JP4737101B2 - Communication device and noise removal method in communication device - Google Patents

Description

  The present invention relates to a communication device and a noise removal method in the communication device.

  There is a case where noise is generated in the audible voice band in the telephone terminal due to radiation and conduction noise. In facsimile communication, communication may not be established due to radiation and conduction noise.

For example, there is a communication / information terminal device that removes external and internal noise frequencies using a circuit composed of a coil and a capacitor (see, for example, Patent Document 1).
JP-A-9-275421

An object of the present invention is to provide a communication device and a noise elimination method in the communication device that reliably prevent the generation of unnecessary noise due to radiation / conduction noise.

In order to achieve the above object, the invention of claim 1 is directed to a network control device that transmits and receives a signal via a public network, and when the network control device is connected to the public network and receives a signal, Monitoring means for monitoring whether or not a received signal satisfies a predetermined condition; and a path between a transformer in the network control device and a modem for facsimile communication when the received signal satisfies the predetermined condition Insertion control means for controlling the insertion of an attenuator into the signal, and the predetermined condition is that a generation time of the received signal exceeds a predetermined time and a level of the received signal exceeds a predetermined level. it and state, and are the frequency of the received signal satisfies all that is a specific frequency, the attenuator is characterized by attenuating a signal exceeding the predetermined level of the specific frequency .

Further, according to the second aspect of the present invention, when a network control device that performs transmission / reception of a signal via a public line network connects to the public line network and receives the signal, whether or not the received signal satisfies a predetermined condition. or monitor, if the received signal is the predetermined condition is satisfied, and insert an attenuator in the path between the transformer and the facsimile communication modem in the network control device, the predetermined condition is that the receiver and the time of occurrence of the signal exceeds a predetermined time, and the level of the received signal exceeds a predetermined level state, and are the frequency of the received signal satisfies all that is a specific frequency The attenuator attenuates a signal exceeding the predetermined level at the specific frequency .

According to the first and second aspects of the present invention, communication can be performed without any problems even when external radiation / conduction noise is applied, as compared with the case where the present configuration is not provided.

  Embodiments of a communication apparatus and a noise removal method in the communication apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing an example of a schematic configuration of a facsimile machine 1 to which the present invention is applied.

  As shown in FIG. 1, a facsimile apparatus 1 includes a CPU 2 that controls the facsimile apparatus 1, a ROM 3 / RAM 4 that stores an operation program of the CPU 2, and a network control unit 5 that transmits and receives voice signals via a public line network. A FAX Modem 6 having a function of facsimile communication (transmission and reception) and a Codec / resolution conversion unit 7 that performs image encoding / decoding and resolution conversion are provided.

  FIG. 2 is a diagram illustrating an example of a detailed configuration of the network control unit 5.

  The line is connected to the line via the L1 / L2 terminal, and the line is connected to the Trans 9 via the Relay 8. The state of Relay 8 shown in FIG. 2 is a state in which the line is disconnected. When Relay 8 is activated and the switch is switched, the line is connected to Trans 9 and the communication state is switched. Since there are four lines between Trans9 and FAX Modem6, it is branched into a transmission path and a reception path, and filter circuits (111, 112) such as an attenuator (101, 102) and a BPF [Band-pass filter] are added respectively. And connected to FAX Modem6. The RING detector 12 is an element that detects a calling signal from the exchange when the line is disconnected, and is usually realized by a photocoupler.

  The insertion control unit 13 constituted by an analog switch or the like controls the insertion of the attenuators (101, 102) or the filter circuits (111, 112) into the transmission path and the reception path. Specifically, the FAX Modem 6 monitors the received signal power during communication, and the service tone of the exchange (such as a ringback tone or busy tone provided by the public network or a unique network), a FAX signal, DTMF (Dual Tone Multi Frequency) ) When the generation of a signal other than a signal has a predetermined condition, the insertion control unit 13 inserts the attenuator (101, 102) or the filter circuit (111, 112) into the transmission path and the reception path. Note that the predetermined condition is that a signal other than a service tone is generated for a predetermined time or more, a signal level is generated for a predetermined time or more and a predetermined time or more, a signal of a specific frequency is generated for a predetermined time or more, a signal of a specific frequency and a predetermined level or more A signal having a specific frequency, a predetermined level or higher, and a predetermined time or longer.

  Next, the processing procedure of the insertion control of the attenuator (or filter circuit) in which a signal other than the service tone or the like is generated for a predetermined time or longer will be described with reference to the flowchart shown in FIG.

  If a circuit in the network control unit is connected (S301) and the FAX Modem does not detect a signal (NO in S302), the process proceeds to S303. If the FAX Modem detects a signal (YES in S302), the process proceeds to S305. move on.

  When FAX Modem does not detect a signal (NO in S302), the time from the circuit connection is measured, and when Time Out is reached (YES in S303), the circuit in the network control unit is disconnected (S304), and the processing procedure is performed. finish.

  If the FAX Modem detects a signal (YES in S302), the type of the detected signal is identified, and if the signal is a service tone, FAX signal or DTMF signal (YES in S305), the process proceeds to S306, and If the signal is a signal other than a service tone, FAX signal, or DTMF (NO in S305), the process proceeds to S307.

  When the detected signal is a service tone, FAX signal, or DTMF signal (YES in S305), an operation corresponding to each signal is performed (for example, in the case of a busy tone, the line is opened and redial is performed. In the case of a FAX signal, Communication with the partner facsimile machine is started, and in the case of a DTMF signal, a designated operation such as switching to a telephone is performed) (S306), and the processing procedure ends.

  If the signal is a signal other than a service tone, FAX signal, or DTMF (NO in S305), the FAX Modem monitors the signal, and if the signal has not been generated for a predetermined time (NO in S307), the process returns to S302. If the signal is generated for a predetermined time or longer (YES in S307), an attenuator (or filter circuit) is inserted into the transmission path and the reception path (S308), and the processing procedure is terminated.

  Next, referring to the flowchart shown in FIG. 4, the processing procedure of the insertion control of the attenuator (or filter circuit) in which the signal other than the service tone or the like has a signal level higher than a predetermined level and generated for a predetermined time or longer is a predetermined condition. I will explain.

  If a circuit in the network control unit is connected (S401) and the FAX Modem does not detect a signal (NO in S402), the process proceeds to S403. If the FAX Modem detects a signal (YES in S402), the process proceeds to S405. move on.

  When FAX Modem does not detect a signal (NO in S402), the time from the circuit connection is measured, and when Time Out is reached (YES in S403), the circuit in the network control unit is disconnected (S404), and the processing procedure is performed. finish.

  If the FAX Modem detects a signal (YES in S402), the type of the detected signal is identified, and if the signal is a service tone, FAX signal, or DTMF signal (YES in S405), the process proceeds to S406, and If the signal is a signal other than a service tone, FAX signal, or DTMF (NO in S405), the process proceeds to S407.

  If the detected signal is a service tone, FAX signal, or DTMF signal (YES in S405), an operation corresponding to each signal is performed (for example, in the case of a busy tone, the line is opened and redial is performed. In the case of a FAX signal, Communication with the partner facsimile machine is started, and in the case of a DTMF signal, a designated operation such as switching to a telephone is performed) (S406), and the processing procedure ends.

  If the signal is a signal other than a service tone, FAX signal, or DTMF (NO in S405), FAX Modem monitors the signal, and if the signal level is equal to or lower than a predetermined level (NO in S407), the process returns to S402. If the signal level is equal to or higher than the predetermined level (YES in S407), the process proceeds to S408.

  If the signal level is equal to or higher than the predetermined level (YES in S407), the FAX Modem monitors the signal. If the signal is not generated for a predetermined time (NO in S408), the process returns to S402, and the signal is generated for the predetermined time or longer. If so (YES in S408), an attenuator (or filter circuit) is inserted into the transmission path and the reception path (S409), and the processing procedure is terminated.

  Next, the flowchart shown in FIG. 5 shows the processing procedure of insertion control of an attenuator (or filter circuit) in which a signal other than a service tone or the like is a signal of a specific frequency and is generated at a predetermined level or more and for a predetermined time or more. The description will be given with reference.

  If a circuit in the network control unit is connected (S501) and the FAX Modem does not detect a signal (NO in S502), the process proceeds to S503. If the FAX Modem detects a signal (YES in S502), the process proceeds to S505. move on.

  When FAX Modem does not detect a signal (NO in S502), the time from the circuit connection is measured, and when Time Out is reached (YES in S503), the circuit in the network control unit is disconnected (S504), and the processing procedure is performed. finish.

  If the FAX Modem detects a signal (YES in S502), the type of the detected signal is identified, and if the signal is a service tone, FAX signal, or DTMF signal (YES in S505), the process proceeds to S506, and If the signal is a signal other than a service tone, FAX signal, or DTMF (NO in S505), the process proceeds to S507.

  When the detected signal is a service tone, FAX signal, or DTMF signal (YES in S505), an operation corresponding to each signal is performed (for example, in the case of a busy tone, the line is opened and redial is performed. In the case of a FAX signal, Communication with the partner facsimile machine is started, and in the case of a DTMF signal, a designated operation such as switching to a telephone is performed) (S506), and the processing procedure is terminated.

  If the signal is a signal other than a service tone, FAX signal, or DTMF (NO in S505), the FAX Modem monitors the signal, and if the signal is not a specific frequency (NO in S507), the process returns to S502, If the signal has a specific frequency (YES in S507), the process proceeds to S508.

  If the signal has a specific frequency (YES in S507), the FAX Modem monitors the signal. If the signal level is lower than the predetermined level (NO in S508), the process returns to S502, and the signal level is higher than the predetermined level. If yes (YES in S508), the process proceeds to S509.

  If the signal level is equal to or higher than the predetermined level (YES in S508), the FAX Modem monitors the signal. If the signal is not generated for a predetermined time (NO in S509), the process returns to S502, and the signal is generated for the predetermined time or longer. In the case (YES in S509), an attenuator (or filter circuit) is inserted into the transmission path and the reception path (S510), and the processing procedure ends.

  A configuration using a phase inverter instead of the attenuator or the filter circuit is also applicable.

1 is a block diagram illustrating an example of a schematic configuration of a facsimile apparatus to which the present invention is applied. It is a figure which shows an example of a detailed structure of a network control part. It is a flowchart which shows the process sequence of insertion control of the attenuator (or filter circuit) which makes generation | occurrence | production of signals other than a service tone etc. predetermined time or more. It is a flowchart which shows the process sequence of insertion control of the attenuator (or filter circuit) which makes signal levels other than a service tone etc. generate | occur | produce a signal level more than predetermined level and more than predetermined time as predetermined conditions. It is a flowchart which shows the process sequence of insertion control of the attenuator (or filter circuit) which makes signals other than a service tone etc. a signal of a specific frequency, generation | occurrence | production more than predetermined level, and predetermined time more than predetermined time.

Explanation of symbols

1 Facsimile device 2 CPU
3 ROM
4 RAM
5 Network control unit 6 FAX Modem
7 Codec / Resolution Converter 8 Relay
9 Trans
101, 102 Attenuator 111, 112 Filter circuit 12 RING detector 13 Insertion control unit

Claims (2)

A network control device for transmitting and receiving signals via a public network;
Monitoring means for monitoring whether or not the received signal satisfies a predetermined condition when the network control device is connected to the public line network and receives the signal;
Insertion control means for controlling to insert an attenuator in the path between the transformer in the network control device and the facsimile communication modem when the received signal satisfies the predetermined condition, and
The predetermined condition is that the generation time of the received signal exceeds a predetermined time, the level of the received signal exceeds a predetermined level, and the frequency of the received signal is a specific frequency. Ri der that meets all,
The attenuator attenuates a signal exceeding the predetermined level of the specific frequency . When a network control device that transmits and receives signals via a public network connects to the public network and receives a signal, it monitors whether the received signal satisfies a predetermined condition,
If the received signal satisfies the predetermined condition, an attenuator is inserted in the path between the transformer in the network control device and the modem for facsimile communication,
The predetermined condition is that the generation time of the received signal exceeds a predetermined time, the level of the received signal exceeds a predetermined level, and the frequency of the received signal is a specific frequency. Ri der that meets all,
The noise attenuating method in a communication apparatus , wherein the attenuator attenuates a signal of the specific frequency exceeding the predetermined level .

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