JPH0615150U - Optical character reader - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if the inclination of the form changes during transportation, the character does not deviate from the character cutout position to prevent misreading or nonreading. [Arrangement] An edge detecting unit 11 for detecting the left side (or right side) of a form P is provided at regular intervals. A control unit 13 that calculates the amount of inclination of the form P at the position detected by the side detection unit 11 and corrects the character cutout position based on the calculated value is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical character reader (OCR) that reads characters on a form by an optical sensor.

[0002]

[Prior art]

 FIG. 6 is a block diagram showing a configuration example of a conventional optical character reading device. In the figure, the optical character reader controls a mechanical unit 2 that drives a roller 1 to convey a form P, an optical sensor 4 that reads an image 3 on the form P, and a mechanical unit 2 and an optical sensor 4. It is composed of a control unit 5. A memory 6 for storing the read image data is provided in the control unit.

FIG. 7 is a flowchart showing the operation of a conventional optical character reading device, and the operation will be described according to this flow chart. First, the form P is sucked and conveyed into the apparatus by the mechanism unit 2 (step 1). When the form P is conveyed to the reading position, it is read by the optical sensor 4 (step 2). The read image data is stored in the memory 6 in the control unit 5. The control unit 5 detects the edge (A) of the leading edge of the form based on this image data (step 3), and calculates the inclination (skew) of the form P with respect to the optical sensor line (shown in FIG. 8) (step 4). ). In this way, the inclination angle θ of the form P is obtained, the character cutting position is corrected by using this inclination angle θ as a correction angle, and character recognition is performed (step 5). FIG. 8 is an explanatory diagram showing the inclination of the form P.

[0004]

[Problems to be solved by the device]

 However, the above conventional device has the following problems. That is, especially when the length of the form in the conveyance direction is long, the form may meander during the conveyance. In such a case, the inclination of the reading position on the form with respect to the optical sensor line changes with the conveyance. As a result, there was a problem that the position of the character on the form and the position where the character was cut out were misaligned, resulting in erroneous reading or non-reading of the character (unreadable character).

The present invention has been made in view of the above problems, and an object of the present invention is to correct a character cutout position in response to a change in the inclination of a form during conveyance even if the inclination of the form changes. It is an object of the present invention to provide an excellent optical character reading device that prevents misreading or non-reading of characters by preventing the characters from shifting from the cutout position and improves the recognition rate.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention reads characters on a conveyed form with an optical sensor, calculates the amount of inclination of the form, and corrects the character cutting position based on the calculated amount of inclination to correct the character. An optical character reading device for recognition, which is provided with an inclination amount calculating means for calculating the inclination amount of a form at regular intervals, and corrects the character cutout position based on the inclination amount calculated by the inclination amount calculating means. Is.

[0007]

[Action]

 According to the present invention having the above-mentioned configuration, the tilt amount calculating means calculates the tilt amount of the conveyed form at regular intervals. Therefore, even when the form is meandered and conveyed, the tilt amount at the reading position can be more accurately obtained. Then, the character cutout position is corrected based on the calculated inclination amount.

[0008]

【Example】

 Embodiments according to the present invention will be described below with reference to the drawings. Note that elements common to the drawings are given the same reference numerals. 1 is a block diagram showing an optical character reader according to a first embodiment of the present invention. In FIG. 1, the optical character reading apparatus of the present embodiment is provided with a mechanism section 2 that conveys a driving form P through a roller 1 and an optical sensor 4 that reads an image 3 on the form P, as in the conventional example. ing.

A side detector 11 is provided so as to be connected to the optical sensor 4. The side detection unit 11 has a memory 12 that stores image data sent from the optical sensor 4, and detects the left side (or right side) of the form P. The control unit 13 controls the mechanism unit 2, the optical sensor 4, and the side detection unit 11, and includes a memory 14 that stores image data. The control unit 13 calculates the amount of inclination of the form P, cuts out characters, and recognizes characters.

Next, the operation of this embodiment will be described mainly with reference to the flowchart shown in FIG. First, the control unit 13 drives the mechanism unit 2 to rotate the roller 1 and suck the form P into the apparatus (step 11). When the form P is conveyed to the reading position, the image 3 on the form P is read by the optical sensor 4 (step 12).

The read image data is stored in the memory 12 of the side detection unit 11 and the memory 14 of the control unit 13. From this image data, the control unit 13 determines the edge position on the left side of the leading edge of the form (A shown in FIG. 3).₀Position) is detected (step 13). FIG. 3 is an explanatory diagram for explaining the reading operation of this embodiment. Next this position A₀The skew (skew) of the form P in (1) is calculated (step 14). This inclination is the inclination θ of the leading edge of the form P with respect to the optical sensor line in FIG. ₀ The calculation formula is as follows.

[Equation 1] Here, the coordinates of the left side position A ₀ of the leading edge of the form P are (x _A0 , y _A0 ) and the coordinates of the right side position B ₀ of the leading edge of the form P are (x _B0 , y _B0 ).

The control unit 13 sets the calculated inclination amount θ ₀ as a correction angle, and corrects the character cut-out position from the position Q shown by the broken line in FIG. 3 to the position Q ′ shown by the solid line based on this correction angle θ ₀ . . Then, character recognition is performed at the corrected cut-out position Q '(step 15).

