JP2004064645A - Communication system - Google Patents

Abstract

An object of the present invention is to provide a communication device to which a telephone can be connected, which can reduce the cost of the communication device and can solve the howling phenomenon that occurs at that time.
Communication means for connecting to a telephone line for communication, connection means for connecting a telephone to the telephone line via the communication means, and communication means for capturing the telephone line. A hook state detecting means for connecting the telephone to the telephone line and detecting a hook state of the telephone based on a line current. This is a communication device that prevents howling by turning off the speaker.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication device to which a telephone can be connected.
[0002]
[Prior art]
FIG. 6 is a circuit diagram showing a conventional communication device 200.
[0003]
The conventional communication device 200 has a facsimile device FS2 and a telephone set 25. The facsimile device FS2 is connectable to the telephone set 25 and has a dedicated DC power supply 18 for detecting off-hook of the telephone set 25.
[0004]
The DC power supply 18 disconnects the telephone 25 from the line while the facsimile device FS2 is capturing the line or while the facsimile device FS2 is in a state where the telephone 25 is in a silent state. In this state, the off-hook of the telephone set 25 is detected.
[0005]
Next, the operation of the above conventional example will be described.
[0006]
In the normal standby state, the CML relay 12 and the H relay 16 are turned off, and the telephone set 25 connected to T1 / T2 is connected to the line connected to L1 / L2. Therefore, when the telephone 25 is off-hook, current flows from the line, and the off-hook can be detected by the output of the HOOK detector 15.
[0007]
However, when the CML relay 12 is turned on while the line is being captured, a signal from the line is sent to the inside of the facsimile apparatus FS2 through the transformer 13, and the telephone 25 is suppressed from ringing by the ringing signal while waiting for the silent setting. Therefore, the H relay 16 is turned on, which disconnects the telephone set 25 from the line, and makes it impossible to detect the hook by the current from the line.
[0008]
Therefore, in the above conventional example, a DC power supply 18 is provided for hook detection, the H relay 16 is connected to the ON side, and hook detection is performed based on a current from the DC power supply 18.
[0009]
When the telephone 25 is off-hook and dialing is performed from the facsimile apparatus FS2, in the above-described conventional example, the H relay 16 is turned on, the telephone 25 is connected to a DC power source, and the CML is detected while the hook of the telephone 25 can be detected. By turning on the relay 12 and extracting a signal on the line from the TX / RX line, a line monitor sound is generated by the speaker 21 via the speaker controller 24.
[0010]
[Problems to be solved by the invention]
In the above-mentioned conventional example, the DC power supply 18 is usually incorporated in a power supply unit. However, the DC power supply 18 itself has a problem that the cost of the power supply unit is increased. There is a problem that the cost is greatly increased due to the cables and connectors for connecting the power supply 18 and the man-hours required for the connection.
[0011]
An object of the present invention is to provide a communication device that can reduce the cost of the communication device and can solve the howling phenomenon that occurs at that time.
[0012]
[Means for Solving the Problems]
The present invention relates to a communication unit that connects to a telephone line to perform communication, a connection unit that connects a telephone to the telephone line via the communication unit, and a state in which the communication unit captures the telephone line. A hook state detecting means for connecting the telephone to the telephone line and detecting a hook state of the telephone based on a line current. This is a communication device that prevents howling by turning off the speaker.
[0013]
Embodiments and Examples of the Invention
FIG. 1 is a circuit diagram showing a communication device 100 according to one embodiment of the present invention.
[0014]
The communication device 100 includes a facsimile device FS1 and a telephone 23.
[0015]
The facsimile apparatus FS1 includes a diode bridge 1, a P relay 2, a CML relay 3, a transformer 4, a two-wire to four-wire conversion circuit 5, a hook detector 6, an H relay 7, and a hook detector 8. , H detection relay 9, CI detection circuit 10, speaker 20, and speaker controller 22.
[0016]
T1 / T2 is a terminal for connecting a telephone, and L1 / L2 is a terminal for connecting a telephone line.
[0017]
The diode bridge 1 is a diode bridge that rectifies a signal from the telephone line connected to L1 / L2 and connects to the H detection relay 9, and converts the signal from the line into DC. Even if the call is made, the telephone does not ring due to the calling signal.
[0018]
The P relay 2 is a P relay for transmitting a dial pulse, and the CML relay 3 is a relay for capturing or disconnecting a line.
[0019]
The transformer 4 is a transformer for generating a DC loop, capturing a line, and capturing an AC component.
[0020]
The 2-wire to 4-wire conversion circuit 5 is a circuit for converting a signal received through a transformer to a 2-wire to 4-wire conversion, and sends and receives a signal between a modem (not shown) in the facsimile apparatus FS1 and a line.
[0021]
The hook detector 6 is a hook detector that detects a hook when the CML relay 3 and the H relay 7 are off.
[0022]
The H relay 7 is a relay that switches between a telephone connected to T1 / T2 and a line via the CML relay 3 or a line via the H detection relay 9.
[0023]
The hook detector 8 is a hook detector that detects a hook when the H relay 7 and the H detection relay 9 are on.
[0024]
The H detection relay 9 is a relay that connects a signal that has passed through the diode bridge 1 to the H relay 7.
[0025]
The CI detection circuit 10 is a detection circuit that detects a call signal from a line.
[0026]
The speaker 20 is a speaker that extracts a TX / RX line signal and emits a line monitor sound.
[0027]
The speaker controller 22 controls on / off of the speaker 20.
[0028]
The telephone 23 is a telephone connected to the T1 / T2 terminal.
[0029]
Next, the operation of the above embodiment will be described.
[0030]
In the above-described embodiment, hook detection is performed by the current from the line even while the line is being captured or in a standby state with no sound set, and the signal from the line is rectified through the diode bridge 1, Since it is DC, the telephone connected to T1 / T2 does not ring even if a call signal comes. Therefore, even in a standby state in which no sound is set, hook detection can be performed by the current from the line.
[0031]
Also, during communication or dialing, the influence of the telephone becomes a problem, so the H detection relay is turned off and the influence is cut, so that hook detection cannot be performed.
[0032]
FIG. 2 is a block diagram showing the communication device 100.
[0033]
The CPU 101 is a system control unit, and controls the entire apparatus. The ROM 102 stores a control program for the CPU. The RAM 103 is configured by an SRAM or the like, and stores program control variables and the like. The transmission destination telephone number and e-mail address registered by the operator, various setting values, device management data, and various work buffers are also stored in the RAM 103.
[0034]
The storage memory 104 is composed of a DRAM or the like, and stores image data. The external display unit 105 notifies the user of the display using an LCD, an LED, or the like. The speaker 20 has a built-in speaker control unit for notifying and warning a user by voice, monitoring a signal sound being transmitted and received through the PSTN line 112, and turning on and off the speaker 20.
[0035]
The MODEM 107 modulates and demodulates a facsimile transmission / reception signal and generates a selection signal (tone dialer). The pulse dial is generated by the P relay 2.
[0036]
NCU 100 transmits a selection signal (dial pulse or tone dialer) to PSTN line (analog public line network) 112, and also performs an automatic call receiving operation by detecting a call signal. The NCU 100 connects a telephone set 23 (or a handset of the telephone set 23) from the T1 / T2 terminal shown in FIG. The NCU 100 turns on / off various relays according to an instruction from the CPU 101 in response to the detected call signal and hook detection signal.
[0037]
The relay control unit 108 controls various relays shown in FIG.
[0038]
The image processing unit 114 performs a correction process on the read image data, and outputs high-definition image data.
[0039]
The scanner 115 includes a CS image sensor, a document transport mechanism, and the like, optically reads a document, and converts the document into electrical image data. The operation unit 116 includes a keyboard, a touch panel, and the like, and is used by an operator to perform various input operations. Here, in addition to the operation unit for dialing, it is possible to set a ringing standby state, a non-ringing standby state, and an F / T switching mode, an automatic reception mode, a manual reception mode, and the like as an incoming call mode.
[0040]
The printer formatter 118 analyzes a printer description language and converts it into image data when printing file data from an external device such as a PC or a workstation. The printer 119 is a device that records a received image and file data on recording paper.
[0041]
Next, how to use the communication device 100 will be briefly described.
[0042]
The following operation is performed by the CPU 101 executing a program stored in the ROM 102. The CPU 101 controls on / off of the CML relay 3, the H relay 7, the H detection relay 9, and the P relay 2 via the relay control unit 108.
[0043]
Next, how to use the circuit in each state will be described.
[0044]
In the standby state of the sound setting, the CML relay 3 and the H relay 7 are off. Therefore, the line connected to L1 / L2 is directly connected to the telephone set 23 connected to T1 / T2. When a call signal is received from the line, the telephone set 23 connected to T1 / T2 rings and the telephone set 23 If you go off-hook, you can talk. The hook state of the telephone 23 is monitored by the HOOK detector 6.
[0045]
In the non-sound standby state, the CML relay 3 is off, but the H relay 7 is on. The telephone set 23 connected to T1 / T2 is connected to the line via the diode bridge 1 and the H detection relay 9. Therefore, the telephone 23 does not ring due to a call signal from the line, but the HOOK detector 8 can know the hook state. When the user goes off-hook on the telephone 23, a control unit (not shown) turns off the H relay 7 and connects the line to the telephone 23.
[0046]
When a line is used for communication or the like, the CML relay 3 is on, seizes the line, the H relay 7 is on, and the telephone 23 is disconnected from the line, but the H detection relay 9 is off. Also, power supply via the diode bridge 1 is not performed. Therefore, the influence of the telephone 23 is completely eliminated, but the hook state of the telephone 23 cannot be known.
[0047]
At this time, the signal of the TX / RX line is extracted, and the speaker 20 emits a line monitor sound. However, the howling phenomenon does not occur because the telephone 23 is disconnected from the line.
[0048]
In the case of FAX / TEL switching, in a line capturing state for FAX / TEL switching in which the influence from the line can be ignored, the H detection relay 9 can be turned on to detect a hook.
[0049]
Finally, in the case where the line is seized but no communication is performed, the CML relay 3 is on, seizes the line, and both the H relay 7 and the H detection relay 9 are on, The telephone 23 is supplied with power via the diode bridge 1. Therefore, the hook can be detected, but the effect of the telephone 23 on the line is not zero. In this state, except when the dial signal is transmitted, the H detection relay 9 is turned off and the telephone 23 is disconnected from the line, so that the howling phenomenon does not occur. These are mainly used for FAX / TEL switching. When an off-hook is detected, the CML relay 3 and the H relay 7 are turned off, and a call is made. When a CNG signal is detected, the H detection relay 9 is turned off. Then, move to communication.
[0050]
In the above operation, when the telephone 23 is off-hook and dialing is performed from the FAX side, a state occurs in which all the relays of the CML relay 3, the H relay 7, and the H detection relay 9 are turned on.
[0051]
At this time, depending on the positional relationship between the telephone 23 and the speaker 20 connected to the T1 / T2 terminal, the microphone of the telephone 23 picks up background noise, and the H relay 7, the H detection relay 9, the diode bridge 1, the CML relay 3, through the transformer 4 and the 2-4 wire converter 5, sound is output from the speaker 20. In this process, the background noise signal is amplified to a considerable extent in the telephone set 23 and the RX line. The amplified background noise generated by the speaker 20 is input again from the microphone of the telephone 23, and a howling phenomenon occurs in this repetition. Then, the howling phenomenon makes the user uncomfortable, and further, the amplified signal damages an electric circuit in a signal path, leading to a failure of the facsimile machine.
[0052]
Next, the off-hook dial operation of the facsimile machine FS1 and the control operation of the speaker 20 for preventing the howling phenomenon will be described.
[0053]
FIG. 3 is a flowchart showing the off-hook dial operation of the facsimile machine FS1 and the control operation of the speaker 20 for preventing the howling phenomenon.
[0054]
At the start of off-hook dialing, in S301, the relays are initialized, the CML relay 3 is on, the line is seized, the P relay 2 is off, the signal can pass, and the H relay 7 is on. Is turned on, the telephone 23 is disconnected from the line, the H detection relay 9 is turned off, the connection via the diode bridge 1 is not performed, and the speaker controller 22 is switched to the state where the speaker 20 can monitor the line. Is set.
[0055]
In S302, one-digit dialing is performed. Since the dial transmission method is publicly known and will not be described in detail, in the case of DTMF, a DTMF signal is transmitted from the modem 107, and in the case of a pulse, the P relay 2 is turned on and then the CML relay 3 is turned off. Then, after eliminating the effect of the transformer 4, the P relay 2 is turned off / on to generate a pulse. After generating a desired number of pulses, the CML relay 3 is turned on, the P relay 2 is turned off, and the transmission of one digit of dial is completed.
[0056]
FIG. 4 is a timing chart in the above embodiment.
[0057]
In S303, it is checked whether or not dialing of all digits has been completed. If the dialing of all digits has been completed, the dialing process ends, and if there is a digit for which dialing has not been completed, the process proceeds to step S304.
[0058]
In S304, it is checked whether or not the dial is an off-hook dial. In other than the off-hook dial, by pressing a hook key or a stop key (not shown) of the facsimile apparatus FS1, it is possible to detect abandonment of dial transmission in the middle of dialing. Since the hook detection is unnecessary and the control of the speaker 20 is not necessary, the process waits for the inter-digit pause time in S306, returns to S302, and continues dialing.
[0059]
If it is an off-hook dial in S304, it is checked in step S305 whether a communication start instruction has been received. In the present embodiment, it is checked whether or not a communication start instruction has been received, depending on whether or not the user has pressed the start key. If an instruction to start communication has been received, the subsequent hook detection is not executed. Therefore, in S306, after waiting for the inter-digit pause time, the flow returns to S302 to continue dialing.
[0060]
If an instruction to start communication has not been received (S305), in step S307, the H detection relay 9 is turned on to enable hook detection, and the speaker 20 is turned off so that a howling phenomenon does not occur. After waiting for the inter-digit pause time (S308), the HOOK1 signal is checked in S309. If it is in the off-hook state, the H detection relay 9 is turned off in S310 and the speaker 20 is turned on. Then, the process returns to S302 and dialing is continued.
[0061]
If it is in the on-hook state (S309), it waits for an arbitrary time in S311. In this embodiment, the wait time is set to 500 ms. Then, in S312, it is checked whether the on-hook is determined. In this embodiment, the hook is determined in a task different from the dial, and the dial execution task is controlled with reference to the determination result. A method for determining a hook will be described later.
[0062]
If the on-hook has been determined (S312), the dialing process is terminated. If the on-hook has not been determined (S312), the process returns to S309 and checks the HOOK1 signal again. Thereafter, the loop of steps S309 to S312 is repeated until the on-hook is determined or the HOOK1 signal returns to the off-hook state.
[0063]
In the above embodiment, the speaker 20 is turned off between the dial digits, but is not limited to this. For example, after the off-hook dial is determined (S304), the speaker 20 may be turned off, and the processing after step S305 may be executed. In this case, the operation of turning on the speaker 20 (S310) may not be performed.
[0064]
Next, the hook determination process in the above embodiment and the speaker 20 control process during this process will be described.
[0065]
FIG. 5 is a flowchart showing the hook determination process in the above embodiment and the control process of the speaker 20 during this process.
[0066]
The processing shown in FIG. 5 is executed by a periodic task having a 1 mS cycle, and it is assumed that variables are initialized before the processing is started. The variables used in this embodiment are Result for storing a hook result, an on-timer for certifying on-hook, and an off-timer for certifying off-hook. Result is initialized to on, the on timer is initialized to 2200, and the off timer is initialized to 2200. Is initialized to 200. In the present embodiment, since this processing is performed at a cycle of 1 mS, on-hook recognition is performed at 2.2 S and off-hook recognition is performed at 0.2 S.
[0067]
First, in S401, it is checked whether the H relay 7 is on. Here, if it is on, it is checked whether the relay 9 is on (S402). If the H detection relay is on, power is supplied to the telephone set 23 from the line via the diode bridge 1 → the H detection relay 9 → the H relay 7, so that the HOOK detector 8 can detect the hook. Therefore, HOOK1 is read (S404), and the process proceeds to S406.
[0068]
If the H detection relay 9 is off (S402), the hook cannot be detected, and the hook determination process ends. At this time, since the variable such as the hook result is not updated, the result when the hook detection is possible is taken over.
[0069]
If the H relay 7 is off (S401), it is checked in S403 whether the CML relay 3 is off. If the CML relay 3 is off, power is supplied to the telephone set 23 from the line via the CML relay 3 → the H relay 7, so that the HOOK detector 6 can detect the power. Therefore, in S405, HOOK2 is read, and the process proceeds to S406.
[0070]
If the CML is on (S403), the hook cannot be detected, and the hook determination process ends. At this time, since the variables such as the hook result are not updated, the result when the hook detection is possible is taken over.
[0071]
In S406, it is determined whether the hook result read in S404 or S405 is ON or OFF. If the hook result is on, it is checked in step S407 whether the previous reading result is on. If the read result is also the previous ON, the value of the ON timer is checked in S410, and if the ON time value is larger than 0, 1 is subtracted in S413. Then, in S415, it is checked whether or not the subtraction result is 0. If the subtraction result is 0, ON is written to Result in S417.
[0072]
When the value of the on-time is 0 (S410), since ON is already written in the Result, the process ends without performing the subsequent processing. If the value of the on-time is still larger than 0 (S415), the process is terminated without updating the Result since the certification is in progress.
[0073]
If the previous time is not ON (S407), the current time has changed from OFF to ON. To start the ON verification, the initial value of 2200 is written to the ON timer (S409), and the process ends.
[0074]
As described above, only when the result of HOOK1 or HOOK2 changes from off to on and continues to be on for 2200 ms, it is recognized as on-hook and Result is updated to on. Otherwise, the Result is not updated.
[0075]
Similarly to the above, if the off-hook authorization is off (S406), it is checked whether the previous reading result was off (S408), and if it was also off last time, the off-timer check is performed. Perform (S411), and if it is larger than 0, subtract 1 by 1 (S414). If the subtraction result is 0 (S416), OFF is written to Result (S418). If the value of the off-time is 0 (S411), the result has already been written in the Result, so that the processing is terminated without executing the subsequent processing. If the value of the off timer is larger than 0 (S416), the process is terminated without updating the Result because the certification is in progress.
[0076]
If the previous time is not OFF in S408, the current time has changed from ON to OFF. In S412, the initial value of 200 is written to the OFF timer to start the OFF verification, and the process is terminated. . The above is the hook determination process.
[0077]
In S312 of the dial processing flow shown in FIG. 3, this variable Result is read, and it is determined whether dial termination is possible.
[0078]
In the above embodiment, the speaker 20 is turned off during dial transmission to prevent the howling phenomenon. However, for the telephone line, the telephone 23 connected to the T1 / T2 terminal and the line capturing unit of the communication device are connected. When connected in parallel, the speaker 20 may be turned off even when the dial is not being transmitted.
[0079]
Further, as long as the communication device is connectable to a telephone, the above-described embodiment can be applied to communication means other than the facsimile device.
[0080]
【The invention's effect】
According to the first aspect of the present invention, in a communication device having an inexpensive configuration that does not use a DC power supply dedicated to hook detection, it is possible to eliminate the howling phenomenon during off-hook dialing, and to provide no discomfort to the user. In addition, there is an effect that a failure of the communication device can be prevented.
[0081]
According to the second aspect of the present invention, the line monitor speaker is turned off at an arbitrary timing during the period when the dial signal is transmitted from the communication device while the telephone is off-hook, so that howling can be performed at an arbitrary timing. This has the effect that it can be prevented beforehand.
[0082]
According to the third aspect of the present invention, since the monitor speaker is turned off only during the period between the dial digits in the period during which the dial signal is being transmitted, howling is prevented beforehand and the dial signal is prevented. At the time of transmission, the line monitor sound is emitted from the speaker, so that the user can be notified of the dial signal transmission state.
[0083]
According to the invention described in claim 4, since the monitor speaker is turned off only during the period in which the telephone is connected to the line during the period in which the dial signal is transmitted, howling is prevented beforehand. It has the effect of being able to.
[0084]
According to the fifth aspect of the invention, when both the telephone and the communication means are connected to the telephone line, the line monitor speaker is turned off, so that howling can be prevented beforehand.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a communication device 100 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the communication device 100.
FIG. 3 is a flowchart showing an off-hook dial operation of the facsimile apparatus FS1 and a control operation of the speaker 20 for preventing a howling phenomenon.
FIG. 4 is a timing chart in the embodiment.
FIG. 5 is a flowchart showing a hook determination process in the embodiment and a control process of the speaker 20 during this process.
FIG. 6 is a circuit diagram showing a conventional communication device 200.
[Explanation of symbols]
100 communication device,
1: Diode bridge,
2 ... P relay,
3 ... CML relay,
4 ... Transformer,
5 ... 2-wire to 4-wire conversion circuit,
6, 8 ... hook detector,
7 ... H relay,
9 ... H detection relay,
10 ... CI detection circuit,
20 ... speaker,
22 ... Speaker controller.

Claims (5)

Communication means for performing communication by connecting to a telephone line;
Connection means for connecting a telephone to the telephone line via the communication means;
Hook state detecting means for detecting the hook state of the telephone based on a line current by connecting the telephone to the telephone line via the connection means while the communication means is capturing the telephone line; ;
Control means for turning off a line monitor speaker when detecting the hook state of the telephone;
A communication device comprising: Communication means for performing communication by connecting to a telephone line;
Connection means for connecting a telephone to the telephone line via the communication means;
Hook state detecting means for detecting the hook state of the telephone based on a line current by connecting the telephone to the telephone line via the connection means while the communication means is capturing the telephone line; ;
Dial signal sending means for sending a dial signal from the communication means while the telephone is off-hook;
Speaker off means for turning off a line monitor speaker during a dial transmission operation period;
A communication device comprising: In claim 2,
The communication device, wherein the speaker-off means turns off a speaker for line monitoring between one dial digit and the next dial digit during the dial sending operation period. In claim 2,
The communication device according to claim 1, wherein said speaker-off means turns off a line monitor speaker during a period in which said telephone is connected to said telephone line during said dial transmission operation period. Communication means for performing communication by connecting to a telephone line;
Connection means for connecting a telephone to the telephone line via the communication means;
Hook state detecting means for detecting the hook state of the telephone based on a line current by connecting the telephone to the telephone line via the connection means while the communication means is capturing the telephone line; ;
Control means for turning off a line monitor speaker;
A communication device, characterized in that the control means turns off a line monitor speaker when both the telephone and the communication means are connected to the telephone line.

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