JPS638671B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a facsimile apparatus, and more particularly to a facsimile apparatus characterized in that it is configured to be able to detect the quality of received images regardless of the length of recording paper.

In general, in facsimile devices, if the signal is not decoded correctly by the receiving device, the received image quality will deteriorate, which is undesirable. A detection circuit is installed to count the number of lines that have not been decoded normally, and when the counted value reaches a preset value, RTN (Retrain Negative) is sent from the receiving device.
It is configured to send a signal to the transmitting device to inform it that the received image quality is poor, and when the transmitting device receives the RTN signal, it lights up a poor communication lamp to warn that the document should be resent.

However, in conventional facsimile machines,
Since the detected value of the number of erroneous lines is fixed at a constant value, the quality of the image varies depending on the length of the received document. For example, if it is set to indicate a communication failure when there is an error in 20 lines, the determination of image quality will naturally differ depending on whether the recording paper is 20 cm or 1 m long.

Therefore, the present invention has been made in view of this point.
To provide a facsimile device configured to uniformly detect the quality of received images regardless of the length of recording paper.

Embodiments of the present invention will be described below with reference to the drawings. The drawing shows the configuration of a facsimile receiving device.
is a modem circuit that connects the telephone line and the receiving circuit.
Demodulates the signal sent from the transmitter. A decoding circuit 2 decodes the encoded signal, and the decoded signal is supplied to the recording device 3 and recorded. 4 is an error detection circuit to which the decoded signal is supplied, and when the signal for one line is supplied, it detects whether it is composed of, for example, 2048 bits, and if it is composed of 2048 bits,
An output is generated from the OK terminal and supplied to the first counter 5, and if it is smaller or larger than 2048 bits, an output is generated from the NG terminal and supplied to the up terminal of the second counter 6, which is composed of an up/down counter. There is. 1st counter 5
is composed of an up counter, and when the count value reaches N, the output is supplied to the down terminal of the second counter 6. 7 is a coincidence detection circuit that detects coincidence between the counted value of the second counter 6 and the constant M set in the constant setting circuit 8, and the detection signal is supplied to the control circuit 9 that controls the entire receiving device. There is.

Next, the operation of the present invention having such a configuration will be explained.

The signal from the transmitting device is transmitted to the modem circuit 1 of the receiving device.
After being demodulated via the decoding circuit 2 and recording by the recording device 3, at the same time, the error detection circuit 4 detects whether or not the decoded signal has been correctly decoded. It is done. If the decoding is normal, the first counter 5 counts the number of normally decoded lines. At this time, when the value of the first counter 5 reaches N, the output is supplied to the down terminal of the second counter 6, but if the second counter 6 is zero, the second counter 6 is configured not to go down below that value. There is.
On the other hand, if there is an error in the decoded signal, an output is supplied from the NG terminal of the error detection circuit 4 to the UP terminal of the second counter 6, so that the second counter 6 is incremented by one. In this way, the second counter 6 is incremented by 1 every time there is an error in the decoded line signal. However, normal decoding continued and the first
When the value of the counter 5 reaches N, the output is supplied to the down terminal of the second counter 6, so that the value of the second counter 6, which counts the number of error lines, is subtracted by 1 each time. Thus, during the recording period, the value of the second counter 6 repeatedly increases due to the NG terminal output of the error detection circuit 4 and decreases due to the output of the first counter 5. If there are few errors, the value of the second counter 6 repeatedly increases. Since the value of 6 is not large and is smaller than the constant M set in the constant setting circuit 8, no detection signal is generated from the coincidence detection circuit 7.

However, when the number of erroneously decoded lines increases, the value of the second counter 6 increases and becomes equal to the constant M set in the constant setting circuit 8, and a match is detected in the match detection circuit 7, and the detection signal is The signal is supplied to the control circuit 9. The control circuit 9 that read the detection signal indicates that the received image quality is poor.
It acts to immediately stop reception or to send an RTN signal to the transmitter after reception is completed to indicate a communication failure.

By appropriately selecting the value N at which the output is generated from the first counter 5 and the constant M of the constant setting circuit 8, it is possible to detect the quality of the image in units of, for example, 10 cm of the recording paper.

FIG. 2 is a diagram showing another embodiment, in which the second counter 6 is set to a constant M by the constant setting circuit 8, counts down by the output of the NG terminal of the error detection circuit 4, and by the output of the first counter 5. It is configured so that it is not counted up beyond a constant M. And the coincidence detection circuit 7
is configured to detect that the second counter 6 has reached zero, and supplies the detection output to the control circuit 9. Therefore, the second counter 6 calculates - from the constant M every time there is an error in the decoded line signal.
1 and the value of the first counter 5 becomes N after normal decoding, the second counter 6 increases by +1 each time.
be done. Thus, during the recording period, the value of the second counter 6 repeatedly goes down due to the NG terminal output of the error detection circuit 4 and goes up due to the output of the first counter 5, and when there are few errors, the value of the second counter 6 increases. The value does not become zero, and no detection signal is generated from the coincidence detection circuit 7. However, when the number of erroneously decoded lines increases, the value of the second counter 6 becomes zero, a coincidence is detected by the coincidence detection circuit 7, and a detection signal is supplied to the control circuit 9.

As described above, the facsimile apparatus of the present invention adds or subtracts the number of erroneous lines from the decoded line signal, and at the same time counts the number of normal lines, and when the predetermined number of lines is reached, the number of erroneous lines is counted. It is configured to repeat the operation of subtracting or adding from the counted value, and when the number of error lines increases and the counted value becomes larger than the value to be subtracted and reaches a preset value, or when it is subtracted and reaches zero. By configuring the system to generate a signal indicating communication failure, it is possible to detect the quality of the received image at a constant rate regardless of the length of the recording paper, which is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a facsimile apparatus according to the present invention, and FIG. 2 is a block diagram showing another embodiment. DESCRIPTION OF SYMBOLS 1...Modem circuit, 2...Decoding circuit, 3...Recording device, 4...Error detection circuit, 5...First counter, 6
...Second counter, 7. Match detection circuit, 8. Constant setting circuit, 9. Control circuit.

Claims (1)

[Claims] 1. A means for detecting whether the decoded line signal is normal or not, a first counter that counts the number of normal lines by the means and generates an output when the number reaches a predetermined value, and adds the number of erroneous lines. a second counter that counts (or subtracts) and is subtracted (or added) based on the output of the first counter, and configured to generate a signal indicating communication failure when the value of the second counter reaches a predetermined value. A facsimile device characterized by: