Lower knife distance acquisition method, medium and equipment for large-scale microlens array processing

Abstract

This invention relates to the field of ultra-precision machining technology, and particularly to a method, medium, and equipment for obtaining the tool entry distance in the machining of large-scale microlens arrays. The method targets the tool positioning point within the aspherical surface region of the microlens unit. It discretizes the tool tip arc into spatial points and maps them to the workpiece coordinate system. The normal vector of each discrete point on the workpiece surface is obtained through the aspherical analytical expression. The absolute value of the inner product between the tool's discrete tangent vector and the workpiece normal vector is calculated, and the point with the minimum value is selected as the true contact point. Based on the Z-coordinate difference of this point, the Z-axis compensation is calculated as the tool entry distance. This method overcomes the limitations of traditional empirical compensation by dynamically reflecting the local contact relationship between the tool and the aspherical surface through the inner product criterion, avoiding systematic errors. Because the radius of the tool tip arc is smaller than the minimum radius of curvature of the microlens, it ensures that the contact point is a unique tangent point, effectively preventing overcutting of concave surfaces or high-curvature regions, and achieving high-precision machining.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision machining technology, and in particular to a method, medium, and equipment for obtaining the cutting distance in the machining of large-scale microlens arrays. Background Technology

[0002] As optical systems evolve towards lightweight, integrated, and high-performance designs, optical microstructures with complex micro / nano topologies are widely used in aerospace, optoelectronic communications, laser projection, AR / VR, and high-end weaponry due to their superior light field manipulation capabilities. Large-scale microlens arrays, as a typical example, require sub-micron level surface accuracy (PV < 0.1 μm) and surface roughness better than 2 nm, which traditional fabrication methods struggle to meet.

[0003] Among numerous manufacturing technologies, single-point diamond planing technology based on Fast Tool Servo (FTS) is considered a core means of achieving efficient and ultra-precision creation of optical microstructure surfaces due to its high dynamic response and nanometer-level positioning accuracy. During the machining process, in order to ensure machining quality and shorten the cycle time, FTS is often used to control the Z-axis displacement of the tool in real time to achieve accurate reproduction of aspherical contours.

[0004] However, since the tip radius of diamond tools is typically in the range of tens to hundreds of micrometers, which is on the order of the curvature radius of a microlens unit, improper control of the depth of cut can easily lead to overcutting between the tool and the workpiece. Figure 3 As shown, this causes surface deformation. Therefore, it is necessary to accurately calculate the cutting distance at each cutting point to ensure that the tool tip arc is in tangential contact with the workpiece surface, thereby compensating for the deformation caused by the tool geometry.

[0005] Existing methods often employ empirical compensation or global geometric approximation, resulting in insufficient accuracy. Furthermore, when machining arrays of millions of data points, calculating compensation values ​​for each tool position in real time would lead to machine tool controller memory overflow and computational delays, severely impacting machining efficiency and stability. In addition, traditional table lookup methods suffer from high data redundancy, with file sizes often reaching GB levels, failing to meet real-time loading requirements.

[0006] Therefore, there is an urgent need for a method to obtain the cutting distance that can both ensure nanometer-level contact accuracy and overcome data bottlenecks, so as to achieve efficient, stable, and high-precision ultra-precision machining of large-scale microlens arrays. Summary of the Invention

[0007] To address one of the aforementioned technical problems, the present invention adopts the following technical solution:

[0008] According to one aspect of the present invention, a method for obtaining the tool entry distance for large-scale microlens array fabrication is provided, the method comprising the following steps:

[0009] For each tool positioning point within the aspherical surface region of the microlens unit, the tool tip arc is discretized into multiple spatial points and mapped to the workpiece coordinate system; the microlens unit is any microlens unit in a large-scale microlens array;

[0010] Obtain the XY coordinates of each mapped tool discrete point, substitute them into the aspherical analytical expression of the microlens unit surface shape, and obtain the normal vector of the workpiece surface point corresponding to each mapped tool discrete point;

[0011] Calculate the absolute value of the inner product of the tangent vector at each discrete point of the tool and the normal vector of the corresponding workpiece surface point, and select the discrete point of the tool with the smallest absolute value of the inner product as the actual contact point.

