A high-precision low-defect composite polishing disc for ring polishing and a processing method thereof

Abstract

The application discloses a kind of high-precision low-defect annular polishing composite polishing disc and its processing method, composite polishing disc includes: polishing disc base disc, which is provided with pitch layer, groove is opened on the surface of pitch layer, after forming pitch block structure that is covered on its surface, the surface of pitch layer is obtained by using large-size correction disc trimming, and the base surface that the processing optical element surface shape precision meets the requirements is obtained, the pitch layer surface obtained at this time is bonded to damping cloth polishing pad on the corresponding clean pitch block structure, so that damping cloth polishing pad and pitch block structure cooperate to polish optical element.The application uses damping cloth polishing pad to replace pitch layer and directly contact and polish optical element, which can realize defect-free or low-defect processing, and avoid the problem that pitch polishing disc is easy to produce scratch and other defects when directly contacting and polishing optical element.Damping cloth polishing pad is pasted on pitch layer, pitch layer has good flexibility, the concave-convex shape of composite polishing disc or pitch layer is changed by adjusting the radial position of correction disc, and the polishing precision of element is improved.

Description

Technical Field

[0001] This invention relates to the field of optical processing technology, and more specifically to a high-precision, low-defect annular polishing composite polishing disc and its processing method. Background Technology

[0002] Circular polishing (or simply ring polishing) is one of the key technologies for processing large-diameter planar optical components. Circular polishing machines typically use a large-sized, thermally stable natural granite base plate, with a ring-shaped asphalt layer cast on its surface to serve as the polishing disc. A correction disc and a workpiece disc are sequentially placed on the ring surface of the asphalt polishing disc. Gear synchronous belts are installed on the circumferential sides of both the correction and workpiece discs, and both are driven by a pair of gears holding them in place, rotating at a uniform speed. The correction disc is used to correct and control the shape errors of the polishing disc, while the workpiece disc is used to hold the component. During processing, the polishing disc, correction disc, and workpiece disc all rotate at a constant counterclockwise speed. The optical component placed in the workpiece disc undergoes material removal under the action of the asphalt polishing disc and the polishing particles it carries, thus forming the optical surface.

[0003] Because ring polishing uses a large-size asphalt polishing disc, larger than the optical element being processed, and the entire surface of the optical element is in contact with the polishing disc during polishing, ring polishing has significant advantages in suppressing mid-frequency waviness errors, improving processing efficiency, and reducing processing costs. The asphalt polishing disc in ring polishing has good flexibility, and a large-size correction disc is typically used to correct and control the shape error of the asphalt polishing disc. By adjusting the radial position of the correction disc on the surface of the asphalt polishing disc, the concave and convex shape of the polishing disc is changed, thereby achieving high-precision processing of optical elements.

[0004] The polishing pads commonly used in the polishing of optical components include asphalt pads, polyurethane polishing pads, and damping cloth polishing pads. Polyurethane and damping cloth polishing pads have a large number of pores on their surface, which can store coarse particles, thereby greatly reducing the probability of defects.

[0005] The asphalt polishing disc is more brittle than polyurethane and damping cloth. Furthermore, the surface of the asphalt disc gradually becomes smooth during the polishing process, and the surface lacks pores that can store large particles of impurities. This makes the asphalt disc prone to scratches during ring polishing, which poses a significant challenge to the defect control of optical components. In contrast, polyurethane is inferior to damping cloth in terms of defect suppression and deformation flexibility.

[0006] Therefore, how to provide a high-precision, low-defect composite polishing disc for annular polishing and its processing method is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] Therefore, one objective of this invention is to provide a high-precision, low-defect composite polishing disc for annular polishing, addressing the problem that existing asphalt discs gradually become smooth during polishing, lacking pores to store large particles of impurities, thus making defect control of optical components difficult. This invention proposes a composite polishing disc to address the problem of scratches easily generated by asphalt discs in annular polishing.

[0008] Another objective of this invention is to provide a method for processing or manufacturing a high-precision, low-defect circular polishing composite polishing disc.

[0009] This invention provides a high-precision, low-defect annular polishing composite polishing disc, comprising: a polishing disc base, on which an asphalt layer is disposed, and grooves are formed on the surface of the asphalt layer to form an asphalt block structure covering its surface. A large-size correction disc is used to trim the surface of the asphalt layer to obtain a base surface that meets the required surface shape accuracy for processing optical components. A damping cloth polishing pad is then bonded to the clean asphalt block structure on the surface of the asphalt layer obtained at this time, so that the damping cloth polishing pad and the asphalt block structure work together to polish the optical components.

