JPH01305753A - Telephone set - Google Patents

Abstract

PURPOSE:To inexpensively secure the safety of a caller by means of a simple circuit by providing a sound volume adjustment means and a sound volume control circuit reducing the sound volume of an earphone input when there is a ringing tone and setting it to a normal call level when the ringing tone stops. CONSTITUTION:If there is a sudden incoming call and there is the ringing tone in a reception sound line 1 when a receiver is waiting for the incoming call by an earphone 5 at the time of a waiting state, a ringing tone detection circuit 10 detects it. The sound volume control circuit 102 operates a variable attenuator 103, and controls the sound volume inputted to the earphone 5 to a level without pain through an amplifier 2 and a switch 3 since the earphone 5 is connected through the switch 3 and a sense line 104. Next, it is controlled that a pleasant reception is executed by returning the attenuator 103 to an original state and reducing an attenuation quantity when it comes to a call state by the off-hook of the receiver and the like. That the attenuator 103 is attenuated until the ringing tone is inputted to the line 1 avoids a moment leaking output from the earphone 5 due to the detection rise and delay of the circuit 101 and that of the circuits 102 and 103 as the operation of the circuit 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a telephone set in which a volume control circuit is added to a receiver circuit.

[Conventional technology]

FIG. 4 is a block diagram of a conventional car phone. In the figure, 1 is a receiving voice line, 2 is an amplifier on the receiving side, and 3
is a switch connected to this, 4 is a receiver connected to one output of the switch 3, 5 is an earphone connected to the other one, and 6 is a speaker connected to the remaining one.

Further, 7 is a transmitter, 8 is an amplifier for amplifying the output signal of the transmitter 7, 9 is a transmission audio line, 10 is an external microphone, and 11 is a switch.

Next, the operation will be explained. In the standby state, normally,
When the earphone 5 is not present, the switch 3 is connected to the speaker 6. In this case, when there is an incoming call, a ringing tone is sent to the receiving voice line 1 and the amplifier 2. Switcher 3
The signal is output from the speaker 6 through the .

Next, when the telephone is picked up and placed in an off-hook state, the ring tone is muted and the voice of the other party can be heard from the handset 4.

When a voice is generated, it undergoes acoustic-to-electrical conversion in the transmitter 7, passes through the switch 11, is amplified by the amplifier 8, and is transmitted to the other party via the transmission voice line 9.

Similarly, when the earphone 5 is in the standby mode, the ring tone is set to the voice line 1. Amplifier 2, switch 3
The information is transmitted from the earphone 5 to the receiver via the .

Next, when the telephone is picked up and placed in an off-hook state, the other party's voice is received through the earphone 5.

For transmitting calls, use the external microphone 10 to switch 11. The signal is sent to the transmitting voice line 9 through the amplifier 8.

[Problem to be solved by the invention]

Because conventional car phones are configured as described above, the ring volume is currently about 20 dB higher than the level at which people normally have a conversation, but in that case, when listening directly through earphones 5, the ring volume suddenly becomes louder. There was a problem in that a loud sound could be heard and the sound would pickle.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a car telephone that can avoid picking up the receiver.

[Means for Solving the Problems] A telephone according to the present invention is provided with a volume control circuit that operates a volume adjustment means when there is a ring tone.

[For production]

The volume control circuit in this invention drives the volume adjustment means to lower the output of the earphone when there is a ring tone, and when the ring tone stops, the volume control circuit releases the drive of the volume adjustment means to a level that allows normal conversation. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 101 is a ringing tone detection circuit sent to the receiving voice line 1, and 102 is this ringing tone detection circuit 1.
A volume control circuit 103 receives the output from the amplifier 2, and a variable attenuator 103 is a variable attenuator as a volume adjustment means operated under the control of the volume control circuit 102.

Further, 104 is a sense line that has a function of detecting whether or not the earphone 5 is connected to the switch 3 and sends the detection to the volume control circuit 102 . The rest of the structure is the same as that in FIG. 4, and the same parts as in FIG. 4 are given the same reference numerals.

Next, the operation will be explained. When the receiver is in the standby state and the earphone 5 is waiting for an incoming call, when a call unexpectedly arrives and there is a ringing tone on the receiving voice line 1, the ringing tone detection circuit 101 detects this, Seeing that the earphone 5 is connected via the switch 3 and the sense line 104,
The volume control circuit 102 operates the variable attenuator 103 to output the amplifier 2. The volume input to earphones 5 is controlled to a painless level through a switch 3.

Next, when the receiver takes the telephone off the hook and enters a talking state, the volume control circuit 102 returns the variable attenuator 103 to its original state and reduces the amount of attenuation, thereby providing control so that the user can receive the call comfortably. .

The function of the volume control circuit 102 is to keep the variable attenuator 103 attenuated until the ring tone is input to the receiving voice line 1, so that the ring tone detection circuit 101
Due to the start-up delay in detection and the start-up delay of the volume control circuit 102 and the variable attenuator 103, it is possible to prevent the ringing sound from leaking and being output from the instantaneous earphone 5.

Although the above embodiment used the ringing tone detection circuit 101, a second embodiment of the present invention in which this circuit is omitted will be described with reference to FIG.

In FIG. 2, reference numeral 201 indicates a control signal line for transmitting various digital data from the radio to the car telephone. The ring tone detection circuit 101 is eliminated, and data indicating that the ring tone is input through the receiving voice line 1 is sent through the control signal line 201, and this is detected by the volume control circuit 102, and is used as a volume adjustment means. The variable attenuators 1 and 03 are attenuated.

The other configurations are the same as in FIG. 1.

In the case of FIG. 2, tone signals other than the ringing tone, such as dial tone and busy tone, are also sent as data and detected by the volume control circuit 102, allowing various volume controls.

FIG. 3 is a block diagram of a third embodiment of the present invention,
In the figure, 301 is a variable amplifier whose amplification degree is changed by the output of the volume control circuit 102 so that the output of the earphone 5 in response to the ringing tone can be set to a comfortable volume.

〔Effect of the invention〕

As described above, according to the present invention, when the earphone is on standby, the ring tone is detected and the volume control circuit drives the volume adjustment means to lower the volume appropriately, so it is relatively simple. This has the effect of making it possible to achieve a safe configuration for the listener at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a car phone according to one embodiment of the invention, FIGS. 2 and 3 are block diagrams showing the configuration of a car phone according to other embodiments of the invention, and FIG. FIG. 1 is a block diagram showing the configuration of a conventional car phone. 1 is a receiving audio line, 2 is an amplifier, 3 is a switch, 4 is a receiver, 5 is an earphone, 6 is a speaker, 7 is a transmitter, 8 is an amplifier, 102 is a volume control circuit, 103 is a variable attenuator (volume adjustment means). In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Figure 2

Claims (1)

[Claims] In a telephone that outputs a ringing tone from a speaker of the telephone and allows the ringing tone to be heard even when an earphone is inserted, a volume adjustment means provided in a path for transmitting the ringing tone to the earphone and adjusting the volume; A telephone set comprising: a volume control circuit that drives the volume adjustment means when the ring tone is transmitted to control the output of the ring tone from the earphone to a comfortable level.