LDI lens verticality adjusting system and adjusting method

Abstract

The invention discloses an LDI lens perpendicularity adjusting system and method. The system comprises an adjusting module, a controller, a lens bearing plate, a workpiece table and a displacement sensor. The lens bearing plate and the adjusting module are provided with aligned through holes, the LDI lens is fixed in the through holes, the displacement sensor is located on the LDI lens, and the controller is electrically connected with the displacement sensor, the workpiece table and the adjusting module. Controlling the workpiece table to move among a plurality of preset position points; the displacement sensor determines the height from the lens to the workpiece table when the workpiece table is located at each preset position point; the controller receives the heights of the LDI lenses and determines the inclination angle and the inclination direction of the plane where each preset position point is located relative to the horizontal plane; and controlling an adjusting module to adjust the position of the lens according to the inclination angle and the inclination direction, so that the inclination angle is within a preset angle error range. By using the system, detection and accurate adjustment of the verticality of the LDI lens are realized.

Description

Technical Field

[0001] This invention relates to the technical field of LDI lenses, and more particularly to an LDI lens verticality adjustment system and method. Background Technology

[0002] With the rapid development of electronic products towards higher density and finer linewidth, the resolution of LDI laser direct writing equipment has become a key indicator of its performance. The quality of the equipment's resolution directly determines its competitiveness in the high-end market. Many factors influence resolution, among which the optical performance of the imaging lens and its installation accuracy within the equipment are crucial. However, in actual manufacturing and assembly processes, the perpendicularity between the imaging lens module and the adsorption platform (such as a vacuum adsorption stage) supporting the workpiece is difficult to guarantee. This can lead to a series of serious problems, such as tilting of the imaging focal plane, resulting in a sharp decrease in resolution at the edge of the field of view; trapezoidal or pincushion distortion in the projected image, causing uneven linewidth, misalignment, and other exposure defects. This not only significantly reduces the first-pass yield of products but also fundamentally restricts the equipment's ability to advance to more refined process nodes. Summary of the Invention

[0003] This invention provides an LDI lens verticality adjustment system and method, which realizes the detection and precise adjustment of the verticality of the LDI lens by calculating the tilt angle and tilt direction of the plane where each preset position point is located relative to the horizontal plane. The system is simple in logic, low in cost, and simple in structure.

[0004] In a first aspect, the present invention provides an LDI lens verticality adjustment system, including an adjustment module, a controller, a lens receiving plate, a workpiece stage, and a displacement sensor; the lens receiving plate and the adjustment module are provided with alignment through holes, the LDI lens is fixed in the through holes, the displacement sensor is located on the LDI lens, and the controller is electrically connected to the displacement sensor, the workpiece stage, and the adjustment module respectively.

[0005] The controller is used to control the movement of the workpiece stage between multiple preset position points;

[0006] The displacement sensor is used to determine the height of the LDI lens from the workpiece stage when the workpiece stage is at each preset position point;

[0007] The controller is also used to receive the heights of multiple LDI lenses and, based on each height, determine the tilt angle and tilt direction of the plane where each preset position point is located relative to the horizontal plane; and, based on the tilt angle and tilt direction, control the adjustment module to adjust the position of the LDI lens so that the tilt angle is within the preset angle error range.

[0008] Optionally, the adjustment module includes an adjustment pad and four screws; each screw is located at one of the four vertices of the adjustment pad, and the adjustment pad includes a through hole in which the LDI lens is fixed.

[0009] Secondly, the present invention provides a method for adjusting the verticality of an LDI lens, comprising:

[0010] Control the workpiece stage to move between multiple preset positions;

[0011] The height of multiple LDI lenses from the workpiece stage is determined by the displacement sensor when the workpiece stage is at each preset position point.

[0012] Based on the height of each LDI lens, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane;

[0013] Based on the tilt angle and tilt direction, the control adjustment module adjusts the position of the LDI lens so that the tilt angle is within the preset angle error range.

[0014] Optionally, based on the height of each LDI lens, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane, including:

[0015] Determine the spatial coordinates of each preset position point based on the height of each LDI lens;

[0016] Based on the spatial coordinates, determine the normal vector of the plane containing each preset location point;

[0017] Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane.

[0018] Optionally, the preset position points include a first position point, a second position point, and a third position point; the plane containing the first position point, the second position point, and the third position point is a first plane, and the normal vector of the first plane is a first normal vector;

[0019] Based on the spatial coordinates, determine the normal vector of the plane containing each preset location point, including:

[0020] Based on the spatial coordinates and the first calculation formula, the normal vector of the plane containing each preset location point is determined.

