TWI398619B - Orthogonal correction method - Google Patents

Description

Orthogonal correction method

The present invention relates to an orthogonal correction method, and more particularly to an orthogonal correction method for geometrical proportional relationship of an operation image.

In the prior art, many orthogonal correction methods perform a calibration operation by an operator using a hardware tool such as a corner gauge. It scans a calibration sheet with a scanning system and obtains a captured image. After the operator visually measures the captured image, and determines whether the scanning system has an offset angle, the scanning system is corrected by a hardware tool such as a corner gauge. However, by using a hardware tool such as a visual inspection method and a corner gauge to perform calibration of the scanning system, the correction is often inaccurate due to human error.

Therefore, in the prior art, the calibration of the scanning system cannot be quickly completed because the correction is inaccurate, and it is often necessary to spend more time to repeat the correction. Therefore, how to improve the accuracy and speed of correction is a very important issue.

Under this premise, the inventor of this case deeply felt the need to develop a new orthogonal correction method to simultaneously improve the above problems.

In the prior art, the offset angle of the scanning system is determined by manual visual inspection, and the calibration of the scanning system is performed by a hardware tool such as an angle gauge. It is often because of the operator's omission that the correction is inaccurate and it takes more time to repeat the correction.

Accordingly, it is a primary object of the present invention to provide an orthogonal correction method for correcting a scanning detection system using a calibration sheet, wherein the calibration sheet and the scanning detection system are relatively moved in a set direction. Scanning detection system performs a line scan operation on the calibration slice along the line scan direction, and obtains a scan geometric image, and then compares the geometrical ratio of the scanned geometric image with a known geometric image to obtain a comparison. Correct the angle. Finally, at least one of the set direction and the line scan direction is adjusted according to the correction angle such that the set direction and the line scan direction are orthogonal to each other.

Therefore, the geometrical correlation between the scanned geometric image and the known geometric image can be accurately and quickly calculated by a simple geometric formula. Thereby, the above various problems can be effectively solved.

The invention solves the problems of the prior art, and the technical means adopted provides an orthogonal correction method for the first-line scanning image capturing device and a correction piece to move relative to each other in a set direction, so that the setting direction is The line scanning directions of the line scanning image capturing device are orthogonal to each other, the calibration sheet has a known geometric image, and the orthogonal correction method comprises the following steps:

(a) moving the line scan image capturing device and the correcting piece relative to each other in the set direction, and using the line scanning image capturing device to perform a line scan operation on the correcting piece along the line scanning direction, thereby obtaining the correcting piece One of the scanned geometric images;

(b) calculating a correction angle using the scan geometry image and at least two geometric scales of the known geometric image;

(c) adjusting at least one of the set direction and the line scanning direction according to the correction angle such that the set direction and the line scanning direction are orthogonal to each other.

Compared with the conventional orthogonal correction method, the offset angle of the scanning system is determined by manual visual inspection, and the calibration of the scanning system is performed by a hardware tool such as an angle gauge. Since the orthogonal correction method disclosed in the example of the present invention performs the geometric ratio comparison by scanning the geometric correlation between the geometric image and the known geometric image. Obviously, the orthogonal correction method disclosed in the example of the present invention can accurately and quickly calculate the correction angle without further complicated operation procedure by using a complicated operation procedure, thereby improving the orthogonal correction efficiency. . In order to effectively solve the above problems.

The specific embodiments of the present invention will be further described by the following examples and drawings.

The orthogonal correction method provided by the present invention can be widely applied to correct various scanning detection systems, and the related combined implementation manners are numerous, so it will not be further described herein, and only one of the preferred embodiments is specifically described. Description.

Please refer to the first figure, which is a side view of a system architecture of a preferred embodiment of the present invention. The present invention utilizes a calibration sheet 1 to correct a scanning detection system 2. The scanning detection system 2 can include a stage 21, a line scan image capturing device 22, a rotating platform 23, an electronic device 24, and a light source 25.

The correction sheet 1 is placed on the stage 21 and moved in a set direction D1. The correction sheet 1 may have a known geometric image f1 which may be the outer contour of the correction sheet 1 or a geometric image marked on the surface of the correction sheet 1. In the preferred embodiment, the geometric image f1 is known to be the outer contour of the correction sheet 1 and is a circular image. The geometric image f1 is known to be stored in the electronic device 24.

