JP3096313B2 - Facsimile machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus, and more particularly to a facsimile apparatus having an ECM transmission / reception mode for retransmitting image data based on transmission error detection based on a predetermined communication procedure between a transmitter and a receiver.

[0002]

2. Description of the Related Art Conventionally, in the G3 facsimile procedure, a process for determining a minimum scanning time of one line is performed between a transmitter and a receiver prior to image transmission and reception.

That is, the receiver declares the minimum scan time of one line that can be received by the receiver, and the transmitter determines the minimum scan time of one line that can be received by the receiver and the minimum scan time of one line that the transmitter can transmit. The longer time of the scanning time is 1
The minimum scanning time of the line is set, and the receiver is notified.

[0004] Thereafter, at the time of image transmission, when the one line of information is encoded and transmitted, if it is within the minimum scanning time notified to the receiving side, a fill is inserted until that time. That is, the transmitter transmits image information in accordance with the recording capability of the receiver.

On the other hand, conventionally, ECM (error correction mode) transmission is known. In this ECM transmission, a receiver declares a minimum receivable scanning time of one line.

However, since the ECM transmission is based on memory transmission (reception), the transmitter declares 0 (ms) as the minimum scanning time. That is, the weight according to the receiving capability of the receiver is controlled by the flow control between partial pages.

Specifically, the PPS-Q transmitted by the transmitter is
For the signal, the receiver generates an R
Transmit the NR signal. Upon receiving the RNR signal, the transmitter transmits the RR signal. Thereafter, the RNR signal, RR
When transmission and reception of the signal are repeated and the receiver becomes ready for reception, the MCF signal is transmitted. Then, the transmitter
The next partial page is transmitted.

Here, if the MCF signal cannot be received even after the timer (T5: 1 minute) has elapsed after transmitting the RR signal, the transmitter has terminated the communication as a T5 timer over error.

[0009]

However, the conventional EC
In M transmission, since image transmission is performed irrespective of the recording capability of the receiver, if the recording capability of the receiver is low or if the image information to be transmitted is not efficiently compressed, 1 The recording of the partial page is performed by the T5 timer (1
Minutes) may not be completed within minutes.

In this case, there is a problem that a communication error occurs even though no transmission error has occurred, and the remaining image information cannot be transmitted.

[0011] The object of the present invention is to solve the above-mentioned problems, regardless of the capability of the receiving side and the compression efficiency of image information.
An object of the present invention is to provide a facsimile apparatus that can perform normal ECM transmission and reception.

[0012]

According to the present invention, there is provided a facsimile apparatus having an ECM transmission / reception mode for retransmitting image data based on transmission error detection based on a predetermined communication procedure. A means for detecting a minimum scanning time on the image receiving side, an estimating means for estimating a reception processing time of the partial page on the image receiving side based on the minimum scanning time and the transmission image data, and a reception predicted by the estimating means. A configuration is provided in which control means is provided for determining the waiting time of the procedure signal from the receiving side between partial pages based on the receiving processing time of the partial page on the side.

[0013]

According to the above arrangement, on the transmitting side, the reception processing time of the partial page of the partner receiver is estimated based on the minimum scanning time of the receiver and the minimum scanning time, and the partial page is estimated based on the estimation result. By determining the wait time between them, ECM transmission can be performed according to the reception state.

[0014]

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 according to the present invention.

In FIG. 1, reference numeral 2 denotes a telephone network used for data communication or the like, so that it is connected to a terminal of the line to control connection of a telephone exchange network or switch to a data communication path. An NCU (network controller) that holds the loop. The signal line 2a is a telephone line.

The NCU 2 receives the signal on the signal line 34a. If the signal level is "0", the NCU 2 turns off the internal CML relay and connects the telephone line to the telephone, that is, the signal line 2b. When the signal level of the signal line 34a is "1", the internal CML relay is turned on, and the telephone line is connected to the facsimile apparatus, that is, the signal line 2c. In a normal state, the telephone line is connected to the telephone with the CML relay turned off.

Reference numeral 6 denotes a hybrid circuit for separating a transmission system signal and a reception system signal. The transmission signal on the signal line 19a passes through the signal line 2c, is transmitted to the telephone line via the NCU 2, and is transmitted to the other party. Is sent from the NCU
After passing through 2, the signal passes through the signal line 2c and is output to the signal line 6a.