[0021] The first calculation formula is: ,in, Let A be the first normal vector, B be the position of the first normal vector in the first direction, C be the position of the first normal vector in the second direction, and C be the position of the first normal vector in the third direction. The first direction, the second direction, and the third direction are all perpendicular to each other. , , , The spatial coordinates of the first position point, The spatial coordinates of the second position point. These are the spatial coordinates of the third location point.

[0022] Optionally, based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane are determined, including:

[0023] Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, and using the second calculation formula, the tilt angle of the plane containing each preset position point relative to the horizontal plane is determined; the second calculation formula is: ,in, The tilt angle;

[0024] Based on spatial coordinates, determine the inclination direction of the plane where each preset location point is located.

[0025] Optionally, based on spatial coordinates, the tilt direction of the plane containing each preset location point is determined, including:

[0026] Based on the magnitudes of A and B, determine the inclination direction of the plane containing each preset location point.

[0027] Optionally, the plane containing the first position point, the second position point, and the third position point is the first plane;

[0028] Based on the magnitudes of A and B, determine the inclination direction of the plane containing each preset location point, including:

[0029] When A>0, the tilt direction of the first plane is determined to be tilting towards the side closer to the horizontal plane along the positive direction of the first direction;

[0030] When A < 0, the tilt direction of the first plane is determined to be tilting away from the horizontal plane along the positive direction of the first direction;

[0031] When B>0, the tilt direction of the first plane is determined to be tilting towards the side closer to the horizontal plane along the positive direction of the second direction;

[0032] When B < 0, the tilt direction of the first plane is determined to be tilting away from the horizontal plane along the positive direction of the second direction.

[0033] Optionally, the control adjustment module adjusts the position of the LDI lens according to the tilt angle and tilt direction, including:

[0034] Based on the tilt angle and tilt direction, the control adjustment module adjusts the tilt angle in the opposite direction of the tilt direction to adjust the position of the LDI lens.

[0035] Optionally, the preset angle error range is 0.005°-0.01°.

[0036] In this invention, the controller first drives the workpiece stage to move sequentially to multiple preset position points, and stabilizes at each point. A displacement sensor collects the height of the LDI lens relative to the workpiece stage at that point and uploads all height data along with the corresponding position coordinates to the controller. Based on this discrete point data, the controller reconstructs the reference plane corresponding to the optical axis of the current LDI lens using a preset algorithm, and further calculates the tilt angle and tilt direction of this plane relative to the ideal horizontal plane. Subsequently, the controller generates a lifting / lowering command for the adjustment module based on the determined tilt angle and tilt direction and sends it to the adjustment module. Upon receiving the adjustment command, the adjustment module performs micron- or even nanometer-level position adjustments, changing the local support height of the LDI lens to correct its overall spatial posture, and adjusts according to feedback until the tilt angle is within a preset angle error range. Using this structure, precise measurement and high-precision adjustment of the LDI lens's verticality are achieved, significantly improving the focusing consistency and image accuracy of laser direct-write imaging. The logic is simple, the cost is low, and the structure is simple.

[0037] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure of an LDI lens verticality adjustment system provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of another LDI lens verticality adjustment system provided in an embodiment of the present invention;

[0041] Figure 3 A flowchart of an LDI lens verticality adjustment method provided in an embodiment of the present invention;

[0042] Figure 4 A flowchart of another LDI lens verticality adjustment method provided in an embodiment of the present invention. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0045] In one embodiment, Figure 1 This is a schematic diagram of an LDI lens verticality adjustment system provided in an embodiment of the present invention. This embodiment is applicable to situations requiring rapid and accurate measurement of the verticality of an LDI lens, such as... Figure 1 As shown, the LDI lens verticality adjustment system includes an adjustment module 1, a controller 2, a lens receiving plate 3, a workpiece stage 7, and a displacement sensor 4. The lens receiving plate 3 and the adjustment module 1 are provided with alignment through holes 10, in which the LDI lens 5 is fixed. The displacement sensor 4 is located on the LDI lens 10. The controller 2 is electrically connected to the displacement sensor 4, the workpiece stage 7, and the adjustment module 1. The controller 2 controls the workpiece stage 7 to move between multiple preset position points. The displacement sensor 4 determines the height of the LDI lens 5 from the workpiece stage 7 when the workpiece stage 7 is at each preset position point. The controller 2 also receives the heights of multiple LDI lenses 5 and, based on each height, determines the tilt angle and tilt direction of the plane at each preset position point relative to the horizontal plane. Based on the tilt angle and tilt direction, the controller 2 controls the adjustment module 1 to adjust the position of the LDI lens 5 so that the tilt angle is within a preset angle error range.

