A polishing method for an optical component with a convex spherical surface

Abstract

The present application provides a polishing method for an optical component with a convex spherical surface, comprising the following steps: providing a protective member and placing the protective member on the back of the optical component; using a first polishing tool and a second polishing tool to perform rough polishing on the convex spherical surface on the front of the optical component, wherein the convex spherical surface includes a local arcuate surface located in the middle and a local annular surface located on the outside, the first polishing tool being used for rough polishing the local arcuate surface, and the second polishing tool being used for rough polishing the local annular surface; using a third polishing tool and a fourth polishing tool to perform fine polishing on the convex spherical surface on the front of the optical component after rough polishing, wherein the third polishing tool is used for fine polishing the local arcuate surface, and the fourth polishing tool is used for fine polishing the local annular surface; and separating the finely processed optical component from the protective member. This method solves the problem that existing polishing processes cannot perform full coverage polishing on small convex spherical surfaces on planar substrates.

Description

Technical Field

[0001] The present application relates to the technical field of optical component processing, and more particularly to a polishing method for an optical component with a convex spherical surface. Background Art

[0002] For mechanical polishing of optical parts, the traditional polishing process usually uses optical grinding tools (polishing pads) on a polishing machine for grinding and polishing. Traditional polishing pads can usually fully polish the flatter surfaces of optical parts, but cannot fully polish the small-diameter spherical surfaces on flat glass plates.

[0003] See also Figure 3 For example, in an optical component 10, there is at least one convex spherical surface 12 on a planar substrate 11 (specifically, both convex spherical surfaces 12 need to be polished, and the diameters of the two convex spherical surfaces 12 are different, both less than 5 mm. The thickness of the planar substrate 11 is 0.3 mm (and the two convex spherical surfaces 12 of the optical component 10 are both located in a groove 13, and the bottom surface of the groove 13 is the surface of the planar substrate 11). The surface roughness of the polished convex spherical surface 12 is Rq < 80 nm, the polished surface shape requirement PV < 3.5λ@633 nm, the polishing grade is P2, and the annular structure is the coating area 14, which needs to be protected from damage during the polishing process. Due to insufficient equipment processing range and mold size manufacturing capabilities, optical components of this structure and size cannot be processed.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] The purpose of the present application is to provide a polishing method for an optical component with a convex spherical surface, which solves the problem that the existing polishing process cannot perform full coverage polishing on the small convex spherical surface on the flat substrate.

[0006] To achieve the above objectives, the technical solution adopted in this application is:

[0007] The present application provides a polishing method for an optical component with a convex spherical surface, comprising the steps of:

[0008] providing a protective member, and setting the protective member on the back side of the optical member;

[0009] Roughly polishing the convex spherical surface of the front surface of the optical component using a first polishing tool and a second polishing tool, wherein the convex spherical surface includes a partial arc-shaped surface located in the middle and a partial annular surface located on the outside, the first polishing tool is used for rough polishing the partial arc-shaped surface, and the second polishing tool is used for rough polishing the partial annular surface;

[0010] The convex spherical surface of the front surface of the optical component after rough polishing is finely polished by a third polishing tool and a fourth polishing tool, wherein the third polishing tool is used for fine polishing a local arcuate surface, and the fourth polishing tool is used for fine polishing a local annular surface;

[0011] Separate the finished optical component from the protective component.

[0012] In an optional embodiment, the step of providing a protective member and arranging the protective member on the back side of the optical member specifically includes:

[0013] The protective member includes a protective glass with a cavity, and the protective glass is heated;

[0014] Apply a hot melt adhesive layer on the side of the protective glass provided with the air escape groove;

[0015] The side of the protective glass provided with the air avoidance groove is bonded to the back of the optical component through a hot melt adhesive layer, wherein the air avoidance groove is used to avoid the coating area on the back of the optical component.

[0016] In an optional embodiment, the step of rough-polishing the convex spherical surface of the front surface of the optical component by using the first polishing tool and the second polishing tool respectively specifically includes:

[0017] Dropping a polishing auxiliary material mixture of a first concentration into the groove on the front surface of the optical component so that the liquid level of the polishing auxiliary material mixture is above the top of the convex spherical surface;

[0018] Roughly polishing the local arc surface of the convex spherical surface by using a first polishing tool, wherein the surface area of ​​the local arc surface accounts for a maximum of three quarters of the surface area of ​​the convex spherical surface;

[0019] The partial annular surface of the convex spherical surface is roughly polished by a second polishing tool, wherein the diameter of the top end of the second polishing tool is smaller than the diameter of the top end of the first polishing tool.

[0020] In an optional embodiment, in the step of roughly polishing the local arc-shaped surface of the convex spherical surface by using the first polishing abrasive tool:

[0021] The first polishing tool is tilted and contacts the local arc surface of the convex spherical surface;

[0022] Gradually increase the polishing speed of the first polishing abrasive to reach the first rough polishing speed;

[0023] During the polishing process using the first rough polishing speed, the tilt angle of the first polishing tool is adjusted within a predetermined range, and the optical component is rotated around the center point of the convex spherical surface at an arbitrary angle from time to time.

