JPH08167947A - Communication equipment - Google Patents

Abstract

PURPOSE: To avoid the effect of a DC resistance onto a telephone set in the off-hook detection during transmission of a call signal and to eliminate uncomfortability to a talking party due to a pseudo call signal. CONSTITUTION: A call signal generating section 21 sending a call signal is provided in a DC power supply section 5 of the communication equipment and an off-hook during transmission of a call signal is sensed by an off-hook sensing circuit by sensing of an overcurrent of the call signal generating section 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to off-hook detection of a communication device provided with a pseudo call signal generating means in a DC power supply section.

[0002]

2. Description of the Related Art Conventionally, there is a facsimile apparatus having a function of activating an answering machine and ringing a ringing tone of the telephone.

In such a facsimile machine,
A ringing signal generating circuit is formed on the printed circuit board of the NCU or an independent printed circuit board, and a calling signal is sent from this circuit to activate the above-mentioned answering machine and ring the ringing tone of the telephone.

In the conventional calling signal generating circuit, in order to obtain a calling signal of high voltage (+ 24V to -150V),
A DC-DC converter system is adopted as the power supply voltage, and the boosted output obtained on the secondary side is controlled by a control signal from the main circuit side of the facsimile apparatus.

Further, the off-hook detection of the telephone during the sending of the pseudo call signal is detected by the line current detection means mounted on the NCU board.

[0006]

However, in the above-mentioned conventional example, in the off-hook detection during ringing of the telephone by the pseudo call signal, the signal from the line current detecting means on the NCU has a time constant due to the capacitor and the resistor. Because it was done in a form that had to be done, there were the following drawbacks.

(1) A current detection IC using a photocoupler, a current detection reed relay, or a hall element is used as the line current detection means. Therefore, considering the DC resistance of the telephone connected to the facsimile apparatus, the DC resistance of the line current detecting means cannot be ignored.

(2) Off-hook detection during ringing of the telephone by the pseudo-call signal was detected when the pseudo-call signal was interrupted, so the off-hook detection was delayed with respect to the off-hook of the telephone. Therefore, the pseudo-call was made after the telephone was off-hook. Since the pseudo call signal is input to the telephone until the signal transmission is stopped, the pseudo call sound is heard from the handset, which causes discomfort.

It is an object of the present invention to provide a communication device having an off-hook detecting means which has no influence on the direct current resistance of a telephone and which can eliminate discomfort to a caller due to a pseudo call signal.

[0010]

According to the present invention, ringing signal generating means for transmitting a ringing signal is provided in a DC power supply section of a communication device, and off-hook detection during the ringing signal transmission is detected by the ringing signal generating means. It is characterized in that it is performed using a current detection means.

Therefore, in the present invention, as in the conventional case,
Compared to the case where the off-hook detection is performed by the time constant signal from the line current detection means provided on the NCU, the direct current resistance of the telephone is not affected, and the caller is not affected by the pseudo call signal due to the delay in the off-hook detection. You can get rid of pleasure.

[0012]

1 is a block diagram of a facsimile apparatus according to an embodiment of the present invention.

The CPU 1 controls the entire facsimile apparatus according to a program stored in the ROM 2. The non-volatile memory 4 is the power source 5 of the facsimile machine.
It stores the data that should be saved even if is blocked.

The recording unit 6 is controlled by the CPU 1 and RA
The reading data is stored in the M3 and is printed out as a hard copy.
Under the control of the CPU 1, binarizes the data read using the CCD, and sequentially binarizes the binarized data.
It is sent to AM3.

The modem section 8 is composed of G3, G2, G1, FM modems and a clock generation circuit connected to these modems. Under the control of the CPU 1, a RAM is provided.
3 modulates the transmission data stored in No. 3 and outputs it to the telephone line 10 via the NCU unit 9. Further, the modem unit 8 receives the analog signal of the telephone line 10 from the NCU.
The data is introduced through the unit 9, demodulated, and binarized data is stored in the RAM 3.

Under the control of the CPU 1, the NCU unit 9 connects the telephone line to the modem unit 8 or the main telephone unit 11 and the answering machine 1.
6 is used for connection.

The power supply unit 5 is for generating the main power supply of the facsimile apparatus, and has an AC input (primary side).
Is configured to obtain a DC output. Also,
A power source for a calling signal for activating the answering machine 16 and ringing the main telephone section 11 is generated.

The call signal generator 21 outputs a pseudo call signal (Ci signal) to the answering machine 16, and is incorporated in the power supply unit 5. The Ci detection section 22 detects a ringing signal from the line 10.

FIG. 2 is a block diagram showing the configuration of the NCU unit 9.

The NCU unit 9 connects the line 10 to the telephone 11,
CM for selectively switching connection between the 16 side and the modem section 8 side
The L relay 17, the off-hook detection circuit 18 for detecting the response of the main telephone section 11, the off-hook detection circuit 19 for detecting the response of the answering machine 16, the answering machine 16 on the line 10 side and the ringing signal generating section 21 side. And a K relay 20 which is selectively switched and connected. Further, the call signal generation unit 21 of the power supply unit 5 is provided with an off-hook detection circuit 42 that detects overcurrent.

That is, in this embodiment, the answering machine 1
The off-hook detection when the line 6 is connected to the line is performed by the off-hook detection circuit 19, and the off-hook detection circuit 42 performs the off-hook detection while the pseudo call signal is being sent.

FIG. 3 is a flow chart showing the operation at the time of an incoming call in this embodiment.

First, the fact that the answering machine 16 is connected is registered in the nonvolatile memory 4 by a software switch or the like.

When there is an incoming call from the line 10 (S1), the CPU 1 switches the K relay 20 to the A side (call signal generating section 21 side) before the answering machine 16 answers (S2), Ci is detected by the Ci detector 22 (S3). Here, if it is not Ci, K
The relay 20 is switched to the B side (line 10 side) and the process returns (S13).

If S3 is Ci, CM
Switch the L relay 17 to the B side (modem 8 side) and switch to line 1.
0 is captured (S4), and it is determined whether it is an incoming call from a facsimile or an incoming call from a telephone (S5). If it is determined to be a facsimile here, the operation shifts to a facsimile communication operation (S14). On the contrary, if it is determined that the incoming call is from a telephone, the software switch is checked (S6). If the setting is that the answering machine 16 is not connected,
The operation shifts to the call operation by the main telephone unit 11 (S15). In the present embodiment, the facsimile communication and the telephone call by the main telephone unit 11 are omitted, and the starting operation of the answering machine 16 will be described.

That is, in S6, the answering machine 16
Is connected, the pseudo call signal generator 21 outputs the pseudo call signal of the frequency registered in advance in the non-volatile memory 4 a predetermined number of times or a predetermined time in order to activate the answering machine 16. S7).

Then, the response of the answering machine 16 is monitored by the off-hook circuit 42 using the overcurrent detection of the ringing signal generator 21 in the DC power supply, and if there is no response within the fixed time T, the next process is performed ( S9, S10). Also, if there is a response, set the CML relay 17 to the A side (answering machine 16
Side) (S11), and the answering process of the answering machine 16 is performed (S12).

FIG. 4 is a circuit diagram showing the configuration of the power supply unit 5.

The power supply unit 5 is an AC for inputting an AC voltage.
A plug 30, a power switch 31, a fuse 32,
Noise filter 33, rectifier circuit 34, smoothing circuit 35
And over voltage detection, over current protection, PW of switching power supply
A power supply control unit 36 including an M control and shutdown circuit, a transformer 37, a regulator unit 38 that outputs a DC voltage to each circuit, and a call that switches the voltage obtained from the transformer 37 to generate the pseudo call signal. The signal generator 21 and the main circuit of the facsimile machine (CPU
1) side, a photo coupler 40 for inputting a control signal for controlling the switching operation of the calling signal generating section 21 to change the frequency of the pseudo calling signal. That is, the main circuit side and the call signal generating section 21 are electrically separated by the photocoupler 40.

FIG. 5 is a timing chart showing the timing of the pseudo call signal.

This pseudo call signal is + 24V-GND-
It is a −150V square wave. The CPU 1 controls ON / OFF of the photocoupler 40 by pulse-controlling the output port of the control signal of the pseudo call signal in the parallel input / output unit (PIO) 12. Then, when the photocoupler 40 is on, −150V is output to the output end of the calling signal generator 21, and when the photocoupler 40 is off, + 24V is output.

Next, the off-hook detection of the answering machine 16 during communication will be described.

First, when the pseudo call signal is not transmitted, the pseudo call signal outputs + 24V. Also, the answering machine 16 during communication switches the K relay 20 to the A side. That is, a voltage of + 24V is applied to the answering machine 16.

Here, when the answering machine 16 is taken off-hook, +24 is output from the calling signal generator 21.
The V is terminated by the DC resistance of the answering machine 16, and at this time, the off-hook detection circuit 42 for detecting the overcurrent of the pseudo call signal generator 21 detects the overcurrent. Then, the off-hook detection can be performed by reading the output signal 41 of this overcurrent detection by the CPU 1.

On the other hand, the detection of the ringing signal of the usual answering machine is controlled so as to capture the line at the break of the ringing signal. Then, the conventional off-hook detection during transmission of the pseudo call signal is detected while the pseudo call signal is off, as shown in FIG.

However, if a person picks up the handset, the timing at which the handset is picked up does not necessarily mean that the handset is picked up while the pseudo call signal is off. Therefore, if you raise the handset while sending the pseudo call signal by the conventional control, you can hear the sound of the pseudo call signal from the handset.
This will make the caller uncomfortable.

Therefore, as in this embodiment, an off-hook detection circuit 42 for detecting the overcurrent of the ringing signal generator 21 is provided to speed up the response to the off-hook detection during the sending of the pseudo ringing signal.

FIG. 6 is a timing chart showing an example of off-hook detection during transmission of the pseudo call signal in this embodiment.

When the handset of the answering machine 16 is raised while the pseudo call signal is being sent, the pseudo call signal generating circuit is terminated by the DC resistance of the answering machine 16. Here, the direct current resistance of the telephone is defined by technical standards, from 50 ohms to 300 ohms.
Ohm.

That is, when the direct current resistance is terminated from 50 ohms to 300 ohms, the overcurrent detection circuit 42 of the ringing signal generator operates to output a signal. This is used as an off-hook signal and detected by the CPU 1 to stop the sending of the pseudo call signal.

By controlling in this way, it is possible to speed up the off-hook response during the sending of the pseudo call signal.

FIG. 8 is a block diagram showing the configuration of a key telephone system according to the second embodiment of the present invention.

In the figure, a dedicated telephone 105 is a four-line type button telephone connected to the main unit 101 via a telephone line 103 and a control line 104. Main device 10
Reference numeral 1 has a function of exchanging a plurality of dedicated telephones.

The main device interface 122 of the dedicated telephone 105 receives a control code such as a calling code from the main device 101, and also transmits a control code such as an off-hook code to the main device 101.

On the other hand, the dedicated telephone 105 is connected to the telephone line 10.
6 is connected to a two-wire type facsimile machine 107 via a relay unit 6 and serves as an adapter for connecting the facsimile machine 107 to the main apparatus 101.
117b connects the main apparatus 101 and the facsimile apparatus 107.

The DC voltage circuit 1 of the dedicated telephone 105
Reference numeral 23 includes a pseudo call signal generation circuit 119 and an off-hook detection circuit 132 which is transmitting the pseudo call signal.
Further, the dedicated telephone 105 includes a control circuit 121, a non-volatile memory 124, a hook switch 126, and an amplifier 12.
7, speaker 128, communication circuit 129, handset 13
0, a DC loop detection circuit 131, etc. are provided.

Next, FIG. 9 is a flow chart for explaining the operation of the dedicated telephone 105.

When the main unit interface 122 detects the call code (S61), the control circuit 121 generates a pseudo call signal built in the DC power supply 123 by using a square wave having a frequency registered in the non-volatile memory 124 as a control signal. Input to the section 119 to generate a ringing signal, and the call line 1
It is sent to the facsimile apparatus 107 via 06 (S6
2).

Then, the response of the facsimile apparatus 107 to the pseudo Ci is detected by the DC loop detection circuit 131 of the communication line 106. If the facsimile device 107 responds within a certain time (S63, S6).
4) The relay 117 is switched, the communication line 103 and the facsimile device 107 are connected (S66), and the facsimile communication is started (S67). If there is no response, the process moves to the next process (S65).

[0050]

As described above, according to the present invention,
Since the call signal generating means is built in the power supply unit of the device and off-hook detection is performed by using the output signal of the overcurrent detecting circuit of the call signal generating means, the line current detecting circuit affects the DC resistance as in the conventional case. The effect of not giving the information and the response time of the off-hook detection are quickened, and it is possible to prevent the caller from feeling uncomfortable.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an NCU unit in the above embodiment.

FIG. 3 is a flowchart showing an operation in the above embodiment.

FIG. 4 is a block diagram showing a configuration of a power supply unit in the above embodiment.

FIG. 5 is a timing chart showing an example of a pseudo call signal in the above embodiment.

FIG. 6 is a timing chart showing an example of off-hook detection during transmission of a pseudo call signal in the above embodiment.

FIG. 7 is a timing chart showing an example of conventional off-hook detection during transmission of a pseudo call signal.

FIG. 8 is a block diagram showing another embodiment of the present invention.

FIG. 9 is a flowchart explaining the operation of the other dedicated telephone set.

[Explanation of symbols]

 1 ... CPU, 2 ... ROM, 3 ... RAM, 5 ... Power supply section, 8 ... Modem section, 9 ... NCU section, 10 ... Telephone line, 11 ... Main telephone section, 16 ... Answering machine, 18, 19, 42, 132 ... off-hook detection circuit, 21 ... ringing signal generating section, 22 ... Ci detecting section, 40 ... photocoupler, 119 ... pseudo calling signal generating circuit, 123 ... DC voltage circuit.

Claims (4)

[Claims] 1. A calling signal generating means for sending a calling signal is provided in a DC power supply section of a communication device, and an electrical separating means for electrically separating a control signal for controlling the calling signal, and the calling signal generating means. And an overcurrent detecting means for detecting an overcurrent of the telephone, and the off-hook detection of the telephone is performed using the overcurrent detecting means. 2. The communication device according to claim 1, wherein the overcurrent detection of the ringing signal generation means is performed by a DC resistance load of a telephone. 3. The signal level of the ringing signal according to claim 1, wherein the signal level is configured to swing between a predetermined positive voltage value and a predetermined negative voltage value and cross 0 volt, and the ringing signal is not generated. The communication device is characterized in that a predetermined voltage value is output in the state. 4. The predetermined voltage value according to claim 1, wherein a predetermined voltage value is output when the ringing signal generating means does not generate a ringing signal, and an off-hook detection during communication does not generate the ringing signal. The communication device is characterized by performing overcurrent detection of.