JP2000349892A - Hand-free device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hand-free device useful for using a mobile telephone when a user drives an automobile or in other similar state. SOLUTION: The hand-free device has a 3-pole or 4-pole plug 3a that is connected to a data input output terminal 2a that electrically connects a master terminal 1a of a mobile phone 1 and the hand-free device 2 or connected to an earphone microphone voice signal input output terminal 1b of the mobile phone 1, a microphone 2d, a loudspeaker 2c, and an earphone microphone voice signal output input terminal 2e. The loudspeaker 2c of the hand-free device 2 sounds a voice of a speech opposite party and in the case that a user does not desire its own speech from being heard by 3rd parties other than the user, the earphone microphone 3 is inserted to eliminate this problem. Even when the earphone microphone voice signal input output terminal 1b is used for electric connection between the hand-free device and the mobile phone, the speech state of the mobile phone is recognized similarly to the case with using a master terminal so as to realize power saving. Moreover, in the case of using the 4-pole plug, the operations such as call reception is available without the need for the button operation of user itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention discloses a hands-free device which is effective when using a mobile telephone when driving a car.

[0002]

2. Description of the Related Art When using a mobile telephone while driving a car or during a cooking situation, such as during cooking, hands-free equipment can be used to make a call with both hands free. . However, in this case, since the voice of the other party is generated from the speaker of the hands-free device, there is a possibility that a third party other than the user may hear the call. In addition, when a hands-free device is connected while waiting for an incoming call, extra power is consumed because the device always operates.

[0003]

The hands-free device (FIGS. 1 and 4) of the present invention comprises a data input / output terminal 2a, a microphone 2d, and a speaker for electrically connecting the master terminal 1a of the mobile telephone 1 to the hands-free device 2. 2
c and an earphone / microphone audio signal input / output terminal 2e. The data input / output terminal 2a is a transmission voice signal output terminal 2b
1 and received voice signal input terminal 2b 2 is an earphone microphone audio signal input / output terminal 2e is a microphone audio signal input terminal 2
e 1 and earphone audio signal output terminal 2e 2 is provided. When the earphone / microphone plug 3a of the earphone / microphone 3 is not inserted into the general hands-free device, the voice of the user input from the microphone 2d is transmitted to the transmission circuit 2f. 1, a transmission voice signal output terminal 2a 1 is transmitted from the mobile telephone 1 to the other party, and the voice of the other party is received from the mobile telephone 1 by a receiving voice signal input terminal 2a. 2 and the transmission circuit 2f 2 through the speaker 2c. When the earphone / microphone plug 3a is inserted into the hand-held device, the user's voice input through the microphone 3b of the earphone / microphone 3 is input to the microphone voice input terminal 2e. 1 and transmission circuit 2f 3, a transmission voice signal output terminal 2a 1 is transmitted from the mobile telephone 1 to the other party, and the voice of the other party is received from the mobile telephone 1 by a receiving voice signal input terminal 2a. 2 and the transmission circuit 2f
4 through the earphone audio output terminal 2e 2 and a transmission switching circuit 2g for generating sound from the earphone 3c in the general earphone microphone 1 and 2g Switch at 2.

[0004] For this reason, for example, when a person is in the front passenger seat while driving a car and it is difficult to hear the voice of the other party in the front passenger seat, the earphone microphone is inserted into the hands-free device and is attached. You can talk hands-free without being heard by others.

By setting the transmission switching circuit as shown in FIG. 3, the transmission circuit 2f shown in FIG. 1 and 2f 3
And 2f 2 and 2f 4 can be shared.

Also, by changing the setting of the amplification factor of the signal in each transmission circuit for each transmission circuit, it is difficult for the other party to hear the voice of the user except for the voice of the user when using the earphone microphone. Sometimes it's possible to set up people around you to join the call.

