JP2637087B2 - Telephone system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a telephone system.

[Background Art] Conventionally, as this type of telephone system, there is a general single telephone or a system called a home telephone by connecting a door phone to a simple PBX. Since the incoming call is displayed by the ringing function, it is difficult to distinguish between an incoming call from an outside line, an extension, and a door phone. In addition, in a call between a general single telephone connected to an extension, a function for directly transmitting a message to the other party without generating a ringing tone cannot be configured. There was the inconvenience of not being able to communicate.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a telephone system.

[Disclosure of the Invention] The present invention will be described with reference to examples.

Embodiment FIG. 1 shows an entire configuration of an embodiment of a telephone system according to the present invention. This embodiment enables an extension call, and an external line 2 from a central office and a door phone are provided in a main apparatus 1. 3
Is connected as an external line, and a plurality of sets of internal lines including an internal line 5 and a control line 6 are connected. Telephone outlets 10 ₁ ... Are connected to each internal line.

FIG. 2 is a circuit block diagram of an embodiment of the main apparatus 1. In the lines L ₁ and L ₂ constituting the outside line ₂ , an incoming signal detecting section 7 for detecting an incoming signal, a hold circuit 8, and a push button The switching contacts 20 of the external line switching relays Ry ₁₁ ... Provided respectively for the four-line telephone outlets 10 ₁ ... Provided for connecting to the coupling transformer 9 for extracting a signal and for connecting to the internal line. ₁₁ ... b contact and hook / dial pulse detector 30
₁ … connected.

The main device 1 doorphone 3 ₁ ... of connecting a call line 4 connecting and terminal 12 ₁ ... a plurality of, in 12 ₁ ... each of the connecting terminals respectively intercom 3 ₁ ... call signal detector 14 ₁ ... and back The tone transmission units 15 ₁ … are connected and the doorphone switching relay Ry ₂ is connected.
Are connected to the door phone communication circuit 13 through the switching contact 16 of the first embodiment. Door phone call circuit 13 is a door phone call connection relay Ry ₃
Each extension connection to the relay contact 17 and the telephone wall outlet 10 ₁ ... are provided corresponding relay Ry _411, Ry ₄₁₂ ... relay contacts 18 _11, 18 ₁₂ ... and the external line through a capacitor 19 ₁ ... DC blocking It is connected to the switching relay Ry ₁₁ ... of switching contact 20 ₁ ... a contact point of the. The above relay contact 17 and relay contact 18 ₁₁ ... connection point is connected to the output of the sound source generating portion 23 via the relay contact 21 ₁ and the DC cut capacitor 22 of another extension connected relay Ry _51. Further output above back tone sending unit 15 via a capacitor 22 of the sound source generating portion 23 ₁ ..., it is connected to a telephone outlet I / F audio amplifier 24, further the relay contacts 21 _{and second} extension connection relay Ry ₅₂ each The relay contacts 18 ₁₂ are connected to the connection points of the relay contacts 18 ₁₁ and the capacitors 19 ₁ through the relay contacts 18 ₁₂ .

The output of the telephone outlet I / F audio amplifier 24 is connected to the DC cut capacitor 26 and the relay contacts 25 _{1 of the} extension calling relays Ry6 ₁ … provided corresponding to the respective telephone outlets 10 ₁ ….
It is connected to a terminator connection terminal corresponding to each telephone outlet 10 ₁ ... line L ₃ of the control line 6 of the through.

The control circuit 11 composed of a CPU performs control processing of the driver transistor of each relay and sound selection of the sound source generation unit 23,
Control of the back tone transmitting sections 15 ₁ , control of the hold circuit 8 and the hold tone generating section 29, determination of the incoming call detection signal of the incoming call detection section 7, determination of the call signal of the call signal detection sections 14 ₁ ,. The detection of the detection signal of the dial pulse detecting section 30 ₁ ... Or the push button dial signal receiving section 31 is performed. In the figure, I ₁ ... Are extension current supply sources.

The telephone outlets 10 ₁ ... Have a modular jack 45 connected to the lines L ₁ and L ₂ of the extension 5, and a capacitor 47 is provided between the lines L ₃ and L ₄ of the control line 6 as shown in FIG. And speaker 4
8 and the series circuit are connected. The speaker 48 is the control line 6
Sound from the main unit 1 to the lines L ₃ and L ₄ , it is possible to notify the incoming call from the intercom 3 ₁ ... And the call of the extension 5, and is superimposed on the control line 6 at the time of the extension call. It is designed to be able to play the incoming call voice.

