JPS581822B2 - Kogakumojiyomitorisouchiniokeru Mojikiridashiboshiki - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an optical character reading device that optically reads characters written on a form, and particularly for characters written larger than a predetermined size or two or more characters written in a row. The present invention relates to a character extraction method that optically scans and extracts characters.

Generally, devices for optically reading handwritten characters have a complicated mechanism.

Even if restrictions are placed on the writing method, such as a writing frame, there are various ways in which the person filling in the information may write outside the writing frame, or fill in letters consecutively.

Therefore, it is necessary to cut out the characters written on the form one by one.

Conventionally, in order to recognize character patterns, this type of optical character reading device optically scans the characters written on a form, converts the character information into electrical signals, and then adds a function to cut out character information one character at a time and performs preprocessing. The start of the character pattern is detected in the section, and characters are cut out according to the end of the character pattern or the maximum number of scans.

However, in such optical character reading devices,
When the maximum number of scans is reached, character extraction ends even if the end of the character is not reached.

Therefore, if a character is larger than the specified size or two or more characters are written in a row, the character will be cut out at the maximum number of scans, not at the end of the character. In this case, the part cut out by the maximum number of scan lines and the remaining part are separated, so to speak, and cut out is performed as two characters, resulting in the number of cut out characters being greater than the number of written characters.

For this reason, the character recognition unit in the next stage discriminates between the part cut out with the maximum number of scans and the remaining part, but there is no guarantee as to what kind of characters the remaining part will be. reading errors often occur.

Also, if two or more characters are entered in a row,
Since characters are cut out according to the maximum number of scan lines, there is a gap between the written characters and the cut out characters, and the number of cut out characters is greater than the written characters, and the character recognition unit may be misread.

For this purpose, a writing frame is provided on the form, characters are written in the writing frame, the writing frame and the characters written in the frame are detected separately, and character information is extracted based on the signal from the writing frame. There is a method that does this, but in this method, the entry frame and the characters must be recognized separately, requiring two detection devices for the entry frame and the characters, and mechanically.
In addition to being structurally complex, the optical character reading device itself has the disadvantage of being expensive.

The purpose of the present invention is to overcome the drawbacks of the prior art as described above. Even if a character is larger than a predetermined thickness or two or more characters are written in a row, appropriate character extraction is performed, and a character writing frame detection device as in the prior art is particularly required. It is an object of the present invention to provide a character extraction method in an optical palm character reading device that can be achieved at a relatively low cost.

In order to achieve the above object, the present invention uses optical scanning,
A plurality of pattern registers are provided that sequentially capture character patterns converted into telegram signals, and means for detecting the start and end parts of characters corresponding to these pattern registers is added, and the count is performed for each scan. If the end of a character is not detected even though the value of the scan counter that is updated has reached the maximum number of scans, a dummy scan flag is set, and the dummy scan counter that is incremented every scan is set to a certain value. Perform dummy scanning until the start of the next character is detected, cut out a character pattern based on at least the maximum number of scans, and check that the number of cut out characters is greater than the number of characters recorded on the form. This prevents errors in cutting out characters.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

First, an optical character reading device to which the present invention is implemented will be described.

FIG. 1 is a block diagram showing each part of the optical character reading device.

Reference numeral 12 denotes a form feeding mechanism section which sequentially feeds out forms one by one from the hopper for reading.

Reference numeral 13 denotes a reading head unit that optically scans the form sent out from the form feeding mechanism unit 12, reads characters, and converts the read characters into electrical signals. Reference numeral 14 indicates character information converted into electrical signals. 15 is a preprocessing unit that extracts characters one by one from , normalizes the character position, and removes noise.
A character recognition unit 16 identifies normalized characters, and a data check unit 16 checks whether the read data is correct.

Reference numeral 11 denotes a control section for controlling each of the above-mentioned sections.

With reference to FIG. 2, the optical character reader will be more clearly understood.