[0024] In an optional embodiment, in the step of roughly polishing the local arc-shaped surface of the convex spherical surface by using the first polishing abrasive tool:

[0025] Stopping the machine at a first predetermined interval to observe the polishing auxiliary material mixture, and adding the polishing auxiliary material mixture when the liquid level of the polishing auxiliary material mixture is lower than the top of the convex spherical surface;

[0026] The roughly polished partially curved surface is subjected to light inspection at intervals of a second predetermined time to ensure that the roughly polished partially curved surface meets the rough polishing quality standard.

[0027] In an optional embodiment, in the step of fine-polishing the convex spherical surface of the front surface of the optical component after rough polishing by the third polishing tool and the fourth polishing tool respectively:

[0028] dripping a polishing auxiliary material mixture of a second concentration into the groove on the front surface of the optical component so that the liquid level of the polishing auxiliary material mixture submerges the top of the convex spherical surface, wherein the second concentration is higher than the first concentration;

[0029] performing fine polishing on the partially curved surface after rough polishing by a third polishing abrasive tool, wherein the roughness of the third polishing abrasive tool is less than that of the first polishing abrasive tool, and gradually increasing the polishing speed of the third polishing abrasive tool to reach a second fine polishing speed, wherein the second fine polishing speed is less than the first rough polishing speed;

[0030] The partial annular surface of the convex spherical surface is finely polished by a fourth polishing tool, wherein the top diameter of the fourth polishing tool is smaller than the top diameter of the third polishing tool.

[0031] In an optional embodiment, the step of separating the finely processed optical component from the protective component specifically includes:

[0032] A cleaning tray is provided, and the polished optical component with the protective component is placed in the cleaning tray containing the cleaning liquid;

[0033] The cleaning liquid in the cleaning tray is heated to melt the hot melt adhesive layer between the polished optical component and the protective component;

[0034] Remove the polished optic from the protector and clean it.

[0035] In an optional embodiment, in the step of heating the cleaning liquid in the cleaning tray to melt the hot melt adhesive layer between the polished optical component and the protective component:

[0036] providing a heating pan, wherein hot water is contained in the heating pan, wherein the temperature of the hot water is higher than a preset temperature;

[0037] A cleaning tray containing cleaning liquid and the polished optical component with a protective component is placed on the heating tray and left to stand for a predetermined time.

[0038] In an optional embodiment, before the step of applying the hot melt adhesive layer on the heated surface of the protective glass, the step further includes:

[0039] The polished optical component with the protective component is sequentially ultrasonically cleaned in different cleaning tanks, wherein the different cleaning tanks sequentially include: a strong alkali tank, a weak alkali tank, a first water washing tank, and a second water washing tank.

[0040] In an optional embodiment, after the step of separating the finely processed optical component from the protective component, the method further comprises:

[0041] After the separated optical components are left to stand at room temperature for a predetermined period of time, the optical components are subjected to a final inspection.

[0042] The polishing method for an optical component with a convex spherical surface provided in the present application has at least the following beneficial effects: by placing a protective member on the back of the optical component to support the optical component and protect the back of the optical component, the convex spherical surface on the front of the optical component is rough-polished by a first polishing tool and a second polishing tool, respectively. The first polishing tool quickly polishes the easily machined local curved surface, while the second polishing tool quickly polishes the difficult-to-machine local annular surface, thereby achieving rough polishing of the entire convex spherical surface, increasing the polishing volume and improving polishing efficiency. The convex spherical surface on the front of the optical component after rough polishing is fine-polished by a third polishing tool and a fourth polishing tool, respectively. The third polishing tool fine-polishes the easily machined local curved surface, while the fourth polishing tool fine-polishes the difficult-to-machine local annular surface, thereby achieving fine polishing of the entire convex spherical surface, reducing the polishing volume and ensuring that the entire convex spherical surface meets high-precision requirements for roughness, surface shape, and polishing grade. After separating the finely machined optical component from the protective member, the finished optical component is obtained. When this processing scheme is used to polish a spherical surface with a diameter of less than 5 mm on a flat substrate, the second polishing abrasive tool and the fourth polishing abrasive tool can be used to polish the local annular surface that is difficult to process. In addition, the roughness, surface shape, and polishing grade of the optical component can be stably controlled during the polishing process, so that this type of optical component product can meet the technical index requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 A flowchart of the main steps of a polishing method for an optical component with a convex spherical surface provided in an embodiment of the present application;

[0045] Figure 2A flowchart of the detailed steps of a polishing method for an optical component with a convex spherical surface provided in an embodiment of the present application;

[0046] Figure 3 A partial cross-sectional view of a protective member and an optical member after being fixed, used in a polishing method for an optical member with a convex spherical surface provided in an embodiment of the present application;

[0047] Figure 4 A schematic structural diagram of a polishing abrasive tool used in a polishing method for an optical component with a convex spherical surface provided in an embodiment of the present application;

[0048] Figure 5 A schematic diagram of a polishing method for an optical component with a convex spherical surface provided in an embodiment of the present application when polishing a local curved surface;

[0049] Figure 6 A schematic diagram of a polishing method for an optical component with a convex spherical surface provided in an embodiment of the present application when polishing a local annular surface;

[0050] Figure 7 The anti-touch angle α in the polishing method for an optical component with a convex spherical surface provided in the embodiment of the present application is x Schematic diagram, Figure 7 (1) is the anti-touch angle α at different positions when a convex spherical surface is polished x Schematic diagram, Figure 7 (2) is the anti-touch angle α at different positions when polishing another convex spherical surface x Schematic diagram of;

[0051] Figure 8 A schematic structural diagram of a polishing method for an optical component with a convex spherical surface provided in an embodiment of the present application when separating the optical component.

[0052] Among them, the reference numerals in the figures are:

[0053] 10. Optical part; 11. Plane substrate; 12. Convex spherical surface; 13. Groove; 14. Coating area; 20. Protective part; 21. Protective glass; 22. Air avoidance groove; 23. Hot melt adhesive layer; 30. First polishing abrasive; 31. Cylindrical polishing end; 32. Connecting rod; 40. Second polishing abrasive; 41. Conical polishing end; 50. Third polishing abrasive; 60. Fourth polishing abrasive; 70. Heating plate; 71. Cleaning plate. DETAILED DESCRIPTION

[0054] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0055] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be located directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on this technical solution. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0056] The explanations of some professional terms involved in this embodiment are as follows:

[0057] Surface roughness refers to the unevenness of the machined surface, characterized by small peaks and valleys. The distance between two peaks or valleys (wave pitch) is very small (less than 1 mm), and it is a microscopic geometric error. The smaller the surface roughness, the smoother the surface.

[0058] Surface shape: PV (Peak to Valley), also known as peak-to-valley value, is a common indicator of optical surface shape quality. It refers to the height difference between the highest and lowest points within the sampling range (based on 2D contours or 3D data maps), after removing the reference surface.

[0059] Polishing grade: corresponds to the number N of tiny defects allowed within the 10mm sampling range.

[0060] Micro defects: small and irregular defects (generally less than 1μm in size) on the mirror surface.

[0061] This embodiment provides a polishing method for an optical component with a convex spherical surface, which is specifically as follows:

[0062] See also Figure 3This embodiment provides a polishing method for an optical component with a convex spherical surface, for polishing at least one convex spherical surface 12 on a planar substrate 11. For example, an optical component 10 has a groove 13 on the front surface, and two convex spherical surfaces 12 are provided on the bottom surface of the groove 13. The diameters of the two convex spherical surfaces 12 are both less than 5 mm. A coating area 14 is provided on the back surface of the optical component 10. The surfaces of the two convex spherical surfaces 12 are required to be polished, with a polished surface roughness of Rq < 80 nm, a polished surface shape requirement of PV < 3.5λ@633 nm, and a polishing grade of P2. The coating area 14 on the back surface has already been coated and cannot be damaged during the polishing process.

[0063] See also Figure 1 To achieve the polishing requirements of the above optical components, a polishing method for an optical component with a convex spherical surface in this embodiment mainly includes the following steps:

[0064] Step S100: providing a protective member, and placing the protective member on the back of the optical member.

[0065] For details, please refer to Figure 3 The protective member 20 is fixed to the back of the optical member 10 to support the thinner part of the optical member 10 and prevent the optical member 10 from being damaged by excessive polishing pressure during polishing. In addition, an air avoidance groove 22 is provided on the surface of the protective member 20 connected to the side of the optical member 10 to prevent the coating area 14 on the back of the optical member 10 from being scratched.

[0066] See also Figure 1 、 Figure 2 Therefore, step S100 specifically includes:

[0067] Step S110: The protective member includes a protective glass with a gas-proof groove, and the protective glass is heated.

[0068] For details, please refer to Figure 3 The protective glass 21 has a certain thickness. The protective glass 21 can support the area where the groove 13 of the optical component 10 is located, preventing the bottom wall of the groove 13 from being too thin and deforming under stress during the polishing process. A clearance groove 22 is provided on the front of the protective glass 21. Its shape corresponds to the shape of the coating area (or other area that needs protection or clearance) on the back of the optical component 10 that needs protection. Therefore, when the coating area is annular, the clearance groove 22 can be annular. When the protective glass 21 is connected to the back of the optical component 10, the coating area is located within the notch of the clearance groove 22, so that the coating area will not be damaged.

[0069] After wiping the prepared protective glass 21 clean with acetone or alcohol, place the protective glass 21 with the air-avoiding groove 22 facing upward, and heat the protective glass 21 on an electric stove to a predetermined temperature. The predetermined temperature can melt the hot-melt adhesive layer used to bond the protective glass 21 and the optical component 10. For example, the predetermined temperature can be 90°C.

[0070] Step S120: applying a hot melt adhesive layer on the side of the protective glass where the air-avoiding groove is provided.

[0071] In a specific process, the hot melt adhesive layer 23 can be made of white wax, which is evenly applied on the side of the heated protective glass 21 having the air-avoiding groove 22 structure.

[0072] Step S130 , bonding the side of the protective glass having the air-avoidance groove to the back side of the optical component through a hot-melt adhesive layer, wherein the air-avoidance groove is used to avoid the coating area on the back side of the optical component.

[0073] In the specific process, after the hot melt adhesive layer 23 (white wax) melts and softens, the back of the optical component 10 is glued to the white wax layer. After the optical component 10 and the protective glass 21 are completely cooled to room temperature, the optical component 10 and the protective glass 21 are fixed and prepared for the next step of polishing.

[0074] See also Figure 1 In step S200, the convex spherical surface on the front surface of the optical component is rough-polished by using a first polishing tool and a second polishing tool respectively, wherein the convex spherical surface includes a local arc-shaped surface located in the middle and a local annular surface located on the outside. The first polishing tool is used for rough-polishing the local arc-shaped surface, and the second polishing tool is used for rough-polishing the local annular surface.

