JP2637086B2 - Telephone system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 【Technical field】

The present invention relates to a telephone system in which a call position can be selected by connecting an insertion plug of a telephone to one of a plurality of telephone outlets.

[Background Art]

Conventionally, this type of telephone system has a
A plurality of telephone outlets 10 in which the telephone line 2 'is commonly wired
By connecting the insertion plug 60 of the telephone set T to any one of ₁ '..., the call position can be freely selected. By the way, in such a conventional example, there is a problem that it is not possible to change the telephone position by changing the telephone outlet 10 ₁ ′ to which the telephone is connected during the telephone call. That is, during a call, the plug of the telephone T
'Changing the talking position plugged into the attachment plug 60 one telephone outlet 10 _1' 60 is withdrawn from one of the telephone receptacle 10 ₁ other telephone outlet 10 ₂ are opened telephone line 2 'at the time of pulling the In the telephone exchange of the central office, this telephone line 2 '
Since the end of the call is determined by opening the telephone, there is a problem that the telephone cannot be moved during the call.

[Object of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a telephone system in which a telephone can be easily moved even during a call.

DISCLOSURE OF THE INVENTION

Hereinafter, the present invention will be described with reference to examples. Embodiment FIG. 1 shows an overall configuration of an embodiment of a telephone system. This embodiment enables an extension call, and a main unit 1 has an external line 2 as an external telephone line from a telephone station. And the communication line 4 to which the door phone 3 is connected as an external line, and further, an extension 5 as an internal telephone line and a control line 6
Are connected to each other. Each of the internal lines is connected to a telephone outlet 10 ₁ ... To which a general single telephone T as a load device is connected. 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, each connected to the terminal 12 ₁ ... respectively intercom 3 ₁ ... of the call signal detector 14 ₁ ... and back connect the tone sending portion 15 ₁ ... and through the intercom changeover relay Ry ₂ of switching contact 16 is connected to the intercom call circuit 13.
The door phone communication circuit 13 includes a relay contact 17 of the door phone communication connection relay Ry ₃ and a relay contact 18 of each extension connection relay Ry ₄₁₁ , Ry ₄₁₂ … provided corresponding to each telephone outlet 10 ₁ .
_11, 18 is connected ₁₂ ... and through a capacitor 19 ₁ ... DC blocking to each external line changeover 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 amplifying unit 24 is supplied to each telephone outlet 10 ₁ via the DC cut capacitor 26 and the relay contact 25 _{1 of the} extension calling relay Ry6 ₁ … provided corresponding to each telephone outlet 10 ₁ …. ... it is connected to the termination connection terminal corresponding to the line L ₃ of the control lines 6. The output of the line L ₃ of the control line 6 via the coil 27 ₁ ... interrupting source signal telephone outlet I / F display drive section 28 is connected. 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 ... Are plug-in outlets 60 of the telephone set T connected to the lines L ₁ and L ₂ of the extension 5 as shown in FIG.
And a line L ₃ , L of the control line 6
Is connected between the _4, the voltage level detection circuit 46a, 46b and the line L _3, L capacitor 47 is connected between ₄ and speaker 48 and the slide-type volume control volume of which is turned in accordance with the DC voltage between line 49 and a voltage level detection circuit 46a, 46b
It includes respectively corresponding line L ₃ and the voltage level detection circuit 46a, coupled LEDs LEDa for outside line busy display between 46b, the light-emitting diode LEDb for in extension talking displayed. The voltage level detection circuits 46a and 46b are turned on in response to a voltage signal from the main device 1, and can be displayed by light emission of the red light emitting diode LEDa and the green light emitting diode LEDb according to the outside line and the inside line in use. Has become. The loudspeaker 48 constitutes an incoming call display means. The loudspeaker 48 audibly responds to a sound source signal transmitted from the main apparatus 1 while being superimposed on the lines L ₃ and L ₄ , and notifies the incoming call from the intercom 3 ₁ and the call of the extension 5. You can do it. 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, busy 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, the process of the outside line 2 busy if the incoming call, if not the incoming call to determine if the door phone 3 ₁ ... during call, in the calling If there is, the processing during the call with the intercom 3 ₁ ...
It is determined whether or not a call is being made between each other.
If the call is not being further processed, the outside line 2
It is determined whether or not it is usable. If the outside line 2 is usable, the process during the call of the outside line 2 is performed, and if the outside line 2 is not usable, the process during the call between the extension lines 2 is performed. Therefore, if there is no extension 5 call, external line incoming call or intercom call, the extension 5 connected to the telephone set T is connected to the external 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. When a dial operation is performed between hook-off and hook-on and a dial pulse P is detected as shown in FIG.
Detects the dial data shown in FIG. 7 (c) from the dial pulse P, and performs a process 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 call is to the outside line 2 based on the dial data. If the call to the outside line 2 is being made, the dial call is performed as it is. Only processing, hold release, or door phone call is determined. Seventh
