TW201315883A - Electronic key - Google Patents

Abstract

Disclosed is an electronic key that enables a communication object to authenticate the key in the event of a power short interruption. The key is provided with a counter, which consumes the power of a battery and will be incremented each time the switch is operated. When the switch is operated, the electronic key transmits wireless signals including the first information used as the value of the counter and the inherent key information of the electronic key. A communication host, upon receiving wireless signals, determines whether the first information and the key information correspond to the communication host, and if the first information and the key information correspond to the communicating host, equipment of the communication host is activated, wherein the communication host stores, upon receiving the wireless signals that correspond to the communicating host, the first information contained in the received wireless signals as the second information, and when the first information contained in the wireless signals received subsequently is greater than the stored second information, it is determined that the received wireless signals correspond to the electronic key and the high bit followed by the low bit will be rewritten when the counter is subjected to the carry process.

Description

Electronic key

The invention relates to an electronic key.

Conventionally, as disclosed in Patent Document 1, it is known that a user performs an electronic key system such as locking and/or unlocking of a door by operating a switch provided on an electronic key. The system's electronic key has: a memory that stores an inherent ID code; and an operating counter that counts the number of operations of the switch. When the switch is operated, the electronic key transmits a wireless signal including an ID code, an operation count of the operation counter, and control information corresponding to the switch.

The vehicle includes: a memory that stores an ID code identical to the previous ID code; and a reception counter that counts the number of receptions of the wireless signal. As soon as the vehicle receives the wireless signal from the electronic key, does the ID code contained in the wireless signal match the ID code stored in the memory of the vehicle, and the number of operations and the number of receptions stored in the receiving counter are Make judgments consistently. When the ID code included in the wireless signal coincides with the ID code stored in the memory of the vehicle, and the number of operations coincides with the number of receptions stored in the reception counter, the vehicle determines that the received wireless signal is from the vehicle Corresponding electronic key. Then, according to the control information contained in the wireless signal, the locking and/or unlocking of the door is performed.

Patent Document 1: Japanese Patent Laid-Open No. Hei 8-303078

In such an electronic key system, for example, in the case where the electronic key and the vehicle are far apart, or there is an obstacle between the electronic key and the vehicle, sometimes the wireless signal transmitted from the electronic key cannot be used by the vehicle. receive. In this case, since the user operates the switch of the electronic key, the number of operations counted by operating the counter increases. Therefore, after the electricity When the sub-key and the vehicle can be appropriately wirelessly communicated, the number of operations included in the wireless signal does not match the number of receptions of the reception counter. To be precise, the number of operations contained in the wireless signal is greater than the number of receptions of the receive counter. Therefore, when many vehicles judge whether or not the received wireless signal is from an electronic key corresponding to the vehicle, the determination is made based on whether the number of operations is equal to or greater than the number of receptions of the reception counter. That is to say, when the number of operations is greater than or equal to the number of receptions, it is determined that the received wireless signal corresponds to the electronic key, and when the number of operations is less than the number of receptions, it is determined that the received wireless signal does not correspond to the electronic key.

On the other hand, many electronic keys are powered by batteries to provide the power needed to transmit wireless signals. In the short term, when the battery is supplied to each part of the electronic key, the voltage of the battery temporarily drops, and then returns to a value close to that before the supply. Since the power supply of the battery is repeatedly repeated for a long time, the voltage of the battery gradually decreases. When the battery is exhausted, there is a problem that the voltage value of the battery is temporarily lower than the voltage value required for the electronic key to perform various operations. In this case, a momentary interruption of the power supply from the battery to each part of the electronic key occurs. In the event of a momentary break, various actions stop.

The operation counter rewrites the data each time the switch of the electronic key is operated. For example, the case where the operation counter is decimal is explained. When the operation counter is in a state of one bit, when a switch is operated, one bit is rewritten to 0 and the ten bits are rewritten to a value increased by one.

