JP2016091364A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus capable of preventing a fault caused by a foreign matter existing between the contour of a connector and a power terminal.SOLUTION: An electronic apparatus includes a connector for connecting to an external device. The connector includes a power terminal, a ground terminal, and a conductive contour section forming contour of the connector. The electronic apparatus further includes a detector for detecting electrostatic capacitance between the contour section and a ground electrode, a determination section for determining whether a foreign matter exists between the contour section and the power terminal on the basis of the detected electrostatic capacitance, and a notification section for notifying existence of the foreign matter on the basis of determination results by the determination section.SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to an electronic device having a connector.

  2. Description of the Related Art Conventionally, portable electronic devices such as mobile phones have been widely used, and small secondary batteries (storage batteries) are often used as power sources for these electronic devices. Such charging of the secondary battery is often performed by connecting an AC adapter to the electronic device and using a charging circuit in the electronic device. As a standard for connecting an external peripheral device such as an AC (Alternating Current) adapter to an electronic device, a USB (Universal Serial Bus) standard is widely used.

  The USB standard employs a method called a bus powered method that allows power supply from the host. In the USB interface, overcurrent protection of a device by reverse insertion of a connector or unexpected power supply short-circuit is defined as a role on the host side, and usually an overcurrent protection mechanism is mounted on the host side. However, on the market, there are USB hosts that do not implement these mechanisms and USB cables that have wiring errors. There has been disclosed a technique for notifying a user when an overcurrent flows using such a USB host and a USB cable.

  For example, Japanese Patent Laying-Open No. 2006-48594 (Patent Document 1) discloses a USB device device including a communication unit that performs data communication with a host unit via a USB cable. The USB device device includes an overcurrent prevention unit, an overcurrent state detection unit, and an overcurrent state notification unit in the signal line and the power line. Even if a USB cable with a wiring mistake, a connection error of a signal line or a power line in the host means, or an unexpected signal short-circuit occurs, the USB device apparatus is provided with an overload on the USB device apparatus side. The current state detecting means and the overcurrent state notifying means can notify the user of an abnormal connection state.

  Japanese Patent Laying-Open No. 2010-130255 (Patent Document 2) discloses an electronic device that controls the shutoff of a power supply in accordance with a wet state.

JP 2006-48594 A JP 2010-130255 A

  In recent years, portable electronic devices such as mobile phones have been miniaturized, and there are many cases where the plug shape of the USB connector is such that the distance between the terminal and the outer ground (metal case) is narrow, such as microUSB. ing. Along with this, there are increasing cases of short-circuiting due to adhesion of foreign matter (for example, water) between the terminal of the connector and the outer ground.

  The technique of Patent Document 1 is configured to detect an overcurrent state when power is supplied from the USB host to the USB device side via a USB cable. In other words, it is not possible to prevent defects in electronic equipment due to the presence of foreign matter. The technique of Patent Document 2 is configured to prevent a short circuit of the circuit due to, for example, a circuit board in an electronic device getting wet with water, but detects the presence of foreign matter inside the connector. It's not technology.

  The present disclosure has been made in order to solve the above-described problems, and an object in one aspect is to prevent a problem due to the presence of a foreign object between the outer shell of the connector and the power supply terminal. It is to provide possible electronic devices.

  An electronic device according to an embodiment includes a connector for connecting to an external device. The connector includes a power terminal, a ground terminal, and a conductive outer portion that forms an outer portion of the connector. The electronic device detects whether or not there is a foreign object between the outer portion and the power supply terminal based on the detected electrostatic capacitance between the outer portion and the ground electrode. And a notification unit that notifies the presence of the foreign object based on the determination result of the determination unit.

  According to the present disclosure, it is possible to prevent a problem due to the presence of foreign matter between the outer shell of the connector and the power supply terminal.

It is the schematic which shows the whole structure of the electronic device of a comparative example. It is the schematic for demonstrating the whole structure of the electronic device according to this Embodiment. It is a figure for demonstrating the foreign material detection system according to this Embodiment. It is a figure which shows the structure which connected the AC adapter to the electronic device according to this Embodiment. It is a block diagram which shows the hardware constitutions of the electronic device according to this Embodiment. It is a functional block diagram of the electronic device according to this Embodiment. It is a flowchart which shows the process sequence of the foreign material detection which the electronic device according to this Embodiment performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<Comparative example>
First, an outline of the overall configuration of an electronic device 1000 of a comparative example for comparison with the electronic device according to the embodiment of the present invention will be described.

