JPS59200570A - Terminal controller for wire telephone line - Google Patents

Abstract

PURPOSE:To secure prevention against an erroneous incoming call by inhibiting incoming call connecting operation based upon the detection output of a call signal detecting circuit when some terminal in a station originates. CONSTITUTION:When a call signal from a switchboard arrives at terminals L1 and L2, the call signal detecting circuit 23 detects it and outputs an H signal to an output line (a), and terminals A and B generate ringing tones. When the terminal A in the station originates, signals (l) and (l') are connected with low impedance in terms of DC and relay contacts K1 and K1', and K3 and K3' are turned on and as a result made to terminate the terminals L1 and L2 by a terminal A with low impedance. This is detected by the switchboard, which transmits a dial tone. Then, dial pulses of the terminal A are sent to the switchboard, and an OR gate 30 outputs only a low-level signal even if the call signal detecting circuit 23 detects it erroneously to output an H signal to the signal line (a), so that neither of relay contacts K2 and K2' turn on. Therefore, erroneous incoming to a terminal B due to the calling of the terminal A is prevented.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a terminal control device for a wired telephone line, and more particularly, to The present invention relates to a device for preventing erroneous calls from terminals.

[Technical background of the invention]

The main cause of such erroneous call behavior is the 16
This is because a calling signal detection circuit that detects a Hz calling signal mistakenly detects, for example, a dial impulse sent out when a certain terminal makes a call, as being a calling signal from the exchange.

Therefore, in the past, a circuit for preventing erroneous detection by the calling signal detection circuit was provided for each terminal. The principle of such a prevention circuit is that, for example, the dial impulse caused by a call from a terminal is a rectangular wave, and the ringing signal from an exchange is a sine wave, so the difference in waveform of both signals prevents false detection of dial impulses. This was to prevent other terminals from receiving erroneous calls. Other methods include those that prevent the above-mentioned erroneous detection based on the voltage difference between the calling signal and the dial impulse.

[Problems with background technology]

This conventional system is certainly effective for exchanges in which the dial impulse waveform is relatively close to a rectangular wave. However, it is known that large overshoots occur in exchanges such as doll exchanges due to their input impedance and line loss. In other words, in the case of such exchanges, the dial impulse is significantly different from the rectangular wave, so conventional circuits that prevent false detection operate reliably based on the difference in waveform between the rectangular wave and the sine wave. This often resulted in false detections.

Also, in the method using the voltage difference between the ringing signal and the dial impulse, Opage 1. If the voltage at the gate is high, there is a problem that reliable operation cannot be performed for the same reason.

Therefore, no conventional system has been able to reliably prevent erroneous calls regardless of the type of exchange to which the terminal is connected.

Furthermore, in the conventional system, each terminal is generally equipped with the above-mentioned prevention means, which results in high costs, and due to differences in detection times, the telephone rings after receiving a ringing signal from the exchange. The amount of time it takes to complete the process varies depending on the device, which can sometimes give users a sense of discomfort.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and provides a terminal control device for a wired telephone line that can perform a reliable operation to prevent erroneous calls in any line condition, regardless of the exchange to which the terminal is connected. The purpose is to

SUMMARY OF THE INVENTION Accordingly, the present invention provides a ringing signal detection circuit for detecting a ringing signal from an exchange and controlling incoming call connections to a plurality of terminals connected to the same wired telephone line based on the detection. a call detection means that is provided for common use in each terminal and detects when any one of the plurality of terminals makes a call; and an output of the ring signal detection circuit based on the detection output 1 of the call detection means; When a certain terminal in the station makes a call, the incoming call connection operation based on the detection output ζ of the paging signal detection circuit is prohibited from now on. Control methods for the control means include a method of interrupting the power supply to the calling signal detection circuit, and a method of causing the detection output of the calling signal detection circuit to be output but invalidating the detection output by another signal.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail according to embodiments shown in the accompanying drawings.

