JPH05122358A - System for informing incoming call to extension subscriber - Google Patents

Abstract

PURPOSE:To immediately and clearly inform an extension subscriber about whether or not an incoming call comes to an outside line or an extension when the extension subscriber is called in the case the call comes from other extension subscriber or through the outside line to the extension subscriber. CONSTITUTION:When a call comes to an extension subscriber 1-1 from a telephone network 9 or an extension subscriber 1-2, a central processing unit 7 detects it and stores it to an incoming call type storage circuit 10 and a busy state detection circuit 4 detects whether the extension subscriber 1-1 is idle or busy. When the extension subscriber 1-1 is idle and the call comes from the telephone network 9 as the result, the central processing unit 7 starts a polarity inversion circuit 2 to invert the polarity of the subscriber line to the extension subscriber 1-1 and not to invert the polarity to the extension subscriber 1-2 in the case of the call therefrom. Then the central processing unit 7 starts a call signal transmission circuit 5 to send a call signal to the extension subscriber 1-1 thereby informing whether the incoming call to the extension subscriber 1-1 comes from the telephone network 9 or the extension subscriber 1-2 to the extension subscriber 1-1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an automatic private branch exchange,
In particular, it relates to an incoming call notification method for extension subscribers.

[0002]

2. Description of the Related Art Heretofore, this type of incoming call notification to an extension subscriber has been used to notify the extension subscriber of the incoming call from the outside or another extension subscriber, depending on the way the call signal is interrupted. It was a method of notifying if there was.

[0003]

The above-mentioned conventional incoming call notification system for extension subscribers, when an extension subscriber receives an incoming call from an outside line or another extension subscriber, sends a call signal to the extension subscriber. There is a drawback in that it is difficult to instantly identify the incoming call type because the incoming call is notified by the method of interruption.

An object of the present invention is to provide an incoming call notification system to an extension subscriber, which instantly notifies the extension subscriber whether the incoming call is an external call or an extension when the extension subscriber calls.

[0005]

According to the method of notifying an incoming call to an extension subscriber of the present invention, when an extension subscriber receives an incoming call from an outside line or another extension subscriber in an automatic private branch exchange, a call type of the incoming call is given. And a means for detecting whether the incoming extension subscriber is idle or busy, and the extension subscriber when the incoming extension subscriber is idle and the incoming call is an external call. Means for reversing the polarity of the subscriber line to
Means for sending a calling signal when the called extension subscriber is idle.

[0006]

The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. When the extension subscriber 1-1 or 2 receives an incoming call from the outside line 9 or another extension subscriber 1-2 or 1-1,
An incoming call type storage circuit 10 for storing the incoming call type;
A busy detection circuit 4 for detecting whether the extension subscriber is idle or busy when receiving an incoming call, and the extension subscriber when the extension subscriber is idle when the incoming call is received and the incoming call is an external call. A polarity reversing circuit for reversing the polarity of the subscriber line to the line, and a ringing signal transmitting circuit for transmitting a ringing signal when the extension subscriber is idle when receiving a call.

When the extension subscriber 1-1 receives an incoming call from the telephone network 9 or the extension subscriber 1-2, the central processing unit 7 detects it and stores the incoming call type in the incoming call type storage circuit 10. At the same time, the busy line detection circuit 4 detects whether the extension subscriber 1-1 is idle or busy.

As a result, when the extension subscriber 1-1 is vacant and an incoming call is received from the telephone network 9, the central processing unit 7 activates the polarity inverting circuit 2 and the polarity of the subscriber line to the extension subscriber 1-1. After inverting, the calling signal sending circuit 5 is activated to send the calling signal to the extension subscriber 1-1 through the line circuit 3-1.

When the extension subscriber 1-1 is vacant and an incoming call is received from the extension subscriber 1-2, the central processing unit 7 does not activate the polarity inversion circuit 2 but activates only the call signal transmission circuit 5. Then, the call signal is transmitted to the extension subscriber 1-1 through the line circuit 3-1.

When the extension subscriber 1-1 receives the ringing signal after receiving the polarity reversal signal, it recognizes that the incoming call is from the telephone network 9, and displays it by a corresponding lamp and ringing tone. Further, when only the ringing signal is received without receiving the polarity inversion signal, it is recognized that the incoming call is from the extension subscriber 1-2, and the corresponding lamp and ringing tone are displayed.

[0012]

As described above, according to the present invention, when an extension subscriber receives an incoming call from an outside subscriber or another extension subscriber,
There is an effect that whether the incoming call is an external line or an internal line can be instantly and clearly notified when the internal line subscriber is called.

[Brief description of drawings]

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

[Explanation of symbols]

 1-1, 1-2 Extension subscriber 2 Polarity inversion circuit 3-1, 3-2 Line circuit 4 Busy detection circuit 5 Ringing signal sending circuit 6 Switch 7 Central processing unit 8 Trunk circuit 9 Telephone network

Claims (1)

[Claims] 1. An automatic private branch exchange, when an extension subscriber receives an incoming call from an external extension or another extension subscriber, a means for storing the call type of the incoming call, and the incoming extension subscriber being busy or busy. Status detecting means, means for inverting the polarity of the subscriber line to the extension subscriber when the incoming extension subscriber is idle and the incoming call is an external call, and the incoming extension subscriber And a means for transmitting a calling signal when the call is idle.