WO2013118429A1

WO2013118429A1 - Electronic equipment

Info

Publication number: WO2013118429A1
Application number: PCT/JP2013/000206
Authority: WO
Inventors: 藤森　一彦
Original assignee: パナソニック株式会社
Priority date: 2012-02-10
Filing date: 2013-01-17
Publication date: 2013-08-15
Also published as: JPWO2013118429A1

Abstract

There are included: a receiver/speaker combination device (2) in which a receiver used during a normal telephone communication is integrated with a speaker used during a hands-free telephone communication; an amplification unit (3) that supplies an amplified sound signal to the receiver/speaker combination device (2); a first power supply unit (4) that supplies, to the amplification unit (3), a power used during the hands-free telephone communication; a second power supply unit (5) that supplies, to the amplification unit (3), a power used during the normal telephone communication and that has a lower supply capacity than the first power supply unit (4); and a power supply switch unit (6) that connects the first power supply unit (4) to the amplification unit (3) during the hands-free telephone communication and that connects the second power supply unit (5) to the amplification unit (3) during the normal telephone communication. During an abnormal state in which the power supply switch unit (6) is not controlled, the second power supply unit (5) is connected to the amplification unit (3).

Description

Electronics

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a call function such as a mobile phone, and more particularly to an electronic device including a receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated.

As a technique related to the present invention, there is a mobile phone described in Patent Document 1. In the cellular phone described in Patent Document 1, infrared light emitting elements and infrared light receiving elements are arranged at predetermined intervals in the horizontal direction or vertical direction of the display window to detect the approach or contact of the face or ear to the telephone body. In this way, the hands-free call is switched to the normal call so that no loud sound is output during the normal call. By preventing the loud sound from being output during a normal call using the telephone body while touching the face, the user's hearing is not impaired.

Japanese Laid-Open Patent Publication No. 10-028169

However, although the mobile phone described in Patent Document 1 switches the volume by detecting the approach or contact of the human body, this is a normal measure, and if the volume cannot be switched during an abnormality, There is a risk of generating volume. If a large volume is generated in a normal call state, the user's hearing may be disturbed.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic device that does not generate a large volume even when the volume cannot be switched during an abnormality.

An electronic apparatus according to the present invention includes a receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated, and an amplifying unit that supplies an amplified audio signal to the receiver / speaker combined device A first power supply unit that supplies power used during a hands-free call to the amplifying unit, and a second power supply unit that supplies power used during normal calling to the amplifying unit and has a lower supply capability than the first power supply unit. A power supply switching unit that connects the first power supply unit to the amplifying unit during a hands-free call and connects the second power supply unit to the amplifying unit during a normal call. In an abnormal state in which the unit is not controlled, the second power supply unit is connected to the amplifying unit.

According to the above configuration, in an abnormal state in which the power supply switching unit is not controlled, the second power supply unit having a lower supply capacity than the first power supply unit is connected to the amplification unit, so that a large volume does not occur. The user's hearing is not impaired.

An electronic apparatus according to the present invention includes a receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated, and an amplifying unit that supplies an amplified audio signal to the receiver / speaker combined device A power supply unit that supplies power to the amplification unit, a current limiting unit that limits a current flowing through the amplification unit during a normal call to a current value smaller than a current flowing through the amplification unit during a hands-free call, and a hands-free call A current limit switching unit that sometimes grounds the ground of the amplification unit and grounds the ground of the amplification unit via the current limiting unit during a normal call, and in an abnormal state in which the current limit switching unit is not controlled, The ground of the amplifying unit is grounded through the current limiting unit.

According to the above configuration, in an abnormal state where the current limit switching unit is not controlled, since the ground of the amplifying unit is grounded via the current limiting unit, no loud sound is generated and the user's hearing is impaired. There is no end.

An electronic apparatus according to the present invention includes a receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated, and an amplifying unit that supplies an amplified audio signal to the receiver / speaker combined device An amplitude level detection unit that detects that the amplitude level of the amplified audio signal supplied from the amplification unit to the receiver / speaker combined device exceeds a predetermined value, and the amplitude level detection unit during a normal call And an audio signal blocking unit that blocks an amplified audio signal supplied from the amplification unit to the receiver / speaker combined device in accordance with the detected output.