[0075] For details, please refer to Figure 4 、 Figure 5 、 Figure 6 , different areas of the convex spherical surface 12 on the front side of the optical component 10 are rough-machined by the first polishing tool 30 and the second polishing tool 40. The polishing surface range of the first polishing tool 30 is relatively large, and it can polish large areas that are easy to polish, such as large surfaces. The polishing surface range of the second polishing tool 40 is relatively small, and it can polish small areas that are difficult to polish, such as small gaps and small corners. Different polishing tools are used according to different areas on the convex spherical surface 12. Specifically, the entire surface of the convex spherical surface 12 is divided into: a local arc-shaped surface located in the middle of the convex spherical surface 12 and a local annular surface surrounding the outside of the local arc-shaped surface. The local arc-shaped surface has a relatively large range, and the polishing tool can be tilted to polish this area. The local annular surface is a surface area close to the outer edge of the convex spherical surface 12, so the space is small and it is not easy for the polishing tool to extend into this position to perform surface polishing.

[0076] In this embodiment, the surface area of ​​the partially curved surface accounts for a maximum of three-quarters of the surface area of ​​the convex spherical surface. Therefore, the ratio of the surface area of ​​the partially curved surface to the surface area of ​​the partially annular surface is no greater than 3:1. The first polishing tool rapidly polishes the easily machined partially curved surface, while the second polishing tool rapidly polishes the less easily machined partially annular surface. This achieves rough polishing of the entire convex spherical surface, increasing the polishing volume and improving polishing efficiency.

[0077] See also Figure 1 、 Figure 2 Therefore, step S200 specifically includes:

[0078] Step S210: dripping a polishing auxiliary material mixture of a first concentration into the groove on the front surface of the optical component so that the liquid level of the polishing auxiliary material mixture is above the top of the convex spherical surface.

[0079] In the specific process, a mixture of cerium oxide with a particle size of 0.7-0.8μ and pure water with a first concentration is used as the polishing auxiliary material mixture. The first concentration can be 0.15g / ml. The polishing auxiliary material mixture is dropped into the groove of the optical part with a rubber-tipped dropper so that the liquid level of the polishing auxiliary material mixture is above the top of the convex spherical surface.

[0080] Step S220 : Roughly polishing the local arc-shaped surface of the convex spherical surface using a first polishing tool, wherein the surface area of ​​the local arc-shaped surface accounts for a maximum of three quarters of the surface area of ​​the convex spherical surface.

[0081] See also Figure 4 、 Figure 5 In the specific process, the first polishing tool 30 can use a wool polishing head, which is relatively rough. The specific structure of the first polishing tool 30 includes: a cylindrical polishing end 31 and a connecting rod 32. The cylindrical polishing end 31 is installed and fixed to the engraving pen through the connecting rod 32. The connecting rod 32 has a certain length to ensure that the distance between the top of the cylindrical polishing end 31 and the top of the engraving pen clamp is greater than the depth H of the groove 13 of the optical component 10, and to ensure that the first polishing tool 30 is installed in place on the engraving pen, and the clamp is about to be locked.

[0082] After turning on the power switch, the operator holds the electric engraving pen with his hand so that the first polishing abrasive on the electric engraving pen is in close contact with the local curved surface of the convex spherical surface, polishes the local curved surface area in the middle of the spherical surface, and rubs the cylindrical polishing end with the convex spherical surface of the optical part. During the polishing process, try to make the polishing auxiliary material mixture fully adhere to the convex spherical surface and the cylindrical polishing end.

[0083] During the polishing process, the first polishing tool can be tilted and contact the local arc surface of the convex spherical surface. In the specific process, if the selected first polishing tool is long enough, it can be tilted with the contact point as the center during the polishing process. The acute angle between the central axis of the first polishing tool and the horizontal plane is the tilt angle α. When the first polishing tool is tilted, the tilt angle α must be greater than the anti-touch angle α. x , where the anti-touch angle α x is the angle between the line connecting the edge of the convex spherical surface to the opening edge of the groove in the corresponding direction and the horizontal plane, where x represents different positions. x When the first polishing tool is polished, it will not collide with the inner wall of the groove during the polishing process, thereby avoiding damage to other surfaces of the optical component and ensuring the quality of the optical component.

[0084] See also Figure 7 In Figure (1), when a convex spherical surface is polished, the anti-touch angle α1 between the convex spherical surface and the inner wall of the groove that is closer to it, the groove depth is H, and the line L1 from the edge point of the convex spherical surface to the opening edge of the groove in the corresponding direction is Sinα1 = H / L1; the anti-touch angle α2 between the convex spherical surface and the inner wall of the groove that is farther away from it, the groove depth is H, and the line L2 from the edge point of the convex spherical surface to the opening edge of the groove in the corresponding direction is Sinα2 = H / L2.

[0085] See also Figure 7 In Figure (2), when polishing another convex spherical surface, the anti-touch angle α3 between the convex spherical surface and the inner wall of the groove that is farther away from it, the groove depth is H, and the line L3 from the edge point of the convex spherical surface to the opening edge of the groove in the corresponding direction, then Sinα3=H / L3; the anti-touch angle α4 between the convex spherical surface and the inner wall of the groove that is closer to it, the groove depth is H, and the line L4 from the edge point of the convex spherical surface to the opening edge of the groove in the corresponding direction, then Sinα4=H / L4.

