Microlens array multi-point alignment focusing method, storage medium and electronic equipment

Abstract

The invention provides a micro-lens array multi-point alignment focusing method, a storage medium and electronic equipment, and relates to the technical field of lens array detection. According to the algorithm, three unit lens point positions which are far away from each other on an actual array lens sample piece are selected as reference input points, after reference coordinates and actual coordinates are obtained, a vector length scaling coefficient, xy-direction offset and a rotation angle are calculated in sequence, then a conversion matrix is obtained through plane fitting, and the conversion matrix is calculated. And finally, accurate alignment and focusing of any reference point and an actual product point in the xyz three directions are realized. The method does not need to consider the rotation direction and the deviation angle of sample placement, is high in adjacent point test positioning and movement completion speed, has the characteristics of high precision, simplicity in implementation, low cost and the like, and effectively solves the problems of low lens positioning and focusing efficiency, insufficient precision, complex calculation and the like of a traditional micro lens array unit. The micro-lens array is suitable for various application scenes depending on the micro-lens array, such as optical sensing, 3D imaging and the like.

Description

Technical Field

[0001] This invention relates to the field of lens array detection technology, specifically to a multi-point alignment and focusing method for a microlens array, a storage medium, and an electronic device. Background Technology

[0002] Microlens arrays are optical elements composed of a large number of micro- and nano-scale spherical or freeform surface unit lenses. They modify the propagation direction and wave phase of incident light through surface relief structures or refraction principles, thereby achieving precise control of the light beam. Due to their small unit size, high integration, and support for large field of view and infinite depth of field, microlens arrays can form a variety of novel optical systems, accomplishing functions that traditional optical elements cannot achieve. They have become indispensable core optical components in many fields such as optical sensing, lidar, light field cameras, optical microscopes, high-throughput maskless lithography, 3D imaging, and stereoscopic displays.

[0003] Microlens arrays typically consist of thousands or even tens of thousands of unit lenses. During design, the sag, aperture, curvature, and other parameters of each unit lens are fixed values, and the spacing between adjacent unit lenses is generally consistent. However, limited by current manufacturing processes, the curvature and focal length of unit lenses are difficult to control precisely. The surface contours of some unit lenses may even be damaged during processing. Therefore, it is necessary to inspect the parameters of each unit lens individually to determine if the product meets standards. However, the aperture of a unit lens is typically less than 1 millimeter, its height is only 10-60 micrometers, and the spacing between adjacent unit lenses is tens to hundreds of micrometers. This makes the precise positioning and focusing of each unit lens a core technical challenge in the microlens array testing process.

[0004] In the existing technology, the positioning and focusing methods of microlens array unit lenses mainly have the following drawbacks:

[0005] 1. Manual Alignment Method: This method involves manually operating a microscope to align each design point with the actual sample point according to the design reference coordinate file. This method is extremely inefficient and costly due to its manual operation, and cannot meet the inspection requirements of large-scale microlens arrays.

[0006] 2. Fixture positioning method: The sample is fixed and positioned by a special fixture. However, the machining accuracy and assembly error of the fixture will directly affect the positioning accuracy, and it is often difficult to achieve the high precision requirements of microlens array detection.

[0007] 3. Visual sensor recognition method: This method uses a camera or other visual sensor to capture images of an array of lenses, and then processes the images to obtain the specific location of the points. However, due to differences in the shooting angle of the visual sensor, there is a matching deviation between the coordinates obtained from image processing and the spatial coordinates, resulting in errors in the scanned points. Furthermore, this method involves a cumbersome calibration process, a large amount of computation during measurement, and limited detection efficiency.

[0008] 4. Dimensional limitations: The above methods are only for the coordinate alignment of the lens in the xy direction. However, in actual detection, it is also necessary to find the focal surface of the lens and restore the surface shape through the interference algorithm to detect the complete parameters of the unit lens. Existing methods cannot achieve accurate alignment and focusing in the xyz directions at the same time.