[0046] The LDI (Laser Direct Imaging Lens) 5 is a high-precision imaging optical component used in laser direct-write lithography equipment. It is responsible for precisely focusing the laser beam onto the surface of the workpiece (such as a PCB board) to achieve micron-level pattern exposure. The perpendicularity of the LDI lens 5 (i.e., the vertical deviation of the optical axis from the horizontal plane) directly affects imaging accuracy and exposure consistency. Tilting can lead to focal plane shift and pattern distortion. The adjustment module 1 is a mechanical structural unit used to support and fine-tune the spatial attitude of the LDI lens 5. In this embodiment, the adjustment module 1 can be a precision screw, piezoelectric ceramic, magnetic levitation platform, etc., depending on the actual situation and is not limited here. The adjustment module 1 provides multi-degree-of-freedom fine-tuning capability, ensuring the LDI lens 5 is precisely corrected to a vertical state. The workpiece stage 7 is a moving platform that carries the workpiece to be processed (such as a PCB board) and can be precisely positioned in the XY plane. It is used to mount a reflective surface or reference surface as a reference target for the distance measurement of the LDI lens 5. Under the command of the controller 2, it moves sequentially to multiple preset measurement position points (usually more than 3 points, forming a measurement plane). The lens mounting plate 3 is used to fix the LDI lens 5. In this embodiment, the lens mounting plate 3 has through holes that align with the adjustment module 1, ensuring that the optical path of the LDI lens 5 is clear, facilitating vertical distance measurement, and fixing the LDI lens 5. The displacement sensor 4 is a non-contact distance measuring device (such as a laser displacement sensor, capacitive sensor, etc.), installed on the LDI lens 5 body or a nearby bracket, used to measure the distance (i.e., "height") from the bottom of the LDI lens 5 (or the optical axis reference point) to the surface of the workpiece stage 7 in real time when the workpiece stage 7 is stopped at each preset position point. In this embodiment, the reference... Figure 1 The displacement sensor 4 is located on one side of the LDI lens 5, and is fixed to the LDI lens 5 by the sensor fixing component 6. The controller 2 is the core control structure of this embodiment, used to control the coordinated operation between the workpiece stage 7, the adjustment module 1, and the displacement sensor 4.

[0047] Specifically, the controller 2 is electrically connected to the displacement sensor 4, the workpiece stage 7, and the adjustment module 1 respectively. The LDI lens 5 is fixed between the adjustment module 1 and the lens receiving plate 3 through the vertically aligned through holes 10. The displacement sensor 4 is installed on the body of the LDI lens 5 and can measure its vertical distance from the surface of the workpiece stage 7 in real time. After the system starts, the controller 2 first drives the workpiece stage 7 to move sequentially to multiple spatially distributed preset position points (usually three or four non-collinear points, such as the four corners of a rectangle or the three vertices of a triangle). These preset position points are all measurement position points. The controller 2 will stably stop at each preset position point when controlling the workpiece stage 7 to move to each position point. At this time, the displacement sensor 4 synchronously collects the height value of the LDI lens 5 relative to the workpiece stage 7 at that point and uploads all height data along with the corresponding position coordinates to the controller 2. Based on these discrete point data, controller 2 reconstructs the reference plane corresponding to each preset position point after the LDI lens 5 moves using the least squares method, plane fitting algorithm, or preset logic processing method. It further calculates the tilt angle and tilt direction of the plane at each preset position point relative to the horizontal plane (e.g., "front high, back low" or "left low, right high"). This tilt angle reflects the angle between the main axis of the LDI lens 5 and the horizontal plane. Figure 1 This can be represented by the workpiece stage 7 at the bottom. Subsequently, the controller 2, based on the determined tilt angle and tilt direction, and combined with the mechanical structural characteristics of the adjustment module 1 (such as the four-point support layout and actuator sensitivity), generates a lifting command for the adjustment module 1 and sends it to the adjustment module 1. After receiving the adjustment command, the adjustment module 1 performs micron- or even nanometer-level position adjustments, changing the local support height of the LDI lens 5, thereby correcting its overall spatial posture. After the adjustment is completed, the controller 2 automatically repeats the aforementioned multi-point measurement and fitting process to form a closed-loop verification. If the newly calculated tilt angle is within the preset angle error range (e.g., ±0.01°), the verticality correction is considered successful, and the system enters standby or exposure mode; if it does not meet the standard, the "measurement-analysis-adjustment" cycle continues iteratively until the accuracy requirements are met. This process not only achieves automated and highly repeatable calibration of the verticality of the LDI lens 5, but also significantly improves the focusing consistency and image accuracy of laser direct-write imaging. Compared to the traditional method of judging whether the lens is tilted by visually detecting and acquiring a chessboard pattern to determine whether there is defocus in the image at various points within the chessboard, this invention obtains the tilt angle and tilt direction of the LDI lens. The tilt angle and direction are clear, and the LDI lens can be calibrated with a single adjustment. Compared with visually detecting and acquiring images, it eliminates the need for multiple cycles of acquiring images, adjusting, acquiring images again, and adjusting again, making the process simpler and more time-saving and labor-saving.

