JPH066839A - Telephone set with talking maintenance function - Google Patents

Abstract

PURPOSE:To realize the telephone set with a talking maintenance function in which the talking state is maintained without interruption on the occurrence of a power failure during talking. CONSTITUTION:A telephone set with a talking maintenance function 10 is made up of a master set 11 connecting to 6 external lines 1-6 and telephone sets (pushbutton telephone sets) 12-17 connecting to the telephone set 10 corresponding to the external lines 1-6 and the master set 11 is provided with a series circuit 21 comprising a transformer 19, a cross point 18, a transformer 19, a bypass circuit 22 connected in parallel with the series circuit 21 and bypassing the series circuit 21 by a relay contact 20b which are connected between each external line and each telephone set and a control circuit controlling the operation of each device. Since the control circuit closes the relay contact 20b on the occurrence of a power failure during talking with a prescribed software processing, the bypass circuit 22 forms a loop interconnecting between the telephone set 12 and the external line 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone device with a call maintaining function, which has at least one telephone connected to an outside line through a main unit and has a function of maintaining the call state during a power failure during a call. It is a thing.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
Telephone device comprising a telephone 32 connected to an outside line 31 via a telephone
In 33, the crosspoint 34 in the main device 30 is in the OFF state indicated by a circle in the figure when not in a call, and when a call is made, a current flows through the crosspoint 34 by pressing an outside line button (not shown). Cross point 34 is the same figure (b)
Since the ON state shown by the mark ●, the external line 31
A call loop is formed between the telephone 32 and the telephone 32, and a call can be made in that state.

[0003]

In the above-mentioned conventional example, when a power failure occurs during a call, the power of the main unit 30 is cut off and the current does not flow to the cross point 34, so that the cross point 34 is switched from ON to OFF. As a result, the call loop is broken by returning to the state shown in FIG.
This causes a problem that the call is cut off.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a telephone device with a call maintaining function, which can maintain the call state without being cut off when a power failure occurs during a call.

[0005]

To this end, a telephone device with a call maintaining function according to the present invention is provided with a main unit to which at least one outside line is connected, and to the main unit in correspondence with the outside line. A telephone device for making an outside line call by the telephone, and further comprising a call state maintaining means for connecting between the telephone and the outside line during the outside line call to maintain the call state at the time of a power failure. It is a thing.

[0006]

According to the present invention, when a telephone call is made to an outside line by a telephone connected to at least one outside line in correspondence with the main unit, the call state is maintained when a power failure occurs. Since the means operates to connect the telephone and the outside line during the outside call, the call state is maintained, and the call is not disconnected due to the power failure during the call.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing the configuration of a first embodiment of a telephone device with a call maintaining function according to the present invention, and FIGS. 2A to 2D are diagrams for explaining the call state maintaining principle of the same example. . The telephone device 10 with a call maintaining function is composed of a main device 11 to which six external lines 1 to 6 are connected, and telephones (for example, key telephones) 12 to 17 connected to correspond to the external lines 1 to 6, The main unit 11 includes a series circuit 21 of a transformer 19, a crosspoint 18, a transformer 19 and a relay contact (a contact that is closed when the relay is excited and is always excited) 20a connected between each outside line and each telephone. , Is connected in parallel to the series circuit 21 and the series circuit 21 is a relay contact (a contact that opens when the relay is excited)
And a bypass circuit 22 for bypassing by 20b. Although the number of outside lines is 6 in this example, it may be 6 or less or 6 or more (at least one is sufficient).

In the main device 11, each device is supplied with power from a power supply device (not shown), and a control circuit (CP) (not shown) is supplied.
U, memory, etc.). In addition, a relay body (coil) (not shown) for switching the relay contacts is also supplied with power from the power supply device. Further, each cross point 18 is in the OFF state (shown by O) shown in FIG. 1 when the outside line button (not shown) is not pressed on the telephones 12 to 17, and when the outside line button is pressed, it is not shown in the main device. It is turned on by the operation of the relay (shown by ● in FIG. 2 (b)). It should be noted that the transformer 19 has impedance matching (matching) between the external line and the main device internal element and between the telephone and the main device internal element when the series circuit 21 connects the external lines 1 to 6 and the corresponding telephones 12 to 17. ) Is for doing.

