JPH0810984Y2 - Telephone line terminal equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention connects a telephone line to a terminal having a modem and a telephone via a change-over switch in a circuit changing means so as to be selectively switchable. Further, the present invention mainly relates to telephone line terminal equipment such as a facsimile equipped with a microcomputer for controlling the switches in the circuit switching means.

[Prior Art] An example of the above-mentioned telephone line terminal equipment is a facsimile machine shown in FIG.

This device connects a telephone line (1) to a circuit switching means (hereinafter referred to as NCU) (2) including a relay circuit and the like, and a modem (4) is connected via a changeover switch (3) in the NCU (2). ) And a telephone (5).

The modem (4) and the NCU (2) are connected to and controlled by a microcomputer (hereinafter referred to as a microcomputer) (6), and data is exchanged between the modem (4) and the microcomputer (6). Then, the printing device (7) and the reading device (8) as a facsimile connected to the microcomputer (6) operate.

The NCU (2) includes a known pulse dial circuit, ringer detection circuit, and the like.

[Problems to be Solved by the Invention] As described above, the telephone line (1) is switched and connected to the modem (4) and the telephone (5), but the connection is completely cut off even for a moment at the time of the switching. Then, communication is interrupted, so that the changeover switch (3) in the NCU (2) uses a so-called continuous contact in which one of the contacts is always closed.

However, this continuous contact is more expensive than the so-called transfer contact in which the switch terminal simply moves between the contacts and there is a moment when both contacts open, and the continuous contact with high withstand voltage is still present. Due to technical difficulties, there is no highly reliable one, and in the case of equipment for foreign countries, etc. where the connection part is a safety standard requiring high withstand voltage, in order to increase the withstand voltage of this part Requires a special device or circuit.

 This invention eliminates the above inconvenience.

[Means for Solving the Problem] Therefore, the present invention provides a device such as that described above with a bypass line that bypasses the telephone line and connects to the terminal side by bypassing the changeover switch, and an opening / closing switch is provided on this bypass line. It is proposed to provide an opening / closing switch control means for inserting and controlling the opening / closing switch in the microcomputer and closing the opening / closing switch at least during the switching operation of the changeover switch to the modem side.

[Embodiment] FIG. 1 and FIG. 2 show a first embodiment.

In FIG. 1, (10) is a telephone line, (11) is a connection line to a telephone (12), and (13) is a connection line to a modem (not shown). This circuit diagram is NCU (2). And mainly a microcomputer (14) for controlling each relay and the like in the NCU.

As is well known, the NCU includes a pulse dial circuit (15) and a ringer detection circuit (16). The pulse dial circuit (15) includes a switch (17) operated by a relay C, a capacitor (C1), and a resistor (R1). It consists of a snubber circuit.

(R2) is a dial make resistance, (CH1) is a choke coil, and (R3) is for fine tuning the DC resistance of the modem circuit.

And, the changeover switch (18) at the NCU entrance of the telephone line (10) uses a transfer contact,
A bypass line (19) is connected to the modem side, bypassing the switch (18), and a transfer contact open / close switch (20) is also inserted in the bypass line (19).

Open / close switch (20) and pulse dial circuit (15) above
The open / close switch (21) consisting of the transfer contact is operated by the same relay B, the changeover switch (A) is operated and controlled by the relay A, and the three relays A, B, and C together with the relay C are microcomputer ( Operation is instructed at a predetermined timing by 14).

Although each relay and each switch in FIG. 1 are in the off state (on-hook state), each relay A, B, C is operated by the microcomputer (14) at the timings shown in FIGS. In one embodiment, the changeover switch (18)
Is switched to the modem side, relay B is always controlled to be ON.