A momentary break sometimes occurs when the operating counter overwrites the data. In particular, the switch is operated in a state where the bit is 9, and the ten bits are not overwritten (not incremented) when a moment occurs after the bit is reset to zero. Therefore, the value of the operation counter is less than the value of the reception counter. When the switch is operated again, the electronic key transmits a wireless signal containing the number of operations (i.e., ten digits that have not been incremented). However, since the number of operations included in the wireless signal is greater than the receiver The value of the counter is small, so the vehicle does not recognize that the electronic key as the sender of the wireless signal is a regular electronic key corresponding to the vehicle.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electronic key capable of causing a communication object to authenticate an electronic key in the event of a momentary break.

In order to solve the above problems, a first aspect of the present invention provides an electronic key including a counter that consumes power of a battery and that is incremented each time a switch that can be operated from the outside is operated, when the switch is operated The electronic key transmits a wireless signal including first information as a value of the counter and key information unique to the electronic key, and the communication host that receives the wireless signal determines the first information and the Whether the key information corresponds to the communication host, and when the first information and the key information correspond to the communication host, causing the device of the communication host to operate, wherein the communication host receives the When the wireless signal corresponds to the communication host, the first information included in the received wireless signal is stored as the second information, and the first information included in the received wireless signal is stored in the second information ratio. When the information is large, it is determined that the received wireless signal corresponds to the electronic key, and when the counter is in the carry position, the lower bit is rewritten after the high bit is overwritten.

The larger the value of the higher bit in the value of the counter and the larger the value of the lower bit, the larger the value. Based on this configuration, the counter rewrites the low bit after rewriting the high bit while the carry is being carried. Therefore, when a short-circuit of the battery to temporarily stop the power supply to the counter occurs during the period from the rewriting of the high bit to the rewriting of the low bit, the counter stops when only the high bit is rewritten and the low bit is not rewritten. stop. In this case, the value of the counter is larger than before the operation of the switch. As a result, the first information included in the wireless signal transmitted by the electronic key is larger than the information contained in the previous signal (that is, the second information). When the first information is larger than the second information stored in the communication host, the communication host determines that the electronic key corresponds to the communication host. Since the first information included in the wireless signal does not decrease even when a momentary break occurs, the electronic key can cause the corresponding communication host to recognize that the electronic key corresponds to the communication host.

In one example, the electronic key includes a determination unit that determines whether the momentary interruption occurs from rewriting the high position when a moment when the power supply of the battery is temporarily stopped is generated. In the period until the lower bit is rewritten, the counter rewrites the lower bit when the determination unit determines that the momentary break occurs from the time of rewriting the upper bit to the time of rewriting the lower bit.

In the state where only the high bit is rewritten without rewriting the low bit, when the switch is operated, the high bit is rewritten again. In this case, for the number of operations, the high position will reach the upper limit in advance. Then, based on this configuration, when a momentary break occurs in the period from the rewriting of the upper bit to the rewriting of the lower bit, the lower bit is rewritten. That is, the value of the counter is rewritten to the correct value corresponding to the number of operations of the actual switch. Thereby, it is possible to suppress the high bit from being continuously rewritten.

In one example, in the electronic key, the lower bit is composed of a second storage area and a third storage area, and the operation is performed each time the switch is operated in an even state in which the first storage area of the upper position is an even number The second storage area is rewritten, and the third storage area is rewritten each time the switch is operated in the odd state of the upper position.

According to this configuration, when the switch is operated in a state where the second storage area is at the upper limit value, the first storage area is rewritten to an odd number, and the switch is operated in a state where the third storage area is at the upper limit value. At the time, the first storage area is rewritten to an even number. For example, when the third storage area is in the upper limit value, the switch is operated, and when a transient occurs in the period from the rewriting of the upper bit to the rewriting of the third storage area, the upper bit is an even number and the third storage area is upper. The status of the limit. Normally, since the third storage area is rewritten when the upper bit is an odd number, the state in which the upper bit is an even number and the third storage area becomes an upper limit value occurs only when the counter is stopped by a momentary interruption. In the state in which the second storage area is in the upper limit value, when the same transient as described above occurs, the counter is stopped in a state where the upper bit is an odd number and the second storage area is an upper limit value. This state also occurs only when the counter is stopped due to a momentary interruption. In this way, it can be easily determined that a break has occurred during the period from the rewriting of the upper bit to the rewriting of the lower bit.

