Polishing equipment and its control methods and devices

Abstract

This invention proposes a polishing device and its control method and control apparatus. The polishing device is used for polishing optical materials and includes a spindle, a polishing assembly, and a photosensitive assembly. The spindle is equipped with a turntable coaxially rotatably connected to the spindle. At least one connecting frame is circumferentially protruding from the spindle, and each connecting frame is provided with a clamping cover. The turntable is provided with at least one clamping bottom. Each clamping cover and a clamping bottom are arranged opposite to each other and limit the clamping space. Each clamping space contains stacked optical materials. The corresponding clamping covers and clamping bottoms have a direction of movement that moves closer or further away from each other. The photosensitive assembly includes at least one pair of emitting ends and receiving ends. One of the oppositely arranged clamping covers and clamping bottoms is provided with an emitting end, and the other is provided with a receiving end. A detection optical path is formed between each emitting end and the corresponding receiving end. Each detection optical path is located within the corresponding clamping space, which optimizes the detection steps and improves detection efficiency and detection effect.

Description

Technical Field

[0001] This invention belongs to the field of polishing equipment technology, and particularly relates to a polishing device and its control method and control device. Background Technology

[0002] Polishing optical materials such as wafers, glass, and sapphire can effectively reduce the surface roughness of optical materials, achieving nanoscale smoothness, thereby reducing light absorption and scattering losses on the surface and improving the overall efficiency of the optical system.

[0003] To improve efficiency during polishing, multiple layers of optical materials need to be clamped and polished simultaneously. However, excessive pressure can cause the optical materials to bend or crack. In related technologies, the clamping device places the pressure sensor between the clamping surface and the surface of the optical material. This pressure sensor further compresses the optical material, interfering with the measurement results, leading to large data errors, or even damage to the optical material. Summary of the Invention

[0004] The technical objective of this invention is to provide a polishing device and its control method and control apparatus, which aims to solve the problem of large pressure detection errors that easily damage optical materials.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows: a polishing device for polishing optical materials, comprising:

[0006] The main shaft is equipped with a turntable that is coaxially rotatably connected to the main shaft. The main shaft has at least one connecting frame protruding in its circumference. Each connecting frame is provided with a clamping cover. The turntable has at least one clamping bottom protruding. Each clamping cover and a clamping bottom are arranged opposite to each other and limit the clamping space. Each clamping space is provided with stacked optical materials. The corresponding clamping cover and clamping bottom have a direction of movement that moves closer or further away from each other.

[0007] A polishing assembly is disposed on the rotation trajectory of each of the connecting frames. The two opposing surfaces of the stacked optical materials that contact the clamping cover and the clamping base are pressure surfaces. The side peripheral surface of the optical materials is a polishing surface and is disposed perpendicular to the pressure surface. The polishing assembly has a movement direction that is close to or away from the polishing surface in order to polish the optical materials.

[0008] A photosensitive component includes at least one pair of emitting ends and receiving ends. One of the clamping cover and the clamping base, which are disposed opposite to each other, is provided with one of the emitting ends and the other is provided with one of the receiving ends. A detection optical path is formed between each of the emitting ends and the corresponding receiving ends, and each detection optical path is located within the corresponding clamping space.

[0009] In some embodiments of the present invention, each of the clamping cover members and each of the clamping bottom members are provided with light-transmitting holes, a first connecting tube is provided between each clamping cover member and the corresponding connecting frame, a second connecting tube is provided between each clamping bottom member and the turntable, the inner cavities of each first connecting tube and each second connecting tube are in communication with each of the light-transmitting holes, each first connecting tube is provided with an ejector end, and each second connecting tube is provided with a receiver end.

[0010] In some embodiments of the present invention, the polishing assembly includes a first polishing structure and a second polishing structure arranged at intervals along an annular pattern. The first polishing structure includes a first brush member rotatably connected to the first polishing structure, and the second polishing structure includes a second brush member rotatably connected to the second polishing structure. The first brush member and the second brush member rotate in different directions. Each of the clamping cover members is rotatably connected to the corresponding connecting frame, and each of the clamping bottom members is rotatably connected to the turntable.

[0011] In some embodiments of the present invention, the first polishing structure further includes a lifting shaft and a telescopic shaft, both of which are used to drive the first brush to move closer to or away from the polishing surface. The driving direction of the lifting shaft is perpendicular to the pressure surface, and the driving direction of the telescopic shaft is perpendicular to the polishing surface.