[0010] Furthermore, the formed asphalt block structures are arranged at equal intervals.

[0011] Furthermore, the shape of the damping cloth polishing pad is adapted to the shape of the asphalt block structure.

[0012] Furthermore, the asphalt block structure is a grid.

[0013] Furthermore, the back of the damping cloth polishing pad has an adhesive backing layer.

[0014] Furthermore, the asphalt layer is poured onto the polishing disc base.

[0015] Furthermore, the thickness of the asphalt layer is 10-30 mm, and the thickness of the damping cloth polishing pad 13 is 0.5-3 mm.

[0016] Furthermore, the depth of the trench is 4-10 mm.

[0017] Furthermore, the spacing between adjacent asphalt block structures is 50-300 mm.

[0018] This invention also provides a method for processing a high-precision, low-defect annular polishing composite polishing disc, comprising the following steps:

[0019] A layer of asphalt is poured onto the surface of the polishing disc base. After the surface of the asphalt layer is milled flat, grooves are milled to form, and asphalt block structures covering the surface are formed between adjacent grooves.

[0020] Then, the ring polishing machine is run to process the optical components. During processing, the large-size correction disc of the ring polishing machine is placed on the surface of the asphalt layer. The radial position of the correction disc is adjusted to change the uneven shape of the asphalt layer surface until the surface accuracy of the optical components meets the requirements. At this time, the surface of the asphalt layer has a low shape error. Then, the ring polishing machine is stopped and the surface of the asphalt layer is cleaned.

[0021] Cut a damping cloth polishing pad to match the shape and size of the asphalt block structure, and then bond the damping cloth polishing pad to the cleaned surface of the asphalt block structure to form a composite polishing disc in which the asphalt layer and the damping cloth polishing pad work together.

[0022] As can be seen from the above technical solution, compared with the prior art, the present invention uses a damping cloth polishing pad to replace the asphalt layer for direct contact and polishing of optical components, which can achieve defect-free or low-defect processing and avoid the problem of scratches and other defects that are easily generated when the asphalt polishing pad directly contacts and polishes optical components. At the same time, the damping cloth polishing pad is pasted on the asphalt layer, and the asphalt layer has good flexibility, so the concave and convex shape of the composite polishing pad or the asphalt layer can be changed by adjusting the radial position of the correction pad, thereby improving the polishing accuracy of the components. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This invention provides a structural schematic diagram of a high-precision, low-defect annular polishing composite polishing disc.

[0025] Figure 2 A schematic diagram of a partial cross-section of a high-precision, low-defect annular polishing composite polishing disk.

[0026] Figure 3 This illustration shows a ring polisher using a high-precision, low-defect ring polishing composite polishing disc provided by the present invention. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] Because the asphalt polishing disc of a ring polishing machine has good flexibility, a large-size correction disc is usually used to correct and control the shape error of the asphalt polishing disc. By adjusting the radial position of the correction disc on the surface of the asphalt polishing disc, the concave and convex shape of the polishing disc is changed, thereby achieving high-precision processing of optical components. Therefore, the asphalt polishing disc plays an important role in the processing of optical components. However, during the polishing process, the surface of the asphalt disc gradually becomes smooth, and the surface lacks pores that can store large particles of impurities, which makes the asphalt disc prone to scratches during ring polishing, making it difficult to control defects in optical components.

[0029] Therefore, this invention discloses a high-precision, low-defect annular polishing composite polishing disk, see appendix. Figure 1 and 2 The process includes: a polishing base plate 11, on which an asphalt layer 12 is provided. Grooves are opened on the surface of the asphalt layer 12 to form an asphalt block structure covering its surface. A large-size correction plate is used to trim the surface of the asphalt layer 12 to obtain a base surface that meets the required surface shape accuracy for the optical element 3. At this time, a damping cloth polishing pad 13 is bonded to the clean asphalt block structure on the surface of the asphalt layer 12, so that the damping cloth polishing pad 13 and the asphalt block structure work together to polish the optical element 3.

