JP2861587B2 - Dial-in processing circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a dial-in processing circuit used for receiving a so-called dial-in service.

[0002]

2. Description of the Related Art Recently, a dial-in service has been widely spread. In such a service, as shown in FIG.
(N1 to Nn) are connected via the dial-in adapter AD, and a different telephone number is assigned to each of the communication terminals N1 to Nn. Only one corresponding communication terminal N can be called and an incoming call can be made. That is, in such a dial-in service, an external telephone D
When a dial call is made from, for example, as shown in FIG.
First, a call signal S1 is transmitted from the telephone exchange to the dial-in adapter AD to receive a call (line connection), and then the telephone exchange transmits a call telephone number to the dial-in adapter AD by a push tone signal S2. come. After that, the dial-in adapter AD sends a pseudo call signal S3 to the communication terminal N corresponding to the telephone number corresponding to the push tone signal S2 in a state where the line is released. As a result, when the handset of the communication terminal N receiving the pseudo call is picked up and there is an incoming call, the communication terminal N is connected to the telephone line L, and thereafter, a desired call or facsimile communication can be performed. Is configured.

[0003] According to the use of the dial-in adapter AD, there is no problem when making a call when a power failure occurs, but the adapter A is used when a call is received.
Since each circuit in D cannot be controlled to a predetermined state, it is impossible to make an incoming call in accordance with normal dial-in processing. On the other hand, the dial-in processing is set in advance so as to be performed according to a certain processing procedure, and it is necessary to open the line once and then connect the line again after the line connection after receiving the call signal S1. Unless such a line is temporarily released, the telephone exchange cuts off the telephone line, so that subsequent telephone calls and communications cannot be performed.

Therefore, conventionally, in order to receive a telephone call at the telephone N2 and perform a telephone call at the time of a power outage, first, after a call signal S1 is transmitted from the telephone exchange, the telephone set N2 picks up the handset and performs an incoming call. After
When the push tone signal S2 is confirmed, the handset is restored and the telephone line is opened once the push tone ends, and after a few seconds, the handset is picked up again and the line is connected. Steps 300 to 308 of the flowchart shown in FIG. 7 show the procedure of the incoming call operation of the telephone at the time of power failure.

[0005]

However, in the above-described conventional device, it is necessary to perform operations such as returning the handset after confirming the push tone signal and picking up the handset again, so that the operation is very troublesome. If this operation is inconvenient and the user does not perform the operation within a certain period of time, the telephone exchange will cut off the telephone line without any permission and the telephone call will be impossible (steps 308 and 31 in FIG. 7).
0). Incidentally, as means for solving such a difficulty, means for backing up all the circuits in the dial-in adapter with a battery is also conceivable. However, such a means for backing up all circuits requires the use of a large-capacity battery, which leads to an increase in size and cost, and has the drawback that a short backup time is required. Not.

[0006] The present invention has been proposed in view of the above points, and is troublesome in that even if a power failure or the like occurs, the telephone handset once picked up is recovered and then picked up again as in the prior art. Provided is a dial-in processing circuit that allows a desired telephone to receive a call with a simple operation and perform a telephone call without performing a manual operation and without causing a drawback such as increasing the capacity of a backup power supply. That is its purpose.

[0007]

A dial-in processing circuit according to the present invention proposed to achieve the above object has a power cutoff detecting means for detecting a stop of power supply to a power supply circuit, Backup power supply, when the power supply to the power supply circuit is stopped by the power cut-off detecting means, the telephone line wiring section is connected to a predetermined communication terminal, and the telephone The off-hook detection of the communication terminal in response to the call and the temporary release control of the telephone line after the detection of the off-hook are performed by the power of the backup power supply for power-off.

[0008]

In the dial-in processing circuit having the above-mentioned configuration, when the power cutoff detecting means detects the stoppage of the power supply to the power supply circuit due to a power failure or the like, the wiring section of the telephone line is determined in advance. While being connected to a predetermined communication terminal, a backup power supply for power shutdown is enabled. Then, in such a state, a call signal is transmitted from the telephone exchange when an external call is made, and when there is an incoming call by picking up the handset of the predetermined communication terminal, detection of off-hook by picking up the handset, and The temporary release control of the telephone line after the detection of the off-hook is performed by the power of the backup power supply. Therefore, even during a power outage, the line is temporarily released after the communication terminal receives an incoming call, and the operation is performed only by once picking up the handset in response to a telephone call from the telephone exchange. A call can be made with the calling party. The backup power supply does not back up the entire circuit of the dial-in processing unit, but can perform off-hook detection and temporary release control of the telephone line. Therefore, it is not necessary to increase the capacity so much, and the backup time is reduced. Can be lengthened.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a dial-in adapter by accommodating a dial-in processing circuit A according to the present invention in an adapter case formed separately from a communication terminal such as a facsimile apparatus F and telephones D1 and D2. It is a block diagram showing an example in the case of having performed.

The dial-in processing circuit A includes a changeover switch 1 for switching and connecting any one of the communication terminals F, D1, and D2 to the telephone line L, and an NC switch 3 for temporarily opening the telephone line L. And a signal processing unit 2 for controlling these switches and other components, and also a backup power supply 10 connected to a power supply circuit 9 and the like. Here, the changeover switch 1 is configured by a relay switch or the like that switches connection of the contacts a to e with respect to the wiring portion L1 connected to the connection terminal TL of the telephone line L, and the contact a is a dial-in processing circuit. OFF contact to be connected in the initial state of standby for incoming call of A, contact b is a contact to which a predetermined resistor R is connected, and contacts c to e are facsimile machines F and telephones D1, D2 connected to connection terminals T1 to T3, respectively. Is conducted.

In addition to the NC switch 3, the wiring section L1 includes an off-hook detecting circuit 4 for detecting an off-hook caused by picking up a handset of the communication terminals F, D1, D2, and the communication terminals F, D1, D2. A pseudo call signal generation circuit 5 for transmitting a pseudo call signal to the telephone call, a call signal detection circuit 6 for detecting a call signal (16 Hz analog signal) transmitted from the telephone exchange, and a pseudo call signal transmitted from the telephone exchange. A predetermined push tone signal (D
A push signal detection circuit 7 for detecting TMF) is connected.

The power supply circuit 9 is wired and connected to each of the circuits so as to supply power to each of the above circuits. The power supply circuit 9 includes a voltage drop detection circuit 11 (an example of a power cutoff detection means of the present invention). Is connected to the power supply circuit 9 and power is not supplied to the power supply circuit 9 due to a power failure or the like, and a predetermined signal is transmitted to the signal processing unit 2 when the voltage drops below a predetermined value. . Further, for example, a rechargeable battery or the like is used as the backup power supply 10, which is normally charged with power supplied from the power supply circuit 9, but the power supply from the power supply circuit 9 to each circuit is stopped. In this case, the power is immediately supplied from the backup power supply 10 to a predetermined circuit. The backup power supply 10 does not supply power to all circuits. For example, in the dial-in processing circuit A, the signal processing unit 2, the storage unit 8 for the signal processing unit 2, the off-hook detection circuit 4, and the NC switch It is merely configured to be able to supply power to 3 and the like (specific wiring is not shown).

On the other hand, the signal processing unit 2 controls each part of the dial-in processing circuit according to a different operation procedure when the voltage drop detection circuit 11 detects the voltage drop and when the voltage drop detection circuit 11 does not detect the voltage drop. Is what you do. That is, when no voltage drop is detected, the ringing signal detection circuit 6
Receives a predetermined call signal from the telephone exchange, controls the changeover switch 1 to connect the telephone line L to the contact b, and when the push signal detection circuit 7 detects a push tone signal, The telephone number is decoded from the tone signal, and the switch 1 is switched and controlled to connect any one of the communication terminals F, D1, and D2 corresponding to the telephone number to the telephone line L. After the line switching, the signal processing unit 2
With the switch 3 open, a pseudo-call signal is output from the pseudo-call signal generation circuit 5 and then the off-hook detection circuit 4
When an off-hook of a predetermined communication terminal is detected by NC, NC
The switch 3 is returned to the closed state, and thereafter, a predetermined communication terminal is connected to the line, so that a call or a facsimile communication is controlled.

On the other hand, when the voltage drop of the power supply circuit 9 is detected, the contact of the changeover switch 1 is connected to a predetermined contact, for example, a telephone D2 whose handset is scheduled to be picked up in the event of a power failure. Contact e. This can be performed by setting the changeover switch 1 so that it automatically returns to the contact point e by its own spring pressure when the power supply to the changeover switch 1 is stopped. However, the connection of the contact point e can be performed by supplying the power of the backup power supply 10 to the changeover switch 1. When the off-hook detection circuit 4 detects an off-hook after receiving a call signal from the telephone exchange in the above state, the signal processing unit 2 immediately opens the NC switch 3 and immediately returns to the closed state. Is controlled.

Next, the dial-in processing circuit A having the above configuration
An example of use and the operation will be described. First, when a situation such as a power failure has not occurred and the voltage drop detection circuit 11 has not detected a voltage drop, the dial-in processing circuit A exhibits the following general dial-in processing function. . That is, different facsimile machines F and telephones D1 and D2 connected to the dial-in processing circuit A are respectively assigned different telephone numbers in advance. When a call is made from the telephone, first, a call signal as a 16 Hz analog signal is transmitted to the dial-in processing circuit A from the telephone exchange.

Then, since this call signal is detected by the call signal detection circuit 6, the changeover switch 1 connects the telephone line L to the contact b. As a result, the telephone line L forms a closed loop with the resistor R. After that, a predetermined telephone number is transmitted from the telephone exchange as a push tone signal S2. The push tone signal S2 is detected by the push signal detecting circuit 7 and demodulated. The number is decrypted. Therefore, the signal processing unit 2
When the communication terminal corresponding to the telephone number is, for example, the facsimile machine F, the switch of the changeover switch 1 is controlled to the contact c and the pseudo call signal generation circuit 5 outputs the pseudo call signal S3. As a result, the line is once released, and the facsimile machine F that has received the call arrives. Next, since the incoming call of the facsimile apparatus F is detected by the off-hook detection circuit 4, the NC switch 3 returns to the closed state at this time, the facsimile apparatus F is connected to the telephone line L, and thereafter the facsimile apparatus is operated normally. Communication is possible. Steps 200 to 208 in the flowchart of FIG. 3 show the above operation procedure.