[0012] Based on the difference between the Z-coordinate of the actual contact point in the current tool lifting state and the Z-coordinate of the corresponding workpiece surface point, the Z-axis compensation amount is calculated and used as the tool positioning point's down-cut distance.

[0013] According to a second aspect of the present invention, a non-transitory computer-readable storage medium is provided, which stores a computer program that, when executed by a processor, implements the above-described method for obtaining the cutting distance for large-scale microlens array processing.

[0014] According to a third aspect of the present invention, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for obtaining the cutting distance for large-scale microlens array processing.

[0015] This invention has at least one of the following beneficial effects:

[0016] This invention overcomes the limitations of traditional empirical compensation or geometric approximation methods by using a method that "determines the true contact point based on the criterion of minimum absolute value of the inner product." At each tool positioning point, the inner product of the tool's discrete point tangent vector and the workpiece surface normal vector is calculated, and the point with the smallest absolute value of the inner product (close to 0) is selected as the true contact point. The Z-axis compensation is then calculated based on the Z-coordinate difference of this point. This method dynamically and accurately reflects the local contact relationship between the tool and the aspherical surface, avoiding systematic errors caused by global tool lifting height or fixed compensation values.

[0017] Because the tip radius of a diamond tool is on the same order of magnitude as the radius of curvature of a microlens, traditional methods are prone to overcutting on concave surfaces or in areas of high curvature. This invention uses the minimum absolute value of the inner product criterion to ensure that the selected contact point is the only contact point between the tool and the workpiece. Since the tool tip radius is required to be smaller than the minimum radius of curvature of the microlens during tool selection, the remaining tool portion is positioned above the workpiece surface, thus achieving "tangential contact" rather than "embedded contact."

[0018] Simultaneously, under ideal tangency conditions, only one discrete point of the tool has a dot product between its tangent vector and the workpiece normal vector that reaches a global minimum (most negative), while the dot products at all other points are significantly greater than this value. If the dot products at multiple points are close to the minimum, it indicates that multiple positions on the tool edge are simultaneously "pressing" against the workpiece surface, suggesting excessive local curvature or an insufficiently small tool, posing a risk of multi-point contact or interference. This method implicitly incorporates a local curvature matching verification mechanism: if the dot product at a certain point significantly deviates from the minimum value, it indicates an interference risk, and the system can provide early warning or adjust the path. Therefore, this invention fundamentally eliminates overcutting and surface damage, improving the robustness and safety of the machining process. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a flowchart of a method for obtaining the cutting distance in large-scale microlens array processing, provided by an embodiment of the present invention.

[0021] Figure 2 is a geometric schematic diagram of the discretization of the blade tip arc provided in an embodiment of the present invention;

[0022] Figure 3 is a geometrical schematic diagram of the interference-compensation calculation provided in an embodiment of the present invention;

[0023] Figure 4 is a partial cutting distance data diagram of the target two-dimensional compensation depth matrix provided in an embodiment of the present invention;

[0024] Figure 5 is a surface plotting diagram based on the tool positioning point in the target two-dimensional compensation depth matrix and the corresponding tool drop distance. The vertical axis of each line represents the tool drop distance △Z of each acquisition point on the corresponding planing path. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0026] As one possible embodiment of the present invention, such as Figure 1As shown, a method for obtaining the tool entry distance in the fabrication of large-scale microlens arrays is provided, the method comprising the following steps:

[0027] S100: For each tool positioning point within the aspherical surface region of the microlens unit, the tool tip arc is discretized into multiple spatial points and mapped to the workpiece coordinate system. The microlens unit is any microlens unit in a large-scale microlens array.

[0028] A microlens unit is any basic periodic unit in a large-scale microlens array. The unit region corresponding to a single microlens unit includes the projection area of ​​the aspherical surface onto the XY plane (i.e., the effective machining area) and the unit gap area (the non-machinable base area). For the aspherical surface region of the microlens unit, k planing paths (such as concentric circle trajectories or radial straight lines) are planned to cover the effective machining area. Each path uniformly samples L points, forming a two-dimensional tool positioning point set {Qj} (j=1,2,...,k×L). Each tool positioning point contains XY coordinates (xj,yj), representing the theoretical position of the tool tip arc center in the XY plane. Path planning must ensure coverage of the entire aspherical projection area. The sampling density is set according to the surface accuracy requirements, with a typical sampling interval of 1-5μm to balance machining efficiency and surface fitting error.

[0029] S100 includes the following sub-steps:

[0030] S110: In the tool coordinate system, the tool tip arc is uniformly discretized into N spatial points, forming a tool discrete point set.

[0031] Specifically, such as Figure 2 As shown, the specific implementation steps of S110 are illustrated in the following example:

[0032] Based on the tool design and machining requirements, the following basic parameters are defined:

[0033] For example: tool tip radius: Rt=100μm; rake angle: γ0=0°; maximum depth of cut: h=6μm (verification condition: because 6 μm is much larger than the maximum sagitta of the machined surface 2.1299 μm, thus ensuring that all possible contact points of the tool tip radius are included in the calculation).

[0034] Calculate the range of the tool tip radius and the angle of entry.

[0035] The radius of the cutting tip corresponding to the maximum depth of cut:

[0036] Based on geometric relationships, the arc angle corresponding to the depth of tangency h can be calculated using the law of cosines: ;

[0037] Calculation of the angle of entry boundary:

[0038] Determine the range of discrete angles for the circular arc based on the tool entry direction and the cutting parameter d_cut_in:

[0039] Maximum angle of entry:

[0040] ;

[0041] Minimum angle of entry:

[0042] ;

[0043] Determine discretization sampling parameters

[0044] To achieve dense discretization of circular arcs, a sampling strategy with equal angular step sizes is set:

[0045] Number of sampling points: Nt=300 (300 discrete points including the start and end points);

[0046] Angle step size:

[0047] Based on the angle range [θ] t-min ,θ t-max ] Calculate the angular interval between adjacent sampling points:

[0048] ;

[0049] The above steps complete the parameter definition, angle range calculation, and sampling strategy setting before tool discretization, laying the foundation for subsequent discrete point coordinates and tangent vector solving.

[0050] In the local coordinate system of the tool, let the radius of the tool tip arc be Rt, then any sampling point on it can be represented as:

[0051] ;

[0052] i = 1, 2, ..., N, where N is set according to accuracy requirements (preferably N ≥ 50), such as N = Nt = 300. The discrete points are evenly distributed along the tool tip arc to ensure sufficient sampling of the tool edge shape.

[0053] S120: Calculate the three-dimensional coordinates of each discrete point in the tool coordinate system and its tangent vector.

[0054] Corresponding points The tangent vector is obtained from the parametric derivative: After normalization, the unit tangent vector is obtained. , used for subsequent inner product calculations.

[0055] S130: Set the preset tool lifting height and position the center of the tool arc to the XY position of the current tool positioning point.

[0056] Let the current projection position of the tool on the workpiece surface be (x0, y0), and the tool lifting height be h. lift (Usually slightly greater than the maximum depth of cut), then the initial Z-coordinate of the tool arc center in the workpiece coordinate system is: z c =h lift .

[0057] S140: The tool discrete point set is rigidly transformed to the workpiece coordinate system through a homogeneous transformation matrix.

[0058] By using a homogeneous transformation matrix that includes rotation angles and translation terms, all discrete points and their corresponding tangent vectors are rigidly transformed to the workpiece coordinate system, completely preserving the spatial attitude information of the tool and providing a geometric basis for subsequent contact point identification. Traditional methods often simplify the tool to a single tangent point or use fixed offset compensation, ignoring the influence of tool tip curvature. This step, through high-density discretization and rigid body transformation, achieves accurate reconstruction of the tool's three-dimensional geometry in workpiece space, laying the foundation for subsequent real contact point identification and serving as a prerequisite for achieving nanometer-level compensation accuracy.

[0059] S200: Obtain the XY coordinates of each mapped tool discrete point, substitute them into the aspherical analytical expression of the microlens unit surface shape, and obtain the normal vector of the workpiece surface point corresponding to each mapped tool discrete point.

[0060] The surface shape of microlenses is typically described using aspherical polynomials, for example:

[0061] ;

[0062] in, Where 𝑐 is the vertex curvature, 𝑘 is the conic coefficient, and 𝐴 is the conicity coefficient. 𝑛 These are the coefficients of higher-order terms.

[0063] S200 includes the following sub-steps:

[0064] S210: Applying the chain rule to equations for aspherical surfaces Find the derivative and calculate the partial derivative at the XY coordinates. and .

[0065] Take the discretized points of the tool after mapping Substitute the XY coordinates into the above aspherical equation to calculate the partial derivatives at those XY coordinates.

[0066] S220: Based on and Construct the gradient vector After normalization, the unit normal vector n is obtained.

[0067] S300: Calculate the absolute value of the inner product of the tangent vector of each tool discrete point and the normal vector of the corresponding workpiece surface point, and select the tool discrete point with the smallest absolute value of the inner product as the actual contact point.

[0068] For each discrete point i, calculate the absolute value of the inner product: ;

[0069] Select to make dot i The smallest (i.e., closest to 0) point i * As a real point of contact: .

[0070] As the cutting tool approaches the workpiece in a fixed posture, the ideal contact state is when a point on the tool tip arc is tangent to the workpiece surface. At this point, the tangent vector at that point is orthogonal to the normal vector of the workpiece surface, meaning the inner product is zero. However, since the tool tip arc has been discretized into a finite number of spatial points, the actual tangent point may not fall exactly on any of these discrete points. The smaller the absolute value of the inner product, the closer the point is to the "tangent" state, thus effectively avoiding positioning errors caused by discretization. When dot i When the value is closest to 0, it indicates that the direction of motion at that point is closest to being orthogonal to the surface, best conforming to the geometric definition of "tangent". Even if the discretization error cannot be exactly zero, this method can still approximate the actual contact position with high accuracy.

[0071] S400: Based on the difference between the Z coordinate of the actual contact point in the current tool lifting state and the Z coordinate of the corresponding workpiece surface point, calculate the Z-axis compensation amount, which is used as the tool positioning point's down-tool distance.

[0072] S400 includes the following sub-steps:

[0073] S410: Obtain the Z-coordinate of the actual contact point in the attitude after rigid body transformation. tool contact .

[0074] S420: Obtain the Z-coordinate of the workpiece surface point corresponding to the actual contact point. work contact .

[0075] S430: Calculate the tool drop distance ΔZ=z tool contact -z work contact This ensures that the tool tip arc is tangent to the workpiece surface, avoiding overcutting.

[0076] like Figure 3 As shown, this compensation strategy ensures that the tool cuts into the workpiece in a "tangential" manner rather than "embeds" into it, fundamentally avoiding surface damage caused by tool geometric interference and ensuring the integrity and smoothness of the optical surface.

[0077] After calculating the cutting distance for a single microlens unit, the method also includes the following sub-steps:

[0078] S510: Arrange the tool positioning distances of all tool positioning points in the projection area of ​​the aspherical surface in the XY plane according to their XY positions to generate an initial two-dimensional compensation depth matrix.

[0079] S520: Based on the initial two-dimensional compensation depth matrix, the tool drop distance corresponding to all tool positioning points in the unit gap area is set to 0 to generate the target two-dimensional compensation depth matrix.

[0080] The initial two-dimensional compensation depth matrix only records the tool entry distance of each tool positioning point distributed in the effective machining area. It is necessary to extend the initial two-dimensional compensation depth matrix to the entire cycle unit region P. x ×P y And assign ΔZ=0 to all positions in the element gap region to obtain the target two-dimensional compensation depth matrix, some of which is as follows: Figure 4 As shown, this explicitly distinguishes between the machining area and the non-machining area, preventing accidental tool entry. The planing trajectory corresponding to the tool entry distance at each tool positioning point, obtained from the target two-dimensional compensation depth matrix, is as follows: Figure 5 As shown.

