JPH0158720B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device that also uses an extension individual call information line for transmitting incoming call information from a central office line.
In particular, the present invention relates to a key telephone device which is capable of independently making an extension call and a central office line incoming call even if individual extension calling information and central office line incoming information are generated at the same time.

Conventionally, a key telephone device that uses an extension individual call information line for transmitting incoming call information from a central office line has been constructed as follows. FIG. 1 is a diagram showing the circuit configuration of the device. In the figure, reference numeral 1 denotes a key telephone main device, which includes a plurality of central office line circuits 11a, which operate in response to a central office line (not shown) when an incoming call occurs on that central telephone line.
~, 11n and these station line circuits 11a, ~, 1
It has a central office line incoming information sending circuit 12 which generates central office line incoming information and sends it to desired extension individual calling information lines 2a, . The key telephone main device 1 also includes first and second ring signal source circuits 13a and 1 which generate different ring signals.
3b, the switch 14a of the first paging signal source circuit 13a is closed by the signal generated from the central office line circuits 11a, 11n when a telephone call is received, and the paging signal generated by the paging signal source 15a is thereby closed. is sent to the calling signal line 3 via the amplifier circuit 16. Further, when individual extension call information is sent to the extension individual call information lines 2a, -, 2m from each button telephone, which will be described later, this information is sent to the OR gate circuit 17.
and leads to the second paging signal source circuit 13b via the gate circuit 18, whereby the switch 14
b is closed, and the calling signal generated by the calling signal source 15b is sent to the calling signal line 3 via the amplifier circuit 16. Here, the gate circuit 18 is in a gate closed state during the generation period of the signal generated from the office line circuits 11a to 11n at the time of receiving a call from the office line, so that the gate circuit 18 is in the gate closed state during the generation period of the signal generated from the office line circuits 11a, 11n, and 11n. 2
This is to prevent the calling signal source circuit 13b from operating.

On the other hand, reference numerals 4a, .
These button telephones 4a, -, 4m send extension individual call information to extension individual call information lines 2a, 4m, respectively.
~, 2m Extension call switch circuit 41
and an amplifier circuit 42 for amplifying the calling signal sent from the key telephone main device 1 via the calling signal line 3.
It has This amplifier circuit 42 is allowed to operate only when the extension individual calling information for itself is sent via the extension individual calling information lines 2a, 2m, and supplies the amplified calling signal to the speaker 43. It is generating a ringtone. Note that HS of the extension call switch circuit 41 is a switch, and BK1, BK2, . . . , BKm are extension selection switches. Further, in the figure, reference numerals 5a and 5b indicate power supply lines for supplying power output to each button telephone set 4a to 4m.

However, in such a button telephone device, when an incoming call occurs on a central office line, the corresponding central office line circuit 1a,
The relay contacts r ₁ and r ₂ of ~, 1n are closed, and a calling signal is sent from the first calling signal source circuit 13a, and at the same time, the office line incoming call information sending circuit 12 releases the extension individual calling information lines 2a, ~, The office line incoming information is sent to 2m. As a result, each button telephone 4a, ~, 4
An incoming call is made to ``m'', and the call can be made by turning on the switch HS. At this time, the gate circuit 18 of the key telephone main device 1 is in the gate closed state, so the extension individual call information line 2a,
A ring signal for calling an extension is not transmitted to each key telephone 4a, 4m, guided by the office line incoming information sent to 2m or the second ring signal source circuit 13b. When making an extension call, close the switch HS on the button telephone that will be the calling party, and then press the extension selection button BK1, ~, corresponding to the button telephone to be called.
Close BKm and send extension individual call information to information line 2a,
~,2m. Then, the extension individual calling information activates the amplifier circuit 42 of the key telephone set to be called, and is guided to the second ring signal source circuit 13b via the OR gate circuit 17 and the gate circuit 18,
A calling signal is applied to the amplifier circuits 42 of a to 4m. As a result, the speaker 43 of the key telephone to be called rings to notify that an extension call has occurred. Then, by closing the switch HS, it becomes possible to make a call between the two button telephones. However, if the button telephone device is as above,
Individual extension calls and station line terminating calls can be made respectively.

However, with such conventional key telephone devices, when an incoming call occurs on the central office line during an individual extension call operation, the
Since the gate circuit 18 is closed by the signals from the central office line circuits 1a, . It was happening.
Furthermore, while a call was being made due to an incoming call from the central office line, it was not possible to make an extension call at all.

By the way, recently, the second paging signal source circuit 13
Instead of the call signal source 15b of b, a so-called voice call system is used in which the telephone lines of the key telephones 4a to 4m are connected to give gathering commands and simple business communications. However, even if the above-mentioned conventional device has the above-mentioned voice calling system function, the above-mentioned function cannot be used at all during an incoming call on the central office line, so it cannot fully meet the demands of the subscriber. This was not possible and improvements were desperately needed.

The present invention has been made focusing on the above circumstances,
The purpose of this is to enable incoming calls to central office lines and individual extension calls to be made using a single ring signal line.
Moreover, when these calls conflict, it is possible to notify the corresponding key telephone of the conflict, thereby providing a key telephone device with a small number of wires and high calling performance.