FIG. 7B 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 the present embodiment, the dials from "1" to "5" correspond to the telephone outlets 10 ₁ ... Of each internal line connected to the main unit 1 on a one-to-one basis, 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 a call from the doorphone 3 ₁ ..., so make the intercom call flag as shown in FIG. 9 (b) is there. That is, as shown in FIG. 12 (a), when the push button of the doorphones 3 ₁ ... Is operated and the calling signal is detected by the calling signal detectors 14 ₁ .
The control circuit 11 sets the intercom ringing flag at the rise of the detection signal, and then resets the flag when the hook-off of the connected general single telephone T is detected as shown in FIG. 12 (c). . If the hook-off detection does not exceed a predetermined time-out period, the flag is also reset. 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 are incoming call display processing and busy display processing.
As shown in FIG. 14, it is determined whether or not an external line call is in progress. If no external line call is in progress, the switching contacts 20 _{1 of the} external line switching relays Ry ₁₁ .
Detaching the extension 5 than external 2 connected to a contact side, external switch relay if external call in Ry ₁₁ ... of switching contact 20 ₁
Are connected to the contact b side, and the external line 2 and the internal line 5 are connected. 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 _{1 of the} extension calling relays Ry ₆₁ .
Off and turn on the relay contact 21 ₁ of the extension connection relay Ry _51. If the incoming signal is not detected, it is determined whether or not the calling signal of the intercom 3 ₁ … is detected. If the intercom signal is detected, the incoming call sound of the intercom 3 ₁ … is set, and the extension calling relay Ry is performed.
Turn on relay contacts 25a… of a ₅ … and connect the extension connection relays Ry ₅₁ ,
Turn off the relay contacts 25 ₁ and 25 ₂ of Ry ₅₂ . If there is no detection, it is determined whether there is an extension call. If an extension call is detected, an extension ring tone is set and the extension call relay is set.
The relay corresponding to the extension on the called side of Ry ₆₁ … is operated, and its relay contacts 25 ₁ … are turned on, and the extension connection relay R
y _51, the relay contact 21 ₁ of Ry _52, 21 ₂ to turn off. If no call is detected for the extension, it is detected whether the call is on hold. If the call is on hold, a hold sound is set, and the extension call relay Ry ₆₁ …
Turn on the relay contacts 25 ₁ … of the internal connection relays Ry ₅₁ , Ry ₅₂
The relay contacts 25 ₁ and 25 ₂ are turned off. The extension call relay Ry ₆₁ ... relay contact 25 ₁ of the performed silence set to be pending ... and the relay contact 25 ₁ of the extension connection relay Ry _51, Ry _52,
Turn off 25 ₂ . 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. Next, in the busy display process, as shown in FIG. 15, it is determined whether or not the outside line 2 is busy, and if it is busy, the light emitting diode LEDa corresponding to the outside line is lit. Also determine whether the pending if not busy, turns on the light emitting diode LEDa if pending, turns off the light emitting diodes LEDa if not pending, also whether it is busy doorphone 3 ₁ ... and If the doorphones 3 ₁ … are busy, the corresponding LED is turned on during the extension call, and if not busy, it is determined whether the extensions are busy. If the line is busy, the light emitting diode LEDb is turned on, and if neither extension is busy, the light emitting diode LEDb is turned off. Thus, in the busy display processing, the light emitting diodes LEDa and LED
The lighting and turning off of b is controlled according to the state. 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 makes an extension call relay Ry ₆₁ .
Off the relay contacts 25 ₁ … of the internal connection relays Ry ₅₁ , Ry ₅₂
Relay contacts 25 ₁ and 25 ₂ are turned on. At this time, since the outside line switching relays Ry ₁₁ have the switching contacts 20 ₁ ... Connected to the b-contact side, the ringing tone from the central office is transmitted to each telephone outlet 10 ₁ .
Is notified from the general single telephone set T connected to. At the same time, when the reception of the incoming signal is detected, a voltage level detection circuit 46a that controls the light emitting diode LEDa by using the DC output voltage from the telephone outlet I / F display drive unit 28 to indicate that an outside line is busy, together with the above-mentioned call. Is controlled so as to be the detection voltage. Therefore, the voltage level detection circuits 46a of the telephone outlets 10 ₁ ... Turn on to turn on the light-emitting diodes LEDa, thereby indicating that an outside line is busy. 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 ..., The 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 switches the intercom 3 ₁ ... side performing the call intercom call connection relay Ry ₃ of switching contact 16 of the relay contact 17 is turned on and the door phone switch relay Ry _2. Also, the relay contacts 18 _{11 of the} extension connection relays Ry ₄₁₁ are turned on to enable the door phone communication circuit 13 to be connected to the extension 5 and the relay contacts 21 ₁₂ of the internal connection relay Ry ₅₂ are turned on. Furthermore, the relay contact 25 _{1 of the} extension calling relay Ry ₆₁ …
... is turned on, and the telephone outlet I / F amplifier 24 is connected to the control line 6.
Connect the output of Further, the control circuit 11 is a telephone outlet.
The voltage level of the output voltage signal of the I / F display drive unit 28 is set to a voltage level at which the voltage level detection circuit 46b corresponding to the extension busy display light emitting diode LEDb is turned on.