[0012] The first brush component includes a first brush head and a second brush head spaced apart. The first brush head and the second brush head have rotation directions that are inclined or parallel to each other, so that the rotation axis of the first brush head or the second brush head has an angle A with the polishing surface, and the angle A is 10~90°.

[0013] In some embodiments of the present invention, the second polishing structure further includes a first track and a second track, the first track being perpendicular to the second track, and the second brush member including a third brush head and a fourth brush head, the third brush head and the fourth brush head being assembled on the first track such that the third brush head and the fourth brush head have a movement trajectory that moves closer to or further away from each other.

[0014] In some embodiments of the present invention, the polishing apparatus further includes a loading structure comprising a loading platform and at least two positioning baffles mounted on the loading platform, the loading platform having a movement direction toward or away from any of the clamping bases, and at least one of the positioning baffles abutting adjacent polishing surfaces of the optical material.

[0015] The present invention also proposes a control method for controlling the polishing equipment described above, the steps of which include:

[0016] Acquire an initial interference fringe image when the optical material is not in contact with the clamping cover;

[0017] Acquire a real-time interference fringe image when the optical material is in contact with the clamping cover;

[0018] Calculate the contact pressure of the optical material;

[0019] Determine whether the contact pressure is within a preset stress range;

[0020] If the contact pressure is not within the preset pressure range, adjust the distance between the clamping cover and the clamping base.

[0021] In some embodiments of the present invention, the formula for calculating the contact pressure of the optical material is as follows:

[0022] ;

[0023] Where m is the number of moving fringes, obtained by comparing the initial interference fringe image and the real-time interference fringe image, and λ is the wavelength of the light. The refractive index of the optical material is... Where is the refractive index of the air layer, P is the contact pressure, and E is the Young's modulus of the optical material.

[0024] In some embodiments of the present invention, prior to the step of calculating the contact stress of the optical material, the method includes:

[0025] Obtain the initial temperature and real-time temperature of the optical material;

[0026] Calculate the optical path difference due to pressure change of the optical material, wherein the optical path difference due to pressure change is the difference between the total optical path difference of the optical material and the optical path difference due to temperature change of the optical material;

[0027] The calculation formula is:

[0028] ;

[0029] ;

[0030] =2 (k- )p;

[0031] in, The total optical path difference, The optical path difference due to the temperature change. The pressure change represents the temperature difference, α is the coefficient of thermal expansion of the optical material, β is the coefficient of refractive index change of the optical material, and ΔT is the temperature change value of the optical material, where the temperature change value is the difference between the real-time temperature and the initial temperature. The initial thickness of the optical material. Where k is the refractive index of the optical material, and k is the stress-optical coefficient of the optical material;

[0032] The formula for calculating the contact stress of the optical material is as follows: .

[0033] This invention proposes a control device for implementing the control method described above, the control device comprising:

[0034] The first acquisition module is used to acquire the initial interference fringe position when the optical material is not in contact with the clamping cover;

[0035] The second acquisition module is used to acquire the real-time interference fringe position when the optical material is in contact with the clamping cover.

[0036] A calculation module is used to calculate the contact pressure of the optical material;

[0037] The judgment module is used to determine whether the contact pressure is within a preset stress range;

[0038] The adjustment module is used to adjust the distance between the clamping cover and the clamping base if the contact pressure is not within the preset pressure range.

[0039] Compared with the prior art, the polishing equipment, control method, and control device of this invention have the following advantages:

[0040] This invention proposes a polishing device, its control method, and a control apparatus. The polishing device is used for polishing optical materials and includes a spindle, a polishing assembly, and a photosensitive assembly. The spindle is equipped with a turntable coaxially rotatably connected to it. At least one connecting frame is circumferentially protruding from the spindle, and each connecting frame is provided with a clamping cover. The turntable is protruding with at least one clamping bottom. Each clamping cover and a clamping bottom are oppositely arranged and limit a clamping space. Stacked optical materials are arranged in each clamping space. The corresponding clamping covers and clamping bottoms have the ability to move closer or further apart. The movement direction; the polishing assembly is located on the rotation trajectory of each connecting frame, the contact surface between the optical material and the clamping cover and clamping base is the pressure surface, the side peripheral surface of the optical material is the polishing surface and is set perpendicular to the pressure surface, the polishing assembly has a movement direction that is close to or away from the polishing surface, so as to achieve polishing of the optical material; the photosensitive assembly includes at least one pair of emitting end and receiving end, one of the clamping cover and clamping base arranged opposite to each other is provided with an emitting end, and the other is provided with a receiving end, and a detection optical path is formed between each emitting end and the corresponding receiving end, and each detection optical path is located in the corresponding clamping space.