[0009] Therefore, existing technologies need to be improved. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a multi-point alignment and focusing method for microlens arrays, a storage medium, and an electronic device. This algorithm selects three reference points and their corresponding actual point coordinates to calculate the offsets and transformation matrices in the x, y, and z directions. This enables rapid and accurate alignment and focusing of any reference point with the actual product point, without needing to consider the sample's rotation direction, offset angle, or axis stepping accuracy. It offers advantages such as high accuracy, fast speed, simple implementation, and low cost.

[0011] This invention is achieved through the following technical solution:

[0012] In a first aspect, the present invention provides a multi-point alignment and focusing method for a microlens array, comprising the following steps:

[0013] S1. Selecting reference points and obtaining actual point coordinates: Select the xy coordinates of individual unit lenses at three edge corners from the design reference coordinate file as the xy coordinates of reference points Pref1, Pref2, and Pref3, and set the z-direction coordinates of the reference points to 1; manually obtain the xyz coordinates of the actual points Preal1, Preal2, and Preal3 corresponding to the above reference points after the array lens sample is fixed.

[0014] S2. Calculate the scaling factor S: Select the diagonal reference points Pref2 and Pref3 with the largest interval and the corresponding actual points Preal2 and Preal3. Calculate the reference point vector Vref23 and the actual point vector Vreal23 respectively. Then calculate the lengths of the two vectors to obtain the reference point vector length Lref23 and the actual point vector length Lreal23. Use the formula S=Lref23 / Lreal23 to obtain the scaling factor S. Multiply the actual points Preal1, Preal2, and Preal3 by S to obtain Preal_1, Preal_2, and Preal_3.

[0015] S3. Calculate the xy-direction offsets delx, dely, and the offset angle theta: Based on the actual point vector Vreal_23 composed of Vref23 and Preal_2, Preal_3, extract the xy-axis coordinates of the two to form Vref23_xy and Vreal_23_xy, calculate theta using the dot product formula, and then calculate delx and dely using polar coordinate transformation.

[0016] S4. Calculate the actual point xy direction coordinate matrix Pxy: Construct the xy offset matrix A, and multiply the reference point matrix input by A to obtain Pxy;

[0017] S5. Obtaining xyz direction parameters by plane fitting: Combine Pxy with the z-axis data of Preal_1, Preal_2, and Preal_3 to form the xyz matrix Pxyz. Use the least squares method to fit the parameters a, b, and c in the plane equation Z=aX+bY+c.

[0018] S6. Construct the xyz transformation matrix H and calculate the actual coordinates: Integrate the xy direction parameters obtained in step S3 and the z direction parameters obtained in step S5 to construct the transformation matrix H. After the coordinates of any reference point are transformed by H, divide by S to obtain the xyz coordinates of the corresponding actual point, thus achieving alignment and focus.

[0019] Furthermore, in this invention, the reference point vector in step S2 above is calculated as follows:

[0020] Vref23=(Pref2_x-Pref3_x, Pref2_y-Pref3_y, Pref2_z-Pref3_z),

[0021] The actual point vector is calculated in step S2 as follows:

[0022] Vreal23=(Preal2_x-Preal3_x, Preal2_y-Preal3_y, Preal2_z-Preal3_z),

[0023] In step S2, the lengths of the reference point and the actual point vectors are calculated as follows:

[0024] Lref23=sqrt(Vref23_x²+Vref23_y²+Vref23_z²),

[0025] Lreal23=sqrt(Vreal23_x²+Vreal23_y²+Vreal23_z²),

[0026] The sqrt(*) function represents the square root operation.

[0027] Furthermore, in this invention, the dot product formula in step S3 above is:

[0028] theta=arccos[(Vref23_xy·Vreal_23_xy) / (|Vref23_xy|×|Vreal_23_xy|)],

[0029] The xy coordinate vectors of the reference point and the actual point are represented as follows:

[0030] Vref23_xy=(Pref2_x-Pref3_x, Pref2_y-Pref3_y),

[0031] Vreal_23_xy=(Preal_2_x-Preal_3_x, Preal_2_y-Preal_3_y),

[0032] In the dot product formula:

[0033] Vref23_xy×Vreal_23_xy=Vref23_x×Vreal_23_x+Vref23_y×Vreal_23_y,

[0034] |Vref23_xy|=sqrt(Vref23_x²+Vref23_y²),

[0035] |Vreal_23_xy|=sqrt(Vreal_23_x²+Vreal_23_y²).