[0030] In the description of this invention, "the surface of the asphalt layer 12 is modified to obtain a base surface that meets the surface accuracy requirements of the optical element 3" means that after the asphalt block structure is formed, the surface of the asphalt layer is modified first. The modification method is to use a polishing machine to process the optical element 3. During processing, the large-size correction disk 21 of the ring polishing machine is placed on the surface of the asphalt layer 12. The concave and convex shapes of the surface of the asphalt layer 12 are changed by adjusting the radial position of the correction disk 21 until the surface PV value of the optical element 3 is better than 0.5μm. At this time, the surface of the asphalt layer 12 has a low shape error, which meets the surface accuracy requirements of the optical element 3.

[0031] In the description of this invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] In embodiments of the present invention, a damping cloth polishing pad is used instead of an asphalt layer to directly contact and polish optical components. This enables defect-free or low-defect processing of optical components, avoiding the scratches and other defects that easily occur when an asphalt polishing pad directly contacts and polishes optical components. Simultaneously, the damping cloth polishing pad is adhered to the asphalt layer, which has good flexibility. This allows the radial position of the correction pad to be adjusted to change the uneven shape of the composite polishing pad or the asphalt layer, improving the polishing accuracy of the components. Furthermore, the surface of the damping cloth can store particles, significantly reducing the probability of defects in the optical components and further improving the polishing accuracy.

[0033] In an embodiment of the present invention, the asphalt block structures are arranged at equal intervals. The grooves around the asphalt block structures can be generated using the milling mechanism of the ring polisher 2, thus forming the asphalt block structures.

[0034] In embodiments of the present invention, the contact surface between each of the asphalt block structures and the damping cloth polishing pad 13 is set flat and kept clean.

[0035] The shape of the damping cloth polishing pad 13 is adapted to the shape of the asphalt block structure. It can be circular, square, arc, fan-shaped, or other common shapes, or even irregular shapes.

[0036] In an embodiment of the present invention, the asphalt block structure is generated by the milling mechanism of the ring polisher 2. Preferably, the asphalt block structure adopts a grid pattern.

[0037] In a specific embodiment of the present invention, the damping cloth polishing pad 13 is bonded to the top surface of the asphalt block structure. The bonding method can be adhesive backing, glue, or other similar methods. In this embodiment, the damping cloth polishing pad has an adhesive backing for easy bonding.

[0038] In the above embodiments, the asphalt layer 12 is cast onto the polishing disc base 11. The thickness of the asphalt layer 12 is 10-30 mm, the thickness of the damping cloth polishing pad 13 is 0.5-3 mm, and the depth of the groove is 4-10 mm (excluding the thickness of the damping cloth polishing pad).

[0039] Advantageously, the spacing between adjacent asphalt block structures is 50-300 mm.

[0040] The processing or manufacturing method of the high-precision, low-defect annular polishing composite polishing disc of the present invention is as follows:

[0041] A layer of asphalt is poured onto the surface of the polishing disc base. After the surface of the asphalt layer is milled flat, grooves are milled to form, and asphalt block structures covering the surface are formed between adjacent grooves.

[0042] Then, the ring polishing machine is run to process the optical components. During processing, the large-size correction disc of the ring polishing machine is placed on the surface of the asphalt layer. The radial position of the correction disc is adjusted to change the uneven shape of the asphalt layer surface until the surface accuracy of the optical components meets the requirements. At this time, the surface of the asphalt layer has a low shape error. Then, the ring polishing machine is stopped and the surface of the asphalt layer is cleaned.

[0043] Cut a damping cloth polishing pad to match the shape and size of the asphalt block structure, and then bond the damping cloth polishing pad to the cleaned surface of the asphalt block structure to form a composite polishing disc in which the asphalt layer and the damping cloth polishing pad work together.

[0044] To illustrate the present invention in more detail, the following specific embodiments are provided, such as... Figure 1 and Figure 2 As shown, the composite polishing disc 1 has a diameter of 4m and a polishing disc base 11 with a thickness of 280mm. An annular asphalt layer 12 with a thickness of 20mm is poured onto the polishing disc base 11, and its inner and outer diameters are 600mm and 2m, respectively. After the annular asphalt layer 12 is poured, the milling mechanism of the ring polishing machine 2 is used to mill the asphalt layer 12 flat and groove it to generate a uniformly distributed grid. The width and depth of the grooves are 10mm and 6mm, respectively, and the spacing is 100mm. The side length of the resulting grid (i.e., the asphalt block structure) is 90mm. Then, the ring polisher 2 is run to process the optical element 3. During processing, the large-size correction disk 21 of the ring polisher 2 is placed on the surface of the asphalt layer 12. The radial position of the correction disk 21 is adjusted to change the uneven shape of the asphalt layer surface 12 until the surface shape PV value of the optical element 3 is better than 0.5μm. At this time, the surface of the asphalt layer 12 has a low shape error. Then, the ring polisher 2 is stopped, the surface of the asphalt layer 12 is cleaned, and the damping cloth polishing pad 13 is attached to its surface.

