A processing technology and processing system for microlens array on inner surface of hollow cylinder

Abstract

The present invention discloses a hollow cylindrical inner surface microlens array processing technology and processing system, the hollow cylindrical inner surface microlens array processing technology includes the following steps: S10: confirming that the morphological feature is within the servo processing range of the two-dimensional elliptical vibration device; S20: building a processing system; S30: obtaining tool parameters and cutting parameters; S40: generating the servo trajectory of the two-dimensional elliptical vibration device and the X-axis and Z-axis motion paths of the machine tool; S50: determining the processing compensation; S60: starting the processing system and performing processing. The processing system is used for the hollow cylindrical inner surface microlens array processing technology. The hollow cylindrical inner surface microlens array processing technology and processing system realize the processing of a microlens array with a free-form surface morphology on the inner surface of the cylinder, and can complete the processing of a three-dimensional structure, with high processing surface accuracy, surface roughness reaching the nanometer level, and a variety of processable materials.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-precision machining, and in particular to a machining process and a machining system for a microlens array on the inner surface of a hollow cylinder. Background Art

[0002] Today, microstructure arrays are a type of surface with regularly distributed microscopic geometric topological shapes and specific functions. They are key components in optoelectronics, information communications, precision engineering, and other fields. Examples include microlens arrays used in IC equipment light source systems, biomimetic compound eye structure arrays for target positioning, and microprism arrays for retroreflection in spatial optics. It is worth noting that, due to manufacturing process limitations, most previous microlens arrays could only be generated on flat surfaces. In recent years, inspired by various compound eye structures found in nature, people have gradually realized that microlens arrays on curved surfaces have superior performance compared to flat structures. For example, spherical compound eye structures are closer to real compound eyes in nature than flat compound eye structures, with a larger field of view and higher sensitivity. Therefore, it is particularly important to find ways to quickly and accurately generate microlens arrays with free-form surface morphologies on curved substrates.

[0003] In recent years, to meet the morphology and precision requirements of microlens arrays on curved substrates in industrial production, a number of fabrication technologies for microstructured surfaces have been proposed, including photolithography, energy beam fabrication, special energy field processing, and ultra-precision machining using diamond tools. Each method has its own unique advantages and disadvantages.

[0004] Photolithography is a technique that uses exposure and etching to transfer a planar geometric pattern from a mask onto a single crystal surface or substrate layer, forming a geometric pattern. Mohammad J. Moghimi et al. used photolithography to fabricate extremely high-resolution Fresnel lens arrays on the inner and outer surfaces of cylinders. Huan Hu et al. used nanolithography to fabricate microlenses on the outer surfaces of glass and silicon substrates, with a feature size of approximately 250 nm.

[0005] However, the existing photolithography technology also has significant disadvantages. The equipment cost is extremely high, and it is usually only used for the microstructure manufacturing of binary structures. It is not suitable for the processing and preparation of three-dimensional complex structures, especially three-dimensional free-form surface structures, and there are also strong constraints on the materials that can be processed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing photolithography technology is costly and can only be used for binary structures. The purpose is to provide a hollow cylindrical inner surface microlens array processing technology and processing system to solve the above problem.

[0007] The present invention is achieved through the following technical solutions:

[0008] In a first aspect, the present invention discloses a process for manufacturing a microlens array on the inner surface of a hollow cylinder, comprising the following steps:

[0009] S10: Design the free-form surface equation of the microlens array on the inner surface of the hollow cylinder based on the product's optical performance requirements. Based on the free-form surface equation of the microlens array, confirm that the topography is within the servo processing range of the two-dimensional elliptical vibration device.

[0010] S20: Build processing system;

[0011] S30: Obtain tool parameters and cutting parameters based on material cutting performance and fly cutter machining characteristics;

[0012] S40: Based on S10 and S20 and influencing factors, the servo trajectory of the two-dimensional elliptical vibration device and the motion paths of the X-axis and Z-axis of the machine tool are generated;

[0013] S50: determining machining compensation based on the turning radius of the fly cutter and the starting position of the tool tip in the machine tool coordinate system;

[0014] S60: Start the processing system and perform processing.