 Next, the operation of the telephone system of this embodiment will be described in more detail.

FIG. 4 shows the configuration of the control program of the main device 1. The major processes are divided into three groups: initialization at system startup, input processing, and output processing. It is shown in FIG. Initialization is further divided into I / O / memory initialization and interrupt / timer initialization. In the initialization of the I / O memory, an initial value is set in the memory inside the control circuit 11. That is, the control circuit 11 manages the state of the general single telephone set T connected to each telephone outlet 10 ₁ .
The main operation is to set various state variables, and the initial value set in the memory is to initialize these variables. I / O initialization is to set the incoming call display and control of each relay to the initial state.

The interrupt / timer initialization sets the related functions of the control circuit 11 so that the interval interrupt for the periodic access of the input signal and the control of the time element can be used.

The input process is a process for controlling the state variables held in the memory of the control circuit 11 in accordance with the occurrence of various input events, and the flowchart is shown in FIG. The input processing further includes a hook-on / off processing shown in FIGS. 7 (a) and (b), a dial input processing shown in FIG. 8, an outside-line incoming call processing shown in FIG. 9 (a), and FIG. It is classified into the intercom call processing shown in b).

Here, in the input processing, a hook dial pulse detector detects a hook on / off of the connected general single telephone T.
30 ₁ Detected by (or push button dial signal receiving unit 31). Then, the control circuit 11 determines that the hook-off has occurred when the first rising of the detection signal shown in FIG.
The hook-off process shown in FIG. 7A is performed. That determines whether the incoming call from the outside line 2 in this process, a process in external 2 call if the incoming call, if not the incoming call to determine if the door phone 3 ₁ ... during call, in call If there is, the process during the call with the intercom 3 ₁ ... Is determined whether the call is being made between the extensions 5 if the call is not being made, and if the call is being made, the process during the call between the extensions 5 is being further called. If not, determine whether outside line 2 is available,
If the outside line 2 is usable, the process during the call of the outside line 2 is performed, and if not, the process during the call between the inside lines 2 is performed. Therefore, if there is no call for extension 5 or an incoming call to an outside line or a call to a door phone, the extension 5 connected to the telephone set T is connected to the outside line 2 simultaneously with the hook-off.

If there is the final fall, it is determined that the hook is on, and whether or not the outside line 2 is in use is determined by this determination. If the outside line 2 is in use, the outside line 2 is released. , To determine whether extension 5 is in use,
If during the use of the extension 5 of the opening of the extension 5, or in a unless the intercom 3 ₁ ... during the use of the use, to determine whether, intercom 3 ₁ ... call line if the intercom 3 ₁ ... in use of 4 is released, the general single telephone T which is connected if not in use.
Of the idle state. Further, when a dial operation is performed from hook-off to hook-on and a dial pulse P is detected as shown in FIG.
Detects the dial data shown in FIG. 10 (c) from the dial pulse P, and performs processes such as a hold process and a door phone call based on the dial data. That is, as shown in FIG. 8, it is determined whether or not the outgoing call is to the outside line 2 based on the dial data. If the outgoing call to the outside line 2 is being made, the dialing operation is performed as it is. It is determined whether the processing, the hold release, or the intercom call is made. No.
FIG. 10 (b) shows a detection period from hook-off to hook-on.

More specifically, the control circuit 11 counts the time interval between the first dial operation and the second dial operation. If the second dial operation is not performed within a predetermined time, it is determined that the call is not an outside line, and based on the dial data. It does the processing. In this embodiment, the dials from "1" to "5" correspond one-to-one to the telephone outlets 10 ₁ ... Of the internal lines connected to the main device 1, and the dial "7" is a door phone call. Is assigned such that the dial "0" while the hold circuit 8 is detecting a busy call is on hold, and the held dial "0" is released such that hold is released, and the control circuit 11 inputs according to this assignment. It does the processing.