[0086] During the polishing process, the polishing speed of the first polishing tool is gradually increased until the first rough polishing speed is reached. Initially, the engraving pen speed is adjusted to within 300 rad / min for initial polishing to observe any issues, such as over-polishing. Once the initial polishing is stable, the speed is adjusted to 600 rad / min. This ensures a more stable rough polishing process, improving polishing efficiency while also ensuring quality control and preventing errors that could lead to scrapped optical components.

[0087] During the polishing process using the first rough polishing speed, the tilt angle of the first polishing tool is adjusted within a predetermined range. The adjustment range of the tilt angle is consistent with the anti-touch angle α. x Related, that is, in (90° to α x). Adjust the angle within the range, change the contact point of the first polishing tool within the range of the local curved surface, and rotate the optical part around the center point of the convex spherical surface at any angle from time to time. Thereby, full-surface polishing of the local curved surface is achieved, and the polishing amount is uniform and the polishing speed is fast. In the specific process, during the polishing process, it is necessary to rotate the optical part around the center point at any angle from time to time (at least once within 2 minutes), and the polishing head makes irregular movements relative to the spherical surface. By rotating at irregular angles from time to time and making irregular movements of the polishing head, the polishing trajectory is close to disorder. The disordered polishing process can make the surface polishing more uniform.

[0088] During the rough polishing process, the machine is stopped at predetermined intervals to monitor the polishing agent mixture. When the polishing agent mixture level drops below the top of the convex spherical surface, additional polishing agent mixture is added. During the process, the machine is stopped every 5 minutes to monitor whether the polishing agent mixture is insufficient. If so, additional polishing agent mixture is added to ensure the required polished surface quality.

[0089] During the rough polishing process, the partially polished curved surface is inspected by light at intervals of a second predetermined time to ensure that it meets the rough polishing quality standard. The optical component is cleaned and blown clean with compressed air every 10 minutes, and visually inspected under a dedicated inspection light to prevent excessive local removal. The partially polished curved surface is also inspected to ensure it is polished brightly (free of pinholes) and meets polishing grade P2. If the partially polished curved surface is not brightly polished, the position of the first polishing tool is adjusted to focus polishing on that area until it meets the required quality.

[0090] If there are multiple convex spherical surfaces on the planar substrate, the local arc-shaped surface of each convex spherical surface can be roughly polished in sequence using the above method.

[0091] Step S230: Roughly polishing the partial annular surface of the convex spherical surface by using a second polishing tool, wherein the diameter of the top end of the second polishing tool is smaller than the diameter of the top end of the first polishing tool.

[0092] For details, please refer to Figure 4 、 Figure 6, replace the polishing tool on the engraving pen with a second polishing tool 40. The second polishing tool 40 can use a cotton swab polishing head. The roughness of the cotton swab polishing head is smaller than that of the wool polishing head (first polishing tool 30). The specific structure of the second polishing tool 40 includes: a conical polishing end 41 and a connecting rod 32. The conical polishing end 41 is installed and fixed to the engraving pen through the connecting rod 32. The top of the conical polishing end 41 is a pointed cone structure. During the polishing process of the conical polishing end 41, the tip of the conical polishing end 41 can be abutted against the outer edge of the convex spherical surface 12 for grinding and polishing, so that the local annular surface of the convex sphere can be polished. The second polishing tool 40 can also use a streamlined conical end, which gradually becomes smaller in the direction toward the top and has a pointed cone structure at the top. The installation method, operation steps, precautions and polishing process of using a cotton swab polishing head to polish the local annular surface area of ​​the convex spherical surface are the same as the rough polishing process of the first polishing abrasive tool. Refer to the rough polishing process of the above-mentioned first polishing abrasive tool to complete the rough polishing of the local annular surface through the second polishing abrasive tool.

[0093] If there are multiple convex spherical surfaces on the flat substrate, the above method can be used to sequentially rough-polish the local annular surface of each convex spherical surface. Use clean water to rinse the polishing auxiliary material mixture on the surface of the optical component and prepare for the next step of fine polishing.

[0094] See also Figure 1 In step S300, the convex spherical surface of the front surface of the optical component after rough polishing is finely polished by a third polishing tool and a fourth polishing tool, wherein the third polishing tool is used for fine polishing a local arc surface, and the fourth polishing tool is used for fine polishing a local annular surface.

[0095] For details, please refer to Figure 4 、 Figure 5 、 Figure 6 The convex spherical surface 12 on the front side of the roughly polished optical component 10 is finely polished by the third polishing tool 50 and the fourth polishing tool 60 respectively. The third polishing tool 50 finely polishes the local arc surface that is easy to process, and the fourth polishing tool 60 finely polishes the local annular surface that is not easy to process, thereby achieving fine polishing of the entire surface of the convex spherical surface 12 with a small polishing amount, ensuring that the entire surface of the convex spherical surface 12 meets the high-precision requirements of roughness, surface shape, and polishing grade.

