Positioning compensation method for display panel camera

Abstract

The invention provides a positioning compensation method of a display panel photographing machine. The method comprises the following steps: measuring straightness and linearity of an X axis and a Y axis, and perpendicularity between the X axis and the Y axis; wherein the X axis is the extension direction of the display panel clamping mechanism, the Y axis is the extension direction of the photographing machine, and the photographing machine is installed on the two sides of the clamping mechanism in a crossing mode and used for photographing the display panel; and performing linear combination on the straightness and linearity of the X axis and the Y axis and the perpendicularity between the X axis and the Y axis, and then compensating and correcting the X axis and the Y axis so as to perform positioning compensation of the photographing machine. The microscope is installed on the photographing machine, the photographing machine can move back and forth on the X axis along the sliding rail, and the microscope can move back and forth in the Y axis direction along the sliding rail. A deviation test and corresponding compensation method is adopted to solve the problem that positioning is not accurate enough. Through testing and verification, the method can greatly improve the shaft positioning precision, enables the system error to meet the design requirement, and is good in stability.

Description

Technical Field

[0001] The present invention relates to the technical field of display panels, and in particular to a positioning compensation method for a display panel camera. Background Art

[0002] With the development of the display panel industry, the manufacturing process of integrated circuits has been continuously improved, and the precision requirements are getting higher and higher. In order to clarify the process problems, after detecting the defects, particles, feature points and other areas of interest, use a camera to reach the designated location to take clearer photos. Due to comprehensive factors such as hardware manufacturing errors, assembly errors, component thermal reactions, and control compensation errors, it is impossible to meet the higher precision movement requirements, or cause the system error to exceed the standard. Even worse, when the camera reaches the designated position, the area of ​​interest is offset from the center of the microscope field of view, or the area of ​​interest cannot be found when switching to a high-magnification lens; in the face of this situation, in addition to improving the hardware's own process and assembly accuracy, there will still be certain system errors due to the superposition of multiple factors.

[0003] By controlling the camera's microscope to move to a specified position and zooming in on the area of ​​interest, more detailed images can be obtained. However, due to interference factors such as hardware, software, and environment, a certain deviation occurs under comprehensive superposition, leading to the following problems:

[0004] (1) There is a certain deviation between the actual movement position of the microscope and the theoretical one;

[0005] (2) The defect is not in the center of the image when it is photographed (or the deviation is large);

[0006] (3) When switching to a higher magnification, the area of ​​interest is not in the field of view;

[0007] (4) The system error does not meet the standard.

[0008] The above problems can be summarized as inaccurate positioning, which brings troubles in use and cannot achieve higher-precision motion effects.

[0009] The existing technologies generally include: (1) using CCD to collect regularly arranged Marks, perform template matching, record the deviations of X and Y, and use this data to compensate the axis; this method is relatively general, cannot analyze the source of the error, and has a relatively low resolution; (2) installing a laser interferometer structure to adjust the movement state of the axis through real-time feedback of the moving distance; this method has high accuracy and strong reliability, but high cost, complex structure, and high requirements for the use environment. Considering applicability, it is not the best choice.

[0010] The existing compensation methods have the following disadvantages when facing practical engineering problems:

[0011] 1. There are great differences in structure, environment, cost, application scenarios, etc. in different fields, and it is impossible to directly learn from them;

[0012] 2. Positioning accuracy is a comprehensive issue. Using a general test method cannot troubleshoot system problems.

[0013] 3. The source of positioning deviation is unclear, and it is impossible to identify the link where the problem exists, and it is impossible to give a clear solution;

[0014] 4. Use the matching MARK mark method to determine the offset. The arrangement and number of MARK marks on the display panel are relatively limited, the resolution is not high enough, and the calculation method is relatively complicated. Summary of the invention

[0015] The purpose of the present invention is to solve the problem of inaccurate positioning by adopting a method of deviation testing and corresponding compensation.

[0016] The key points of the present invention are: (1) using a method of measuring the position offset of a straight line edge to calculate the deviation;

[0017] (2) Comprehensive problems are decomposed into linearity, straightness, and perpendicularity; (3) Independent tests can help engineers troubleshoot system problems; (4) The characteristics of linear systems are utilized to superimpose and integrate system errors to achieve precise positioning compensation.

