JP2014082643A - Portable electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the possibility that a proximity communication function comes into proper action.SOLUTION: The portable electronic apparatus 11 includes: a battery 131; a proximity communication section 110; a storage section 122 that stores information used when the proximity communication section 110 communicates; and a delay circuit 172 that makes the timing that power supply from the battery 131 to the proximity communication section 110 is started different from the timing that power supply from the battery 131 to the storage section 122 is started.

Description

  The present application relates to a portable electronic device having a proximity communication function.

  Devices having a near field communication function are known. For example, in Patent Document 1, only when the necessary power supply from the battery is lost, the security controller is controlled to a mode that operates with low power consumption, and contactless authentication and settlement functions are ensured by external electromagnetic field power. Mobile communication terminal devices have been proposed.

JP 2011-035749 A

  In devices with a proximity communication function, when power supply to multiple parts starts almost simultaneously, the operation of the communication unit, storage unit, etc. related to the proximity communication function becomes unstable due to a temporary drop in battery voltage As a result, the near field communication function may not operate normally. From the above, there is a need for a portable electronic device that can increase the possibility that the near field communication function operates normally.

  In one aspect, the portable electronic device has a battery, a proximity communication unit, a storage unit that stores information used when the proximity communication unit communicates, and power supply from the battery to the proximity communication unit is started. And a circuit for differentiating the timing at which power supply from the battery to the storage unit is started.

FIG. 1 is a block diagram illustrating a configuration of the portable electronic device according to the first embodiment. FIG. 2 is a flowchart showing the operation of the low voltage detection unit. FIG. 3 is a diagram illustrating an example of a voltage drop when the proximity communication unit is activated when the delay circuit is not provided. FIG. 4 is a diagram illustrating an example of a voltage drop when the proximity communication unit is activated when a delay circuit is provided. FIG. 5 is a block diagram illustrating a configuration of a portable electronic device according to the second embodiment. FIG. 6 is a diagram illustrating an example of an operation cycle. FIG. 7 is a flowchart showing the operation of the control unit.

  Embodiments for carrying out the present invention will be described in detail with reference to the drawings. Hereinafter, a mobile phone will be described as an example of the mobile electronic device.

(Embodiment 1)
The configuration of the portable electronic device 11 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the portable electronic device 11. The mobile electronic device 11 is a mobile phone having a proximity communication function. As shown in FIG. 1, the mobile electronic device 11 includes a proximity communication unit 110, secure areas (storage units) 121 and 122, a battery 131, a control unit 141, a power management unit 142, and a lock holding unit 143. , Low voltage detector 144, communication unit 151, camera 152, low loss regulators 161 and 162, and delay circuits 171 and 172. The mobile electronic device 11 may include other elements included in a general mobile phone.

  The proximity communication unit 110 realizes proximity communication (non-contact communication). Proximity communication is communication performed at a short distance of about several centimeters to 1 meter. Technologies for realizing the near field communication include, for example, a technology whose specifications are formulated in an NFC (Near Field Communication) forum, other RFID (Radio Frequency IDentification) technology, and the like. The proximity communication unit 110 performs communication by electromagnetic induction, for example. The near field communication unit 110 may be configured to perform near field communication even when the power source of the portable electronic device 11 is OFF (when other function units such as the control unit 141 are stopped).

  Proximity communication unit 110 includes a baseband processing unit 111, a detection circuit 112, an antenna 113, and a switch 114. The baseband processing unit 111 controls the proximity communication unit 110. The baseband processing unit 111 has a function of controlling the switch 114 in addition to a function of performing various signal processing for near field communication such as baseband processing. The detection circuit 112 detects reception of a signal by the antenna 113. The antenna 113 transmits / receives a signal to / from another device that supports proximity communication such as the device 20. The device 20 is, for example, a reader, a writer, or a reader / writer. The switch 114 sets or releases the lock of the proximity communication unit 110. When the lock is set, the near field communication unit 110 does not perform near field communication and does not access (read / write) the secure areas 121 and 122.

  The secure areas 121 and 122 store signals (information exchanged by proximity communication) used when the proximity communication unit 110 communicates. The information stored in the secure areas 121 and 122 includes, for example, information for authentication and information for determination. The information stored in the secure areas 121 and 122 is safely protected by, for example, encryption technology. The secure areas 121 and 122 may be provided in different places. Each of the secure areas 121 and 122 is provided in any location such as a storage device dedicated to proximity communication, a SIM (Subscriber Identity Module) card, a main body memory used for storing various applications and data, and a removable memory card. May be.