When the incoming call detector 7 detects an incoming signal that sounds for one second in three seconds from the central office without dial input, the control circuit 11 performs an incoming call process. This incoming call processing is shown in FIG.
Set the incoming call flag as shown in. That is, FIG. 11 (a)
As shown in FIG. 11, an incoming flag is set as shown in FIG. 11 (b) at the rising edge of the first incoming call detection signal of the incoming call detecting section 7, and after a certain time off delay time has passed since the last falling edge of the incoming call detection signal. After that, the flag is reset.

Such incoming detection determines the presence of the call from the doorphone 3 ₁ ... if not, if there is the intercom 3 ₁ ... call from, so make the intercom call flag as shown in FIG. 11 (b) is there. That is, as shown in FIG. 12 (a), when the push button of the intercoms 3 ₁ ... Is operated and the call signal is detected by the call signal detecting sections 14 ₁ . As shown in FIG. 12 (b), the intercom call flag is set at the rise of the detection signal. Thereafter, when the hook-off of the connected general telephone T is detected as shown in FIG. 12 (c), the flag is set. Reset it. And if this hook-off detection does not exceed a certain timeout period,
Reset the flag again. Thus, the input processing is performed as shown in FIG.

Now, on the other hand, the output process is a connection process as shown in FIG.
There is a call displaying process, connection processing to determine whether during an outside call as shown in FIG. 14, the connection unless an external call in external changeover relay Ry ₁₁ ... of switching contact 20 ₁ ... to a contact side and disconnect the extension 5 than external 2, if external call in connected external changeover relay Ry ₁₁ ... of switching contact 20 ₁ ... to the contact b side, connects the outside line 2 and the extension 5.

It is further determined whether or not an extension call is in progress. If the extension call is not in progress, the relay contacts 18 ₁₁ , 18 ₁₂ ... of the extension connection relays Ry ₄₁₁ , Ry ₄₁₂ ... are turned off, and if the call is in progress, the main device is turned on. 1 can be connected to the extension 5. Next, it is further determined whether or not a call is being made with the intercom 3 ₁ …
If the call is not in progress, the relay contact 17 of the intercom connection relay Ry ₃ is turned off. If the call is in progress, the relay contact 17 is turned on, and the output of the intercom circuit 13 can be connected to the internal circuit and the extension 2.

Next, if a door phone call is in progress, the door phone during the call is the first
Determining whether intercom 3 _1, connecting the first intercom 3 ₁ a long if intercom changeover relay Ry _second switching contact 16 to the contact b side, the a-contact side when the second intercom 3 ₂ side .
Then, it is next determined whether or not the call is being held with the outside line 2 and the call is on hold. If the call is on hold, the hold circuit 8 is turned on, and if not, the hold circuit 8 is turned off.

In the incoming call display control, as shown in FIG. 15, when an incoming signal from the outside line 2 is detected, the control circuit 12 sets an outside line incoming notification sound, and the relay contacts 25 of the extension calling relays Ry ₆₁ .
₁ ... off and turn on the relay contact 21 ₁ of the extension connection relay Ry _51. If there is no detection of the incoming signal intercom 3 ₁ ... to determine whether or not there is a detection of the call signal, if there is a detection performs a door intercom 3 ₁ ... incoming call alert sound set of the extension call relay Ry ₆₁ ... relay contacts 25 ₁ ... turned on, turn off the extension connection relay Ry _51, relay contact 21 ₁ of Ry _52, 21 _2. If there is no detection, determine whether there is an extension call,
When an extension call is detected, an extension ring tone is set, the relay corresponding to the extension on the called side of the extension call relay Ry ₆₁ is operated, and its relay contacts 25 ₁ ...
And turn on the relay contacts 21 ₁ and 2 of the extension connection relays Ry ₅₁ and Ry ₅₂
Turn off 1 and ₂ . If no extension is detected, it is detected whether the call is on hold. If the call is on hold, a hold alarm is set, the relay contact 25 _{1 of the} extension call relay Ry ₆₁ is turned on, and the extension connection relay Ry ₅₁ , Ry ₅₂ relay contacts 21 ₁ , 21 ₂
Off. The relay contact 21 ₁ of the extension call relay Ry ₆₁ ... relay contact 25 ₁ of ... and extension connection relay Ry _51, Ry ₅₂ performs silence set to be pending, 21 ₂ is turned off.

As described above, in the incoming call control processing routine, the state is determined, and the control circuit 11 sets the mode of the notification sound from the sound source generation unit 23,
The notification sound of the connected general single telephone T is set.