Reference numeral 8 denotes a reading circuit which sequentially reads image signals for one line in the main scanning direction from a transmission original,
A signal sequence representing binary values of white and black is created. It is composed of an imaging device such as a CCD (charge coupled device) and an optical system. The binary signal sequence of white and black is output to the signal line 8a.

Reference numeral 10 denotes a circuit which inputs read data output to the signal line 8a and outputs MH (Modified Huffman) encoded or MR (Modified Read) encoded data to the signal line 10a. When the encoding of one line is completed, the encoding circuit 10 outputs a signal of signal level "1" to the signal line 10c when the image is completely white, and outputs a signal of signal level "0" to the signal line 10c when the image is not completely white. And generates a one-line encoding end pulse on the signal line 10b.

Reference numeral 12 denotes a memory circuit for storing data output to the signal line 10a. Since the facsimile apparatus transmits a plurality of frames as one block at a time and then retransmits an erroneous frame, at least one block of memory is required. Memory circuit 1
2 outputs the frame information to the signal line 12a when the frame number to be transmitted is output to the signal line 34c.

The code 14 adds an address field, a control field, an FCF field, and an FIF field (where the frame number being transmitted is stored) before the encoded data output to the signal line 12a. An HDLC framing circuit outputs the information obtained by converting the information into the HDLC format to the signal line 14a.
The HDLC framing circuit 14 sends a flag for flow control on the transmitter side to the signal line 14a when the signal of the signal level "1" is output to the signal line 34d.

Reference numeral 16 denotes a known CCITT recommendation V27.
ter (differential phase modulation) or V29 (quadrature modulation)
This is a modulator that performs modulation based on. The modulator 16
The signal of the signal line 14a is input, and the modulated signal is transmitted to the signal line 16a.
Output to

Reference numeral 18 denotes a known CCITT recommendation V21.
This is a modulator that performs modulation based on. The modulator 18
The procedural signal on the signal line 34b is input, modulated, and the modulated data is output to the signal line 18a.

Reference numeral 19 denotes a signal line 16a and a signal line 18a.
, And outputs an addition result to the signal line 19a.

Reference numeral 20 denotes a known CCITT recommendation V21.
Is a demodulator that performs demodulation based on. The demodulator 20
The signal on the signal line 6a is input, V21 demodulation is performed, and demodulated data is output to the signal line 20a.

Reference numeral 22 denotes a known CCITT recommendation V27.
ter (differential phase modulation) or V29 (quadrature modulation)
Is a demodulator that performs demodulation based on. The demodulator 22
The signal on the signal line 6a is input, demodulated, and the demodulated data is output as a signal 22a.

Reference numeral 24 denotes an HDLC deframing circuit, which receives demodulated data output as a signal 22a,
HDLC-formatted data is zero-deleted, and data before HDLC formatting is output to a signal line 24a.

Reference numeral 26 denotes a temporary memory circuit for temporarily storing encoded image information output to the signal line 24a in frame units. The data correctly received in frame units is output from the temporary memory circuit to the signal line 26a.

Reference numeral 28 denotes an image memory circuit, and the signal line 2
The frame data output to 6a is stored in the corresponding image memory space. Therefore, the image memory circuit 28 needs at least a memory space for storing data of one block. In the present embodiment, when receiving certain partial page information, the previous partial page is output to the signal line 28a and recording is performed. Therefore, a storage memory space for two blocks is used.

If no error has occurred, the bit map of the correctly received frame number is stored in the image memory circuit 2.
8 to a signal line 28b. Also, the signal line 34e
, The signal lines 28b are all set to 0.

The code 30 receives the demodulated data output to the signal line 28a and decodes it by MH (Modified Huffman) decoding or MR (Modified Read).
This is a decoding circuit that outputs the decoded data to the signal line 30a.

Reference numeral 32 denotes a recording circuit that receives a signal output to the signal line 30a and sequentially performs recording for each line.

Reference numeral 34 denotes a control circuit composed of a microprocessor or the like, which performs the following control based on a program described later stored in the ROM 34r.

First, in the pre-procedure, the transmitter stores the minimum scanning time on the receiver side in the mode notified by the receiver. Here, the minimum scanning time of the all white line information is
If it is specified separately (for example, notified by a procedure signal from the receiving side), this is also stored. When transmitting the first partial page, the transmitter counts the number of lines included in the first partial page. Here, the counting of the number of lines is divided into two, that is, the number of all white lines and the number of lines other than all white lines.

The T5 timer after the transmission of the first partial page is set to one minute as specified. When the second partial page is being transmitted, the time required to transmit the partial page is measured, and the number of lines included in the partial page is counted.