  The battery 131 supplies power to each part of the portable electronic device 11. The battery 131 may be rechargeable. The battery 131 may be removable.

  The control unit 141 controls the mobile electronic device 11 as a whole. The control unit 141 includes an arithmetic processing device for executing various controls. The arithmetic processing unit includes, for example, a CPU (Central Processing Unit), an SoC (System-on-a-chip), an MCU (Micro Control Unit), and an FPGA (Field-Programmable Gate Array), but is not limited thereto.

  The power management unit 142 manages the power supply to each unit so that the power of the battery 131 is efficiently used and lasts long. The power management unit 142 may have a function of managing charging of the battery 131.

  The lock holding unit 143 holds the lock of the proximity communication unit 110. Specifically, when the control unit 141 instructs the lock holding unit 143 to lock the proximity communication unit 110, the lock holding unit 143 starts sending a signal instructing the baseband processing unit 111 to lock the proximity communication unit 110. . When the controller 141 is instructed to unlock the proximity communication unit 110, the lock holding unit 143 stops sending a signal instructing to lock the proximity communication unit 110. The instruction from the control unit 141 to the lock holding unit 143 is executed, for example, in response to a user operation that instructs to enable or disable the near field communication function.

  The low voltage detection unit 144 controls access to the secure areas 121 and 122 by the proximity communication unit 110 based on the voltage of the power B1 supplied from the battery 131 (hereinafter referred to as “battery voltage”). Specifically, the low voltage detection unit 144 determines whether the battery voltage is lower than a threshold value. When the battery voltage is lower than the threshold value, the low voltage detection unit 144 sends a signal that instructs the baseband processing unit 111 to lock the proximity communication unit 110. When the battery voltage is not lower than the threshold value, the low voltage detection unit 144 does not send a signal that instructs the proximity communication unit 110 to be locked to the baseband processing unit 111. The threshold used by the low voltage detection unit 144 for comparison with the battery voltage is a voltage at which the proximity communication unit 110 and the secure areas 121 and 122 operate stably (hereinafter referred to as “required operation voltage”).

  When the remaining amount of the battery 131 decreases and the battery voltage falls below the required operating voltage, there is a possibility that a failure such as the baseband processing unit 111 not being able to normally access the secure area 121 or 122 may occur. Even when a load such as the communication unit 151 operates when the remaining amount of the battery 131 is decreasing, the battery voltage temporarily falls below the required operating voltage, and the baseband processing unit 111 is normal to the secure area 121 or 122. Failures such as inaccessibility may occur. Since the low voltage detection unit 144 locks the proximity communication unit 110 before the battery voltage falls below the required operating voltage, the possibility of such a failure occurring can be reduced.

  When the portable electronic device 11 is configured to be able to perform proximity communication even when the power is off, the power of the battery 131 is consumed due to the use of dark current or proximity communication even when the power is off. The battery voltage may be lower than the required operating voltage. Therefore, when such a configuration is adopted, the low voltage detection unit 144 is configured to operate at least until the battery voltage falls below the required operating voltage even when the power is turned off.

  The communication unit 151 performs wireless communication with a base station of a communication carrier. Communication methods supported by the communication unit 151 include, for example, LTE (Long Term Evolution), W-CDMA (Wideband Code Division Multiple Access), CDMA2000, PDC (Personal Digital Cellular), GSM (registered trademark) (Global System for Mobile Communications). ), PHS (Personal Handy-phone System), WiMAX (Worldwide Interoperability for Microwave Access), and the like. The communication unit 151 may support a communication method in which communication is performed at a relatively short distance, such as IEEE 802.11 and Bluetooth (registered trademark). The communication unit 151 may support a plurality of communication methods.

  The camera 152 electronically acquires an image in the shooting range. The communication unit 151 and the camera 152 are loads that consume the power of the battery 131.

  Low drop out regulators 161 and 162 convert the voltage of the power supplied from the battery 131 into a voltage at which the proximity communication unit 110 and the secure areas 121 and 122 operate. The low-loss regulator 161 supplies the converted power P1 to the near field communication unit 110 and the secure area 121. The low loss regulator 162 supplies the converted power P2 to the secure region 122. The power supply by the low-loss regulators 161 and 162 is performed while a signal indicating that the detection circuit 112 is detecting a signal (hereinafter referred to as “detection signal”) is input to the low-loss regulators 161 and 162, that is, , While close proximity communication is possible.

  The delay circuit 171 delays the detection signal transmitted from the detection circuit 112. The detection signal delayed by the delay circuit 171 is output to the low loss regulator 161 and the delay circuit 172. The delay circuit 172 further delays the detection signal input from the delay circuit 171. The detection signal delayed by the delay circuit 172 is output to the low loss regulator 162.

  Thus, when the delay circuit 171 delays the detection signal, the timing at which the supply of the power P1 to the near field communication unit 110 and the secure area 121 is slightly delayed from the timing at which the detection circuit 112 detects the signal. In addition, when the delay circuit 172 delays the detection signal, the timing at which the supply of the power P2 to the secure region 122 is started is further delayed.

  When power supply to the near field communication unit 110 and the secure areas 121 and 122 is started, the battery voltage may temporarily decrease due to the inrush current. For this reason, there is a possibility that the battery voltage temporarily falls below the required operating voltage, causing a failure such that the baseband processing unit 111 cannot normally access the secure area 121 or 122. Such a situation is likely to occur when the remaining amount of the battery 131 is relatively low.

  By delaying the timing at which power supply to the secure area 122 is started by the delay circuit 172 from the timing at which power supply to the proximity communication unit 110 and the secure area 121 is started, the inrush current can be dispersed. . Furthermore, the delay circuit 171 delays the timing at which power supply to the proximity communication unit 110 and the secure area 121 is started from the timing at which the detection circuit 112 detects a signal, thereby The input can be made more gradual. As a result, the decrease in battery voltage due to the inrush current is reduced, and the possibility that a failure will occur can be reduced.

  The operation of the low voltage detection unit 144 will be described with reference to FIG. FIG. 2 is a flowchart showing the operation of the low voltage detection unit 144. The low voltage detection unit 144 repeatedly executes the operation shown in FIG.

  As shown in FIG. 2, when the battery voltage is lower than the threshold value (Yes at Step S101), the low voltage detection unit 144 turns on the output (Step S102). The fact that the output of the low voltage detection unit 144 is ON means that the lock instruction is issued from the low voltage detection unit 144 to the proximity communication unit 110.

  When the battery voltage is not lower than the threshold value (No at Step S101), the low voltage detection unit 144 turns off the output (Step S103). That the output of the low voltage detection unit 144 is OFF means that the low voltage detection unit 144 does not instruct the proximity communication unit 110 to lock. Even in this case, the lock holding unit 143 may instruct the proximity communication unit 110 to lock.

  The effects of the embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram illustrating an example of a voltage drop when the proximity communication unit 110 is activated when the delay circuit 172 is not provided. FIG. 4 is a diagram illustrating an example of a voltage drop when the proximity communication unit 110 is activated when the delay circuit 172 is provided. 3 and 4, current A is the current value of power P <b> 1 supplied from the low loss regulator 161 to the proximity communication unit 110 and the secure area 121, and current B is supplied from the low loss regulator 162 to the secure area 122. This is the current value of the power P2 to be performed.

  In the example shown in FIG. 3, the interval of the inrush current is only about 4 μs, so the voltage of the power P2 is greatly reduced. As a result, there is a possibility that the baseband processing unit 111 may fail such as being unable to normally access the secure area 122 to which the power P2 is supplied. As a specific example, for example, when the voltage of the power P <b> 2 supplied to the secure area 122 decreases, the voltage of the signal transmitted from the secure area 122 to the baseband processing unit 111 may also decrease. Therefore, even if the secure region 122 intends to send a signal to the baseband processing unit 111, the baseband processing unit 111 may not be able to detect because the voltage of the signal is low. In this way, there is a possibility that a failure that the baseband processing unit 111 cannot normally access the secure area 122 occurs.

  On the other hand, in the example shown in FIG. 4, the delay circuit 172 extends the interval at which the inrush current flows to 82.5 μs. For this reason, the voltage drop of the electric power P2 is reduced compared with the case of FIG. As a result, the possibility that a failure related to the secure area 122 to which the power P2 is supplied is low.

  As described above, the portable electronic device 11 detects the decrease in the battery voltage by the low voltage detection unit 144. For this reason, the portable electronic device 11 may lock the proximity communication unit 110 and the secure areas 121 and 122 before the remaining amount of the battery 131 decreases until the battery voltage falls below the required operating voltage, and a failure may occur. Can be lowered. Furthermore, the portable electronic device 11 uses the delay circuits 171 and 172 to distribute the inrush current when power supply is started to the proximity communication unit 110 and the secure areas 121 and 122. For this reason, even before the remaining amount of the battery 131 decreases until the battery voltage falls below the required operating voltage, the portable electronic device 11 suppresses a temporary decrease in the battery voltage and reduces the possibility of a failure. be able to.