FIG. 1 is a schematic diagram illustrating an overall configuration of an electronic apparatus 1000 of a comparative example.
Referring to FIG. 1, electronic device 1000 includes a CPU (Central Processing Unit) 1100, a charging circuit 1200, and a USB connector 1300. Here, it is assumed that the electronic device 1000 is supplied with power from the power source 22 of the AC adapter 20 on the USB host side via the AC adapter cable 24.

  Here, a conductive outer portion 1400, which is a metal case forming the outer shell of the USB connector 1300, is grounded to release static electricity, and the GND (ground) of the board on which the electronic components constituting the electronic device 1000 are mounted. ) It is connected to the electrode. For example, the outer portion 1400 is connected to the GND electrode of the board on which the USB connector 1300 is mounted. In such an electronic device 1000, in a state where foreign matter (for example, water) adheres between the VBUS terminal and the outer portion 1400 and the VBUS terminal and the outer portion 1400 are short-circuited, the electronic device 1000 and the AC adapter 20 Is connected, an overcurrent flows through the path as shown in FIG. 1, and a problem such as heat generation occurs.

  As described above, an overcurrent protection mechanism is usually mounted on the host side. Therefore, the AC adapter 20 on the USB host side can detect an overcurrent greater than a predetermined value (hereinafter also referred to as “predetermined value”) by the overcurrent protection mechanism. In other words, the AC adapter 20 cannot detect the current as an overcurrent until a current of a predetermined value or more flows. This predetermined value is predetermined on the AC adapter 20 side, and is assumed to be 2.1 A for an AC adapter of 5 V, 1.8 A specifications, for example.

  Here, when the outer portion 1400 and the VBUS terminal (power supply terminal) are in an incomplete short circuit state (half short state) with a small resistance, a current less than a predetermined value (less than 2.1 A in the above example) is It may flow along a route as shown in FIG. In such a case, the overcurrent protection mechanism by the AC adapter 20 does not work, and the electronic device 1000 continues to be supplied with a current less than the predetermined value from the AC adapter 20. Therefore, there is a possibility that problems such as melting occur in the housing of the electronic device 1000.

<Overall configuration>
Next, the overall configuration of electronic device 10 according to the present embodiment will be described.

  FIG. 2 is a schematic diagram for illustrating the overall configuration of electronic apparatus 10 according to the present embodiment. Although the following description demonstrates the case where the electronic device 10 is a smart phone, it is realizable as arbitrary apparatuses. For example, the electronic device 10 can be realized as a mobile phone, a tablet electronic device, a PDA (Personal Digital Assistance), a PC (Personal Computer), or the like.

  Referring to FIG. 2, electronic device 10 can receive power supplied from AC adapter 20 shown in FIG. 1 via USB connector 116. The external power source that supplies power to the electronic device 10 is not limited to the AC adapter 20, and may be a PC, a portable battery, or the like, for example.

  The outer portion 172 is a conductive metal case that forms an outer portion of the USB connector 116. The outer portion 172 is connected via a switch 156 to the GND electrode of the substrate on which the electronic components constituting the electronic device 10 are mounted. For example, the outer portion 172 is connected to the GND electrode of the substrate on which the USB connector 116 is mounted via the switch 156.

  The switch 156 is provided between the outer portion 172 and the GND electrode. A CPU (Central Processing Unit) 102 controls connection between the outer portion 172 and the GND electrode by controlling opening and closing of the switch 156.

  A measurement circuit 120 is provided between the outer portion 172 and the switch 156. For example, the measurement circuit 120 measures a change in capacitance caused by the presence of foreign matter (mixing or adhesion) between the outer portion 172 and the VBUS terminal.

  FIG. 3 is a diagram for describing a foreign object detection method according to the present embodiment. Referring to FIG. 3, CPU 102 and measurement circuit 120 are configured to be able to communicate with each other, and perform serial communication, for example.