Here also, the number of lines is counted separately for the number of all white lines and the number of lines other than all white. Then, after transmitting the second partial page, 1
Find the time to decode and record the partial page.

Here, assuming that decoding and recording are completed for all lines with the minimum transmission time, the time Tn for decoding and recording the nth partial page is as follows: Tn: decoding the nth partial page, Time required for recording SWmin: Minimum scanning time of all white lines LWppn: Number of lines of all white line information of nth partial page SNWmin: Minimum scanning time of lines other than all white LNWppn: nth partial page Tn = Swmin × LWppn + SNWmin × LNWppn
... (1)

Further, the time required for the receiver to decode and record the first partial page is added to the time Tn required for recording sheet cutting, and the transmission time for the second partial page is subtracted from this value. Then, a time obtained by adding a predetermined time (for example, 30 seconds) to the result as a margin is set as the value of the waiting time timer T5 after the transmission of the second partial page.

Thereafter, similarly, after transmitting the nth partial page, the time required for the receiver to decode and record the (n-1) th partial page is added to the time required for cutting the recording paper. Then, the transmission time of the n-th partial page is subtracted from this value, and a time obtained by adding a predetermined time (similarly 30 seconds) as a margin to the result is T5 after the transmission of the second partial page. This is the timer value.

In this manner, the recording capability of the other receiver is estimated from the minimum scanning time of the receiver, and the maximum value of the wait time T5 between the partial pages can be determined based on the estimation result, and the reception state is changed. ECM together
Transmission can be performed.

FIG. 2 shows a control flow of the control circuit 34 for realizing the above control. The illustrated control procedure is stored in the ROM 34r as a control program of the control circuit 34.

In step S42 of FIG. 2, a signal of signal level "0" is output to the signal line 34a, the CML relay of the NCU 2 is turned off, and the line 2a is connected to the telephone 4 side.

In step S44, it is determined whether facsimile transmission has been selected. If facsimile transmission is selected, the process proceeds to step S48, and if facsimile transmission is not selected, other processing (step S46) is performed.

In step S48, the signal line 34a
And outputs a signal of signal level “1” to the CML of NCU2.
With the relay turned on, the line 2a is connected to the facsimile machine side.

Step S50 represents a pre-facsimile communication procedure. Here, since the minimum scanning time of the all-white receiver and the minimum scanning time of the non-all-white of the partner receiver can be obtained from the procedure signal, these values are stored in the memory. Here, when the minimum scanning time for full white is not notified from the partner device, the minimum scanning time for full white is set to be the same as the minimum scanning time for non-full white.

In step S52, it is determined whether the ECM transmission mode has been selected. When the ECM transmission mode is set, the process proceeds to step S58, where ECM transmission is performed. When the ECM transmission mode is not set, image transmission in the normal mode (step S54) and post-procedure (step S56) are performed.

In step S58, 1 is set to a page counter for counting the number of pages being transmitted.

In step S60, a timer is started to measure the transmission time of the page information to be transmitted.

Then, two counters for counting the number of all white lines and the number of non-white lines of the page information to be transmitted from now on are cleared.

[0051] These two counters are
And NWLICTN, the counter WLINTN
Is the number of all white lines, the counter NWLINCTN
Counts the number of lines that are not all white (calculates values corresponding to LWppn and LNWppn in equation (1), respectively).

In step S66, the signal line 10b
Is input, and it is determined whether or not encoding of one line is completed. When the encoding of one line is completed, the process proceeds to step S68. Otherwise, the process proceeds to step S74.

In step S68, the signal line 10c
Is input, and it is determined whether or not the image is all white. If it is not all white, the counter WLICTN is incremented by 1 (step S70).
The counter NWLINKTN is incremented by one (step S72).

In step S74, it is determined whether one page has been read. If the reading of one page has not been completed, the process proceeds to step S66. If the reading of one page has been completed, the process proceeds to step S76.

In step S76, it is determined whether the page counter is 1, that is, whether it is the first page. For the first page, go to step S80.
If it is not the first page, the process proceeds to step S90.

In step S80, the counter WL
The value of INCTN is transferred to the counter WLINCTO. This counter WLINCTO stores the number of all white lines for the next page.

In step S82, the counter NW
LINTN is transferred to the counter NWLINCTO.
This counter NWLINTO stores the number of lines that are not all white for the next page.

In step S84, 60 seconds are set in the T5 timer, and the procedure is performed.

