JP2010095866A - Portable machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable machine effectively utilizing a received radiowave when receiving a noise radiowave. <P>SOLUTION: When receiving the radiowave in a predetermined frequency band, i.e., the noise radiowave different from a first signal A1, the portable machine moves in a charging mode. In the charging mode, the secondary battery of the portable machine is charged. The power obtained from the radiowave received in the charging mode is used as a power for charging the secondary battery, and a determination treatment by a determination means in the charging mode may not be adopted. By moving to the charging mode when receiving the noise radiowave and concentrating to the charging to the secondary battery, the portable machine effectively utilizes the received radiowave. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a portable device possessed by a user, and more particularly, to a portable device including a secondary battery.

  For example, according to a so-called electronic key system disclosed in Patent Document 1, a vehicle user possesses a regular portable device suitable for the vehicle and approaches the vehicle, so that the portable device has security on the vehicle side. A request signal transmitted from the apparatus is received. Then, in response to the request signal, this portable device transmits a response signal including an ID code individually set in the own device. And when this response signal is received by the vehicle side security device and the ID code that matches the reference ID code is included in the signal, it is determined that the legitimate portable device is used and possesses it. In order to allow the vehicle user to get in, the door is unlocked, that is, the door is unlocked.

  In addition, a portable device provided for this type of electronic key system receives power from a battery (primary battery) built in the device and receives a request signal or transmits a response signal. Various operations are possible. The request signal is a generic term for a first signal A1 including a WAKE code, a second signal A2 including a vehicle code, a third signal A3 including a challenge code, and the like. In the present example, the first to third signals A1 to A3 are first to third as shown in FIG. 5A in the frequency band of 100 to 150 kHz in the LF frequency band defined by the Radio Law. Are sequentially transmitted in the periods T1 to T3. Here, the period from the rising edge of the first signal A1 to the rising edge of the second signal A2 is the first period T1. Similarly, the period from the rising edge of the second signal A2 (third signal A3) to the rising edge of the third signal A3 (next signal) is the second period T2 (third period T3). On the other hand, the portable device returns first to third response signals B1 to B3 as shown in FIG. 5B in response to the first to third signals A1 to A3 transmitted from the security device.

Specifically, when the portable device enters the area where the request signal can be received and receives the first signal A1, the microcomputer of the portable device collates the WAKE code included in the first signal A1 with the reference WAKE code. And when both codes correspond, a portable machine returns 1st response signal B1 to the vehicle side. When the control device on the vehicle side receives the first response signal B1, the second signal A2 including the vehicle code is transmitted, and when the portable device receives the second signal A2, the microcomputer of the portable device is included in the second signal A2. The vehicle code to be checked and the reference vehicle code are collated. When the two codes match, the portable device returns a second response signal B2 to the vehicle side. When the control device on the vehicle side receives the second response signal B2, it transmits the third signal A3 including the challenge code, and when the portable device receives it, the microcomputer of the portable device is included in the third signal A3. The challenge code and the standard challenge code are verified. Then, when both codes match, the portable device returns a third response signal B3 to the vehicle side. When the control device on the vehicle side receives the third response signal B3, it checks the identification code included in the third response signal B3 with the reference identification code registered in itself, and if both codes match. Determines that the communication partner is a portable device registered in the vehicle. The vehicle control device permits the door lock to be locked or unlocked.
JP 2007-336102 (paragraphs [0003] to [0006])

  By the way, a dark current always flows through the portable device so that a request signal transmitted from the vehicle side can always be received. When a portable device in this state is stored near an electronic device that emits radio waves in the same frequency band as the request signal, such radio waves (for mobile phones, this is a noise radio wave) However, the portable device performs processing such as the above-described determination.

  Specifically, when a noise radio wave as shown in FIG. 5C is received, the portable device collates the WAKE code in the same manner as when the first signal A1 is received. In this case, since the WAKE codes do not match, the microcomputer of the portable device ends the determination without returning the first response signal B1, but consumes power for this determination. Thereafter, the portable device performs the same determination process as long as it is in a noise environment. For this reason, by receiving the noise radio wave, the portable device repeats the determination process, and the battery of the portable device is consumed.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a portable device capable of effectively utilizing a received radio wave when a noise radio wave is received.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
The invention according to claim 1 is a receiving device for receiving a radio wave of a specific frequency band including a regular signal suitable for the portable device in a portable device possessed by a user and having a secondary battery. Determining means for determining whether the received radio wave is the regular signal; and when the determination means determines that the received radio wave by the receiving means is not the regular signal, charging the secondary battery. The gist of the present invention is to provide a control means for shifting to a charging mode to be performed.