Further, the control circuit 11 controls the sound source generation unit so that the type of the output sound source signal of the sound source generation unit 23 becomes a signal having a corresponding timbre or a melody that is assigned so that the intercom 3 ₁ ... Control 23. 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 . become. The corresponding back tone transmitting unit 15 is turned on by the control circuit 11 on the side of the intercom 3 _1, which has performed the one-way calling operation, and the sound source signal from the sound source generating unit 23 is input as the back tone, and the speaker of the intercom 3 ₁ . (Not shown). 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. Note that if there is no hook-off of any of the telephones T, for example, 30 seconds after the calling operation is performed, the notification as the incoming call display and the display by the light emitting diode LEDb are 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.
While the external line is being used, it is displayed even when the light emitting diode LEDa is turned on. If the outside line is not in use, the telephone outlet 10 ₁ to which the telephone set T picking up the handset is connected is connected.
Under the control of the external switch relay Ry ₁₁ ... control circuit 11 corresponding to, hear external dial tone from the handset for connecting 20 ₁ ... the switching contact on the outside line 2 side, it is found outside line usable state . Of course, in this case, the light emitting diode LEDa is turned off, and it can be seen from the display state that the outside line can be used. 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. After While in the case of the above has been described assuming a call from the intercom 3 ₁ ..., which temporarily end the call, if the telephone side door phone 3 ₁ ... calling the picks up the handset of the telephone T, performing dial operation A predetermined number, that is, a number assigned to the intercom call, for example, “7” may be sent. That is, based on the dial data, the control circuit 11 connects the telephone outlets 10 ₁ ... To which the telephone T is connected to the door phone communication circuit 13, and the switching operation of the switching contact 16 of the door phone switching relay Ry ₂ is performed last. The user can then connect to the intercom and set a state in which a call can be made with the intercom, and can make a call with the intercom again. 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 telephone is connected to the telephone set T. 10 ₁ …
Corresponding external changeover relay Ry ₁₁ ... of switching contact 20 ₁ ... was connected to a contact side of the extension side, and on the relay contacts 18 ₁₂ ... the extension connection relay Ry ₄₁₂ corresponding simultaneously. The extension call 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 extension calls. Therefore, the sound source signal amplified by the telephone outlet I / F amplifying unit 24 drives the speaker 48 of the called telephone outlet 10 ₁ ... At the same time, the control circuit 11 is connected to the telephone outlet I / F drive 2
8 and output DC voltage to each voltage level detection circuit 4.
Set the level to turn on 6b, each phone outlet 10 ₁
.. Are turned on by the light-emitting diodes LEDb for the display during the extension. When the handset of the telephone set T connected to the telephone outlets 10 ₁ ... of the called extension numbers is hooked off,
The control circuit 11 connects the switching contacts 20 ₁ of the external line switching relays Ry ₁₁ of the telephone outlets 10 _{1 to} the a contact side of the extension, and at the same time, the relay contact 1 of the corresponding extension connection relay Ry ₄₁₂
8 ₁₂ ... Are turned on, 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, extension call relay Ry ₆₁
The relay contacts 25 _{1 of} … 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 a connectable state to the extension 5 through the relay contacts 21 ₁₁ of the extension connection relay Ry _51. If the telephone set T is not busy with the outside line 2 and another telephone set T is handset while the extension lines 5 are talking with each other, the control circuit 11 switches the switching contacts of the outside line relays Ry ₁₁ corresponding to the telephone outlets 10 ₁ . since connecting 20 ₁ ... the external line 2 side so that the outside line dial tone from the handset of the telephone T. 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, FIG. 17 (b) for a predetermined time as shown, extension or intercom and control circuit 11 is a call to without input of the next dial data for example, within 3 seconds determines As described above, when the next dial data is input within an interval of 3 seconds or less as shown in FIG. 17 (a), the control circuit 11 determines that an outside line is to be called, and does not switch the extension side to the outside line 2 without switching. The connection state with the telephone set T is maintained. At this time, at the same time when the hook-off is detected, the voltage level of the output voltage signal of the telephone outlet I / F display drive unit 28 is detected by a voltage level detection circuit.
The control circuit 11 sets the level at which 46a is turned on, and turns on the light emitting diode LEDa of each telephone outlet 10 ₁ …
Indicates that an outside line is busy. 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, when calling outside line 2, the handset of telephone T is picked up.
As shown in FIG. 18, when a dial operation is performed, a current flows through the light emitting diode LED ₁ of the photocoupler PH ₁ which is a current / voltage conversion element provided in the hook / dial detecting unit 30 inserted into the line L ₂ , As shown in FIG. 3A, a current flows according to the dial pulse. Current does not flow as Figure 19 the light emitting diode LED ₂ of photocoupler PH ₂ at this time is inserted into the other line L ₁ (b). Therefore, both photocouplers PH
