JPH0662091A - Telephone set - Google Patents

Abstract

PURPOSE:To automatically cut off a telephone line when the on-hook of a handset is not performed correctly. CONSTITUTION:When the handset 7 is not off-hooked correctly, a busy tone is sent to and detected by a busy tone detection circuit 10 via the telephone line 1, a cutoff circuit 3, a hook switch 4, a dial circuit 5, and a speech circuit 6, and a control circuit 12 cuts off the telephone line by starting up the cutoff circuit. An incoming call detection circuit 2 is connected to the telephone line even in such a state, which enables the next incoming call to be detected. When the handset is off-hooked correctly, the control circuit restores the cutoff circuit. Even when a speech oponent cuts off the line after a user depresses a holding switch 9, and the handset is off-hooked while holding the telephone line, and the hook switch 4 is set in an on-hook state, a busy signal can be sent from an exchange similarly. Even in such a case, no busy tone is detected similarly as in the above mentioned case. In the case of a howler tone, when it is detected at a howler tone detection circuit 11, the control circuit performs the release of the holding circuit 8 and the cutoff of the telephone line.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to telephones.

[0002]

[Prior art] and

The conventional telephone has a structure in which the line is disconnected by hooking the handset after the call. Therefore, if the handset is not placed correctly, the line may not be disconnected and a howling noise may be received from the exchange.

Further, since the conventional telephone has a structure in which the handset can be placed in the hold state, the call partner may be disconnected due to forgetting to release the hold state, and a busy tone may be received from the exchange. In this case, even if the busy tone from the exchange is detected, the hold state is not automatically released, so the howler tone is received from the exchange after a while. In any of the above cases, the conventional telephone has a problem that the reception of the howler sound cannot be stopped unless the user correctly hooks the handset on the hook again.

[0004]

A telephone according to the present invention has a busy tone detecting circuit for detecting a busy tone sent from an exchange when a calling party goes on-hook while on hold, and a handset is off-hook. And a howler sound detection circuit that detects howler sound sent from the exchange, and line control that automatically releases the hold state and disconnects the telephone line by detecting either the busy sound or the howler sound. Have means.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, this embodiment detects a ringing tone detecting circuit 2 for detecting a ringing tone from a telephone line 1, a disconnecting circuit 3 for disconnecting the telephone line 1, and an on-hook and an off-hook of a handset 7. A hook switch, a dial circuit 5 for sending a dial signal, a call circuit 6 for voices transmitted and received, a hold switch 9 for setting the embodiment to a hold state, and a hold circuit 8 for holding the telephone line 1 in a hold state.
A busy sound detection circuit 10 for detecting a busy sound from the telephone line 1, a howler sound detection circuit 11 for detecting a howler sound from the telephone line 1, and a control circuit 12 for controlling the entire telephone of this embodiment. It has and is configured.

Next, the operation of this embodiment will be described.

Normally, the disconnect circuit 3 is not working and the telephone line 1 is connected to the hook switch 4.

During a telephone call, the hook switch 4 is in an off-hook state, the telephone line 1 is connected to the telephone call circuit 6 via the dial circuit 5, and the telephone handset 7 is making a telephone call.

The user puts the handset 7 on completion of the call, but if the handset 7 is not placed correctly, a busy tone is sent from the exchange. Busy tone is telephone line 1, disconnection circuit 3, hook switch 4, dial circuit 5, call circuit 6
Is sent to the busy tone detection circuit 10 and detected. Upon detection of the busy sound, the control circuit 12 causes the disconnection circuit 3
To disconnect the receiving line 1. Even in this state, the incoming call detection circuit 2 is connected to the telephone line 1 and can detect the next incoming call. When the handset 7 is correctly placed, the control circuit 12
Restores the disconnection circuit 3.

When the user pushes the hold switch 9, the hold circuit 8 holds the telephone line 1 and places the handset 7, the hook switch 4 goes on-hook, and then the other party disconnects, the exchange is also operated. Sends a busy signal. In this case as well, a busy tone is detected as in the above case.

As described above, normally, the telephone line 1 is automatically disconnected by the detection of the busy tone, but the busy tone from the exchange is not sent out for a certain period of time, so the busy tone detection circuit 10 does not detect it. There are cases. In order to deal with this situation, the telephone according to this embodiment includes the howler sound detection circuit 11.

After the busy tone is no longer sent, a howler sound is sent from the exchange at regular intervals. The howler sound is detected by the howler sound detection circuit 11 along the same path as the busy sound.
Is transmitted to and detected. The control circuit 12 activates the disconnection circuit 3 or releases the hold circuit 8 in the same manner as in the case of the busy tone, and disconnects the telephone line 1.

[0015]

As described above, the present invention detects the busy sound or howler sound sent from the exchange,
By having the line control means for activating the line disconnecting circuit and releasing the hold state, there is an effect that the user can automatically disconnect the telephone line without returning the handset correctly.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 telephone line 2 incoming call detection circuit 3 disconnection circuit 4 hook switch 5 dial circuit 6 communication circuit 7 handset 8 hold circuit 9 hold switch 10 busy sound detection circuit 11 howler sound detection circuit 12 control circuit

Claims (1)

[Claims] 1. A busy tone detection circuit for detecting a busy tone sent from an exchange when a call partner goes on-hook while on hold, and a howler tone sent from the exchange when the handset is off-hook. And a line control means for automatically releasing the hold state and disconnecting the telephone line by detecting one of the busy tone and the howler tone.