JPH0799676A - Telephone exchange for household - Google Patents

Abstract

PURPOSE:To prevent faulty operations from occuring in an extension telephone set of an automatic answering telephone set or the like connected to a telephone exchange for household by tentatively inverting the polarity of the communication line of the extension telephone set when the communication state of mutually line-connected communication equipment of a calling origin and extension telephone set is ended. CONSTITUTION:Busy tones are transmitted from a signal generation circuit 15 to the extension telephone set T in parallel to intercom communication, however, depending on the machine type of the automatic answering telephone set, a recording operation is not stopped by the detection of the busy tones and the recording operation is stopped by the polarity inversion of the communication line. In this case, when the transmission period of the busy tones is ended, a CPU 8 performs control so as to tentatively invert the polarity of the communication line, that is the polarity of terminals B1 and B2 for connection. The switches of relay switches 6a and 6b are tentatively switched for the tentative polarity inversion. By detecting the polarity inversion by the automatic answering telephone set, the recording operation of the automatic answering telephone set is surely stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used to perform an extension call between extension telephones and a doorphone call between an intercom subunit and an extension telephone, in addition to an outside telephone using a public telephone line. The present invention relates to improvements in home telephone exchanges applied to.

[0002]

2. Description of the Related Art Conventionally, a home telephone switchboard of this kind has been used for an extension telephone when calling an intercom call from an intercom subunit to an extension telephone or when calling an extension telephone call from an extension telephone to another extension telephone. And sends a predetermined ringing signal. Further, as a call signal transmitted to such an extension telephone, a call signal having the same time interval as that of a 16 Hz call signal transmitted from an exchange of a public telephone line network is usually applied. If the extension telephone has a predetermined response operation such as an incoming call operation in response to the calling signal, the extension telephone can be connected to the intercom subunit or extension telephone of the calling source to make a doorphone call or an extension call. When the intercom call and extension call are completed, a busy tone (BT signal) for notifying the fact is transmitted to the extension telephone side.

Further, in the conventional home telephone exchange, FIG.
As shown in (a), the extension telephone T is connected to the two-line type call line L.
Connection terminals B1 and B for connecting via 1, L2
2 is provided with changeover switches 1a and 1b for switching connection between external lines (station lines) La and Lb. Thus, conventionally, the call current supply circuit 2e is fixedly connected to the contact b side of the changeover switch 1a on either side of the changeover switches 1a and 1b. .

[0004]

In many cases, an answering machine is connected as an extension telephone to a home telephone switchboard of this type for use, but this answering machine is used for calling a doorphone call from a home telephone switchboard. Alternatively, an automatic incoming call may occur in response to a calling signal for calling an extension. In such a case, most of the answering machines are generally configured to terminate the recording operation by detecting the busy tone transmitted from the home telephone exchange at the end of the doorphone call or the extension call. However, depending on the model of the answering machine, the recording operation may not be terminated depending on the detection of the busy tone. Therefore, conventionally, there has been a problem in that the answering machine that responds to a call from the intercom subunit or another extension telephone may continue the recording operation unnecessarily even after the end of the intercom conversation.

Further, conventionally, when an answering machine is used as an extension telephone, the answering machine is set to automatically receive an incoming call by receiving a calling signal a small number of times, eg, about 4 times or less, and start a recording operation. In this case, it may unnecessarily respond to a call from the intercom subunit or another extension telephone, and this also causes a problem.

Further, in the conventional configuration shown in FIG. 8A, the polarity of the communication line L1 to which the communication current supply circuit 2e is connected is positive (+), and the polarity of the other communication line L2 is negative (-). However, the polarities of the outside lines La and Lb differ depending on the direction of the outside line connection of the other party's telephone, and for example, the outside line La may be negative (-) and the outside line Lb may be positive (+). In such a case, as shown in FIG. 8B, when the changeover switches 1a and 1b are switched, the communication line L1 is temporarily negative (-) and the communication line L2 is positive (+). The phenomenon that the polarity is reversed occurs. That is, FIG. 9 is an explanatory diagram showing the polarities of the call line L1 with respect to the call line L2. First, the handset of the extension telephone set T is picked up, and after dialing for an outside call, the call lines L1 and L2 are When it is directly connected to the outside line, the voltage value of the communication line L1 becomes temporarily negative at that time (the time of N in the same figure). However, some communication devices include a device (modem or the like) that disconnects the line by determining such a temporary voltage change of the communication line L1 as polarity reversal. Since the original polarity reversal is performed when the other party's communication device responds after that, if the polarity reversal is judged before the other party responds as described above, it is appropriate for the communication device to operate. Cannot be executed,
This point also caused difficulties.