That is, FIG. 2 is a time chart at the time of fax reception, FIGS. 3 (a), (b) and (c) are time charts at the time of fax transmission, and FIG. 3 (a) is an external telephone (12).
Fig. 3 (b) when dialing using
Is for dialing using the dial keys on the fax side, and Fig. 3 (c) shows that for fax transmission, where the fax itself dials within itself by the operator pushing the dial number. There is. First, referring to FIG. 2, that is, during reception, the telephone line is connected to the telephone (12) side in the standby state, and the relays A, B and C are all OFF (state shown in FIG. 1).
(Relay C may be ON). When a ringing signal is detected by the ringer detection circuit (16) at the time of arrow (a-1), the signal is sent to the microcomputer (1
4) It is taken into the opening / closing switch control means (22), the control means (22) issues an operation command to the relay B, the relay B is immediately turned on, and the relay C is turned on.
Turn it off.

Then, since the bypass line (19) is closed, the relay A is next turned on, and the switch (18) including the transfer contact is switched to the modem side.

Next, the transmission of FIG. 3 (a) will be described. In the standby state (FIG. 1), similarly, the telephone line is connected to the telephone side, and all the relays A, B and C are turned off. Dialing is performed by the external telephone (12) during the standby state, and the other party responds.

When the operator presses the send button (23) (Fig. 1) at the time point of the arrow (a-2) after the other party comes out, the signal is taken into the control means (22) in the microcomputer. , If relay B is turned on immediately and relay C is turned on, turn it off.

Then, the bypass line (19) is closed, the relay A is subsequently turned on, and the switch (18) composed of the transfer contact is switched to the modem side.

Therefore, the telephone line is not disconnected but remains connected.

Next, the transmission time of FIG. 3B will be described. In this transmission method, when the operator presses the off-hook button (24) on the fax side at the time of arrow (a-3), the signal is transmitted to the control unit. When the relay B is taken into the means (22) and the relay B is turned on for a predetermined time (t1) immediately, the relay C is turned on, and when the relay C is turned on, dialing is enabled and dialing is performed. The length of this time (t1) can be arbitrarily changed by changing the program in the microcomputer (14), but it is necessary to be at least longer than the time required for switching the relay A.

Therefore, with the bypass line (19) closed, the switch (18) formed of the transfer contact switches to the modem side.

Further, FIG. 3B shows the case where the dial pulse is "2" as an example.

Then, when the transmission button (23) is pressed by the operator at the time of arrow (a-4), the relay B is turned on again, immediately after which the relay C is turned off and the transmission is started at the time of arrow (a-5). To be done.

Next, the transmission method of FIG. 3C will be described. In this method, the operator inputs the number of the destination dial during standby, and the operator also presses the transmission button (23) at the time of arrow (a-6). Then, in the same manner as above, relay B turns on immediately, then relay A turns on and the telephone line is switched to the modem side. At the same time, the dial tone is detected on the modem side to determine whether communication is possible, and if possible, At the time of the arrow (a-7), the relay C is turned on to transmit the dial pulse of the dial number previously input by the operator (the dial pulse is "2" also in this example), and the arrow (a- Transmission is automatically started at the time of 8).

Therefore, in both cases, the telephone line is switched from the telephone side to the modem side through disconnection through transmission and reception.

The first embodiment shown in FIGS. 1 to 3 is the bypass line (1
Although 9) was directly connected to the modem side, this bypass line can also be connected to the pulse dial circuit (15).

That is, this will be described below as a second embodiment with reference to FIGS.

The circuit diagram of FIG. 4 differs from that of FIG. 1 in that the bypass wire (25) from the telephone line (10) side of the changeover switch (18) is connected to the switch (17) of the pulse dial circuit (15). Connected point and changeover switch (18) ON
Open / close switch whose side contacts are controlled by relay B (20)
Is connected to.

As a result, in the first embodiment, the action of preventing disconnection of the telephone line (10) during the transfer of the changeover switch (18) was performed by turning on the relay B, whereas in the second embodiment. This is done by turning on relay C.

That is, the operation will be described based on a time chart regarding reception and three types of transmission methods, as in the first embodiment.

FIG. 5 is a time chart at the time of fax reception, and FIGS. 6 (a), (b) and (c) are time charts at the time of fax transmission by the same three kinds of methods as in FIG.

