JPS6248159A - Telephone system - Google Patents

Abstract

PURPOSE:To move a telephone set even during talking state by using a resistor to short-circuit a telephone line and setting the line to the holding state when a telephone set removal detection signal is obtained from a removal detection means and resetting the holding state when a connection detecting signal is obtained from the removal detection means. CONSTITUTION:When a reset signal is inputted to a contact control circuit 8e, a contact S0 is turned OFF to reset the holding state. Further, a signal retarded by a delay circuit 8b from the said reset signal resets an R-S latch circuit 8b to prepare for the next holding state. A resistor R0 is disconnected at a point of time t5 when the holding state T7 to increase a voltage V12 and the voltage V12 is increased more at a point of time t6 when the talking is finished and a handset is hooked on. Since a voltage V34 is unchanged at a point of time of the leading of the voltage, no removal detection signal is outputted from the removal detection means 7, the output of an AND circuit 8a remains at L level and no holding means 8 of a holding control circuit 9 malfunctions at point of times t5 T6. Thus, the telephone set is moved easily even during the talking state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a telephone system in which a telephone call position can be freely selected by connecting a plug of a telephone to any one of a plurality of telephone outlets.

[Background Art] Conventionally, as shown in FIG. 4, in this type of telephone system, the telephone position can be freely selected by connecting the plug 3 of the telephone 2 to any one of a plurality of telephones 1. was. Note that each telephone set 1 has a telephone 2 plugged into it.

10 backup line 0/roux line wiring (
However, in the conventional example shown in FIG. 4, the protection lines , , L are not used. By the way, in such a conventional example, there is a problem that during a call, it is not possible to change the telephone outlet 1 to which the telephone 2 is connected to change the call position. In other words, if you are on a call and change the call position by pulling out the plug 3 of the telephone 2 from one telephone outlet 1 and inserting it into the other telephone outlet 1, the moment you pull out the plug 3 from the other telephone outlet 1, the Telephone line, L
2 will be opened, and the telephone exchange (not shown) will open this telephone 41AL1. Since it is determined that the call is over when L2 is released, the phone f
There was a problem that i2 could not be moved.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide a telephone system in which the telephone can be easily moved even during a call.

[Disclosure of the Invention] (Embodiment 1) Fig. 1 shows an embodiment of the present invention, in which a telephone line,
L2 and protection line L3. Plug the telephone 2 into one of the plurality of telephone outlets 1 to which L is wired.
In a telephone system similar to the conventional example in which the calling position can be freely selected by connecting the above-mentioned telephone outlet 1
The backup ports #iL, , L, wired to the telephone set HA L are used as control lines, and the impedance element 4 connected to the control amount #iL, , L is provided in the plug 3.
+, a voltage change detection means 6 for detecting the rise of the line voltage of L2, and a control port mL3. Telephone 2 depends on whether impedance element 4 is connected between L4 or not.
A rising detection signal is obtained from the attachment/detachment detection means 7 for detecting attachment/detachment, and the voltage change detection means 6 and the attachment/detachment detection means 7
When a telephone removal detection signal is obtained from telephone M
A hold control circuit comprising a hold means 8 that sets the hold state by short-circuiting L + = L 2 with a resistor R0, and resets the hold state when a connection detection signal of the telephone 2 is obtained from the attachment/detachment detection means 7. 9 is provided. Here, the attachment/detachment detection means 7 detects the control amount #j[L
A series circuit of an impedance element 7a and a DC power supply 7b connected in parallel to the male control circuits ML, ,L, and a rise detection circuit 7 that detects the rise of voltage change between the male control circuits ML, ,L.
c and a fall detection circuit 7d that detects the fall of voltage change, and the control amount #i L, 3, L
When the voltage between 4 and 4 rises, it is determined that the plug 3 has been pulled out from the telephone outlet 2 and the telephone 8!2 has been removed, and a removal detection signal ("H" level) is output, and the controller #!L, , when the voltage between L4 falls, it is determined that the plug 3 is inserted into the telephone outlet 1 and the telephone 8!2 is connected, and a connection detection signal ("H" level) is output. Further, the holding means 8 includes an AND circuit 8a to which the output of the voltage change detection means 6 and the output of the rise detection circuit 7c of the attachment/detachment detection means 7 are input; An AND circuit 8c to which the output of the falling detection circuit 7d is input, a delay circuit 8d that delays the output of the AND circuit 8c to form a reset signal for the R-S latch circuit 8b, and both AND circuits 8a and 8c are set, respectively. and a contact control circuit 8c which is input as a signal and a reset signal and controls the contact S0. When the output of the AND circuit 8a reaches the °゛H" level, the contact S is turned on and the resistor R0 is connected to the telephone # It is connected to iL1 and L2 to set the hold state, and when the output of the AND circuit 8c becomes "H" level, the contact S0 is turned off and the hold state is reset.

Hereinafter, the operation of the embodiment will be specifically explained based on FIG. 3. Note that FIG. 3(a) shows telephone #IL.

Voltage V1□ across L2, Fig. 3(b) shows control line L s
, L - is a time chart showing changes in voltage V34 between L and -.

