Cutting device of optical filter and cutting method thereof

Abstract

The application is suitable for the field of laser cutting technology, and provides a cutting device and a cutting method for a filter, the cutting device comprising a laser, a beam shaping module, a first driving assembly, a focusing objective, a workbench and a second driving assembly; the beam shaping module is used for shaping the laser beam emitted by the laser into a linear non-diffracting beam; the beam shaping module is connected with the output shaft of the first driving assembly, and the first driving assembly is used for driving the beam shaping module to the light path of the laser beam or away from the light path of the laser beam; the focusing objective and the workbench are both arranged on the light path of the laser beam, the workbench is connected with the output shaft of the second driving assembly, and the second driving assembly is used for driving the workbench to move relative to the focusing objective. According to the application, the laser beam is shaped into a linear non-diffracting beam by the beam shaping module for pre-cutting, so as to limit the extension direction of the crack in the second cutting through the micro-cracks generated by the pre-cutting, thereby improving the yield of the cut filter.

Description

Technical Field

[0001] This application relates to the field of laser cutting technology, and in particular to a filter cutting device and a cutting method thereof. Background Technology

[0002] Optical filters are optical devices used to select the desired radiation band and have wide applications in fields such as medical treatment, high-performance cameras, and optical communication technology.

[0003] The filter comprises a substrate, an AR film, and a BPF film, with the AR and BPF films respectively disposed on opposite sides of the substrate. The BPF film can be bisphenol F epoxy resin, and the AR film reduces reflection from the substrate surface. Because the AR and BPF films are formed by stacking, the thickness of each deposition is inconsistent, resulting in uneven distribution of internal stress in the AR and BPF films.

[0004] Currently, when cutting filters, if a low-power laser is used, it is difficult to focus inside the filter, making it impossible to cut the filter. Therefore, a high-power laser is usually used for cutting. However, due to the uneven distribution of internal stress in the filter, edge chipping will occur during cutting, reducing the yield of the cut filter. Summary of the Invention

[0005] This application provides a machine cutting method for a filter cutting device, which can improve the yield of cut filters.

[0006] To achieve the above objectives, in a first aspect, embodiments of this application provide a filter cutting apparatus, the filter cutting apparatus comprising:

[0007] A laser for emitting a laser beam;

[0008] A beam shaping module is used to shape the laser beam emitted by the laser into a linear, diffraction-free beam.

[0009] A first driving component, wherein the beam shaping module is connected to the output shaft of the first driving component, and the first driving component is used to drive the beam shaping module onto the optical path of the laser beam, or to drive the beam shaping module away from the optical path of the laser beam;

[0010] A focusing objective lens is disposed in the optical path of the laser beam;

[0011] A worktable is disposed on the optical path of the laser beam and is used to place a filter.

[0012] The second drive assembly is connected to the output shaft of the second drive assembly, and the second drive assembly is used to drive the worktable to move relative to the focusing objective lens;

[0013] When the beam shaping module is located on the optical path of the laser beam, the beam shaping module, the focusing objective lens, and the stage are arranged sequentially along the optical path of the laser beam.

[0014] In some possible implementations of the first aspect, the beam shaping module includes:

[0015] A diffraction axis cone, which is used to shape the laser beam emitted by the laser into a linear, non-diffraction beam;

[0016] A focusing lens group, wherein the diffraction axis conical mirror is disposed in the focusing lens group, the focusing lens group is connected to the output shaft of the first driving component, and the first driving component is used to drive the focusing lens group to or away from the optical path of the laser beam.

[0017] In some possible embodiments of the first aspect, the annular propagation angle of the diffraction axis cone is 0.5°-3°, and the focal length is 250mm-600mm; or / and

[0018] The focal length of the focusing lens group is 250mm-600mm.

[0019] In some possible embodiments of the first aspect, the filter cutting device further includes:

[0020] A beam expander is disposed in the optical path of the laser beam and located between the beam shaping module and the focusing objective.