[0096] See also Figure 1 、 Figure 2 Therefore, step S300 specifically includes:

[0097] Step S310: dripping a polishing auxiliary material mixture of a second concentration into the groove on the front surface of the optical component so that the liquid level of the polishing auxiliary material mixture is above the top of the convex spherical surface, wherein the second concentration is higher than the first concentration.

[0098] In a specific process, a second concentration of 0.34 g / ml of cerium oxide with a particle size of 0.7-0.8 μm and pure water is used as the polishing auxiliary liquid mixture. The second concentration is higher than the first concentration of the polishing auxiliary liquid mixture used in the rough polishing process. A higher concentration of the polishing auxiliary liquid mixture improves fine polishing efficiency, shortening the fine polishing process time while achieving the required polishing quality. A rubber-tipped dropper is used to drop the second concentration of the polishing auxiliary liquid mixture into the groove of the optical component so that the polishing auxiliary liquid mixture covers the top of the convex spherical surface.

[0099] Step S320: fine-polishing the local arc-shaped surface after rough polishing by using a third polishing abrasive, wherein the roughness of the third polishing abrasive is less than that of the first polishing abrasive, and gradually increasing the polishing speed of the third polishing abrasive to reach a second fine-polishing speed, which is less than the first rough-polishing speed.

[0100] For details, please refer to Figure 4 、 Figure 5 The third polishing tool 50 can be a sponge polishing head, which has a lower roughness than a wool polishing head. The structure of the third polishing tool 50 can be the same or similar to the shape of the first polishing tool 30. Similarly, the third polishing tool 50 is installed on the engraving pen and ensures that the top of the polishing head is greater than the depth H of the groove 13 of the optical component 10 from the top of the engraving pen clamp. The polishing head is also ensured to be installed in place on the engraving pen, that is, the clamp is locked. After turning on the power switch, hold the electric engraving pen by hand so that the polishing head of the electric engraving pen is in close contact with the local curved surface of the convex ball. Rub the cylindrical polishing end 31 of the third polishing tool 50 against the local curved surface. During the polishing process, try to ensure that the polishing auxiliary material mixture is fully adhered between the local curved surface and the polishing head.

[0101] During the polishing process, gradually increase the polishing speed of the third polishing tool to reach the second fine polishing speed, which is slower than the first rough polishing speed. Specifically, adjust the engraving pen speed to within 300 rad / min for initial polishing to observe if there are any problems. Once these are confirmed, adjust the speed to the second fine polishing speed, which can be 450 rad / min. By gradually increasing the speed and performing fine polishing at a slower speed than the first rough polishing speed, operators gradually adapt to the polishing process, making it more stable and ensuring consistent control of the polishing quality, thus avoiding errors that could lead to the scrapping of optical components.

[0102] Using the first polishing tool as a rough polishing tool, the third polishing tool can also adjust its tilt angle within a predetermined range. During the polishing process, the optical component is rotated around its center point at random angles (at least once every two minutes), and the polishing head of the third polishing tool performs irregular movements relative to the spherical surface. This irregular rotation of the optical component and the irregular movement of the polishing head create a more uniform polishing path, resulting in a more even surface finish.

[0103] During the fine polishing process, the machine is stopped at a predetermined interval to observe the polishing auxiliary material mixture. When the liquid level of the polishing auxiliary material mixture is lower than the top of the convex spherical surface, the polishing auxiliary material mixture is added. Every 5 minutes (the first predetermined time), the machine is stopped to observe whether the polishing auxiliary material mixture is too low. If too low, the polishing auxiliary material mixture needs to be added.

[0104] During the fine polishing process, the finely polished local curved surface is inspected at intervals of a second predetermined time to ensure that the finely polished local curved surface meets the fine polishing quality standard. To prevent excessive local processing, the finely polished local curved surface needs to be cleaned and blown clean with compressed air every 10 minutes (the second predetermined time). A white light interferometer is used to inspect the area within the local curved surface of the spherical surface to see if the spherical surface meets Rq < 80nm. If the local curved surface area does not meet the standard, the next polishing needs to focus on polishing. This process needs to be repeated 3 to 4 times (the actual number depends on the actual situation) to complete the fine polishing of the local curved surface area of ​​the spherical surface.

[0105] Step S330: fine-polishing the partial annular surface of the convex spherical surface by using a fourth polishing tool, wherein the top diameter of the fourth polishing tool is smaller than the top diameter of the third polishing tool.

[0106] For details, please refer to Figure 4 、 Figure 6, replace the polishing tool on the engraving pen with the fourth polishing tool 60. The fourth polishing tool 60 can use a cotton swab polishing head. The roughness of the cotton swab polishing head is smaller than that of the wool polishing head (the first polishing tool 30), and the structure of the fourth polishing tool 60 is the same or similar to that of the second polishing tool 40, so that the top diameter of the fourth polishing tool 60 is smaller than the top diameter of the third polishing tool 50. In the specific structure, the fourth polishing tool 60 also has a conical polishing end 41, and the top of the conical polishing end 41 is a pointed cone structure, or the fourth polishing tool 60 has a streamlined conical end, which gradually becomes smaller in the direction toward the top and has a pointed cone structure at the top. During the polishing process with the conical polishing end 41, the tip of the conical polishing end 41 can be abutted against the outer edge of the convex spherical surface 12 for grinding and polishing, so that the local annular surface of the convex sphere can be finely polished. The installation method, operating steps, precautions, and polishing process for fine polishing a localized annular surface of a convex spherical surface using a cotton swab polishing head are identical to the fine polishing process using the third polishing tool. Reference is made to the fine polishing process of the third polishing tool to complete the fine polishing of the localized annular surface using the fourth polishing tool. The polished surface roughness of the convex spherical surface after fine polishing is Rq < 80nm, the polished surface profile requirement PV < 3.5λ@633nm, and the polishing grade is P2.