It is an object of the present invention to solve the above-mentioned problems and prevent an extension telephone such as an answering machine connected to a home telephone exchange from malfunctioning.

[0008]

SUMMARY OF THE INVENTION A home telephone exchange according to the present invention, which is proposed to achieve the above object, comprises a calling device and an extension telephone line which are mutually line-connected. Polarity switching means for temporarily reversing the polarity of the call line of the extension telephone is provided when the call state of (1) is finished.

According to another aspect of the present invention, there is provided a home telephone exchange which temporarily supplies power to the extension telephone when the call state between the calling device and the extension telephone connected to each other is terminated. It is provided with a power supply stopping means for stopping the power supply.

According to a third aspect of the present invention, the household telephone exchange according to the present invention, when a predetermined call signal transmitting means transmits a call signal for executing a call other than an outside call to an extension telephone, the call is sent. The signal time interval is configured to be a predetermined time interval that is at least longer than the sending time interval of the ringing signal for executing an outside call.

According to a fourth aspect of the present invention, there is provided a home telephone switchboard according to the present invention, which is a switch for switching and connecting both an outside line and a call current supply circuit to a call line of an extension telephone connected to a connecting terminal. A home telephone switch equipped with a switch, wherein polarity detection means for detecting the polarity of the outside line and the polarity of the extension line detected by this polarity detection means can be matched with the polarity of the extension line telephone line. Polarity switching means for freely switching between positive and negative of the call current supply circuit connected to the switch contact for connecting the call line of the extension telephone of the changeover switch is provided.

[0012]

In the home telephone exchange according to the present invention having the above-mentioned structure, the telephone call state between the extension telephone and the calling communication device (doorphone handset, other extension telephone, etc.) Upon completion, the polarity switching means temporarily reverses the polarity of the telephone line of this extension telephone. Therefore, even if an answering machine of a type that does not stop the recording operation depending on the detection of a busy tone is applied as the extension telephone, as long as this answering machine is of a type that stops the recording operation by detecting the polarity reversal. (An answering machine of this type is also commercially available), and the recording operation state can be appropriately stopped at the time of ending the call.

In the home telephone exchange according to the present invention as defined in claim 2, when the communication state between the extension telephone and the calling device of the calling end is finished, a predetermined power feeding stopping means temporarily feeds power to the extension telephone. Stop. Therefore, even if a type of answering machine that does not stop the recording operation by busy tone or polarity reversal is applied as an extension telephone, by temporarily stopping the power supply to this answering machine, It is possible to forcibly stop the recording operation.

In the home telephone exchange according to the third aspect of the present invention, when the calling signal for executing a call other than the outside call is sent from the predetermined calling signal sending means to the extension telephone, the outside line is sent. The call signal is transmitted at a predetermined time interval that is set longer than the time interval of the call signal when executing a call. Therefore, in a case where an automatic answering type answering machine is applied as an extension telephone and the answering machine is set to perform an automatic answering operation by receiving a relatively small number of ringing signals, for example, about four times or less. However, it takes a long time to make an automatic call to this answering machine. Therefore, it is possible to reduce the risk that the answering machine automatically receives a call other than an outside call from an intercom subunit or another extension phone. Also, as an answering machine, when the ringing signal is not continuously received for a certain period of time or more, the ringing signal previously received is canceled and an automatic incoming call is made only when a certain number of ringing signals are received within a certain period of time. Also exists.
Therefore, in the case of this type of answering machine,
By setting the time interval at which the ringing signal is sent to a long time interval that makes automatic answering of the answering machine impossible,
It is also possible to reliably prevent an answering machine from automatically receiving an incoming call when calling a call other than an outside line call.