[0021] In some possible embodiments of the first aspect, the filter cutting device further includes:

[0022] A reflector is disposed in the optical path of the laser beam to change the propagation direction of the laser beam.

[0023] In some possible implementations of the first aspect, the second driving component includes:

[0024] The second driver is connected to the output shaft of the worktable, and the second driver is used to drive the worktable to rotate.

[0025] The third driver is connected to the output shaft of the second driver, and the third driver is used to drive the second driver to move in the horizontal plane;

[0026] The rotation center line of the worktable is perpendicular to the horizontal plane.

[0027] Secondly, embodiments of this application provide a cutting method, the cutting method being based on the filter cutting apparatus described in any of the above technical solutions, the cutting method comprising the following steps:

[0028] The first driving component is controlled to move the beam shaping module onto the optical path of the laser beam;

[0029] The second drive component is controlled to move the worktable along a preset trajectory to pre-cut the filter;

[0030] The first driving component is controlled to bring the beam shaping module away from the optical path of the laser beam;

[0031] The second drive component is controlled to move the worktable along the preset trajectory to perform a second cut on the filter; wherein the laser energy for the pre-cutting of the filter is less than the laser energy for the second cut on the filter.

[0032] In some possible implementations of the second aspect, the step of controlling the second drive component to move the worktable along a preset trajectory to pre-cut the filter includes:

[0033] The second drive component is controlled to drive the central region of the filter through the laser beam via the worktable to cut the filter and form a baseline;

[0034] The second drive component is controlled to drive the filter through the worktable to cut the filter sequentially on both sides of the baseline, with the baseline as the reference, so as to pre-cut the filter.

[0035] In some possible implementations of the second aspect, after the step of controlling the second drive assembly to drive the filter via the worktable to cut the filter sequentially on both sides of the baseline, the method further includes:

[0036] Control the second drive component to rotate the worktable 90°;

[0037] The steps include controlling the second driving component to drive the central region of the filter through the worktable to pass through the laser beam to cut the filter and form a baseline; and controlling the second driving component to drive the filter through the worktable to cut the filter sequentially on both sides of the baseline with the baseline as a reference.

[0038] In some possible implementations of the second aspect, the step of controlling the second drive assembly to drive the filter via the worktable to cut the filter sequentially on both sides of the baseline, with the baseline as a reference, includes:

[0039] The second drive component is controlled to drive the filter to move sequentially along a direction parallel to the baseline on one side of the baseline via the worktable, with the baseline as the reference.

[0040] The second drive component is controlled to drive the filter via the worktable to move sequentially on the other side of the baseline, in a direction parallel to the baseline, with the baseline as the reference.

[0041] In some possible implementations of the second aspect, the step of controlling the second drive assembly to drive the filter via the worktable to cut the filter sequentially on both sides of the baseline, with the baseline as a reference, includes:

[0042] The second drive component is controlled to drive the filter via the worktable, moving it alternately on both sides of the baseline in a direction parallel to the baseline, with the baseline as the reference.

[0043] In some possible implementations of the second aspect, the laser beam has a pulse width of 500 fs-20 ps, ​​a wavelength of 1030 nm-1064 nm, and a spectral width of 1 nm-5 nm.

[0044] In some possible implementations of the second aspect, the dot pitch on the filter is 5μm-25μm.

[0045] In some possible implementations of the second aspect, the focal depth t of the laser beam pre-cutting the filter and the thickness t1 of the filter satisfy the following relationship:

[0046] 30%t1 < t < 60%t1.

[0047] The filter cutting device and method provided in this application embodiment have a worktable connected to the output shaft of a second driving component. The second driving component moves the worktable relative to the focusing objective, thereby causing a relative displacement between the filter and the laser beam, achieving filter cutting. The focusing objective is used to focus the laser beam so that the energy of the laser beam can achieve the purpose of cutting the filter. The beam shaping module is connected to the output shaft of a first driving component, so that the first driving component drives the beam shaping module onto the optical path of the laser beam, thereby shaping the laser beam into a linear, non-diffractive beam. Then, the linear, non-diffractive beam is used to pre-cut the filter. Since the linear, non-diffractive beam has relatively high efficiency, the beam cutting method is more efficient. The long focal depth allows for the generation of microcracks within the filter using a low-power, high-frequency linear non-diffraction beam. A first driving component then guides the beam shaping module away from the laser beam's optical path, enabling the direct use of a high-power, low-frequency laser beam to cut the filter, ensuring that the paths of the two filter cuts coincide. The microcracks generated during the pre-cut filter restrict the direction of crack extension during the second cut, thus guiding the direction of cracks generated during the second cut. This reduces edge chipping during filter cutting, improves issues such as edge chipping, demolding, and random cracking, and increases the yield of the cut filter. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the structure of an embodiment of the filter cutting apparatus of this application;

[0050] Figure 2 This is a schematic diagram of another embodiment of the filter cutting apparatus of this application;

[0051] Figure 3 This is a flowchart illustrating the cutting method of this application;

[0052] Figure 4 for Figure 3 Detailed flowchart of step S20;

[0053] Figure 5 for Figure 4 A detailed flowchart of an embodiment of step S22;

[0054] Figure 6 for Figure 4A detailed flowchart of another embodiment of step S22.

[0055] Explanation of icon numbers:

[0056] 1. Laser; 2. Beam shaping module; 21. Diffraction axis cone; 22. Focusing lens group; 3. First drive assembly; 4. Focusing objective lens; 5. Stage; 6. Beam expander; 7. Reflector; 8. Optical shutter.

[0057] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0059] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0060] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "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 application 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 application.

[0061] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0062] 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 application, "multiple" means two or more, unless otherwise explicitly specified.

[0063] This application provides a filter cutting device and method to solve the technical problem of low yield of cut filters.

[0064] In the embodiments of this application, such as Figure 1 and Figure 2 As shown, the filter cutting device includes a laser 1, a beam shaping module 2, a first driving assembly 3, a focusing objective 4, a stage 5, and a second driving assembly. The laser 1 is used to emit a laser beam; the beam shaping module 2 is used to shape the laser beam emitted by the laser 1 into a linear, non-diffractive beam; the beam shaping module 2 is connected to the output shaft of the first driving assembly 3, which is used to move the beam shaping module 2 onto or away from the optical path of the laser beam; the focusing objective 4 and the stage 5 are both disposed on the optical path of the laser beam, and the stage 5 is used to place the filter; the stage 5 is connected to the output shaft of the second driving assembly, which is used to move the stage 5 relative to the focusing objective 4; wherein, when the beam shaping module 2 is located on the optical path of the laser beam, the beam shaping module 2, the focusing objective 4, and the stage 5 are arranged sequentially along the optical path of the laser beam.

[0065] In this embodiment, laser 1 can be a pulsed laser, specifically a picosecond laser pulser, used to generate picosecond pulsed laser light. Using the pulsed laser generated by pulsed laser 1 to cut the filter can avoid melting the cut area on the filter. The cutting device is particularly suitable for cutting narrowband filters.

[0066] Before cutting the filter, the UV film is first fixed on the steel ring, and then the BPF film layer of the filter is attached to the UV film layer to fix the filter. Then the steel ring is placed on the worktable 5. The UV film can be a UV-cured film.

[0067] During filter cutting, the first driving component 3 is controlled to move the beam shaping module 2 onto the optical path of the laser beam. Then, the laser 1 is activated to generate a low-power, high-frequency laser beam. As the laser beam passes through the beam shaping module 2, it is shaped into a linear, non-diffractive beam, essentially transforming a Gaussian beam into a Bessel beam. Finally, the shaped linear, non-diffractive beam is focused by the focusing objective 4 and then illuminates the filter on the stage 5. The second driving component is then moved to move the filter relative to the laser beam via the stage 5, thus pre-cutting the filter. Next, the first driving component 3 is controlled to move the beam shaping module 2 away from the optical path of the laser beam, and the laser 1 is controlled to generate a high-power, low-frequency laser beam. This laser beam, after passing through the focusing objective 4, directly illuminates the filter. The second driving component then moves the filter relative to the laser beam, achieving a second cut to the filter. During the pre-cutting and second-cutting of the filter, the irradiation paths of the laser beam on the filter completely overlap; when the power used exceeds 30% of the maximum power of laser 1, it is generally considered to be high power, and when the power used is less than 30% of the maximum power of laser 1, it is generally considered to be low power; generally, frequencies greater than or equal to 50KHz are considered high frequency, and frequencies less than 50KHz are considered low frequency.

[0068] When pre-cutting the filter, after cutting along the first direction, the second drive component can be controlled to rotate the filter by 90° and then cut again along the same direction to achieve pre-cutting of the filter. For example, if the cutting trajectory on the filter is equidistant parallel lines before rotation, then after rotating 90°, the cutting trajectory on the filter is also equidistant parallel lines. The superposition of the trajectories before and after rotation creates a grid-like cutting trajectory on the filter, thus achieving pre-cutting of the filter.

[0069] During pre-cutting, the filter can be cut from the middle to both sides to reduce internal stress and improve the yield of the cut filter.

[0070] In this embodiment, the stage 5 is connected to the output shaft of the second driving component, so that the second driving component drives the stage 5 to move relative to the focusing lens 4, thereby causing a relative displacement between the filter and the laser beam, achieving the cutting of the filter; the focusing lens 4 is used to focus the laser beam so that the energy of the laser beam can achieve the purpose of cutting the filter; the beam shaping module 2 is connected to the output shaft of the first driving component 3, so that the first driving component 3 drives the beam shaping module 2 onto the optical path of the laser beam, thereby shaping the laser beam into a linear non-diffraction beam, and then using the linear non-diffraction beam to pre-cut the filter. Since the linear non-diffraction beam has a long depth of focus, it can effectively cut the filter. A low-power, high-frequency linear non-diffraction beam can generate microcracks within the filter. Then, the beam shaping module 2 is taken away from the optical path of the laser beam by the first driving component 3, so that the high-power, low-frequency laser beam generated by the laser 1 can be used directly to cut the filter, making the paths of the two filter cuts coincide. Then, the microcracks generated by the pre-cut filter limit the extension direction of the cracks in the filter during the second cut, so that the microcracks generated by the pre-cut filter guide the direction of the cracks generated during the second cut, thereby reducing the degree of edge chipping during filter cutting, improving problems such as edge chipping, demolding, and random cracking caused by cutting, and improving the yield of cut filters.

[0071] In one embodiment, such as Figure 1 and Figure 2 As shown, the filter cutting device also includes an optical shutter 8, which is located at the light output port of the laser 1 to control whether the laser 1 can emit a laser beam.

[0072] In one embodiment, such as Figure 1 and Figure 2 As shown, the beam shaping module 2 includes a diffraction axis conical mirror 21 and a focusing mirror group 22. The diffraction axis conical mirror 21 is used to shape the laser beam emitted by the laser 1 into a linear non-diffraction beam. The diffraction axis conical mirror 21 is disposed on the focusing mirror group 22. The focusing mirror group 22 is connected to the output shaft of the first driving component 3. The first driving component 3 is used to drive the focusing mirror group 22 into or away from the optical path of the laser beam.

[0073] Since the focusing lens group 22 is connected to the output shaft of the first driving component 3, and the diffraction axis conical mirror 21 is disposed on the focusing lens group 22, the first driving component 3 can drive the focusing lens group 22 and the diffraction axis conical mirror 21 together onto or away from the optical path of the laser beam. The diffraction axis conical mirror 21 can shape the laser beam into a linear non-diffraction beam, that is, it can shape a Gaussian beam into a Bessel beam; the focusing lens group 22 is used to focus the linear non-diffraction beam and prevent the linear non-diffraction beam from diverging.