At the time point when a predetermined amount L is conveyed from the leading edge, the left side of the form P is detected by the side detecting unit 11 (step 16). Then, the inclination θ ₁ of the form P at this position (A ₁ shown in FIG. 3) is obtained (step 14). This inclination θ ₁ is obtained by the following equation, where the coordinates of the position A ₁ are (x _A1 , y _A1 ). That is,

[Equation 2] Then, using this inclination θ ₁ as a correction angle, the character cutout position is corrected in the same manner as described above, and character recognition is performed.

In this way, the inclination of the form P is calculated every time the fixed amount L is conveyed, and the character cutout position is corrected based on this, and recognition is performed. The inclination θ _n at the left side position A _n (x _An , y _An ) conveyed n × L from the leading edge of the form P is calculated by the following equation. That is,

[Equation 3]

Next, a second embodiment of the present invention will be described. In the second embodiment, the inclination θ of the form P is calculated, and it is determined whether the difference between the inclination θ and the correction angle at that time is larger than a certain angle. If the difference is large, the inclination θ at the reading position is cut out as a character. This is the correction angle of the position. FIG. 4 is an explanatory diagram for explaining the operation of the second embodiment.

[0016] In FIG 4, when the slope at the form P tip and theta _0, the correction angle from the tip to the A ₁ is a theta _0. If the inclination at the position A ₁ is θ ₁ , it is determined whether the difference (θ ₁ −θ ₀ ) between the angles θ ₁ and θ ₀ is larger than a constant value S (for example, 0.03 ° to 0.05 °). When θ ₁ −θ ₀ <S, the correction value from A ₁ to A ₂ is θ ₀ , and when θ ₁ −θ ₀ > S, the correction value from A ₁ to A ₂ is θ ₁ . To do. By doing this, in the second embodiment, when the inclination of the form P is small, the character cut-out position is not corrected, so that an improvement in processing speed can be expected.

Next, a third embodiment of the present invention will be described. In the third embodiment, at a certain tilt calculation position, if the difference between the character cutout position correction angle up to that point and the correction angle at that calculation position exceeds a certain value (T ₁ ), the next tilt calculation position is set smaller. When the value is smaller than the constant value (T ₂ ) (T ₂ <T ₁ ), the next tilt calculation position is set to be large. FIG. 5 is an explanatory diagram for explaining the operation of the third embodiment.

In FIG. 5, A₀The slope at₀, A₀To L₀Position A transported only ₁ The slope at₁Then, θ₀And θ₁Difference (θ₁−θ₀) Is a constant value T₁If it is larger than (for example, 0.2 ° to 0.3 °), A₁To the next tilt calculation position A ₂ Distance to L₁To L₀Make it smaller (L₁<L₀). Also θ₀And θ₁Difference (θ ₁ −θ₀) Is a constant value T₂If it is smaller than (for example, 0.03 ° to 0.05 °), A₁To A₂Distance to₁To L₀Make it larger (L₁> L₀). See also T₁ > Θ₁−θ₀> T₂If, L₁= L₀And

As described above, in the third embodiment, when the meandering amount (θ _n −θ _n-1 ) of the form P is small, the next inclination calculation position is set to a large value, so that the processing speed is increased and the meandering amount is increased. If is large, the next tilt calculation position is made smaller, and the character cutout position becomes even more difficult to shift.

[0020]

[Effect of device]

 As described in detail above, according to the present invention, even if the form is meandered during reading, the inclination is calculated at a constant interval and the character cutout position is corrected, so that the characters on the form can be corrected from the character cutout position. It will not stick out, and the chances of misreading and non-reading will be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment according to the present invention.

FIG. 2 is a flowchart showing the operation of the first embodiment.

FIG. 3 is an explanatory diagram showing the operation of the first embodiment.

FIG. 4 is an explanatory diagram showing the operation of the second embodiment.

FIG. 5 is an explanatory diagram showing the operation of the third embodiment.

FIG. 6 is a block diagram showing a conventional optical character reader.

FIG. 7 is a flowchart showing the operation of a conventional example.

FIG. 8 is an explanatory diagram showing the inclination of a form.

[Explanation of symbols]

 2 Mechanism part 4 Optical sensor 11 Edge detection part 13 Control part P form

Claims (3)

[Scope of utility model registration request] 1. An optical character reading device for reading characters on a conveyed form by an optical sensor, calculating the amount of inclination of the form, and correcting the character cut-out position based on the calculated amount of inclination for character recognition. 2. An optical character reading device, comprising: a tilt amount calculating means for calculating the tilt amount of a form at regular intervals, and correcting the character cutout position based on the tilt amount calculated by the tilt amount calculating means. 2. An optical character reading device for reading characters on a conveyed form by an optical sensor, calculating the amount of inclination of the form, correcting the character cut-out position based on the calculated amount of inclination, and performing character recognition. In (1), a tilt amount calculation means for calculating the tilt amount of the form is provided, and when the tilt amount calculated by the tilt amount calculation means exceeds a predetermined amount, the character cutout position is corrected based on the tilt amount. An optical character reader characterized by. 3. An optical character reading device for reading characters on a conveyed form by an optical sensor, calculating the amount of inclination of the form, correcting the character cut-out position based on the calculated amount of inclination, and performing character recognition. 2. An optical character reader according to claim 1, further comprising: an inclination amount calculating means for calculating the inclination amount of the form with a gap, and changing the gap according to a change amount of the inclination amount.