FIG. 1 shows a first embodiment of the invention. This embodiment shows a case where two terminals A and B are connected to the same wired line, and the contacts of each relay are 1' to 1', 2' to 2', and 2' to 2'.
, to 3. 3/ indicates that all meter contacts are in the OFF state. In this case, it is assumed that terminals A and B are telephones.

In FIG. 1, 20 is a relay contact with 1 and K,
/ drive circuit, 21 is the relay contact 2 and 2'
22 is a drive circuit for relay contacts 3 and 3/, a call signal detection circuit that detects a call signal (16 Hz) from an exchange (not shown) input through L2. The circuit 24 is a terminal Ll associated with hook-off or hook-on of the handset at terminals A and B.
, a voltage detector that detects a change in the DC voltage between L2, 2
5, 26 and 27 are set/reset flip-flops (hereinafter referred to as 5-RF/F).

Next, the specific operation of this embodiment will be explained in detail.

First, the case of incoming call operation will be explained.

For example, when receiving a call from another terminal, a switch (not shown)
When the calling signal (16H2) from the terminal reaches the terminal "1 rL2, the calling signal detection circuit 23 detects this and outputs a logic high level signal (hereinafter referred to as H signal) to the output line a. Of course, , when the above call signal is not detected, the output line a is at a low logic level (hereinafter referred to as a low signal), and this detection circuit 23 is, for example, a detection circuit based on the waveform or voltage difference shown in the conventional example. Good. By outputting the H signal to the above output line a, S -
RF/F25 is set and an H signal is output from the output line.

On the other hand, when terminals A and R are in standby mode, 5-RF/F
26 and 27 have been reset, and the signal lines c, dJ
This H signal is output. Therefore, the output e of the AND gate 28 becomes high level, and an H signal is output to each output line f, g, and h of the OR gates 29, 30, and 31. As a result, the relay drive circuits 20, 21, and 22 are put into a driving state, and each relay contact has a power output.
．． ni, ', ni2. 2', 3. Turn on 3'.

As a result, the calling signal from the exchange is supplied to terminals A and B, and each terminal A and B generates a ringing tone.

After that, if the handset of either terminal A or H is lifted, the hook switch of that terminal is closed and the terminal is in a talking state.

Next, when you hang up the handset at the end of the call, the terminal
The voltage between 1 and L2 changes from a low voltage of several volts to an open circuit voltage of 48V. The voltage detector 24 detects this and outputs an H signal to the output line i. Of course, when the handset is lifted up, the output line i is at a low level. This results in S-RF/F25.26.

27 is reset again and outputs an L signal to the signal line S and an H signal to the signal lines C and d. Therefore, the anime
The output e of the door becomes low level. Also, 5-RF/F
Since the outputs j of 26 and 27 are both at low level, the output lines f and g of OR gates 29, 30, and 31 are
, h output an L signal, which puts the relay drive circuits 20, 21, and 22 into a non-drive state, and the respective relay contacts Kl.

K,', 2. ni2', ni3. 3' off.

Next, when terminal A makes a call, ζ will be explained.

When the handset of terminal A is lifted, the hook switch is closed and a call is made, and the signal lines 7 and 1' are connected with low DC impedance. Along with this, the signal line 1 becomes low level due to the power supply voltage VCCI and the resistor 32. This state is logically inverted by the inverter 33 and an H signal is output to the signal line m, and as a result, 5-RF/F 26 is set and an H signal is output to the signal line. As a result, an H signal is output to each output line f, h of OR gates 29 and 31,
The relay drive circuits 20 and 22 enter the drive state, and the relay contacts are set to 1', 3. , turn on '. As a result, terminal L1. Since L2 is terminated with low impedance by terminal A, when the exchange detects this, the exchange transmits a dial tone.