In one example, in the electronic key, the counter has a plurality of blocks storing a value of the upper bit and a value of the lower bit, when a value of the upper bit of a block is rewritten, and When the rewritten value reaches the block change value as a criterion for determining whether or not to change the block, the counter rewrites the value in the other block different from the one block.

Based on this configuration, for example, the number of times the number of operations of the switch is counted can be increased by a plurality of blocks as compared with the case of having only one block.

According to a second aspect of the present invention, there is provided an electronic key including a first counter that consumes electric power of a battery and that is incremented each time a switch that can be operated from the outside is operated, when the switch is operated The electronic key transmits a wireless signal including first information as a value of the first counter and key information unique to the electronic key, and a communication host that receives the wireless signal determines the first information And determining whether the key information corresponds to the communication host, and when the first information and the key information correspond to the communication host, causing a device of the communication host to operate, wherein the communication host is provided with wireless The number of times the signal is received The second counter of the line count determines that the received wireless signal and the electronic key are greater when the first information included in the received wireless signal is greater than the second information that is the value of the second counter. Correspondingly, when the first counter is in the carry position, the lower bit is rewritten after the high bit is overwritten.

According to this configuration, the same effects as those described in the first aspect can be obtained.

The present invention provides an electronic key that enables a communication object to authenticate an electronic key in the event of a momentary break.

Hereinafter, an embodiment of an electronic key of the present invention will be described with reference to Figs. 1 to 3 .

As shown in FIG. 1, an electronic key system 1 is mounted on a vehicle 10, and the electronic key system 1 performs ID verification by communicating with an electronic key 20 by a wireless signal.

<electronic key>

The electronic key 20 includes an electronic key control unit 21 configured by a computer unit composed of a CPU or the like, and a UHF transmitting unit 23 electrically connected to the electronic key control unit 21. The UHF transmitting unit 23 modulates the signal generated by the electronic key control unit 21 into a UHF (Ultra High Frequency) band and transmits the signal.

Further, the electronic key 20 is provided with a lock switch 24 and an unlock switch 25 that can be operated from the outside. These switches 24, 25 are electrically connected to the electronic key control unit 21.

The electronic key control unit 21 includes a nonvolatile memory 21a and a counter 22. In the memory 21a, a unique ID code shared with the vehicle 10 is stored. The counter 22 counts the number of operations of the switches 24, 25. In addition, the specific configuration of the counter 22 and the operation of the counter 22 will be described in detail later.

Further, the electronic key 20 includes a battery 26 that supplies electric power to each unit of the electronic key 20 such as the electronic key control unit 21. Battery 26 is a replaceable primary battery. The electronic key control unit 21 consumes electric power supplied from the battery 26 and drives it.

When the lock switch 24 or the unlock switch 25 is operated, and an electric signal indicating the information is input to the electronic key control unit 21, the counter 22 is incremented. Then, the electronic key control unit 21 generates a first encryption code that encrypts the ID code stored in the memory 21a, and a second encryption code that encrypts the value (count data) of the counter 22. Then, the electronic key control unit 21 generates a wireless signal including the first encryption code and the second encryption code, and the operation content indicating the locking or unlocking of the door associated with the operated switch, and the signal is directed to The UHF transmitting unit 23 outputs. The UHF transmitting unit 23 modulates the wireless signal, and transmits the modulated wireless signal as a wireless signal of the UHF band.

<vehicle>

The vehicle 10 includes an in-vehicle control unit 11 that controls various in-vehicle devices, and a UHF receiving unit 13 that is electrically connected to the in-vehicle control unit 11 and receives a wireless signal of a UHF band. The UHF receiving unit 13 demodulates the received wireless signal, and outputs the demodulated signal to the in-vehicle control unit 11. Further, the vehicle 10 is provided with a door lock device 14, and the door lock device 14 is also electrically connected to the in-vehicle control unit 11. The door lock device 14 switches the locking and unlocking of the door (not shown).

A nonvolatile (volatile) memory 11a is provided in the in-vehicle control unit 11. In the memory 11a, a unique ID code shared between the electronic key 20 and the electronic key 20 is stored. Further, in the memory 11a, data (count data) included in the received wireless signal is also stored.

The in-vehicle control unit 11 receives the wireless mail from the electronic key 20 via the UHF receiving unit 13. number. The in-vehicle control unit 11 decrypts the first encryption code and the second encryption code included in the wireless signal to obtain an ID code and count data. Then, the in-vehicle control unit 11 determines whether or not the decrypted ID code and the count data are information transmitted from the electronic key 20 corresponding to the vehicle 10. That is, it is determined whether or not the received ID code coincides with the ID code stored in the memory 11a of the in-vehicle control unit 11. Further, it is judged whether or not the received count data is larger than the previous count data stored in the memory 11a of the in-vehicle control unit 11. When the ID code matches and the count data is larger than the count data stored in the memory 11a of the in-vehicle control 11, the in-vehicle control unit 11 determines that the wireless signal is transmitted from the electronic key 20 corresponding to the vehicle 10. Then, when it is determined that the received wireless signal is from the electronic key 20 corresponding to the vehicle 10, the door lock device 14 is operated in accordance with the content of the operation included in the wireless signal. Further, at this time, the in-vehicle control unit 11 rewrites the count data (the data received last time) stored in the memory 11a into the count data received this time.

<counter>

As shown in FIG. 1, the counter 22 is provided with the first block 22a to the sixth block 22f, and these blocks are areas for storing the number of operations. Since the first block 22a to the sixth block 22f have the same configuration, only the configuration of the first block 22a will be described here.

As shown in FIG. 2, the first block 22a includes the first storage area 31 to the third storage area 33. The first storage area 31 is a carry area, and the second storage area and the third storage area are count areas. The first storage area 31 is one bit higher than the second storage area 32 or the third storage area 33. The second storage area 32 and the third storage area 33 are in the same position. The counter 22 is in hexadecimal, and hexadecimal uses 100 symbols (values) of 00 to 99, and a symbol larger than the upper limit value of the second storage area 32 and the third storage area 33 (i.e., 99) is one. a first storage area one bit higher than the second storage area 32 and the third storage area 33 The symbol combination is represented. When the switches 24 and 25 are operated, the counter 22 rewrites the second storage area 32 when the first storage area 31 is an even number (including 00), and rewrites the third storage area when the first storage area 31 is an odd number. 33. When the switches 24 and 25 are operated in a state where the values of the second storage area 32 or the third storage area 33 have reached the upper limit value (i.e., 99), the counter 22 rewrites the value (increment) of the first storage area 31.

<Action of the counter>

Next, the operation of the counter 22 will be described. Here, the first block 22a to the sixth block 22f are in the state A shown in FIG. 2. State A is a state in which the values of the first storage area 31 to the third storage area 33 are 00.

When the electronic key control unit 21 receives an electric signal from the switches 24 and 25, the electronic key control unit 21 confirms the numerical value of the first storage area 31 of the first block 22a. Here, since the numerical value of the first storage area 31 is 00 (even number), the electronic key control unit 21 increments the numerical value of the second storage area 32 (the value is incremented by one). Thus, the counter 22 becomes the state B (normally counted). When the increment is repeated, the counter 22 becomes the state C in which the first storage area 31 and the third storage area 33 are 00 and the second storage area 32 is the upper limit (that is, 99).

In the state C, when the switches 24, 25 are operated, the electronic key control unit 21 increments the value of the first storage area 31 (the value is incremented by one) and causes the counter 22 to transition to the state D, and then the second storage area The value of 32 is reset to 00 and the counter 22 transitions to state E (the number of carrys).

In the state E, when the switches 24 and 25 are operated, since the value of the first storage area 31 is 01 (odd number), the electronic key control unit 21 increments the numerical value of the third storage area 33 (the value is incremented by one). Thus, the counter 22 becomes the state F (normally counted). When the increment is repeated, the counter 22 has the first storage area 31 being 01, the second storage area 32 being 00, and the third storage. The storage area 33 is in the state G of 99.

In the state G, when the switches 24, 25 are operated, the electronic key control unit 21 increments the value of the first storage area 31 (the value is incremented by one) and causes the counter 22 to transition to the state H, and then the third storage area The value of 33 is reset to 00 and the counter 22 transitions to state I (the number of carrys). Further, the state I is a state in which the value of the first storage area 31 is larger than the state A by two.

When the first block 22a is in the state I and the switches 24 and 25 are operated, the electronic key control unit 21 starts counting of the second block 22b. That is, the value of the second storage area 32 of the second block 22b is incremented (value added by 1). Thereafter, each time the switches 24 and 25 are operated, the electronic key control unit 21 counts the second block 22b in the same manner as the first block 22a. These series of operations are repeated in the order of the third block 22c, the fourth block 22d, the fifth block 22e, and the sixth block 22f, and the first block 22a to the sixth block 22f are all in the state I. At this time, the electronic key control unit 21 restarts the counting of the first block 22a. In other words, when the value of the first storage area 31 is incremented (the value is incremented by 2), the electronic key control section 21 transitions the rewritten object to the next block. Further, the count data is a combination of all values of the first block 22a to the sixth block 22f.

Here, each part of the electronic key 20 consumes the electric power of the battery 26 and operates. Therefore, when the battery 26 is depleted or the like, and the voltage of the battery 26 is lowered, the respective portions of the electronic key 20 are driven, and a momentary break may occur. Sometimes this short break occurs when the counter 22 is overwriting the value. In other words, there is a case where a short-circuit occurs in a period from the increment of the first storage area 31 to the time when the second storage area 32 or the third storage area 33 is reset (during the number of carryes). Then, in the case where a momentary break has occurred, the electronic key control unit 21 determines whether or not the momentary occurrence occurs when the counter 22 is rewriting the value, in particular, whether or not the number of carry occurs, and it is judged that the momentary occurrence occurs. When the number of carryes is in progress, it is judged whether or not the second storage area 32 or the third storage area 33 is positive. Correctly rewritten. Then, when the second storage area 32 or the third storage area 33 is not correctly rewritten, these storage areas are corrected. Referring to the flowchart shown in FIG. 3, various processes such as these series of determinations and corrections are executed by the electronic key control unit 21.

First, it is determined from the electronic key control unit 21 after the momentary recovery that the first storage area 31 is an even number (step S1). When YES in step S1, that is, when the first storage area 31 is an even number, it is determined whether or not the third storage area 33 is 99 (upper limit value) (step S2). In the case of normal counting, when the first storage area 31 is an even number, the second storage area 32 is rewritten, and the third storage area 33 is 00. In addition, the switches 24 and 25 are operated only in the state (state G) in which the first storage area 31 is an odd number and the third storage area 33 is an upper limit value (ie, 99), and the first storage area 31 is operated. When the value is incremented and rewritten to an even number of instants, that is, the number of carryes, the first storage area 31 is rewritten to an even number. Then, when YES in step S2, that is, when the third storage area 33 is 99, when the rewriting (reset) of the third storage area 33 is not performed by the momentary interruption, the third storage area 33 is reset to 00. (Step S3), and the processing is ended.

Further, when NO in step S2, that is, when the third storage area 33 is not 99, since the value of the counter 22 is correctly rewritten in the process of the number of carry-in, the electronic key control unit 21 ends the processing.

In the case where NO in step S1, that is, when the first storage area 31 is an odd number, it is determined whether or not the second storage area 32 is 99 (step S4). In the case of normal counting, when the first storage area 31 is an odd number, the third storage area 33 is rewritten, and the second storage area 32 is 00. In addition, the switches 24 and 25 are operated and the first storage area 31 is operated only in a state (state D) in which the first storage area 31 is an even number and the second storage area 32 is an upper limit value (ie, 99). When the value is incremented and rewritten into an odd number of instants, that is, the number of carryes, the first storage area 31 is rewritten to an odd number. to If YES in step S4, that is, when the second storage area 32 is 99, when the second storage area 32 is not rewritten (reset) due to a momentary interruption, the second storage area 32 is reset to 00. (Step S5), and the processing is ended.

