JPH0983668A - Communication terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication terminal equipment without an automatic incoming mistake and a malfunction by erroneously discriminating on-hook/ off-hook in the case of receiving a calling signal and of originating a dial pulse. SOLUTION: A line current detecting means A for detecting presence or absence of line current which is permitted to flow in a telephone line L is provided, a monitoring timer 8 is started when the line current detecting means A detects line current which exceeds a prescribed value Ith, presence or absence of line current is discriminated again after a prescribed monitoring time T elapses and a basic operation for judging the off-hook of telephone sets T1 and T2, etc., is executed. In the meantime, whenever the line current detecting means A detects the change of line current which exceeds the prescribed value, the monitoring timer 8 is reset and started again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal device such as a facsimile device equipped with an attached telephone, and more particularly to a communication terminal device such as a telephone connected to a telephone line, which can accurately determine on-hook or off-hook.

[0002]

2. Description of the Related Art In a communication terminal device of this type, for example, a facsimile device to which an attached telephone is connected, not only the facsimile communication but also the call by the attached telephone is possible. In such a facsimile machine, when a ringing signal transmitted from the telephone exchange is received a predetermined number of times, the telephone line is closed to automatically receive an incoming call, and thereafter, when a CNG signal indicating the facsimile communication is received from the other party. , Facsimile reception is started according to the facsimile communication procedure, but CNG
When it does not receive a signal, it rings the pseudo-bell and calls the attached telephone, so if you pick up the handset, you can talk as it is.

By the way, the pick-up of a telephone handset in such a facsimile apparatus is judged by an off-hook detecting means provided with a photocoupler, and a line current exceeding a predetermined value (Ith) continuously flows for a predetermined time on a telephone line. When the photocoupler remains on, it is considered off-hook. This photo coupler is L
It is composed of an ED and a phototransistor, and when the line current flowing in the telephone line when the telephone is off-hook exceeds a predetermined value (Ith), the LED is caused to emit light, and the phototransistor is turned on accordingly. Is detecting the start and continuation of.

Further, this photocoupler is turned on in principle when a line current exceeding a predetermined value (Ith) flows in the telephone line except when it is off-hook. Therefore, for example, a ringing signal (CI) from an outside line is received. Also, it is turned on during a pause time when the telephone is held in an off-hook state and a dial pulse (DP) is transmitted. Therefore, since it is not possible to determine off-hook only by turning on the photocoupler, it is customary to use a monitoring timer to make an off-hook determination only when the on-state of the photocoupler continues for a predetermined time or longer.

For example, after starting the monitoring timer when the photocoupler is turned on, a predetermined monitoring time (for example, 4
(00 msec), when the photo coupler is turned on and off again when it is turned on, it is determined to be off hook,
If it is off, it is judged to be on-hook.

[0006]

However, in the conventional communication terminal device which detects the off-hook of the telephone by using the monitoring timer in this way, the following problems occur. That is, when the call signal CI is received from the telephone line while the telephone is in the on-hook state,
As shown in (a) to (e), if the photocoupler is turned on for some reason, the monitoring timer is activated and enters the set state, and the monitoring timer has passed the predetermined monitoring time T. If the photocoupler is turned on again by the call signal at this point, the communication terminal device (signal processing unit) determines that it is off-hook.

When such an off-hook determination is made, even if the calling signal CI is received thereafter, the incoming call is not automatically received and the facsimile reception cannot be performed. Further, when the telephone is set to the off-hook state and the dial pulse DP is transmitted, as shown in (a) to (e) of FIG. 6, the photo coupler is turned on and the monitoring timer is started at the time of off-hook. After that, if the time when the predetermined monitoring time T has passed and the time when the line current is cut off by the dial pulse DP overlap, the photocoupler is turned off. Has made an on-hook decision, and in this case,
Since the photo coupler of the calling signal detecting means is also turned on and off by the dial pulse DP, the cycle (10 pps, 20 pps) of the dial pulse DP and the frequency (16 Hz) of the calling signal CI are close to each other. There is a problem that the dial pulse DP is erroneously determined as the calling signal CI and an automatic call is received.

The present invention has been proposed in view of the above circumstances, and an object of the present invention is to provide a communication terminal device which does not make an erroneous determination of on-hook or off-hook by a calling signal or dial pulse.

[0009]

The present invention according to claim 1, which is proposed to achieve the above object, provides a line current detecting means for detecting the presence or absence of a line current flowing through a telephone line. When the detection means detects a line current exceeding a predetermined value, a monitoring timer is started, and after a predetermined monitoring time elapses, the presence / absence of a line current is determined again to perform a basic operation of determining off-hook of a telephone or the like. The monitoring timer is reset and restarted each time the change in line current exceeds a predetermined value.

In this communication terminal device, a monitoring timer is started each time the change in the line current of the telephone line exceeds a predetermined value, and thereafter, the line current detecting means is monitored when a predetermined monitoring time elapses. It is determined whether or not a current exceeding a predetermined value is flowing, and if it is flowing, it is determined to be off-hook at that time, but if not, it is determined to be on-hook.

Therefore, according to such a configuration, when the telephone is actually off-hook, the line current exceeding the predetermined value Ith is detected during that time, so that the monitoring is started after the monitoring timer is activated. When the time T has elapsed, it is determined to be on-hook (see (a) to (e) of FIG. 2). Also, when the phone is on-hook,
When the line current detecting means detects the line current exceeding the predetermined value by the input call signal CI, the operation of resetting and restarting the monitoring timer is repeated. During this time, the set state of the monitoring timer passes the monitoring time T. Since it is not held until, the monitoring time is not judged to be on-hook or off-hook, and the monitoring timer T is reset and restarted after the input of the last call signal CI is completed, and then the monitoring time T elapses for the first time. At this point, the on-hook state is correctly determined (see (a) to (e) in FIG. 3).

Further, the telephone is set off-hook,
When the dial pulse DP is transmitted, the monitoring timer is reset and restarted when the telephone is taken off-hook, and thereafter the line current flows at each pause time when the dial pulse DP is transmitted, so the monitoring timer is reset. Repeat the operation to restart. Therefore, when the dial pulse DP is transmitted, the monitoring timer does not measure the monitoring time T, but the monitoring time T is measured after the last dial pulse DP is output, and off-hook is determined at that time. The call signal CI will not be erroneously determined and an automatic incoming call will not be received ((a) to FIG. 4).
(E)).

According to the present invention as described above, the signal processing unit sets the predetermined monitoring time T of the monitoring timer to the time when the line current flows when the ringing signal CI is input or when the dial pulse DP is transmitted and the line current due to off-hook. The time during which the current flows can be sufficiently discriminated, for example, about 400 msec. According to a second aspect of the present invention, in the first aspect, the line current detecting means is provided with a photocoupler which is turned on and off each time a change in the line current exceeds a predetermined value.

According to a third aspect of the present invention, the monitoring time by the monitoring timer of the first aspect is set to a time longer than the duration of the ringing signal from the outside line or the pause time at the time of dial pulse transmission. Therefore, at the time when the ringing signal is being input (the duration of the ringing signal) or at the time when the line is not interrupted during dial pulse transmission, the signal processing unit determines whether there is line current in the line current detecting means. I try not to.

The duration of the ringing signal (16 Hz) is about 30 msec and the dial pulse (the cycle is 100 mse).
c or 200 msec) rest time is about 60 ms
Since it is ec to 120 msec, the monitoring time of the monitoring timer is set to a longer time, for example, 400 ms. In addition, the line current detection means is set at 1 second intervals from the telephone exchange.
When receiving a call signal of 16 Hz transmitted every second, it does not necessarily detect a line current exceeding a predetermined value in response to a positive half wave, and the line current may be affected by the telephone exchange or telephone line. There is a difference in the length of time for detecting. For this reason, a current exceeding a predetermined value may be detected during 1 second while the ringing signal is transmitted. In this case, the monitoring time of the monitoring timer is set to 1
You may set it to more than a second. However, since this rarely occurs, and a call signal may be input or a dial pulse may be transmitted immediately after the change of on-hook or off-hook, the monitoring time may be set to about 400 msec as described above. desirable.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit configuration diagram showing an example in which the communication terminal device according to the present invention is embodied in a facsimile device F. The facsimile apparatus F includes a line controller 1, a modem 2 for executing facsimile communication,
A signal processing unit 3 including a CPU, a ROM 4, and an R
An AM 5, an image reading unit 6, a print output unit 7, a monitoring timer 8 for monitoring a line current detecting means A described later, a key operation unit 9 such as a ten-key pad, and a display unit 10 such as a liquid crystal screen. There is.

The line control unit 1 is connected to an auxiliary telephone T1 and a slave telephone T2 via a cable (not shown) to control switching of the telephone line L. The line control unit 1 also includes a CML relay 11 for selectively connecting the telephone line L to the modem 2 and the call signal detection circuit 13.
And a TEL relay 14 for switching and connecting the telephones T1 and T2 to the telephone line L and the ringing voltage generation circuit 18, and off-hook detection circuits 16 and 17 for detecting off-hook of the telephones T1 and T2. .

The line current detecting means A is composed of off-hook detecting circuits 16 and 17, each of which has LE.
D16a, 17a and phototransistors 16b, 17b
It is equipped with a photo coupler consisting of. In each of the line current detecting means A as described above, a predetermined value Ith is applied to the telephone line L.
When a line current that exceeds the threshold current flows, the LEDs 16a and 17a emit light and turn on the phototransistors 16b and 17b. Therefore, the signal processing unit 3 detects whether the phototransistors 16b and 17b are on or off at this time, and will be described later. Off-hook is determined according to the procedure.

The basic operation of the facsimile apparatus F will be described below. 16 via telephone line L from telephone exchange
When the call signal CI of Hz is transmitted, the call signal CI is detected by the call signal detection circuit 13 (photocoupler) including the LED 13a and the phototransistor 13b. When the signal processing unit 3 detects the calling signal CI a predetermined number of times (for example, twice), the CML relay 11 is switched from the contact a side to the b side, and the telephone line L is connected to the modem 2 via the transformer 12.

At the same time when the telephone line L is closed in this manner, the TEL relay 14 is also switched from the contact a side to the side b, and the telephones T1 and T2 are connected to the telephone line L and the transformer 1.
From the connection with the modem 2 via 5, the ringing voltage generation circuit 1
The connection is switched to 8, and power is supplied so that the off-hook detection circuits 16 and 17 can detect the off-hook of the telephones T1 and T2.

In the signal processing unit 3, the CN is connected via the modem 2.
When a communication procedure signal such as a G signal is detected, facsimile communication is performed according to the facsimile communication procedure.
When the NG signal is not detected, the ringing voltage generation circuit 18
To generate a pseudo bell signal to ring each of the telephones T1 and T2. When one of the telephones T1 and T2 is off-hook in response to this ringing, the CML relay 11 and the TEL relay 14 are switched from the contact b side to the a side, and a call with the partner telephone becomes possible.

Incidentally, in a state where the calling signal CI is not detected,
When one of the telephones T1 and T2 is off-hook, the CML relay 11 and the TEL relay 14 have a contact a.
Is kept closed, and when the other party's telephone is called by a dial operation or the like after a lapse of a predetermined time (after determination of off-hook), a call becomes possible. Telephone T by signal processing unit 3
The off-hook detection of 1 and T2 is performed by the off-hook detection circuits 16 and 17 forming the line current detection means A.
Specifically, a line current that exceeds a predetermined value Ith flows through the telephone line L, and each time the phototransistors 16b and 17b are turned on / off, the monitoring timer 8 is reset and then restarted. The preset monitoring time T
At the time of passing, the phototransistors 16b, 17
On / off of b is detected, and if the phototransistors 16b and 17b are on at that time, it is determined to be off-hook, and if it is off, it is determined to be on-hook.

Therefore, according to such a configuration, if the telephones T1 and T2 are held in the off-hook state, as shown in FIGS. 2 (a) to 2 (e), the off-hook detection circuits 16 and 17 are provided. The monitoring timer 8 is reset by and is restarted to maintain the set state by the monitoring time T
Since the transistors 16b and 17b remain on after the passage of, it is determined to be off-hook.

However, as shown in FIGS. 3A to 3E, when the calling signal CI is input, the photocouplers of the off-hook detection circuits 16 and 17 are driven by the calling signal CI for some reason. , Phototransistors 16b and 17
When b is repeatedly turned on and off, the monitoring timer 8 is reset until the monitoring time T elapses and then restarts again. Therefore, the set state of the monitoring timer 8 passes the monitoring time T. However, the monitoring timer 8 does not exceed the monitoring time T after being reset and restarted by the input of the final call signal CI. Therefore, when the monitoring time T elapses, it is possible to correctly determine the on-hook without making an erroneous determination as the off-hook.

Further, as shown in FIGS. 4A to 4E, when the telephone is off-hook and the dial pulse DP is transmitted, the off-hook detection circuit 1 is generated at the time of off-hook.
Since the photo couplers 6 and 17 are driven, the monitoring timer 8
Is reset and then restarted, and thereafter the off-hook detection circuit 1
Since the photocouplers 6 and 17 are repeatedly turned on and off, the monitoring timer 8 is reset until the monitoring time T elapses and then restarts again. Therefore, the monitoring timer 8 does not elapse the monitoring time T while transmitting the dial pulse DP, and is reset after the line current is cut off by the last dial pulse DP,
The monitoring time T elapses only after being restarted. At this point, the off-hook detection circuits 16 and 17 correctly detect the off-hook state, so that the dial pulse DP will not be erroneously received as the call signal CI automatically.

2 to 4 are time charts showing the basic operation of the communication terminal device of the present invention. FIGS. 2 (a) to 2 (e) are the basic operations when the telephone is off-hook. 3 (a) to 3 (e) are basic operations when the line current detecting means A is operated at the time of receiving the call signal CI, and FIGS. 4 (a) to 4 (h) are dial pulse DP.
The respective time charts of the basic operations at the time of making a call are shown.

Here, the predetermined monitoring time T is the calling signal C.
It is necessary to set the time (for example, 400 ms) longer than the duration t1 of I (see (a) of FIG. 3) or the pause time t2 of the dial pulse (see (a) of FIG. 4) (T> t1, T> t2).

[0028]

As can be understood from the above description, according to the communication terminal device of the present invention as set forth in claim 1, the line current detecting means changes the line current flowing through the telephone line up and down by a predetermined value. The monitoring timer is reset and restarted each time it exceeds, and after the monitoring timer has started, after a predetermined monitoring time has elapsed, the presence or absence of a line current is determined to determine whether it is off-hook or on-hook. Therefore, when receiving a ringing signal or sending a dial pulse, the monitoring timer repeats the operation of being reset and restarted before the monitoring time elapses.
Since the monitoring operation is disabled, it is possible to prevent the off-hook or on-hook from being erroneously determined when a ringing signal or dial pulse is transmitted from an outside line.

Therefore, when the call signal from the outside line is received, it is determined that the call is off-hook, so that the automatic incoming call cannot be performed, or the automatic incoming call is not accidentally made when the dial pulse is transmitted in the off-hook state. Claim 2
According to the communication terminal device of the present invention described in (1), since the line current detecting means has a configuration including a photocoupler, it is realized by simply changing the program in the conventional hardware configuration using the photocoupler and the monitoring timer. I can.

According to the third aspect of the communication terminal device of the present invention, the time of the line current that temporarily flows through the telephone line and exceeds the predetermined value is the duration of the ringing signal or the pause time during dial pulse transmission. Off-hook, if shorter
Never mistakenly judge on-hook.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration in which a communication terminal device according to the present invention is applied to a facsimile device.

2 (a) to (e) are time charts for explaining an example of the basic operation of the communication terminal device according to the present invention when the telephone is off-hook.

3 (a) to 3 (e) are time charts for explaining an example of the basic operation of the communication terminal device according to the present invention when receiving a call signal.

4 (a) to (e) are time charts for explaining an example of the basic operation of the communication terminal device according to the present invention at the time of dial pulse transmission.

5 (a) to (e) are time charts for explaining an example of the basic operation of the conventional communication terminal device when receiving a call signal.

6A to 6E are time charts for explaining an example of the basic operation of the conventional communication terminal device at the time of dial pulse transmission.

[Explanation of symbols]

F ... Communication terminal device (facsimile device) according to the present invention A ... Line current detecting means T ... Predetermined monitoring time t1 ... Duration of ringing signal t2 ... Pause time of dial pulse 1・ ・ ・ Line control unit 2 ・ ・ ・ Modem 3 ・ ・ ・ Signal processing unit 8 ・ ・ ・ Monitoring timer 11 ・ ・ ・ CML relay 13 ・ ・ ・ Call signal detection circuit 14 ・ ・ ・ TEL relay 16, 17 ・ ・ ・Off-hook detection circuit 13a, 16a, 17a ... LED 13b, 16b, 17b ... Phototransistor L ... Telephone line T1 ... Attached telephone T2 ... Sub-phone

Claims (3)

[Claims] 1. A line current detecting means for detecting the presence / absence of a line current flowing through a telephone line is provided. When the line current detecting means detects a line current exceeding a predetermined value, a monitoring timer is started to perform a predetermined monitoring. After the lapse of time, the basic operation of determining the presence or absence of line current again to determine the off-hook state of a telephone or the like is performed, while the monitoring timer is reset and restarted whenever the change in line current exceeds a predetermined value. Communication terminal equipment. 2. The communication terminal device according to claim 1, wherein said line current detecting means is provided with a photo coupler which is turned on and off each time a change in line current exceeds a predetermined value. 3. The monitoring time of the monitoring timer is set to a time longer than a duration of a ringing signal from an outside line or a dwell time at the time of dial pulse transmission.
A communication terminal device according to claim 1.