[0081] S530: Based on the target two-dimensional compensation depth matrix, obtain the tool positioning distance corresponding to each tool positioning point in other microlens units in the large-scale microlens array.

[0082] S530 includes the following sub-steps:

[0083] S531: Real-time acquisition of the global coordinates (x) of the current tool positioning point global ,y global ).

[0084] S532: Based on the X-axis period length P of the microlens unit x and Y-axis period length P y The local relative coordinate x is calculated through modular arithmetic. local and y local x local and y local The following conditions must be met:

[0085] x local =x global mod P x y local =y global mod P y .

[0086] Modulo operation is the core mathematical mechanism for achieving efficient reuse of periodic structures. Large-scale microlens arrays typically exhibit highly repetitive spatial arrangement characteristics, meaning that each microlens unit operates at a fixed period P in both the X and Y directions. x and P y The microlens units are arranged periodically. Therefore, the geometry and processing compensation behavior of all microlens units are completely consistent in the local coordinate system corresponding to the target two-dimensional compensation depth matrix.

[0087] For example: If P x =1.0 mm, P y =1.0 mm, the global coordinates (2.3 mm, 3.7 mm) are mapped to local coordinates (0.3 mm, 0.7 mm) after modulo operation, which are completely equivalent to the corresponding positions in the corresponding cells of the target two-dimensional compensation depth matrix. Therefore, only the compensation depth matrix of one microlens cell needs to be pre-calculated, and real-time cutting commands can be provided to any cell in the array by looking up a table.

[0088] S533: On the target's two-dimensional compensation depth matrix and its corresponding X / Y coordinate vectors, according to (x local ,y local Perform coordinate matching and data query to obtain the corresponding tool drop distance ΔZ.

[0089] S533 includes the following sub-steps:

[0090] S5331: If (x local ,y local If the surface falls into the projection area of ​​the aspherical surface, a non-zero compensation value ΔZ is obtained through bilinear interpolation or nearest neighbor interpolation, which controls the rapid tool servo system to move the tool.

[0091] S5332: If (x local ,y local If the tool falls into the unit gap area, the compensation value ΔZ=0 is obtained, and the tool is controlled to maintain the lifting state.

[0092] To address the issues of memory overflow and latency caused by real-time computation in the processing of million-level arrays, this embodiment proposes a "single-cell modeling + cycle reuse" strategy. Only the compensation matrix of a single cell (data volume <500 kB) needs to be calculated offline, and real-time table lookup is achieved through modular arithmetic, avoiding redundant calculations. Compared to traditional full-array table lookup (GB level), the data volume is reduced by more than three orders of magnitude, loading time is significantly reduced, and processing efficiency is improved. This mechanism is key to achieving efficient and stable processing of large-scale arrays.

[0093] S600: After generating the target two-dimensional compensation depth matrix, the method also includes the following sub-steps:

[0094] S610: This includes the target 2D compensation depth matrix, X / Y coordinate vectors, as well as parameters including aspherical parameters, tool parameters (tool radius, tool lift-off height), process parameters, and microlens unit period length parameters (P). x and P y The meta structure is encapsulated into a binary file to generate a lookup table file.

[0095] Before machining, the file is loaded into the machine tool control system memory in one go, so that the FTS module can call it in real time. This design solves the calculation delay and system instability problems caused by the "calculate and use" method in traditional methods, improves the real-time performance and reliability of CNC systems, and is particularly suitable for ultra-precision machine tools with high dynamic response.

[0096] The method of this invention was verified in the fabrication of a 1000×1000 large-scale microlens array. The key steps and results are as follows:

[0097] Coordinate transformation: The tool tip arc is discretized into 301 spatial points, and a rigid mapping from the tool coordinate system to the workpiece coordinate system is completed through a homogeneous transformation matrix, successfully achieving precise alignment between the tool posture and the workpiece position.