[0041] Each clamping space contains stacked optical materials, and the corresponding clamping cover and clamping base have directions of movement that move closer or further apart from each other. This allows for the simultaneous processing of multiple layers of optical materials, improving the equipment's processing capacity and production efficiency, making it suitable for large-scale production. The movement of the clamping cover is controlled by electrical signal feedback from the photosensitive component, thereby adjusting the size of the clamping space. This solves the problem of interference caused by pressure sensors on the contact surface between the clamping cover and the optical material, eliminating errors, optimizing the detection process, and improving detection efficiency and results. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the overall structure of the polishing equipment in one embodiment of the present invention;

[0043] Figure 2 yes Figure 1 Top view of the polishing equipment;

[0044] Figure 3 yes Figure 1 A schematic diagram of the part of the polishing equipment equipped with optical materials;

[0045] Figure 4 yes Figure 1 Cross-sectional view of optical materials assembled in the clamping space;

[0046] Figure 5 yes Figure 1 A schematic diagram of the loading structure of the polishing equipment;

[0047] Figure 6 yes Figure 1 A schematic diagram of the first polishing structure of the medium-sized polishing equipment;

[0048] Figure 7 yes Figure 6 A schematic diagram of the first polishing structure from another perspective;

[0049] Figure 8 yes Figure 1 A schematic diagram of the second polishing structure of the intermediate polishing equipment;

[0050] Figure 9 This is a flowchart illustrating the control method of the polishing equipment in Embodiment 1 of the present invention;

[0051] Figure 10 This is a flowchart illustrating the control method of the polishing equipment in Embodiment 2 of the present invention.

[0052] In the accompanying drawings, the reference numerals indicate:

[0053] 100. Polishing equipment; 11. Spindle; 111. Turntable; 112. Connecting frame; 113. Clamping cover; 114. Clamping base; 115. Light-transmitting hole; 116. First connecting pipe; 117. Second connecting pipe; 118. Slip ring; 12. First polishing structure; 121. First brush head; 122. Second brush head; 123. Lifting shaft; 124. Telescopic shaft; 125. Telescopic cover; 13. Second polishing structure; 131. First track; 132. Second track; 133. Third brush head; 134. Fourth brush head; 14. Positioning baffle; 15. Loading platform; 161. Injection end; 162. Receiving end; 400. Optical material; 41. Pressure surface; 42. Polishing surface; Detailed Implementation

[0054] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0055] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "circumferential," and "radial," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] Please refer to Figures 1 to 8This invention proposes a polishing device 100 for polishing optical materials 400, including a main spindle 11, a polishing assembly, and a photosensitive assembly. The main spindle 11 is equipped with a turntable 111 coaxially rotatably connected to the main spindle 11. At least one connecting frame 112 is circumferentially protruding from the main spindle 11. Each connecting frame 112 is provided with a clamping cover 113. The turntable 111 is provided with at least one clamping bottom 114. Each clamping cover 113 and a clamping bottom 114 are oppositely arranged and limit a clamping space. Stacked optical materials 400 are arranged in each clamping space. The corresponding clamping cover 113 and clamping bottom 114 have directions of movement that move closer or further away from each other. The polishing assembly is located on each connecting frame 111. On the rotation trajectory of 12, the two opposing surfaces of the stacked optical material 400 that contact the clamping cover 113 and the clamping base 114 are pressure surfaces 41, and the side peripheral surface of the optical material 400 is a polishing surface 42 and is arranged perpendicular to the pressure surface 41. The polishing assembly has a movement direction that is close to or away from the polishing surface 42 to achieve polishing of the optical material 400. The photosensitive assembly includes at least one pair of emitting ends 161 and receiving ends 162. One of the clamping cover 113 and the clamping base 114 arranged opposite to each other is provided with an emitting end 161 and the other is provided with a receiving end 162. A detection optical path is formed between each emitting end 161 and the corresponding receiving end 162, and each detection optical path is located in the corresponding clamping space.

[0058] Optical material 400 is placed in the clamping space and clamped by clamping cover 113 and clamping base 114. The process of assembling, polishing and removing optical material 400 is realized by rotating turntable 111. During the process, the polishing component will approach the optical material 400 for polishing and then move away from the optical material 400 to avoid it. This effectively realizes the high degree of process of polishing equipment 100, improves the degree of automation, and the operator does not need to actively adjust the position of optical material 400, thus improving polishing efficiency and polishing accuracy.