[0074] Specifically, the first drive assembly 3 includes a first driver, and the focusing lens group 22 is connected to the output shaft of the first driver so as to drive the focusing lens group 22 and the diffraction axis cone mirror 21 to move together through the first driver.

[0075] In one embodiment, the annular propagation angle of the diffraction axis cone 21 is 0.5°-3°, the focal length is 250mm-600mm, and the focal depth of the linear non-diffractive beam is 10μm-50μm. By limiting the annular propagation angle and focal length of the diffraction axis cone 21, the focal depth of the linear non-diffractive beam can be adjusted. By limiting the focal depth of the linear non-diffractive beam, the thickness of the modifier layer applied to the filter during filter cutting can be adjusted, thereby improving the edge chipping problem during cutting and increasing the yield of the cut filter. The modifier layer refers to the area where the linear non-diffractive beam influences the interior of the filter.

[0076] In one embodiment, the focal length of the focusing lens group 22 is 250mm-600mm, so as to adjust the position of the focal point so that the laser beam irradiating the filter can pre-cut the filter to facilitate the formation of the modified layer and avoid the situation where the modified layer cannot be formed. Then, a second cutting is performed to realize the slicing of the filter.

[0077] In one embodiment, such as Figure 1 and Figure 2 As shown, the filter cutting device also includes a beam expander 6, which is disposed in the optical path of the laser beam and located between the beam shaping module 2 and the focusing objective lens 4. The beam expander 6 is used to reduce the energy density of the laser beam so as to form a modified layer inside the filter.

[0078] In one embodiment, such as Figure 1 and Figure 2 As shown, the filter cutting device also includes a reflector 7, which is disposed on the optical path of the laser beam to change the propagation direction of the laser beam, thereby adjusting the overall layout of the cutting device to facilitate a reduction in the size of the cutting device.

[0079] Specifically, a reflector 7 can be installed between the laser 1 and the beam shaping module 2, between the beam shaping module 2 and the beam expander 6, and between the beam expander 6 and the focusing objective lens 4.

[0080] In one embodiment, the second driving assembly includes a second driver and a third driver. The worktable 5 is connected to the output shaft of the second driver, which drives the worktable 5 to rotate. The second driver is also connected to the output shaft of the third driver, which drives the second driver to move in a horizontal plane. The rotation center line of the worktable 5 is perpendicular to the horizontal plane. The second and third drivers can respectively drive the filter on the worktable 5 to rotate relative to the laser beam and move linearly in the horizontal plane, thereby facilitating the cutting of the filter.

[0081] In addition, such as Figure 3 As shown in the embodiments of this application, a cutting method is also provided. The cutting method is based on the filter cutting apparatus described in any of the above embodiments, and the cutting method includes the following steps:

[0082] Step S10: Control the first driving component to move the beam shaping module onto the optical path of the laser beam;

[0083] Step S20: Control the second drive component to move the worktable along a preset trajectory to pre-cut the filter;

[0084] Step S30: Control the first driving component to bring the beam shaping module away from the optical path of the laser beam;

[0085] Step S40: Control the second drive component to move the worktable along a preset trajectory to perform a second cut on the filter.

[0086] Before cutting, the UV film is first fixed on the steel ring, and then the BPF film layer of the filter is attached to the UV film to fix the filter. Then the steel ring with the filter fixed is placed on the worktable 5 so that the laser beam can irradiate the filter on the worktable 5 to cut the filter.

[0087] When the filter cutting begins, the first driving component 3 is controlled to move the beam shaping module 2 into the optical path of the laser beam. This allows the laser beam emitted by the laser 1 to be shaped by the beam shaping module 2, thus shaping the laser beam emitted by the laser 1 into a linear, non-diffractive beam. The linear, non-diffractive beam has a longer depth of focus, which can form a modified layer of a certain thickness inside the filter. In other words, the beam shaping module 2 shapes the laser beam emitted by the laser 1 into a Bessel beam.

[0088] Then, the second drive component is controlled to move the worktable 5 along a preset trajectory. When the worktable 5 moves, the filter placed on the worktable 5 also moves along with it, but the laser beam remains stationary. That is, the second drive component can drive the filter to move relative to the laser beam through the worktable 5. After the filter is irradiated with linear non-diffraction, a modified layer is generated in the filter, which causes microcracks to be generated on the modified layer of the filter, thereby realizing the pre-cutting of the filter.

[0089] After controlling the first drive component 3 to move the beam shaping module 2 to the optical path of the laser beam, and before controlling the second drive component to move the worktable 5 along the preset trajectory, it is also necessary to turn on the laser 1 to generate a low-power, high-frequency laser beam.

[0090] Then, the first driving component 3 is controlled to move the beam shaping module 2 away from the optical path of the laser beam, so that the beam shaping module 2 avoids the optical path of the laser beam. Since the beam shaping module 2 is not in the optical path of the laser beam, the laser beam emitted by the laser 1 can directly irradiate the filter, that is, the laser beam that cuts the filter for the second time is a Gaussian beam.

[0091] Before controlling the first driving component 3 to take the beam shaping module 2 away from the optical path of the laser beam, the laser 1 can be turned off first to avoid the presence of the laser beam in the optical path, and then the beam shaping module 2 can be taken away from the optical path of the laser beam.

[0092] After the beam shaping module 2 avoids the optical path of the laser beam, when the second driving component is controlled to move the worktable 5, the cutting trajectory of the laser beam cutting the filter is the same as the preset trajectory when the filter is pre-cut. That is, the cutting position when the filter is cut for the second time is exactly the same as the cutting position when the filter is pre-cut, so that the filter can be cut twice at the same cutting position.

[0093] After the beam shaping module 2 avoids the optical path of the laser beam, before the second drive component moves the worktable 5 along the preset trajectory, the laser 1 needs to be turned on to generate a high-power, low-frequency laser beam. That is, the laser energy of the high-power, low-frequency laser beam is greater than the laser energy of the low-power, high-frequency laser beam, so that the laser energy for pre-cutting the filter is less than the laser energy for the second cut of the filter. Because the laser energy for pre-cutting is smaller, microcracks can be generated; the laser energy for the second cut is larger, so the cracks generated in the filter are larger. The microcracks generated by pre-cutting can guide the direction of the cracks generated by the second cut of the filter, thereby reducing the degree of edge chipping during filter cutting, improving problems such as edge chipping, demolding, and random cracking caused during cutting, and improving the yield of cut filters.

[0094] In this embodiment, the laser beam generated by laser 1 has a pulse width of 500 fs-20 ps, ​​a wavelength of 1030 nm-1064 nm, and a spectral width of 1 nm-5 nm. Limiting the pulse width makes it easier for cracks to form in the filter along its thickness direction under laser beam irradiation; limiting the wavelength makes it easier for the laser beam to penetrate the AR film layer on the filter surface, preventing excessively high reflectivity of the filter; and limiting the spectral width makes the energy distribution of the laser beam within the filter more stable, making it easier to generate cracks inside the filter. Specifically, this embodiment is particularly suitable for cutting narrowband filters.

[0095] In this embodiment, the dot pitch of the light irradiating the filter is 5μm-25μm, and the energy density of the linear non-diffraction beam is greater than 0.8J / cm². By limiting the dot pitch of the light irradiating the filter, it is easier for the modified layer inside the filter to generate cracks. If the dot pitch is too small, melting is likely to occur, resulting in excessive regional energy and preventing the internal cracks from extending; if the dot pitch is too large, the cracks generated by the individual pulse irradiation points cannot connect together, affecting the yield of the cut filter.

[0096] Understandably, dot pitch refers to the distance between two adjacent laser pulses when each laser pulse irradiates the filter.

[0097] In this embodiment, the focal depth t of the laser beam that pre-cuts the filter and the thickness t1 of the filter satisfy the following relationship:

[0098] 30%t1 < t < 60%t1.

[0099] Understandably, the focal depth of the laser beam is equal to the thickness of the modified layer, which is between 30% and 60% of the filter thickness. The longer the focal depth, the larger the area of ​​influence of the laser beam within the filter. Therefore, limiting the focal depth can restrict the extension length of cracks generated inside the filter during each cut, thereby improving issues such as edge chipping and demolding, and increasing the yield of cut filters.

[0100] In one embodiment, such as Figure 4 As shown, step S20 includes the following steps:

[0101] Step S21: Control the second drive component to drive the central region of the filter through the laser beam via the worktable to cut the filter and form a baseline;

[0102] Step S22: Control the second drive component to drive the filter through the worktable to cut the filter on both sides of the baseline in sequence, so as to pre-cut the filter.

[0103] When the second drive assembly moves the central region of the filter through the laser beam via the stage 5, the laser beam irradiates the central region of the filter to form a modified layer therein. For ease of description, the cutting trajectory of the laser beam in the central region of the filter is defined as the baseline, and the area where the baseline is located is the modified layer.

[0104] Then, using the baseline as a reference, the second drive component moves the worktable 5, which in turn moves the filter sequentially on both sides of the baseline relative to the laser beam, thereby cutting the filter. Since the baseline is located in the middle region of the filter, and the baseline is formed first and then cut on both sides of the baseline, the internal stress of the filter can be reduced, which can improve problems such as demolding and random cracking, and increase the yield of the cut filter.

[0105] After step S22, the second drive component can be controlled to rotate the worktable 5 by 90°, so that the worktable 5 can rotate the filter by 90°. Then, steps S21 and S22 are executed again to directly cut the filter into a finished product. That is, after rotating 90° and executing steps S21 and S22 again, the filter can be cut into a grid.

[0106] In one embodiment, such as Figure 5 As shown, step S22 includes the following steps:

[0107] Step S221: Control the second drive component to drive the filter to move sequentially along a direction parallel to the baseline on one side of the baseline via the worktable, with the baseline as the reference.

[0108] Step S222: Control the second drive component to drive the filter to move sequentially on the other side of the baseline, in a direction parallel to the baseline, using the worktable as a reference.

[0109] When controlling the second drive assembly to move the filter along the baseline via the worktable 5, it can move sequentially along a direction parallel to the baseline on one side, so as to cut one side of the baseline first. Each cut can be made at equal intervals; that is, in multiple cuts on one side of the baseline, the cutting trajectory is parallel to the baseline each time, and the distance between any two adjacent cutting trajectories can be the same. Then, the second drive assembly is controlled to move the filter along a direction parallel to the baseline on the other side, i.e., cutting the other side of the baseline in the same way. The cutting method of this embodiment can improve cutting efficiency.

[0110] In another alternative embodiment, such as Figure 6 As shown, step S22 includes the following steps:

[0111] Step S223: Control the second drive component to drive the filter to move alternately on both sides of the baseline, in a direction parallel to the baseline, using the worktable as a reference.

[0112] Step S223 in this embodiment is an optional embodiment parallel to the embodiments of steps S221 and S222 described above.

[0113] In this embodiment, when the second drive component is controlled to move the filter with the baseline as a reference through the worktable 5, it moves alternately on both sides of the baseline in a direction parallel to the baseline. That is, it cuts once on one side of the baseline and then cuts once on the other side of the baseline. This alternating cutting can better release the internal stress of the filter and improve the yield of the cut filter.

[0114] Understandably, since the laser beam emitted by the laser 1 directly cuts the filter trajectory after the beam shaping module 2 avoids the optical path of the laser beam, and the trajectory is the same as the preset trajectory, the trajectory of the second cut of the filter is the same as the preset trajectory described in any of the above embodiments, and will not be repeated here.