The line scan image capturing device 22 is disposed on the rotating platform 23 , and the line scanning image capturing device 22 is electrically connected to the electronic device 24 . Therefore, after the online scanning image capturing device 22 captures a scanning geometric image, the scanned geometric image captured by the online scanning image capturing device 22 can be transmitted to the electronic device 24.

The electronic device 24 includes a memory unit 241, a display unit 242, an operation unit 243, and a control unit 244. The memory unit 241 can be used to store the known geometric image f1, and the memory unit 241 can be electrically connected to the arithmetic unit 243. The display unit 242 can be used to display a scanned geometric image, and the display unit 242 can be electrically connected to the arithmetic unit 243. The arithmetic unit 243 can be used to calculate a comparison program, and the arithmetic unit 243 can be electrically connected to the line scan image capturing device 22. The control unit 244 can be used to perform a calibration process, and the control unit 244 can be electrically connected to the arithmetic unit 243 and the rotating platform 23. The electronic device can be a computer.

Please refer to the second figure, which is a schematic top view of the system architecture of the preferred embodiment of the present invention, and please refer to the first figure. When the scanning detection system 2 is corrected by the correction sheet 1, the correction sheet 1 can be placed on the stage 21 first, and a relative movement between the correction sheet 1 and the line scanning image capturing unit 22 is generated.

In particular, it should be emphasized that the relative movement referred to herein refers to the relative movement relationship between the calibration sheet 1 and the line scan image capturing device 22. In practice, as long as the calibration sheet 1 and the loading table 21 are The relative movement of the line scan image capture device 22 is effected by one of the line scan image capture devices 22. Preferably, in the embodiment, the correcting sheet 1 can be moved along the set direction D1 to generate the relative movement, and the light source 25 can illuminate a detecting beam (not shown) on the correcting sheet 1; After the detection beam penetrates the stage 21, the line scan image capturing device 22 can obtain the scanned geometric image of the correction sheet 1 when scanning the correction sheet 1 along the line scanning direction D2. For those skilled in the art, the scanning operation described above is a transmissive line scan operation.

As shown in the second figure, when the above-described transmissive line scanning operation is performed, there is an angle ω ₁ between the set direction D1 and the line scanning direction D2. Among them, the transmissive line scanning operation is a conventional technique, so it will not be described here.

After the line scan image capturing device 22 completes the transmissive line scan operation and obtains the scan geometry image, the line scan image capture device 22 transmits the scan geometry image to the electronic device 24, so that the electronic device 24 is based on the scan geometry. The program is compared to the known geometric image f1.

For example, please refer to the third figure, which is a comparison diagram of a known geometric image and a scanned geometric image of a calibration patch when the line scanning direction and the setting direction are orthogonal to each other in the preferred embodiment of the present invention. After the transmissive line scan operation described above is completed, the scanned geometric image can be transmitted to the electronic device 24 and displayed on the display unit 242.

At this time, the arithmetic unit 243 of the electronic device 24 compares the scanned geometric image with the known geometric image f1. As shown in the third figure, if the scanned geometric image displayed on the display unit 242 is a circular image f2, it means that the angle ω ₁ between the set direction D1 and the line scanning direction D2 is 90 degrees; The display unit 242 can display related information that the calibration procedure has been completed.

Please refer to the fourth and fifth figures. The fourth figure is a schematic top view of the system architecture in which the setting direction and the line scanning direction are not orthogonal to each other in the preferred embodiment of the present invention; and the fifth figure shows the preferred embodiment of the invention. A comparison chart between the calibration slice and the scanned geometric image in which the line scanning direction and the setting direction are not orthogonal to each other; and, please refer to the first figure together. After the transmissive line scan operation described above is completed, the scanned geometric image can be transmitted to the electronic device 24 and displayed on the display unit 242.

At this time, the arithmetic unit 243 of the electronic device 24 compares the scanned geometric image with the known geometric image f1, as shown in the fifth figure, if the scanned geometric image displayed on the display unit 242 is corrected because of the angle θ The distortion into an elliptical image f3 indicates that the scanned geometric image is different from the known geometric image f1. In this case, the line scanning direction D2 of the line scan image capturing device 22 and the setting direction D1 of the correction sheet 1 are not orthogonal to each other, that is, the angle ω ₂ between the setting direction D1 and the line scanning direction D2 is not 90 degrees. At this time, the display unit 242 can display a related message that a subsequent correction procedure must be performed.

As shown in the fourth figure, the set direction D1 and the line scanning direction D2 have an angle ω ₂ and a correction angle θ, and the angle ω ₂ and the correction angle θ are mutually complementary angles. The correction work to be performed next is to calculate the correction angle θ, thereby adjusting the rotating platform 23 so that the angle ω ₂ is 90 degrees and the correction angle θ is zeroed.

Next, a method of calculating the correction angle θ will be further enumerated. In the fifth diagram, when the correction angle θ is sandwiched between the line scanning direction D2 of the line scan image capturing device 22 and the setting direction D1 of the correction sheet 1. A diamond image may be externally connected to the known geometric image f1 of the correction sheet 1 according to the correction angle θ and the scanning distance L of one of the line scan image capturing devices 22. According to the apex angle theorem, the collocation theorem and the geometrical characteristics of the diamond, the angle ω ₂ and the angle ω ₂ /2 can be indicated.

In a preferred embodiment of the present invention, since both the geometric image f1 and the elliptical image f3 are known to be two-dimensional planes, at least three reference points can be selected for the known geometric image f1, and such The reference point is connected to at least three reference line segments; at the same time, at least three corresponding points corresponding to the reference points are found in the elliptical image f3, and the corresponding points are connected to at least three corresponding to the at least three Referencing the corresponding line segment of the line segment, and calculating the correction angle by using at least two geometric ratios of the reference line segments and the corresponding line segments.

However, in order to explain how to calculate the correction angle θ, a first reference point A1, a second reference point A2, a third reference point A3, and a fourth reference point may be selected in the calibration sheet 1 in the fifth figure. A4 and a fifth reference point A5.

And connecting the first reference point A1 and the second reference point A2 to form a first reference line segment Y, connecting the first reference point A1 and the third reference point A3 to form a second reference line segment R1, connecting the first reference point A1 with The fourth reference point A4 is formed to form a third reference line segment X, and the first reference point A1 and the fifth reference point A5 are connected to form a fourth reference line segment R2.

In addition, since the correction angle θ is sandwiched between the line scanning direction D2 of the line scan image capturing device and the setting direction D1 of the correction sheet 1, the scanning geometric image is distorted from the circular image f2 into an elliptical image f3. . Therefore, a square image can be externally connected to the elliptical image f3 according to the scanning distance L of the line scan image capturing device 22.

And selecting a first corresponding point B1, a second corresponding point B2, a third corresponding point B3, a fourth corresponding point B4 and a fifth corresponding point B5 in the elliptical image f3. Wherein, the first corresponding point B1, the second pair The point B2, the third corresponding point B3, the fourth corresponding point B4 and the fifth corresponding point B5 correspond to the first reference point A1, the second reference point A2, the third reference point A3, and the fourth reference point A4, respectively. Five reference points A5.

Connecting the first corresponding point B1 and the second corresponding point B2 to form a first corresponding line segment S1, connecting the first corresponding point B1 and the third corresponding point B3 to form a second corresponding line segment P, connecting the first corresponding point B1 and the first Four corresponding points B4 are formed to form a third corresponding line segment S2, and the first corresponding point B1 and the fifth corresponding point B5 are connected to form a fourth corresponding line segment Q.

The first corresponding line segment S1, the second corresponding line segment P, the third corresponding line segment S2 and the fourth corresponding line segment Q are respectively corresponding to the first reference line segment Y, the second reference line segment R1, the third reference line segment X and the fourth Reference line segment R2.

Then, according to the proportional relationship between the known geometric image f1 and the elliptical image f3, the following two identity equations are generated: Y : R 1 = S 1: P K (1)

X : R 2= S 2: Q K (2)

The first reference line segment Y may be one-half of the long diagonal of the diamond pattern. The second reference line segment R1 may be the radius of the known geometric image f1 of the correction sheet 1. The third reference line segment X can be one-half of the short diagonal of the diamond pattern. The fourth reference line segment R2 may be the radius of the known geometric image f1 which may be the correction sheet 1. Therefore, the fourth reference line segment R2 is equal to the second reference line segment R1.