Now, when the plug 3 of the telephone 2 is connected to any telephone outlet 1, the change in the voltage V12, ■ in the normal no-call state @T, the incoming call state T2 and the talk state T is as follows. The voltage waveform is as shown in the left half of Figure 3 (a) and (b), and the hold control circuit 9 does not operate (contact S remains in the off state), and the voltage waveform is normal regardless of the hold control circuit 9. A call is made. Note that tl is the time when the call is received, and t2 is the time when the call is started. Here, it becomes necessary to change the calling position during a call, and when the plug 3 of the telephone 2 is pulled out from the telephone outlet 1 at time t3, the in-begence element 4 connected to the control line L4 is removed. As a result, the control episode @L
The voltage 34 between 3 and L4 rises from the divided voltage E'' of the DC power supply voltage E by the inbegence element 4.7a to the DC power supply voltage E, and the telephone line L + = L due to the telephone 8!2 being removed. Voltage between 2 V12
stand up too. The rise of the voltage V 34 is detected by the rise detection circuit 7c of the attachment/detachment detection means 7, and the attachment/detachment detection means 7 outputs a detachment detection signal c''H'' level). On the other hand, the rise of the voltage V12 is detected by the voltage change detection means 6, and a rise detection signal (H" level) is output from the voltage change detection means 6. In this way, the removal detection signal and the rise detection signal are output at the same time. When this happens, the output of the AND circuit 8a of the holding means 8 becomes “H”.
” level, a set signal is input to the contact control circuit 8C, the contact S is turned on, and the resistor R8 is connected to the telephone line L.
+ -L 2 is connected and a pending state T7 starts.

Next, if you reconnect the plug 3 of telephone 2 to another telephone outlet 1 at point 1, telephone 2 will connect to telephone line #X.
2 and is now able to continue the call. At this time, control line L3. Since the in-begence element 4 is connected again when L and open, the voltage V34 drops. i7
The output of the falling detection circuit 7d becomes "H" level, and a connection detection signal is output. The other input terminal of the AND circuit 8C to which this connection detection signal is inputted is R.
Since the -S latch circuit 8b output is at the "H" level, the AND circuit 8C output becomes the "H" level when the connection detection signal is input, and a reset signal is output. When this reset signal is input to the contact control circuit 8e, the contact 80 is turned off and the pending state is reset. Further, the R-S latch circuit 8b is reset by a signal obtained by delaying this reset signal by the delay circuit 8d, and prepares for the next pending state. Also, pending letter 1! ! When T is set, the resistor R0 is disconnected and the voltage V12 rises, and when the call ends and the handset is taken down, the voltage V2 further rises at g L s, but this voltage At the rising point of voltage V
Since , does not change, the attachment/detachment detection means 7 does not output the removal detection signal, and the output of the AND circuit 8a remains at the "L" level, and the suspension means 8 of the suspension control circuit 9 malfunctions at the time of tswta. There's nothing to do. In addition, when the plug 3 of the telephone 1fi2 is pulled out from the telephone outlet 1 due to the no-call condition fiT, the voltage V 34 rises at the moment the plug is pulled out, and a disconnection detection signal is output from the attachment/detachment detection means 7. However, since the voltage ■1□ between the telephone lines L, , and L2 does not change, the rising detection signal is not output from the voltage change detection means 6, and at the time of L7, the hold means 8 of the hold control circuit 9 will not malfunction.

[Effects of the Invention] As described above, the present invention provides a telephone system in which a telephone call position can be freely selected by connecting a plug of a telephone to one of a plurality of telephone outlets to which telephone lines are wired. 17 Tsukuda 1 Xiang Attachment/detachment detection means detects attachment/detachment of a telephone depending on whether or not an invigorance element is connected between the lines; This device is equipped with a hold control circuit consisting of a hold means that sets the hold state by short-circuiting the line with a resistor and resets the hold state when a telephone connection detection signal is obtained from the attachment/detachment detection means. When the plug is removed from the Funcent, the hold control circuit operates and the telephone line is automatically placed on hold, and when the phone is plugged into an outlet and the outlet is reconnected, the hold status is automatically reset. Therefore, the telephone can be easily moved even during a call, and furthermore, there is an effect that the holding means does not malfunction when the telephone is moved in a non-call state at the end of a call.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, FIG. 1 is a telephone, 2 is a telephone, 3 is a plug, 4 is an impedance element, 6 is a voltage change detection means, 7
8 is a holding means, and 9 is a holding control circuit. Agent Patent Attorney Ishi 1) Chief Figure 7 4

Claims (1)

[Claims] (1) In a telephone system in which the call position can be freely selected by connecting the plug of the telephone to one of multiple telephone outlets to which telephone lines are wired, the control line is wired to the telephone outlet, and the plug is connected to the telephone outlet. Voltage change detection means includes an impedance element connected to the control line and detects a rise in telephone line voltage; and attachment/detachment detection means detects attachment/detachment of the telephone depending on whether an impedance element is connected between the control lines. When a rising detection signal is obtained from the voltage change detection means and a telephone removal detection signal is obtained from the attachment/detachment detection means, the telephone line is short-circuited with a resistor to set the telephone on hold and the attachment/detachment detection means disconnects the telephone. 1. A telephone system comprising a hold control circuit comprising a hold means that resets a hold state when a connection detection signal is obtained.