The read head section generally includes a laser transmitter 21, a vertical mirror 22, a lens 23, a horizontal mirror 24, and a photomultiplier tube 2.
6.

The light emitted from the laser transmitter 21 is reflected by the vertical mirror 22 and scanned in the vertical direction.

The light passes through the lens 23 and passes through the horizontal mirror 24.
The form 25 is scanned in the horizontal direction.

FIG. 3 shows the situation in the scanning direction.

In FIG. 3, S is the start of a character and E is the end of the character.

The character portion of the light reflected from the form 25 after being scanned in this manner is detected by the photomultiplier tube 26, converted into an electrical signal, and sent to the preprocessing section 14 (FIG. 1) as a binary signal.

In the preprocessing section 14, characters are extracted one character at a time from the character information converted into electrical signals.

Regarding this, it will be easily understood from the following explanation that character extraction, which is characteristic of the present invention, is performed.

The character extraction method according to the present invention will be explained with reference to FIG.

In the figure, a reading head unit 41 optically scans characters written on a form, converts character information into electrical signals,
Create a binary character pattern signal.

The binarized character pattern signals are sequentially transferred to the pattern register 42.

Next, the start of a character is detected by the character start logic 43 of the mask logic on the pattern register 42, and the character pattern is sequentially transferred to the character recognition logic 46.

Thereafter, when the end of the character is detected in the character end logic section 44 of the mask logic, a signal is issued from the character end logic section 44 to the character recognition logic section 46 so that the character pattern can be transferred to the character recognition logic section 46. will be stopped.

This means that the extraction of one character is completed, and the character recognition logic unit 46 recognizes the extracted character.

When optically scanning characters on a form, the maximum number of scan lines is predetermined, but if the character end logic unit 44 does not detect a character end even though the maximum number of scan lines has been reached, a dummy Scanning logic 45 stops the transfer of character patterns to character recognition logic 46 .

At the same time, the transfer of the character pattern to the character recognition logic unit 46 is also stopped when a character start is detected.

If the dummy scanning logic unit 45 does not detect the end of a character, it continues scanning, and when the end of a character is detected at this time, the character start logic becomes valid for the first time.
Character cutting begins again.

The present invention will be explained in more detail based on FIG.

In the figure, pattern register 51 consists of three pattern registers 511, 512, and 513.

Of course, the number of registers is not limited to three, but may be four or . In general, a plurality of registers such as five registers may be used.

Three flip-flops I1, 12, 13, 21, from the beginning of each pattern register 511, 512, 513,
23, 31, 32, and 33 are for detecting the start of a character and the end of a character.

Corresponding to optical and optical scanning, the binarized character patterns are sequentially taken in from the beginning of the pattern register 51 while being shifted in the direction of the arrow α.

Therefore, if there is a character start part, the character start is detected by the three flip-flops at the beginning of each register.

Of course, even in the case of the end of a character, the end of the character is always detected because it passes over this flip-flop while being shifted.

The three flip-flops at the beginning of each pattern register 511, 512, 513 are for detecting the start and end of a character, and it is appropriate to have a plurality of flip-flops in consideration of noise removal and the like.

The character start and character end signals detected by flipflops 11-33 enter mask logic 56.

Inputs 11 to 33 of the mask logic 56 serve as input terminals.

When a character start is detected, a character start flag 53 is set, and when a character end is detected, a character end flag 52 is set.

The scanning counter 55 is a counter that starts a counting operation in response to a signal from the character start flag 53 when a character start is detected, and counts up by 1 each time the form is scanned in the vertical direction.

The memory 54 is a storage device that stores character patterns;
When a character start is detected, character patterns are sequentially taken into the pattern register 51 for each scan and are stored in the pattern register 51.

The maximum number of scans register 57 is a register that stores the maximum number of scans perpendicularly scanning one character on a form, and the signals from this maximum number of scans register 57 and the scan counter 55 are sent to an AND gate 501. It's in.