  According to this configuration, when a radio wave in a specific frequency band that can be received by the receiving unit and different from a regular signal, that is, a noise radio wave is received by the receiving unit, the portable device shifts to the charging mode. In this charging mode, the secondary battery included in the portable device is charged. The power obtained from the radio wave received by the receiving means during this charging mode is used as the power for charging the secondary battery, while the determination processing by the determining means is not performed during this charging mode. It is possible to take the following aspects. As described above, when the noise radio wave is received, the mode is shifted to the charging mode, and the received radio wave can be effectively used by dedicating the charging to the secondary battery.

  According to a second aspect of the present invention, in the portable device according to the first aspect of the present invention, charging using power obtained from radio waves received by the receiving means during the charging mode as power for charging the secondary battery. The gist is to further include means.

  According to this configuration, during the charging mode, the radio waves received by the receiving means are all used for charging the secondary battery regardless of whether or not it is a regular signal. Therefore, the secondary battery can be charged efficiently.

  According to a third aspect of the present invention, in the portable device according to the first or second aspect, a period during which the determination unit determines whether or not the radio wave received by the reception unit is the regular signal. The gist is defined as a determination period, and the control means shifts to the charging mode immediately after the determination period elapses.

  According to the configuration, as a result of the determination process performed by the determination unit within the determination period, when it is determined that the radio wave received by the reception unit is not a regular signal, that is, a noise radio wave, Switch to charge mode. For this reason, it is possible to start charging the secondary battery at an early stage while securing a period necessary for the determination process by the determination unit. Therefore, the power required for the determination process can be suppressed, and charging of the secondary battery can be ensured.

  According to a fourth aspect of the present invention, in the portable device according to any one of the first to third aspects, the mobile device further includes a transmission unit that transmits a response signal to the regular signal, and the control unit includes the control unit, The gist of the invention is that the charging mode is terminated before the normal signal is retransmitted from the communication partner of the portable device when a response signal to the normal signal is not transmitted by the transmission means. .

  According to this configuration, when the communication partner of the portable device cannot receive a response signal to the normal signal, when the normal signal is retransmitted, it is received by the receiving means of the portable device. In the stage before being performed, the charging mode is terminated. For this reason, by transmitting a response signal to the retransmitted normal signal, bidirectional communication is established between the portable device and the communication partner, and various operations based on the communication can be performed. Therefore, the charging of the secondary battery can be made suitable in consideration of bidirectional communication with the communication partner, and thus such a portable device is suitable for controlling the communication partner. Can do.

  According to a fifth aspect of the present invention, in the portable device according to the fourth aspect, the secondary battery further includes a primary battery that supplies power necessary for a main operation including a transmission process of the response signal by the transmission unit. The gist of the present invention is to supply electric power necessary for a sub operation different from the main operation.

  According to this configuration, the power required for the main operation, which is an essential operation for the operation of the portable device, is supplied from the primary battery, and the power required for the other sub-operations is supplied from the secondary battery. It has become. For this reason, adding a secondary battery can give added value to a portable device.

  According to the present invention, when a noise radio wave is received, the received radio wave can be effectively used.

Hereinafter, an embodiment embodying the present invention will be described.
As shown in FIG. 1, an electronic key system 1 is applied to the automobile of this embodiment. The electronic key system 1 includes a portable device 2 possessed by a vehicle owner and a security device 3 provided on the vehicle side, and bidirectional wireless communication between the portable device 2 and the security device 3 is possible. It is.

  The portable device 2 is roughly divided into a main function unit 11, a sub function unit 12, and a power supply function unit 13. First, the main function unit 11 includes a reception antenna 21, a reception circuit 22, a microcomputer 23, a transmission circuit 24, and a transmission antenna 25. The receiving antenna 21 is a medium for receiving radio waves in a specific frequency band (100 to 150 kHz in the present embodiment) including a request signal transmitted from the security device 3. The reception circuit 22 demodulates radio waves such as a request signal received by the reception antenna 21 to generate a reception signal and outputs the reception signal to the microcomputer 23.

  The microcomputer 23 includes a nonvolatile memory 23a, and an ID code (ID code of the portable device 2) set individually for each portable device 2 is stored in the memory 23a. When the reception signal is input from the reception circuit 22, the microcomputer 23 generates a response signal including the ID code of the portable device 2 and outputs the response signal to the transmission circuit 24 in order to respond to the request signal. The transmission circuit 24 modulates the response signal input from the microcomputer 23 into a radio wave having a predetermined frequency (300 MHz in this embodiment). The transmission antenna 25 is a medium for transmitting the response signal modulated by the transmission circuit 24.