After this, the operator turns the dial on terminal A and sends a dial pulse to the exchange. At this time, even if the calling signal detection circuit 23 erroneously detects this dial impulse and outputs an H signal from the signal line a, and an H signal is output from the signal line a, as described above, the 5-RF/F 26 is set and 5-RF/F27 is set, so an L signal is output to signal line C and signal line e becomes low level. Also, the signal line '' is also at low level. As a result, only a low level signal is output from the OR gate 30 at this time, and the relay drive circuit 21 outputs a 2. ' is never turned on. Therefore, an erroneous call received by terminal B due to a call originating from terminal A is reliably prevented.

Note that since terminal A and terminal B are connected in parallel, erroneous calls received by the terminal person due to a call originating from terminal B are also reliably prevented in the same way.

Furthermore, the operations associated with the termination of a call when a call is made are performed in the same manner as in the case of an incoming call, and as a result, all relay contacts are connected to , K,', K2. K2', K3.
3' is turned off.

FIG. 2 shows a second embodiment of the invention. This embodiment shows a case where two terminals C and D are connected to the same wired line, similar to the first embodiment shown in FIG. switch SOr
SO' + s and y SI' all indicate the off state. In this case as well, it is assumed that the terminals C and D are telephones, but in this embodiment, the footer switch S of each terminal C and D is assumed to be a telephone. ,
It is assumed that So', S, and Sl' are respectively interlocking two-contact switches.

In FIG. 2, the edict is a call signal (16
34 is a 4 drive circuit for relay contacts, 35 is a 5 drive circuit for relay contacts, and 36 and 37 are 5-RF/F.

First, specific operations in the case of an incoming call will be explained.

When a call signal from the exchange is received from another terminal and reaches L2, the call signal detection circuit 23 detects this and outputs an H signal to the output line n. As a result, the outputs of the OR circuits 38 and 39 become high level.
-RF/Fs 36 and 37 are sent, and H signals are output to output lines 0 and P. Therefore, the relay drive circuits 34 and 35 are in the driving state, and the relay contacts 4 + K5 are turned on.

As a result, the calling signal from the exchange is supplied to terminals C and D, and each terminal C and D generates a ringing tone.

After that, if the handset of terminal C is picked up, the switch So and the switch S linked to the switch So
. ' is turned on. Is this a signal line? , ? '
are connected with low DC impedance. Is there a signal line associated with this? becomes low level due to the power supply voltage vcc2 and the resistor 40. This state is logically inverted by the inverter 41, an H signal is output to the signal line r, and the output of the OR gate 42 becomes high level.

As a result, the power switch 4 of the calling signal detection circuit consisting of the power supply VCC 3, the transistor 43 and the resistor 44 is activated.
5 is off. After this, the calling signal detection circuit 23 does not operate in the talking state. This is to reduce power consumption of the paging signal detection circuit.

Note that the calling signal detection circuit 23 is inactive and the signal line n
During a short period of time when the signal line r and signal line n change from high level to low level, signal line r and signal line n are at high level. Therefore, the output of the AND gate 46 becomes high level, and the output of the OR gate 47 also becomes high level. As a result, 5-RF/
F37 is reset, the drive circuit 35 goes into a non-drive state, and relay contact 5 is turned off. This means that when terminal C answers an incoming call, the terminal
” Since there is no need to connect it to 2, I decided to disconnect it.

Next, when the handset of terminal C is put down at the end of the call, footer switch S is activated. , So' is cut and the signal line F
is at a high level. This state is logically inverted by inverter 4, and the signal line becomes low level.As a result,
The output of the OR gate 42 is at a low level (the output of the inverter 49 is also at a low level). It is.

Then, the S-RF/F 36 and 37 beams are set. As a result, the relay drive circuits 34 and 35 are in a non-driving state, and the relay contacts 5 and 5 are turned off and in a standby state. Of course, in this embodiment circuit, as described above, relay contact 5 is turned off in advance after terminal C is hung up.

Since terminals C and D are connected in parallel, they operate in the same manner as described above even when the other terminal responds to an incoming call.

Next, a case will be described in which, for example, terminal C makes a call.

When you lift the handset of terminal C, an interlocking hook switch S appears.

, So' closes and becomes a calling state, and the signal line ? , ? '
are connected with low DC impedance.