[0018] Specifically, the present invention provides a positioning compensation method for a display panel camera, comprising:

[0019] Measure the straightness and linearity of the X-axis and Y-axis, and the perpendicularity between the X-axis and the Y-axis; wherein the X-axis is the extension direction of the display panel clamping mechanism, and the Y-axis is the extension direction of the camera, which is installed across both sides of the clamping mechanism and is used to take pictures of the display panel;

[0020] The straightness and linearity of the X-axis and Y-axis, as well as the perpendicularity between the X-axis and the Y-axis are linearly combined, and then the X-axis and the Y-axis are compensated and corrected to perform positioning compensation for the camera.

[0021] Furthermore, the microscope is mounted on the camera, the camera can move back and forth along the slide rail on the X-axis, and the microscope can move back and forth along the slide rail in the Y-axis direction.

[0022] Furthermore, in the measurement, Pattern glass is used as a measuring tool, and the interior of the Pattern glass has horizontal and vertical straight line standard processes and has a regular panel distribution.

[0023] The advantages of the present invention are: the present invention adopts a method of deviation testing and corresponding compensation to solve the problem of inaccurate positioning. Through testing and verification, the method can greatly improve the shaft positioning accuracy, make the system error meet the design requirements, and have good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0025] Figure 1 A schematic diagram of the hardware structure involved in the positioning compensation method of a display panel camera according to an embodiment of the present invention is shown.

[0026] Figure 2 A schematic diagram of a motion platform and a panel model according to an embodiment of the present invention is shown.

[0027] Figure 3 A schematic diagram of the linearity measurement process of the X-axis and the Y-axis according to an embodiment of the present invention is shown.

[0028] Figure 4 A schematic diagram of the linearity measurement process of the X-axis and the Y-axis according to an embodiment of the present invention is shown.

[0029] Figure 5 A schematic diagram of a vertical measurement process between an X-axis and a Y-axis according to an embodiment of the present invention is shown.

[0030] Figure 6 A schematic diagram of a method for calculating a compensation value in the X direction according to an embodiment of the present invention is shown.

[0031] Figure 7 A schematic diagram of a method for calculating a compensation value in the Y direction according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0032] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0033] Figure 1 FIG. 2 shows a schematic diagram of the hardware structure involved in the positioning compensation method of the display panel camera according to an embodiment of the present invention. Figure 1As shown, it includes a microscope, a clamping mechanism, an X-axis, a Y-axis, a glass panel, and a camera. The X-axis is the extension direction of the display panel clamping mechanism, and the Y-axis is the extension direction of the camera. The camera spans across both sides of the clamping mechanism and is used to take pictures of the display panel; the microscope is installed on the camera. The camera can move back and forth on the X-axis along the slide rail, and the microscope can move back and forth on the Y-axis along the slide rail.

[0034] The straightness and linearity of the X-axis and Y-axis, as well as the perpendicularity between the X-axis and the Y-axis are linearly combined, and then the X-axis and the Y-axis are compensated and corrected to perform positioning compensation for the camera.

[0035] The two-dimensional position of the camera machine is determined by the X and Y directions. The control and movement of each axis are independent. The accuracy of the positioning is directly related to these two axes. In order to improve the accuracy of positioning and better troubleshoot problems, this method proposes an offline deviation measurement and corresponding compensation method for the axis to solve the problem. Each axis is independent, so it needs independent compensation. This method measures the straightness, linearity, and verticality of each axis, linearly combines these three sets of parameters, and then compensates and corrects each axis to achieve precise positioning.

[0036] In the present invention, the parameter test of the axis needs to use the pattern process glass as a measuring tool. The pattern has horizontal and vertical straight line standard processes inside, with regular panel distribution, running through the entire glass, and the motion platform and panel model are as follows: Figure 2 shown.