[0059] Each clamping space is provided with stacked optical materials 400, and the corresponding clamping cover 113 and clamping base 114 have a direction of movement that moves closer or further away from each other, thereby enabling the simultaneous processing of multiple layers of optical materials 400, improving the processing capacity and production efficiency of the equipment, and making it suitable for large-scale production.

[0060] An emission end 161, positioned between the connecting frame 112 and the turntable 111, emits light that passes through the stacked optical material 400. The transmitted light signal is received and recorded by the receiving end 162. The optical material 400 deforms under pressure, altering its optical properties. Pressure changes the electron cloud density and relative positions of atoms, resulting in a change in refractive index. This deflection of the incident light beam affects its path and speed within the material. The receiving end 162 calculates the pressure on the optical material 400 by receiving different light signals and feeds this pressure back to the drive mechanism of the clamping cover 113. This precise control of the pressure applied to the optical material 400 prevents damage from excessive pressure within the clamping space, improving the control accuracy of the polishing equipment 100 and the integrity of the optical material 400.

[0061] For special optical materials 400, such as quartz crystals, optical materials 400 will exhibit optomechanical effects, such as piezoelectric effect and photochromic effect. Photochromic effect refers to the change in the lattice structure or charge distribution of a material after it is exposed to light, resulting in a color change within the visible spectrum. The receiver 162 can also analyze pressure by detecting differences in the spectral diagram, achieving accurate pressure data detection.

[0062] Please refer to Figure 3 and Figure 4 In this embodiment, each clamping cover 113 and each clamping base 114 is provided with a light-transmitting hole 115. A first connecting tube 116 is provided between each clamping cover 113 and the corresponding connecting frame 112, and a second connecting tube 117 is provided between each clamping base 114 and the turntable 111. The inner cavity of each first connecting tube 116 and each second connecting tube 117 is connected to each light-transmitting hole 115. Each first connecting tube 116 is provided with an ejector end 161, and each second connecting tube 117 is provided with a receiver end 162.

[0063] The first connecting tube 116 and the second connecting tube 117 provide a stable optical path, avoiding external interference to the light beam during transmission and enhancing detection accuracy and stability. The light-guiding properties of the optical material 400 allow the light beam to pass directly through the optical material 400, achieving precise optical detection. This ensures real-time monitoring of the state of the optical material 400 during polishing, such as its thickness and position. It also enables the photosensitive component to simultaneously monitor and process multiple layers of optical material 400, improving the equipment's processing efficiency and production capacity.

[0064] Please refer to Figure 1 and Figure 2In this embodiment, the polishing assembly includes a first polishing structure 12 and a second polishing structure 13 arranged at intervals along a ring pattern. The first polishing structure 12 includes a first brush member rotatably connected to it, and the second polishing structure 13 includes a second brush member rotatably connected to it. The first brush member and the second brush member rotate in different directions. Each clamping cover 113 is rotatably connected to the corresponding connecting frame 112, and each clamping bottom 114 is rotatably connected to the turntable 111.

[0065] The first and second brushes rotate in different directions and are arranged alternately on a circular pattern. This design ensures that the surface of the optical material 400 is polished from different directions, reducing the unevenness caused by polishing in one direction and guaranteeing the consistency of the polishing effect and surface smoothness. It also reduces stress concentration that may be caused by polishing in one direction, reduces material damage and deformation, and extends the service life of the optical material 400.

[0066] By arranging multiple polishing structures at intervals along a circular pattern, the material can be polished multiple times in a single rotation, improving polishing efficiency and reducing the polishing time for each piece of optical material 400, making it suitable for mass production needs. Furthermore, the different designs of the first polishing structure 12 and the second polishing structure 13 provide different polishing intensities and effects, allowing for more flexible handling of complex-shaped optical materials 400 and better adapting to various complex-shaped optical material 400 surfaces, providing a more uniform and high-quality polishing effect.

[0067] Please refer to Figure 6 and Figure 7 Specifically, the first polishing structure 12 also includes a lifting shaft 123 and a telescopic shaft 124. Both the lifting shaft 123 and the telescopic shaft 124 are used to drive the first brush to approach or move away from the polishing surface 42. The driving direction of the lifting shaft 123 is perpendicular to the pressure surface 41, and the driving direction of the telescopic shaft 124 is perpendicular to the polishing surface 42.