[0098] Contact point identification: Based on the aspherical equation and chain rule, the normal vector of the workpiece surface corresponding to each discrete point is calculated; by using the "minimum absolute value of inner product" criterion, the 21st discrete point in a single microlens unit is determined as the real contact point, ensuring accurate identification of the first entry position.

[0099] Compensation calculation: For this contact point, the Z-axis compensation is calculated as ΔZ=6.8742, which achieves tangential approximation between the tool tip and the aspherical surface, avoiding overcutting.

[0100] Compensation matrix generation: Traverse 100×101 tool positioning points to generate an initial two-dimensional compensation depth matrix, and set the non-machining area (unit gap) to zero to complete the full-area tooling strategy modeling.

[0101] Lookup file generation: The target two-dimensional compensation depth matrix and process parameters are encapsulated into a binary .mat file with a size of less than 500 kB, which can be instantly loaded by the machine tool and supports real-time lookup control.

[0102] Processing Results: A 1000×1000 microlens array was successfully processed, with a single lens processing time of only 0.14 seconds; the surface shape error PV < 0.1 μm, and the surface roughness Ra < 2 nm. These results demonstrate that the method of this invention can efficiently generate high-precision lookup table files, significantly improving processing efficiency and system stability while ensuring nanoscale processing quality, and possesses good engineering feasibility and industrial application prospects.

[0103] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0104] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, mobile terminal, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0105] In an exemplary embodiment of this disclosure, an electronic device capable of implementing the above-described method is also provided.

[0106] Those skilled in the art will understand that various aspects of the present invention can be implemented as systems, methods, or program products. Therefore, various aspects of the present invention can be specifically implemented in the following forms: entirely in hardware, entirely in software (including firmware, microcode, etc.), or in a combination of hardware and software, collectively referred to herein as “circuit,” “module,” or “system.”

[0107] An electronic device according to this embodiment of the invention. The electronic device is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the invention.

[0108] Electronic devices are manifested in the form of general-purpose computing devices. Components of an electronic device may include, but are not limited to: at least one processor, at least one memory, and buses connecting different system components (including memory and processor).

[0109] The memory stores program code that can be executed by a processor, causing the processor to perform the steps described in the "Exemplary Methods" section above, according to various exemplary embodiments of the present invention.

[0110] The storage may include readable media in the form of volatile storage, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0111] The storage may also include programs / utilities having a set (at least one) of program modules, including but not limited to: an operating system, one or more applications, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0112] A bus can represent one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus that uses any of the various bus architectures.

[0113] The electronic device can also communicate with one or more external devices (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (e.g., routers, modems, etc.). This communication can be performed via input / output (I / O) interfaces. Furthermore, the electronic device can communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter communicates with other modules of the electronic device via a bus. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0114] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the present invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the present invention described in the "Exemplary Methods" section above.

[0115] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0116] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0117] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0118] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0119] Furthermore, the accompanying drawings are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention and are not intended to be limiting. It is readily understood that the processes shown in the above drawings do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0120] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0121] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for obtaining the tool entry distance in large-scale microlens array fabrication, characterized in that, The method includes the following steps: For each tool positioning point within the aspherical surface region of the microlens unit, the tool tip arc is discretized into multiple spatial points and mapped to the workpiece coordinate system; the microlens unit is any microlens unit in a large-scale microlens array; Obtain the XY coordinates of each mapped tool discrete point, substitute them into the aspherical analytical expression of the microlens unit surface shape, and obtain the normal vector of the workpiece surface point corresponding to each mapped tool discrete point; Calculate the absolute value of the inner product of the tangent vector of each discrete point of the tool and the normal vector of the corresponding workpiece surface point, and select the discrete point of the tool with the smallest absolute value of the inner product as the actual contact point. Based on the difference between the Z coordinate of the actual contact point in the current tool lifting state and the Z coordinate of the corresponding workpiece surface point, the Z-axis compensation amount is calculated and used as the tool positioning point's down-tool distance.

