JPH11164338A - Telephone line connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow all telephone sets to receive service information such as a caller number in the case that plural telephone sets whose transmission timing of a reply signal differs are connected (branched) to a same telephone line. SOLUTION: The connector is configured with a switch 13 that conducts/ interrupts a DC current between a 1st connection terminal 11 connecting to a telephone line 21 and a 2nd terminal 12 connecting to a 2nd telephone set 4, detection circuits 15, 16 that detect a period of a DC loop through which service information from the telephone line 21 is sent, and a control circuit 17 that opens the connection of the switch 13 for a period of DC loop forming based on outputs of the detection circuits 15, 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone line connector used in a system for transmitting service information to a called terminal before transmitting a call signal of a call.

[0002]

2. Description of the Related Art Currently, a caller's telephone (information receiving terminal)
An outgoing telephone number display service (pre-communication information notification service) in which a telephone station (subscriber exchange) informs a telephone of a called party of a telephone number of the telephone number is being experimentally performed in Yokohama, Nagoya and Fukuoka. This is a service that can be provided to the telephone of the called party who is connected to the line subscribed to this service and has a telephone number receiving function, and transmits a telephone number before transmitting an IR (call signal). The processing is added.

[0003] This telephone number sending process will be described with reference to the time chart of FIG. By calling the caller's phone,
The central office inverts the polarities of the two telephone lines L1 and L2. Then, the telephone office performs CAR (information receiving terminal activation signal).
(See FIG. 4) to the called party's telephone. This CAR
The telephone of the called party which has received the ACK sends a primary response signal to the central office by forming a DC loop.

When the telephone station detects the primary response signal, it sends an information signal (caller number) (modem signal) of the telephone number of the calling party telephone to the called party telephone. Upon receiving the modem signal, the telephone of the called party cuts off the DC loop and sends a reception completion signal to the central office. When the telephone station detects the reception completion signal, it determines that the telephone number transmission processing has been completed and transmits a normal call signal (IR) (see FIG. 5).

[0005] In this way, the called party can be notified of the telephone number of the calling party before ringing.

[0006]

However, the method of detecting the CAR and the timing of transmitting the primary response signal after receiving the CAR are not uniform. For this reason, for example, when two telephones are connected to the same telephone line, if one of the telephones first detects the CAR and sends out a primary response signal, the central office determines the C
The transmission of the AR is stopped, and the calling party number is transmitted. For this reason, there is a problem that the calling telephone number is sent to the other telephone before forming the DC loop, and the other telephone cannot display the calling telephone number.

[0007]

SUMMARY OF THE INVENTION A telephone line connector according to the present invention has been made in view of the above point, and a telephone line through which service information is transmitted during a DC loop forming period provided before transmission of a call signal of a telephone call. A telephone line connector connected between the telephone line, a first connection terminal connected to the telephone line, a second connection terminal connected to the terminal, and the first connection terminal A switch for interrupting the DC current between the second connection terminal and the second connection terminal; a detection unit for detecting a period of the DC loop; and a control for opening the connection of the switch during the DC loop formation period based on an output of the detection unit. Circuit. In addition, a first connection terminal connected to the telephone line, a second connection terminal connected to the second terminal, and a DC current between the first connection terminal and the second connection terminal. An intermittent switch, detecting means for detecting the start of the DC loop period, and the connection of the switch is opened based on an output of the detecting means, and the switch is closed after a predetermined time.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a main part of an embodiment of the present invention.

(1) is a telephone line connector of the present invention.
(2) is a telephone station that provides a calling telephone number display service. (3) and (4) are first and second telephones, respectively, both of which have a function of receiving a caller number corresponding to a calling telephone number display service. However, the second telephone sends the primary response signal faster than the first telephone.
When the first and second telephones are directly connected to the line of the central office, the telephone that does not display the caller number is the first telephone (3).

The telephone line connector (1) has first and second connection terminals (11) and (12), a switch (13), a capacitor (14), a primary response detection circuit (15), and a CAR detection circuit ( 16) and a control circuit (17).

The first connection terminal (11) is connected to a telephone line (21) of a central office. The telephone line (21) is a telephone line subscribed to the calling telephone number display service, and the telephone number of the caller is transmitted from the telephone office (9).
A first telephone (3) is connected to the telephone line (21). The second telephone (4) is connected to the second connection terminal (12).

The switch (13) has a first connection terminal (1).
A DC current between 1) and the second connection terminal (12) is opened and closed. Thus, when the switch (13) is open, the second telephone (4) tries to output a primary response signal,
Even if a switch for primary response (a switch for forming a DC loop like a hook switch, not shown) is closed, no linear loop is formed on the telephone line (21), and the primary response signal Not output to line (21).

The capacitor (14) is connected in parallel with the switch (13). Like the IR detection at the time of on-hook, the first connection terminal (1) is connected even when the switch (13) is open.
An alternating current such as CAR or IR can flow between 1) and the second connection terminal (12). That is, the switch (13)
The CAR is input to the second telephone (4) even when is released.

The primary response detection circuit (15) is connected to the first connection terminal (11), detects the formation of a DC loop of the telephone line (21), and outputs this detection signal to the control circuit (17). Here, the detection of the formation of the DC loop is the detection of the primary response signal output from the first telephone (3), and is performed by checking the voltage drop due to the formation of the DC loop.

The CAR detection circuit (16) is connected to the second connection terminal (12), detects the CAR input to the second connection terminal (12), and outputs this detection signal to the control circuit (17).
Output to

The control circuit (17) includes a primary response detection circuit (1).
The switch (13) is released by the detection signal of 5), and CA
Switch (13) according to the detection signal of R detection circuit (16)
Is closed.