Thus, when an incoming signal is received from the outside line 2, the control circuit 11 determines an incoming call based on the incoming call detection signal from the incoming call detection section 7, performs an incoming call notification sound set, and outputs an extension calling relay Ry.
₆₁ ... relay contacts 25 ₁ ... off of, extension connection relay Ry _51,
Relay contact 21 of Ry _{52 1,} 21 ₂ to turn on. Since this time external changeover relay Ry ₁₁ ... is connected 20 ₁ ... the switching contact on the contact b side, ringing from the telephone stations are broadcast from the general single line telephone T connected to the telephone outlet 10 ₁ ... Will be.

Here, when the handset of the general single telephone set T is lifted up and hooked off, the hookoff is detected by the hook / dial pulse detecting unit 30, and the control circuit 11 enters a communication state with the outside line 2 based on this detection. Is determined. In this state, when the handset of the general single telephone set T connected to the telephone outlet 10 ₁ ... Which is in a non-communication state with respect to the outside line 2 is picked up, the hook dial pulse detecting unit 30 detects this hook-off and allows the extension telephone. the extension connection relay Ry ₄₁₂ ... relay contact 18 ₁₂ with switches external changeover relay Ry ₁₁ ... of switching contact 20 ₁ ... to extension side of a contact point if a state corresponding to the telephone outlet, ... is turned on, the sound source in external call such as "Puppuppu ..." from the generator 23, a sound source signal indicating the extension available condition, the relay contact 21 ₁ of another extension connected relay Ry _51, the relay contact 18 ₁₂ ... and, Through the switching contacts 20 ₁ … to the extension 5 corresponding to the telephone outlet,
The tone is emitted from the receiver of the connected general single telephone set T.

Next, the push button of the door phone 3 ₁ … is operated, and the door phone is operated.
When there is a call from 3 ₁ ..., This call signal is detected by the corresponding call signal detecting section 14 ₁ ..., And the control circuit 11 determines that there is a call from the intercom 3 ₁ . The determination by the control circuit 11 is equipped intercom 3 ₁ was performed and invokes the intercom changeover relay Ry ₂ of switching contact 16 turns on the relay contact 17 of the intercom call connection relay Ry ₃ ...
Switch to the side. The extension connection relay Ry ₄₁₁ ... turns on the relay contact 18 ₁₁ ... of, as well as can be connected to the intercom call circuit 13 to an extension 5, to turn on the relay contacts 21 ₂ of the internal connection relay Ry _52. Further, the relay contacts 25 _{1 of the} extension call relays Ry ₆₁ are turned on, and the output of the telephone outlet I / F amplifier 24 is connected to the control line 6. In addition, a door phone in which the type of the sound source signal output from the sound source generation unit 23 is called and operated.
The control circuit 11 controls the sound source generation unit 23 so that the signal having a corresponding tone color, melody, or the like assigned to identify 3 ₁ ...

Thus, a notification sound indicating that there is an incoming call from the door phone 3 ₁ ... Is emitted from the speaker 48 of each telephone outlet 10 ₁ . , On the other hand, the intercom 3 ₁
On the... Side, the corresponding back tone transmitting section 15 is turned on by the control circuit 11, the sound source signal from the sound source generating section 23 is input as a back tone, and is emitted from the speaker (not shown) of the intercom 3 ₁ . Will be.

When the incoming call of the intercom 3 ₁ is notified and the handset of the general single telephone T connected to any of the telephone outlets 10 ₁ is picked up, the telephone to which the first general single telephone T is connected is connected. Outlet 10
_The switching contacts 20 ₁ ... Of the external line switching relays Ry ₁₁ corresponding to ₁ ... Are switched to the a contact side under the control of the control circuit 11, and are connected to the doorphone via the extension 5. At the same time, the sound source generator 23 is set to a silent state. If, for example, 30 seconds elapse after the calling operation is performed and there is no hook-off of any of the telephones T, the notification indicating the incoming call is automatically stopped.

Thereafter, when the handset of the general single telephone set T connected to another telephone outlet is picked up, if the other telephone set T is engaged in an outside line call, an external line connection relay Ry ₁₁ .
Is switched to the extension side, and at the same time the corresponding extension connection relay
The relay contacts 18 _{12 of} Ry ₄₁₂ are turned on, and the output of the sound source generator 23 is connected, but no sound can be heard from the receiver because of the silent state. That is, it is understood that the outside line is being used.
Under the control of the external switch relay Ry ₁₁ ... control circuit 11 corresponding the telephone T that took up the handset if during this external use in which telephone receptacle 10 ₁ ... which connect, switching contact to the outside line 2 side 20 ₁ .. Are connected, an outside line dial tone is heard from the handset, and it is known that the outside line is usable.