Along with this, the signal line is connected to the power supply voltage vcc2 and the resistor 40.
And it becomes a lower level than Masako. This state is logically inverted by the inverter 41, and an H signal is output to the signal line r, and the 5-RF/F 36 is set via the OR gate 38, and the ■ signal is output to the signal line 0. As a result, the relay drive circuit 34 enters the drive state and turns on the relay contact 4. On the other hand, since the output of the OR gate 42 also becomes high level, the power switch 45 is turned off, and the calling signal detection circuit becomes inactive.

Therefore, even if a dial l--on is subsequently transmitted from the exchange and the operator turns the dial on terminal C to send a dial pulse to the exchange, the ring signal detection circuit 23 is in an inactive state. , erroneous detection by the calling signal detection circuit can be reliably prevented.

The operation when the terminal makes a call is also the same as described above, and erroneous detection by the calling signal detection circuit can be reliably prevented.

FIG. 3 shows a third embodiment of the present invention. The basic operation of this embodiment is similar to the embodiment shown in FIGS. 1 and 2, but in this case, wireless terminal F and terminal G are connected to the same wired line via master station F. It is assumed that terminals F and G are telephones.

In FIG. 3, the terminal G connects to the master station E via the terminal board 51.
The terminal F is a mobile radio telephone mounted on a car or the like, for example. The relay drive circuit 52 has relay contacts, K, K6. The drive circuit of , relay drive circuit 53 is connected to the relay contact, 7'
The relay drive circuit 54 is a drive circuit with eight relay contacts. However, K6 is a break contact of the relay drive circuit 52, and when the relay drive circuit 52 enters the drive state, K6 is turned off and the power supply to the calling signal detection circuit 23 is cut off.

The detection operations of the calling signal detection circuit 23 and voltage detector 24 are similar to those shown in FIG. 1 above.

Next, this embodiment m will be explained.

I will explain the incoming call operation. When a call signal (16Hz) from an exchange (not shown) arrives at terminal "+ +" 2 in response to a call from another terminal, the call signal detection circuit 23 detects this and outputs a ■ signal to the output line t. . By kneading, the s-RF/F 56 is set and an H signal is output to the output line U. Therefore, the outputs of OR gates 57 and 58 become high level, driving relay drive circuits 52 and 53. As a result, the make contacts 6', ``, 2, 2, 2'' are turned on, but the break contacts 6 are turned off, and the power supply to the ringing signal detection circuit is interrupted. In this state, the ringing signal detection circuit does not operate.

On the other hand, the control circuit 5 outputs the H signal to the signal line U.
9 is detected, and the control circuit 59 performs an operation to control the connection of the wireless terminal F. First, a radio wave modulated with a control signal is transmitted to the terminal F via the transmitter 60 and the antenna 61. Terminal F receives the radio waves via the antenna 62 and receiver 63, demodulates the radio waves with the receiver 63, and then sends them to the control circuit 64. Similarly to the above, the control circuit 64 returns radio waves modulated with the control signal to the master station F via the transmitter 65 and antenna 66. After this control signal is demodulated by the receiver 68 via the antenna 67, it is sent to the control circuit 59.

As a result, a wireless link between the master station E and the wireless terminal F is configured.

Thereafter, the control circuit 59 transmits radio waves modulated with the incoming call signal to the wireless terminal F via the transmitter 60 and the antenna 61.

This is demodulated by the receiver 63 via the antenna 62, and when the control circuit 64 reads this, the control circuit 64 generates a ringing sound via the sounder 69.

Of course, before and after this, the terminal G generates a ringing tone in response to the ringing signal from the exchange.

If the terminal G responds in this state, the hook switch of the terminal G is closed and the terminal G enters the talking state.

The operation after the end of the call is the same as the embodiment shown in Fig. 2 or 3, and the relay contacts are 6', K6'', and K7.
K7' is turned off and the ringing signal detection circuit is restarted.