[0015] In one possible design, in S10, a single free-form lens includes an aspheric surface z1 and a spherical surface z2, and the equation is described as:

[0016]

[0017] f(x,y)=z1(x,y)+z2(x,y)

[0018] In the formula, h, k1, c1, R c , s1, s2 are all constants, and h=0.0025, k1=-0.5, c1=0.8, R c =0.3, s1=0.0081, s2=2.5, A represents the first aspheric coefficient; B represents the second aspheric coefficient; f(x, y) represents the free-form surface equation of the microlens array.

[0019] In a possible design, in S20 , the tool parameters include the radius, rake angle, and back angle of the tool tip; and the cutting parameters include the spindle speed, feed rate, and cutting depth.

[0020] In one possible design, S30 includes the following steps:

[0021] S41: The free-form surface equation of the microlens array f(x, y) in the interval (θ min ,θ max ) is linearly discretized into N+1 points;

[0022] S42: Based on workpiece coordinate system Ow x w y w z w , obtain the coordinates of the cutting edge at any point n in the workpiece coordinate system (x tw ,y tw , z tw ) and the tangent vector at point n

[0023]

[0024] Where θ i represents the angle corresponding to the i-th tool contact point on the cutting edge; i represents the i-th tool contact point on the cutting edge;

[0025] S43: The coordinates of point m on the workpiece corresponding to point n are Normal vector at point m

[0026]

[0027] β=-tan -1 (slope(i))

[0028] Where β represents the angle of rotation around the z-axis;

[0029] S44: The tangent vector of the actual cutting point on the cutting edge is perpendicular to the normal vector of the corresponding point on the design surface, that is, By searching all points on the cutting edge, the minimum value θ is obtained i value and determine the actual cutting point.

[0030] In one possible design, in S30, the influencing factors include tool radius compensation, material springback effect, and kinematic relationship.

[0031] In a possible design, in S40, based on the machine tool coordinate system O s x s y x z x , obtain the starting position of the tool tip in the machine tool coordinate system (R s ,γ0); Based on the starting position of the tool tip, angle compensation is performed in the servo trajectory of the two-dimensional elliptical vibration device.

[0032] In one possible design, in S40, the flying cutter's turning radius is obtained based on the flying cutter grooving experiment; when the flying cutter is assembled, the flying cutter's deviation angle is roughly aligned and estimated based on the tool microscope; and compensation correction is performed through cutting experiments.

[0033] In one possible design, in S50, the diamond tool is set on a flying cutter disc, the flying cutter disc is adsorbed on the machine tool spindle through an air suction cup, and the workpiece is fixed on a two-dimensional elliptical vibration device.

[0034] In one possible design, in S60, the machine tool spindle drives the diamond tool to rotate, and the machine tool X-axis and Z-axis perform feed motion respectively; based on the machine tool spindle position, the two-dimensional elliptical vibration device servo corresponds to the trajectory and controls the workpiece to move in the vertical direction.

[0035] In a second aspect, the present invention discloses a processing system for the microlens array processing technology on the inner surface of a hollow cylinder, comprising a machine tool, a flying cutter disc, a diamond tool, a vertical motion platform, a two-dimensional elliptical vibration device, and a control module;

[0036] The machine tool has an X-axis, a Z-axis and a spindle. The X-axis is provided with a base for mounting the spindle, and the Z-axis is located outside the X-axis and perpendicular to the X-axis.

[0037] The flying cutter disc is adsorbed on the machine tool spindle through an air suction cup, and the diamond tool is set on the flying cutter disc;

[0038] The vertical motion platform is arranged on the Z axis and can reciprocate along the Z axis, and the two-dimensional elliptical vibration device is arranged on the vertical motion platform and is used to place the workpiece;

[0039] The control module is electrically connected to and controls the machine tool, the flying cutter disc, the diamond cutter, the vertical motion platform and the two-dimensional elliptical vibration device.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] It can realize the processing of free-form micro-lens arrays on the inner surface of a cylinder and complete the processing of three-dimensional structures. The processing surface has high precision and the surface roughness reaches the nanometer level. It can process a variety of materials.

