JPH0327487A - Optical character reading device - Google Patents

Abstract

PURPOSE:To shorten time required for reading a business form by limiting the detecting range of the left end of the business form according to the detected result of a detecting means to detect the position and the size of the business form. CONSTITUTION:When the existence of the business form 10 is detected by the detecting means 71, and in addition, the existence of the business form 10 is not detected by the detecting means 72, the left end of the business form 10 is positioned at the left side of the position of the detecting means 71. Therefore, the detection of the left end of the business form 10 needs to be executed only in the range between x11 and x12. Thus, the range in which the left end of the business form 10 is detected by a photoelectric converting part 1 is limited according to the detected state of the business form 10 by the detecting means 71 and 72. Thus, the time required for reading the business form 10 by the photoelectric converting part 1 can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical character reading device that can quickly detect the edge of a form to be read.

(Prior Art) FIG. 2 is a block diagram showing the configuration of a conventional optical character reading device.

The illustrated device includes a photoelectric conversion means 11, a binarization means 6,
It consists of a binary data storage means 7, a control section 8, a recognition section 9, etc.

The photoelectric conversion means 11 includes a photoelectric conversion section 1 , a light source 2 , a condensing lens 3 , a transport mechanism 4 , and a multi-value data storage means 5 .

The photoelectric conversion unit 1 is composed of a line sensor and the like, and performs photoelectric conversion of data on the form 10, and converts this data into a gradation digital signal.

The light source 2 is a linear light source, and is located at a predetermined position P on the form 10.
It is something that illuminates.

The condensing lens 3 guides a light image on the form 10.

The transport mechanism 4 is for transporting the form 10 in the direction of the arrow 4A. This transport mechanism 4 is controlled by a control section 8.

The multivalued data storage means 5 is made up of a RAM (random access memory), etc., and temporarily stores the multivalued data sent from the photoelectric conversion section 1. This multivalued data storage means 5 has a capacity to store all data on the form 10.

The binarization means 6 reads out the multi-value data stored in the multi-value data storage means 5 and converts it into binary data of O or 1.
It is stored in the value data storage means 7.

The binary data storage means 7 is for storing the binary data sent by the binarization means 6.

The control section 8 controls the reading of the photoelectric conversion section 1 in the main scanning direction via the multi-value data storage means 5, and controls the conveying mechanism 4 in the sub-scanning direction. . The control unit 8 stores a form format that specifies the size of the form, the length of the form, and the position where characters are written. A position P indicates a position where the photoelectric conversion unit l receives reflected light from the light source 2 via the condensing lens 3. Further, the control unit 8 determines the position to be read based on the document format, and determines the position to be read from the amount of conveyance sent from the conveyance mechanism 4. Then, an instruction is given to write the gradation digital data sent from the photoelectric conversion section 1 into the multi-value data storage means 5.

In this writing procedure, first, the control unit 8 scans the photoelectric conversion unit 1 in the direction of the arrow 1A, that is, in the main scanning direction, as shown at position P, and stores one line of gradation digital data in the multi-value data storage means. Write in 5. Next, the control unit 8 causes the transport mechanism 4 to scan the form 10 by one pixel in the direction of the arrow 4A. Then, the control unit 8 controls the photoelectric conversion unit 1 by the arrow 1A.
Repeat the main scan in the direction. The control unit 8 performs the above scanning for all positions on the form 10 to be read.

The gradation digital data stored in the multivalued data storage means 5 is converted into binary data of O or 1 by the binarization means 6 and stored in the binary data storage means 7. The recognition unit 9 specifies a threshold value when converting the gradation digital data into binary data.

FIG. 3 is a diagram showing the storage state of binary data in the binary data storage means 7. As shown in FIG.

The left end 25 indicates the maximum left end position at which the photoelectric conversion unit 1 can perform main scanning. Further, the right end 26 indicates the maximum right end position at which the photoelectric conversion unit 1 can perform main scanning.

On the other hand, the left end 21 of the form indicates the left end of the form 10. Also,
The right end 22 of the form indicates the right end of the form IO.

Note that an arrow X in the figure indicates the main scanning direction on the form 10. Further, the arrow y in the figure indicates the sub-scanning direction on the form 10, that is, the direction opposite to the transport direction of the form.