  Next, the sub function unit 12 includes a vibrator 26 and a display 27. The vibrator 26 vibrates based on a control signal from the microcomputer 23, and the display 27 displays various information based on the control signal from the microcomputer 23.

  Next, the power supply function unit 13 includes a primary battery 28, a secondary battery 29, and a charging circuit 30. The primary battery 28 supplies power to the main function unit 11, the secondary battery 29 supplies power to the sub-function unit 12, and the charging circuit 30 is charged by the microcomputer 23 to charge the secondary battery 29. Is to do.

  The security device 3 includes a transmission circuit 31, a transmission antenna 32, a reception antenna 33, a reception circuit 34, and a verification device 35. The transmission circuit 31 modulates the request signal input from the verification device 35 into a radio wave having a predetermined frequency (134 kHz in this embodiment). The transmission antenna 32 is a medium for transmitting the request signal modulated by the transmission circuit 31.

  Here, the request signal transmitted from the transmission antenna 32 extends within a range of a radius of about 1 m centering on the door outside handle outside the vehicle. In FIG. 2, this area is indicated by a two-dot chain line as a predetermined area A32 outside the vehicle. In the predetermined area A32 outside the vehicle, bidirectional communication between the portable device 2 and the security device 3 is possible. That is, when the portable device 2 is brought into the predetermined area A32 outside the vehicle in a state where the request signal is transmitted in the predetermined area A32 outside the vehicle, the request signal is received by the portable device 2 and the portable device 2 2, a response signal is transmitted.

  Returning to FIG. 1, the receiving antenna 33 is a medium for receiving a response signal transmitted from the portable device 2 in response to the request signal. The reception circuit 34 demodulates the response signal received by the reception antenna 33 to generate a reception signal, and outputs the reception signal to the verification device 35.

  The verification device 35 includes a non-volatile memory 35a. In this memory 35a, the same ID code as the ID code of the portable device 2 (= regular portable device 2) adapted to the vehicle on which the security device 3 is mounted. (Reference ID code) is stored. The collating device 35 outputs a request signal to the transmission circuit 31 in a state where the door is locked in order to monitor the approach of the vehicle by the owner of the authorized portable device 2 (approach to the predetermined area A32 outside the vehicle). In other words, in this case, the collation device 35 executes vehicle exterior communication control. As a result, a request signal is transmitted from the transmission antenna 32 into the predetermined area A32 outside the vehicle. In addition, when the reception signal is input from the reception circuit 34 based on the vehicle communication control, the verification device 35 determines whether the ID code included in the reception signal matches the reference ID code. To do. That is, in this case, the collation device 35 performs ID code collation. Then, the collation device 35 recognizes that the legitimate portable device 2 has been used when both ID codes are matched by this ID code collation, and in this case, to allow the rider of the portable device 2 to get on. In addition, a door unlocking permission signal is output to the door control device 40. As a result, when the owner of the portable device 2 touches the door outside handle in the state where the unlocking of the door is permitted in this way, the door is unlocked by the door control device 40, thereby Boarding by the owner will be allowed.

  Next, the operation of the electronic key system 1 will be described. As described above, in wireless communication using the electronic key system 1, a request signal is transmitted from the security device 3 and a response signal is transmitted from the portable device 2. Here, as shown in FIG. 3A, the former request signal is composed of first to third signals A1 to A3, similar to the conventional request signal shown in FIG. As shown in (b), the latter response signal is composed of first to third response signals B1 to B3, similar to the conventional response signal shown in FIG. 5 (b). That is, first, the first signal A1 is intermittently transmitted in the predetermined area A32 outside the vehicle shown in FIG. 2 when the regular portable device 2 has not yet entered the predetermined area A32. In this state, when the owner of the authorized portable device 2 enters the predetermined area A32 outside the vehicle, the first signal A1 is received by the portable device 2, and the vehicle code included therein is the reference vehicle. When the code matches, the portable device 2 transmits the first response signal B1. When the first response signal B1 is received by the security device 3, the second signal A2 is transmitted from the security device 3. The second signal A2 is received by the portable device 2, and when the vehicle code included in the second signal A2 matches the reference vehicle code, the second response signal B2 is transmitted from the portable device 2. Then, when the second response signal B2 is received by the security device 3, the third signal A3 is transmitted from the security device 3. Then, when the third signal A3 is received by the portable device 2 and the challenge code included therein matches the reference challenge code, the third response signal B3 is transmitted from the portable device 2. When the third response signal B3 is received by the security device 3 and the ID code included therein matches the reference ID code, the door unlocking is permitted. This is the normal operation of the electronic key system 1.

