CN115383287B - Beam splitting type automatic focusing system and method - Google Patents
Beam splitting type automatic focusing system and method Download PDFInfo
- Publication number
- CN115383287B CN115383287B CN202210574173.9A CN202210574173A CN115383287B CN 115383287 B CN115383287 B CN 115383287B CN 202210574173 A CN202210574173 A CN 202210574173A CN 115383287 B CN115383287 B CN 115383287B
- Authority
- CN
- China
- Prior art keywords
- ccd camera
- image
- beam splitter
- splitting
- focusing lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 23
- 230000008859 change Effects 0.000 claims abstract description 29
- 230000007246 mechanism Effects 0.000 claims abstract description 12
- 238000012545 processing Methods 0.000 abstract description 22
- 230000008569 process Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 6
- 238000009826 distribution Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000009022 nonlinear effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/04—Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
- B23K26/046—Automatically focusing the laser beam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/067—Dividing the beam into multiple beams, e.g. multifocusing
- B23K26/0673—Dividing the beam into multiple beams, e.g. multifocusing into independently operating sub-beams, e.g. beam multiplexing to provide laser beams for several stations
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/282—Autofocusing of zoom lenses
Abstract
The invention relates to a beam-splitting automatic focusing system which is characterized by comprising an image fitting computer, a motion executing mechanism, an object focusing lens, a grating beam splitter, an image focusing lens and a CCD camera, wherein the object focusing lens, the grating beam splitter, the image focusing lens and the CCD camera are sequentially arranged along a reflection light path, the center of the grating beam splitter, the center of the image focusing lens and the center of a light receiving surface of the CCD camera are collinear, and an included angle exists between the light receiving surface of the CCD camera and the image focusing lens; the image fitting computer is electrically connected with the CCD camera; the motion actuating mechanism can selectively drive the sample or the object focusing lens to move through the superposition condition of the minimum point and the center point of the light spot diameter change curve, can realize rapid and accurate real-time automatic focusing in the laser processing process, does not need complex light paths and high-difficulty computer processing, and also provides a beam-splitting automatic focusing method.
Description
Technical Field
The invention relates to the technical field of optical detection, in particular to a beam-splitting automatic focusing system and a beam-splitting automatic focusing method.
Background
The laser has the characteristics of high brightness, strong directivity, high energy, dense distribution and the like, and after the laser irradiates the surface of the material, the material can absorb a large amount of photon energy in a short time to raise the temperature, and the melting state and even the gasification state are achieved, so that the laser can realize the function of processing the material. In recent years, due to the great advantages of non-contact property, high efficiency, flexibility, small heat effect, high precision and the like of laser processing, the laser processing starts to infiltrate into a plurality of industries, and the processing operations including welding, cutting, punching, etching, polishing, rapid prototyping and the like can be realized, so that the trend of replacing the traditional processing technologies is greatly promoted.
However, laser processing generally needs to be in a focusing state, so that the energy density of laser can be greatly increased, not only can the energy required by laser action be reduced, but also accurate and precise processing can be realized due to the characteristic of small focusing spot size. In the out-of-focus state, the energy density is reduced, which affects the processing quality and even makes the processing impossible. Particularly in the field of ultrafast laser applications, an extremely high peak power density can only be achieved by focusing the laser, and nonlinear effects can only be generated at the focus to obtain extreme processing effects. It can be seen that precise control of the focal position is necessary to achieve high quality and precise laser machining results.
At present, the laser focusing method can be mainly classified into a sensor type and a CCD type. The sensor type focusing is to install a height sensor on a paraxial of a focusing light path, and the deviation between the value returned by the height sensor and the calibrated focus position is used for feeding back to an executing mechanism to realize the alignment of the focus. However, the biggest problem with this approach is that it is not controlled in real time. Because the laser focusing light path is not coaxial with the height sensor, the height value detected by the height sensor is not the height value of the position of the focus, and if the data is directly fed back, the focus is delayed or advanced. Therefore, the method often needs to perform a pre-scan on the surface of the processed sample to obtain a two-dimensional distribution of the height values of the sample surface, and then perform corresponding focus alignment in the processing process. Obviously, the accuracy of the method depends on the accuracy of the value of the height sensor, the position without the value cannot be subjected to focus alignment, and the pre-scanning increases the processing steps and the processing time.
The CCD focusing is an automatic focusing mode utilizing the light reflection principle, the CCD is directly adopted to receive reflected light on a coaxial light path, then the state of the current focus position is identified through computer processing, the state is fed back to an executing mechanism to perform counterpoint operation, and the CCD is cycled until focusing is completed, so that the CCD focusing device has the advantage of real-time control. Obviously, this method requires precise alignment, and has high requirements for pixels and computer processing of the CCD, which increases the cost. In order to reduce the requirement in this aspect, the light spot at the focus position received by the CCD can have a certain difference from the light spot at the non-focus position through a certain optical design, so that the sensitivity of focus identification can be increased, and the requirements on the CCD and the computer processing are reduced.