[0107] If there are multiple convex spherical surfaces on the flat substrate, the above method can be used to sequentially fine-polish the local annular surfaces of each convex spherical surface. Use clean water to rinse the polishing auxiliary material mixture on the surface of the optical component and prepare for the next step of processing.

[0108] Step S350: The polished optical component with the protective component is sequentially ultrasonically cleaned in different cleaning tanks.

[0109] In the specific process, after the optical parts with protective parts are placed in the cleaning basket, the optical parts with protective parts are placed in the ultrasonic chemical cleaning tank for cleaning through ultrasonic cleaning equipment. Specifically, they are cleaned in the strong alkali tank for 5 minutes, the weak alkali tank for 10 minutes, the water washing tank A for 10 minutes, and the water washing tank B for 5 minutes. Then, the optical parts with protective parts are taken out of the cleaning basket, wiped clean with a dust-free cloth, and placed on the storage tray, ready for the next step of unloading.

[0110] See also Figure 1 , step S400, separating the finely processed optical component from the protective component.

[0111] In a specific process, the hot melt adhesive layer between the protective member and the optical member is melted by heating, thereby separating the optical member from the protective member.

[0112] See also Figure 1 、 Figure 2 Therefore, the specific process of step S400 includes:

[0113] Step S410: Provide a cleaning tray, and place the polished optical component with the protective component into the cleaning tray filled with cleaning liquid.

[0114] See also Figure 8 The cleaning tray 71 can be a small aluminum tray, which is lightweight and has good heat conduction performance. First, place the optical component 10 with the protective member 20 into the small aluminum tray, and then add a cleaning solution of alcohol and acetone in a ratio of 1:1 into the small aluminum tray. The liquid level must be above the optical component 10 with the protective member 20.

[0115] Step S420: heating the cleaning liquid in the cleaning tray to melt the hot melt adhesive layer between the polished optical component and the protective component.

[0116] See also Figure 8 In this step, a heating tray 70 is provided. Heating tray 70 can be a large aluminum tray and contains hot water at a temperature higher than a preset temperature. A cleaning tray 71 containing cleaning fluid and the polished optical component 10 with the protective member 20 is placed in heating tray 70 and allowed to stand for a predetermined period of time.

[0117] In the specific process, hot water is placed in the large aluminum pan, with the liquid level reaching about half the depth of the large aluminum pan and the temperature should be above 70°C. Then the small aluminum pan containing the cleaning liquid and the optical component with the protective part is placed into the large aluminum pan and left to stand for about 5 minutes. The wax layer is heated and softened, thus separating the protective part from the optical component.

[0118] Step S430: remove the polished optical component from the protective component and clean it.

[0119] During the specific process, use special clips to remove the optical components and protective components, wipe them clean with a dust-free cloth, and place them on the storage tray in the same direction, ready for the next step of final inspection.

[0120] Step S500: After the separated optical components are left to stand at room temperature for a predetermined period of time, the optical components are subjected to a final inspection.

[0121] During the specific process, the cleaned product needs to be stabilized at room temperature for 1 hour and then sent to final inspection for final inspection of the optical parts.

[0122] In summary, the present application proposes a polishing method for an optical component with a convex spherical surface. A protective member is disposed on the back of the optical component to support and protect the back of the optical component. The convex spherical surface on the front of the optical component is rough-polished by a first polishing tool and a second polishing tool, respectively. The first polishing tool quickly polishes the easily machined local curved surface, while the second polishing tool quickly polishes the difficultly machined local annular surface. This achieves rough polishing of the entire convex spherical surface, increasing the polishing volume and improving polishing efficiency. The rough-polished convex spherical surface on the front of the optical component is fine-polished by a third polishing tool and a fourth polishing tool. The third polishing tool fine-polishes the easily machined local curved surface, while the fourth polishing tool fine-polishes the difficultly machined local annular surface. This achieves fine polishing of the entire convex spherical surface, reducing the polishing volume and ensuring that the entire surface of the convex spherical surface meets high-precision requirements for roughness, surface shape, and polishing grade. Separating the finely machined optical component from the protective member yields the completed optical component. When this processing scheme is used to polish a spherical surface with a diameter of less than 5 mm on a flat substrate, the second polishing abrasive tool and the fourth polishing abrasive tool can be used to polish the local annular surface that is difficult to process. In addition, the roughness, surface shape, and polishing grade of the optical component can be stably controlled during the polishing process, so that this type of optical component product can meet the technical index requirements.

[0123] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A polishing method for an optical component with a convex spherical surface, characterized in that: The method comprises the steps of: providing a protective member, and setting the protective member on the back side of the optical member; Roughly polishing the convex spherical surface of the front surface of the optical component using a first polishing tool and a second polishing tool, respectively, wherein the convex spherical surface includes a partial arc-shaped surface located in the middle and a partial annular surface located on the outside, the first polishing tool is used for rough polishing the partial arc-shaped surface, and the second polishing tool is used for rough polishing the partial annular surface; The convex spherical surface of the front surface of the optical component after rough polishing is finely polished by a third polishing tool and a fourth polishing tool, respectively, wherein the third polishing tool is used for fine polishing the local arcuate surface, and the fourth polishing tool is used for fine polishing the local annular surface; wherein the structure of the third polishing tool is the same as or similar to the shape of the first polishing tool, and the structure of the fourth polishing tool is the same as or similar to the shape of the second polishing tool; separating the finely processed optical component from the protective component; The step of providing a protective member and placing the protective member on the back of the optical member specifically includes: The protective member includes a protective glass with a gas-proof groove, and the protective glass is heated; Applying a hot melt adhesive layer on the side of the protective glass provided with the air-avoiding groove; The side of the protective glass provided with the avoidance groove is bonded to the back of the optical component through the hot melt adhesive layer, wherein the avoidance groove is used to avoid the coating area on the back of the optical component, and the shape of the avoidance groove corresponds to the shape of the coating area.

2. The polishing method for an optical component with a convex spherical surface according to claim 1, wherein: The steps of respectively rough-polishing the convex spherical surface of the front surface of the optical component by using the first polishing tool and the second polishing tool specifically include: dripping a polishing auxiliary material mixture of a first concentration into the groove on the front surface of the optical component so that the liquid level of the polishing auxiliary material mixture is above the top of the convex spherical surface; Roughly polishing a local arcuate surface of the convex spherical surface by using a first polishing tool, wherein the surface area of ​​the local arcuate surface accounts for a maximum of three quarters of the surface area of ​​the convex spherical surface; The partial annular surface of the convex spherical surface is roughly polished by a second polishing tool, wherein the diameter of the top end of the second polishing tool is smaller than the diameter of the top end of the first polishing tool.

3. The polishing method for an optical component with a convex spherical surface according to claim 2, wherein: In the step of roughly polishing the local arc surface of the convex spherical surface by the first polishing abrasive tool: The first polishing tool is tilted and contacts the local arc surface of the convex spherical surface; gradually increasing the polishing speed of the first polishing abrasive tool to reach a first rough polishing speed; During the polishing process using the first rough polishing speed, the tilt angle of the first polishing tool is adjusted within a predetermined range, and the optical component is rotated around the center point of the convex spherical surface at an arbitrary angle from time to time.

4. The polishing method for an optical component with a convex spherical surface according to claim 3, wherein: In the step of roughly polishing the local arc surface of the convex spherical surface by the first polishing abrasive tool: Stopping the machine at a first predetermined interval to observe the polishing auxiliary material mixture, and adding the polishing auxiliary material mixture when the liquid level of the polishing auxiliary material mixture is lower than the top of the convex spherical surface; The roughly polished partially curved surface is subjected to light inspection at intervals of a second predetermined time to ensure that the roughly polished partially curved surface meets the rough polishing quality standard.

5. The polishing method for an optical component with a convex spherical surface according to claim 3, wherein: In the step of fine-polishing the convex spherical surface of the front surface of the optical component after rough polishing by the third polishing tool and the fourth polishing tool respectively: dripping a polishing auxiliary material mixture of a second concentration into the groove on the front surface of the optical component so that the liquid level of the polishing auxiliary material mixture submerges the top of the convex spherical surface, wherein the second concentration is higher than the first concentration; performing fine polishing on the partially curved surface after rough polishing using a third polishing tool, wherein the roughness of the third polishing tool is less than that of the first polishing tool, and gradually increasing the polishing speed of the third polishing tool to reach a second fine polishing speed, wherein the second fine polishing speed is less than the first rough polishing speed; The partial annular surface of the convex spherical surface is finely polished by a fourth polishing tool, wherein the top diameter of the fourth polishing tool is smaller than the top diameter of the third polishing tool.

6. The polishing method for an optical component with a convex spherical surface according to claim 1, wherein: The steps of separating the finely processed optical component from the protective component specifically include: Providing a cleaning tray, placing the polished optical component with the protective component into the cleaning tray filled with cleaning liquid; The cleaning liquid in the cleaning tray is heated to melt the hot melt adhesive layer between the polished optical component and the protective component; Remove the polished optic from the protector and clean it.

7. The polishing method for an optical component with a convex spherical surface according to claim 1, wherein: In the step of heating the cleaning liquid in the cleaning tray to melt the hot melt adhesive layer between the polished optical component and the protective component: providing a heating pan, wherein hot water is contained in the heating pan, wherein the temperature of the hot water is higher than a preset temperature; The cleaning tray containing the cleaning liquid and the polished optical component with the protective component is placed on the heating tray and left to stand for a predetermined time.

8. The polishing method for an optical component with a convex spherical surface according to claim 1, wherein: The step of applying the hot melt adhesive layer to the heated surface of the protective glass also includes: The polished optical component with the protective component is sequentially ultrasonically cleaned in different cleaning tanks, wherein the different cleaning tanks sequentially include: a strong alkali tank, a weak alkali tank, a first water washing tank, and a second water washing tank.

9. The polishing method for an optical component with a convex spherical surface according to claim 1, wherein: After the step of separating the finely processed optical component from the protective component, the method further comprises: After the separated optical components are left to stand at room temperature for a predetermined period of time, the optical components are subjected to a final inspection.

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