In step S86, it is determined whether or not the document is the last one. If it is the final document, a post-procedure (step S88) is performed, and the process proceeds to step S42.
If it is not the final document, the page counter is incremented by one (step S100), and the process proceeds to step S60.

In step S90, (Swmin of equation (1): minimum transmission time of all white of the partner machine) × counter WL
INCTO (LWppn in equation (1): the number of all white lines in the previous page) + (SNWnin in equation (1): minimum transmission time when the other device is not all white) × Counter NWLINCTO (LNWppn in equation (1): previous page) Is stored in the T5 timer + the time required for cutting the recording paper (for example, 4 seconds)-the measured value of the timer (the transmission time of the currently transmitted page information) + the margin time (for example, 30 seconds). . Also, T
5 The value of the timer should be at least 30 seconds.

In steps S94 and S96,
The counter WLINCTN is transferred to the counter WLINTTO, and the counter NWLINTN is transferred to the counter NWLINTO.

In step S98, step S9
The procedure is performed using the T5 timer obtained at 0.

According to the above configuration, the optimum T5 timer can be set on the transmitter side according to the recording capability of the receiver. Even in the ECM transmission mode, error termination due to timer overflow does not occur. Image transmission and reception can be performed reliably.

In the ECM transmission / reception, the maximum information amount of one partial page is 64 Kbytes, and a device having two memories of this capacity (in the case of the same image memory 28) is known. , These two 6
The 4K-byte memory space is, for example, a buffer 0 and a buffer 1. First, only reception is performed in the buffer 0. Then, while the next partial page is received in the buffer 1, the data in the buffer 0 is decoded and recorded. As a result, even when the cutting operation is performed, the MCF signal can be transmitted in response to the first PPS-Q signal when reception is good for a normal original, but the number of such receivers will increase in the future. It is expected that. For this reason,
It makes sense to determine the wait time between partial pages based on information transmitted one partial page before, as in the above embodiment.

In the above embodiment, the time required for cutting the recording paper is considered to use a fixed value. However, the value notified from the receiver to the transmitter by a procedural signal may be used. In this case, the estimation of the recording capacity on the receiving side becomes more accurate.

In the above embodiment, it is assumed that decoding and recording are completed for all lines in the minimum scanning time. However, the estimation of the recording time of one line from the transmitter may be changed in accordance with the amount of information, image characteristics, compression efficiency, and the like.

[0067]

As described above, according to the present invention,
A means for detecting a minimum scanning time on an image receiving side in a facsimile apparatus having an ECM transmission / reception mode for retransmitting image data based on transmission error detection based on a predetermined communication procedure between a transmitter and a receiver, the minimum scanning time and transmission image data Estimating means for estimating the reception processing time of the partial page on the image receiving side based on the estimating means; and waiting for a procedure signal from the receiving side between the partial pages based on the reception processing time of the partial page on the receiving side estimated by the estimating means. Since the configuration provided with the control means for determining the time is employed, the transmitting side estimates the reception processing time of the partial page of the partner receiver based on the minimum scanning time of the receiver and based on the minimum scanning time. Based on the estimation result, the wait time between partial pages can be determined, Without causing urchin timeout error, there is excellent effect that reliably perform the ECM transmission in accordance with the reception state.

[Brief description of the drawings]

FIG. 1 is a block diagram of a facsimile apparatus according to the present invention.

FIG. 2 is a flowchart illustrating a control procedure of a control circuit of FIG. 1;

[Explanation of symbols]

 2 NCU 4 Telephone 6 Hybrid circuit 8 Reading circuit 10 Encoding circuit 12 Memory circuit 14 HDLC framing circuit 16 V27ter or V29 modulator 18 V21 modulator 19 Addition circuit 20 V21 demodulator 22 V27ter or V29 demodulator 24 HDLC deframing Circuit 26 Temporary memory circuit 28 Image memory circuit 30 Decoding circuit 32 Recording circuit 34 Control circuit

Claims (1)

(57) [Claims] 1. A facsimile apparatus having an ECM transmission / reception mode for retransmitting image data based on transmission error detection based on a predetermined communication procedure between a transceiver and a facsimile apparatus, wherein a minimum scanning time on an image receiving side is detected. Estimating means for estimating the reception processing time of the partial page on the image receiving side based on the transmitted image data, and
A facsimile apparatus, further comprising control means for determining a waiting time of a procedure signal from the receiving side between partial pages based on the reception processing time of the partial page on the receiving side predicted by the estimating means.