In the case where NO in step S4, that is, when the second storage area 32 is not 99, since the value of the counter 22 is correctly rewritten in the process of the number of carry-in, the electronic key control unit 21 ends the processing.

As described above, according to the present embodiment, the following effects can be obtained.

(1) A counter 22 that counts the number of operations of the switches 24, 25 is provided on the electronic key 20. The counter 22 is provided with the second storage area 32 and the third storage area 33 which are incremented each time the switches 24 and 25 are operated, and the switch 24 in the state where the second storage area 32 or the third storage area 33 is the upper limit value. And 25 are composed of the first storage area 31 which is incremented by the operation. Then, after the first storage area 31 is incremented, the second storage area 32 and the third storage area 33 are reset. Accordingly, when the momentary interruption occurs in the period from the increment of the first storage area 31 to the time when the second storage area 32 is reset, the counter 22 does not operate the second storage area 32 and the third storage area 33. The reset is performed and only the first storage area 31 is stopped in an incremental state. That is, the value of the counter 22 is larger than before the operation of the switches 24, 25. As a result, the count data contained in the wireless signal transmitted by the electronic key 20 is larger than the count data contained in the previous signal. When the count data included in the received wireless signal is larger than the count data stored in the memory 11a of the vehicle 10, the vehicle 10 determines that the electronic key is corresponding to the vehicle 10 on the condition that the ID verification is established. Formal electronic key 20. Since the count data contained in the wireless signal transmitted by the regular electronic key 20 does not decrease even if a momentary break occurs, the electronic key 20 can cause the corresponding vehicle 10 to recognize the electronic key 20 and the vehicle 10 correspond.

(2) When a momentary break occurs, the electronic key control unit 21 determines whether or not the momentary occurrence has occurred from the increment of the first storage area 31 to the second storage area 32 or the third storage area 33 is reset. In the period of time, it is determined that the momentary occurrence occurs during the period from when the first storage area 31 is incremented until the second storage area 32 or the third storage area 33 is reset, and the second storage area 32 is either The third storage area 33 is reset. Thereby, the electronic key 20 can include the count data corresponding to the number of operations of the switches 24, 25 in the wireless signal.

Further, the above embodiment may be changed to the following form.

‧ In the above embodiment, the counter 22 includes the first block 22a to the sixth block 22f. However, the number of blocks is not limited to six. For example, the number of blocks may be one, or two or more blocks may be used. Even in the case of being configured in this manner, the same effects as those of the above embodiment can be obtained. In addition, for example, compared with the case of having only one block, having a plurality of blocks can increase the number of times of counting the number of operations of the switch.

‧ In the above embodiment, the third storage area 33 may be omitted. In this case, the correction of the counter 22 by the electronic key control unit 21 can be omitted. For example, when the second storage area 32 is 99 (upper limit value), the switches 24 and 25 are operated, and when the first storage area 31 is incremented, the second switch is not reset. Storage area 32. That is, when the next switch 24, 25 is operated, the first storage area 31 is incremented again. Even in the case of such a configuration, the electronic key 20 can transmit count data larger than the count data previously transmitted when the switches 24, 25 are operated. The in-vehicle control unit 11 determines that the count data received this time corresponds to the in-vehicle control unit 11 as long as the count data received this time is larger than the previously received count data, so even in this case, The door lock device 14 of the vehicle 10 can be operated.

‧In the above embodiment, the hexadecimal number is used, and 100 symbols (values) of 00 to 99 are used, and the upper limit value of the second and third storage areas 32, 33 (ie, 99) is used. The symbol (value) of the large 1 is represented by a combination of the symbols of the first storage area one bit higher than the second storage area 32 and the third storage area 33. However, binary, decimal, twelve-digit, ten may also be used. Six-digit, etc., other bit-by-digit system. Even in the case of being configured in this form, the same effects as those of the above embodiment can be obtained.

In the above embodiment, the in-vehicle control unit 11 compares the previously received count data with the count data received this time to determine whether or not the electronic key 20 as the wireless signal sender corresponds to the in-vehicle control unit 11, but It can be judged by other methods. For example, a reception counter that counts the number of receptions of the wireless signal may be provided on the vehicle 10, and the on-board control unit 11 compares the count data of the reception counter with the received count data to determine the sender of the wireless signal. Whether or not the electronic key 20 corresponds to the in-vehicle control unit 11. Even in the case of being configured in this form, the same effects as those of the above embodiment can be obtained.