[0048] In this invention, the controller first drives the workpiece stage to move sequentially to multiple preset position points, and stabilizes at each point. A displacement sensor collects the height of the LDI lens relative to the workpiece stage at that point and uploads all height data along with the corresponding position coordinates to the controller. Based on this discrete point data, the controller reconstructs the reference plane corresponding to the optical axis of the current LDI lens using a preset algorithm, and further calculates the tilt angle and tilt direction of this plane relative to the ideal horizontal plane. Subsequently, the controller generates a lifting / lowering command for the adjustment module based on the determined tilt angle and tilt direction and sends it to the adjustment module. Upon receiving the adjustment command, the adjustment module performs micron- or even nanometer-level position adjustments, changing the local support height of the LDI lens to correct its overall spatial posture, and adjusts according to feedback until the tilt angle is within a preset angle error range. Using this structure, precise measurement and high-precision adjustment of the LDI lens's verticality are achieved, significantly improving the focusing consistency and image accuracy of laser direct-write imaging. The logic is simple, the cost is low, and the structure is simple.

[0049] Optional, Figure 2 This is a schematic diagram of another LDI lens verticality adjustment system provided in an embodiment of the present invention, with reference to... Figure 2 As shown, the adjustment module 1 includes an adjustment pad 11 and four screws 12; each screw 12 is located at one of the four vertices of the adjustment pad 11. The adjustment pad 11 includes a through hole 10, in which the LDI lens 5 is fixed.

[0050] In one specific embodiment, the adjustment module 1 includes an adjustment pad 11 and four screws 12, each of which is a high-precision screw for fine-tuning. The adjustment pad 11 is a flat, highly stable metal base with a through hole 10 at its center that precisely matches the outer diameter of the LDI lens 5. This through hole 10 is used to securely and coaxially mount the LDI lens 10 within the through hole 10, ensuring structural stability and optical axis consistency during adjustment. The four screws 12 are respectively arranged at the four vertices of the adjustment pad 11 (i.e., the four corners of a rectangular or square layout). The lower end of each screw 12 is supported on the lens support plate 3, and the upper end is threadedly connected to the adjustment pad 11. By independently rotating any screw 12, the support height at that vertex can be slightly changed, thereby driving the adjustment pad 11 to produce a slight tilting movement around the X-axis and / or Y-axis. Since the LDI lens 5 is rigidly fixed in the through hole 10, the attitude change of the adjusting pad 11 is directly transmitted to the LDI lens 5, realizing two-dimensional (pitch and roll) precision adjustment of the verticality of the optical axis of the LDI lens 5. This structure has the advantages of mechanical simplicity, high rigidity, no hysteresis, and intuitive adjustment, and is particularly suitable for industrial scenarios with strict verticality requirements but no need for frequent dynamic adjustments. During operation, fine adjustment can be performed manually using a micro-head wrench, or semi-automatic or fully automatic calibration can be achieved through the controller 2 in conjunction with an electric micro-actuator. Combined with the feedback from the displacement sensor 4 and the calculation by the controller 2, the controller 2 will calculate the adjustment amount and direction of each screw 12 according to the tilt angle, and control each screw 12 to adjust accordingly, thereby changing the position of the LDI lens 5. The controller 2 determines whether the verticality of the LDI lens 5 is adjusted properly based on the tilt angle determined by the feedback adjustment. After determining that the tilt angle of the plane where each preset position point is located relative to the horizontal plane is controlled within the preset error range, it indicates that the adjustment is in place, realizing the verticality adjustment of the LDI lens 5, and ensuring the focusing accuracy and process consistency of laser direct writing imaging.

[0051] Based on the same inventive concept Figure 3 A flowchart of an LDI lens verticality adjustment method provided in an embodiment of the present invention is shown below. Figure 3 As shown, the method includes:

[0052] S110. Control the workpiece stage to move between multiple preset position points;

[0053] S120: Receive the height of multiple LDI lenses from the workpiece stage as determined by the displacement sensor when the workpiece stage is at each preset position point.

[0054] S130. Based on the height of each LDI lens, determine the tilt angle and tilt direction of the plane where each preset position point is located relative to the horizontal plane.

[0055] S140. Based on the tilt angle and tilt direction, the control adjustment module adjusts the position of the LDI lens so that the tilt angle is within the preset angle error range.