According to the above configuration, during a normal call, amplification is performed according to the detection output of the amplitude level detection unit that detects that the amplitude level of the amplified audio signal supplied to the receiver / speaker combined device exceeds a predetermined value. Since the amplified audio signal supplied from the unit to the receiver / speaker combined device is cut off, no loud sound is generated and the user's hearing is not impaired.

According to the present invention, even if a device that controls the volume of the CPU or the like during a normal call breaks down and switching between a normal call and a hands-free call cannot be performed, a high volume is not generated during the normal call. It will not damage your hearing.

1 is a block diagram showing a schematic configuration of an electronic device according to Embodiment 1 of the present invention. The flowchart for demonstrating operation | movement of the electronic device of FIG. The block diagram which shows schematic structure of the electronic device which concerns on Embodiment 2 of this invention. The flowchart for demonstrating operation | movement of the electronic device of FIG. The block diagram which shows schematic structure of the electronic device which concerns on Embodiment 3 of this invention. Flowchart for explaining the operation of the electronic device of FIG.

Hereinafter, preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a schematic configuration of an electronic apparatus according to Embodiment 1 of the present invention. The electronic device 1 according to the present embodiment is a portable wireless device having a receiver / speaker combined device 2 in which a receiver used during a normal call and a speaker used during a hands-free call are integrated.

In FIG. 1, an electronic apparatus 1 according to the present embodiment includes an amplifying unit 3, a first power source unit 4, a second power source unit 5, and a power source switching in addition to the receiver / speaker combined device 2 described above. Unit 6 and CPU 7 are provided. The amplifying unit 3 amplifies an audio signal output from a CPU (Central Processing Unit) 7 and supplies the amplified audio signal to the receiver / speaker combined device 2. The first power supply unit 4 supplies power used during a hands-free call to the amplification unit 3, and activation / deactivation (that is, on / off) is controlled by the CPU 7. The supply capacity of the first power supply unit 4 is, for example, 1A. The second power supply unit 5 supplies power used during normal telephone calls to the amplification unit 3, and activation / deactivation (that is, on / off) is controlled by the CPU 7. The 2nd power supply part 5 is a power supply whose supply capability is lower than the 1st power supply part 4, The supply capability is less than 100 mA, for example.

The power supply switching unit 6 is a changeover switch having two fixed contacts a and b and one movable contact c. The fixed contact a is connected to a power output terminal (not shown) of the second power supply unit 5 and fixed. The contact b is connected to the power output terminal (not shown) of the first power supply unit 4, and the movable contact c is connected to the power input terminal (not shown) of the amplification unit 3. The movable contact c of the power supply switching unit 6 is connected to the fixed contact a in a default state, and is switched to the fixed contact b side when a switching signal is received from the CPU 7. When the movable contact c is switched to the fixed contact b side, the first power supply unit 4 and the amplification unit 3 are connected.

The CPU 7 controls the start / stop (on / off) of the first and second power supply units 4, 5, the switching control of the power supply switching unit 6, and the start / stop (on / off) control of the amplification unit 3. Do. In this case, the CPU 7 outputs a switching signal to the power supply switching unit 6 and outputs a control signal including an audio signal (a control signal for controlling on / off of the amplification unit 3) to the amplification unit 3. During a hands-free call using the receiver / speaker combined device 2 as a speaker, the CPU 7 switches the movable contact c of the power supply switching unit 6 to the fixed contact b side, and connects the first power supply unit 4 to the amplification unit 3. That is, when the receiver / speaker combined device 2 is used as a speaker, the volume is sufficient, so the first power supply unit 4 capable of flowing a large current is selected. On the other hand, during a normal call using the receiver / speaker combined device 2 as a receiver, the movable contact c of the power supply switching unit 6 is switched to the fixed contact a side, and the second power supply unit 5 is connected to the amplification unit 3. . That is, when the receiver / speaker combined device 2 is used as a receiver, a high sound volume is not required, so the second power supply unit 5 that supplies a small current is selected.