[0037] According to the two-dimensional matrix point map, this method moves the microscope to the specified point, uses the microscope to collect images, calculates the X\Y direction edge position of the marked straight line, calculates and records the position X0\Y0 at the starting point, and performs the same operation at other points, and collects images in turn to calculate and record the straight line edge position X n \Y n , the deviation between other points and the starting point:

[0038] X direction: E = X n -X0

[0039] The Y direction is: E = Y n -Y0

[0040] Based on the above deviation calculation method, the following axis offset performance measurement is completed, and the compensation accuracy can be controlled by changing the density of the two-dimensional matrix.

[0041] The clamping mechanism is used to adjust the posture of the panel glass so that the Pattern glass is basically parallel to the X-axis. The following offline measurements and online calculations and compensations are performed. The specific methods and steps are as follows:

[0042] 1. X and Y axis linearity measurement

[0043] 1) X-axis straightness X_DY measurement

[0044] Find the straight line process in the X direction of the Pattern glass near the head position of X=0, move the X axis (dot matrix) in the positive direction at equal intervals, and the Y direction position Y0 of the straight line edge in the microscope field of view at the starting X0 position and the current X n Position Y direction position of the straight edge in the microscope n The difference is X_DY. Record each X position and the corresponding DY until the end, throughout the X direction of the glass.

[0045] The corresponding DY at position X is: n _DY=Y n -Y0.

[0046] 2) Y-axis straightness Y_DX measurement

[0047] Find the straight line process in the Y direction of the Pattern glass near the head position of Y=0, move the Y axis (dot matrix) in the positive direction at equal intervals, and the X direction position X0 of the straight line edge in the microscope field of view at the starting Y0 position and the current Y n Position microscope straight edge X direction position X n The difference is Y_DX. Record each Y position and the corresponding DX until the end, throughout the Y direction of the glass.

[0048] The corresponding DX at the Y position is: n _DX=X n -X0.

[0049] Figure 3 A schematic diagram of the linearity measurement process of the X-axis and the Y-axis according to an embodiment of the present invention is shown.

[0050] 2. X and Y axis linear measurement

[0051] 1) X-axis linearity X_DX measurement

[0052] Starting from the first panel in the pattern glass near the head position X=0, move the X axis (dot matrix) in the positive direction at equal intervals. The X direction position X0 of the straight edge in the microscope field of view at the starting X0 position and the current X n Position microscope straight edge X direction position X n The difference is X_DX. Record each X position and the corresponding DX until the end, throughout the X direction of the glass.

[0053] The corresponding DX under X position is: X n _DX=X n -X0.

[0054] 2) Y-axis linearity Y_DY measurement

[0055] Starting from the first panel in the pattern glass near the Y=0 head position, move the Y axis (dot matrix) in the positive direction at equal intervals. The Y direction position Y0 of the straight line edge in the microscope field of view at the starting Y0 position and the current Y n Position Y direction position of the straight edge in the microscope n The difference is Y_DY. Record each Y position and the corresponding DY until the end, throughout the Y direction of the glass.

[0056] The corresponding DY at the Y position is: n _DY=Y n -Y0.

[0057] Figure 4 A schematic diagram of the linearity measurement process of the X-axis and the Y-axis according to an embodiment of the present invention is shown.

[0058] 3. X and Y axis vertical measurement

[0059] Taking the X-axis as the reference axis, theoretically the Y-axis should be perpendicular to the X-axis when moving, but in reality there is an angle that is not equal to 90°; there is an angle between each X position and the Y direction. If the two are not perpendicular, the position (or the position between the two measurement points) should be compensated, so it is necessary to test the verticality of the subdivided position. Find the horizontal straight line process on the glass plate that can run through the Y-axis travel, calculate the offset of the horizontal straight line edge at the first (x1, y1) and the last (x2, y2) positions on the microscope field of view, and then calculate the vertical parameters based on the trigonometric function relationship.

[0060] Figure 5 A schematic diagram of the vertical measurement process between the X-axis and the Y-axis according to an embodiment of the present invention is shown. Figure 5 For the model, the relationship between the actual and theoretical verticality of the X and Y axes can be expressed by the formula: Tan(θ)=(y2-y1) / (x2-x1).

[0061] In different Y n In the axis coordinates, they all correspond to X n There is a deviation value in the axial direction, namely: Δx n =y n *Tan(θ) n .