[0045] After the asphalt layer 12 is milled to form a grid, its surface is divided into multiple grids. The damping cloth polishing pad 13 with adhesive backing is cut into blocks with the same size as the asphalt grid. Then, the damping cloth polishing pad blocks are pasted onto the asphalt grid surface in sequence to form a composite polishing disc 1.

[0046] See appendix Figure 3 When using the composite polishing disc 1 for ring polishing, the optical element 3 is placed on the surface of the composite polishing disc 1 and is held and driven by the workpiece disc 22 to rotate. The large-size correction disc 21 of the ring polishing machine 2 is placed on the surface of the composite polishing disc 1. By adjusting the radial position of the correction disc 21, the concave and convex shape of the composite polishing disc 1 or the asphalt layer 11 is changed, so as to achieve high-precision and low-defect processing of the optical element 3.

[0047] Advantageously, when pouring the asphalt layer 12 onto the polishing pad base 11, asphalt adhesive barriers (outer and inner barriers) with a height of approximately 40 mm are first set on the outer circumference and the inner circumference at a radius of 600 mm on the surface of the polishing pad base 11. The calculated amount of solid asphalt adhesive is heated and melted into liquid asphalt adhesive, which is then poured between the outer and inner barriers on the surface of the polishing pad base 11. After the liquid asphalt adhesive cools, a solid asphalt layer 12 with a certain thickness is formed. The thickness of the asphalt layer is approximately 20 mm; the thickness of the damping cloth polishing pad is approximately 1.3 mm.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for processing a high-precision, low-defect annular polishing composite polishing disc, characterized in that, Includes the following steps: A layer of asphalt is poured onto the surface of the polishing disc base. After the surface of the asphalt layer is milled flat, grooves are milled to form, and asphalt block structures covering the surface are formed between adjacent grooves. Then, the ring polishing machine is run to process the optical components. During processing, the large-size correction disc of the ring polishing machine is placed on the surface of the asphalt layer. The radial position of the correction disc is adjusted to change the uneven shape of the asphalt layer surface until the surface accuracy of the optical components meets the requirements. At this time, the surface of the asphalt layer has a low shape error. Then, the ring polishing machine is stopped and the surface of the asphalt layer is cleaned. Cut a damping cloth polishing pad to match the shape and size of the asphalt block structure, and then bond the damping cloth polishing pad to the cleaned surface of the asphalt block structure to form a composite polishing disc in which the asphalt layer and the damping cloth polishing pad work together. When using a composite polishing disc for ring polishing, the optical element is placed on the surface of the composite polishing disc, and is held and driven to rotate by the workpiece disc. The large-size correction disc that comes with the ring polisher is placed on the surface of the composite polishing disc. By adjusting the radial position of the correction disc, the concave and convex shape of the composite polishing disc or the asphalt layer is changed, so as to achieve high-precision and low-defect processing of the optical element.

2. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 1, characterized in that, The resulting asphalt block structures are arranged at equal intervals.

3. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 1, characterized in that, The shape of the damping cloth polishing pad is adapted to the shape of the asphalt block structure.

4. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 3, characterized in that, The asphalt block structure is a grid.

5. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 1, characterized in that, The back of the damping cloth polishing pad has an adhesive layer.

6. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 1, characterized in that, The asphalt layer is poured onto the polishing disc base.

7. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 1, characterized in that, The thickness of the asphalt layer is 10-30mm, and the thickness of the damping cloth polishing pad is 0.5-3mm.

8. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 7, characterized in that, The depth of the trench is 4-10 mm.

9. The processing method of a high-precision, low-defect annular polishing composite polishing disc according to claim 2, characterized in that, The spacing between adjacent asphalt block structures is 50-300mm.

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