[0042] The diamond cutting process utilizes a fly-cutting process in conjunction with two-dimensional elliptical vibration. Controlling cutting and tool parameters improves cutting stability, traverses the designed complex cutting trajectory, and achieves ultra-precision machining of complex curved surfaces. This reduces the complexity of microstructure generation on cylindrical inner surfaces using traditional fast-tool servo and slow-tool servo methods, effectively ensuring the surface quality and performance of the lens array. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0044] Figure 1 A structural diagram of a processing system.

[0045] Figure 2 Schematic diagram of the basic principle of flying knife-two-dimensional elliptical vibration.

[0046] Figure 3 Schematic diagram of the servo trajectory calculation for a two-dimensional elliptical vibration device.

[0047] Markings and corresponding parts names in the accompanying drawings:

[0048] 1. Machine tool; 2. Flying cutter disc; 3. Diamond tool; 4. Vertical motion platform; 5. Two-dimensional elliptical vibration device. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0050] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not necessarily required to practice the present invention. In other embodiments, well-known structures, circuits, materials, or methods are not described in detail to avoid obscuring the present invention.

[0051] Throughout this specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Therefore, appearances of the phrases "one embodiment," "an embodiment," "an example," or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combinations and / or subcombinations. Furthermore, it will be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes only and are not necessarily drawn to scale. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0052] In the description of the present invention, the terms "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0053] Example 1:

[0054] like Figure 1-Figure 3 As shown, a process for manufacturing a microlens array on the inner surface of a hollow cylinder includes the following steps:

[0055] S10: Designing a free-form surface equation of the microlens array on the inner surface of the hollow cylinder based on the product optical performance requirements, and confirming that the topographical features are within the servo processing range of the two-dimensional elliptical vibration device 5 based on the free-form surface equation of the microlens array;

[0056] S20: Build processing system;

[0057] S30: Obtain tool parameters and cutting parameters based on material cutting performance and fly cutter machining characteristics;

[0058] S40: Based on S10 and S20 and influencing factors, the servo trajectory of the two-dimensional elliptical vibration device 5 and the X-axis and Z-axis motion paths of the machine tool 1 are generated;

[0059] S50: Determine machining compensation based on the turning radius of the fly cutter and the starting position of the tool tip in the coordinate system of the machine tool 1;

[0060] S60: Start the processing system and perform processing.

[0061] In the hollow cylinder inner surface microlens array processing process, in S10, the servo processing range of the two-dimensional elliptical vibration device 5 is known. By obtaining the free-form surface equation of the microlens array on the inner surface of the hollow cylinder, the design value required for the product to form the free-form surface morphology feature during a single processing process can be confirmed. The design value is also the required servo processing range of the two-dimensional elliptical vibration device 5. By comparing the design value with the known value, it can be confirmed that the morphology feature is within the servo processing range of the two-dimensional elliptical vibration device 5.

[0062] If the processing requirements are met, the corresponding two-dimensional elliptical vibration device 5 is used and the subsequent steps are continued; if the processing requirements are not met, another type of two-dimensional elliptical vibration device 5 is replaced until the requirements are met.

[0063] In S20, the processing system is built, and in the subsequent process of determining the processing parameters, the processing system can be directly debugged, or a trial run can be performed through the processing system to facilitate timely adjustments.

[0064] In S30, appropriate tool parameters and appropriate cutting parameters are selected based on the material cutting performance and fly cutter machining characteristics to ensure the quality of the machined surface.

[0065] In S40, the trajectory of each moving component in the processing system is confirmed, and the feed motion of each moving component is controlled and coordinated through the control module to complete the processing of specific topographic features, thereby achieving automated processing while ensuring processing quality.