Next, the operation of the calling telephone number display service according to the present invention will be described. FIG. 2 is a time chart showing this operation. FIG. 3 is a flowchart showing the operation of the control circuit (13).

In the standby state, the control circuit (17) closes the switch (13) (S1).

Therefore, when there is a call from the caller's telephone, the central office inverts the polarity of the telephone line (21). Then, the telephone station sends a CAR (information receiving terminal activation signal) indicating the start of the calling telephone number display service. This CA
R is a pulse signal composed of High for 0.5 seconds and Low for 0.5 seconds, as shown in FIG. The normal call signal (IR) for calling the called party is a pulse signal composed of High for 1 second and Low for 2 seconds, as shown in FIG. 5, so that CAR and IR can be distinguished.

The control circuit (17) can detect the CAR by the CAR detection circuit (S2). Control circuit (1
7) When the CAR is detected, the switch (13) is released (S3) and the timer is started (S4).

When the switch (13) is released, the second telephone (4) can continue to receive the CAR via the capacitor (14). Upon receipt of the CAR, the second telephone (4) closes the internal primary response switch earlier than the first telephone (3). However, no linear loop is formed because the switch (13) is open. Therefore, since the central office (2) does not send out the caller number yet, the secondary response which is slow in the primary response as in the prior art is not performed.
There is no problem that this telephone (4) cannot display the caller ID.

Behind the second telephone (4), the first telephone (3) also closes a switch for primary response (a switch for forming a DC loop like a hook switch, not shown). Let it. As a result, a straight loop is formed.

When the control circuit (17) starts the timer in step S4, the control circuit (17) determines whether a primary response of the first telephone (3) has been detected via the primary response detection circuit (15) (S5), or It is monitored whether or not has reached a predetermined time (S6). When detecting the primary response, the control circuit (17) closes the switch (13) (S7).

On the other hand, the telephone office (2) is a first telephone (3)
When the primary response is detected, the caller number is sent to the first telephone (3) and the second telephone (4). Switch (1
3) is closed and the first telephone (3), the second telephone
Since the primary response switch is closed, any of the telephones (4) can receive the caller ID. When the reception of the caller is completed, the caller number is displayed. Then, the first telephone (3) and the second telephone (4) release the switch for the primary response. Both phones (3)
(4) When the switch for the primary response is released, the DC loop is cut off and a reception completion signal is output to the central office.
Upon receiving the reception completion signal, the telephone station (2) sends out an IR,
The first telephone (3) and the second telephone (4) will ring the bell for calling. At the time of this sound,
Both the first telephone (3) and the second telephone (4) display the calling party number.

Here, if the first telephone (3) is not connected to the telephone line (2), the switch (13) of the telephone line connector (1) does not receive the primary response signal. Therefore, the second telephone (4) cannot make a call. As a countermeasure, the control circuit (17) closes the switch (13) when the time is up in step S6.

The release of the switch (13) is performed by CA
The detection is performed based on the detection of R, but may be performed based on the detection of the start of the linear loop formation period, such as the detection of polarity inversion and the detection of the primary response signal of the second telephone (4).

When the maximum time difference for outputting the primary response signal of a commercially available telephone is predicted, the telephone line connector (1) does not receive the primary response signal but closes the switch (13) with a timer. It may be tied. In this case, as shown in FIG. 6, the primary response detection circuit (15) in FIG. 1 is omitted, and as shown in FIG. 7, a flowchart in which step S5 is deleted from FIG. 3 is provided, so that an inexpensive telephone line connector can be supplied. it can.

Although the telephone station of the above-described embodiment has transmitted the information of the telephone number of the caller, this service is not limited to the telephone number of the caller, and is not limited to the telephone number of the caller. The present invention can be applied to all the service information transmitted to.

[0029]

When a plurality of telephones with different response signal transmission timings are connected (branched) to the same telephone line, the telephone line connector of the present invention is connected between the telephone line and the telephone line whose transmission timing is earlier. As a result, all telephones can receive service information such as a caller number.

[Brief description of the drawings]

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

FIG. 2 is a time chart illustrating a transmission operation of a calling telephone number display service according to the embodiment.

FIG. 3 is a flowchart illustrating an operation of the control circuit according to the embodiment.

FIG. 4 is a diagram showing a signal waveform of a CAR in a calling telephone number display service.

FIG. 5 is a diagram showing an IR signal waveform in a calling telephone number display service.

FIG. 6 is a block diagram showing a configuration of a main part of another embodiment.

FIG. 7 is a flowchart illustrating an operation of a control circuit according to another embodiment.

FIG. 8 is a time chart showing a transmission operation of a conventional calling telephone number display service.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Telephone line connector 2 Telephone office 3 First telephone 4 Second telephone 11 First connection terminal 12 Second connection terminal 13 Switch 15 Primary response signal detection circuit 16 CAR detection circuit 17 Control circuit 21 Telephone line

Claims (2)

[Claims] 1. A telephone line connector connected between a terminal and a telephone line through which service information is transmitted during a DC loop forming period provided before transmission of a call signal of a call, wherein the telephone line is connected to the telephone line. A first connection terminal, a second connection terminal connected to the terminal, a switch for interrupting a DC current between the first connection terminal and the second connection terminal, and a period of the DC loop. And a control circuit for releasing the connection of the switch during the DC loop formation period based on the output of the detection means. 2. A telephone line connector connected between a terminal and a telephone line through which service information is transmitted during a DC loop forming period provided before transmission of a call signal of a call, wherein the telephone line connector is connected to the telephone line. A first connection terminal, a second connection terminal connected to the terminal, a switch for interrupting a DC current between the first connection terminal and the second connection terminal, and a period of the DC loop. And a control circuit for opening the connection of the switch based on the output of the detection means and closing the switch after a predetermined time.