For example, a focusing device with a grating lens added in a light path is proposed in the currently published patent (CN 102122055A), so that the functions that a light spot at a focus position is a perfect circle and a light spot at a defocusing state is a semicircle can be realized, thus the defocusing state can be rapidly judged, a motor is controlled in one direction, and the work of processing a large amount of image information is reduced. However, this method has a strict requirement on the position of the grating lens, and half of the laser beam needs to be filtered, which increases the difficulty of practical operation. Also disclosed in the patent (CN 110530291 a) is a grating projection method to create a three-dimensional profile of the sample surface, which also puts high demands on computer processing.
Disclosure of Invention
Based on the above description, the invention provides a beam-splitting automatic focusing system to realize rapid and accurate real-time automatic focusing in the laser processing process, and complicated light paths and high-difficulty computer processing are not needed.
The technical scheme for solving the technical problems is as follows:
the beam splitting type automatic focusing system comprises an image fitting computer, a motion executing mechanism, and an object side focusing lens, a grating beam splitter, an image side focusing lens and a CCD camera which are sequentially arranged along a reflecting light path, wherein the center of the grating beam splitter, the center of the image side focusing lens and the center of a light receiving surface of the CCD camera are collinear;
the object focusing lens is used for collimating reflected laser reflected by the surface of the sample;
the grating beam splitter is used for splitting the collimated reflected laser into at least 3 beam splitting beams;
the image space focusing lens is used for focusing all the split light beams formed by splitting the grating beam splitter;
the CCD camera is used for receiving the spot image of the focused beam-splitting light beam, and an included angle exists between the light receiving surface of the CCD camera and the image space focusing lens;
the image fitting computer is electrically connected with the CCD camera and is used for performing image fitting on the light spot image acquired by the CCD camera and obtaining a light spot diameter change curve;
and the motion executing mechanism can selectively drive the sample or the object focusing lens to move according to the superposition condition of the minimum point and the center point of the light spot diameter change curve until the minimum point and the center point are superposed.
Compared with the prior art, the technical scheme of the application has the following beneficial technical effects:
according to the beam splitting type automatic focusing system, because an included angle exists between the image side focusing lens and the light receiving surface of the CCD camera, an included angle exists between the focal plane formed by each beam splitting light beam and the light receiving surface of the CCD camera, so that a series of light spots detected by the CCD camera have size difference, a minimum value exists in a light spot diameter change curve obtained by an image fitting computer, a center point also exists, if a laser focus is located on the surface of a sample at the moment, the light spot diameter change curve obtained by fitting is in a completely symmetrical state, and the minimum value of the light spot diameter change curve coincides with the center point. If the laser focus is in an defocusing state, the fitted light spot diameter change curve is in an asymmetric state, the minimum value of the fitted light spot diameter change curve is not coincident with the center point, and the automatic focusing can be realized by driving a sample or an object focusing lens to move through the motion executing mechanism according to the principle.
On the basis of the technical scheme, the invention can be improved as follows.
In one of the solutions, the grating beam splitter is arranged parallel to the image-side focusing mirror.
In another aspect, the light receiving surface of the CCD camera is disposed parallel to the grating beam splitter.
Further, the device also comprises a light guide lens, wherein the light guide lens is arranged between the object focusing lens and the grating beam splitter and is used for guiding the collimated reflected laser to the grating beam splitter for beam splitting.
The application also provides a beam-splitting type automatic focusing method, which comprises the following steps:
s1, arranging an object side focusing lens, a grating beam splitter, an image side focusing lens and a CCD camera in sequence along a reflection light path, wherein an included angle exists between a light receiving surface of the CCD camera and the image side focusing lens, and the center of the grating beam splitter, the center of the image side focusing lens and the center of the light receiving surface of the CCD camera are collinear;
s2, collimating reflected laser reflected by the surface of the sample through an object focusing mirror;
s3, splitting the collimated reflected laser into at least three split beams through a grating beam splitter;
s4, focusing all the split light beams formed by splitting the grating beam splitter through an image space focusing lens;
s5, receiving a spot image of the focused split beam through a CCD camera;
s6, performing image fitting on the spot image obtained by the CCD camera through an image fitting computer to obtain a spot diameter change curve, judging whether the minimum point and the center point of the spot diameter change curve coincide, and if so, ending focusing operation; if not, carrying out step S7;
and S7, driving the sample or the object focusing lens to move through the motion executing mechanism, and repeating the steps S2-S6.