The first corresponding line segment S1 may be one-half of a square graphic diagonal. The second corresponding line segment P may be the minor axis radius of the elliptical image f3. The third corresponding line segment S2 may be one-half of the diagonal of the square pattern, and therefore, the third corresponding line segment S2 is equal to the first corresponding line segment S1. The fourth corresponding line segment Q can be the major axis radius of the elliptical image f3.

In addition, as can be seen from the fifth figure, the correction angle θ is sandwiched between the line scanning direction D2 of the line scan image capturing device and the setting direction D1 of the calibration sheet 1, and the long diagonal line of the diamond pattern is divided into two halves. ω ₂ /2. Therefore, according to the trigonometric function theorem, the following two equations can be derived:

Assuming that the scanning distance L of the line scan image capturing device has a length a, the sides of the diamond pattern and the square pattern are both a, so the following equation can be derived according to the Bisch's theorem:

By introducing equations (3), (4), and (5) into equations (1), (2), and R1 = R2, the following equations can be derived:

The following equations are derived from equations (6) and (7):

According to the residual angle theorem, the following equation can be derived:

θ=90°-ω ₂ ...(9)

By bringing equation (8) into equation (9), the following equation can be obtained:

Therefore, when the correction angle θ is sandwiched between the line scanning direction D2 of the line scan image capturing device 22 and the setting direction D1 of the correction sheet 1, the scanning geometric image system is distorted into an elliptical image f3. At this time, the electronic device 24 calculates the correction angle θ by calculating the lengths of the major axis radius P and the minor axis radius Q of the elliptical image f3 and respectively bringing them into the equation (10).

When the electronic device 24 calculates the correction angle θ, the correction operation is performed in accordance with the correction angle θ. The calibration operation may be such that the control unit 244 in the electronic device 24 transmits a correction signal U to the rotating platform 23 according to the correction angle θ. After receiving the correction signal U, the rotating platform 23 adjusts the rotating platform 23 according to the correction signal U to make the angle ω ₂ 90 degrees and zero the correction angle θ. Thereby, the line scanning direction D2 and the setting direction D1 are orthogonal to each other. In another embodiment, after the electronic device 24 calculates the correction angle θ, the setting direction D1 of the correction sheet 1 can be adjusted according to the correction angle θ, so that the line scanning direction D2 and the setting direction D1 are orthogonal to each other.

Referring to the sixth figure, in order to further promote the technology disclosed in the present invention, the technology disclosed in the preferred embodiment of the present invention will be further condensed into a simple flowchart so as to be more easily remembered by those having ordinary knowledge in the technical field. . Please refer to the first, fourth and fifth figures for the following component numbers.

The line scan image capturing device 22 and the correction sheet 1 are relatively moved in the set direction D1 (step S100).

The line scan image capturing device 22 is caused to perform a line scan operation on the correction sheet 1 in the line scanning direction D2 to acquire a scanned geometric image and transmit it to the electronic device (step S110).

Determining whether the scanned geometric image is identical to the known geometric image f1 (step S120)

When the scanned geometric image is different from the known geometric image f1, at least three reference points are selected in the known geometric image f1, and the reference points are connected into at least three reference line segments (step S130).

In the scanned geometric image, at least three corresponding points corresponding to the reference points are found, and the corresponding points are connected into at least three corresponding line segments respectively corresponding to the at least three reference line segments (step S140).

The correction angle θ is calculated using the condition that the reference line segments correspond to at least two geometric ratios of the corresponding line segments (step S150).

At least one of the setting direction D1 and the line scanning direction D2 is adjusted according to the correction angle θ, and the setting direction D1 and the line scanning direction D2 are orthogonal to each other (step S160).

Compared with the conventional orthogonal correction method, the offset angle of the scanning system is determined by manual visual inspection, and the calibration of the scanning system is performed by a hardware tool such as an angle gauge. Since the orthogonal correction method disclosed in the example of the present invention performs the geometric ratio comparison by scanning the geometric correlation between the geometric image and the known geometric image. Obviously, the orthogonal correction method disclosed in the example of the present invention can accurately and quickly calculate the correction angle without further complicated operation procedure by using a complicated operation procedure, thereby improving the orthogonal correction efficiency. . In order to effectively solve the above problems.

