JP2812363B2 - Document reading device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile, a scanner, and the like for reading a document provided with a document position detecting function for detecting a position in the sub-scanning direction of a document placed on a lattice-patterned carrier sheet. Related to the device.

2. Description of the Related Art Conventionally, in a facsimile, a document is sandwiched on a transparent carrier sheet, a symbol indicating a transmission portion of the document is written on the carrier sheet, and only the designated portion is read and transmitted by recognizing the symbol. A known example is known (see, for example, JP-A-63-2459).

However, this method has a problem that a symbol indicating a transmission portion must be written on the carrier sheet.

In a facsimile, scanner, or the like, a document is placed on a document moving table having a predetermined pattern, and the carrier sheet is set at a reading position, thereby automatically detecting the document position and reading the document. Is also known. In this device, usually, as shown in FIG.
A pattern in which only the straight lines 2 extending in the sub-scanning direction are arranged at regular intervals is formed on the document moving table 1, and the document 3 is placed on the pattern. The reading unit performs scanning in the main scanning direction. During the relative movement in the sub-scanning direction, a pattern consisting of straight line 2 is first read in the main scanning direction in a portion where there is no original, and the pattern is detected. Since the detection is no longer performed, the position is set as the start position of the reading range, and when the reading unit comes to the document end position, the specific pattern is detected again.

However, according to such a configuration, in order to detect the document arrangement range in the sub-scanning direction, a pattern recognizable in the main scanning direction needs to be formed over the entirety in the sub-scanning direction. There is. Therefore, as shown in FIG. 4, a pattern consisting of only straight lines extending in the sub-scanning direction must be used. In such a pattern, when the document is placed on the pattern, the document is neatly placed at a desired position. Difficult to put. In order to place a document neatly and at a desired position, it is preferable to use a carrier sheet having a lattice pattern. However, if a carrier sheet having such a lattice pattern is used, the leading edge of the document cannot be detected. There was a problem.

The above problem arises for the following reasons. That is, in the case of a lattice pattern, since there is a straight line extending in the main scanning direction, the straight line cannot be distinguished from the document, and thus the straight line in the main scanning direction is erroneously detected as the leading edge of the document. , The leading edge of the original could not be reliably detected.

The present invention has been made in view of the above problems, and can automatically detect and read an original placed on a carrier sheet having a lattice pattern optimal for arranging the original. It is an object of the present invention to provide an original reading apparatus.

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-described problems, and as a result, while reading a line in the main scanning direction, a predetermined pattern cannot be detected. When the main scanning passes through the line for about 10 times and exceeds the number of lines corresponding to the thickness of the line, a predetermined pattern can be detected again. When a predetermined pattern cannot be detected even when the number of lines exceeds the corresponding number, it can be detected that the reading of the document has been started, and the reading signal is output retroactively to thereby detect the entire range of the document. Have been found, and the present invention has been completed. That is, according to the present invention, a carrier sheet having a lattice pattern and a reading unit for main-scanning a document thereon and converting it into an electric signal, and a drive for relatively moving the reading unit and the document in the sub-scanning direction An apparatus; a pattern recognizing means for determining whether a signal of one line in the main scanning direction from the reading means is a predetermined pattern; a storage means for storing a signal of a predetermined number of lines from the reading means; Document determining means for continuously counting non-pattern recognition signals sent from the recognizing means and determining that the document is a document when the number exceeds a predetermined number; receiving the document determining signal from the document determining means; And a data output device for transferring data from a signal before a predetermined number of lines stored in the device to an external device or the like.

According to the present invention, the reading means recognizes a predetermined pattern by a pattern recognition circuit in a portion other than a line in the main scanning direction while the reading unit is reading a pattern on the carrier sheet, and reads the pattern on a line in the main scanning direction. Although the predetermined pattern cannot be recognized, the predetermined pattern is recognized again when the number of lines corresponding to the thickness of the line elapses. However, when the reading means reaches the document position, the pattern recognition circuit cannot detect a predetermined pattern continuously even if it exceeds a predetermined number (the number of lines corresponding to the line thickness in the main scanning direction). In this case, the document determination means determines that the document is a document, and a signal of a predetermined number of lines before stored in the storage means can be transferred to an external device or the like via a data output device via a data output device. , The position of the document can be detected and the document can be read from the first position.