That is, when the value of the scan counter 55 reaches the maximum number of lines to be scanned, the output signal of the AND gate 501 is applied to the character end flag 52 and the dummy scan flag 59.

Of course, if the end of a character is detected by the mask logic 56 before the value of the scan counter 55 reaches the maximum number of scans, the counting operation of the scan counter 55 is stopped and the entire character pattern for one character is loaded into the memory 54. It will be done.

Finally, if the value of the scan counter 55 is equal to the value of the maximum scan number register 57 without the character end being detected,
A dummy scan flag 59 is set and a dummy scan counter 58 is cleared.

After this, dummy scanning is performed.

Dummy scanning is normally performed on characters written outside the character entry frame or characters written consecutively.

The number of dummy scans is stored in advance in the dummy scan register 60, and the dummy scan counter 58 is sequentially counted up for each scan.
When the values in the dummy scan register 60 and dummy scan register 60 match, the dummy scan flag 59 and the character start flag 53 are reset by the output of the AND gate 502.

Of course, even if the end of a character is detected before the value of the dummy scan counter 58 reaches the value of the dummy scan register 60, the dummy scan flag 59 is reset.

Next, the operation of the character cutting force type according to the present invention will be explained.

Character times (shaded areas in Figure 5) are written in the character entry frame on the form, and the maximum number of scans required to cut out one character is 25, and the number of dummy scans is 3.

In this case, the maximum number of lines to be scanned is set based on how many lines are required to scan a character entry frame for one character to cut out one character.

First, by optically scanning a form, a character pattern enters the pattern register 51 sequentially to the left or to the right in the direction of arrow a for each register.

When a character start is detected in flipflops 11 to 33 of each register 511, 512, 513, a character start flag 53 is set by mask logic 56.

At this time, the counting operation of the scan counter 55 is started, and the counter 55 counts up for each scan, and the scanned character pattern is sequentially transferred from the pattern register 51, particularly the pattern register 513, to the memory 54.

When the end of a character is detected by the mask logic 56, the character end flag 52 is set, and the transfer of the character pattern for one character to the memory 54 is completed.

Therefore, in this case, normal character extraction was performed.

However, when the value of the scan counter 55 reaches the value of the maximum scan number register 57, that is, 25 lines, without the character end being detected, the scan counter 55 and the maximum scan number register 57 match, and the dummy scan flag 59 is set.

As a result, the dummy scan counter 58 is reset to the initial value and counts up every dummy scan.

Here, during dummy scanning, the dummy scanning flag 5
If 9 is set, the character pattern in the pattern register 51 will not be transferred to the memory 54 even if the character start flag 53 is set.

During this time, if the mask logic 56 detects the end of a character, the character end flag 52 is set and the second
Character patterns up to five scans are cut out.

After that, preparation is made to detect the start of the next character.

During the dummy scan, the end of a character is not detected, and the value of the dummy scan count 58 is the value of the dummy scan register 60, that is, "
If the number matches 3'', the dummy scan flag 59 is reset.

At this time, character patterns up to the 25 scanned lines are cut out.

Thereafter, provision is made to detect the start of the next character.

Characters cut out in this way are shown in FIG. 6b or 6d.

Incidentally, ajC indicates character cutting according to the conventional technique, and for a to d, the characters in the upper row show before cutting out, and the characters in the lower row show after cutting out.

In the character cutout method according to the present invention, even when the value of the scan count 55 reaches the maximum number of scans, the character pattern taken into the pattern resist during dummy scanning is treated as noise and removed.

For example, while a in the figure is cut out as three characters, b is completely separated into two characters and cut out.

When the end of a character is detected during gummy scanning as shown in d, the extraction of one character ends here.

In this case, the character patterns stored in the memory 54 are the character patterns cut out until the maximum number of scanned lines reaches 25.