[0036] Furthermore, in this invention, the formula for calculating the offset in the polar coordinate transformation in step S3 above is:

[0037] delx=Vreal_23_x-[Vref23_x×cos(theta)-Vref23_y×sin(theta)],

[0038] dely=Vreal_23_y-[Vref23_x×sin(theta)+Vref23_y×cos(theta)].

[0039] Furthermore, in this invention, the xy offset matrix in step S4 above is:

[0040] ,

[0041] Where T represents matrix transpose;

[0042] The reference point matrix is:

[0043] ,

[0044] Where Pref1_z, Pref2_z, and Pref3_z are all 1; the true xy coordinates Pxy = input × A, Pxy is a 3 × 2 two-dimensional matrix, where × represents matrix multiplication.

[0045] Furthermore, in this invention, the xyz matrix Pxyz in step S5 above is as follows:

[0046] Pxyz=[Pxy(1,:),Preal1_z;Pxy(2,:),Preal2_z;Pxy(3,:),Preal3_z],

[0047] Where Pxy(*,:) represents the *th row of data in Pxy;

[0048] The least squares method calculation in step S5 is as follows:

[0049] The coefficient matrix H1 = [X; Y; ones(3)],

[0050] , , ,

[0051] ones(3) represents a 1×3 one-dimensional array where all values ​​are 1.

[0052] coefficient .

[0053] Furthermore, in this invention, the xyz transformation matrix H in step S6 above is as follows:

[0054] H=[cos(theta),-sin(theta),delx;sin(theta),cos(theta),dely;p1,p2,p3],

[0055] Where p1 = a × cos(theta) + b × sin(theta),

[0056] p2=b×cos(theta)-a×sin(theta),

[0057] p3 = a × delx + b × dely + c;

[0058] The actual coordinates of any reference point p=(x,y,z) , where . / means that each element of the matrix is ​​divided by S.

[0059] Furthermore, in this invention, the three reference points selected in step S1 are the unit lenses corresponding to three of the four corners of the array lens sample, and the three reference points are far apart to avoid the accumulation of movement errors.

[0060] In a second aspect, the present invention also provides a computer-readable storage medium storing a computer program thereon, wherein when the computer program is executed by a processor, it implements the steps of the microlens array multi-point alignment focusing method described in any one of the preceding claims.

[0061] Thirdly, the present invention also provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the microlens array multi-point alignment focusing method described in any one of the above claims. The electronic device also includes an xyz three-axis displacement stage control module, an imaging module data receiving module, and a laser displacement sensor data acquisition module connected to the processor, for realizing sample movement control and coordinate data acquisition.

[0062] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0063] 1. By using mathematical methods such as vector calculation, matrix transformation and least squares plane fitting, the scaling, rotation and translation deviations of the reference coordinates and the actual coordinates in the xyz directions are fully considered, achieving micron-level positioning and focusing accuracy and meeting the detection requirements of microlens arrays.

[0064] 2. The positioning and movement of adjacent point tests can be completed in tens of milliseconds, which greatly improves the detection efficiency of microlens arrays and is suitable for rapid detection of large-scale microlens arrays;

[0065] 3. No complicated calibration process or special fixtures are required. Only three reference points need to be selected and their actual coordinates obtained. The transformation matrix can be automatically calculated by the algorithm, making the operation process simple.

[0066] 4. It does not require consideration of the actual rotation direction, offset angle, and axis stepping accuracy of the sample, and can adapt to sample inspection under different placement conditions, reducing the accuracy requirements of the inspection platform;

[0067] 5. It does not require high-precision vision sensors or special fixtures; it only requires conventional displacement sensors and a detection platform, which significantly reduces the investment cost of detection equipment.