[0066] In S50, the machining parameters are further determined, and machining compensation is performed to eliminate errors in the machining system to ensure the quality of the machined surface. At the same time, since the machining system has been established, debugging is performed directly on the machining system to eliminate errors and achieve compensation.

[0067] In S60, the relevant preparations have been completed and the processing system can be started for processing.

[0068] Specifically:

[0069] In a possible implementation, in S10, a single free-form surface lens includes an aspherical surface z1 and a spherical surface z2, and the equation is described as:

[0070]

[0071] f(x,y)=z1(x,y)+z2(x,y)

[0072] In the formula, h, k1, c1, R c , s1, s2 are all constants, and h=0.0025, k1=-0.5, c1=0.8, R c =0.3, s1=0.0081, s2=2.5, A represents the first aspheric coefficient; B represents the second aspheric coefficient; f(x, y) represents the free-form surface equation of the microlens array.

[0073] Based on the above design scheme, based on the respective representation equations of the aspheric surface z1 and the spherical surface z2, the equation of the free-form surface of the microlens array can be obtained. The equation of the free-form surface of the microlens array is compared with the processing range of the processing system. If it is within the processing range of the processing system, it can be processed by the processing system. On the contrary, if it is outside the processing range of the processing system, other models of processing systems are replaced to complete the processing.

[0074] In a possible implementation, in S20 , the diamond tool 3 is set on the fly cutter disc 2 , the fly cutter disc 2 is adsorbed on the main shaft of the machine tool 1 through an air suction cup, and the workpiece is fixed on the two-dimensional elliptical vibration device 5 .

[0075] Based on the above design scheme, the other components of the machine tool 1 have been connected. Depending on the processing requirements, any suitable diamond tool 3 can be selected. When the diamond tool 3 is used for cutting, compared with other optical or electronic manufacturing methods, its advantage is that it can obtain higher three-dimensional shape accuracy and surface roughness. In addition, it has the ability to manufacture free-form surfaces, which is very important for the manufacture of optical components.

[0076] In a possible implementation, in S30 , the tool parameters include the radius, rake angle, and clearance angle of the tool tip; and the cutting parameters include the spindle speed, feed rate, and cutting depth.

[0077] Based on the above design scheme, an appropriate tool is selected based on the tool parameters and installed on the machining system to complete the machining process using the selected tool. Cutting parameters are determined based on the specific tool model and the specific machining requirements. Furthermore, tool and cutting parameters, in addition to the parameters listed above, may also include any other appropriate parameters to meet specific machining requirements.

[0078] In a possible implementation, S40 includes the following steps:

[0079] S41: The free-form surface equation of the microlens array f(x, y) in the interval (θ min ,θ max ) is linearly discretized into N+1 points;

[0080] S42: Based on workpiece coordinate system O w x w y w z w , obtain the coordinates of the cutting edge at any point n in the workpiece coordinate system (x tw ,y tw , z tw ) and the tangent vector at point n

[0081]

[0082] Where θ i represents the angle corresponding to the i-th tool contact point on the cutting edge; i represents the i-th tool contact point on the cutting edge;

[0083] S43: The coordinates of point m on the workpiece corresponding to point n are Normal vector at point m

[0084]

[0085] B=-tan -1 (slope(i))

[0086] Where β represents the angle of rotation around the z-axis;

[0087] S44: The tangent vector of the actual cutting point on the cutting edge is perpendicular to the normal vector of the corresponding point on the design surface, that is, By searching all points on the cutting edge, the minimum value θ is obtained i value and determine the actual cutting point.

[0088] Based on the above design scheme, the processing system realizes processing through a single-point diamond cutting process. However, in this process, the actual cutting edge contact point always changes, and the radius of the tool also affects the processing quality.