Next, when terminal F responds, the operator of terminal F first turns on switch 70 (corresponding to a hook switch on a wired telephone). The control circuit 64 detects this and stops sending out the aforementioned control signal, turns on the audio circuits in the receiver 63 and the transmitter 65, and transmits the transmitter 7.
7 and receiver 78 are operated. When the control circuit 59 of the master station E detects that the control signal has stopped, the control circuit 59 outputs an H signal to the signal line V. When this button is pressed, the relay drive circuit 54 enters the drive state, and the relay contact 8 is turned on. In conjunction with this, the control circuit 59 operates the receiver brocade and the audio circuit in the transmitter 60, discriminates between the transmitted wave and the received wave via the hybrid circuit 55, and puts the terminal F into a talking state. By adopting such a system, there is no need to newly provide the terminal F with a ringing signal detection circuit for detecting a ringing signal and preventing erroneous call arrival.

Next, when the call ends, the operator turns off the switch 70 of terminal F. The control circuit 64 detects this, sends out radio waves modulated with the control signal via the transmitter 65 and the antenna 66, and then turns off the transmitter 65 to put the wireless terminal F into a standby state. The control signal is demodulated by a receiver 68 in the master station E and applied to the control circuit 59. As a result, the control circuit 59 turns off the transmitter 60, sets the signal line V to a low level, puts the relay drive circuit 54 into a non-drive state, and turns off the relay contact 8. As a result, the voltage between the terminals L1 and 52 changes from a low voltage of several volts to an open circuit voltage of 48V. Voltage detector 24 detects this and outputs an H signal to output line W. S-RF/F56
is recent 7, and the output U becomes low level. Therefore, the relay drive circuits 52 and 53 are in a non-drive state, and the relay contacts are set to ', 6', 7. Then, the break contact 7' is turned off and the break contact 6 is turned on to restart the ringing signal detection circuit 23.

Next, a case where wireless terminal F makes a call will be explained.

When the switch 70 of the terminal F is turned on, the control circuit 64 detects this and sends radio waves modulated with the control signal to the transmitter 65,
It is transmitted to the master station E via the antenna 66. After this control signal is demodulated by the receiver 68 via the antenna 67, it is sent to the control circuit 59. The control circuit 59 transmits radio waves modulated with control signals in the same manner as described above to the terminal F via the transmitter 60 and the antenna 61, and operates the hybrid circuit to establish a wireless line between the master station E and the terminal F. form. Along with this, the control circuit 59 outputs an H signal to the signal line V.

This puts the relay drive circuits 52 and 54 into the drive state, resulting in relay contacts ', 6'',
At the same time, the break contact 6 is turned off and the ringing signal detection circuit becomes inactive. Therefore, even if the operator sends out a dial pulse from the terminal F after this, the ringing signal detection circuit 23 is in an inactive state, so that erroneous detection by the ringing signal detection circuit 23 can be prevented. .

The operation after the call ends is the same as the operation shown in the case of an incoming call,
Omitted.

The embodiment shown in FIG. 3 described above shows an example of a case where another terminal (terminal G) is connected to a terminal (corresponding to base unit E and terminal F) having a built-in means for preventing erroneous call arrival. Therefore, if a wired telephone is always installed in parallel with the base unit, such as a cordless phone, if the base unit is equipped with the above-mentioned means to prevent erroneous calls, it is possible to install the base unit in parallel with the base unit. It is possible to prevent erroneous calls from being received by other terminals due to calls made by all connected terminals.

By the way, the calling signal detection circuit, which is a component of the present invention,
A call detection means and a means for setting the output of the calling signal detection circuit to an inactive level based on the detected output ζ of the call detection means are configured in one housing, and a plurality of terminal connections provided in the housing are provided. By connecting multiple terminals with the same wired telephone line to the terminal, it is possible to reliably prevent erroneous calls to the multiple connected terminals without modifying the circuit of the conventional wired telephone terminal. . Further, the casing may be configured to be shared with, for example, the casing of one telephone terminal among a plurality of terminals.