  In the above-described embodiment, the case where the voltage of the power P2 is reduced has been described. However, the embodiment is not limited to this. For example, a decrease in the voltage of the power P1 can be reduced by the same method. In this case, the signal transmitted from the baseband processing unit 111 to the secure area 122 may not be detected by the secure area 122. Can be lowered.

(Embodiment 2)
Another embodiment will be described. FIG. 5 is a block diagram showing a configuration of the portable electronic device 12. The portable electronic device 12 is different from the portable electronic device 11 in that it further includes a secure area (storage unit) 123, a low-loss regulator 163, a delay circuit 173, and a signal line L1.

  The secure area 123 stores a signal (information exchanged by proximity communication) used when the proximity communication unit 110 communicates. The information stored in the secure area 123 includes, for example, information for authentication and information for determination. The information stored in the secure area 123 is safely protected by an encryption technique, for example. The secure area 123 may be provided in any location such as a storage device dedicated to near field communication, a SIM card, a main body memory used for storing various applications and data, and a removable memory card.

  The low-loss regulator 163 converts the voltage of the power supplied from the battery 131 into a voltage at which the secure area 123 operates, and supplies the converted power P3 to the secure area 123. The power supply by the low loss regulator 163 is performed while the detection signal transmitted from the detection circuit 112 is input to the low loss regulator 163, that is, while proximity communication is possible.

  The detection signal sent from the detection circuit 112 and delayed by the delay circuit 171 and the delay circuit 172 is input to the delay circuit 173. The delay circuit 173 further delays the detection signal input from the delay circuit 172. The detection signal delayed by the delay circuit 173 is output to the low loss regulator 163. As described above, the delay circuit 173 delays the detection signal, whereby the timing at which the supply of the power P3 to the secure area 123 is started is further delayed than the timing at which the supply of the power P2 to the secure area 122 is started. .

  By delaying the timing at which power supply to the secure region 123 is started by the delay circuit 173 from the timing at which power supply to the secure region 122 is started, the inrush current can be distributed. That is, in the portable electronic device 12, power supply to the secure area 122 is started with a delay of the delay by the delay circuit 172 after power supply to the proximity communication unit 110 and the secure area 121 is started. Thereafter, power supply to the secure area 123 is started with a delay by the delay by the delay circuit 173.

  In the mobile electronic device 12, since the secure area 123 has increased, the total amount of inrush current when starting proximity communication has increased, but the delay circuit 173 delays the timing at which the increased amount of inrush current occurs. Has been. For this reason, inrush current is dispersed, and a decrease in battery voltage due to the inrush current is reduced. As a result, the possibility of a failure due to a temporary decrease in battery voltage is low.

  In this way, even if the number of secure areas increases, by increasing the number of delay circuits, the inrush current at the time of starting proximity communication is distributed, and the possibility of a failure due to a temporary drop in battery voltage is reduced. be able to.

  The signal line L1 transmits an instruction from the control unit 141 toward the baseband processing unit 111. Specifically, in the portable electronic device 12, the control unit 141 monitors the operation status of loads other than the proximity communication unit 110 and the secure areas 121 to 123. When there is a high possibility that the battery voltage will decrease, the control unit 141 sends a signal that instructs the baseband processing unit 111 to lock the proximity communication unit 110 via the signal line L1.

  For example, as shown in FIG. 6, the operation for the communication unit 151 to communicate with the base station has an operation cycle. This operation cycle becomes longer when the frequency of communication is low, such as in a standby state, and becomes shorter when a large amount of information is transmitted / received during a call. When a load such as the communication unit 151 starts operation, an inrush current is generated, and a failure due to a temporary decrease in battery voltage may occur.

  Therefore, when the operation cycle of the load such as the communication unit 151 is shorter than the minimum reference cycle, the control unit 141 sends a signal instructing the proximity communication unit 110 to be locked to the baseband processing unit 111. As a result, the possibility of a failure due to a temporary drop in battery voltage can be reduced.

  For example, the minimum reference period is set sufficiently longer than the time required to read / write information from / to the secure areas 121-123. With such a setting, the possibility of a failure that prevents normal access to the secure areas 121 to 123 can be reduced. The minimum reference period may be different for each load to be monitored. The operation period compared with the lowest reference period may be a statistical value such as an average value, median value, maximum value, minimum value, etc. of the most recent predetermined number of operation periods.