On the other hand, unlike the above, when a predetermined power supply to the power supply circuit 9 is stopped due to a power failure or the like, the voltage drop detection circuit 11 detects a voltage drop, and this is detected by the signal processing unit 2.
In such a case, the dial-in processing circuit A performs the following operation control. First, when a predetermined power supply to the power supply circuit 9 is stopped, the backup power supply 10 functions, and necessary power is supplied to specific parts such as the signal processing unit 2, the NC switch 3, and the off-hook detection circuit 4. You. No power is supplied to the call signal detection circuit 6 or the push signal detection circuit 7 other than these. Also,
When the power supply to the changeover switch 1 is stopped, the changeover switch 1 naturally returns to a predetermined contact e. As a result, the wiring section L1 of the telephone line L and the telephone D2 are connected.

Next, when a calling signal is transmitted from the telephone exchange in the above state, the calling bell of the telephone D2 rings, and if the handset is picked up within a predetermined time, the incoming call is made. Then, a push tone signal is transmitted from the telephone exchange, but the handset of the telephone D2 is picked up by the off-hook detection circuit 4 backed up by the backup power supply 10.
And is accurately detected. When such off-hook detection is performed, the NC switch 3 whose power is also backed up operates properly, returns to the closed state after temporarily opening the line. By detecting the temporary release of the line, the telephone exchange connects the line between the calling side and the telephone D2, so that the telephone D2 can then communicate with the calling side. Step 1 of the flowchart of FIG.
Reference numerals 00 to 108 show the above operation procedure. In the flowchart, only the picking up of the handset in step 104 is performed manually, and the rest is performed automatically by using the backup power supply 10 or the like. is there.

In the above embodiment, the dial-in processing circuit A
Is described as an adapter separate from various communication terminals, but the present invention is not limited to this. For example, a dial-in processing circuit may be integrated into the body of the facsimile apparatus. FIG. 4 shows an example of such a case. In the facsimile apparatus FA shown in FIG. 4, the signal processing section 2a of the facsimile main body Fa is shared as the signal processing section of the dial-in processing circuit Aa to simplify the circuit configuration. It is intended. In addition, the present invention is configured as a configuration incorporated in a facsimile apparatus by connecting a signal processing unit of a dial-in processing circuit to a signal processing unit of a facsimile via a bus line or the like as an embodiment other than that shown in FIG. Is also good. As described above, the dial-in processing circuit according to the present invention may be any one of a form incorporated in a facsimile apparatus or the like and a form constituted solely.

[0020]

As can be understood from the above description, according to the dial-in processing circuit of the present invention, even if a power failure or the like occurs, the telephone handset once taken up as in the prior art is re-used. There is no need to perform the troublesome operation of returning and picking up the phone, and it is convenient because the call can be made only by picking up the first handset at the time of calling the telephone, and it is convenient for the telephone exchange side to The effect is obtained that the fear that the telephone line is cut off can be appropriately eliminated. In addition, the backup of power by the backup power supply does not cover all the circuits of the dial-in processing circuit, but only specific circuits and switches. It is also possible to eliminate such an increase in size, to obtain an excellent effect that the whole can be manufactured inexpensively and small, and the backup time can be extended.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a hardware configuration of a dial-in processing circuit according to the present invention.

FIG. 2 is a flowchart illustrating an example of a processing procedure when a power failure occurs in the dial-in processing circuit according to the present invention.

FIG. 3 is a flowchart illustrating an example of a normal dial-in processing procedure during a non-power failure.

FIG. 4 is a block diagram showing another example of the hardware configuration of the dial-in processing circuit according to the present invention.

FIG. 5 is an explanatory diagram showing an outline of a dial-in service.

FIG. 6 is a time chart showing an example of a dial-in processing procedure.

FIG. 7 is a flowchart showing a conventional processing procedure at the time of a power failure.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 changeover switch 2, 2 a signal processing unit 3 NC switch 4 off-hook detection circuit 5 pseudo call signal generation circuit 6 call signal detection circuit 7 push signal detection circuit 8 storage unit 9 power supply circuit 10 backup power supply 11 voltage drop detection circuit (power supply cutoff detection Means) A, Aa Dial-in processing circuit F Facsimile machine D1, D2 Telephone L Telephone line L1 Wiring unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) H04M 3/02-3/06 H04M 11/00-11/10 H04M 19/00-19/08 H04Q 3 / 58-3/62

Claims (1)

(57) [Claims] When an interruption of power supply to a power supply circuit is detected by a power cut-off detecting means, a wiring section of a telephone line is connected to a predetermined communication terminal, and communication for a call from a telephone exchange is performed. A dial-in processing circuit, wherein detection of an off-hook of a terminal and control for temporarily opening a telephone line after the detection of the off-hook are performed by the power of a backup power supply for power-off.