JPS6156658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a facsimile receiver capable of detecting a document feeding error on the transmitting side on the receiving side.

Conventionally, when a facsimile transmitter uses a flat scanning method to read a document, the document is moved using a roller or the like, and image signals are processed by reading the document when it crosses a specific point (line segment). However, in such cases, the document may slip and the same area is scanned over and over again, and in that case, the receiving side records a long recording. There are times when almost no data is sent, and in such cases, the receiving side records the blind pattern endlessly. Moreover, in recent years, the number of facsimile machines having functions for sending and receiving absentee calls has increased, so when the above-mentioned malfunction occurs, printing may continue until the recording paper runs out.

The present invention has been made in consideration of the above points, and
The present invention will be described in detail below based on Examples.

FIG. 1 is a block diagram of a facsimile receiver showing an embodiment of the present invention, in which 1 is a terminal for receiving an incoming signal from a line control device connected to a telephone, and 2 is a terminal for signal distortion of the incoming signal. This is an image signal extractor that performs correction, separates the synchronization signal, and extracts the image signal. Line memories 3 and 4 have the capacity to store image signals for one line, and when writing to one line memory, they can be freely read from the other line memory, and data is written to the two line memories alternately. It is controlled by a control circuit (described later) so that it is written. A print register 5 temporarily stores the image signals sent from the line memories 3 and 4, and sends them at an appropriate speed to the printer 6 for printing. A comparator 7 compares one line of the image signal written into one of the line memories 3 and 4 with the image signal read out from the other, and outputs a match signal when they match. 8 is a counter which counts the number of consecutive outputs from the comparator 7, and resets when the output is interrupted for a certain period of time or more. Then, when the count exceeds 40, it outputs an output. Reference numeral 9 denotes a same color determination device that determines whether 99.5% or more of one line is all white or all black. 10 is an AND gate, and 11 is an alarm circuit. 12 is a control circuit for selecting and addressing the line memories 3 and 4 and registers, and processing various alarms.

Next, the operation of the facsimile receiver having the above configuration will be explained. Image information signals (image signals, synchronization signals, etc.) received through a telephone line etc. are introduced into terminal 1 and sent to image signal extractor 2, where only the image signal is extracted and stored in one line memory (for example 4).
sent to. When one line of image signals, that is, one main scanning image signal, is stored in the line memory 4, the next line of image signals is sent to the line memory 3 based on instructions from the control circuit 12. The image signal stored in 4 is sent to a print register 5.
At this time, the image signal sent to the line memory 3 and the image signal output from the line memory 4 are compared by the comparator 7, and if they are completely equal, an output is output.
If they are different, no output will be output. When this image signal transmission is finished, the contents of the print register 5 are transferred to the printer 6.
The line memories 3 and 4 are switched, the third line is sent from the image signal extractor 2 to the line memory 4, and the second line is sent from the line memory 3 to the print register 5. In this way, the image signals are processed sequentially, but if the image signals stored in the line memories 3 and 4 match the output image signals, an output amount is generated from the comparator 7, and the output is If the line continues for 40 lines (equivalent to about 1 cm when the scanning line density is 3.85 lines/mm), it is regarded as an abnormality, and the alarm circuit 11 is activated to call an operator and give an abnormality signal to the control circuit 12. Then, when the 40 lines are deemed to be the same again, the control circuit 12 stops the reception. If only one line out of 40 lines is different in these judgments, that line is considered to be a transmission error and the counter 8
is not reset. In addition, when the original has blank spaces (that is, white background transmission), and when it is a photograph, etc., the same image signal is 1.
Since the lines are often the same over cm or more, it is considered normal for the image signal to be considered to have ruled lines in all white, all black, and all white. Therefore, if 99.5% or more of the image signals for one row are the same color, the same color determining unit 9 outputs an "L" output, closes the AND gate 10, and ignores the output of the counter 8.

FIG. 2 is a block diagram of a facsimile receiver according to another embodiment of the present invention. In the case of FIG. Take for example. 20 is a terminal for receiving signals as in FIG. 1, 21 is an image information extractor that extracts an encoded image signal (hereinafter referred to as image information) from the received signal, and 22 is a terminal that extracts the image information extracted by the image information extractor. It is buffer memory that is temporarily stored. Reference numerals 23, 24, and 25 are line memories each storing one row's worth of image signals, and 26 and 27 are multiplexers. Reference numerals 28 and 29 are a decoding line address counter and a reference line address counter (when encoding is two-dimensional), respectively, when image information is decoded into an image signal. 30 is a print register, and 31 is a change point detection circuit. Reference numeral 32 denotes a comparison circuit for determining whether image signals for one row match, and also includes a line memory for one row. 33 is a control circuit, and 34 is an alarm circuit.

