JP2877529B2 - Communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device which shares one line with another communication device and performs a communication operation in accordance with a remote instruction from the other communication device.

[0002]

2. Description of the Related Art Conventionally, there has been known a facsimile apparatus which shares one telephone line with a telephone and performs facsimile communication in accordance with a remote instruction from the telephone. Such a facsimile machine is installed at a remote place from a telephone connected via a network control unit (NCU). If the user responds to the call signal (incoming call) from the line using the telephone, and as a result the other party is a facsimile, the user operates the hook of the telephone or a ten-key for dialing to change the line from the telephone to the facsimile apparatus. To perform facsimile reception (remote reception).

[0003] The facsimile apparatus N
The CU is configured as shown in FIG.

In FIG. 1, terminals L1 and L2 are connected to a line N, and a telephone is connected to terminals T1 and T2. When the user off-hooks the telephone in response to a call signal from the line and the other party is a facsimile, the user operates the telephone to dial a predetermined number (outputs a DTMF signal) DT to receive the facsimile remotely.
The MF signal appears at the terminal A via the transformer 8 from the T1 and T2 terminals. The terminal A is connected to a DTMF receiver, and the control unit recognizes the number output from the telephone from the output of the DTMF receiver.
The communication is performed by switching the L relay 1 to the b side. As described above, remote reception has been realized.

[0005]

However, in the above-mentioned conventional example, the user is required to obtain a D
There has been a problem that the DTMF detector operates when the TMF signal is mixed, the CML relay is switched during the call, and the call is disconnected.

[0006] When a number to be remotely received is included in the number to be called by the user, the CML relay is switched, and there is a problem that the call cannot be made. In order to solve this problem, it has been proposed to perform remote reception only within a certain period of time after receiving a call. However, polling cannot be started by remote control, and malfunction may occur due to contamination from other lines (crosstalk). There was not perfect.

[0007]

According to the present invention, the state of formation of a current loop between a line and another communication device (for example, a telephone) is detected by a detection unit, and the line connection unit is operated based on the detection result. In this case, the other communication device is disconnected from the line, and the receiving device shifts to receiving a remote instruction signal from the other communication device, thereby enabling reliable remote communication.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows the configuration of a facsimile apparatus embodying the present invention. In the figure, reference numeral 101 denotes a control unit including a microprocessor or the like, a CPU (central processing unit) 113, a ROM (read only memory) 114, and a RAM (random access memory).
115, buffer memory 112, line memory 110,
The encoding / decoding unit 111 controls the entire image input / output and communication processing. The ROM 114 stores a control program described later, and the RAM 115 is used as a work area of the CPU 113.

Image input / output is performed by the reading unit 100, the recording unit 10
2 is performed.

That is, the reading of the original image data is performed by
The reading is performed by the reading unit 100 including a CCD (charge storage element) sensor, a document conveying system, and the like. The received image data or the image data read by the reading unit 100 during the copy operation is recorded by the recording unit 102 including a thermal printer, an ink jet printer, or the like.

Input / output of image data between the reading unit 100, the recording unit 102, and the encoding / decoding unit 111 is performed via a line memory 110 in units of one line. Also, data input / output between the encoding / decoding unit 111 and the communication circuit is controlled via a buffer memory 112 having a processing unit (for example, a predetermined number of pages) larger than one line.
The encoding / decoding unit 111 performs encoding / decoding processing for suppressing redundancy, and may be configured by software of the CPU 113.

Connection to a central line N such as a telephone line and data input / output are performed by a modem 106 and an NCU (network control unit) 107. The NCU 107 is connected to a telephone for telephone and manual control or an answering machine 16.

The operation panel 103 includes ten keys for inputting telephone numbers and various function keys. The operation panel 103 is provided with a display 104 used for displaying a telephone number, time, and the like.