[0068] When the polishing equipment 100 is placed on a plane parallel to the ground, the lifting shaft 123 and the telescopic shaft 124 drive the first brush to move closer to or further away from the polishing surface 42, respectively. Their driving directions are perpendicular to the pressure surface 41 and the polishing surface 42, respectively. That is, the lifting shaft 123 drives the first brush head 121 to move along the height direction of the stacked optical materials 400, and the telescopic shaft 124 drives the first brush head 121 to move along the plane direction of the stacked optical materials 400. This achieves precise control of the depth and force during the polishing process, ensuring that each polishing achieves the expected effect, while avoiding material damage caused by over-polishing.

[0069] The first brush component includes a first brush head 121 and a second brush head 122 spaced apart. The first brush head 121 and the second brush head 122 have rotation directions that are inclined or parallel to each other, so that the rotation axis of the first brush head 121 or the second brush head 122 forms an angle A with the polishing surface 42. The angle A is 10~90°, for example, the angle A can be 20°, 40°, 60°, 80°, etc.

[0070] The rotation direction of the first brush head 121 can be tilted or parallel to each other, and the included angle A can be adjusted. This flexible configuration allows the device to adapt to optical materials 400 of different shapes, sizes, and materials. By adjusting the included angle A, different polishing effects can be achieved to meet diverse polishing needs. This tilting configuration allows the brush head to cover a larger surface area during the polishing process, improving the uniformity of the polishing effect and surface quality, especially for handling complex shapes and details.

[0071] Furthermore, a retractable cover 125 is provided between the first brush head 121 and the second brush head 122. When the first brush head 121 and the second brush head 122 tilt and rotate relative to each other, the retractable cover 125 restricts the relative distance between the first brush head 121 and the second brush head 122, and limits them to the connecting edges of the two adjacent polishing surfaces 42, so as to accurately polish each edge of the optical material 400.

[0072] Please refer to Figure 8 The second polishing structure 13 also includes a first track 131 and a second track 132. The first track 131 and the second track 132 are perpendicular to each other. The second brush includes a third brush head 133 and a fourth brush head 134. The third brush head 133 and the fourth brush head 134 are assembled on the first track 131 so that the third brush head 133 and the fourth brush head 134 have a movement trajectory that moves closer or further away from each other. That is, the third brush head 133 and the fourth brush head 134 move in opposite directions along the plane direction of the optical material 400 on the first track 131. The third brush head 133 and the fourth brush head 134 respectively contact the two opposite polishing surfaces 42 of the optical material 400.

[0073] The second track 132 includes two sub-tracks mounted on the first track 131. The third brush head 133 and the fourth brush head 134 are slidably mounted on the sub-tracks. The extension direction of the sub-tracks is along the height direction of the optical material 400. Combined with the first track 131, the third brush head 133 and the fourth brush head 134 can achieve precise contact with multiple polishing surfaces 42 of the optical material 400. The first track 131 is used to adapt to optical materials 400 of different shapes and sizes, thereby improving the applicability of the polishing equipment 100.

[0074] In this embodiment, both the clamping base 114 and the clamping cover 113 can be connected to a power source, allowing the optical material 400 clamped within the clamping space to rotate. Combined with the polishing assembly, this effectively improves the cleaning effect and efficiency of the polishing equipment 100 on the optical material 400. The first brush is used to polish the edges of the stacked optical material 400, and the second brush is used to polish the entire surface of the stacked optical material 400. These two brushes work together sequentially to achieve precise polishing of the polished surfaces 42 in all circumferential directions of the optical material 400, ensuring a good polishing effect.

[0075] The lifting shaft 123 and the telescopic shaft 124 of the first brush can both be powered by servo motors. The power source that drives the first brush head 121, the second brush head 122, the third brush head 133 and the fourth brush head 134 to rotate can also be a servo motor.

[0076] The power source for controlling the movement of the third brush head 133 and the fourth brush head 134 in the first track 131 and the second track 132 in the second brush component can be a swing motor. The two swing motors drive the two sub-tracks of the second track 132 to move on the first track 131. At the same time, each swing motor can realize the up and down movement of the third brush head 133 and the fourth brush head 134 on the corresponding sub-track of the second track 132 through a crank-connecting rod swing mechanism. When the crank in the crank-connecting rod swing mechanism is subjected to rotational force, the connecting rod head will generate reciprocating linear motion, thereby pushing the corresponding brush head to move on the sub-track.