First, the flow of image information and image signals in this configuration will be explained. The received signal is introduced from a terminal 20, subjected to distortion correction by an image information extractor 21, separated from other signals, and then introduced to a buffer memory 22.
The image information (code example) stored in the buffer memory 22 is called with a specific clock, a decoded binary signal (image signal) is obtained by referring to a decoding table (not shown), and the decoded binary signal (image signal) is sent through the multiplexer 26. Write to one of the line memories 23, 24, and 25. This is written cyclically line by line to the next line memories 24, 25, 23 as in the case of FIG. send a signal. By the way, this is the case of a one-dimensional encoded signal, but when decoding a two-dimensional signal,
A change point detection circuit 31 detects a change point from black to white or white to black from the contents of a line memory to be a reference line, and the detected point is guided to a control circuit and used for decoding. Since decoding, reference, and writing/reading to each line memory are all controlled by a predetermined clock, the line memories 23, 24, and 25 are controlled by a decoding line address counter 28 and a reference line address counter 29. advance.

When receiving signals from the buffer memory 22 to the multiplexer 26, the control circuit 33 counts and compares the number of white signals and the number of black signals included in the signal from the image information or image signal, and determines whether most of them are of the same color. . This corresponds to the same color determiner described above, but since it is an example of the image signal code, it marks the decoding table for all white (or all black and similar) and determines whether that decoding table has been referenced. It is easy to judge if you keep an eye on it. If the color is not the same, every 200 lines (scanning line density is
3.85 lines/mm, equivalent to approximately 5.2cm)
send a signal to. In response to this signal, the comparator circuit 32 takes in the image signal for one line that is about to be output from the multiplexer 27 to the print register 30 into the built-in line memory, and then passes it through the multiplexer 26 to determine whether it is going to be written into the line memories 23 to 25. The image signal for one row is compared. If the two are different, the comparison circuit 32 ends the comparison operation, but if they are equal, it sends a match signal to the control circuit 33. Upon receiving the coincidence signal, the control circuit 33 generates a signal without waiting for the next 200 rows and compares again to determine whether or not the coincidence is a coincidence. When a matching signal is received again, it is considered abnormal and the alarm circuit 3
4, the operator is notified or the reception is interrupted.

That is, in the example shown in Figure 1, each line is compared and if the same image is longer than a certain length, it is considered abnormal, whereas in the example shown in Figure 2, each line is compared continuously and if the same image is the same, it is considered abnormal. . In both cases, the detection interval (1 cm for the former and 5.2 cm for the latter) should not be an integral multiple of the normally written character size (5 mm to 8 mm) or the ruled line interval (approximately 7 mm).

As described above, the present invention includes a memory circuit that records an image signal for one line from an incoming signal, and an image signal for n lines after the image signal stored in the memory circuit (where n is a natural number) and the image signal that is stored in the memory circuit. This facsimile receiver is equipped with a comparator that compares the original image signal and an alarm means that issues an alarm when the comparator determines that the two match, so it is easy to detect when the original slips on the transmitter side. It can be used to alert you.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a facsimile receiver according to one embodiment of the present invention, and FIG. 2 is a block diagram of a facsimile receiver according to another embodiment of the present invention. 1, 20... terminal, 2, 21... image signal (image information) extractor, 3, 4, 23, 24, 25... line memory, 5, 20... print register, 7, 22
... Comparator (circuit), 8 ... Counter, 9 ... Same color determiner, 11, 34 ... Alarm circuit, 12, 3
3...control circuit, 26, 27...multiplexer.

Claims (1)

[Claims] 1. A memory circuit that extracts and stores image signals for one line from the transmission signal from a facsimile transmitter that sequentially sends and reads the transmitted original and transmits the read image signals, and a printer that records based on the contents of the memory circuit. and comparing means for comparing the image signal of n rows after the image signal stored in the storage circuit (where n is a natural number) with the image signal stored in the storage circuit, and transmitting when the comparison means detects a match between the two. A facsimile receiver comprising a control means that determines that there is an abnormality in document feeding and interrupts reception and recording, and an alarm means that issues an alarm.