[0068] 6. It simultaneously achieves automatic alignment and focusing in the x, y, and z directions, which can directly provide a precise focus plane position for subsequent surface restoration and parameter detection, overcoming the limitation of existing technologies that can only achieve alignment in the x and y directions. Attached Figure Description

[0069] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0070] Figure 1 This is a flowchart illustrating the overall steps of the present invention;

[0071] Figure 2 This is a flowchart of the transformation matrix calculation process of the present invention;

[0072] Figure 3 This is a partial view of the reference coordinate region for the array lens of the present invention. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for explanation only and are not intended to limit the invention. The following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0074] Example 1

[0075] This embodiment 1 provides a multi-point alignment and focusing method for a microlens array, such as... Figure 1 , Figure 2 and Figure 3 As shown, the algorithm in this embodiment 1 achieves automatic alignment and focusing of a large number of points in the microlens array through the following process:

[0076] S1, Selecting reference points and obtaining actual point coordinates: First, select the xy coordinates of the individual unit lens at the three edge corners of the design reference coordinate file as the reference point xy coordinates. Since the reference coordinate file does not have z-direction coordinates, the z-direction coordinates of the reference points are assumed to be at the same height and uniformly set to 1. This facilitates the calculation of the xy-direction coordinate matrix Pxy in the subsequent step S4. At the same time, manually obtain the actual point xyz coordinates corresponding to the reference points after the array lens sample is fixed. Name the reference points Pref1, Pref2, and Pref3, and name the actual points Preal1, Preal2, and Preal3.

[0077] S2, Calculate the scaling factor S: Select the diagonal reference points Pref2 and Pref3 with the largest interval and the corresponding actual points Preal2 and Preal3. Calculate the reference point vector Vref23 and the actual point vector Vreal23 respectively. Calculate the lengths of the two vectors to obtain the reference point vector length Lref23 and the actual point vector length Lreal23. Obtain the scaling factor S by the ratio of the two (S=Lref23 / Lreal23). Multiply the actual points Preal1, Preal2, and Preal3 by the scaling factor S to obtain the actual point coordinates Preal_1, Preal_2, and Preal_3 to be used later.

[0078] S3, calculate the xy-direction offsets delx and dely, and the offset angle theta: Calculate the actual point vector Vreal_23 based on Vref23 and Preal_2, Preal_3, extract the xy-axis coordinates of Vref23 and Vreal_23 to form Vref23_xy and Vreal_23_xy, calculate the offset angle theta using the dot product formula, and then obtain the xy-direction offsets delx and dely using the polar coordinate transformation method;

[0079] S4, calculate the xy coordinate matrix Pxy of the actual point: construct the xy offset matrix A using the offset and offset angle obtained above, and multiply the reference point matrix input with A to obtain Pxy, that is, calculate the xy coordinate matrix Pxy corresponding to the actual point for reference points Pref1, Pref2, and Pref3.

[0080] S5, plane fitting to obtain xyz direction parameters: Pxy and the z-axis data of the actual points Preal_1, Preal_2, and Preal_3 are combined to form a new xyz matrix Pxyz. The parameters a, b, and c in the plane equation Z=aX+bY+c are obtained by fitting with the least squares method; that is, the slope [a,b] and offset c in the xy direction are obtained.

[0081] S6. Construct the xyz transformation matrix H and calculate the actual coordinates: Finally, by integrating the xy offset and offset angle, as well as the xy slope and offset obtained from the above calculations, the final xyz transformation matrix H is obtained. For any reference lens coordinate, multiply it by the transformation matrix H and then divide it by the scaling factor S to obtain the coordinate parameters corresponding to the actual sample point, thus realizing the alignment and focusing functions.

[0082] In step S2 above, the reference point vector and the actual point vector are calculated as follows:

[0083] Vref23=(Pref2_x-Pref3_x, Pref2_y-Pref3_y, Pref2_z-Pref3_z);

[0084] Vreal23=(Preal2_x-Preal3_x, Preal2_y-Preal3_y, Preal2_z-Preal3_z);

[0085] It should be noted that the labels _x, _y, and _z represent the x, y, and z coordinate values ​​of the corresponding points, and the subsequent coordinate naming is the same.

[0086] In step S2, the vector lengths of the reference point and the actual point, and the scaling factor S are calculated as follows:

[0087] Lref23=sqrt(Vref23_x 2 +Vref23_y 2 +Vref23_z 2 ),

[0088] Lreal23=sqrt(Vreal23_x²+Vreal23_y²+Vreal23_z²),

[0089] S = Lref23 / Lreal23;

[0090] The sqrt(*) function calculates the square root of the asterisk (*).