  The control unit 141 predicts the next timing when the load operates based on the operation cycle, and when the period from the present to the predicted timing is shorter than the threshold, the control unit 141 determines whether the proximity communication unit 110 A signal instructing locking may be sent. The threshold is, for example, a time sufficiently longer than the time required to read / write information from / to the secure areas 121-123. That is, the control unit 141 may allow the operation of the proximity communication unit 110 only when it is determined that there is sufficient time before the inrush current is generated due to the start of the load operation. With such a configuration, it is possible to further reduce the possibility of a failure due to a temporary decrease in battery voltage.

  The operation of the control unit 141 will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the control unit 141. The control unit 141 repeatedly executes the operation shown in FIG. The control unit 141 may execute other operations in parallel with the operation illustrated in FIG.

  As shown in FIG. 7, when the operation cycle is shorter than the minimum reference cycle (step S201, Yes), the control unit 141 turns on the output to the baseband processing unit 111 (step S202). That the control unit 141 turns on the output to the baseband processing unit 111 means that the control unit 141 issues a lock instruction to the near field communication unit 110.

  When the operation cycle is not shorter than the minimum reference cycle (No at Step S201), the control unit 141 turns off the output to the baseband processing unit 111 (Step S203). That the control unit 141 turns off the output to the baseband processing unit 111 means that the control unit 141 does not instruct the proximity communication unit 110 to lock. Even in this case, the lock holding unit 143 or the low voltage detection unit 144 may be instructed to lock the proximity communication unit 110.

  As described above, by increasing the number of delay circuits in accordance with the number of secure areas, even if the secure areas increase, it is possible to disperse the inrush current and reduce the possibility of failure. In addition, the control unit 141 monitors the operation status of loads other than the proximity communication unit 110 and the secure areas 121 to 123, and locks the proximity communication unit 110 when the operation cycle is shorter than the minimum reference cycle. Such control can also suppress a temporary decrease in battery voltage and reduce the possibility of a failure.

  Embodiment which this application discloses can be changed in the range which does not deviate from the summary and range of invention. Furthermore, the embodiment disclosed in the present application and its modifications can be combined as appropriate.

  In the above-described embodiment, power is supplied in the order of the secure area 121 (P1), the secure area 122 (P2), and the secure area 123 (P3). However, the embodiment is not limited to this.

  For example, the delay circuit 171, the delay circuit 172, and the delay circuit 173 are configured by one delay control unit including three signal output units without being configured by separate discrete semiconductors as shown in FIG. When starting proximity communication with the portable electronic device 12, the portable electronic device 12 is requested to communicate with any secure region among the secure region 121, the secure region 122, and the secure region 123. There may be.

  With this configuration, the delay control unit that has received a request for communication with any secure region from the device 20 via the baseband processing unit 111 supplies power to the secure region corresponding to the request. First output a signal to the low loss regulator.

  That is, for example, when the device 20 requests communication based on the information stored in the secure area 123 when the proximity communication is started, the delay control unit first requests the low loss regulator 163 in response to the request. Can output power (P3) to the secure area 123 at an earlier timing than the secure area 121 and the secure area 122.

  In this way, in response to a request from the device 20, the delay control unit may be able to change the order of power supply to the secure area, in other words, the order of delay in supplying power.

  In the above embodiment, a mobile phone has been described as an example of the mobile electronic device, but the device according to the appended claims is not limited to the mobile phone. The device according to the appended claims may be a mobile electronic device other than a mobile phone. Examples of the portable electronic device include, but are not limited to, a tablet, a portable personal computer, a digital camera, a media player, an electronic book reader, a navigator, and a game machine.

  The characterizing embodiments have been described in order to fully and clearly disclose the technology according to the appended claims. However, the appended claims should not be limited to the above-described embodiments, but all modifications and alternatives that can be created by those skilled in the art within the scope of the basic matters shown in this specification. Should be configured to embody such a configuration.

11, 12 Portable electronic device 110 Proximity communication unit 111 Baseband processing unit 112 Detection circuit 113 Antenna 114 Switches 121 to 123 Secure area (storage unit)
131 Battery 141 Control Unit 142 Power Management Unit 143 Lock Holding Unit 144 Low Voltage Detection Unit 151 Communication Unit 152 Camera 161 to 163 Low Loss Regulator 171 to 173 Delay Circuit 20 Device

Claims (1)

Battery,
Proximity communication unit,
A storage unit for storing information used when the proximity communication unit communicates;
A circuit for differentiating a timing at which power supply from the battery is started to the proximity communication unit and a timing at which power supply is started from the battery to the storage unit;
A portable electronic device comprising:

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