  By the way, the portable device 2 provided for the electronic key system 1 can receive radio waves in a specific frequency band including a request signal (the request signal is a signal of 134 kHz and includes 100 to 150 kHz). Therefore, when the portable device 2 exists in a location different from the vehicle, and radio waves in the same frequency band different from the request signal are scattered there, the radio waves are received by the portable device 2. It is received by the antenna 21. When the reception signal is input from the reception circuit 22, the microcomputer 23 of the portable device 2 activates a timer to monitor the elapsed time from the first rise, and the received signal has a WAKE code that matches the reference WAKE code. Determine whether it is included.

  Here, if the received signal input from the receiving circuit 22 to the microcomputer 23 is related to the first signal A1 (regular signal) from the security device 3, the WAKE code included therein matches the reference WAKE code. Therefore, the first response signal B1 is transmitted from the portable device 2 following the normal operation described above. On the other hand, when the received signal input from the receiving circuit 22 to the microcomputer 23 is not related to the first signal A1 from the security device 3 but related to the noise signal shown in FIG. Are not included, the first response signal B1 is not transmitted from the portable device 2. In this case, the microcomputer 23 determines whether or not the WAKE code that matches the reference WAKE code is included in the received signal from the receiving circuit 22, with the period until the time measured by the timer reaches the cycle T1 + T2 as an upper limit. . When an affirmative determination is made within this period, the first response signal B1 is transmitted from the portable device 2 following the normal operation described above. On the other hand, when a negative determination is made within the period, the microcomputer 23 shifts the portable device 2 to the charging mode.

  In this charging mode, the microcomputer 23 stops the previous time counting by the timer, and monitors the elapsed time after shifting to the charging mode. In this charging mode, the determination operation related to the reference WAKE code is not performed, and the power obtained from the radio wave received by the receiving antenna 21 is used as the power for charging the secondary battery 29 through the charging circuit 30. Be devoted. Eventually, when the elapsed time after shifting to the charging mode reaches the timeout time Ts, the microcomputer 23 terminates the charging mode and shifts the portable device 2 to the standby mode in which the first signal A1 can be received. In this standby mode, when a reception signal is input from the reception circuit 22 to the microcomputer 23, the individual processing as described above is performed depending on whether the reception signal is related to the first signal A1 or a noise signal. (Decision processing / charging processing) is performed.

  Note that the method for determining whether the radio wave received by the receiving antenna 21 is a regular signal or a noise signal includes a WAKE code that matches the reference WAKE code in the received signal input from the receiving circuit 22 to the microcomputer 23. Instead of determining whether or not, the following may be performed. That is, when a reception signal is input from the reception circuit 22 to the microcomputer 23, the microcomputer 23 monitors the period from the first rising to the next rising.

  When the period coincides with the first period T1 (reference period) stored in advance in the memory 23a of the microcomputer 23 or is within the allowable range, the microcomputer 23 indicates that the reception radio wave from the receiving antenna 21 is the first It judges that it is signal A1, and transmits 1st response signal B1. Similarly, when the period until the next rising edge coincides with the second period T2 (third period T3) stored in advance in the memory 23a of the microcomputer 23 or is within the allowable range, the microcomputer 23 receives the signal. It is determined that the radio wave received by the antenna 21 is the second signal A2 (third signal A3), and the second response signal B2 (third response signal B3) is transmitted. The security device 3 that has received the third response signal B3 permits the unlocking of the door in the same manner as described above.