[0089] For the actual cutting edge contact point, such as Figure 3 As shown, there are three coordinate systems in the machining system: tool coordinate O t x t y t z t , located on the rake face of the diamond tool, is used to describe the cutting edge morphology of the diamond tool; the spindle coordinate system is O s x s y x z x , located at the center of the machine tool spindle; the workpiece coordinate system is O w x w y w z w , on the workpiece surface.

[0090] On the basis of the above three coordinate systems, accurate numerical calculations are performed through S41-S44 to obtain all actual cutting points, so that the processing parameters are more accurate, the processed morphological features are more accurate, and the processing quality of the processing system is higher.

[0091] In one possible implementation, in S40, the influencing factors include tool radius compensation, material rebound effects, and kinematic relationships. Based on the above design scheme and in combination with the actual cutting points obtained in S41-S44, the servo trajectory of the two-dimensional elliptical vibration device 5 and the X-axis and Z-axis motion paths of the machine tool are generated. Furthermore, in addition to the parameters listed above, the influencing factors may also include any other appropriate parameters to meet specific processing requirements.

[0092] In a possible implementation, in S50, based on the machine tool coordinate system O s x s y x z x, obtain the starting position of the tool tip in the machine tool coordinate system (R s , γ0); based on the starting position of the tool tip, angle compensation is performed in the servo trajectory of the two-dimensional elliptical vibration device 5.

[0093] Based on the above design, during tool installation, the tool is fixed to the spindle of machine tool 1 and parallel to the horizontal axis of machine tool 1. However, due to installation errors, a deviation angle exists after the tool is installed. Using a tool setting microscope during installation can reduce the deviation angle, but it cannot eliminate it. Therefore, angle compensation is used to further reduce the deviation angle. Based on the servo trajectory of the two-dimensional elliptical vibration device 5 obtained in S40, compensation can be performed using any suitable existing method.

[0094] In one possible implementation, in S50, based on the fly cutter grooving experiment, the fly cutter rotation radius is obtained; when the fly cutter is assembled, the fly cutter deviation angle is roughly aligned and estimated based on the tool setting microscope; and compensation correction is performed through the cutting experiment;

[0095] Based on the above design scheme, taking the established processing system as the benchmark, the processing parameters, such as the flying cutter rotation radius, are obtained through actual processing. At the same time, debugging is also carried out through cutting experiments to reduce the deviation angle.

[0096] Optionally, during the fly-cut grooving experiment, the curvature radius of the groove is measured by a white light interferometer to obtain the fly-cut grooving radius.

[0097] In one possible implementation, in S60, the spindle of the machine tool 1 drives the diamond tool 3 to rotate, and the X-axis and Z-axis of the machine tool 1 perform feed motion respectively; based on the spindle position of the machine tool 1, the two-dimensional elliptical vibration device 5 servo corresponds to the trajectory and controls the workpiece to move in the vertical direction.

[0098] Based on the above design scheme, the X-axis, Z-axis and two-dimensional elliptical vibration device 5 of the machine tool 1 cooperate with each other to complete the processing of the workpiece. The two-dimensional elliptical vibration device 5 servo corresponds to the trajectory and controls the movement of the workpiece in the vertical direction, thereby realizing the processing and preparation of three-dimensional complex structures, expanding the processing range, and improving practicality.

[0099] This embodiment introduces a processing system for the processing of a microlens array on the inner surface of a hollow cylinder based on the processing technology of the microlens array on the inner surface of a hollow cylinder. The processing system includes a machine tool 1, a flying cutter head 2, a diamond tool 3, a vertical motion platform 4, a two-dimensional elliptical vibration device 5, and a control module.

[0100] The machine tool 1 has an X-axis, a Z-axis and a spindle, wherein the X-axis is provided with a base for mounting the spindle, and the Z-axis is located outside the X-axis and perpendicular to the X-axis;

[0101] The flying cutter disc 2 is adsorbed on the main shaft of the machine tool 1 through an air suction cup, and the diamond tool 3 is set on the flying cutter disc 2;

[0102] The vertical motion platform 4 is arranged on the Z axis and can reciprocate along the Z axis. The two-dimensional elliptical vibration device 5 is arranged on the vertical motion platform 4 and is used to place the workpiece.