In the home telephone exchange according to the present invention as defined in claim 4, the polarity detecting means detects the polarity of the external line and then controls the switching of the positive and negative of the speech current supply circuit connected to the changeover switch. As a result, the polarities of the external line and the communication line can be matched before connecting the communication line to the external line. Therefore, when connecting the call line to the outside line, it is possible to properly prevent the phenomenon that the polarity of the call line is reversed due to the inconsistency of these polarities. It is possible to prevent malfunction of the connected device of the type that causes it.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of a hardware configuration of a home telephone exchange A according to the present invention, and FIG. 2 is a schematic explanatory view showing an outline of a home telephone system configured using the home telephone exchange A. This domestic telephone exchange A has a connection terminal B1 for connecting an extension telephone T,
B2, a terminal B3 for connecting the intercom subunit D, and terminals Ba, Bb for connecting public telephone lines La, Lb as external lines La, Lb are provided. Of these, the extension telephone T is connected to the call line L at the connection terminals B1 and B2.
1, L2 may be directly connected, but may be connected via a telephone outlet 5 equipped with a modular jack 50. A plurality of sets of the connection terminals B1 and B2 are provided, and a plurality of extension telephones T can be connected as needed.

A pair of change-over switches 1a and 1b are provided between the connecting terminals B1 and B2 and the external lines La and Lb. The changeover switches 1a and 1b correspond to the line switching means according to the present invention, and the contact b side is normally closed, and when the extension telephone T is connected to the outside line, the contact a side is closed. Is configured to work. A call current supply circuit 2 for supplying a call current of 24 [V] to the call lines L1 and L2 is wired and connected to the contact points b of the changeover switches 1a and 1b.
In the middle of the wiring, an on / off hook detection circuit 3 for detecting on-hook or off-hook of the extension telephone set T, a DP detection circuit 4 for detecting a dial pulse signal (or push tone signal (DTMF)) sent from the extension telephone set T,
Relay switches 6a and 6b for switching the polarities of the call lines L1 and L2, and a power switch 7 are provided.

Of these, relay switches 6a and 6b
Corresponds to the polarity switching means according to the present invention, and when each contact b side is closed, the changeover switch 1b
Also, the polarity of the call lines L1 and L2 is switched so that the voltage on the call line L2 side is positive and the voltage on the changeover switch 1a and the call line L1 side is positive when each contact a side is closed. . The switching of the contacts of the relay switches 6a and 6b is controlled by the CPU 8.
U8 refers to the communication lines L1 and L2 with respect to the polarities of the external lines La and Lb detected by the polarity detection circuit 9 connected to the external line La.
The relay switches 6a and 6 to match the polarities of
It is configured to switch control b.

The power switch 7 corresponds to the power supply stopping means according to the present invention, and is a normally closed type switch. The power switch 7 is controlled by the CPU 8 from the call current supply circuit 2 to the call line L as described later.
This is for temporarily stopping the power supply to L1 and L2.

The CPU 8 uses the outside lines La and L as described later.
Various signal processing and operation processing for appropriately executing an outside call by the extension telephone T using b, an intercom call between the intercom slave D and the extension telephone T, and an extension call between the extension telephones T and T Is what you do. This CP
U8 includes a polarity reversal detection circuit 10 connected to the outside lines La and Lb, an incoming call detection circuit 11, a doorphone ringing detection circuit 16 connected to a terminal B3 for connecting the intercom subunit D, and a normally closed analog switch 12. , The intercom communication circuit 13, the crosspoint switch 14, the signal generation circuit 15 and the like are connected. Here, cross point switch 14
Is equipped with a plurality of switch contacts that enable switching control of line connection between a plurality of communication devices such as intercom subunit D and extension telephone T. The signal generating circuit 15 is for generating a calling signal, a busy tone, etc., and sending this signal to the extension telephone set T, and corresponds to the calling signal sending means according to the present invention.

Next, C of the home telephone exchange A having the above structure
The specific control operation of each unit by the PU 8 and the operation of the home telephone exchange A will be described. First, when the call switch 17 of the intercom subunit D is pressed to make a call, this is detected by the intercom call detection circuit 16. Then, the CPU 8 drives the signal generating circuit 15 to generate a predetermined calling signal, and the calling signal is transmitted from the connecting terminals B1 and B2 to the extension telephone set T via the cross point switch 14 and the b contacts of the changeover switches 1a and 1b. To send to. However, in this case, as shown in FIG. 3B, unlike the case where the ringing signal is transmitted at a time interval of a short time T1 when a call for an outside line call is made as shown in FIG. In addition, the CPU 8 controls so that the transmission time interval T2 of the calling signal becomes longer than T1.