  On the other hand, as shown in FIG. 3C, when the period Tn1 from the rising edge of the first received signal (noise signal) to the next rising edge is outside the allowable range of the first period T1 (reference period), the microcomputer 23 determines that the first received signal is a noise radio wave. Next, even when the cycle Tn2 from the rise of the second received signal (noise radio wave) to the next rise is outside the allowable range of the second cycle T2 (reference cycle), the microcomputer 23 Is determined to be due to noise radio waves. Then, when a determination is made up to the period T1 + T2 shown in FIG. 3A, when a received signal having a period that coincides with the first period T1 or within the allowable range is not input, FIGS. ), The microcomputer 23 aborts the determination mode and shifts to the charging mode. This charging mode is terminated when the time before the first signal A1 is retransmitted, that is, when the elapsed time reaches the timeout time Ts, and the charging mode is shifted to the standby mode in which the first signal A1 can be received.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) When a radio wave in a specific frequency band including a request signal that can be received by the receiving antenna 21 and different from the first signal A1, that is, a noise radio wave is received by the receiving antenna 21, the portable device 2 is charged. Enter mode. In this charging mode, the secondary battery 29 provided in the portable device 2 is charged. And while using the electric power obtained from the radio wave received by the receiving antenna 21 during this charging mode as the electric power for charging the secondary battery 29, the determination process by the microcomputer 23 is not performed during this charging mode. I have to. As described above, when the noise radio wave is received, the mode is shifted to the charging mode, and the reception radio wave can be effectively used by dedicating the charging to the secondary battery 29 there.

  (2) In the charging mode, the radio waves received by the receiving antenna 21 are all used for charging the secondary battery 29 regardless of whether it is the first signal A1 or a noise signal. Therefore, the secondary battery 29 can be charged efficiently.

  (3) When it is determined that the received radio wave from the receiving antenna 21 is not the first signal A1, that is, the noise radio wave, as a result of the determination process performed by the microcomputer 23 during the determination mode, the portable device 2 Switch to charge mode. For this reason, it is possible to start charging the secondary battery 29 at an early stage while securing a period necessary for the determination process by the microcomputer 23. Therefore, the power required for the determination process can be suppressed, and charging of the secondary battery 29 can be ensured.

  (4) The security device 3 retransmits the first signal A1 when it cannot receive the first response signal B1 with respect to the first signal A1, but this is the receiving antenna 21 of the portable device 2. In the stage before being received at, the charging mode is terminated. For this reason, bidirectional communication is established between the portable device 2 and the security device 3 by transmitting the first response signal B1 to the retransmitted first signal A1. Operation is possible. Accordingly, the charging of the secondary battery 29 can be made suitable in consideration of bidirectional communication with the security device 3, and thus the portable device 2 is suitable for controlling the security device 3. It can be.

  (5) The power necessary for the operation of the main function unit 11 of the portable device 2 is provided from the primary battery 28, and the power necessary for the operation of the sub function unit 12 including the vibrator 26 and the display 27 is the secondary power. Power is supplied from the battery 29. For this reason, adding the secondary battery 29 can add value to the portable device 2. That is, the functions of the vibrator 26 and the display 27 that were difficult with only the primary battery 28 can be added. Further, even when the secondary battery 29 is exhausted, the main function unit 11 is operated by the primary battery 28, so that communication by the portable device 2 is possible.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, the sub function unit 12 includes additional functions such as the vibrator 26 and the display 27. However, the additional function is not limited to this, and a light emitting device or the like may be provided that notifies the user that the battery is charged, for example, by emitting light during charging. Further, the addition function can be omitted as appropriate. Any information may be displayed such as displaying the travel distance and repair history on the screen of the display 27.

  In the above embodiment, the timeout time Ts is set before the first signal A1 is retransmitted from the security device 3. However, this timeout time Ts can be set arbitrarily. For example, when it is desired to charge more power to the secondary battery, the timeout time Ts is set longer. In addition, when it is desired to terminate the charging mode and restart the determination at an early stage, the timeout time Ts is set short.

  In the above embodiment, the primary battery 28 supplies power to the main function unit 11 of the portable device 2, and the secondary battery 29 supplies power to the sub function unit 12 of the portable device 2. However, the voltage supply targets of the primary battery 28 and the secondary battery 29 can be changed. Specifically, for example, the secondary battery 29 may supply power to the main function unit 11, and the primary battery 28 may supply power to the sub function unit 12.

  Further, the voltage supply target of the primary battery 28 and the secondary battery 29 may not be determined. In this case, for example, when either the primary battery 28 or the secondary battery 29 is consumed, the other battery supplies the power for all operations of the portable device 2 in a complementary manner.

Furthermore, the voltage supply source of the portable device 2 may be configured only by the secondary battery 29. In this case, the secondary battery 29 provides power for all operations of the portable device 2.
In the above embodiment, the secondary battery 29 is charged by receiving the received radio wave. In addition, for example, a charging terminal that can be connected to an external power source is provided on the outer surface of the portable device 2 to You may make it charge by connecting the terminal for charge to a power supply.