[0115] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A cutting method, characterized in that, The cutting method is based on a filter cutting device, the cutting device comprising: A laser for emitting a laser beam; A beam shaping module is used to shape the laser beam emitted by the laser into a linear, diffraction-free beam. A first driving component, wherein the beam shaping module is connected to the output shaft of the first driving component, and the first driving component is used to drive the beam shaping module onto the optical path of the laser beam, or to drive the beam shaping module away from the optical path of the laser beam; A focusing objective lens is disposed in the optical path of the laser beam; A worktable is disposed on the optical path of the laser beam and is used to place a filter. The second drive assembly is connected to the output shaft of the second drive assembly, and the second drive assembly is used to drive the worktable to move relative to the focusing objective lens; When the beam shaping module is located in the optical path of the laser beam, the beam shaping module, the focusing objective lens, and the stage are arranged sequentially along the optical path of the laser beam. The cutting method includes the following steps: The first driving component is controlled to move the beam shaping module onto the optical path of the laser beam; The second drive component is controlled to move the worktable along a preset trajectory to pre-cut the filter. The low-power, high-frequency linear non-diffraction beam can generate microcracks in the filter. The first driving component is controlled to bring the beam shaping module away from the optical path of the laser beam; The second drive component is controlled to move the worktable along the preset trajectory to perform a second cut on the filter, directly using the high-power, low-frequency laser beam generated by the laser to cut the filter; wherein, the laser energy for the pre-cutting of the filter is less than the laser energy for the second cut of the filter; high power is defined as the power used exceeds 30% of the maximum power of the laser, and low power is defined as the power used is less than 30% of the maximum power of the laser; high frequency is defined as greater than or equal to 50 kHz, and low frequency is defined as less than 50 kHz.

2. The cutting method as described in claim 1, characterized in that, The step of controlling the second drive component to move the worktable along a preset trajectory to pre-cut the filter includes: The second drive component is controlled to drive the central region of the filter through the laser beam via the worktable to cut the filter and form a baseline; The second drive component is controlled to drive the filter through the worktable to cut the filter sequentially on both sides of the baseline, with the baseline as the reference, so as to pre-cut the filter.

3. The cutting method as described in claim 2, characterized in that, After the step of controlling the second drive component to drive the filter to cut the filter sequentially on both sides of the baseline using the worktable, the method further includes: Control the second drive component to rotate the worktable 90°; The steps include controlling the second driving component to drive the central region of the filter through the worktable to pass through the laser beam to cut the filter and form a baseline; and controlling the second driving component to drive the filter through the worktable to cut the filter sequentially on both sides of the baseline with the baseline as a reference.

4. The cutting method as described in claim 2, characterized in that, The step of controlling the second driving component to drive the filter via the worktable to cut the filter sequentially on both sides of the baseline, with the baseline as a reference, includes: The second drive component is controlled to drive the filter to move sequentially along a direction parallel to the baseline on one side of the baseline via the worktable, with the baseline as the reference. The second drive component is controlled to drive the filter via the worktable to move sequentially on the other side of the baseline, in a direction parallel to the baseline, with the baseline as the reference.

5. The cutting method as described in claim 2, characterized in that, The step of controlling the second driving component to drive the filter via the worktable to cut the filter sequentially on both sides of the baseline, with the baseline as a reference, includes: The second drive component is controlled to drive the filter via the worktable, moving it alternately on both sides of the baseline in a direction parallel to the baseline, with the baseline as the reference.

6. The cutting method as described in claim 1, characterized in that, The laser beam has a pulse width of 500 fs-20 ps, ​​a wavelength of 1030 nm-1064 nm, and a spectral width of 1 nm-5 nm.

7. The cutting method as described in claim 1, characterized in that, The dot pitch on the filter is 5μm-25μm.

8. The cutting method as described in claim 1, characterized in that, The focal depth t of the laser beam pre-cutting the filter and the thickness t1 of the filter satisfy the following relationship: 30%t1 < t < 60%t1.

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