Any position on the binary data storage means 7 in FIG. 3 is represented by coordinates (x, y). Y is the center position of the form 10 in the sub-scanning direction. , the leftmost 25 X addresses are xffiIn
, the rightmost 26 X address x. ．． l. Let it be X. Here, Xm+n<Xmax.

In order to find the position of the left end 21 of the form, it is first checked whether the white border at the left end of the form 10 has a width greater than a predetermined width. When the white part of the edge is wider than a predetermined width, the left edge of the edge is set as the left edge 21 of the form.

More specifically, the number of consecutive white pixels in the X direction in FIG.
Set to 1.

FIG. 4 is a flowchart showing the processing procedure for determining the left edge of a form.

First, in step S31, the recognition unit 9 detects the center position Y, for example. is received from the control unit 8. This central position Y. teeth,
This is designated by the control unit 8 as the position where the recognition unit 9 should read from the multi-value data storage means 5. In the next step S32, the X address of the binary data storage means 7 is
4. Set as .

In step S33, as a result of checking on the binary data storage means 7, the continuous count value N, which counts the number of continuous white pixels, is set to O. In step S34, it is checked whether the data at the address at the coordinates (x, Yo) is O or 1. If it is 0, 1 is added to the continuous count value in step S35. Then, in the next step S36, it is determined whether this continuous count value N is a predetermined value No or not. The continuous count value N is the predetermined value N. Where is not equal to ? In step S37, 1 is added to the X address. That is, move the X address one place to the right. Then, in the next step S38, it is checked whether the X address exceeds X maX. If the X address does not exceed X8, the process returns to step S34 described above, and step 334
- Repeat the process of S37.

On the other hand, if the X address exceeds X■E, in step S39, information that the left end of the form 10 cannot be detected is sent to the control section 8, and the program is terminated.

If the continuous count value N is equal to N0 in step S36, then in step S303, the left end address as the left end position of the form is sent to the control unit 8 as x-No+1, and this program is ended.

On the other hand, in step S34, if the data of the coordinates (x, Yo) is 1, in step S301, the X address is moved right by 1.
Move one. Then, in the next step S302, it is determined whether the X address exceeds X8. The X address is X. If it does not exceed X, the process returns to step S33. X address is X m. ．． If it exceeds , it is determined that a left edge detection error has occurred in step S39, and the program is terminated.

Through the process described above, the left end address x-N of the obtained form
Based on o+1, find the written position of the character to be read.

FIG. 5 is a diagram showing information specified in the form format stored in the control unit 8. As shown in FIG.

The illustrated form format indicates that the character field 42 is located at a predetermined distance from the left edge 4l of the form. That is, between the left edge 41 of the form and the left edge 44 of the character field,
A distance 43 separates them. Further, a distance 46 is provided between the left end 41 of the form and the right end 45 of the character field. These distances 43 and 46 are stored in the control unit 8.

The control unit 8 receives the address of the left edge 41 of the form from the recognition circuit 9, calculates the left edge 44 of the form field and the right edge 45 of the form field in the binary data storage means 7, and transmits the calculation result to the recognition circuit 9. Thereafter, the recognition circuit 9 performs character reading processing for the character field 42.

(Problems to be Solved by the Invention) However, the optical character reading device having the above configuration has the following problems.

That is, as shown in FIG. 3, the control section 8 controls the photoelectric conversion section 1
When detecting the left edge 21 of a form by scanning from the left edge 25 to the right edge 26, this detection sometimes takes time. In other words, there is a problem in that it takes time to detect the left end of the form 10, which has a small form width.

FIG. 5 is a diagram illustrating the above-mentioned situation.

Form data 51 and 52 indicate form data stored in the binary data storage means 7. Since the right end of the form 10 is held by the conveying mechanism 4 and read, the data on the form 10 is stored in the multi-value data storage means 5 and the binary data storage means 7, with the data on the form 10 shifted to the right side. Therefore, when the width of the form 10 is small, the left edge of the form is far to the right. The left edge 53 of the form data 5l is to the left of the center of the form data 51. The left edge 54 of the form data 52 is on the right side of the center of the form data 5l. Therefore, form data 5
2, compared with the form data 51, the left end 5 of the form
It takes time to detect 4.

It goes without saying that a similar problem occurs in detecting the right end of the form when the left end of the form is held by the conveying mechanism and read.