[0077] Please refer to Figure 5 In this embodiment, the polishing equipment 100 further includes a loading structure, which includes a loading platform 15 and at least two positioning baffles 14 mounted on the loading platform 15. The loading platform 15 has a movement direction that is close to or away from any clamping base 114, and at least one positioning baffle 14 abuts against two adjacent polishing surfaces 42 of the optical material 400.

[0078] The positioning baffle 14 can quickly align the stacked optical materials 400, and at least two positioning baffles 14 are set to achieve precise alignment of the optical materials 400 in the simplest structure, increasing the clearance space and facilitating the loading and unloading of the optical materials 400. The positioning baffle 14 can be made telescopic, and by changing the length of the positioning baffle 14, it can accommodate different layers of optical materials 400.

[0079] Specifically, the power source for driving the clamping cover 113 to move and the power source for controlling the loading platform 15 to move can both be air pumps. A slip ring 118 can be fitted between the rotatable rotating parts on the turntable 111. The slip ring 118 is used to prevent wires and air pipes from getting tangled and to improve the safety of the polishing equipment 100.

[0080] Example 1:

[0081] Embodiment 1 of the present invention proposes a control method for controlling a polishing device 100, the steps of which include:

[0082] Step 201: Obtain the initial interference fringe image when the optical material 400 is not in contact with the clamping cover 113.

[0083] The light emitted from the emitter 161 is a laser beam. The light waves emitted by the laser source have high coherence, meaning that the phase of the light waves remains consistent in both space and time. This coherence allows light waves along different paths to interfere with each other. When the light waves propagate through the multilayer optical material 400, the light waves along different paths will experience different optical path lengths, causing their phases to change. When these coherent light waves are re-superimposed upon exiting, their phase difference will cause interference.

[0084] Step 202: Obtain a real-time interference fringe image when the optical material 400 is in contact with the clamped cover 113.

[0085] The initial and real-time interference fringe images of the optical material 400 can be captured by a camera module and used for comparison operations in subsequent steps.

[0086] Step 203: Calculate the contact pressure of optical material 400.

[0087] The formula for calculating the contact pressure of optical material 400 is as follows: ;

[0088] Where m is the number of moving fringes, obtained by observing the positional difference between the initial interference fringe positions and the real-time interference fringe positions, and λ is the wavelength of the light. The refractive index of the optical material is 400. Let P be the refractive index of the air layer, P be the contact pressure, and E be the Young's modulus of the optical material at 400.

[0089] First, the total optical path difference of the optical material is determined by observing the number of moving fringes. The optical path difference in constructive interference (bright fringes) is an integer multiple of the wavelength of light, denoted as λm, while the optical path difference in destructive interference (dark fringes) is an odd multiple of half the wavelength of light, denoted as (m+0.5)λ. Therefore, the total optical path difference... .

[0090] Phase difference is The phase difference can be used to calculate the thickness change of the stacked optical materials 400. The strain of optical material 400 is calculated based on the thickness change. , Given an initial thickness of 400 for the optical material, the contact pressure is recalculated using strain. .

[0091] However, air gaps exist between the stacked optical materials 400, which can affect light transmission and cause errors. Eliminating these errors allows for more precise contact pressure. Eliminating air layer errors allows for more accurate measurement of optical path difference, thus enabling precise calculation of contact pressure. This improves the accuracy of interferometric measurement results, making the pressure distribution measurement of optical materials 400 more precise.

[0092] Preferably, the wavelength of the light is in the range of 400~700nm, which is within the visible spectrum, and is used to observe the transmission characteristics of materials under visible light.

[0093] Step 204: Determine whether the contact pressure is within the preset stress range.

[0094] Step 205: If the contact pressure is not within the preset pressure range, adjust the distance between the clamping cover 113 and the clamping base 114. If the contact pressure is much less than the preset pressure range, it indicates that the contact pressure on the stacked optical material 400 is still very small. Insufficient contact pressure will lead to insufficient fixation of the optical material 400 in the clamping space, which is not conducive to subsequent polishing. In this case, it is necessary to drive the clamping cover to move closer to the optical material 400. If the contact pressure source is greater than the preset pressure range, it indicates that the contact pressure on the optical material 400 is too large, which can easily damage the optical material 400.