  The capacitor 132 is used for detecting foreign matter, and is connected between the measurement circuit 120 and the GND electrode. Capacitance C1 indicates the capacitance between the outer portion 172 and the VBUS terminal. Capacitance C2 indicates a capacitance newly generated between the outer portion 172 and the VBUS terminal due to the presence of foreign matter. Specifically, when no foreign matter exists between the outer portion 172 and the VBUS terminal, the capacitance between the outer portion 172 and the VBUS terminal is C1, and when the foreign matter is present, the outer portion The capacitance between 172 and the VBUS terminal is C1 + C2. That is, the electrostatic capacity when foreign matter exists between the outer portion 172 and the VBUS terminal is larger than the electrostatic capacity when no foreign matter exists.

  The CPU 102 executes the following processing at a predetermined detection timing (for example, every 10 seconds). First, the CPU 102 turns off the switch 156. The CPU 102 detects a change in capacitance between the outer portion 172 and the VBUS terminal using the measurement circuit 120.

  Specifically, the measurement circuit 120 charges the capacitor 132 with the power of the storage battery 124 in accordance with an instruction from the CPU 102. When the capacitor 132 is fully charged, the measurement circuit 120 discharges the power charged in the capacitor 132 via the resistor R in the direction of the arrow in FIG. 3 (between the outer portion 172 and the VBUS terminal). When the discharge is completed, the measurement circuit 120 interrupts and inputs a signal indicating a time (discharge time) from the start of the discharge to the end of the discharge to the CPU 102 (for example, PORT_A). Note that the state of charge of the capacitor 132 can be grasped, for example, by measuring the voltage of the capacitor 132 using a voltage sensor or the like.

  The CPU 102 can detect the capacitance between the outer portion 172 and the VBUS terminal according to the input discharge time. For example, the discharge time when no foreign matter is present is stored in the memory as the reference time. Further, the capacitance C1 between the outer portion 172 and the VBUS terminal when no foreign matter is present is known. Therefore, it is possible to detect the capacitance corresponding to the input discharge time from the relationship between the capacitance C1 (hereinafter also referred to as “reference capacitance”) and the reference time. In this case, the comparison between the input discharge time and the reference time corresponds to the comparison between the current capacitance between the outer portion 172 and the VBUS terminal and the reference capacitance.

  Therefore, the CPU 102 compares the input discharge time with the reference time, and determines whether or not a foreign object exists between the outer portion 172 and the VBUS terminal. Specifically, when the discharge time is shorter than the reference time (that is, the detected capacitance is larger than the reference capacity), the CPU 102 determines that a foreign object is present, and the discharge time is the reference time. In the case of the above (that is, the detected electrostatic capacity is equal to or less than the reference capacity), the CPU 102 determines that no foreign matter is present.

  As another method, a configuration for detecting the capacitance between the outer portion 172 and the VBUS terminal may be used. For example, the measurement circuit 120 is configured to supply a current to the outer portion 172 to charge the capacitance between the outer portion 172 and the VBUS terminal, and to measure the capacitance based on a change in voltage accompanying charging. There may be. The measurement circuit 120 may be configured to input the detected capacitance to the CPU 102.

  Referring to FIG. 2 again, CPU 102 displays on display 110 the determination result as to whether or not a foreign object exists between outer portion 172 and the VBUS terminal. For example, if there is a foreign object, the CPU 102 displays a warning message “There is a foreign object in the connector!” On the display 110. Thereby, it is possible to notify the user of the presence of a foreign object between the outer portion 172 and the VBUS terminal of the USB connector 116.

  Further, when the CPU 102 determines that a foreign object exists, the CPU 156 maintains the OFF state of the switch 156. According to this, even if the electronic device 10 in a state where foreign matter exists between the outer portion 172 and the VBUS terminal is connected to the AC adapter 20, the overcurrent path is interrupted as shown in FIG. can do.