[0103] The control module is electrically connected to and controls the machine tool 1 , the flying cutter disc 2 , the diamond tool 3 , the vertical motion platform 4 and the two-dimensional elliptical vibration device 5 .

[0104] In the machining system, the machine tool 1 can be any suitable existing model. The fly cutter head 2 and diamond tool 3 are both detachably connected to facilitate replacement of the diamond tool 3 to meet specific machining requirements. A vertical motion platform 4 is connected to a two-dimensional elliptical vibration device 5, which secures the position of the workpiece. The vertical motion platform 4 can be raised and lowered, both for assembly and disassembly of the workpiece and for adjusting the workpiece to a desired height before machining.

[0105] The two-dimensional elliptical vibration device 5 obtains the spindle output data of the machine tool 1 through the control module, thereby determining the real-time position of the spindle. Based on the real-time position of the spindle, the two-dimensional elliptical vibration device 5 servos the corresponding trajectory and controls the vertical motion of the workpiece, ultimately forming a lens array with a free-form surface morphology.

[0106] Correspondingly, the two-dimensional elliptical vibration device 5 is provided with components such as a capacitive displacement sensor and a piezoelectric ceramic driver. Among them, the capacitive displacement sensor is used to obtain the spindle output data of the machine tool 1 and transmit it to the control module, and the piezoelectric ceramic driver makes the two-dimensional elliptical vibration device 5 servo the trajectory of the spindle according to the instructions of the control module.

[0107] It is easy to understand that in the processing system, the moving parts include the movements of the X-axis, Z-axis and main spindle mainly based on the machine tool 1, and the movement mainly based on the two-dimensional elliptical vibration device 5. The control module can electrically connect the two at the same time and control their operation; or, the control module includes two sub-units, each sub-unit is electrically connected to one of the machine tool 1 and the two-dimensional elliptical vibration device 5 and controls its operation.

[0108] Example 2:

[0109] This embodiment provides a practical processing scheme based on embodiment 1:

[0110] The workpiece material is copper or aluminum, and the microstructure feature size is within 70μm.

[0111] The stiffness of the two-dimensional elliptical vibration device 5 in the X and Y directions is 16.37 N / μm and 9.10 N / μm respectively, and the displacement is 75 μm and 90 μm. The structural size characteristics of the workpiece are within the processing capability of the two-dimensional elliptical vibration device 5.

[0112] Based on the hollow cylindrical inner surface microlens array processing technology in Example 1, the spindle speed is 30 rpm, the tool tip radius is 0.2 mm, and the Z-direction feed amount is 5 μm, thereby achieving a high-precision free-form surface microlens array.

[0113] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for processing a microlens array on the inner surface of a hollow cylinder, characterized in that: The following steps are involved: S10: Designing a free-form surface equation of the microlens array on the inner surface of the hollow cylinder based on the product optical performance requirements, and confirming that the morphological characteristics of the microlens array on the inner surface of the hollow cylinder are within the servo processing range of the two-dimensional elliptical vibration device (5) based on the free-form surface equation of the microlens array; S20: Build processing system; S30: Obtain tool parameters and cutting parameters based on material cutting performance and fly cutter machining characteristics; S40: Based on S10 and S20 and influencing factors, a servo trajectory of the two-dimensional elliptical vibration device (5) and the X-axis and Z-axis motion paths of the machine tool (1) are generated; S50: determining machining compensation based on the turning radius of the fly cutter and the starting position of the tool tip in the coordinate system of the machine tool (1); S60: Start the processing system and perform processing; In S10, a single free-form surface lens includes an aspheric surface z1 and a spherical surface z2, and the equation is described as: f(x,y)=z1(x,y)+z2(x,y) In the formula, h, k1, c1, R c , s1, s2 are all constants, and h=0.0025, k1=-0.5, c1=0.8, R c =0.3, s1=0.0081, s2=2.5, A represents the first aspheric coefficient; B represents the second aspheric coefficient; f(x, y) represents the free-form surface equation of the microlens array; S40 includes the following steps: S41: The free-form surface equation of the microlens array f(x,y) in the interval (θ min ,θ max ) is linearly discretized into N+1 points; S42: Based on workpiece coordinate system O w x w y w z w , obtain the coordinates of the cutting edge at any point n in the workpiece coordinate system (x tw ,y tw , z tw ) and the tangent vector at point n Where θ i represents the angle corresponding to the i-th tool contact point on the cutting edge; i represents the i-th tool contact point on the cutting edge; S43: The coordinates of point m on the workpiece corresponding to point n are Normal vector at point m β=-tan -1 (slope(i)) Where β represents the angle of rotation around the z-axis; S44: The tangent vector of the actual cutting point on the cutting edge is perpendicular to the normal vector of the corresponding point on the design surface, that is, By searching all points on the cutting edge, the minimum value θ is obtained i The value of and determine the actual cutting point; In S40, the influencing factors include tool radius compensation, material springback effect and kinematic relationship.