When the call ends and the handset of the telephone set T is hooked on, the state returns to the state before the call under the control of the control circuit 11.

Although the case of the above has been described assuming a call from the doorphone 3 ₁ ..., once after completion of the call, when to call the doorphone 3 ₁ ... from the telephone T side, picks up the handset of the telephone T, dialing To send a predetermined number, that is, the number assigned to the door phone call, for example, “7”. That is, based on the dial data, the control circuit 11 connects the telephone T to the telephone outlet.
10 ₁ … is connected to the door phone communication circuit 13, the switching contact 16 of the door phone switching relay Ry ₂ is connected to the door phone on which the last call operation was performed, and a state in which communication with the door phone is possible is set. Will be able to talk to you.

Next, when making a call between extensions, the handset of the telephone set T is picked up and the extension number of the other party may be dialed. When the outside line 2 is open, the control circuit 11 picks up the handset, and if only the dial data of the extension call is detected within a predetermined time, determines that the call is an extension call, and determines that the call is an extension call.
The switching contacts 20 ₁ … of the external line switching relay Ry ₁₁ … corresponding to 10 ₁ …
Are connected to the a contact side of the extension line, and at the same time, the relay contacts 18 ₁₂ ... Of the corresponding extension connection relays Ry ₄₁₂ . The extension calls the relay Ry ₆₁ ... control circuit 11 of the relay contact 25 ₁ of which corresponds to the telephone outlet 10 ₁ ... the called side is turned, also sets the sound signal of the sound source generating unit 23 of the type of the extension call. Accordingly, the sound source signal amplified by the telephone outlet I / F amplification unit 24 drives the speaker 48 of the called telephone outlet 10 ₁ ... To notify the extension call with a sound such as “boo-boo”. Control circuit 11 and the notification has passed a predetermined time stops the operation of the sound source generating unit 23 turns on the relay contact 21 _{and second} extension connection relay Ry _52,
The extension 5 of the called telephone T is connected to the outlet I / F amplifying unit 24, and the voice signal of the called telephone T is transmitted to the control line 6.
Superimposed on the lines L ₃ and L ₄ of the telephone line and sent to the telephone outlets 10 ₁ . Therefore, the voice signal from the calling side is reproduced by the speaker 48 of the telephone outlets 10 ₁ ... Of the called side, and the message can be unilaterally transmitted from the calling side to the called side. In other words, even if the called general telephone T is busy,
The message can be transmitted whether the handset is picked up or not.

When the handset of the telephone set T connected to the telephone outlet 10 ₁ … of the called extension number is hooked off, the control circuit 11 switches the switching contacts 20 ₁ … of the external line switching relays Ry ₁₁ … of the telephone outlet 10 ₁ …. The relay contacts 18 ₁₂ ... Of the corresponding extension connection relays Ry ₄₁₂ are turned on at the same time, and the telephones T of the calling side and the called side are connected to each other through the extension 5. At the same time, the relay contacts 25 _{1 of the} extension calling relays Ry ₆₁ are turned off, and the relay contacts 21 ₂ of the extension connecting relay Ry ₅₂ are turned off. The set sound source signal of the sound source generating unit 23 to the sound source signal in the internal call, connects its output to the connection state via the relay contacts 21 ₁ of the extension connection relay Ry ₅₁ to extension 5. If the telephone set is not busy with the outside line 2 and the handset is off-hook by another telephone set T while the extension lines 5 are talking with each other, the control circuit 11 causes the outside line relays Ry ₁₁ ... Corresponding to the telephone outlets 10 ₁ .
So that the external line dial tone from the handset of the telephone T the switching contact 20 ₁ ... a from an outside line 2 side. When the outside line 2 is busy, the control circuit 11 connects the switching contacts 20 ₁ ... Of the outside line relays Ry ₁₁ ... Corresponding to the telephone outlets 10 ₁ . Since the relay contacts 18 _{11 of} Ry ₄₁₁ are turned on, the handset of the telephone set T can hear the sound generated by the sound source signal output from the sound source generation unit 23 while using the extension.