2. The method according to claim 1, characterized in that, The step of discretizing the tool tip arc into multiple spatial points and mapping them to the workpiece coordinate system includes: In the tool coordinate system, the tool tip arc is uniformly discretized into N spatial points, forming a tool discrete point set; Calculate the three-dimensional coordinates of each discrete point in the tool coordinate system and its tangent vector; Set the preset tool lifting height and position the center of the tool arc to the XY position of the current tool positioning point; The tool discrete point set is rigidly transformed to the workpiece coordinate system using a homogeneous transformation matrix.

3. The method according to claim 1, characterized in that, The aspherical analytical expression of the microlens unit surface shape is substituted to obtain the normal vector of the corresponding workpiece surface point, including: Using the chain rule for equations of aspherical surfaces Find the derivative and calculate the partial derivative at the XY coordinates. and ; based on and Construct the gradient vector After normalization, we obtain the unit normal vector n.

4. The method according to any one of claims 1-3, characterized in that, The calculation of the Z-axis compensation based on the difference in Z-coordinates of the actual contact points includes: Obtain the Z-coordinate of the actual contact point in the rigid body after the transformation. tool contact ; Obtain the Z-coordinate of the workpiece surface point corresponding to the actual contact point. work contact ; Calculate the cutting distance ΔZ=z tool contact -z work contact This ensures that the tool tip arc is tangent to the workpiece surface, avoiding overcutting.

5. The method according to claim 1, characterized in that, The unit region corresponding to a single microlens unit includes the projection region of the aspherical surface shape in the XY plane and the unit gap region; After calculating the cutting distance for a single microlens unit, the method further includes: In the projection area of ​​the aspherical surface in the XY plane, the tool positioning distances of all tool positioning points are arranged according to their XY positions to generate an initial two-dimensional compensation depth matrix; Based on the initial two-dimensional compensation depth matrix, the tool down distance corresponding to all tool positioning points in the unit gap area is set to 0 to generate the target two-dimensional compensation depth matrix; Based on the target two-dimensional compensation depth matrix, the cutting distance corresponding to each tool positioning point in other microlens units of the large-scale microlens array is obtained.

6. The method according to claim 5, characterized in that, After generating the target two-dimensional compensation depth matrix, the method further includes: The target two-dimensional compensation depth matrix, X / Y coordinate vector, and meta structure containing aspherical parameters, tool parameters, process parameters, and microlens unit period length parameters are encapsulated into a binary file to generate a lookup table file; Before processing large-scale microlens arrays, the lookup table file is loaded into the machine tool control system memory for real-time retrieval.

7. The method according to claim 6, characterized in that, Based on the target two-dimensional compensation depth matrix, the tool drop distance corresponding to each tool positioning point in other microlens units of the large-scale microlens array is obtained, including: Real-time acquisition of the global coordinates (x) of the current tool positioning point global ,y global ); Based on the X-axis period length P of the microlens unit x and Y-axis period length P y The local relative coordinate x is calculated through modular arithmetic. local and y local x local and y local The following conditions must be met: x local =x global mod P x , y local =y global mod P y ; On the target two-dimensional compensation depth matrix and its corresponding X / Y coordinate vector, according to (x local ,y local Perform coordinate matching and data query to obtain the corresponding tool drop distance ΔZ.

8. The method according to claim 7, characterized in that, According to (x) local ,y local Coordinate matching and data querying include: If (x local ,y local If the surface falls into the projection area of ​​the aspherical surface, a non-zero compensation value ΔZ is obtained through bilinear interpolation or nearest neighbor interpolation to control the cutting of the fast tool servo system. If (x local ,y local If the tool falls into the unit gap area, the compensation value ΔZ=0 is obtained, and the tool is controlled to maintain the lifting state.

9. A non-transitory computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a method for obtaining the cutting distance for large-scale microlens array processing as described in any one of claims 1 to 8.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements a method for obtaining the cutting distance for large-scale microlens array processing as described in any one of claims 1 to 8.

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