‧ In the above embodiment, in the electronic key system 1, only one-way communication is performed between the vehicle 10 and the electronic key 20, but in addition to the one-way communication, two-way communication can be performed. Even in the case of being configured in this form, the same effects as those of the above embodiment can be obtained.

‧ In the above embodiment, the battery 26 is a primary battery, but may be a secondary battery such as a rechargeable secondary battery. Even in the case of being configured in this form, the same effects as those of the above embodiment can be obtained.

‧Although in the above embodiment, the present invention is applied to an electronic key system of the vehicle 10 However, the present invention can also be applied to an electronic key system of a building such as a house.

1‧‧‧Electronic key system

10‧‧‧ Vehicles

11‧‧‧Car Control Department

11a, 21a‧‧‧ memory

13‧‧‧UHF Receiving Department

14‧‧‧Door locking device

20‧‧‧Electronic Key

21‧‧‧Electronic Key Control Department

22‧‧‧ counter

22a~22f‧‧‧1st block~6th block

23‧‧‧UHF transmission department

24‧‧‧Lock switch

25‧‧‧Unlock switch

26‧‧‧Battery

31~33‧‧‧1st storage area~3rd storage area

S1-S5‧‧‧ steps

FIG. 1 is a block diagram showing a schematic configuration of an electronic key system according to the present embodiment.

Fig. 2 is a view showing a count form of a counter.

Figure 3 is a flow chart executed after recovery from a momentary break.

22a~22f‧‧‧1st block~6th block

31~33‧‧‧1st storage area~3rd storage area

Claims (5)

An electronic key provided with a counter that consumes power of a battery and is incremented each time a switch operable from the outside is operated, and when the switch is operated, the electronic key transmission includes as the counter a wireless signal including the first information of the value and the key information unique to the electronic key, and the communication host that receives the wireless signal determines whether the first information and the key information correspond to the communication host. When the first information and the key information correspond to the communication host, the device of the communication host is operated, wherein the communication host, when the wireless signal received by the communication host corresponds to the communication host, The first information included in the received wireless signal is stored as the second information, and when the first information included in the received wireless signal is larger than the stored second information, the received wireless is determined to be the received wireless The signal corresponds to the electronic key, and the counter rewrites the low bit after overwriting the high bit. The electronic key according to claim 1, wherein the determination unit is configured to determine whether the momentary interruption occurs when the high level is rewritten from when the power supply of the battery is temporarily stopped. In the period until the lower bit is rewritten, the counter rewrites the lower bit when the determination unit determines that the momentary break occurs from the time of rewriting the upper bit to the time of rewriting the lower bit. The electronic key according to claim 2, wherein the lower bit is composed of the second storage area and the third storage area, and the operation is performed each time the switch is operated in an even state in which the first storage area of the upper position is an even number The second storage area is rewritten, and the third storage area is rewritten each time the switch is operated in the odd state of the upper position. The electronic key according to any one of claims 1 to 3, wherein the counter has a plurality of blocks storing a value of the upper bit and a value of the lower bit, when the high bit of a block When the value is rewritten, and the rewritten value reaches the block change value as a criterion for determining whether to change the block, the counter rewrites the value in the other block different from the one block. . An electronic key provided with a first counter that consumes power of a battery and is incremented each time a switch operable from the outside is operated, and when the switch is operated, the electronic key transmission includes The first information of the value of the first counter and the wireless signal including the key information specific to the electronic key, and the communication host that has received the wireless signal determines whether the first information and the key information are Corresponding to the communication host, when the first information and the key information correspond to the communication host, the device of the communication host is operated, wherein the communication host has a count of the number of times the wireless signal is received a counter that determines that the received wireless signal corresponds to the electronic key when the first information included in the received wireless signal is greater than the second information that is the value of the second counter When the first counter is in the carry position, the lower bit is rewritten after the high bit is overwritten.