When calling an outside line while the outside line is not used, the handset of the telephone set T connected to _one of the telephone outlets 10 ₁ ... May be picked up and dialed. First, the control circuit 11 and off-hook is detected connects the outside line changeover relay Ry ₁₁ ... of switching contact 20 ₁ to an outside line 2 side, further dialing operation is performed, the hook dialing pulse first dial data to control circuit 11 after entering the detector 30 _1, a predetermined time as shown in Figure No. 16 (b), the control circuit 11 as an extension or intercom call if there is no input of the next dial data within for example 3 seconds determines Is as described above, but as shown in FIG.
When the next dial data is input within an interval of less than one second, the control circuit 11 determines that an outside line has been called, and holds the connection state between the outside line 2 and the telephone set T without switching the extension side.

By the way, if it is desired to hold the connection while the connection to the outside line 2 is established, the holding circuit 8 may be operated.

Next, the operation of the hold circuit 8 will be described. First, the handset of the telephone T is picked up when calling the outside line _2, and when a dial operation is performed as shown in FIG.
Current flows through the light emitting diodes LED ₁ photocouplers PH ₁ which is provided in the hook dial examined portion 30 inserted into, current corresponding to the dial pulses, as shown in FIG. 18 (a). Current does not flow as FIG. 18 in the light-emitting diode LED ₂ of photocoupler PH ₂ at this time is inserted into the other line L ₁ (b). Therefore, the control circuit 11 to which the outputs of both the photocouplers PH ₁ and PH ₂ are input determines that it is at the time of calling. When the handset of the called telephone is picked up, and reversed polarity external 2, line L ₁ is H, linear L ₂ is L, a current flows through the light emitting diode LED ₂ of the photocoupler PH _2, the other photo-coupler No current flows through the light emitting diode LED ₁ of PH ₁ . That is, it indicates that the telephone is in a call state.

At the time of an incoming call from the outside line 2, the light emitting diodes LED ₁ and L ₁ are alternately turned on and off as shown in FIGS.
Current flows through the ED _2. At this time, the incoming signal transmits a 16 Hz signal for 1 second, and repeats a pause for 2 seconds, so that a pulse current flows through the alternate light emitting diodes LED ₁ and LED ₂ for _{1 second,} and then the current of both the light emitting diodes LED ₁ and LED ₂ flows for 2 seconds. Does not flow.
And after this state is repeated, the handset of the telephone T is taken up, at which point the line L ₂ H, line L ₁ is L, the light emitting diode current flows through the LED _1, the light emitting diode LED ₂ current Stops flowing. That is, it indicates that the telephone is in a call state.

Here, the control circuit 11 determines whether or not a call is being made in both the case of calling and the case of receiving a call.
Figure photocoupler as shown in (b) PH ₁ or photocoupler PH ₂
The control circuit 11 sets a flag when the output of the control circuit 11 becomes H for 5 msec or more. The lifetime of this flag is set to 3 seconds, H becomes as shown on the reverse output of the photocoupler PH ₁ or PH ₂ of its upright flag within 3 seconds Figure 20 (b) or FIG. 21 (a) If the state continues for one second, the control circuit 11 determines that a call is in progress as shown in FIG. 20 (c) or FIG. 21 (c). In addition, since the judgment is made as shown in FIG. 20 and FIG. 21, even if the lines L ₁ and L _{2 of the} outside line ₂ are reversely connected, the call judgment can be made.

When a call is put on hold in a state where it is determined that a call is in progress (shown in FIG. 22 (a)), first, the number assigned to the call by dialing the telephone T, for example, "0"
Outgoing. When this dial operation is performed, the line L ₂
During the dial pulse, the voltage level becomes L as shown in FIG. 22 (b), and the hook / dial pulse detectors 30 ₁ .
Detected by the photocoupler PH _1, and inputs to the control circuit 11 as the dial data. Control circuit 11 which has received the dial data is judged to hold operation, to turn on the transistor Q _1, to drive the relay Ry _7, turn on the relay contact 55,
The resistance R is connected to the lines L ₁ and L ₂ to be in a hold state. When the telephone T is disconnected from the telephone outlets 10 ₁ … in this hold state,
The output of the photocoupler PH ₁ becomes the L. The output of the photocoupler PH ₁ is H again to connect the telephone T. So for Resume, through hook dialing detector 30 ₁ ... perform dial operation, given a dial data "0" to the control circuit 11, control circuit 11 determines that hold release, turns off the transistors Q ₁ Then, the relay Ry ₇ is returned, the relay contact 55 is turned off, and the resistor R is disconnected from the line L ₁ , L ₂ . At this time, since the telephone T has already captured the outside line 2, the telephone conversation can be continued. The Figure 22 (c) is the output of the photocoupler PH _2, also FIG. (D) of indicating the hold.