The present invention has been made with attention to the above points, and an object of the present invention is to provide an optical character reading device that does not take much time to detect the edge of a form even when the width of the form is small. It is something.

(Means for Solving the Problems) The optical character reading device of the present invention is an optical character reading device that reads data on a form using photoelectric conversion means, and includes a detection means for detecting the position of the form, and a detection means for detecting the position of the form. The present invention is characterized by comprising a range limiting means for limiting the detection range of the edge of the form of the photoelectric conversion means according to the detection result, and detecting the edge of the form within the range limited by the range limiting means. It is something.

(Operation) In the above device, the photoelectric conversion means reads the form within the detection range limited by the range limiting means according to the detection result of the detection means for detecting the position of the form. This reduces the time required to detect the edges of a form.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of an optical character reading device of the present invention.

The illustrated device has a photoelectric conversion means 11 similar to the conventional one.
, the binarization means 6, the binary data storage means 7, the control section 8', the recognition section 9, etc. The photoelectric conversion means 11 includes a photoelectric conversion section 1, a light source 2, a condensing lens 3, and a transport mechanism 4.
and a multi-value data storage means 5. The details of each part are the same as those of the conventional device described above, so a redundant explanation will be omitted.

The illustrated device also includes detection means 71 and 72 and range limiting means 73.

The detection means 71 and 72 are light emitting parts 71a and 7, respectively.
2a, and light receiving sections 7lb and 72b. Light emitting part 7
1a and 72a are comprised of light emitting diodes and the like, and emit light to light receiving sections 7lb and 72b, respectively. The light receiving sections 7lb and 72b receive light beams emitted from the light emitting sections 71a and 72a, respectively, from a phototransistor or the like. Therefore, when the form 10 is located at the position of the detection means 71 or 72, the light beam is blocked by the form 10 and does not reach the light receiving section 7lb or 72b. This makes it possible to detect the range in which the form exists.

The range limiting means 73 is for limiting the scanning range of the photoelectric conversion means 1 in the main scanning direction. This range limiting means 73 will be explained in detail below.

FIG. 7 is a diagram showing the corresponding positions of the detection means 71 and 72 of FIG. 1 on the binary data storage means 7. Moreover, FIG. 8 shows the photoelectric conversion means 11 l 2 ? of FIG. 1. FIG. 3 is a diagram showing the contents of a table storing X addresses for specifying a limited range of scanning.

In the main scanning direction by the photoelectric conversion unit 1, that is, in the X direction, s
XIl% X21% Xl2% X31% X2
Each X address of 2 and x32 is set. These address values are stored in the table shown in FIG. Here, between each X address, X++<X2+<
There is a relationship of X12<X31<X22<X32.

As shown in FIG. 7, a detection means 7l is provided between addresses X21 and x1■. Also, address x
A detection means 72 is provided between 3 and x22. Therefore, when the presence of the form 10 is not detected by either of the detection means 71 and 72, the form 10 is
It is located on the right side of the position of the detection means 72. Therefore, the left end of the form 10 may be detected in the range between X31 and x32.

Further, as shown in FIG. 8, when the presence of the form 10 is not detected by the detection means 71 and the presence of the form 10 is detected by the detection means 72, the form 10 is located at a position lower than the position of the detection means 7l. It is located on the right side, and the left end of the form 10 is located on the left side of the position of the detection means 72. For this reason, form 1
The left end of 0 may be detected in the range between X2+ and X22.

Furthermore, both the detection means 71 and 72 detect the form 10.
When the presence of the document 10 is detected, the left end of the form 10 is on the left side of the position of the detection means 71.

Therefore, the left end of the form 10 may be detected in the range between the x-th point and Xl2.

Furthermore, when the presence of the form 10 is detected by the detection means 71 and the presence of the form 10 is not detected by the detection means 72, the left end of the form 10 is to the left of the position of the detection means 71. Therefore, the left end of the form 10 may be detected in the range between X++ and Xl2.

As described above, the form 1 detected by the detection means 71 and 72 is
Depending on the detection state of 0, the range in which the photoelectric conversion unit 1 detects the left end of the form 10 is limited. As a result, the reading of the form 10 by the photoelectric conversion unit 1 1 3 1 A ? time is reduced.

FIG. 9 is a flowchart showing the processing procedure for determining the left edge of a form by the apparatus of the present invention.

First, in step S90, xn, is determined as the X address to be used in step S92, and X as the X address to be used in steps S98 and S902, according to the detection results of the form 10 by the detection means 71 and 72. Determine 2. Here, x0 is x3,%X2 as shown in Figure 8.
■or Xl1, and XI12 is x3. , x2■ or XI2. In step S91, the recognition unit 9
For example, center position Y. is received from the control section 8'. The control unit 8' selects the center position Y as the position to be read into the multivalued data storage means 5. Specify. This central position Y. is designated by the control unit 8' as a position to be read from the multivalued data storage means 5. In the next step S92,
The X address of the binary data storage means 7 is set as xn.

In step S93, as a result of checking on the binary data storage means 7, a continuous count value N for counting the number of continuous white pixels is set to O. In step S94, it is checked whether the data at the address of the coordinate (x.Yo) is O or I. In the case of O, 1 is added to the continuous count value in step S95. Then, in the next step S96, it is determined whether this continuous count value N is a predetermined value No or not. The continuous count value N is the predetermined value N. If not equal, 1 is added to the X address in step S97. That is, move the X address one place to the right. Then, in the next step S98, the X address is X. Check whether it exceeds 2. X address is X. If it does not exceed 2, the process returns to step S94 described above, and steps S94 to S
97 is repeated.

On the other hand, if the X address exceeds Xn2, in step S99, information that the left end of the form 10 cannot be detected is sent to the control section 8', and the program is ended.

Further, in step S96, the continuous count value N is N.

If it is equal to, in step S903, the left end address as the left end position of the form is sent to the control unit 8'15 1 6 as x-No+1, and this program is terminated.

On the other hand, if the data of the coordinates (x, Yo) is 1 in step S94, the X address is moved one position to the right in step S901. Then, in the next step S902, it is determined whether the X address exceeds xn2. The X address is X. If it does not exceed 2, the process returns to step S93. The X address is X. If the number exceeds 2, a left edge detection error is determined in step S99, and the program is terminated.

Through the process described above, the left end address x-N of the obtained form
Based on o+1, find the written position of the character to be read. This is done according to the form format shown in FIG. 5, as described above.

The optical character reading device of the present invention is not limited to the above embodiments.

That is, in the embodiment described above, the detection means 71 and 7
Although two detection means (2) are provided, the number of detection means is not limited to this, and may be three or more. If the number of detection means is three or more, the detection range of the left end of the form 10 can be more finely limited. Further, the number of detection means may be only one. Furthermore, it goes without saying that the roles of the left end and right end may be switched to detect the right end position.

(Effects of the Invention) The optical character reading device of the present invention configured as described above is provided with a detection means for detecting the position and size of a form, and detects and outputs the left end of the form according to the detection result of the detection means. By limiting the number of times, it is possible to shorten the time to detect the edge of the form, and the time to read the form can be shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the optical character reading device of the present invention, FIG. 2 is a block diagram showing a conventional optical character reading device, and FIG. 3 is a block diagram showing an example of the optical character reading device of the present invention. FIG. 4 is a flowchart showing the conventional procedure for detecting the left edge of a form, FIG. Figure 7 is an explanatory diagram of the positional relationship corresponding to the binary data buffer of the detection means, and Figure 8 is a diagram that simply explains the difference in the storage state of form data. A diagram showing the contents of the stored table,
FIG. 9 is a flowchart showing a procedure for detecting the left edge of a form according to the present invention. DESCRIPTION OF SYMBOLS 1... Photoelectric conversion unit, 2... Light source, 3... Condensing lens, 4... Transport mechanism, 5... Multi-value data storage means,
6... Binarization means, 7... Binary data storage means, 8
．． 8'...Control unit, 9...Recognition unit, 71.72...
- Detection means, 73... range limiting means.

Claims (1)

[Scope of Claims] An optical character reading device that reads data on a form using photoelectric conversion means, comprising a detection means for detecting the position of the form, and a detection means for detecting the edge of the form by the photoelectric conversion means in accordance with a detection result of the detection means. What is claimed is: 1. An optical character reading device comprising: range limiting means for limiting a range; and detecting an edge of a form within the range limited by the range limiting means.