[0091] The dot product formula calculation method in step S3 is as follows:

[0092] The offset angle theta in the xy direction:

[0093] theta=arccos[(Vref23_xy·Vreal_23_xy) / |Vref23_xy|×|Vreal_23_xy|];

[0094] The xy coordinate vectors of the reference point and the actual point are represented as follows:

[0095] Vref23_xy=(Vref23_x,Vref23_y)=(Pref2_x-Pref3_x, Pref2_y-Pref3_y);

[0096] Vreal_23_xy=(Vreal_23_x,Vreal_23_y)=(Preal_2_x-Preal_3_x, Preal_2_y-Preal_3_y);

[0097] In the dot product formula:

[0098] Vref23_xy×Vreal_23_xy=Vref23_x×Vreal_23_x+Vref23_y×Vreal_23_y,

[0099] |Vref23_xy|=sqrt(Vref23_x 2 +Vref23_y 2 );

[0100] |Vreal_23_xy|=sqrt(Vreal_23_x 2 +Vreal_23_y 2 );

[0101] The polar coordinate transformation calculation method in step S3 is as follows:

[0102] Vref23_x=r×cos(phi);

[0103] Vref23_y=r×sin(phi);

[0104] Where r = |Vref23_xy|; phi represents the offset angle in polar coordinates;

[0105] Vreal_23_x=r×cos(phi+theta)+delx;

[0106] Vreal_23_y=r×sin(phi+theta)+dely;

[0107] The offset angle theta in the xy direction has been calculated; delx and dely represent the offsets in the x and y directions, respectively.

[0108] The expansions of r×cos(phi+theta) and r×sin(phi+theta) can be expressed as:

[0109] r×cos(phi+theta)=Vref23_x×cos(theta)-Vref23_y×sin(theta);

[0110] r×sin(phi+theta)=Vref23_x×sin(theta)+Vref23_y×cos(theta);

[0111] Therefore, the formula for calculating the offset is:

[0112] delx=Vreal_23_x-[Vref23_x×cos(theta)-Vref23_y×sin(theta)];

[0113] dely=Vreal_23_y–[Vref23_x×sin(theta)+Vref23_y×cos(theta)];

[0114] The formula A for the xy offset matrix in step S4 is as follows:

[0115] ;

[0116] Where T represents the transpose of the matrix;

[0117] The reference point matrix input is a 3×3 two-dimensional matrix as follows:

[0118] ;

[0119] Where Pref1_z, Pref1_z, and Pref1_z are all 1;

[0120] The true xy coordinates Pxy = input × A; Pxy is a 3 × 2 two-dimensional matrix, where × represents matrix multiplication;

[0121] In step S5, the xyz matrix Pxyz is represented as follows:

[0122] Pxyz=[Pxy(1,:),Preal1_z;Pxy(2,:),Preal2_z;Pxy(3,:),Preal3_z];

[0123] Where Pxy(*,:) represents the *th row of data in Pxy.

[0124] The least squares calculation in step S5 is as follows:

[0125] The formula for the plane is Z = aX + bY + c;

[0126] in , , ,Pxyz(:,*) represents the *th column of Pxyz;

[0127] The coefficient matrix H1 = [X; Y; ones(3)]; where ones(3) represents a 1×3 one-dimensional array where all values ​​are 1;

[0128] coefficient ;

[0129] The method for calculating the xyz transformation matrix H in step 6 is as follows:

[0130] a) First, the true coordinates in the xy direction are obtained by step S3, and their representation is as follows:

[0131] x_real=x_ref×cos(theta)–y_ref×sin(theta)+delx;

[0132] y_real=x_ref×sin(theta)+y_ref×cos(theta)+dely;

[0133] Where x_ref, y_ref, x_real, and y_real represent the x and y coordinates of the reference point and the calculated actual point, respectively.