[0095] If the contact pressure is within a preset pressure range, the step of acquiring a real-time interference fringe image when the optical material 400 is in contact with the clamping cover 113 is executed. If the contact pressure is within the preset pressure range, it indicates that the pressure of the clamping cover 113 on the stacked optical material 400 is appropriate, and there is no need to adjust the distance between the clamping cover 113 and the clamping base 114. By controlling the size of the clamping space through electrical signal feedback from the photosensitive component, the problem of not being able to place a sensor on the contact surface between the clamping cover 113 and the optical material 400 is solved, optimizing the detection steps and improving detection efficiency and effect.

[0096] Example 2;

[0097] In Embodiment 2 of the present invention, a control method is proposed for controlling a polishing device 100, the steps of which include:

[0098] Step 301: Obtain the initial interference fringe image when the optical material 400 is not in contact with the clamping cover 113.

[0099] Step 302: Obtain a real-time interference fringe image when the optical material 400 is in contact with the clamped cover 113.

[0100] Step 303: Obtain the initial temperature and real-time temperature of the optical material 400. The emitting end 161 in the photosensitive component can emit infrared light, and the receiving end 162 is used to detect the infrared radiation of the optical material 400 and convert it into an electrical signal to obtain the initial temperature and real-time temperature of the optical material 400.

[0101] Step 304: Calculate the optical path difference of the optical material 400 under pressure change, wherein the optical path difference under pressure change is the difference between the total optical path difference of the optical material 400 and the optical path difference under temperature change of the optical material 400.

[0102] The calculation formula is:

[0103] ;

[0104] ;

[0105] ;

[0106] in, For the total optical path difference, The optical path difference is due to temperature changes. For pressure change and temperature difference, The coefficient of thermal expansion for optical materials is 400. Let ΔT be the refractive index variation coefficient of optical material 400, and ΔT be the temperature change value of the optical material. denoted as , where is the refractive index of optical material 400, k is the stress-optical coefficient of optical material 400, and P is the contact pressure of optical material 400.

[0107] The relationship between the thickness of the optical material 400 and temperature is h(T) = (1 + If ΔT), then the relationship between the refractive index of optical material 400 and temperature is n(T) = (1+ ΔT), L=nh, that is, the optical path difference due to temperature change. = 2n(T)h(T)-2 =2 [1 + ΔT+ ΔT+ (ΔT) 2 -1].

[0108] When optical material 400 is irradiated with laser wavelength, its refractive index change coefficient and thermal expansion coefficient are extremely small. For example, when optical material 400 is a silicon substrate, and the laser wavelength at the emission end is 630 nm, the refractive index change coefficient of the silicon substrate is 1.86 x 10⁻⁶. -4 K -1 The coefficient of thermal expansion of silicon wafers is 2.6 x 10⁻⁶.-6 K -1 Then the equation contains (ΔT) 2 The change is too small to be considered. = 2 (1 ΔT+ ΔT).

[0109] The stress-optic coefficient k is defined as the relative change in refractive index of an optical material 400 under unit stress, i.e., n(P) = +kP, h(P) = Then the pressure change and temperature difference =2n(P)h(P)-2 Substituting and simplifying, we get =2 (k- p= Specifically, when the optical material 400 is quartz, k = 3.4 x 10⁻⁶. - 12 Pa -1 When the material is glass, k = 4.2 x 10⁻⁶. -12 Pa -1 .

[0110] Step 305: Calculate the contact pressure of optical material 400.

[0111] Right now .

[0112] During the polishing process, the optical material 400 generates a large amount of heat through friction with the polishing components. Through the above steps, the influence of the generated heat on the change of contact pressure of the photosensitive components can be effectively reduced, the signal accuracy fed back to the power source can be improved, the pressure of the clamping cover 113 and the clamping base 114 on the optical material 400 can be better adjusted, the optical material 400 can be protected, and the polishing effect can be improved.

[0113] Step 306: Determine whether the contact pressure is within the preset stress range. If the contact pressure is not within the preset pressure range, proceed to step 307; if the contact pressure is within the preset pressure range, proceed to step 302.

[0114] Step 307: Adjust the distance between the clamping cover 113 and the clamping base 114. This adjustment is achieved by transmitting an electrical control signal to the power source that controls the forward and backward movement of the clamping cover 113.