Next, the operation of the above embodiment will be described with reference to FIGS. First, when not in a call, the cross point 18 is OFF as shown in FIG.
Since it is in the state, both the series circuit 21 and the bypass circuit 22 in the main device 11 are open, and the telephone and the outside line are disconnected from each other. In this state, for example, when the telephone 12 is operated to raise the handset and press the outside line button, a current flows through the crosspoint 18, and as shown in FIG. 2B, the crosspoint 18 is turned on and the series circuit 21 Forms a loop connecting the telephone 12 and the outside line 1 to enable a call.

In this state, if a power failure occurs during a call, as shown in FIG. 2 (c), the contact 20a of the relay is opened by turning off the power, and the cross point 18 that has been cut off from the current is turned off. Then the series circuit 21 is opened. However, as soon as the contact 20a of the relay is opened, the contact 20b of the relay is closed as shown in the drawing, so that the bypass circuit 22 forms a loop connecting the telephone 12 and the outside line 1. As a result, even if a power failure occurs during a call, the call is not cut off and the call state is maintained.

After that, when the power failure is restored, the control circuit of the main unit 11 executes the control program of FIG. 3, for example, after the restoration to restore the crosspoint 18 to the state before the power failure. Relay contact 20
2 is opened and the bypass circuit 22 is cut off, and finally FIG.
The state of (d) is obtained. That is, in FIG. 3, it is determined in step 50 that the power failure is restored, and if it is determined that the power is restored, the relay contact 20a is turned on in step 51, and the off-hook signal from the telephone and the telephone number of the telephone are determined in step 52. Read the signal that represents. Note that these signals are read by the data lines (not shown) other than the two communication lines shown.

In the next step 53, it is determined whether or not there is an off-hook signal. If there is no off-hook signal, it means that the handset is placed, and the control ends. On the other hand, if there is an off-hook signal, it means that the call is continuing, and the cross point corresponding to the telephone number (12 in this case) (in other words, the outside line 1 in the call) is turned on in the next step 54. Then, in step 55, the relay contact 20b is switched from the ON state shown by the dotted line to the OFF state shown by the solid line to cut off the bypass circuit 22. As a result, the normal call state shown in FIG. 2B is restored. In the above control, there is a state where the ON state of the relay contact 20a and the ON state of the relay contact 20b overlap each other. Therefore, the series circuit in the main device 11
21 and the bypass circuit 22 are not opened at the same time, and the call state is maintained during the processing on this software. Therefore, in the control program of FIG. 3, the control circuit and the relay contacts 20a and 20b function as a call state maintaining means.

Even after the telephone call at the time of power failure is terminated, since the outside line and the telephone are in the connected state as shown in FIG. 2 (c), the next telephone call is possible at the time of power failure in the present invention. Needless to say.

In the circuit of FIG. 1, it is possible to omit the contact 20a which operates by the constant excitation of the relay. In that case, the same operation as above is performed by executing the control program of FIG. 3 except for step 51.

[0015]

As described above, according to the present invention, when a power failure occurs during a telephone call, the telephone call state maintaining means operates to connect the telephone during an outside line telephone call and the outside line. The call will be maintained, and the call will not be disconnected due to a power failure during the call.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a telephone device with a call maintaining function of the present invention.

2A to 2D are views for explaining the operation of the example.

FIG. 3 is a control program showing a crosspoint restoration process when a power failure is restored by a control circuit in the main unit of the same example.

4A and 4B are diagrams for explaining a conventional technique.

[Explanation of symbols]

 1 to 6 Outer line 10 Telephone device with call maintenance function 11 Main device 12 to 17 Telephone 18 Crosspoint 19 Transformer 20a Relay contact 20b Relay contact 21 Series circuit 22 Bypass circuit

Claims (1)

[Claims] 1. A telephone device comprising a main unit to which at least one external line is connected and a telephone connected to the main unit so as to correspond to the external line. A telephone device with a call maintaining function, characterized by comprising a call condition maintaining means for connecting a telephone during a call and an outside line to maintain the call condition.