  FIG. 4 is a diagram showing a configuration in which AC adapter 20 is connected to electronic device 10 according to the present embodiment. Referring to FIG. 4, in electronic device 10, switch 156 is in an OFF state because the presence of a foreign object is detected by the detection method described above. Therefore, even if foreign matter adheres between the outer portion 172 and the VBUS terminal and the outer portion 172 and the VBUS terminal are short-circuited, the overcurrent path as shown in FIG. 4 can be interrupted. That is, the outer portion 172 is brought into a floating state. From this, the switch 156 not only functions as a switch used for foreign object detection, but also functions as a switch for interrupting an overcurrent due to a short circuit abnormality between the outer portion 172 and the VBUS terminal (both (It also functions as

  Even if electronic device 10 according to the present embodiment is not connected to an external power supply, it can detect the presence of a foreign substance in the connector and can notify the user of the detection result. Therefore, it is possible to prevent the user from connecting the electronic device 10 in which a foreign object exists in the connector to an external device (such as the AC adapter 20).

  Furthermore, even if the user connects the electronic device 10 in which a foreign object exists in the connector to an external device, the electronic device 10 is configured to block the overcurrent path. ing. Therefore, the electronic device 10 can prevent melting of the casing of the electronic device 10 due to overcurrent, smoke generation, and the like.

<Hardware configuration>
FIG. 5 is a block diagram showing a hardware configuration of electronic device 10 according to the present embodiment. Referring to FIG. 5, electronic device 10 includes, as main components, CPU 102, memory 104, touch panel 106, timekeeping unit 108, display 110, wireless communication unit 112, communication antenna 113, and USB connector. 116, an external interface 118, a measurement circuit 120, a speaker 122, a storage battery 124, and a charging circuit 126.

  The CPU 102 controls the operation of each unit of the electronic device 10 by reading and executing the program stored in the memory 104. More specifically, the CPU 102 implements each process (step) of the electronic device 10 to be described later by executing the program. The CPU 102 is, for example, a microprocessor.

  The memory 104 is realized by a RAM (Random Access Memory), a ROM (Read-Only Memory), a flash memory, or the like. The memory 104 stores a program executed by the CPU 102 or data used by the CPU 102.

  The touch panel 106 is provided on a display 110 having a function as a display unit, and may be any type such as a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitance method. . The touch panel 106 may include an optical sensor liquid crystal. The touch panel 106 detects a touch operation on the touch panel 106 by an external object every predetermined time, and inputs touch coordinates (touch position) to the CPU 102.

  The wireless communication unit 112 is connected to the mobile communication network via the communication antenna 113 and transmits and receives signals for wireless communication. Thereby, the electronic device 10 can communicate with a predetermined communication device via a mobile communication network such as a third generation mobile communication system (3G) or LTE (Long Term Evolution).

  The USB connector 116 connects the electronic device 10 and an external device. The USB connector 116 has a VBUS terminal (power supply terminal) for supplying power from the host, a D + / D− terminal for transmitting a differential signal, a GND terminal (ground terminal), and an ID terminal. The USB connector 116 is realized as various interfaces such as a communication interface and a memory interface.

  The external interface 118 is realized as a memory interface, for example, and reads data from an external storage medium. The CPU 102 reads data stored in an external storage medium and stores the data in the memory 104. The CPU 102 reads data from the memory 104 and stores the data in an external storage medium via the USB connector 116. Examples of the storage medium include a CD (Compact Disc), a DVD (Digital Versatile Disk), a BD (Blu-ray (registered trademark) Disc), and a USB memory. When implemented as a communication interface, the external interface 118 exchanges various data between the electronic device 10 and an external device. The communication method may be, for example, wireless communication using a wireless local area network (LAN) or wired communication.

  The measurement circuit 120 measures the discharge time and the capacitance between the outer portion 172 and the VBUS terminal, and transmits the measurement result to the CPU 102.

  The speaker 122 outputs sound based on an instruction from the CPU 102. For example, the speaker 122 outputs a warning sound when a short circuit abnormality has occurred inside the connector.

  The storage battery 124 is a chargeable / dischargeable power storage element, and typically includes a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The storage battery 124 is configured by connecting a plurality of battery cells in series, for example.

  The charging circuit 126 charges the storage battery 124 with external power received via the USB connector 116. The charging circuit 126 controls the voltage and current supplied to the storage battery 124.