[0134] b) Then, using the plane equation formula in step S5:

[0135] Z = aX + bY + c; Substituting the x_real and y_real values ​​calculated in a) into the formula, we get:

[0136] z_real=a×x_real+b×y_real+c=x_ref×(a×cos(theta)+b×sin(theta))+y_ref×(b×cos(theta)-a×sin(theta))+a×delx+b×dely+c;

[0137] Let p1 = a × cos(theta) + b × sin(theta); p2 = b × cos(theta) - a × sin(theta); p3 = a × delx + b × delly + c; therefore, the final transformation matrix H is expressed as follows:

[0138] H=[cos(theta),-sin(theta),delx; sin(theta),cos(theta),dely;p1,p2,p3];

[0139] c) For any reference point p=(x,y,z); its corresponding actual point coordinates (x',y',z') are finally calculated as follows:

[0140] Here, × indicates matrix multiplication, and . / indicates that each element of the matrix result is divided by the scaling factor S.

[0141] The principle of this algorithm is as follows:

[0142] 1. Sample Fixing: The microlens array sample is fixed on the stage of the xyz triaxial displacement stage using a clamp to ensure that the sample does not shift during the testing process;

[0143] 2. Reference point selection and coordinate acquisition:

[0144] From the design reference coordinate file, select three unit lenses corresponding to the four corners of the sample as reference points Pref1, Pref2, and Pref3, with their xy coordinates being Pref1(0mm, 0mm), Pref2(0mm, 50mm), and Pref3(50mm, 50mm), respectively, and their z coordinates being set to 1.

[0145] An industrial computer controls a three-axis (xyz) displacement stage to move a CMOS camera and a laser displacement sensor to the areas corresponding to three reference points. The camera imaging identifies the position of the actual unit lens, and the laser displacement sensor measures the height in the z-direction to obtain the xyz coordinates of the actual points Preal1, Preal2, and Preal3.

[0146] Assume the measurements are: Preal1 (0.02mm, 0.03mm, 0.5mm), Preal2 (0.01mm, 50.02mm, 0.52mm), Preal3 (50.03mm, 50.01mm, 0.48mm);

[0147] 3. Calculation of scaling factor:

[0148] Calculate the reference point vector Vref23 = (0mm-50mm, 50mm-50mm, 1-1) = (-50mm, 0mm, 0mm).

[0149] The actual point vector Vreal23 = (0.01mm - 50.03mm, 50.02mm - 50.01mm, 0.52mm - 0.48mm) = (-50.02mm, 0.01mm, 0.04mm);

[0150] Calculate the vector length: Lref23 = sqrt((-50)² + 0² + 0²) = 50 mm.

[0151] Lreal23=sqrt((-50.02)²+0.01²+0.04²)≈50.02000041mm;

[0152] The scaling factor S = 50 / 50.02000041 ≈ 0.99959998;

[0153] The actual point coordinates after scaling:

[0154] Preal_1=(0.02×0.99959998, 0.03×0.99959998, 0.5×0.99959998)≈(0.019992mm, 0.029988mm, 0.4998mm);

[0155] Preal_2≈(0.009996mm, 50.0000002mm, 0.519792mm);

[0156] Preal_3≈(50.010002mm, 50.0000002mm, 0.479808mm);

[0157] 4. Calculation of offset and offset angle in the x and y directions:

[0158] Extract the two-dimensional vector: Vref23_xy=(-50mm, 0mm), Vreal_23_xy=(50.010002mm-0.009996mm, 50.0000002mm-50.0000002mm)=(50.000006mm, 0mm);

[0159] Calculate the dot product: Vref23_xy·Vreal_23_xy=(-50)×50.000006+0×0=-2500.0003mm²;

[0160] Calculate the vector magnitude: |Vref23_xy|=50mm, |Vreal_23_xy|≈50.000006mm;

[0161] The offset angle theta = arccos[(-2500.0003) / (50×50.000006)] ≈ arccos(-0.99999988) ≈ 179.9999° (due to a slight rotation during sample placement, the angle here is close to 180°).