As a method for the hands-free device 2 to recognize that the earphone microphone plug 3a of the earphone microphone 3 is inserted hands-free, a microphone sound signal input terminal 2e of the hands-free device 2 The presence / absence of the earphone microphone is recognized by taking different values of the voltage at 1 when the earphone microphone plug 3a is inserted into the hands-free device and when it is not.

[0008] microphone in the earphone microphone to operate normally condenser microphone is used, it is necessary to bias _the power supply voltage V _cc and a pull-up resistor R _p. The earphone microphone audio signal input / output terminal 2e is a microphone audio signal input terminal 2e. 1 and earphone audio signal output terminal 2e 2, ground terminal 2e 3 and the microphone audio signal input terminal 2e when the earphone microphone plug 3a is not inserted. 1 and ground terminal 2e 3 is open. Therefore, the potential at point A becomes substantially equal to _Vcc when the input impedance of the transmission circuit is sufficiently increased.
When the earphone microphone is inserted, the potential at the point A has a value obtained by dividing the bias power supply voltage _Vcc by the impedance of the pull-up resistor _Rp and the condenser microphone itself. For this reason, the presence or absence of the earphone microphone can be determined by providing a threshold voltage at the intermediate value of the potential at the point A before and after the earphone microphone plug 3a is inserted and determining the threshold voltage by the comparator.

When the hands-free device 2 and the mobile telephone 1 are connected by the master terminal, the state of the mobile telephone 1 such as whether or not a call is being made or a button is pressed is communicated between the devices using the serial communication terminal in the master terminal. This allows hands-free devices to be recognized. However, when the earphone microphone audio signal input / output terminal 1b is used for connection between the mobile telephone 1 and the hands-free device 2, the state of the mobile telephone 1 cannot usually be grasped. When the power of the hands-free device 2 is turned on, the device must be constantly operating unless a user performs an operation, thereby consuming power.

[0010] Use at least hands-free equipment
The information required when calling is whether the mobile phone is busy
Or if the user wants to press the button to talk
Judgment is enough. Modern mobile devices save power
Designed for mobile phones
Microphone audio signal input terminal 1b during a call 1 to 1
In most cases, ias voltage is applied. Hands
Earphone My for connection between mobile device 2 and mobile phone 1
When the audio signal input / output terminal 1b is used,
Transmission audio signal output terminal 2b in earphone plug 2b
When a bias voltage over a certain value is applied to 1
It is determined that the mobile phone is in use. This algorithm
Output the transmitted voice signal when the phone is idle
Terminal 2b Only the minimum circuit that monitors the voltage of 1 operates
Call status from incoming or outgoing on mobile phone
When the main unit circuit such as a speaker amplifier is
This saves extra power consumption.

Normally, the earphone microphone audio signal input / output terminal 1b of the mobile telephone 1 is the microphone audio signal input terminal 1b. 1, speaker audio signal output terminal 1b 2, ground terminal 1b 3 is a three-pole terminal. However, depending on the manufacturer of the mobile telephone, there is also a mobile telephone having a four-pole terminal 4a in addition to operation terminals for incoming and outgoing calls. In this case, a normal operation is performed by a switch 4b provided on the earphone microphone 4 shown in FIG. By using the above-mentioned algorithm with the hands-free device using the four-pole plug 4a, the operation of terminating the call and terminating the call can be performed automatically without the need for the person to operate the switch 4b.

[00012]

[Application example] Fig. 7 shows an example of using the present hands-free device in a headset used in a motorcycle or the like. FIG. 6 shows a microphone sound signal output terminal 2b when a call is received and a call is terminated from a state where the mobile phone is in a standby state and the call is terminated. 1 shows a change in voltage at point B in FIG. The hands-free device 5 has a headset 5d effective for driving a motorcycle and the like. 5a is a headphone speaker, and 5b is a flexible microphone. The handsley device is connected to the mobile phone with a four-pole plug 5c and monitors the voltage at point B. If the voltage is lower than a predetermined certain value, the telephone determines that the telephone is on standby and continues monitoring. When a voltage exceeding a certain value appears, it is determined that there is an incoming call to the mobile phone, the main circuit such as an amplifier is activated, and the operation terminal is operated by the transistor circuit or the like of the hands-free device 2 so that the mobile telephone 1 is operated. Make a call. During the telephone call, the monitoring of the voltage at the point B is continued, and when the voltage falls below a certain value, the telephone is returned to a standby state by operating the operation terminal q to stop the operation of the main circuit. In this case, there is no need to press the button on the mobile phone,
This is very effective when both hands are completely blocked, such as when driving, and there is a danger in operation.