<Functional configuration>
FIG. 6 is a functional block diagram of electronic device 10 according to the present embodiment. Referring to FIG. 6, electronic device 10 includes an open / close control unit 200, a detection unit 202, a determination unit 204, and a notification unit 206 as its main functional configuration. These are basically realized by the CPU 102 of the electronic device 10 executing a program stored in the memory 104 and giving a command to the components of the electronic device 10. That is, the CPU 102 has a function as a control unit that controls the entire operation of the electronic device 10. Note that some or all of these functional configurations may be realized by hardware.

  The opening / closing control unit 200 controls the opening / closing operation of the switch 156 provided between the outer portion 172 and the ground electrode.

  The detection unit 202 detects a capacitance between the outer portion 172 and the GND electrode of the substrate. Specifically, the detection unit 202 receives the discharge time from the measurement circuit 120 and detects the capacitance. Specifically, the detection unit 202 corresponds to the input discharge time from the relationship between the reference capacity (capacitance C1 when no foreign matter is present) between the outer part 172 and the VBUS terminal and the reference time. Detect the capacitance. In this case, the reference capacity and the reference time are stored in the memory 104 in advance.

  The detection unit 202 may be configured to detect the capacitance by directly receiving the capacitance measured by the measurement circuit 120. In addition, after the opening / closing control unit 200 opens the switch 156 and the outer portion 172 and the ground electrode are shut off, the detection unit 202 executes processing for detecting capacitance.

  Based on the capacitance detected by the detection unit 202, the determination unit 204 determines whether there is a foreign object between the outer portion 172 and the VBUS terminal. Specifically, the determination unit 204 determines that there is a foreign object between the outer portion 172 and the VBUS terminal when the capacitance detected by the detection unit 202 is larger than the reference capacitance. In addition, the determination unit 204 determines that the foreign matter does not exist when the electrostatic capacity is less than the reference capacity. Note that the determination unit 204 may make the determination by comparing the discharge time with the reference time. Specifically, the determination unit 204 determines that foreign matter is present when the discharge time is shorter than the reference time, and determines that no foreign matter is present when the discharge time is equal to or longer than the reference time. .

  The notification unit 206 notifies (for example, to the user) the presence of a foreign object between the outline unit 172 and the VBUS terminal based on the determination result of the determination unit 204. Specifically, when the determination unit 204 determines that a foreign object exists, the notification unit 206 notifies the user that a foreign object exists. More specifically, the notification unit 206 causes the display 110 to display a message indicating the presence of a foreign object. Or the alerting | reporting part 206 may output the audio | voice which shows presence of a foreign material from the speaker 122. FIG. Note that the notification unit 206 may notify the user that no foreign matter is present when the determination unit 204 determines that no foreign matter is present.

  When the determination unit 204 determines that no foreign matter is present, the opening / closing control unit 200 connects the outer portion 172 and the GND electrode by closing the switch 156. When the determination unit 204 determines that a foreign substance is present, the opening / closing control unit 200 opens the switch 156 to shut off the outer portion 172 and the ground electrode. In other words, the open / close control unit 200 maintains the open state of the switch 156. This is because the switch 156 is open when the detection process by the detection unit 202 and the determination process by the determination unit 204 are being performed.

<Processing procedure>
FIG. 7 is a flowchart showing a foreign object detection processing procedure executed by electronic device 10 according to the present embodiment. The following steps are basically realized by the CPU 102 of the electronic device 10 executing a program stored in the memory 104. Here, a case where the electronic device 10 determines the presence of a foreign object between the outer portion 172 and the VBUS terminal by comparing the discharge time and the reference time will be described.

  CPU 102 determines whether or not a predetermined time has elapsed since the previous detection timing (step S10). For example, when the display 110 is in an ON state (for example, a state in which the display 110 is displaying an image instead of a black screen), the predetermined time is set to 100 ms. When the display 110 is in the OFF state, the predetermined time is set to 10 s.

  The CPU 102 transmits a control signal to the switch 156 to turn off the switch 156 (step S12). Next, the measurement circuit 120 charges the capacitor 132 in accordance with an instruction from the CPU 102 (step S14). Then, when the charging of the capacitor 132 is completed, the measuring circuit 120 discharges from the capacitor 132 to the outer portion 172 side (step S16).