On the other hand, as the extension telephone T connected to the connection terminals B1 and B2, for example, an answering machine may be applied. However, when the answering machine receives a ringing signal four times in 10 seconds, for example. There is a type that cancels the count of the previously received call signal when the call signal is automatically received and the recording operation is started but the call signal is not received four times continuously within 10 seconds. Therefore,
When an answering machine of this type is used as the extension telephone set T and the sending time interval T2 of the calling signal shown in FIG. 3B is set to, for example, 10 seconds, the answering machine does not automatically receive the incoming call by this calling signal. It is possible to prevent the answering machine from being in a recording operation state during a doorphone call. In addition, such control of the calling signal can be similarly applied when the extension telephones T, T are called each other, and the answering machine is operated only when the call for the outside telephone call shown in FIG. It is possible to make the answering machine not to operate unnecessarily during the call.

Incidentally, as shown in FIG. 4 (b), when a call is called other than an outside call, for example, when the call signal is sent to the extension telephone T once or twice, the call is terminated. Even if there is, it is possible to avoid the automatic answering of the answering machine.

Next, when the call signal control as described above is not performed, an automatic incoming call is made to the answering machine as the extension telephone T in response to the sending of the call signal for intercom communication, and the recording operation is started. There is a case. In such an intercom call, as shown in FIG. 5, at the end stage of the intercom call, which is limited in time to one minute in advance, for example, a busy tone is sent from the signal generating circuit 15 to the extension telephone T in parallel with the intercom call. When the intercom call is terminated after that, the busy tone is transmitted only. Most answering machines stop the recording operation by detecting such a busy tone, but depending on the model of the answering machine, the recording operation does not stop due to the detection of the busy tone, and the communication lines L1, L
Some are configured to stop the recording operation by reversing the polarity of 2.

In the home telephone exchange A according to the present embodiment, when the busy tone transmission timing ends,
Temporarily change the polarities of the call lines L1 and L2 (for example, 0.4 to
The CPU 8 controls to invert it for about 0.8 seconds. This temporary polarity reversal may be achieved by temporarily switching the switches of the relay switches 6a and 6b.
The positive and negative voltages of 1 and L2 are temporarily reversed. Therefore,
By detecting such a polarity reversal by the answering machine, the recording operation of the answering machine can be surely stopped.

A home telephone exchange A according to the present embodiment.
Then, instead of switching the relay switches 6a and 6b to invert the polarities of the communication lines L1 and L2 as described above, the power switch 7 is opened, whereby the communication lines L1 and L2 are opened.
The power supply state for L2 is temporarily (for example, 0.4 to 0.
It is also possible to stop it for about 8 seconds. According to such means, as shown in FIG. 6, after the busy tone is sent to the extension telephone set T after the intercom call is completed, the power supply to the call lines L1 and L2 is stopped, whereby the answering machine is set. The recording operation of will be forcibly stopped. Even with an answering machine of a type that does not stop the recording operation due to detection of a busy tone or polarity reversal, the recording operation can be surely terminated.

Next, the operation control of the extension telephone set T during an outside call will be described. First, the polarity detection circuit 9 connected to the outside line La determines the polarities of the outside lines La and Lb, so that the CPU 8 controls switching of the relay switches 6a and 6b, and the outside lines La and Lb and the communication lines L1 and L2. Are controlled to have the same polarity. That is, when the outside line La is negative (-) and the outside line Lb is positive (+), the contact line L1 is closed by closing the contact b side of the relay switches 6a and 6b as shown in FIG. ), The communication line L2 is set to positive (+). Unlike this, the outside line L
When the polarities of a and Lb are opposite to the above, the contact a side of the relay switches 6a and 6b is closed. In this way, in the state where the polarities of the outside lines La and Lb and the communication lines L1 and L2 match, as shown in FIG. 7, after the dial call is executed in the state where the handset of the extension telephone set T is picked up, the switching is performed. Even if the switches 1a and 1b are switched to directly connect the call lines L1 and L2 to the outside lines La and Lb, the polarities of the call lines L1 and L2 are not reversed. Therefore, it is possible to appropriately prevent the communication device that determines the relative fluctuation of the voltage values of the N communication lines L1 and L2 shown in FIG.

The extension telephone T according to the present invention is not limited to a specific type. For example, in addition to a general commercially available single telephone or answering machine, a telephone attached to a facsimile, a communication device equipped with a modem, etc. It is a broad concept including.

[0029]

As can be understood from the above description, according to the home telephone exchange of the present invention as set forth in claim 1,
Even if an answering machine of a type that does not stop recording operation due to detection of a busy tone is applied as an extension telephone, the recording operation of this answering machine can be appropriately stopped by reversing the polarity of the call line, and the intercom call The effect that it is possible to appropriately prevent a defect in which an unnecessary recording operation is continued due to such reasons as described above is obtained.