It can be seen from the above embodiments of the present invention that the present invention has industrial utilization value. The above embodiments are merely illustrative of the preferred embodiments of the present invention, and those skilled in the art will be able to make various other modifications and changes in the embodiments described herein. However, various modifications and changes made in accordance with the embodiments of the present invention are still within the scope of the invention and the scope of the invention.

1. . . Correction film

2. . . Scan detection system

twenty one. . . Loading platform

twenty two. . . Line scan image capture device

twenty three. . . Rotating platform

twenty four. . . Electronic device

241. . . Memory unit

242. . . Display unit

243. . . Arithmetic unit

244. . . control unit

25. . . light source

D1. . . Set direction

D2. . . Line scan direction

F1. . . Known geometric image

F2. . . Circular image

F3. . . Oval image

ω ₁ , ω ₂ . . . Angle

θ. . . Correction angle

A1. . . First reference point

A2. . . Second reference point

A3. . . Third reference point

A4. . . Fourth reference point

A5. . . Fifth reference point

B1. . . First corresponding point

B2. . . Second corresponding point

B3. . . Third corresponding point

B4. . . Fourth corresponding point

B5. . . Fifth corresponding point

Y. . . First reference line segment

R1. . . Second reference line segment

X. . . Third reference line segment

R2. . . Fourth reference line segment

S1. . . First corresponding line segment

P. . . Second corresponding line segment

S2. . . Third corresponding line segment

Q. . . Fourth corresponding line segment

U. . . Correction signal

The first figure is a side view of a system architecture of a preferred embodiment of the present invention;

2 is a top plan view of a system architecture of a preferred embodiment of the present invention;

The third figure shows a comparison diagram of the known geometric image and the scanned geometric image of the calibration sheet when the line scanning direction and the setting direction are orthogonal to each other in the preferred embodiment of the present invention;

The fourth drawing is a schematic plan view of a system architecture in which the setting direction and the line scanning direction are not orthogonal to each other in the preferred embodiment of the present invention;

Figure 5 is a view showing a comparison of a calibration slice and a scanning geometric image in which the line scanning direction and the setting direction are not orthogonal to each other in the preferred embodiment of the invention;

Figure 6 is a flow chart of a preferred embodiment of the present invention.

1. . . Correction film

2. . . Scan detection system

twenty one. . . Loading platform

twenty two. . . Line scan image capture device

twenty three. . . Rotating platform

twenty four. . . Electronic device

241. . . Memory unit

242. . . Display unit

243. . . Arithmetic unit

244. . . control unit

25. . . light source

D1. . . Set direction

F1. . . Known geometric image

F2. . . Circular image

F3. . . Oval image

U. . . Correction signal

Claims (7)

The method of orthogonal correction is used to make the set direction and the line scanning direction of the line scan image capturing device orthogonal to each other when the first line scanning image capturing device and the correcting piece move relative to each other in a set direction. The slice has a known geometric image, and the orthogonal correction method comprises: (a) moving the line scan image capturing device and the correcting piece relative to the set direction, and scanning the image capturing device along the line The line scanning direction performs a one-line scanning operation on the calibration sheet to obtain a scanning geometric image of the calibration sheet; (b) calculating a condition corresponding to at least two geometric proportions of the scanning geometric image and the known geometric image And a correction angle; and (c) adjusting at least one of the set direction and the line scanning direction according to the correction angle such that the set direction and the line scanning direction are orthogonal to each other. The orthogonal correction method of claim 1, wherein the known geometric image is an outer contour of the calibration sheet. The orthogonal correction method of claim 1, wherein the known geometric image is marked on a surface of the calibration sheet. The orthogonal correction method of claim 1, wherein the known geometric image is a circular image. The orthogonal correction method according to claim 4, wherein, in the step (b), when the set direction and the line scanning direction are not orthogonal to each other, the scanned geometric image is an elliptical image. image. The orthogonal correction method according to claim 1, wherein the step (b) further comprises a step (b1) of selecting at least three reference points in the known geometric image, and The reference points are connected into at least three reference line segments; at the same time, in the scanned geometric image, at least three corresponding points corresponding to the reference points are found, and the corresponding points are connected into at least three corresponding to the at least three references respectively. The corresponding line segment of the line segment. The orthogonal correction method according to claim 6, wherein the step (b) calculates the correction angle by using at least two geometric ratios of the reference line segments and the corresponding line segments.