[0062] 4. Deviation Performance Linear Combination

[0063] In this system, the deviation of the axis is mainly composed of the three components of straightness, linearity and perpendicularity mentioned above, which are independent and superimposable, and conform to the characteristics of linear system. Therefore, the deviation composition can be expressed by the formula:

[0064] ΔE(n)=ΔE1(n)+ΔE2(n)+ΔE3(n)

[0065] ΔE1(n) is the linearity deviation, ΔE2(n) is the straightness deviation, and ΔE3(n) is the perpendicularity deviation.

[0066] 1) If Figure 6 As shown, the compensation value in the X direction is: ΔE X (n) = (X n -DX)+(Y n -DX)+y t *Tan(θ) n

[0067] Where: ΔE1(n) = X n -DX; ΔE2(n)=Y n -DX; ΔE3(n) = y t *Tan(θ) n

[0068] 2) If Figure 7 As shown, the compensation value in the Y direction is: ΔE Y (n)=(Y n -DY)+(X n -DY)

[0069] Where: ΔE1(n)=Y n -DY; ΔE2(n) = X n -DY; ΔE3(n)=0

[0070] 5. Online compensation of 2D motion

[0071] 1) Save the above measured data in a document;

[0072] 2) Target value of machine coordinates (X tx ,Y ty ), by calling the document, find X tx , Y ty Front and back (left and right) adjacent coordinates (X tx-1 ,Y ty-1 ) and (X tx+1 ,Y ty+1 ), and the corresponding deviation values ​​under each factor can be found (EX tx-1 ,EY ty-1 ) and (EX tx+1 ,EY ty+1 );

[0073] 3) When measuring performance, there is a certain subdivision (matrix density). The linear interpolation method is used to supplement the two corresponding deviation values ​​adjacent to each other to obtain the specific compensation value under this value.

[0074] Calculate the X-direction compensation value by linear interpolation method:

[0075] EX tx =(X tx -X tx-1 )*(EX tx+1 -EX tx-1 ) / (X tx+1 -X tx-1 )

[0076] Calculate the Y direction compensation value by linear interpolation method:

[0077] EY ty =(Y ty -Y ty-1 )*(EY ty+1 -EY ty-1 ) / (Y ty+1 -Y ty-1 )

[0078] 4) Superimpose the three deviations and add them to the target value, and the actual moving position (X a ,Y a ) is the target position after the deviation is superimposed.

[0079] The deviation after superposition is EX tx , after compensation in X direction:

[0080] X a =X tx +EX tx

[0081] The deviation after superposition is EY ty , after compensation in the Y direction:

[0082] Y a =Y ty +EY ty

[0083] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A positioning compensation method for a display panel camera, characterized in that: include: Measuring the straightness and linearity of the X-axis and Y-axis of the camera, as well as the verticality between the X-axis and the Y-axis; wherein the X-axis is the extension direction of the display panel clamping mechanism, and the Y-axis is the extension direction of the camera, and the camera is installed across the two sides of the clamping mechanism to take pictures of the display panel; The deviation of the straightness of the X-axis and the Y-axis, the deviation of the linearity, and the deviation of the perpendicularity between the X-axis and the Y-axis are linearly combined, and then the X-axis and the Y-axis are compensated and corrected to perform positioning compensation for the camera.

2. A positioning compensation method for a display panel camera according to claim 1, characterized in that: The microscope is mounted on the camera, the camera can move back and forth on the X-axis along the slide rail, and the microscope can move back and forth in the Y-axis direction along the slide rail.

3. The positioning compensation method of a display panel camera according to claim 1, characterized in that: In the measurement, Pattern glass is used as a measuring tool. The interior of the Pattern glass has horizontal and vertical straight line standard processes and has a regular panel distribution.