[Brief description of the drawings]

FIG. 1 shows a configuration 1 according to the present invention. (Use master terminal to connect to mobile phone)

FIG. 2 is a configuration 2 according to the invention. (Use the earphone / microphone audio signal input / output terminal to connect to a mobile phone)

FIG. 3 is a circuit configuration 1 of a hands-free device.

FIG. 4 is a circuit diagram 2 of a hands-free device.

FIG. 5 is an earphone microphone with a 4-pole plug.

FIG. 6 is a change graph of a point B voltage.

FIG. 7 shows an example of use of the present invention.

[Explanation of symbols]

Reference Signs List 1 mobile device 1a master terminal (data input / output terminal) 1b earphone microphone audio signal input / output terminal 2 hands-free device 2a data input / output terminal 2a 1 Transmission voice signal output terminal 2a 2 Reception voice signal input terminal 2b Earphone microphone plug 2c Speaker 2d Microphone 2e Earphone microphone voice signal input / output terminal 2e 1 microphone audio signal input terminal 2e 2 Speaker audio signal output terminal 3 Earphone microphone (3 poles) 4 Earphone microphone (4 poles) 5 Headset

Claims (4)

[Claims] 1. A hands-free device having a data input / output terminal 2a, a microphone 2d, a speaker 2c, and an earphone / microphone audio signal input / output terminal 2e for electrically connecting a master terminal 1a of a mobile phone 1 to a hands-free device 2. 1 and FIG. 4), when the earphone / microphone plug 3a of the earphone / microphone 3 is not inserted into the almost hands-free device, the user's voice input from the microphone 2d is transmitted to the transmission circuit 2f. 1, a transmission voice signal output terminal 2a 1 is transmitted from the mobile telephone 1 to the other party, and the voice of the other party is received from the mobile telephone 1 by a receiving voice signal input terminal 2a. 2 and the transmission circuit 2f 2 through the speaker 2c. When the earphone / microphone plug 3a is inserted into the handy device, the user's voice input through the microphone 3b of the earphone / microphone 3 is transmitted to the microphone voice signal input terminal 2e. 1 and transmission circuit 2f 3, a transmission voice signal output terminal 2a 1 is transmitted from the mobile telephone 1 to the other party, and the voice of the other party is received from the mobile telephone 1 by a receiving voice signal input terminal 2a. 2
Input to the transmission circuit 2f 4 through the earphone audio output terminal 2e 2 and a transmission switching circuit 2g for generating sound from the earphone 3c in the general earphone microphone
1 and 2g Hands-free device that switches in 2. 2. A microphone sound signal in the mobile telephone 1.
Input terminal 1b 1 and earphone audio signal output terminal 1b
2 is a transmission voice signal output terminal of the hands-free device 2
2b 1 and received voice signal input terminal 2b 2 electrically connected
The hands-free device according to claim 1, which is continued. 3. A microphone audio signal input terminal 2e of the hands-free device 2. 3. The hands-free device according to claim 1, wherein the presence or absence of the earphone microphone is recognized by taking a different value when the voltage at 1 is different from when the earphone microphone plug 3 a of the earphone microphone 3 is inserted into the hands-free device. 4. A microphone audio signal input terminal 1b of the mobile telephone 1. Speech sound signal output terminal 2b in hands-free device 2 electrically connected to 1 1 is a hands-free device that determines that the mobile phone is in use when a voltage higher than a certain value is output from the mobile phone 1.