[0056] Specifically, when adjusting the verticality of the LDI lens, the workpiece stage is first moved sequentially to multiple spatially distributed preset positions (usually three or four non-collinear points, such as the four corners of a rectangle or the three vertices of a triangle). These preset positions are all measurement points. As the workpiece stage moves to each preset position, the displacement sensor simultaneously collects the height value of the LDI lens relative to the workpiece stage at that point and uploads all height data along with the corresponding position coordinates. Based on these discrete height data, the reference plane corresponding to the current LDI lens after moving to each preset position is reconstructed using the least squares method, plane fitting algorithm, or preset logic processing method. The tilt angle and tilt direction of this plane relative to the ideal horizontal plane are further calculated (e.g., "front high, back low" or "left low, right high"). Subsequently, based on the determined tilt angle and tilt direction, combined with the mechanical structural characteristics of the adjustment module (e.g., four-point support layout and actuator sensitivity), a lifting / lowering command is generated and sent to the adjustment module. After receiving the adjustment command, the adjustment module performs micron- or even nanometer-level position adjustments, changing the local support height of the LDI lens, thereby correcting its overall spatial orientation. After adjustment, the aforementioned multi-point measurement and fitting process is automatically repeated to form a closed-loop verification. If the newly calculated tilt angle is within the preset angle error range (e.g., ±0.01°), the verticality correction is considered successful, and the system enters standby or exposure mode; if it does not meet the standard, the "measurement-analysis-adjustment" cycle continues iteratively until the accuracy requirements are met. This process not only achieves automated and highly repeatable calibration of LDI lens verticality but also significantly improves the focus consistency and image accuracy of laser direct-write imaging.

[0057] The staged approach of this invention involves controlling the workpiece stage to move between multiple preset position points; receiving the heights of multiple LDI lenses from the workpiece stage as determined by displacement sensors when the workpiece stage is at each preset position point; determining the tilt angle and tilt direction of the plane at each preset position point relative to the horizontal plane based on the height of each LDI lens; and adjusting the position of the LDI lenses using an adjustment module based on the tilt angle and tilt direction to ensure that the tilt angle is within a preset angle error range. Using this method, precise measurement and high-precision adjustment of the LDI lens verticality are achieved, significantly improving the focusing consistency and image accuracy of laser direct-write imaging.

[0058] In another specific embodiment, optionally, Figure 4This is a flowchart of another LDI lens verticality adjustment method provided by an embodiment of the present invention. This embodiment refines the specific implementation of S130 in the above embodiment, which involves determining the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane based on the height of each LDI lens, as follows:

[0059] Determine the spatial coordinates of each preset position point based on the height of each LDI lens;

[0060] Based on the spatial coordinates, determine the normal vector of the plane containing each preset location point;

[0061] Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane.

[0062] Furthermore, the specific implementation of S140 in the above embodiment, which controls the adjustment module to adjust the position of the LDI lens according to the tilt angle and tilt direction, is refined as follows:

[0063] Based on the tilt angle and tilt direction, the control adjustment module adjusts the tilt angle in the opposite direction of the tilt direction to adjust the position of the LDI lens.

[0064] For details not covered in this embodiment, please refer to the above embodiments, which will not be repeated here.

[0065] refer to Figure 4 As shown, the method includes:

[0066] S210, Control the workpiece stage to move between multiple preset position points.

[0067] S220: Receives the height of multiple LDI lenses from the workpiece stage as determined by the displacement sensor when the workpiece stage is at each preset position.

[0068] The preset position points include a first position point, a second position point, and a third position point; the plane containing the first position point, the second position point, and the third position point is the first plane, and the normal vector of the first plane is the first normal vector.

[0069] S230. Determine the spatial coordinates of each preset position point based on the height of each LDI lens.

[0070] Among them, the spatial coordinates of each preset location point are the three-dimensional coordinates of each location point.

[0071] Specifically, when determining the spatial coordinates of each LDI lens based on its height at a preset position point, the two-dimensional coordinates (X, Y) of each preset position point in the horizontal plane are first obtained. These coordinates are determined by pre-set layout rules or the nominal position in the motion control system and remain fixed. Then, at each preset position point, the vertical height Z of the LDI lens relative to the same reference horizontal plane is obtained by measuring the height; this height is the Z-coordinate of that preset position point. The measured height value is then directly used as the third dimension of the spatial coordinates and combined with the known X and Y coordinates to form a complete three-dimensional spatial coordinate (X, Y, Z). For example, at preset position point P1, its planar position is X=50mm, Y=80mm, and the measured LDI lens height is Z=295.3mm; therefore, the spatial coordinates of this point are determined as (50.0, 80.0, 295.3). Similarly, by processing all preset position points sequentially, the set of three-dimensional coordinates of each point based on the actual height measurement can be obtained. The entire process uses a unified coordinate system as a reference to ensure the consistency and comparability of all spatial coordinates, thereby achieving accurate determination of the spatial coordinates of each preset position point based solely on the LDI lens height information. For example, the spatial coordinates of three preset position points are determined as follows: , , ,in, The spatial coordinates of the first position point, The spatial coordinates of the second position point. These are the spatial coordinates of the third location point.