_1, the control circuit 11 which receives the output of the PH ₂ determines that when called. When the handset of the called telephone is picked up, and reversed polarity external 2, line L ₁ is H, linear
L ₂ becomes L, current flows through the light emitting diode LED ₂ of the photocoupler PH ₂ , and the light emitting diode LED of the other photo coupler PH _1
No current flows in 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 according to the incoming signal 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 alternately for the light emitting diodes LED ₁ and LED ₂ for 1 second, and then for 2 seconds both light emitting diodes LED ₁ and LED _{2 have a} current. 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 21 (b) or Figure 22 (a) If the state continues for one second, the control circuit 11 determines that a call is in progress as shown in FIG. 21 (c) or FIG. 22 (c). In addition, since the judgment is made as shown in FIGS. 21 and 22, the call judgment can be made even when the lines L ₁ and L _{2 of the} outside line ₂ are reversely connected. When a call is put on hold in the state where it is determined that a call is in progress (shown in FIG. 23 (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
23 becomes L as shown in FIG. 23 (b) during the dial pulse, 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 23 (c) is the output of the photocoupler PH _2, also FIG. (D) of indicating the hold. As described above, in the system according to the present invention, a hold operation is performed by receiving a hold dial pulse only during a call, so that a malfunction does not occur in a normal call. Further, since the hooking determination condition is 100 msec or more in a normal exchange, the exchange does not erroneously determine hooking during a call and a dial pulse for holding. Needless to say, the dial number for holding is not limited to the above embodiment. 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. At this time, a light emitting diode LEDa that indicates that the outside line is busy
The control circuit 11 controls and sets the level of the output voltage signal of the telephone outlet I / F drive unit 28 so as to blink, and blinks to indicate that it is on hold. If a call is made from the intercom 3 ₁ ... During an outside call, a dial number corresponding to the intercom 3 ₁ ... In response to the dial data from the detecting units 30 ₁ , the control circuit 11 activates the hold circuit 8 to put the telephone in a hold state, and connects the telephone set T to the intercom 3 _{1 in the same} manner as the intercom call. Therefore, the dial operation only needs to be performed once for the doorphone connection. Second Embodiment In the first embodiment, the telephone T is used to hold the telephone. However, as shown in FIG.
₁ ... similarly to provide a hold switch device 61 connected to the extension 5, this hold switch device 61 provided with a telephone outlet 10 ₁ ... similarly to the speaker 62 as shown in FIG. 25, from the speaker 62 When an outside line is received, a ringing tone is emitted and a hold operation switch SW is provided. By operating the hold operation switch SW, the main device 1 is controlled via the control line 6 as shown in FIG. The hold operation signal may be transmitted through the signal transmission unit 64. In this case, the main unit 1 is provided with a signal transmission unit 63 for transmitting and receiving signals as shown in FIG.
Simultaneously activates the hold circuit 8 and simultaneously sends an audio signal indicating that the hold has been made to the outside line 2 from the hold sound generating section 29 'comprising an audio signal circuit, and transmits the hold to the other party. It is. At the same time, a signal indicating the suspension is sent from the signal transmission unit 63 to the suspension switch device 61, and the display element 65 provided on the suspension switch device 61 blinks to indicate that the suspension is being performed. When the telephone T is connected to an appropriate telephone outlet 10 ₁ , that is, the hold operation switch SW is again operated to send a hold operation signal to the main device 1, the hold circuit 8 is operated on the main device 1 side. The connection is controlled so as to release the hold and make a call with the other party possible. FIG. 28 shows a hold switch device 61 used in the case of star wiring as in the case of FIG. 1, and in this case, when the hold operation switch SW is operated, the dial number assigned corresponding to the hold is displayed. A pulse is sent from dial pulse circuit 66 to main unit 1 via extension 5. That is, the operation is the same as that of the ordinary telephone T. In this case, the hold switch device 61 is provided with a call detection circuit 67 for notifying of an incoming call, so that a ringing tone can be emitted at the time of an incoming call, similarly to the telephone T. [Effect of the Invention] The present invention is configured as described above, and by connecting a plug of a telephone to any of a plurality of telephone outlets to which a telephone line is wired, a telephone call position can be freely selected, and a telephone call can be made. Means for determining, a signal for holding and releasing a hold during a call, a current-voltage conversion element for detecting a current flowing through the telephone line in two directions and outputting a voltage, and And a main unit having a holding means for holding the telephone line by short-circuiting the telephone line via a resistor when there is a signal for holding is inserted between the external telephone line and the internal telephone line. The telephone line can be automatically put on hold during the call, so you can remove the plug from the telephone outlet and move the telephone even during a call, and hold or hold only during the call determination Since the cancellation is performed, there is an effect that a malfunction does not occur.