As described above, since the movable contact c of the power switching unit 6 is connected to the fixed contact a in the default state, the movable contact c of the power switching unit 6 is connected to the fixed contact a except during a hands-free call. ing. Therefore, in practice, the movable contact c is switched to the fixed contact a side only by canceling the control during the hands-free call instead of performing the control for switching the movable contact c to the fixed contact a side during a normal call. Become. In this way, by connecting the movable contact c of the power supply switching unit 6 to the fixed contact a in the default state, even if the CPU 7 does not operate due to static electricity or external factors, the movable contact c of the power supply switching unit 6 is fixed to the fixed contact b. Since the first power supply unit 4 is not connected to the amplifier 3 (ie, the first power supply unit 4 is not connected to the amplifying unit 3), no loud sound is generated. As a result, the user's hearing is not impaired.

Next, the operation of electronic device 1 according to the present embodiment will be described.
FIG. 2 is a flowchart for explaining the operation of electronic device 1 according to the present embodiment. In the figure, the CPU 7 generates a notification event (step S1), and subsequently performs voice path initial setting (step S2). In the audio path initial setting, the CPU 7 performs settings for making sound to the amplification unit 3. After initial setting of the voice path, the CPU 7 determines whether the voice output path is a speaker (step S3). That is, it is determined whether or not the hands-free setting is set. If it is determined that the audio output path is a speaker (ie, if “Yes” is determined in step S3), the power supply switching unit 6 is set to the speaker side (step S4). That is, the CPU 7 outputs a switching signal for switching the movable contact c of the power supply switching unit 6 to the fixed contact b side. Thereby, the movable contact c of the power supply switching unit 6 is switched to the fixed contact b side, and the first power supply unit 4 is connected to the amplification unit 3. After connecting the first power supply unit 4 to the amplification unit 3, the CPU 7 outputs a control signal including an audio signal to the amplification unit 3 to start ringing (step S5).

On the other hand, if it is determined in step S3 that the audio output path is not a speaker (ie, if “No” is determined in step S3), the power supply switching unit 6 is set on the receiver side (step S6). ). In this case, if a switching signal is output to the power supply switching unit 6 at the present time, the output of the switching signal is stopped. On the other hand, if no switching signal is output to the power supply switching unit 6 at this time, no processing related to switching is performed. That is, the movable contact c of the power supply switching unit 6 is left in the default state. When the output of the switching signal to the power supply switching unit 6 is stopped, the movable contact c of the power supply switching unit 6 is switched to the fixed contact a side, and the second power supply unit 5 is connected to the amplification unit 3. After connecting the second power supply unit 5 to the amplification unit 3, the CPU 7 outputs a control signal including an audio signal to the amplification unit 3 to start ringing (step S5). In this case, since the receiver / speaker combined device 2 is used as a receiver, it rings at a low volume.

As described above, according to the electronic device 1 according to the present embodiment, in the abnormal state where the power supply switching unit 6 is not controlled by the CPU 7, the second power supply unit 5 having a lower supply capability than the first power supply unit 4 is used as the amplification unit 3. Therefore, no loud sound is generated and the user's hearing is not impaired.

(Embodiment 2)
FIG. 3 is a block diagram showing a schematic configuration of the electronic apparatus according to Embodiment 2 of the present invention. Electronic device 10 according to the present exemplary embodiment is a receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated, similarly to electronic device 1 according to the first exemplary embodiment described above. 2 is a portable wireless device.

In FIG. 3, an electronic device 10 according to the present embodiment includes a power supply unit 11 having the same supply capability (for example, 1A) as the first power supply unit 4 of the electronic device 1 according to the first embodiment described above, A current limit switching unit 12, a current limit unit (so-called current limiter) 13, and a ground line 14 are included. The power supply unit 11 supplies a constant current to the amplifying unit 3 regardless of a hands-free call or a normal call. The CPU 7 controls start / stop (that is, on / off) of the power supply unit 11. The current limit switching unit 12 is a changeover switch having two fixed contacts a and b and one movable contact c. The fixed contact a is grounded via the current limit unit 13 and the fixed contact b is connected to the ground line 14. The movable contact c is connected to the ground (not shown) of the amplifying unit 3. The movable contact c of the current limit switching unit 12 is connected to the fixed contact a in a default state, and is switched to the fixed contact b side when a switching signal is received from the CPU 7. When the movable contact c is switched to the fixed contact a side, the ground of the amplifying unit 3 is grounded via the current limiting unit 13. Further, the movable contact c is switched to the fixed contact b side, whereby the ground of the amplifying unit 3 is grounded by the ground wire 14. The current limiting unit 13 limits the current flowing through the amplifying unit 3 to a small current value.