When the hold is set, a hold sound is emitted from the hold sound generation unit 29 and sent to the telephone of the other party through the outside line 2.

When a call is made from the intercom 3 ₁ ... During an outside call, when a dial number corresponding to the intercom 3 ₁ ... The control circuit 11 operates the hold circuit 8 according to the dial data from the detection units 30 ₁ .
While on hold connecting the telephone T as with the intercom call described above to intercom 3 ₁ ....

Therefore, the dial operation only needs to be performed once for the doorphone connection.

According to the present invention, in a telephone system, means for superposing a voice signal from an extension of a calling side on a control line of a called side at the time of an internal call is provided in a main device, and each telephone outlet is provided with the control line of the control line. Since the speaker for reproducing the superimposed voice signal is provided, the voice signal from the calling telephone that has called the extension from the telephone outlet can be reproduced on the speaker of the telephone outlet.
The message can be transmitted in one direction irrespective of the state of the telephone on the called side, which is very effective in an emergency or the like.

[Brief description of the drawings]

FIG. 1 is an overall circuit configuration diagram of Embodiment 1 of the present invention, FIG. 2 is a circuit configuration diagram of a main unit of the above, FIG. 3 is a circuit configuration diagram of a telephone outlet of the same embodiment, and FIGS. FIGS. 10 and 11 are flow charts for explaining the operation of the above, FIGS. 13 to 15 are flowcharts for explaining the operation of the above, and FIGS. Fig. 17 is a time chart for explaining the operation of the above-mentioned reserve circuit, Fig. 17 is a circuit configuration diagram of the same reserve circuit, and Figs. 18 to 22 are time charts for explaining the operation of the same reserve circuit. T: General single telephone, 1 ... Main unit, 2 ... Outside line, 4
…… Talk line, 5… Extension, 10 ₁ …… Phone outlet, 45
... modular jacks, 48 ... speakers.

Continued on the front page (72) Inventor Hitoshi Fukakawa 1048 Kadoma Kadoma, Matsushita Electric Works Co., Ltd. (72) Inventor Yoshiharu Suzuki 1048 Kadoma Kadoma, Kadoma City Matsushita Electric Works Co., Ltd. (72) Miyuki Kadota, Inventor 1048 Oji Kadoma Matsushita Electric Works Co., Ltd. (72) Inventor Kiyotaka Takehara 1048 Oji Kadoma Kadoma City Matsushita Electric Works Co., Ltd. (56) References JP-A-61-219251 (JP, A) JP-A-57-186864 ( JP, A) JP-A-52-120706 (JP, A) JP-B-56-41025 (JP, B2)

Claims (2)

(57) [Claims] 1. An external line and a plurality of extensions from a telephone station are star-connected, and when an incoming signal is detected from the external line, control means for transmitting an incoming display signal via a control line corresponding to each extension is provided. Means for determining whether an external call or an internal call is to be made by dialing from the apparatus, and when the means judges that the call is an internal call, a call signal is sent out via a control line of the called party corresponding to the dialed number, and A main unit having a means for connecting the extension on the calling side and connecting the external line to a predetermined extension during an external call, a telephone connection unit connected to each of the above-mentioned extensions, and an incoming call from the main unit connected to the control line. A telephone outlet provided with incoming call display means for receiving a display signal and displaying an incoming call, and calling means for receiving a call signal for an extension and performing a call display; And a telephone system detachably connected to the telephone connection portion of the telephone system, wherein the main device is provided with means for superimposing a voice signal from the extension of the calling side on the control line of the called side during internal calling. A telephone system, wherein each telephone outlet is provided with a speaker for reproducing an audio signal on which the control line is superimposed. 2. The telephone system according to claim 1, wherein said speaker is also used for notifying a call signal.