[0162] Calculate the offset: delx = 50.000006 - [(-50) × cos(179.9999°) - 0 × sin(179.9999°)] ≈ 50.000006 - [(-50) × (-0.99999988) - 0] ≈ 0.000006 mm; dely = 0 - [(-50) × sin(179.9999°) + 0 × cos(179.9999°)] ≈ 0 mm;

[0163] 5. Calculation of xy-direction coordinate matrix:

[0164] 1. Construct the xy offset matrix ;

[0165] Reference point matrix ;

[0166] calculate

[0167] Pxy=input×A≈[[0.000006mm,0mm],[50.000006mm,0mm],[0.000006mm,50.000006mm]];

[0168] 6. Plane fitting and construction of xyz transformation matrix:

[0169] Constructing the xyz matrix

[0170] Pxyz=[[0.000006mm,0mm,0.4998mm],[50.000006mm,0mm,0.519792mm],[0.000006mm,50.000006mm,0.479808mm]];

[0171] extract

[0172] ,

[0173] ,

[0174] ;

[0175] Construct the coefficient matrix H1:

[0176] H1=[X; Y; ones(3)]=[[0.000006,50.000006,0.000006],[0,0,50.000006],[1,1,1]];

[0177] The following values ​​were obtained using the least squares method: a≈0.0004, b≈-0.0004, c≈0.4998mm;

[0178] Calculate p1 = 0.0004 × (-0.99999988) + (-0.0004) × 0.00000523 ≈ -0.0004; p2 = (-0.0004) × (-0.99999988) - 0.0004 × 0.00000523 ≈ 0.0004; p3 = 0.0004 × 0.000006 + (-0.0004) × 0 + 0.4998 ≈ 0.4998 mm;

[0179] Construct the xyz transformation matrix H:

[0180] H≈

[0181] [[-0.99999988,-0.00000523,0.000006],[0.00000523,-0.99999988,0],[-0.0004,0.0004,0.4998]];

[0182] 7. Actual coordinate calculation and alignment / focusing:

[0183] Select a reference point p=(25mm, 25mm, 1) for any unit lens in the reference coordinate file, and calculate its corresponding actual point coordinates:

[0184] ;

[0185] An industrial computer controls a three-axis (xyz) displacement stage to move to the actual coordinate position. The height in the z-direction fed back by the laser displacement sensor is consistent with the calculated value, and the CMOS camera produces a clear image, indicating that precise alignment and focusing have been achieved.

[0186] Example 2

[0187] This embodiment 2 provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the steps of the microlens array multi-point alignment focusing method in embodiment 1.

[0188] Example 3

[0189] This embodiment 3 provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the microlens array multi-point alignment focusing method of embodiment 1. The electronic device also includes an xyz three-axis displacement stage control module, an imaging module data receiving module, and a laser displacement sensor data acquisition module connected to the processor, which are used to realize sample movement control and coordinate data acquisition.

[0190] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-point alignment and focusing method for a microlens array, characterized in that, Includes the following steps, S1. Selecting reference points and obtaining actual point coordinates: Select the xy coordinates of individual unit lenses at three edge corners from the design reference coordinate file as the xy coordinates of reference points Pref1, Pref2, and Pref3, and set the z-direction coordinates of the reference points to 1; manually obtain the xyz coordinates of the actual points Preal1, Preal2, and Preal3 corresponding to the above reference points after the array lens sample is fixed. S2. Calculate the scaling factor S: Select the diagonal reference points Pref2 and Pref3 with the largest interval and the corresponding actual points Preal2 and Preal3. Calculate the reference point vector Vref23 and the actual point vector Vreal23 respectively. Then calculate the lengths of the two vectors to obtain the reference point vector length Lref23 and the actual point vector length Lreal23. Use the formula S=Lref23 / Lreal23 to obtain the scaling factor S. Multiply the actual points Preal1, Preal2, and Preal3 by S to obtain Preal_1, Preal_2, and Preal_3. S3. Calculate the xy-direction offsets delx, dely, and the offset angle theta: Based on the actual point vector Vreal_23 composed of Vref23 and Preal_2, Preal_3, extract the xy-axis coordinates of the two to form Vref23_xy and Vreal_23_xy, calculate theta using the dot product formula, and then calculate delx and dely using polar coordinate transformation. S4. Calculate the actual point xy direction coordinate matrix Pxy: Construct the xy offset matrix A, and multiply the reference point matrix input by A to obtain Pxy; S5. Obtaining xyz direction parameters by plane fitting: Combine Pxy with the z-axis data of Preal_1, Preal_2, and Preal_3 to form the xyz matrix Pxyz. Use the least squares method to fit the parameters a, b, and c in the plane equation Z=aX+bY+c. S6. Construct the xyz transformation matrix H and calculate the actual coordinates: Integrate the xy direction parameters obtained in step S3 and the z direction parameters obtained in step S5 to construct the transformation matrix H. After the coordinates of any reference point are transformed by H, divide by S to obtain the xyz coordinates of the corresponding actual point, thus achieving alignment and focus.

2. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The reference point vector is calculated in step S2 as follows: Vref23=(Pref2_x-Pref3_x, Pref2_y-Pref3_y, Pref2_z-Pref3_z), The actual point vector is calculated in step S2 as follows: Vreal23=(Preal2_x-Preal3_x, Preal2_y-Preal3_y, Preal2_z-Preal3_z), In step S2, the lengths of the reference point and the actual point vectors are calculated as follows: Lref23=sqrt(Vref23_x²+Vref23_y²+Vref23_z²), Lreal23=sqrt(Vreal23_x²+Vreal23_y²+Vreal23_z²), The sqrt(*) function represents the square root operation.

3. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The dot product formula in step S3 is: theta=arccos[(Vref23_xy·Vreal_23_xy) / (|Vref23_xy|×|Vreal_23_xy|)], The xy coordinate vectors of the reference point and the actual point are represented as follows: Vref23_xy=(Pref2_x-Pref3_x, Pref2_y-Pref3_y), Vreal_23_xy=(Preal_2_x-Preal_3_x, Preal_2_y-Preal_3_y), In the dot product formula: Vref23_xy×Vreal_23_xy=Vref23_x×Vreal_23_x+Vref23_y×Vreal_23_y, |Vref23_xy|=sqrt(Vref23_x²+Vref23_y²), |Vreal_23_xy|=sqrt(Vreal_23_x²+Vreal_23_y²).

4. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The formula for calculating the offset in step S3 using polar coordinate transformation is: delx=Vreal_23_x-[Vref23_x×cos(theta)-Vref23_y×sin(theta)], dely=Vreal_23_y-[Vref23_x×sin(theta)+Vref23_y×cos(theta)].

5. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The xy offset matrix in step S4 is: ， Where T represents matrix transpose; The reference point matrix is: ， Where Pref1_z, Pref2_z, and Pref3_z are all 1; The true xy coordinates are Pxy = input × A, where Pxy is a 3 × 2 two-dimensional matrix, and × represents matrix multiplication.

6. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The xyz matrix Pxyz in step S5 is as follows: Pxyz=[Pxy(1,:),Preal1_z;Pxy(2,:),Preal2_z;Pxy(3,:),Preal3_z], Where Pxy(*,:) represents the *th row of data in Pxy; The least squares method calculation in step S5 is as follows: The coefficient matrix H1 = [X; Y; ones(3)], ， ， ， ones(3) represents a 1×3 one-dimensional array where all values ​​are 1. 。 7. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The xyz transformation matrix H in step S6 is as follows: H=[cos(theta),-sin(theta),delx;sin(theta),cos(theta),dely;p1,p2,p3], Where p1 = a × cos(theta) + b × sin(theta), p2=b×cos(theta)-a×sin(theta), p3 = a × delx + b × dely + c; The actual coordinates of any reference point p=(x,y,z) , where . / means that each element of the matrix is ​​divided by S.

8. The multi-point alignment and focusing method for microlens arrays according to claim 1, characterized in that, The three reference points selected in step S1 are the unit lenses corresponding to three of the four corners of the array lens sample.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the microlens array multi-point alignment focusing method according to any one of claims 1-8.

10. An electronic device, characterized in that, The device includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the microlens array multi-point alignment focusing method according to any one of claims 1-8. The electronic device also includes an xyz three-axis displacement stage control module, an imaging module data receiving module, and a laser displacement sensor data acquisition module connected to the processor, for realizing sample movement control and coordinate data acquisition.

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