The CPU 7 performs start / stop (on / off) control of the power supply unit 11, start / stop (on / off) control of the amplification unit 3, and switching control of the current limit switching unit 12. In this case, the CPU 7 outputs a control signal including an audio signal to the amplifying unit 3 (a control signal for controlling on / off of the amplifying unit 3), and outputs a switching signal to the current limit switching unit 12. During a hands-free call using the receiver / speaker combined device 2 as a speaker, the CPU 7 switches the movable contact c of the current limit switching unit 12 to the fixed contact b side, and connects the ground end of the amplification unit 3 via the ground line 14. Ground. That is, when the receiver / speaker combined device 2 is used as a speaker, the volume may be high, so that there is no need to limit the current to the amplifying unit 3, and the ground of the amplifying unit 3 is grounded as it is.

In contrast, during a normal call using the receiver / speaker combined device 2 as a receiver, the movable contact c of the current limit switching unit 12 is switched to the fixed contact a side, and the ground of the amplification unit 3 is connected via the current limit unit 13. Ground. That is, when the receiver / speaker combined device 2 is used as a receiver, a large volume is not required, so that it is necessary to limit the current to the amplifying unit 3, and the ground terminal of the amplifying unit 3 is connected via the current limiting unit 13 Ground. By interposing the current limiting unit 13 between the ground and the ground of the amplifying unit 3, the current flowing through the amplifying unit 3 during a normal call is limited to a current value smaller than the current flowing through the amplifying unit 3 during a hands-free call.

As described above, since the movable contact c of the current limit switching unit 12 is connected to the fixed contact a in the default state, the movable contact c of the current limit switching unit 12 is fixed to the fixed contact a except during a hands-free call. It is connected. Therefore, in practice, the movable contact c is switched to the fixed contact a side only by canceling the control during the hands-free call instead of performing the control for switching the movable contact c to the fixed contact a side during a normal call. Become. As described above, when the movable contact c of the current limit switching unit 12 is connected to the fixed contact a in the default state, the movable contact c of the current limit switching unit 12 can be operated even if the CPU 7 does not operate due to static electricity or an external factor. Since there is no switching to the fixed contact b side (that is, the ground end of the amplifying unit 3 is not grounded), no loud sound is generated at the time of abnormality. As a result, the user's hearing is not impaired.

Next, the operation of electronic device 10 according to the present embodiment will be described.
FIG. 4 is a flowchart for explaining the operation of electronic device 10 according to the present embodiment. In the figure, the CPU 7 generates a notification event (step S10), and subsequently performs voice path initial setting (step S11). In the audio path initial setting, the CPU 7 performs settings for making sound to the amplification unit 3. After the audio path initial setting, it is determined whether the audio output path is a speaker (step S12). That is, it is determined whether or not the hands-free setting is set. If it is determined that the audio output path is a speaker (ie, if “Yes” is determined in step S12), the current limit switching unit 12 is set to the speaker side (step S13). That is, a switching signal for switching the movable contact c of the current limit switching unit 12 to the fixed contact b side is output. Thereby, the movable contact c of the current limit switching unit 12 is switched to the fixed contact b side, and the ground of the amplification unit 3 is grounded via the ground line 14. After grounding the ground of the amplifying unit 3, the CPU 7 outputs a control signal including an audio signal to the amplifying unit 3 to start ringing (step S14).

On the other hand, if it is determined in step S12 that the audio output path is not a speaker (that is, if “No” is determined in step S12), the current limit switching unit 12 is set on the receiver side (step S12). S15). In this case, if a switching signal is output to the current limit switching unit 12 at this time, the output of the switching signal is stopped. On the other hand, if no switching signal is output to the current limit switching unit 12 at this time, no processing related to switching is performed. That is, the movable contact c of the current limit switching unit 12 is left in the default state. When the output of the switching signal to the current limit switching unit 12 is stopped, the movable contact c of the current limit switching unit 12 is switched to the fixed contact a side, and the ground of the amplifying unit 3 is grounded via the current limiting unit 13. The The CPU 7 grounds the amplification unit 3 via the current limiting unit 13, and then outputs a control signal including an audio signal to the amplification unit 3 to start ringing (step S14). In this case, since the receiver / speaker combined device 2 is used as a receiver, it rings at a low volume.

As described above, according to the electronic device 10 according to the present embodiment, in an abnormal state where the current limit switching unit 12 is not controlled by the CPU 7, the ground of the amplification unit 3 is grounded via the current limit unit 13. No sound volume is generated and the user's hearing is not impaired.

(Embodiment 3)
FIG. 5 is a block diagram showing a schematic configuration of an electronic apparatus according to Embodiment 3 of the present invention. Electronic device 20 according to the present embodiment is a receiver / speaker combined device in which a receiver that is used during a normal call and a speaker that is used during a hands-free call are integrated, similarly to electronic device 1 according to the first embodiment described above. 2 is a portable wireless device.

In FIG. 5, the electronic device 20 according to the present embodiment includes a power supply unit 21 having the same supply capability (for example, 1A) as the first power supply unit 4 of the electronic device 1 according to the first embodiment described above, An amplitude level detection unit 22 for detecting that the amplitude level of the amplified audio signal supplied from the amplification unit 3 to the receiver / speaker combined device 2 exceeds a predetermined value; According to the detection output, an audio signal blocking unit 23 that blocks the amplified audio signal supplied from the amplification unit 3 to the receiver / speaker combined device 2 is provided. The power supply unit 21 supplies a constant current to the amplifying unit 3 regardless of a hands-free call or a normal call. The CPU 7 controls start / stop (that is, on / off) of the power supply unit 21.

The audio signal cut-off unit 23 has an open / close switch having one fixed contact a and one movable contact c, and the fixed contact a is connected to one of the two input ends of the receiver / speaker combined device 2 to be movable. The contact c is connected to the signal side output terminal of the amplitude level detector 22. The other of the two input terminals of the receiver / speaker combined device 2 is connected to the ground side output terminal of the amplitude level detector 22.

The CPU 7 performs start / stop (on / off) control of the power supply unit 21, start / stop (on / off) control of the amplification unit 3, and setting of the amplitude level detection unit 22. In this case, the CPU 7 outputs to the amplifying unit 3 a control signal including an audio signal (a control signal for controlling on / off of the amplifying unit 3). Further, the CPU 7 sets a predetermined value in the amplitude level detection unit 22 that exceeds the amplitude level of the audio signal output from the amplification unit 3 during a normal call. This set value is a value lower than the amplitude level of the audio signal output from the amplifying unit 3 during a hands-free call. In addition, the CPU 7 outputs a signal that informs the amplitude level detection unit 22 whether it is a normal call or a hands-free call.

When the amplitude level detection unit 22 receives a notification from the CPU 7 that it is during a normal call, the amplitude level detection unit 22 monitors the amplitude level of the amplified audio signal supplied from the amplification unit 3 to the receiver / speaker combined device 2. It is detected that the amplitude level exceeds a predetermined value. In addition, when the amplitude level detection unit 22 receives a notification from the CPU 7 that the hands-free call is in progress, the amplitude level of the amplified audio signal supplied from the amplification unit 3 to the receiver / speaker combined device 2 is displayed. There is no monitoring. That is, the detection of the amplitude level of the audio signal amplified by the amplifying unit 3 is not performed.

The audio signal blocking unit 23 blocks the amplified audio signal supplied from the amplification unit 3 to the receiver / speaker combined device 2 according to the detection output of the amplitude level detection unit 22. As described above, when the amplitude level of the amplified audio signal supplied from the amplifying unit 3 to the receiver / speaker combined device 2 exceeds a predetermined value during a normal call, the audio signal is blocked and the receiver / speaker is There is no supply to the dual-purpose device 2. That is, when an abnormality occurs during a normal call and an audio signal having an amplitude level exceeding the amplitude level during a normal call is output from the amplification unit 3, the audio signal is cut off, and the audio is received from the receiver / speaker combined device 2. Prevent output. In this way, even if the CPU 7 does not operate due to static electricity or external factors, and an audio signal having a large amplitude level is output from the amplification unit 3, a large volume is output from the receiver / speaker device 2. And there will be no disturbance to the user's hearing.