Embodiment FIG. 1 is a block diagram showing a schematic configuration of a document reading apparatus according to an embodiment of the present invention. Reference numeral 5 denotes a carrier sheet set at a predetermined position of the document reading apparatus. It is a manuscript loaded. As shown in FIG. 2, the carrier sheet 5 has a lattice pattern having lines 7 in the main scanning direction and lines 8 in the sub-scanning direction. Normally, other portions of the carrier sheet 5 are black, and portions of the lines 7 and 8 are white. Carrier sheet 5 with lattice pattern
Is preferable because the position of the original 6 can be easily determined when the original 6 is placed thereon.

In FIG. 1, reference numeral 10 denotes a reading unit such as an image sensor that scans the carrier sheet 5 and the original 6 on the carrier sheet 5 and converts them into electric signals. The reading means or the original 6 is moved in the sub-scanning direction by a driving device (not shown). Reference numeral 11 denotes an image data input terminal for inputting an output signal from the reading unit 10, reference numeral 12 denotes a pattern recognition circuit for determining whether or not a signal of one line in the main scanning direction is a predetermined pattern;
Is a line memory circuit that stores signals sent from the reading means 10 for a predetermined number of lines.14 is a signal that indicates that a pattern is not a pattern from the pattern recognition circuit 12, that is, when a non-pattern recognition signal is continuously sent out. The document determination circuit 15 counts the number and determines that the document is a document when the number exceeds a predetermined number n. The document determination circuit 15 outputs the image data signal of the line memory circuit 13 in accordance with the document detection signal from the document determination circuit 14 to the recording unit. , An image data output I / F unit for transferring data to an external device such as a transmission unit; and 16, an image data output terminal. Here, the predetermined number n serving as a criterion for judging an original in the original judging circuit 14 is 2 in view of the margin of the number of main scanning lines corresponding to the thickness of the line 7 extending in the main scanning direction on the carrier sheet 5. ~
The number is calculated by adding three lines. The number of data lines that can be stored in the line memory circuit 13 is also set equal to the predetermined number n. The pattern recognition circuit 12 outputs a pattern recognition signal when the signal of one main scanning line matches the pattern of the line 8 extending in the sub-scanning direction shown in FIG. It is configured to output a non-pattern recognition signal.

Next, the operation of the document reading apparatus having the above configuration will be described. The reading means 10 relatively moves in the sub-scanning direction while scanning the carrier sheet 5 and the original 6 thereon, and outputs image data to the image data input terminal 11. The image data input from the input terminal 11 is sent to the pattern recognition circuit 12 and the line memory circuit 13 at the same time, and the line memory circuit 13 stores the latest n lines of image data. The pattern recognition circuit 12 determines, for each input data of one main scanning line, whether or not the data is a predetermined pattern. For example, in FIG. 2, when a position where there is no line 7 in the main scanning direction is scanned as indicated by an arrow A, one line of data corresponds to a predetermined pattern, and a pattern recognition signal is output. However, as shown by arrow B or arrow C,
When the upper side is scanned, a non-pattern recognition signal is output because the data of one line does not correspond to a predetermined pattern. The document determination circuit 14 counts the non-pattern recognition signal sent from the pattern recognition circuit 12, and when the non-pattern recognition signal continuously exceeds a predetermined number n, determines that the document is a document and outputs the document detection signal. It is sent to the image data output I / F unit 15.
The image data output I / F unit 15 receives this signal and starts sending out the image data stored in the line memory circuit 13 from the image data output terminal 16. Here, the document determination circuit
When the document 14 is detected, the document actually starts from n lines before it. However, since the latest n lines of image data have been stored in the line memory circuit 13, the image data output terminal 16 Is sent from the leading edge of the document, and is read from the leading edge of the document.

When reading by the reading means 10 proceeds and the reading means 10 passes the rear end of the document, the reading means 10 reads the carrier sheet 5 and the pattern recognition circuit 12 outputs a pattern recognition signal again. The document determination circuit 14 receives this signal to determine the end of the document, and the image data output I / F unit 15 receives the signal and outputs n lines of image data thereafter, and ends the image data transfer. As a result, reading is performed up to the rear end of the document.

In the above operation, if the leading end of the document 6 is on the line 7 in the main scanning direction of the carrier sheet 5, it is determined that the document is from the start position of the line 7 and the line 7 is read. Becomes However, in practice, the thickness of the line 7 is usually about 0.5 mm, and the leading end of the document is rarely positioned on the line 7 and the line 7 is white. There is not much trouble.

Next, a specific example of the document determination circuit 14 will be described with reference to FIG. In FIG. 3, 17 is an input terminal for a pattern recognition signal and a non-pattern recognition signal from the pattern recognition circuit 12, 18 is a synchronization signal input terminal for each line, 19 and 20 are flip-flop circuits, and 21 is an OR. Circuit, 22 is a counter circuit that outputs a signal when counting a predetermined number n,
23 is a flip-flop circuit, and 24 is a document reading start signal output terminal. An output signal from the pattern recognition circuit 12 is input from an input terminal 17 to a flip-flop circuit 19. A synchronizing signal output for each line is input to the flip-flop circuit 17 via the input terminal 18 as a clock. Therefore, if a non-pattern recognition signal comes, it is latched. The latch circuit 20 is also latched. When the non-pattern recognition signal is latched by the flip-flop circuit 19, the output of the OR circuit 21 is turned on,
The clearing of the counter circuit 22 is released, and how many lines the state continues is counted. When the count value becomes equal to or greater than a predetermined value n, a document detection signal is output from the counter circuit 22 to the flip-flop circuit 23 and latched there, and the signal is output to a document reading start signal output terminal. twenty four
Output from

Here, the non-pattern recognition signal is counted by the counter circuit 22. In consideration of a case where a pattern similar to the base (pattern of the carrier sheet) partially exists in the original, the non-pattern recognition signal is counted during the counting. If a pattern recognition signal arrives at the input terminal 17 for one line, it is ignored and the counter circuit 22 continues counting. After reading the line 7 in the main scanning direction of the carrier sheet 5,
Only when a pattern recognition signal is received continuously for more than lines, an off signal is input to the counter circuit 22 and the counter circuit
22 is cleared. The flip-flop circuit 20 and the OR circuit 21 fulfill this function.

EFFECT OF THE INVENTION As is apparent from the above description, the present invention provides a pattern recognition method for reading an original placed on a carrier sheet having a lattice pattern and determining whether each read line has a predetermined pattern. Circuit, and a document determining unit that counts non-pattern recognition signals continuously sent from the pattern recognition circuit and determines that the document is a document when a predetermined number is exceeded. A storage means for detecting the leading end of the original, storing read data of a predetermined number of lines, receiving a document determination signal from the original determination means, and storing a predetermined number of lines stored in the storage means. By providing a data output device for transferring data from a previous signal to an external device or the like, it is possible to transmit image data from a starting point of a document. This has the effect that the position of the original can be automatically detected while using a carrier sheet having a preferable lattice pattern as the base of the original, and the original can be read from the first position.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a document reading apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing a carrier sheet and a part of a document used in the embodiment, and FIG. FIG. 4 is a block diagram showing a specific example of a document judging circuit in the embodiment, and FIG. 4 is a plan view showing a carrier sheet and a part of a document conventionally used. 5 ... Carrier sheet, 6 ... Document, 7 ... Line in main scanning direction, 8 ... Line in sub scanning direction, 10 ... Reading means, 11 ...
Image data input terminal, 12 ... pattern recognition circuit, 13 ...
Line memory circuit, 14 original document judgment circuit, 15 image data output I / F section, 16 image data output terminal, 17 signal input terminal from pattern recognition circuit 12, 18 synchronous signal input terminal , 19, 20 ... flip-flop circuit, 21 ... OR circuit, 22 ... counter circuit, 23 ... flip-flop circuit, 24 ... signal output terminal.

Claims (1)

(57) [Claims] 1. A carrier sheet having a lattice pattern, reading means for scanning a document on the carrier sheet in the main direction and converting it into an electric signal, and a driving device for relatively moving the reading means and the document in the sub-scanning direction. Pattern recognition means for determining whether a signal of one line in the main scanning direction from the reading means is a predetermined pattern, storage means for storing a signal of a predetermined number of lines from the reading means, A non-pattern recognition signal continuously transmitted from the means is counted, and a document determining means for determining that the document is a document when a predetermined number is exceeded, and a document determining signal from the document determining means,
A document reading device having a data output device for transferring data from a signal before a predetermined number of lines stored in the storage means to an external device or the like;