4. The positioning compensation method of a display panel camera according to claim 3, characterized in that: The measuring of the straightness of the X-axis and the Y-axis comprises: 1) X-axis straightness X_DY measurement Find the straight line process in the X direction of the Pattern glass near the head position of X=0, move the X axis in the positive direction at equal intervals, and compare the Y direction position Y0 of the straight line edge in the microscope field of view at the starting X0 position with the current X n Position Y direction position of the straight edge in the microscope n The difference is recorded as X_DY; record each X position and the corresponding DY until the end, through the Pattern glass X direction, where the corresponding DY at the X position is: X n _DY=Y n -Y0; 2) Y-axis straightness Y_DX measurement Find the straight line process in the Y direction of the Pattern glass near the head position of Y=0, move the Y axis in the positive direction at equal intervals, and compare the X direction position X0 of the straight line edge in the microscope field of view at the starting Y0 position with the current Y n Position microscope straight edge X direction position X n The difference is recorded as Y_DX; record each Y position and the corresponding DX until the end, throughout the Y direction of the Pattern glass; where the corresponding DX at the Y position is: Y n _DX=X n -X0.

5. The positioning compensation method of a display panel camera according to claim 3, characterized in that: The linearity of the X-axis and Y-axis is measured, including: 1) X-axis linearity X_DX measurement Starting from the first panel in the pattern glass near the head position X=0, move the X axis in the positive direction at equal intervals to make the X direction position X0 of the straight edge in the microscope field of view at the starting X0 position and the current X n Position microscope straight edge X direction position X n The difference is recorded as X_DX; record each X position and the corresponding DX until the tail, through the X direction of the glass; where the corresponding DX at the X position is: X n _DX=X n -X0; 2) Y-axis linearity Y_DY measurement Starting from the first panel in the pattern glass near the Y=0 head position, move the Y axis in the positive direction at equal intervals to make the Y direction position Y0 of the straight line edge in the microscope field of view at the starting Y0 position and the current Y n Position Y direction position of the straight edge in the microscope n The difference is recorded as Y_DY; record each Y position and the corresponding DY until the tail, through the Y direction of the glass; where the corresponding DY at the Y position is: Y n _DY=Y n -Y0.

6. The positioning compensation method of a display panel camera according to claim 3, characterized in that: The measuring of the perpendicularity between the X-axis and the Y-axis comprises: Find the horizontal straight line process on the glass plate that can penetrate the Y-axis travel, calculate the offset of the horizontal straight line edges at the first and last positions on the microscope field of view, and then calculate the verticality based on the trigonometric function relationship.

7. The positioning compensation method of a display panel camera according to claim 3, characterized in that: The linear combination of the straightness deviation of the X-axis and the Y-axis, the linearity deviation, and the perpendicularity deviation between the X-axis and the Y-axis comprises: The deviation components of the X-axis and Y-axis are expressed by the formula: ΔE(n)=ΔE1(n)+ΔE2(n)+ΔE3(n) ΔE1(n) is the linearity deviation, ΔE2(n) is the straightness deviation, and ΔE3(n) is the perpendicularity deviation.

8. The positioning compensation method of a display panel camera according to claim 3, characterized in that: The compensation and correction of the X-axis and the Y-axis to perform positioning compensation of the camera includes: 1) Save the above measured data in a document; 2) Target value (X) of the camera's platform coordinates tx ,Y ty ), by calling the document, find X tx , Y ty The adjacent coordinates (X tx-1 ,Y ty-1 ) and (X tx+1 ,Y ty+1 ), and the corresponding deviation value of the adjacent coordinates can be found (EX tx-1 ,EY ty-1 ) and (EX tx+1 ,EY ty+1 ); 3) Compensating the corresponding deviation values ​​of the adjacent coordinates by linear interpolation to obtain a specific compensation value under the deviation value; 4) Superimpose the three deviations and add them to the target value to obtain the actual moving position.

9. A positioning compensation method for a display panel camera according to claim 8, characterized in that: The specific compensation value is calculated as follows: Calculate the X-direction compensation value by linear interpolation method: EX tx =(X tx -X tx-1 )*(EX tx+1 -EX tx-1 ) / (X tx+1 -X tx-1 ) Calculate the Y direction compensation value by linear interpolation method: HEY ty (And ty -AND ty-1 )*(HEY ty+1 -HEY ty-1 ) / (AND ty+1 -AND ty-1 )。 10. The positioning compensation method of a display panel camera according to claim 9, characterized in that: The actual moving position is calculated as follows: The deviation after superposition is EX tx , after compensation in X direction: X a =X tx +EX tx The deviation after superposition is EY ty , after compensation in Y direction: AND a =And ty +EY ty 。

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