According to the present invention as set forth in claim 2, even when the answering machine of the type that does not stop the recording operation by either busy tone or polarity reversal is temporarily applied as the extension telephone, By temporarily stopping the power supply to the answering machine, the recording operation can be forcibly ended, and an extra effect that the unnecessary recording operation can be more surely prevented is obtained.

According to the present invention as set forth in claim 3, even if an automatic incoming call type communication device is applied as an extension telephone,
When calling a call other than an outside line call, this communication device can be prevented from performing an automatic incoming call operation by a call signal, and the communication device can be appropriately prevented from performing unnecessary operations when calling a doorphone or an extension line. The effect of being able to be obtained is obtained.

According to the present invention as set forth in claim 4, the polarities of the outside line and the telephone line can be made to coincide with each other. As a result, it is possible to properly prevent a phenomenon in which the polarity of the communication line is reversed, and it is possible to prevent an erroneous operation of the connected device of the type caused by the polarity reversal.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a hardware configuration of a home telephone exchange according to the present invention.

FIG. 2 is a schematic explanatory view showing an example of a home telephone system configured by using a home telephone exchange according to the present invention.

3 (a) and 3 (b) are time charts showing an example of a ringing signal transmitted from a home telephone exchange according to the present invention to an extension telephone.

4 (a) and 4 (b) are time charts showing another example of the ringing signal transmitted from the home telephone exchange according to the present invention to the extension telephone.

FIG. 5 is a time chart showing an example of changes in the line voltage of the extension telephone.

FIG. 6 is a time chart showing another example of changes in the line voltage of the extension telephone.

FIG. 7 is a time chart showing a change state of the polarity of a communication line.

8 (a) and 8 (b) are explanatory views showing a main configuration of a conventional home telephone exchange.

FIG. 9 is a time chart showing a change state of the polarity of a conventional communication line.

[Explanation of symbols]

 1a, 1b Changeover switch 2 Call current supply circuit 6a, 6b Relay switch 7 Power switch 8 CPU 9 Polarity detection circuit 15 Signal generation circuit D Doorphone subunit L1, L2 Call line La, Lb External line T Extension phone A Home telephone exchange B1 , B2 connection terminal

Claims (4)

[Claims] 1. A connection terminal for connecting an extension telephone via a telephone line, a call signal transmitting means for transmitting a call signal from the connection terminal to the extension telephone, and transmission of the call signal. A home telephone exchange equipped with line switching means for connecting the extension telephone to the calling communication device when a predetermined response is received from the extension telephone in response to A home telephone exchange characterized by comprising polarity switching means for temporarily reversing the polarity of the call line of the extension telephone when the call state between the called calling device and the extension telephone ends. . 2. A connection terminal for connecting an extension telephone set via a call line, a call signal transmission means for transmitting a call signal from the connection terminal to the extension telephone set, and the transmission of the call signal. A home telephone exchange equipped with line switching means for connecting the extension telephone to the calling communication device when a predetermined response is received from the extension telephone in response to A home telephone exchange, comprising a power supply stopping means for temporarily stopping power supply to the extension telephone when the call state between the called calling device and the extension telephone ends. 3. A connection terminal for connecting an extension telephone via a telephone line, a call signal transmitting means for transmitting a call signal from the connection terminal to the extension telephone, and transmission of the call signal. A home telephone exchange equipped with line switching means for connecting the extension telephone to the calling device when a predetermined response is received from the extension telephone in response to the call signal transmission. When a calling signal for executing a call other than an outside call is sent to the extension telephone by the means, the time interval of the calling signal is at least longer than the sending time interval of the calling signal for executing the outside call. A home telephone exchange characterized by being configured to have a time interval of. 4. A connection terminal for connecting an extension telephone set via a call line, and an external line and a call current supply circuit are switched and connected to a call line of an extension telephone set connected to this connection terminal. A home telephone exchange equipped with a changeover switch for switching the polarity of the outside line and a polarity detection means for detecting the polarity of the outside line, and the polarity of the outside line detected by this polarity detection means can match the polarity of the extension line telephone. In order to achieve this, there is provided a polarity switching means for freely switching between positive and negative of the call current supply circuit connected to the switch contact for connecting the call line of the extension telephone of the changeover switch, and a home telephone exchange. .