Thereafter, when the start of the next character is detected, the next character is cut out in the same manner as described above.

Also, as shown in b, if the end of a character is not detected during dummy scanning and the value of the dummy scanning counter 55 reaches the value of the dummy scanning register 60, that is, 3 lines, the end of the dummy scanning becomes the start of the next character. In this case as well, the character patterns cut out until the maximum number of scanned lines reaches 25 are stored in the memory 54.

In this type of character extraction method, even if a character is written outside the character entry frame (Fig. 6 d), after one character is extracted according to the maximum number of scans, the portion remaining after character extraction is In order not to import up to three images into the memory 54 by dummy scanning,
Unlike in the past, the number of characters cut out is not greater than the number of characters written, and even if a character pattern is cut out, if it is less than three, it will be treated as noise, making it extremely unlikely that a character will be cut out incorrectly. becomes less.

In addition, even in cases where two characters are written consecutively beyond the character entry frame (Figure 6b), characters are cut out by dummy scanning, and there are more characters cut out than written characters. That will no longer be the case.

Furthermore, even if a text entry frame is provided for the person filling out the form,
No special means such as a character entry frame detection device is required for character extraction.

In the above embodiment, even if the end of a character is detected during dummy scanning, the characters are cut out until the maximum number of scans is reached. However, if the end of a character is detected during dummy scanning, (FIG. 6d), it is also easy to cut out from the start of the character to the end of the character detected during dummy scanning.

By doing this, recognition errors in the next stage of character recognition are considerably reduced.

Furthermore, in the above embodiment, the pattern register 51 is
Although a case has been described in which three flip-flops are provided for each pattern register to detect the character scoot and the character end, the present invention is not limited to this, and the present invention is not limited to this. The number of flip-flops for detecting the start character end may be set appropriately.

Furthermore, the value of the register 5γ where the maximum number of scan lines is set according to the size of the character entry frame can be changed, or the value of the register 60 where the dummy number of scan lines can be set according to the interval of the character entry frame can be changed as appropriate. is also easy.

By doing this, character extraction can be performed with considerable versatility.

As described in detail above, according to the present invention, by performing dummy scanning even for characters written beyond the character entry frame, it is possible to prevent the number of cut out characters from becoming more than the written characters. In addition, it is possible to cut out characters at low cost and with good performance.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of an optical character reading device. FIG. 2 is a diagram showing the optical scanning and reading section. FIG. 3 is a diagram showing the optical scanning direction. FIG. 4 is an explanation of character cutting according to the present invention. FIG. 5 is a schematic block diagram of a preprocessing unit used for explaining character extraction according to the present invention, and FIG. 6 is a diagram showing a preprocessing unit used for cutting out continuous characters and large characters. In the figure shown, a and C are conventional examples, b,
d shows an example according to the present invention. Explanation of symbols, 51...Pattern resist, 52
...Character end flag, 53...Character start flag, 54...Memory, 55...
...Scanning counter, 56...Mask logic, 5
7...Maximum scanning number register, 58...
- Dummy scan counter, 59...Dummy scan flag, 60...Dummy scan register.

Claims (1)

[Claims] 1. In an optical character reading device that optically scans a form multiple times in a predetermined direction and reads characters written on the form,
A plurality of pattern registers that sequentially capture character patterns that have been optically scanned and converted into electrical signals, and means for detecting a start part and an end part of one character provided corresponding to each of the pattern registers. , a scanning counter that updates its count value every time it is scanned once the start part is detected and counts up to a certain value; and even if the counter reaches a certain value, the end part of the character is not detected. Sometimes, a dummy scan is performed and a dummy scan counter is provided whose count value is updated every time the dummy scan is performed, and even if the count value of the dummy scan counter reaches a certain value, the end part of the character is not detected. In this case, the character cutting method is characterized in that the character pattern is cut out corresponding to scanning up to a certain value counted by the scanning counter.