Next, the operation of the electronic device 20 according to the present embodiment will be described.
FIG. 6 is a flowchart for explaining the operation of electronic device 20 according to the present embodiment. In the figure, the CPU 7 generates a notification event (step S20), and then performs voice path initial setting (step S21). In the audio path initial setting, the CPU 7 performs settings for making sound to the amplification unit 3. After the audio path is initially set by the CPU 7, the amplitude level detector 22 monitors the amplitude level of the audio signal amplified by the amplifier 3, and detects that the predetermined value has been exceeded (step S22). The amplitude level detection unit 22 determines whether or not the current audio output path is a receiver setting (step S23). If the audio output path is a receiver setting (ie, the amplitude level detection unit 22 determines “Yes” in the determination in step S23). When it is determined, the audio signal blocking unit 23 blocks the audio signal amplified by the amplification unit 3 in accordance with the detection output of the amplitude level detection unit 22 (step S24).

On the other hand, when the amplitude level detection unit 22 determines that the current audio output path is not a receiver setting in the determination in step S23 (that is, if the determination in step S23 determines “No”), the audio signal blocking unit. 23 does not block the audio signal amplified by the amplifying unit 3 and continues ringing (step S25).

As described above, according to the electronic apparatus 20 according to the present embodiment, during a normal call, the amplitude for detecting that the amplitude level of the amplified audio signal supplied to the receiver / speaker combined device 2 exceeds a predetermined value. According to the detection output of the level detection unit 22, the amplified audio signal supplied from the amplification unit 3 to the receiver / speaker combined device 2 is blocked, so that a large volume is output from the receiver / speaker combined device 2. And there will be no disturbance to the user's hearing.

The program describing the functions of the

electronic devices

1, 10, and 20 according to the above embodiments may be stored and distributed in a storage medium such as a magnetic disk, hard disk, optical disk, magneto-optical disk, or semiconductor memory. it can.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

This application is based on a Japanese patent application filed on Feb. 10, 2012 (Japanese Patent Application No. 2012-027576), the contents of which are incorporated herein by reference.

The present invention has an effect that even if the volume cannot be switched at the time of abnormality, a large volume is not generated, and can be applied to a portable wireless device such as a mobile phone or a smartphone.

1, 10, 20 Electronic device 2 Receiver / speaker combined device 3 Amplifying unit 4 First power source unit 5 Second power source unit 6 Power source switching unit 7 CPU
11, 21 Power supply unit 12 Current limit switching unit 13 Current limit unit 14 Ground line 22 Amplitude level detection unit 23 Audio signal cut-off unit

Claims

A receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated;
An amplifier for supplying the amplified audio signal to the receiver / speaker combined device;
A first power supply for supplying power used during a hands-free call to the amplifier;
A second power supply unit that supplies power used during a normal call to the amplification unit and has a lower supply capacity than the first power supply unit;
A power switching unit that connects the first power supply unit to the amplification unit during a hands-free call and connects the second power supply unit to the amplification unit during a normal call;
In an abnormal state where the power supply switching unit is not controlled, the second power supply unit is connected to the amplifying unit.
A receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated;
An amplifier for supplying the amplified audio signal to the receiver / speaker combined device;
A power supply for supplying power to the amplifier;
A current limiting unit that limits a current flowing through the amplification unit during a normal call to a current value smaller than a current flowing through the amplification unit during a hands-free call;
A current limit switching unit for grounding the amplifying unit during a hands-free call, and for grounding the amplifying unit via the current limiting unit during a normal call,
In an abnormal state where the current limit switching unit is not controlled, the ground of the amplification unit is grounded via the current limit unit.
A receiver / speaker combined device in which a receiver used during a normal call and a speaker used during a hands-free call are integrated;
An amplifier for supplying the amplified audio signal to the receiver / speaker combined device;
An amplitude level detection unit for detecting that the amplitude level of the amplified audio signal supplied from the amplification unit to the receiver / speaker combined device exceeds a predetermined value;
During a normal call, an audio signal blocking unit that blocks an amplified audio signal supplied from the amplification unit to the receiver / speaker combined device according to a detection output of the amplitude level detection unit;
An electronic device characterized by comprising: