be monitored.

  As described above, in this example, when the wireless key 2 is provided with the manually operated power generation unit 13 and the battery voltage of the secondary battery 12 becomes less than the radio wave transmission operation minimum voltage Vs, the power generation unit 13 performs the secondary operation. When the battery 12 is fed and the battery voltage of the secondary battery 12 recovers to the radio wave transmission operation minimum voltage Vs, the wireless signal Swl is automatically transmitted from the wireless key 2 at that time. For this reason, the power generated by the power generation unit 13 can be efficiently used as the transmission power of the wireless signal Swl without wasting it.

  In general, since the wireless key 2 does not have an indicator or the like indicating the remaining amount of the secondary battery 12, when the power generation unit 13 supplies power to the secondary battery 12, the power supply amount, that is, the secondary battery 12. The current voltage cannot be confirmed visually. For this reason, it is impossible to know when the battery voltage of the secondary battery 12 has reached the lowest radio wave transmission operation voltage Vs during the feeding of the secondary battery 12 by the power generation unit 13. However, since the radio wave transmission is performed when the battery voltage of the secondary battery 12 reaches the radio wave transmission operation minimum voltage Vs, the wireless signal Swl may be transmitted at an optimal timing without an indicator for checking the remaining battery level. Is possible.

  By the way, in the case of the background art, when the vehicle door is unlocked with the wireless key 2 whose secondary battery 12 is less than the minimum radio wave transmission operation voltage Vs, manual power generation operation and operation of the unlock button with the wireless key are performed. 2 operations are required. On the other hand, in the case of this example, the wireless signal Swl is transmitted only by manual power generation operation. For this reason, less operations are imposed on the user, and convenience is improved. Moreover, since the power generation operation is replaced with the unlocking operation, the user can unlock the vehicle door with the wireless key 2 without any discomfort for the user.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) When the secondary battery 12 of the wireless key 2 becomes less than the radio wave transmission operation minimum voltage Vs, the generator 15 is caused to generate power by manual operation to feed (charge) the secondary battery 12. When the battery voltage of the secondary battery 12 becomes equal to or higher than the radio wave transmission operation minimum voltage Vs and the power is restored, the wireless signal Swl (unlock signal Sul) is automatically transmitted at the time of recovery. For this reason, radio wave transmission is performed as soon as the battery voltage of the secondary battery 12 is restored, so that the power obtained by the generator 15 can be used as a transmission power source for the wireless signal Swl without wasting it. Can do.

  (2) If the battery voltage of the secondary battery 12 is restored to the radio wave transmission operation minimum voltage Vs by the power generation operation, the wireless signal Swl is automatically transmitted. Therefore, even if the user does not know the current voltage of the secondary battery 12, Radio wave transmission can be performed at a suitable timing.

  (3) Since the wireless signal Swl is automatically transmitted when the battery voltage of the secondary battery 12 is restored to the radio wave transmission operation minimum voltage Vs by the power generation operation, only the power generation operation is imposed on the user during the radio wave transmission. be able to. Therefore, the convenience at the time of operating a door lock by electric power generation operation can be improved.

  (4) When automatic transmission of radio waves is performed when the battery voltage of the secondary battery 12 recovers to the radio wave transmission operation minimum voltage Vs, the battery voltage becomes a voltage at which radio wave transmission can be performed at least once. Can automatically transmit radio waves. In this way, if the radio wave is automatically transmitted when the battery voltage required for one radio wave transmission is reached, radio wave transmission can be immediately executed without imposing unnecessary power generation on the user.

  (5) When the vehicle key 1 is remotely operated with the wireless key 2 at the normal time when the battery voltage of the secondary battery 12 is equal to or higher than the radio wave transmission operation minimum voltage Vs, the lock button 10 and the unlock button 11 of the wireless key 2 are operated. To do. On the other hand, when the battery voltage of the secondary battery 12 is less than the minimum radio wave transmission operation voltage Vs, the operation of generating the generator 15 is the radio wave transmission operation in the wireless key 2. Therefore, since the power generation operation of the generator 15 is equivalent to the button operation at the normal time, the operation of transmitting the radio wave by the power generation can be an operation without a sense of incongruity that is different from the normal time.

The embodiment is not limited to the configuration described so far, and may be modified as follows.
The radio wave automatically transmitted when the voltage of the secondary battery 12 is recovered by the power generation of the power generation unit 13 is not limited to the unlock signal Sul but may be the lock signal S1.

  For example, the rotation direction (operation direction) of the generator 15 is detected, and when the generator 15 is rotated in one direction and is supplied with power, the lock signal S1 is transmitted. The unlocking signal Sul may be transmitted when the electric power is operated by rotating in the direction.