FIG. 2 is a diagram showing an NCU of this embodiment.
1 is a CML relay. Reference numeral 2 denotes a current sensor, which is composed of a coil and a Hall element provided in the vicinity of the coil and insulated from the coil. The coil generates a magnetic field having a strength proportional to the current flowing through the coil. By converting to a current of a magnitude proportional to the strength of the magnetic field,
An output current proportional to the coil current is obtained. The output of the current sensor 2 is input to the comparator 3 and becomes a DCDET signal indicating the presence or absence of a current. The DCDET signal is sent to the control unit 1
01 is output.

7 is a power supply for applying a direct current to the telephone,
Reference numeral 6 denotes a constant current circuit for increasing the AC impedance of the power supply 7, reference numeral 5 denotes a relay for connecting the telephone to a line or DC application circuit, and reference numeral 8 denotes a transformer.

Next, the operation of remote reception in the above configuration will be described with reference to FIG. FIG. 3 shows the control unit 101.
(Or the CPU 113), and the procedure in the figure is stored in the ROM 114.

In FIG. 3, when the telephone is turned off by the DCDET signal, the control section 101 advances the control to step S1. At this time, the state of each relay is as shown in FIG. Therefore, the DTMF receiver is disconnected from the line at the C-side terminal of the relay 5, and does not remotely receive the DTMF signal generated for calling from the telephone. In step S1, the DTDET signal is further monitored and 0.5 seconds to
When the absence of the current for about 1.5 seconds is detected, it is determined that the hooking is present, and the process proceeds to step S2. If there is no hooking, step S1 is looped. When the relay 5 is switched to the b side in step S2, a DC current flows from the DC power supply 7 to the telephone 16 through the constant current circuit 6. Then, proceeding to step S3, the control unit monitors the output of the DTMF receiver 117,
DTMF "5" is dialed or checked. At this time, the telephone and the DTMF receiver are connected. However, since the line is disconnected at the d-side terminal of the relay 5, a user who does not have a fear of malfunction due to crosstalk dials "5" from the telephone and receives a DTMF signal "5". Is T
1. From the T2 terminal, the C side contact of the relay 5 and the capacitor 9,
Appears at the terminal A of the NCU via the transformer 8, is input to the DTMF receiver, and when the control unit recognizes this, proceeds to reception, and remote reception is performed. Therefore, remote reception can be performed both at the time of calling and at the time of receiving, and there is no fear of malfunction due to crosstalk.

The remote reception has been described above.
Other functions of the facsimile, such as outputting a communication management report remotely or transmitting an image stored in the memory to another facsimile, can also be remotely controlled.

In the above-described embodiment, the facsimile apparatus that performs facsimile communication in response to a remote instruction from the telephone has been described. However, the transmission of the remote instruction is not limited to the telephone. Further, the communication device to be remotely controlled is not limited to a facsimile device, and can be applied to various communication devices such as teletex.

[0021]

As described above, according to the present invention, communication based on a remote instruction from another communication device can be reliably performed, and malfunction of the device due to erroneous detection of a remote instruction can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a facsimile apparatus of the present embodiment.

FIG. 2 is a circuit diagram of a network control unit according to the embodiment.

FIG. 3 is a flowchart showing a control operation of the present embodiment.

FIG. 4 is a circuit diagram of a conventional network control unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 CML relay 2 Current sensor 3 Amplifier 4 Hybrid transformer 5 Relay 6 Constant current circuit 7 Power supply 8 Transformer 9 Capacitor 100 Reading unit 101 Control unit 102 Recording unit 103 Operation panel 104 Display unit 105 106 Modem 107 NCU 110 Line memory 111 Encoding / Decoding section 112 Buffer memory 113 CPU 114 ROM 115 RAM 117 DTMF receiver

Claims (2)

(57) [Claims] 1. A communication device that shares one line with another communication device and performs a communication operation in accordance with a remote instruction from the another communication device. A line connection unit for selectively connecting to the communication device and the communication unit; a unit for receiving a remote instruction signal from the another communication device; and a state of forming a current loop between the other communication device and the line. A communication device, comprising: means for detecting; and means for disconnecting the other communication device from the line in response to detection by the detection device, and thereafter receiving a remote instruction signal from the other communication device. 2. The communication device according to claim 1, wherein the remote instruction signal is a specific DTMF signal.