[0072] S240. Determine the normal vector of the plane containing each preset location point based on the spatial coordinates.

[0073] This step can be further refined as follows: Based on the spatial coordinates and the first calculation formula, determine the normal vector of the plane containing each preset location point; the first calculation formula is: ,in, Let A be the first normal vector, B be the position of the first normal vector in the first direction, C be the position of the first normal vector in the second direction, and C be the position of the first normal vector in the third direction. The first direction, the second direction, and the third direction are all perpendicular to each other. , , , The spatial coordinates of the first position point, The spatial coordinates of the second position point. These are the spatial coordinates of the third location point.

[0074] Specifically, after determining the spatial coordinates of the first, second, and third position points, the normal vector of the plane containing each preset position point is determined based on the spatial coordinates of the three position points. This is the normal vector of the spatial plane (the first plane) fitted by the three coordinate values ​​(the first normal vector). This can be calculated using the first formula. ,in, Let A be the first normal vector, B be the position of the first normal vector in the first direction, and C be the position of the first normal vector in the third direction. The first, second, and third directions are mutually perpendicular, meaning they can be one of the x-axis, y-axis, and z-axis directions, respectively. In this embodiment, the first direction is the positive x-axis direction, the second direction is the positive y-axis direction, and the third direction is the positive z-axis direction. Furthermore, A, B, and C can be calculated using formulas, where... Therefore, after determining the spatial coordinates of the first, second, and third position points, substituting the corresponding parameters into the formula for calculating A yields the value of A. Similarly, , By substituting the corresponding parameters from the spatial coordinates of the first, second, and third position points into the calculation formulas for B and C, the values ​​of B and C can be obtained respectively. After A, B, and C are determined, the first normal vector of the first plane... Then it can be determined.

[0075] S250. Based on the normal vector of the plane where each preset position point is located and the normal vector of the horizontal plane, determine the tilt angle and tilt direction of the plane where each preset position point is located relative to the horizontal plane.

[0076] This step can be further refined as follows: Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, and using the second calculation formula, determine the tilt angle of the plane containing each preset position point relative to the horizontal plane; the second calculation formula is: ,in, The tilt angle is determined by the spatial coordinates, which determine the tilt direction of the plane containing each preset position point.

[0077] Specifically, determine the first normal vector. Then, based on the first normal vector By using the normal vector to the horizontal plane and the second calculation formula, the tilt angle and tilt direction of the first plane relative to the horizontal plane can be determined. In this embodiment, The normal vector of the horizontal plane According to the formula for calculating the angle between two planes, By substituting A, B, and C into the above formula, the tilt angle of the first plane relative to the horizontal plane can be calculated. Then, based on the first normal vector... This allows us to determine the tilt direction of the plane (first plane) where each preset position point is located.

[0078] Furthermore, the derivation of the second calculation formula will be briefly explained here. The normal vector of the first plane... The normal vector of the horizontal plane According to the formula The tilt angle can be obtained by calculating using inverse trigonometric functions. .

[0079] S260. Based on the tilt angle and tilt direction, the control adjustment module adjusts the tilt angle in the opposite direction of the tilt direction to adjust the position of the LDI lens so that the tilt angle is within the preset angle error range.

[0080] Optionally, the preset angle error range is 0.005°-0.01°.

[0081] Specifically, after determining the tilt angle and tilt direction, the control adjustment module adjusts the position of the LDI lens according to the tilt angle and tilt direction. The control adjustment module adjusts the tilt angle in the opposite direction of the tilt direction to correct the verticality of the LDI lens. The tilt angle is calculated through feedback until it falls within a preset angle error range. In this embodiment, the preset angle error range is 0.005°-0.01°. That is, when the calculated tilt angle is within 0.005°-0.01°, it indicates that the LDI lens is properly adjusted, achieving precise adjustment of the LDI lens's verticality. For example, after obtaining the tilt angle α and its tilt direction, the target compensation angle is converted into the required vertical displacement of each adjustment point based on the mechanical layout of the adjustment module (e.g., the coordinates of the four screw vertices). For instance, if it is detected that the LDI lens is too low along the positive x-axis (manifested as a negative pitch angle), the adjustment unit in the positive x-axis direction (e.g., the two front screws) is instructed to be slightly adjusted upwards, or the unit in the negative x-axis direction is slightly adjusted downwards, thereby applying a compensation tilt in the opposite direction to the LDI lens. This adjustment indirectly achieves closed-loop correction of the optical axis attitude by precisely controlling the height difference of the support points until the actual tilt angle falls within the preset angle error range.