The lock signal S1 may be transmitted when the power is generated while the lock button 10 is pressed, and the unlock signal Sul may be transmitted when the power is generated while the lock button 11 is pressed.
The automatic transmission of radio waves during power generation is not limited to the condition that the battery voltage of the secondary battery 12 has been restored to the minimum radio wave transmission operation voltage Vs. For example, the condition may be that the battery voltage of the secondary battery 12 is restored to a value higher than the minimum radio wave transmission operation voltage Vs, for example, a voltage necessary for performing a plurality of wireless communications.

The wireless key 2 may have a separate primary battery as a main power source, and when the voltage of the primary battery drops, the secondary battery 12 of this example may be generated and transmitted by radio waves.
The locking button 10 and the unlocking button 11 are not limited to being provided as separate buttons. For example, a single button may be used, and locking / unlocking may be performed alternately each time this button is operated. Good.

-An operation means is not limited to the locking button 10 and the unlocking button 11, For example, the button which opens and closes the sliding door and back door of the vehicle 1 may be sufficient.
The secondary battery 12 is not limited to an independently chargeable battery component (button battery or the like) as a component, for example, and may be a capacitor mounted on the board of the key control unit 8, for example.

The power generation unit 13 is not limited to the example shown in FIGS. 3A and 3B, and can be changed to other structures / shapes as long as the generator 15 can generate power by manual operation.
The vehicle receiver 7 is not limited to intermittent driving, and may be always driven.

  The electronic key system is not limited to the wireless key system 3, and may be appropriately changed to another system as long as it is a communication system in which ID collation is performed in response to communication from the electronic key.

The frequency of radio waves used in the electronic key system is not limited to the UHF band, and other frequencies such as LF (Low Frequency) and HF (High Frequency) may be used.
-The authentication mode of ID collation is not limited to the method of confirming only the ID code, but may be changed to another method (encrypted communication or the like).

  -An electronic key system is good also as a key operation free system which performs ID collation by narrow area wireless communication (communication distance: several m), for example by the communication from the vehicle 1. In the key operation free system, when the electronic key receives the request signal transmitted from the vehicle 1, the electronic key returns an ID signal in response to the request signal, and ID verification is executed using this ID signal. At this time, if the ID verification with the electronic key outside the vehicle is established, the locking / unlocking of the vehicle door is permitted / executed, and if the ID verification with the electronic key inside the vehicle is established, the engine can be simply pressed by the engine switch inside the vehicle. Start is allowed.

  The electronic key system may be a short-range wireless communication system, for example. The short-range wireless communication system is a kind of an authentication system having a short communication distance (about 10 centimeters) using, for example, NFC (Near Field Communication).

  The electronic key is not limited to the wireless key 2 and can be appropriately changed to, for example, a smart key or an IC card according to a communication system to be used (for example, a key operation free system or a short-range wireless communication system).

The electronic key system is not limited to being applied to the vehicle 1, but can be applied to other devices and apparatuses such as houses.
Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below together with their effects.

  (A) In any one of claims 1 to 3, the secondary battery is a main power source used as an operating power source during normal operation. According to this configuration, since only the secondary battery needs to be mounted on the electronic key, it is highly effective in simplifying the structure of the electronic key and reducing component costs.

  (B) In any one of claims 1 to 3 and the technical idea (a), it is used as a key of a vehicle electronic key system. According to this configuration, convenience can be secured in the electronic key of the vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle as communication object, 2 ... Wireless key as electronic key (remote control key), 10 ... Lock button which comprises operation means, 11 ... Unlock button which comprises operation means, 12 ... Secondary battery, 13 ... power generation unit as power generation means, 21 ... battery voltage monitoring section as voltage monitoring means, 22 ... automatic radio wave transmission section as transmission execution means, Swl (Sl, Sul) ... wireless signal as radio waves, Vs ... radio wave transmission operation Minimum voltage.

Claims (3)

In an electronic key whose validity is confirmed by wirelessly transmitting radio waves necessary for ID verification to the communication target,
Power generation means capable of generating power by manual operation and capable of charging the secondary battery in the key by this power generation;
Voltage monitoring means for monitoring the voltage of the secondary battery;
Transmission execution means for automatically transmitting radio waves for the ID verification when the battery voltage of the secondary battery is recovered by the power generation when the key power source is less than the minimum radio wave transmission operation minimum voltage required for radio wave transmission; An electronic key characterized by comprising: When the battery voltage of the secondary battery that has become lower than the minimum radio wave transmission operation minimum voltage necessary for radio wave transmission is restored to the minimum radio wave transmission operation voltage by the power generation, the transmission execution unit performs the ID verification. The electronic key according to claim 1, wherein the electronic key is automatically transmitted. 3. A remote operation key for operating the communication target device by transmitting the radio wave corresponding to the operation means when an operation means provided in the device is operated. Electronic key as described in

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