  In the above embodiment, the first to third periods T1 to T3 have a function as a reference authentication code, and when a received radio wave that matches or is within an allowable range is detected, the received radio wave is the first To third signals A1 to A3. However, as shown in FIG. 3A, on-duty times T11 to T13 of the first to third signals A1 to A3 may be used as the reference authentication code. The collation may be performed by looking at both the first to third periods T1 to T3 and the on-duty times T11 to T13. Thereby, the determination accuracy of the received radio wave is further increased.

  In the above-described embodiment, when a reception signal having a period that coincides with the first period T1 or within the allowable range is not input even when the determination is performed up to the period T1 + T2, the microcomputer 23 aborts the determination mode, and the charge mode Had moved to. However, as shown in FIG. 4C, when the periods Tn1 and Tn2 of the first two received signals are outside the allowable range of the first period T1, it is determined as a noise signal, and FIG. As shown in d) to (e), the charging mode may be shifted to an early point when the cycle becomes Tn1 + Tn2. Thereby, in the case of receiving a noise radio wave with a short cycle, it is possible to shift to the charging mode at an early stage. FIGS. 4A and 4B are the same as FIGS. 3A and 3B described above.

  In the above-described embodiment, after shifting to the determination mode, determination is performed until the cycle T1 + T2 (period time), and when it is determined that the received radio wave is a noise signal, the charging mode is shifted. However, in the determination mode, it is possible to change how long the determination is performed. For example, when it is desired to charge more power, the determination mode is set to the first period T1, and the charging mode is immediately shifted to an early time when it is determined that the first period T1 is different from the period Tn1 of the first reception signal. . On the other hand, when it is desired to increase the accuracy of the determination, the determination may be performed after the cycle T1 + T2, for example, the cycle T1 + T2 + T3.

  Further, when the determination is made based on the on-duty times T11 to T13, it is determined that the received radio wave is a noise signal when the on-duty time of the received radio wave is different from the on-duty time T11 of the first signal A1. Thus, the charging mode may be shifted to the early stage.

The block diagram which shows the structure of the motor vehicle of this embodiment to which the electronic key system is applied. Explanatory drawing which shows the predetermined area | region outside a vehicle, The perspective view of a portable machine is in the expanded circle. In this embodiment, (a) is a waveform diagram of a request signal, (b) is a waveform diagram of a response signal, (c) is a waveform diagram of a noise signal, (d) is a state diagram of ON / OFF of a determination mode, e) is a state diagram of on / off of the charging mode. In another embodiment, (a) is a waveform diagram of a request signal, (b) is a waveform diagram of a response signal, (c) is a waveform diagram of a noise signal, (d) is an on / off state diagram of a determination mode, (E) is a state diagram of charging mode on / off. In the prior art, (a) is a waveform diagram of a request signal, (b) is a waveform diagram of a response signal, and (c) is a waveform diagram of a noise signal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 2 ... Portable machine, 3 ... Security apparatus (communication partner), 11 ... Main function part, 12 ... Sub function part, 21 ... Reception antenna (reception means), 22 ... Reception circuit (reception means) , 23 ... microcomputer (determination means, control means), 24 ... transmission circuit (transmission means), 25 ... transmission antenna (transmission means), 28 ... primary battery, 29 ... secondary battery, 30 ... charging circuit section (charging means) , A1 to A3... First to third signals, B1 to B3... First to third response signals.

Claims (5)

In a portable device that the user has and has a secondary battery,
Receiving means for receiving radio waves in a specific frequency band including a regular signal suitable for the portable device;
Determining means for determining whether or not the received radio wave by the receiving means is the regular signal;
Control means for shifting to a charging mode for charging the secondary battery when the determination means determines that the radio wave received by the reception means is not the regular signal. The portable device according to claim 1,
A portable device, further comprising: a charging unit that uses power obtained from the radio wave received by the receiving unit during the charging mode as power for charging the secondary battery. The determination unit defines a period during which it is determined whether the received radio wave from the reception unit is the regular signal as a determination period,
The portable device according to claim 1, wherein the control unit shifts to the charging mode immediately after the determination period has elapsed. In the portable machine as described in any one of Claims 1-3,
A transmission means for transmitting a response signal to the regular signal;
The control unit terminates the charging mode at a stage before the regular signal is retransmitted from the communication partner of the portable device when a response signal to the regular signal is not transmitted by the transmission unit. A portable device characterized by that. The portable device according to claim 4, wherein
A primary battery that supplies power necessary for a main operation including transmission processing of the response signal by the transmission unit;
The secondary battery supplies power necessary for a sub operation different from the main operation.

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