[0082] The technical solution of this invention involves determining the spatial coordinates of each preset position point based on the height of each LDI lens; determining the normal vector of the plane containing each preset position point based on the spatial coordinates; determining the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane; and adjusting the tilt angle by controlling the adjustment module in the opposite direction of the tilt direction based on the tilt angle and tilt direction, thereby adjusting the position of the LDI lens. Using this method, precise determination of the tilt angle and tilt direction is achieved, thus enabling precise adjustment of the verticality of the LDI lens.

[0083] In another specific embodiment, optionally, the tilt direction of the plane where each preset position point is located is determined according to the spatial coordinates, including: determining the tilt direction of the plane where each preset position point is located according to the magnitudes of A and B.

[0084] This step can be further refined as follows: when A>0, the tilt direction of the first plane is determined to be tilted towards the side closer to the horizontal plane along the positive direction of the first direction; when A<0, the tilt direction of the first plane is determined to be tilted away from the horizontal plane along the positive direction of the first direction; when B>0, the tilt direction of the first plane is determined to be tilted towards the side closer to the horizontal plane along the positive direction of the second direction; when B<0, the tilt direction of the first plane is determined to be tilted away from the horizontal plane along the positive direction of the second direction.

[0085] Specifically, in this embodiment, by fitting the height data of multiple preset position points, a spatial equation describing the LDI lens reference plane is established, which can typically be expressed as: Ax + By + Cz + D = 0, where x and y are the coordinates of each preset measurement point in the horizontal plane, z is the height of the LDI lens above the horizontal plane at the corresponding point, defined using a right-hand rectangular coordinate system. The X-axis and Y-axis lie in the horizontal reference plane, representing the front-back and left-right directions, respectively. That is, coefficients A and B respectively characterize the tilt gradient of the first plane in the first direction (e.g., the X-axis, representing the front-back direction) and the second direction (e.g., the Y-axis, representing the left-right direction). The Z-axis is vertically upward, and a larger Z value indicates that the LDI lens is higher in space at that position (i.e., farther from the horizontal plane). After A, B, and C are determined, the spatial coordinates of one of the preset position points are substituted into the above formula to calculate the value of D, thus determining the spatial equation. Based on this, the tilt direction of the first plane can be determined based on the values ​​of A and B. Specifically, the first normal vector of the first plane is... Its direction is perpendicular to the first plane and points to the side determined by the signs of the coefficients. Under normal measurement conditions, since all sampling points are located above the horizontal plane and the plane as a whole faces upward, the Z component of the fitted normal vector satisfies C>0, that is, the normal vector generally points upward.

[0086] Under these conditions, the sign of the coefficient A directly reflects the tilting trend of the plane in the X direction: When A > 0, the component of the first normal vector in the X-axis direction is positive, meaning the normal vector deflects forward (in the positive X-axis direction). According to the right-hand rule and the perpendicular relationship between the plane and the normal vector, the plane itself must "tilt downward" in the positive X-axis direction, that is, along the positive X-axis direction, the plane gradually approaches the horizontal plane (its height decreases), meaning the tilting direction is along the positive first direction towards the side closer to the horizontal plane. Conversely, if A < 0, the projection of the normal vector in the X-axis direction is negative, meaning it deflects in the negative X-axis direction. At this time, the plane "tilts upward" in the positive X-axis direction, meaning the LDI lens is higher and farther from the horizontal plane in the positive X-axis direction, meaning the tilting direction is along the positive first direction towards the side farther from the horizontal plane. Similarly, when B > 0, the first normal vector has a positive component in the positive Y-axis direction, indicating that the normal vector deflects to the right (positive Y-axis direction). Therefore, the plane itself tilts downwards along the positive Y-axis direction, and the camera position is lower on the positive Y-axis side. That is, the tilt direction of the first plane is along the positive second direction towards the side closer to the horizontal plane. When B < 0, the normal vector deflects in the negative Y-axis direction, and the plane tilts upwards along the positive Y-axis direction. The camera position is higher on the positive Y-axis side. That is, the tilt direction of the first plane is along the positive second direction towards the side farther from the horizontal plane.

[0087] This judgment logic does not require converting the equation into an explicit height function. Instead, it directly derives the correspondence between the tilt direction and the sign of the coefficients based on the spatial orientation relationship between the coefficients and the normal vector in the general formula. Combined with the standard right-hand coordinate system and the physical constraint of C>0, it ensures that the control system can accurately identify the low and high sides of the LDI lens plane, providing reliable directional guidance for the subsequent adjustment module and ensuring the directional correctness and accuracy reliability of the verticality correction process.