[0115] The present invention also proposes a control device for implementing the above-described control method, the control device comprising:

[0116] The first acquisition module is used to acquire the initial interference fringe position when the optical material 400 is not in contact with the clamping cover 113; the second acquisition module is used to acquire the real-time interference fringe position calculation module when the optical material 400 is in contact with the clamping cover 113, which is used to calculate the contact pressure of the optical material 400 and the optical material 400; the judgment module is used to determine whether the contact pressure is within the preset stress range; the adjustment module is used to adjust the distance between the clamping cover 113 and the clamping base 114 if the contact pressure is not within the preset pressure range.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polishing apparatus for polishing optical materials, characterized in that, include: The main shaft is equipped with a turntable that is coaxially rotatably connected to the main shaft. The main shaft has at least one connecting frame protruding in its circumference. Each connecting frame is provided with a clamping cover. The turntable has at least one clamping bottom protruding. Each clamping cover and a clamping bottom are arranged opposite to each other and limit the clamping space. Each clamping space is provided with stacked optical materials. The corresponding clamping cover and clamping bottom have a direction of movement that moves closer or further away from each other. A polishing assembly is disposed on the rotation trajectory of each of the connecting frames. The two opposing surfaces of the stacked optical materials that contact the clamping cover and the clamping base are pressure surfaces. The side peripheral surface of the optical materials is a polishing surface and is disposed perpendicular to the pressure surface. The polishing assembly has a movement direction that is close to or away from the polishing surface in order to polish the optical materials. A photosensitive component includes at least one pair of emitting ends and receiving ends. One of the clamping cover and the clamping base disposed opposite to each other is provided with one of the emitting ends and the other is provided with one of the receiving ends. A detection optical path is formed between each of the emitting ends and the corresponding receiving ends, and each of the detection optical paths is located within the corresponding clamping space. Each of the clamping covers and each of the clamping bases is provided with a light-transmitting hole. A first connecting tube is provided between each clamping cover and the corresponding connecting frame. A second connecting tube is provided between each clamping base and the turntable. The inner cavities of each first connecting tube and each second connecting tube are connected to each of the light-transmitting holes. Each first connecting tube is provided with an ejector end, and each second connecting tube is provided with a receiver end.

2. The polishing equipment according to claim 1, characterized in that, The polishing assembly includes a first polishing structure and a second polishing structure arranged along the circumference of the turntable. The first polishing structure includes a first brush member rotatably connected to the turntable, and the second polishing structure includes a second brush member rotatably connected to the turntable. The first brush member and the second brush member rotate in different directions. Each clamping cover member is rotatably connected to the corresponding connecting frame, and each clamping bottom member is rotatably connected to the turntable.

3. The polishing equipment according to claim 2, characterized in that, The first polishing structure further includes a lifting shaft and a telescopic shaft. Both the lifting shaft and the telescopic shaft are used to drive the first brush to move closer to or away from the polishing surface. The driving direction of the lifting shaft is perpendicular to the pressure surface, and the driving direction of the telescopic shaft is perpendicular to the polishing surface. The first brush component includes a first brush head and a second brush head spaced apart. The first brush head and the second brush head have rotation directions that are inclined or parallel to each other, so that the rotation axis of the first brush head or the second brush head has an angle A with the polishing surface, and the angle A is 10~90°.

4. The polishing equipment according to claim 2, characterized in that, The second polishing structure further includes a first track and a second track, the first track being perpendicular to the second track, and the second brush including a third brush head and a fourth brush head, the third brush head and the fourth brush head being assembled on the first track so that the third brush head and the fourth brush head have a movement trajectory that moves closer to or further away from each other.

5. The polishing equipment according to claim 1, characterized in that, The polishing equipment further includes a loading structure, which includes a loading platform and at least two positioning baffles mounted on the loading platform. The loading platform has a movement direction that moves toward or away from any of the clamping bases, and at least one of the positioning baffles abuts against two adjacent polishing surfaces of the optical material.

6. A control method, characterized in that, For controlling the polishing apparatus as described in any one of claims 1-5, the steps include: Acquire an initial interference fringe image when the optical material is not in contact with the clamping cover; Acquire a real-time interference fringe image when the optical material is in contact with the clamping cover; Calculate the contact pressure of the optical material; Determine whether the contact pressure is within a preset pressure range; If the contact pressure is not within the preset pressure range, adjust the distance between the clamping cover and the clamping base.

7. A control device, characterized in that, For implementing the control method as described in any one of claims 6, the control device comprises: The first acquisition module is used to acquire the initial interference fringe position when the optical material is not in contact with the clamping cover; The second acquisition module is used to acquire the real-time interference fringe position when the optical material is in contact with the clamping cover. A calculation module is used to calculate the contact pressure of the optical material; The judgment module is used to determine whether the contact pressure is within a preset pressure range; The adjustment module is used to adjust the distance between the clamping cover and the clamping base if the contact pressure is not within the preset pressure range.

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