2. The hollow cylindrical inner surface microlens array processing process according to claim 1, characterized in that: In S20, the diamond tool (3) is set on the flying cutter disc (2), the flying cutter disc (2) is adsorbed on the main shaft of the machine tool (1) through an air suction cup, and the workpiece is fixed on the two-dimensional elliptical vibration device (5).

3. The process for processing a microlens array on the inner surface of a hollow cylinder according to claim 2, wherein: In S30, the tool parameters include the radius, rake angle, and back angle of the tool tip; and the cutting parameters include the spindle speed, feed rate, and cutting depth.

4. The process for processing a microlens array on the inner surface of a hollow cylinder according to claim 1, wherein: In S50, based on the machine tool coordinate system O s x s y x z x , obtain the starting position of the tool tip in the machine tool coordinate system (R s ,γ0); Based on the starting position of the tool tip, angle compensation is performed in the servo trajectory of the two-dimensional elliptical vibration device (5).

5. The process for processing a microlens array on the inner surface of a hollow cylinder according to claim 1 or 4, characterized in that: In S50, the flying cutter's turning radius is obtained based on the flying cutter grooving experiment; when the flying cutter is assembled, the flying cutter's deviation angle is roughly aligned and estimated based on the tool setting microscope; and compensation correction is performed through cutting experiments.

6. The process for processing a microlens array on the inner surface of a hollow cylinder according to claim 5, characterized in that: In S60, the main shaft of the machine tool (1) drives the diamond tool (3) to rotate, and the X-axis and Z-axis of the machine tool (1) respectively perform feed motion; based on the position of the main shaft of the machine tool (1), the two-dimensional elliptical vibration device (5) servo corresponds to the trajectory and controls the workpiece to move in the vertical direction.

7. A processing system for the hollow cylindrical inner surface microlens array processing process according to any one of claims 1 to 6, characterized in that: It includes a machine tool (1), a flying cutter disc (2), a diamond tool (3), a vertical motion platform (4), a two-dimensional elliptical vibration device (5) and a control module; The machine tool (1) has an X-axis, a Z-axis and a main spindle, wherein the X-axis is provided with a base for mounting the main spindle, and the Z-axis is located outside the X-axis and perpendicular to the X-axis; The flying cutter disc (2) is adsorbed on the main shaft of the machine tool (1) through an air suction cup, and the diamond tool (3) is arranged on the flying cutter disc (2); The vertical motion platform (4) is arranged on the Z axis and can reciprocate along the Z axis. The two-dimensional elliptical vibration device (5) is arranged on the vertical motion platform (4) and is used to place a workpiece. The control module is electrically connected to and controls the machine tool (1), the flying cutter disc (2), the diamond tool (3), the vertical motion platform (4) and the two-dimensional elliptical vibration device (5).

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