[Brief description of the drawings]

FIG. 1 is an overall circuit configuration diagram of a first embodiment of the present invention, FIG. 2 is a circuit configuration diagram of a main device of the above, FIG. 3 is a circuit configuration diagram of a telephone outlet of the same, FIG. 4 to FIG. Flowchart for explaining the operation of the above, FIGS. 10, 11, and 12 are time charts for explaining the operation of the above, FIGS. 13 to 16 are flowcharts for explaining the operation of the above, and FIG. FIG. 18 is a circuit configuration diagram of the above-described holding circuit, FIGS. 19 to 23 are time charts for explaining the operation of the same holding circuit, and FIG. 24 is an embodiment of the present invention. FIG. 25 is a front view of the holding switch device of the above, FIG. 26 is a circuit diagram of the holding switch device of the above, FIG. 27 is a circuit configuration diagram of a main device used in the same, FIG. Fig. 29 is a circuit diagram of another example of the same hold switch device, and Fig. 29 is a schematic circuit configuration diagram of a conventional example. T: General single telephone, 1 ... Main unit, 2 ... Outside line, 3 ₁
… 5,… extension, 8… reservation circuit, 10 ₁ … phone outlet, 30 ₁ … hook / dial pulse detector, 45
... modular plug, 60 plug-in plug.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyotaka Takehara 1048 Kadoma Kadoma Matsushita Electric Works Co., Ltd. (72) Inventor Hiroaki Takeyama 1048 Kadoma Kadoma Kadoma Matsushita Electric Works Co. (56) References JP JP-A-61-219251 (JP, A) JP-A-56-24855 (JP, A) JP-B-56-41025 (JP, B2)

Claims (4)

(57) [Claims] A telephone call plug is connected to one of a plurality of telephone outlets to which a telephone line is wired so that a telephone call position can be selected and a telephone call is determined. Means for determining a signal for releasing the hold, a current-voltage conversion element for detecting a current flowing through the telephone line in both directions and outputting the voltage as a voltage, and a signal for determining that a call is in progress and for holding. A telephone system comprising a main unit having a holding means for holding a telephone line in a holding state by short-circuiting through a resistor via a resistor between the external telephone line and the internal telephone line. 2. The telephone system according to claim 1, wherein the signal for holding and releasing the holding is a dial pulse of a telephone. 3. A signal for holding and canceling a hold is transmitted to a main unit via a control line by operating a hold switch connected to an internal telephone line and a control line. The telephone system described in the section. 4. A dial switch for holding and releasing a hold by operating a hold switch connected to the internal telephone line and the control line, and transmitting the dial pulse to the main unit via the internal telephone line. 2. The telephone system according to claim 1, wherein: