JP4175331B2 - Facsimile device with external telephone - Google Patents

Description

  The present invention relates to an improvement of a facsimile apparatus having an external telephone set.

  2. Description of the Related Art Conventionally, a facsimile apparatus with an external telephone in which an external telephone is connected to the facsimile apparatus is known.

FIG. 3 shows a basic configuration of this type of facsimile apparatus with an external telephone. A main unit 100 including a main control unit 101 and a modem 102 is connected to a telephone line L via a main line relay CML. An external telephone TEL is connected to the telephone line L via the line switching relay SW together with an off-hook detector OH, and a call incoming detector CI is further connected in parallel to the telephone line L. ing. The following patent document discloses a facsimile apparatus with an external telephone set.
JP-A-6-70084

  By the way, in this kind of facsimile apparatus with an external telephone, a 16 Hz ringing signal from the telephone line L is detected by the incoming call detector CI. Since the dial pulse to be output is 10 Hz or 20 Hz and the ringing signal is close in frequency, it is erroneously determined as a ringing signal from the outside line, the modem 102 is automatically terminated, the main line relay CML is closed, and the line switching is performed. The external switch TEL may be disconnected from the telephone line L by opening the relay SW.

  For this reason, in order to solve such a problem, the main control unit 101 includes a device that discriminates a dial pulse signal from a ringing signal in addition to the detection by the off-hook detector OH. When the number of external telephones TEL connected to the line L is large, the off-hook detector OH may erroneously determine the dial pulse signal output by the external telephone TEL as a calling signal.

  The present invention has been proposed to solve such a problem, and an object of the present invention is to provide an external device that can reliably distinguish between a call signal from an external telephone and an incoming call signal from an external telephone with a simple configuration. It is to provide a facsimile machine with a telephone.

The facsimile apparatus with an external telephone according to claim 1 is a facsimile apparatus in which an external telephone provided with an off-hook detector is additionally connected in parallel to a telephone line to which a modem is connected via a main line relay. An incoming call detector for detecting a ringing signal and a dial tone detector for detecting a dial tone are provided on a telephone line, and an off-hook detector, an incoming call detector, and a dial tone detector are monitored to detect a main line relay. The control means determines that the signal detected by the incoming call detector is an incoming call from an outside line at the time of on- hook , and for a predetermined time after detecting the off-hook signal. Detects the presence or absence of continuous disconnection of the dial tone signal and the off-hook signal. Upon detection of a continuous disruption of the items, while determining that the dial calling operation by external telephone, without detecting a dial tone signal during detects a continuous disruption of the off-hook signal, incoming call detector detects is characterized in that it is determined that the incoming call signal from the outside line.

  According to the second aspect of the present invention, a line switching relay is further provided between the external telephone and the telephone line, and when the control means determines that the incoming call is from the external line, the main line relay is closed and the telephone line is disconnected. While connecting to the modem, the line switching relay is opened to disconnect the external telephone from the telephone line.

  According to a third aspect of the present invention, each of the off-hook detector, the incoming call detector, and the dial tone detector is composed of a photocoupler that is driven by receiving an AC signal.

  According to the facsimile apparatus with an external telephone according to any one of claims 1 to 3, a dial tone detector is provided in addition to the off-hook detector and the incoming call detector. Since continuous disconnection is detected, it is possible to definitely discriminate between outgoing calls from external telephones and incoming calls from outside.

  According to claim 2, a line switching relay is further provided between the telephone and the telephone line, and when the control means determines that the incoming call is from the outside line, the main line relay is closed and the telephone line is connected to the modem. Since the operation of disconnecting the external telephone from the telephone line is executed by opening the line switching relay, the external telephone is surely disconnected when an incoming call is received.

  According to the third aspect, since the off-hook detector, the incoming call detector, and the dial tone detector are all configured by a photocoupler that is driven by receiving an AC signal, the configuration is simple and is not easily affected by noise. .

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a main configuration of a facsimile apparatus with an external telephone according to the present invention.

  A facsimile apparatus 10 including a main control unit 1, a modem 2, an operation unit 3, a storage unit 4 and the like, which is constituted by a CPU or the like, is connected to a telephone line L, and the telephone line L is interposed with a main line relay CML. An external telephone TEL, an incoming call detector CI, and a dial tone detector TD to which an off-hook detector OH is added are connected in parallel with the modem 2 through the facsimile communication transformer TR and the line switching relay SW. ing.

  Here, the facsimile apparatus 10 stores a program necessary for the main control unit 1, the modem 2, the operation unit 3, and the facsimile apparatus configured by a CPU or the like, or temporarily stores data necessary for communication control. The main control unit 1 constitutes control means for controlling the basic facsimile operation described below, and the main control unit 1 opens the contact of the main line relay CML when the facsimile apparatus is on standby. The contact of the line switching relay SW is in a closed state.

  In this embodiment, the off-hook detector OH, the incoming call detector CI, and the dial tone detector TD are all configured by photocouplers that are driven by receiving an AC signal, but are not limited thereto.

  Next, the basic operation of this facsimile apparatus with an external telephone will be described.

1) Calling operation by an external telephone TEL A 45 V DC voltage is applied to the telephone line L during standby, and when the external telephone TEL is off-hooked, a loop current flows through the line L. As a result, the telephone line voltage is The voltage drops to about 5V. The exchange recognizes the off-hook state by this loop current and sends a 400 Hz dial tone to the telephone line.
The external telephone TEL confirms this dial tone and makes a dial call.
That is, a preset 10 Hz or 20 Hz dial pulse is output by the external telephone TEL, and the loop current flowing through the telephone line L is cut off.
The dial pulse at this time is also detected by the off-hook detector OH, and the main control unit 1 detects that the off-hook signal at this time is continuously broken. In the present invention, the following determination is made. Therefore, when the external telephone TEL is making such a dial call, the main line relay CML is prevented from being closed and the external telephone line L is disconnected.
When the exchange decodes the dial pulse generated by the dialing call, it sends a calling signal to the telephone line L of the called party, and when the called party responds to it and goes off-hook, it reverses the polarity of the voltage of the telephone line L, A call is made by connecting the caller and the callee. When the call is finished and the external telephone TEL is on-hooked, the telephone line L returns to the standby voltage.

2) Incoming call operation for call signal from outside line The telephone line L is applied with 45V DC voltage during standby, and when a 16Hz call signal is sent from the exchange to the line, the incoming call detector CI detects this. However, the main control unit 1 determines the incoming call by referring to the detection signals from the off-hook detector OH and the dial tone detector TD without receiving the modem 2 only by the detection by the incoming call detector CI. The main line relay CML is closed and the line relay SW is opened.

  Steps 101 to 112 in FIG. 2 are flowcharts showing an incoming call / dial call discrimination procedure executed by the control means.

  When the main control unit 1 detects the off-hook by the off-hook detector OH when the telephone line L is in a standby state, the main control unit 1 detects the dial tone signal and continuously cuts off the off-hook signal during a predetermined time thereafter. Whether or not is monitored (101, 102).

  Here, the predetermined time is specified in consideration of a delay time until the dial tone is sent to the telephone line L after the external telephone TEL goes off-hook, and is usually sufficiently longer than such a delay time. Set to a long time.

  If there is no dial tone within the predetermined time and there is a continuous disconnection of the off-hook signal, it is determined that the call signal has arrived, the main line relay CML is closed, the line switching relay SW is opened, and the modem 2 is received and facsimile reception is performed. When the facsimile reception is completed, the main line relay CML is opened and the line switching relay SW is closed (102106 to 112).

  That is, in the present invention, when an external telephone TEL makes a dial call, it always goes off-hook, and attention is paid to the fact that a dial tone is generated on the telephone line L, and such a principle is utilized. The incoming call is determined.

  However, if a dial tone is detected within the predetermined time, and if there is a continuous disconnection of the off-hook signal within the predetermined time, it is determined that the dial call is made by the external telephone TEL, and the main control unit 1 determines what No processing.

  Therefore, the main line relay CML and the line switching relay SW are held in a standby state, and as a result, the external telephone makes a call with the callee that has answered the call and makes a call until it goes on-hook (102 to 105). .

  If a dial tone is not detected within a predetermined time after detecting an off-hook, and if a continuous disconnection of the off-hook signal is not detected, the on-hook is detected and the process is terminated (104 to 106).

FIG. 2 is a block diagram showing a main configuration of a facsimile apparatus with an external telephone according to the present invention. 4 is a flowchart showing the basic operation of the facsimile apparatus with an external telephone of the present invention. It is a block diagram which shows the principal part structure of the conventional facsimile apparatus with an external telephone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control means 2 Modem L Telephone line TD Dial tone detector OH Off-hook detector CI Incoming call detector TEL External telephone CML Main line relay SW Line change relay

Claims (3)

In a facsimile machine in which an external telephone provided with an off-hook detector is additionally connected in parallel to a telephone line connected to a modem via a main line relay,
And a called detector for detecting a call signal from the external line, the dial tone detector for detecting a dial tone is provided on the telephone line, the off-hook detector, the incoming call detector, the dial tone detector monitoring And a control means for controlling the main line relay,
The control means includes
When on-hook, the signal detected by the incoming call detector is determined as an incoming call from the outside line,
After detecting the off-hook signal, it detects whether or not the dial tone signal and the off-hook signal are continuously broken for a predetermined time, and when the dial tone signal is detected during that time, it detects the continuous break of the off-hook signal thereafter. then, while determining that the dial calling operation by the external telephone, without detecting a dial tone signal during detects a continuous disruption of the off-hook signal, the signal from which the incoming call detector detects the outside line Facsimile device with an external telephone that determines that the call is an incoming call. In claim 1,
A line switching relay is further provided between the external telephone and the telephone line.
When the control means determines that the incoming call is from the outside line, the main line relay is closed and the telephone line is connected to the modem, while the line switching relay is opened and the external telephone is disconnected from the telephone line. A facsimile machine with an external telephone. In any one of Claims 1, 2.
The off-hook detector, the incoming call detector, and the dial tone detector are each a facsimile apparatus with an external telephone configured by a photocoupler that is driven by receiving an AC signal.

Images