Note that the configuration of the present invention is not limited to the embodiments described above. For example, the configuration may be a combination of the embodiment shown in FIG. 1 and the embodiment shown in FIG. 2, and the circuit configuration of each part may be completely arbitrary.

In short, there is a ring signal detection circuit that detects a ring signal from an exchange, a call detection means that detects a call from a terminal, and a system that forcibly outputs the output of the ring signal detection circuit based on the detection output of the call detection means. It is only necessary to include a control means for setting the control device to an inactive level.

Further, in the above-described embodiment, a case was described in which a dial impulse is sent when a terminal makes a call, but the present invention is capable of forcibly setting the output of the ringing signal detection circuit to an inactive level at the same time as detecting a call. Therefore, it is possible to reliably prevent erroneous detection even for terminals that send signals other than dial pulses, such as high-level data signals, which may cause erroneous detection.

Furthermore, although some recent private branch exchanges (PBXs) accept dial impulses and signal formats other than the above-mentioned dial impulses, according to the present invention, both of these signal formats can be accepted. Since false detection can be reliably prevented, the time difference (23) mentioned above can be eliminated.

It is also effective for PBX.

By the way, the terminal referred to in the present invention is not limited to a telephone, but may also include a facsimile, a data communication device, etc. that are connected to a wired telephone line and receive a call by detecting a ringing signal from an exchange. Of course, it includes all devices that are in this state.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to reliably prevent erroneous calls irrespective of whether the terminal is connected or not, regardless of the line state, and also when multiple terminals are connected to the same wired telephone line. Since there is no need to provide a separate erroneous call prevention circuit for each terminal, it has the excellent effect of preventing erroneous calls at an extremely low cost even when many terminals are connected. . Further, according to the present invention, when performing incoming call connection control, it can be applied uniformly to all terminals, so that the incoming call connection control can be applied uniformly to all terminals, so that the incoming call connection control can be applied uniformly to all terminals. Until ringing occurs between terminals (24)

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention;
The figure is a circuit diagram showing a second embodiment of the invention, and FIG. 3 is a circuit diagram showing a third embodiment of the invention. A, , B, C, D, F, G... terminal, 20, 21', 22. 34, 35, 52, 53, 54...Relay drive circuit, 23...Call signal detection circuit, 24...
Voltage detector, 45・Power switch circuit, 51...Terminal board, 55...Hybrid circuit, 59, 64...
Control circuit, 60, 65...Transmitter, 63, 68
Receiver, 69 Sounder, 77... Transmitter, 78... Handset Patent attorney Kensuke Norichika (and one other person)

Claims (6)

[Claims] (1) In a wired telephone line terminal control device that controls incoming call connections to a plurality of terminals connected to the same wired telephone line based on the detection output of a ringing signal detection circuit that detects a ringing signal from an exchange, call detection means for detecting that any one of the terminals has made a call; and control means for forcibly setting the output of the ringing signal detection circuit to an inactive level based on the detection output of the call detection means. A terminal control device for a wired telephone line, characterized in that: (2) A terminal control device for a wired telephone line as set forth in claim (1), wherein the control means is means for stopping power supply to the calling signal detection circuit. (3) A terminal control device for a wired telephone line according to claim 1, wherein the control means is a means for invalidating the detection output output from the calling signal detection circuit. (4) A terminal control device for a wired telephone line as set forth in claim 5, wherein the 16f detection means is provided separately for each of a plurality of terminals. (5) The $54 detection means includes a switch means that is connected in series to each terminal and performs a switching operation to connect or disconnect the terminal from the wired telephone line, and a means for applying a predetermined DC potential to the terminal side of the switch means. 4. A terminal control device for a wired telephone line according to claim 4, further comprising means for detecting a change in the DC potential due to a calling operation of the terminal. (6) The calling signal detection circuit, the call detection means, and the control means are housed in one housing, and the housing is provided with a connection terminal for connecting a plurality of terminals. A terminal control device for a wired telephone line according to any one of items (1) to (5).