  The CPU 102 receives the discharge time from the measurement circuit 120 and determines whether or not the discharge time is longer than the reference time (step S18). If the discharge time is longer than the reference time (YES in step S18), CPU 102 turns on switch 156 (step S20) and repeats the processing from step S10.

  On the other hand, when the discharge time is equal to or shorter than the reference time (NO in step S18), the CPU 102 notifies that there is a foreign object between the outer portion 172 and the VBUS terminal (step S22). For example, the CPU 102 displays a message indicating that on the display 110. And CPU102 repeats the process from step S10. In this case, the CPU 102 maintains the switch 156 in the OFF state.

<Other embodiments>
It is also possible to provide a program that causes a computer to function and execute control as described in the above flowchart. Such a program is recorded on a non-temporary computer-readable recording medium such as a flexible disk attached to the computer, a CD-ROM (Compact Disk Read Only Memory), a ROM, a RAM, and a memory card as a program product. It can also be provided. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.

  The program may be a program module that is provided as a part of an operating system (OS) of a computer and that calls necessary modules in a predetermined arrangement at a predetermined timing to execute processing. In that case, the program itself does not include the module, and the process is executed in cooperation with the OS. A program that does not include such a module can also be included in the program according to the present embodiment.

  Further, the program according to the present embodiment may be provided by being incorporated in a part of another program. Even in this case, the program itself does not include the module included in the other program, and the process is executed in cooperation with the other program. A program incorporated in such another program can also be included in the program according to the present embodiment.

<Effect of Embodiment>
According to the present embodiment, even if the electronic device is not connected to an external power source, the presence of foreign matter (such as water wetting) in the connector can be detected. Further, this can be notified to the user. Therefore, it is possible to prevent in advance heat generation due to overcurrent that may occur when an external power source is connected when foreign matter is present in the connector.

  According to the present embodiment, the electronic device is configured to block the overcurrent path even when the electronic device in the state where the foreign substance exists in the connector is connected to the external device. . Therefore, even if the user accidentally connects the electronic device to an external device without noticing that there is a foreign object in the connector, the housing of the electronic device melts due to overcurrent, Smoke does not occur.

  According to the present embodiment, since the switch used for foreign object detection is also used as a switch for interrupting the overcurrent path, it is not necessary to prepare another switch.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10,1000 electronic device, 20 AC adapter, 22 power supply, 24 adapter cable, 102 CPU, 104 memory, 106 touch panel, 108 timing unit, 110 display, 112 wireless communication unit, 113 communication antenna, 116, 1300 connector, 118 external interface , 120 measurement circuit, 122 speaker, 124 storage battery, 126, 1200 charging circuit, 132 capacitor, 156 switch, 172, 1400 outer part, 200 opening / closing control part, 202 detection part, 204 judgment part.

Claims (5)

Electronic equipment,
It has a connector for connecting to an external device,
The connector includes a power supply terminal, a ground terminal, and a conductive outer portion that forms an outer shell of the connector,
A detection unit for detecting a capacitance between the outer portion and the ground electrode;
Based on the detected capacitance, a determination unit that determines whether there is a foreign object between the outer portion and the power supply terminal;
An electronic device further comprising: a notification unit that notifies the presence of the foreign object based on a determination result of the determination unit. A switch provided between the outer portion and the ground electrode;
An opening / closing control unit for controlling the switch;
The said detection part performs the process which detects the said electrostatic capacitance, after the said outer part and the said ground electrode are interrupted | blocked by the said switching control part opening the said switch. Electronics. The opening / closing controller is
When the determination unit determines that no foreign matter exists between the outer portion and the power supply terminal, the outer portion and the ground electrode are connected by closing the switch,
3. The electronic device according to claim 2, wherein when the determination unit determines that a foreign object is present between the outer portion and the power supply terminal, the electronic switch according to claim 2 maintains the open state of the switch.   The electronic device according to claim 2, wherein the switch also serves as a switch for interrupting an overcurrent due to a short circuit abnormality between the outer portion and the power supply terminal. When the capacitance detected by the detection unit is larger than a reference capacitance, the determination unit determines that there is a foreign object between the outer portion and the power supply terminal,
The electronic device according to claim 1, wherein the notification unit notifies that the foreign matter is present.

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