First, in FIG. 5, when a ringing signal is detected at the time of arrow (b-1), the signal is taken into the opening / closing switch control means (22) in the microcomputer (14), and the control means (2
2) issues an operation command to relay C and immediately turns on relay C for a predetermined time (t2). Then, since the bypass line (25) is closed, the relay A is turned on and the switch (18) composed of a transfer contact is switched to the modem side during the time t2.

Next, referring to FIG. 6 (a), it is the same as in FIG. 3 (a) that the other party responds by dialing by the telephone set (12) during the standby state.

Then, after the other party comes out, the operator sets the arrow (b-
When the transmission button (23) is pressed at the time of 2), the signal is taken into the control means (22), the relay C is immediately turned on for a predetermined time (t2), and the relay B is also turned on.

Then, the bypass line (25) is closed, the relay A is turned on during the time t2, and the switch (18) composed of the transfer contact is switched to the modem side.

Next, referring to FIG. 6B, the arrow (b
-3) Off-hook button on fax side (24)
When is pressed by the operator, the control means (22) immediately turns on the relay C, then the relay A is turned on, and the telephone line is switched to the modem side.

Then, dialing is enabled by turning on the relay C, and dialing is performed on the fax side. In this case as well, the dial pulse indicates "2".

Next, when the transmission button (23) is pressed by the operator at the time point of the arrow (b-4), the relay B is turned on, the relay C is turned off immediately thereafter, and the transmission is started at the time point of the arrow (b-5). To be done.

Next, the transmission method of FIG. 6 (c) will be described. In this method, the operator inputs the number of the destination dial during standby as in FIG. 3 (c), and the arrow (B-
When the operator presses the send button (23) at the time of 6),
Relay B and relay C immediately turn on, then relay A turns on and the telephone line switches to the modem side. At the same time, the dial tone is detected on the modem side to determine whether communication is possible. At the time of (b-7), the relay C
When turned on, a dial pulse of the dial number previously input by the operator is transmitted, and transmission is automatically started at the time of arrow (b-8).

Therefore, in the case of the second embodiment, the relay C can be switched from the telephone side to the modem side without disconnecting the telephone line even when the changeover switch (18) is a transfer contact by turning ON the relay C at a proper time.

Although the pulse dial circuit (15) is independently provided in the first and second embodiments, it is a so-called pulse dial circuit subordinate type in which the pulse dial circuit is subordinately provided. However, the present invention can be implemented.

 Next, it will be described as a third embodiment.

FIG. 7 is a circuit diagram of the third embodiment. In this case, the pulse dial circuit (15) is a bypass connected to the modem side from the telephone circuit (10) through the open / close switch (26) which is a transfer contact. It consists of a relay C in the middle of the line (27) and a resistor R1 forming a snubber circuit. (32) is relay C
It is an open / close switch that is opened and closed by.

Further, the switches corresponding to the changeover switch (18) of the above-mentioned embodiment are the changeover switches (28) and (29) which are simultaneously operated by the relay A.
Both 8) and (29) are transfer contacts, and the open / close switch (31) consisting of transfer contacts is also inserted in the connection line (30) extending from the ON side contact of the switch (29) to the modem side. This open / close switch (31)
And the open / close switch (26) are simultaneously operated by the relay B. In addition, in FIG. 7, the microcomputer (14)
, And the connection with each relay is omitted, of course, a microcomputer is connected to each relay, and various switches (23)
(24) is also connected.

Therefore, in the case of the third embodiment, the changeover switch (28) (2
Even if 9) is a transfer contact, the telephone line can be switched to the modem side without disconnecting the telephone line during switching.

Hereinafter, the transmission / reception operation in the third embodiment will be described in eighth and ninth embodiments.
It will be described with reference to the drawings.

FIG. 8 is a time chart at the time of fax reception, and FIGS. 9 (a), (b), and (c) are time charts at the time of fax transmission by the same three kinds of methods as those in FIGS. 3 and 6.

First, in FIG. 8, when a ringing signal is detected by the ringer detection circuit (16) at the time point of arrow (c-1), the signal is the open / close switch control means (2) in the microcomputer (14).
2), the control means (22) first turns on the relay C.
N, then relay B is turned on. Then, the bypass line (2
Since 7) is closed, immediately after the relay A is turned on, the switches (28) and (29) consisting of transfer contacts are switched to the modem side.

Next, referring to FIG. 9 (a), it is shown in FIG. 3 (a) and FIG. 6 (d) that the other party responds by dialing by the external telephone (12) during the standby state (shown in FIG. 7). The same as in (a), and then the operator selects the arrow (c-
When the send button (23) is pressed at the time of 2), the signal is taken into the control means (22), and immediately the relay C and then the relay B are turned on (the relay C is turned on from the standby state). It doesn't matter).

Then, since the bypass line (27) is closed, the relay A is subsequently turned on and the switches (28) (29) formed of transfer contacts are switched to the modem side.

Next, referring to FIG. 9 (b), in the case of this embodiment as well, the other party responds by dialing by the telephone set (12) during the standby state (the telephone line is connected to the telephone set). When the operator presses the off-hook button (24) at the time pointed by the arrow (c-3), the relay C is first turned on by the signal, and then the relay B is turned on for a predetermined time (t3).

During this predetermined time (t3), relay A turns ON,
The telephone line (10) is connected to the modem side, and relay C is turned on.
Dials the dial pulse "2".

Then, when the operator presses the send button (23) at the time of arrow (c-4), relay B is turned on and relay C is also turned on, so that transmission is started.

Next, the transmission method of FIG. 9C will be described.
In this method, as in the case of FIG. 3 (c), the operator inputs the number of the other party's dial during standby and the arrow (c-
When the operator presses the send button (23) at the time of 5),
First, relay C is turned on, then relay B is turned on to close the bypass line (27), and after a short delay, relay A is turned on to switch the telephone line to the modem side. It detects and determines whether communication is possible,
If possible, relay B turns off at the time of arrow (c-6).
Then, the dial pulse of the dial number previously input by the operator is transmitted, and the transmission is automatically started at the time of arrow (c-7).

Therefore, also in the case of the third embodiment, the relay B,
The bypass line (27) is closed by timely turning on the relay C, and even if the changeover switches (28) and (29) are both transfer contacts, the telephone line is switched from the telephone to the modem without disconnection.

It should be noted that the present invention can be applied not only to the fax machine as in the above embodiment, but also to various telephone terminal devices.

[Advantages of the Invention] As described above, according to the present invention, a switch composed of a transfer contact can be used as the changeover switch, the terminal device can be manufactured at low cost, and a transfer contact having a high withstand voltage is used. Therefore, it can be easily applied to a model that must comply with the foreign safety standards of the connection part without any special circuit arrangement.

[Brief description of drawings]

1 to 3 show a first embodiment according to the present invention.
Figure is a circuit diagram, Figure 2 is a time chart showing the operation of each relay when receiving a fax, and Figures 3 (a), (b) and (c) are time charts when different methods are used for fax transmission. FIGS. 4 to 6 show the second embodiment, FIGS. 7 to 9 show the third embodiment, FIGS. 4 and 7 are circuit diagrams, and FIGS. 5 and 8 are time charts for reception. Sixth,
FIG. 9 is a time chart during transmission, and FIG. 10 is a block diagram of a conventional device. (1) (10) …… telephone line, (2) …… circuit switching means,
(4) ... Modem, (12) ... Phone, (14) ... Microcomputer, (18) (28) (29) ... Changeover switch, (19)
(25) (27) …… Bypass line, (17) (20) (26) (3
2) …… Open / close switch, (22) …… Open / close switch control means.

Claims (1)

[Scope of utility model registration request] 1. A microcomputer for selectively connecting a telephone having a modem and a telephone to a telephone line via a changeover switch in the circuit changing means and controlling the circuit changing means. In the telephone line terminal device, a bypass line is provided for connecting the telephone line to the terminal side by bypassing the changeover switch, and an opening / closing switch is inserted in this bypass line, and the opening / closing switch is provided in the microcomputer. A telephone line terminal device, comprising: an opening / closing switch control means for controlling the switch and closing the opening / closing switch at least during a switching operation of the changeover switch to the modem side.