The present invention provides each ring signal generated from a first ring signal source for incoming office line calls and a second ring signal source for individual extension calls to a plurality of key telephones via a single ring signal line. In addition, a call information selection means is provided, so that when there is a conflict between an incoming call on the central office line and an individual extension call, the first switch is driven in response to the incoming call on the central office line, and the first calling signal is transferred to the calling signal line. At the same time, the call information selection means supplies the extension individual call information of the office line incoming call information and the extension individual call information output to the extension individual call information lines to the second switch. The calling signal is configured to be sent to the calling signal line together with the first calling signal.

An embodiment of the present invention will be described below with reference to FIG. Note that the same parts in FIG. 2 as in FIG. 1 are given the same reference numerals, and detailed explanations will be omitted.

In FIG. 2, the station line incoming information sending circuit 12 is provided with a constant voltage circuit 7 that defines the signal level of the station line incoming information. This constant voltage circuit 7 is composed of a Zener diode, and sets the signal level of the central office line incoming information to be somewhat lower than the signal level of the extension individual paging information.

On the other hand, the extension individual call information sent to the extension individual call information lines 2a to 2m is transmitted to the OR gate circuit 1.
7, the signal is introduced into the level discrimination circuit 8, and then supplied to the second paging signal source circuit 13b. The level identification circuit 8 is comprised of a Zener diode 81 and a buffer circuit 82 for identifying the signal level of introduced information.
The extension individual paging information is selectively extracted from the extension individual paging information and the office line incoming call information based on the magnitude of the signal level, and is supplied to the second paging signal source circuit 13b.

With such a configuration, even if an incoming call occurs on the office line during an extension call, the incoming call information on the office line is blocked by the level identification circuit 8, and the office line circuits 11a, . . .
The signal supplied from 11n to the first paging signal source circuit 13a does not cut off the supply path of the extension individual paging information to the second paging signal source circuit 13b. Therefore, even after the arrival of a call on the central office line, the individual extension calling operation continues, and the incoming call on the central office line is also called at the same time. On the other hand, even if an individual extension call is made during an incoming call on the central office line, the individual extension call information is supplied to the second ring signal source circuit 13b via the level identification circuit 8.
An individual extension call is also made at the same time. In addition, the incoming call information on the central office line is specified at a small level and is sent to each button telephone 4.
a, ~, 4m, but if the signal level is set to a value that allows the information input transistor 44 of the amplifier circuit 42 to operate sufficiently, the button telephone 4
There is no problem in the operation of a, ~, 4m.

In this way, according to the device of this embodiment, since the incoming call to the central office line and the incoming call to the extension are carried out through a single ringing signal line, the key telephone main device 1 and each of the key telephones 4a to 4m can be connected to each other. The number of connecting wires between the two can be minimized. Furthermore, even if a central office line incoming call and an individual extension call conflict, they can be performed simultaneously without stopping one of the calls, and at that time, the corresponding key telephone can be notified of the conflict. Therefore, the key telephone operator who receives the individual extension call can answer the extension call,
This allows you to reliably transition to an extension call. Further, at this time, the key telephone is notified that the central office line incoming call and the extension individual call are in conflict, so the operator of the key telephone can select one of them and respond. Furthermore, with the device of this embodiment, the extension hand-free response function, which has become rapidly popular in recent years, can be used freely without any restrictions.

Note that the present invention is not limited to the above embodiments, and various modifications are possible.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional button telephone device, and FIG. 2 is a circuit diagram of a button telephone device according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Button telephone main device, 2a, ~, 2m... Extension individual call information line, 3... Call signal line, 4a, ~, 4
m...button telephone, 11a, -, 11n...office line circuit, 12...office line incoming call information sending circuit, 13a...first
13b...Second calling signal source circuit, 7... Constant voltage circuit, 8... Level identification circuit.

Claims (1)

[Scope of Claims] 1. Calling within a key telephone by transmitting extension individual calling information and central office line calling information using an extension individual calling information line provided between a button telephone main device and a plurality of key telephones. A button telephone device that drives a signal amplification circuit to make a call includes: a first ring signal source that generates a first ring signal that indicates that an incoming call has occurred from a central office line; a second paging signal source that generates a second paging signal; a paging signal that derives and outputs each of the first and second paging signals generated from the first and second paging signal sources; deriving means, commonly connected to the ringing signal amplification circuits of the plurality of button telephones, and transmitting each of the first and second ringing signals output from the ringing signal derivation means to the ringing signal amplification circuits of the plurality of button telephones; a paging signal line that is provided between the first paging signal source and the paging signal deriving means, the paging signal line is connected in response to an incoming call from the central office line, and the paging signal line is connected to the paging signal line generated from the first paging signal source. a first switch that outputs a first calling signal to the calling signal deriving means; and a first switch that is provided between the second calling signal source and the calling signal deriving means, and outputs extension individual calling information via the extension calling information line. a second switch that becomes conductive when supplied with the second call signal source and outputs a second call signal generated from the second call signal source to the call signal deriving means; and a paging information selection means that detects a signal level difference between the incoming call information from the central office line and the individual extension paging information and supplies only the individual internal paging information to the second switch, When there is a conflict with an extension call from the key telephone, the first switch is made conductive in response to the incoming call from the central office line to send the first ring signal to the ring signal line, and the extension Out of the office line incoming call information and the extension individual call information output to the individual call information line, the extension individual call information is supplied to the second switch by the call information selection means to make the second switch conductive. A button telephone device characterized in that the button telephone device is configured to send a calling signal together with the first calling signal to the calling signal line.