[0088] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0089] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An LDI lens verticality adjustment system, characterized in that, The device includes an adjustment module, a controller, a lens receiving plate, a workpiece stage, and a displacement sensor. The lens receiving plate and the adjustment module are provided with alignment through holes. The LDI lens is fixed in the through holes. The displacement sensor is located on the LDI lens. The controller is electrically connected to the displacement sensor, the workpiece stage, and the adjustment module, respectively. The controller is used to control the movement of the workpiece stage between multiple preset position points; The displacement sensor is used to determine the height of the LDI lens from the workpiece stage when the workpiece stage is at each of the preset position points; The controller is also configured to receive the heights of the multiple LDI lenses, and determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane based on each height; and control the adjustment module to adjust the position of the LDI lens based on the tilt angle and the tilt direction so that the tilt angle is within a preset angle error range.

2. The LDI lens verticality adjustment system according to claim 1, characterized in that, The adjustment module includes an adjustment pad and four screws; each screw is located at one of the four vertices of the adjustment pad, and the adjustment pad includes a through hole, in which the LDI lens is fixed.

3. A method for adjusting the verticality of an LDI lens, characterized in that, include: Control the workpiece stage to move between multiple preset positions; The distance between the multiple LDI lenses and the workpiece stage is determined by the displacement sensor when the workpiece stage is at each of the preset position points; Based on the height of each LDI lens, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane; Based on the tilt angle and the tilt direction, the control adjustment module adjusts the position of the LDI lens so that the tilt angle is within a preset angle error range.

4. The LDI lens verticality adjustment method according to claim 3, characterized in that, Based on the height of each LDI lens, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane, including: The spatial coordinates of each preset position point are determined based on the height of each LDI lens. Based on the spatial coordinates, determine the normal vector of the plane containing each of the preset position points; Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane.

5. The LDI lens verticality adjustment method according to claim 4, characterized in that, The preset position points include a first position point, a second position point, and a third position point; the plane in which the first position point, the second position point, and the third position point are located is a first plane, and the normal vector of the first plane is a first normal vector; Based on the spatial coordinates, determine the normal vector of the plane containing each preset position point, including: Based on the spatial coordinates, and using the first calculation formula, determine the normal vector of the plane containing each of the preset position points; The first calculation formula is: ,in, Let A be the first normal vector, B be the position of the first normal vector in the first direction, C be the position of the first normal vector in the second direction, and C be the position of the first normal vector in the third direction. The first direction, the second direction, and the third direction are perpendicular to each other. , , , Let these be the spatial coordinates of the first position point. The spatial coordinates of the second position point are: The spatial coordinates of the third location point are given.

6. The LDI lens verticality adjustment method according to claim 5, characterized in that, Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, determine the tilt angle and tilt direction of the plane containing each preset position point relative to the horizontal plane, including: Based on the normal vector of the plane containing each preset position point and the normal vector of the horizontal plane, the tilt angle of the plane containing each preset position point relative to the horizontal plane is determined using a second calculation formula; the second calculation formula is: ,in, The tilt angle is mentioned. Based on the spatial coordinates, determine the tilt direction of the plane containing each of the preset position points.

7. The LDI lens verticality adjustment method according to claim 6, characterized in that, Based on the spatial coordinates, the tilt direction of the plane containing each of the preset position points is determined, including: Based on the magnitudes of A and B, determine the inclination direction of the plane containing each of the preset position points.

8. The LDI lens verticality adjustment method according to claim 7, characterized in that, The plane containing the first position point, the second position point, and the third position point is the first plane; Based on the magnitudes of A and B, determine the inclination direction of the plane containing each of the preset position points, including: When A>0, the tilt direction of the first plane is determined to be tilting towards the side closer to the horizontal plane along the positive direction of the first direction; When A < 0, the tilt direction of the first plane is determined to be tilting away from the horizontal plane along the positive direction of the first direction; When B>0, the tilt direction of the first plane is determined to be tilting towards the side closer to the horizontal plane along the positive direction of the second direction; When B < 0, the tilt direction of the first plane is determined to be tilted away from the horizontal plane along the positive direction of the second direction.

9. The LDI lens verticality adjustment method according to claim 3, characterized in that, Based on the tilt angle and the tilt direction, the control adjustment module adjusts the position of the LDI lens, including: Based on the tilt angle and the tilt direction, the adjustment module is controlled to adjust the tilt angle in the opposite direction of the tilt direction to adjust the position of the LDI lens.

10. The LDI lens verticality adjustment method according to claim 3, characterized in that, The preset angle error range is 0.005°-0.01°.

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