Further, the grating beam splitter is arranged in parallel with the image space focusing mirror.
Further, the light receiving surface of the CCD camera is arranged in parallel with the grating beam splitter.
Further, the step S1 further includes disposing a light guide lens between the object focusing lens and the grating beam splitter; in step S3, before the collimated reflected laser beam is split into at least three split beams by the grating beam splitter, the method further includes guiding the collimated reflected laser beam to the grating beam splitter by a light guide lens.
According to the beam splitting type automatic focusing method, through the design that an included angle exists between the image side focusing lens and the light receiving surface of the CCD camera, the image fitting computer fits the symmetrical defocusing state to obtain the light spot diameter change curve, so that the accuracy of the focal point position is calibrated by the minimum position of the image fitting computer, the beam splitting type automatic focusing method is not complex, quick response can be obtained, and high-accuracy real-time automatic focusing is achieved.
Drawings
Fig. 1 is a schematic diagram of steps of a beam-splitting auto-focusing system according to a first embodiment of the present invention;
FIG. 2 is a schematic diagram of focusing a light spot according to a first embodiment of the present invention;
fig. 3 is a schematic structural diagram of another beam-splitting auto-focusing system according to a second embodiment of the present invention;
FIG. 4 is a schematic diagram of focusing a light spot according to a second embodiment of the present invention;
FIG. 5 is a schematic diagram of the spot distribution of a split beam on a CCD camera;
fig. 6 is a schematic block diagram of motion control according to the first and second embodiments of the present invention.
Detailed Description
In order to facilitate an understanding of the present application, a more complete description of the present application will now be provided with reference to the relevant figures. Examples of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be appreciated that spatially relative terms such as "under … …," "under … …," "below," "under … …," "over … …," "above," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "under … …" and "under … …" may include both an upper and a lower orientation. Furthermore, the device may also include an additional orientation (e.g., rotated 90 degrees or other orientations) and the spatial descriptors used herein interpreted accordingly.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. In the following embodiments, "connected" is understood to mean "electrically connected", "communicatively connected", and the like, if the connected circuits, modules, units, and the like have electrical or data transferred therebetween.
As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.
Example 1
As shown in fig. 1, 2, 5 and 6, the present embodiment provides a beam-splitting auto-focusing system, which includes an image fitting computer 5, a motion actuator 6, and an object focusing lens 1, a grating beam splitter 2, an image focusing lens 3 and a CCD camera 4 sequentially disposed along a reflection light path, wherein three points of a center of the grating beam splitter 2, a center of the image focusing lens 3 and a center of a light receiving surface of the CCD camera 4 are collinear, in the present embodiment, the image focusing lens 3 is not parallel to the grating beam splitter 2, and a light receiving surface of the CCD camera 4 is parallel to a surface of the grating beam splitter 2.
Wherein, the object focusing lens 1 is used for collimating the reflected laser L1 reflected by the surface of the sample 10; the grating beam splitter 2 is configured to split the collimated reflected laser light into at least 3 split beams L2, and in this embodiment, the number of split beams L2 is 5. The image space focusing lens 3 is used for focusing all the split light beams L2 formed by splitting the grating beam splitter 2; the CCD camera 4 is used for receiving the spot image of the focused split light beam L2.
The image fitting computer 5 is electrically connected with the CCD camera 4, and is used for performing image fitting on the light spot image acquired by the CCD camera 4 and obtaining a light spot diameter change curve Lb.
The motion actuator 6 passes through the minimum point A of the light spot diameter change curve Lb min And a center point A mid Optionally, the sample 10 or the object focusing mirror 1 is moved until the minimum point A min And a center point A mid And (5) overlapping.
Wherein, in order to ensure that the collimated reflected laser light is guided to the grating beam splitter 2 for beam splitting, the system further comprises a light guide lens 7, and the light guide lens 7 is arranged between the object focusing lens 1 and the grating beam splitter 2.
After the structural arrangement of the system is adopted, the CCD camera 4 detects a series of light spots which are light spots of each split light beam L2. Wherein, because the image space focusing mirror 3 forms an included angle with the light receiving surface of the CCD camera 4, the focal plane formed by each beam of light splitting light L2 forms a corresponding included angle with the light receiving surface of the CCD camera 4. Specifically, the beam splitting light beam L2 generated by the grating beam splitter 2 is focused by the obliquely arranged image side focusing mirror 3, and is received by the CCD camera 4 with the vertically arranged light receiving surface, and the focal plane is inclined along with the image side focusing mirror 3 due to the inclination of the image side focusing mirror 3, so that an included angle exists between the beam splitting light beam L and the vertically arranged CCD camera 3; therefore, a series of light spots detected by the CCD camera have size difference, the position of the CCD camera 4 at the moment is the focal plane of the split light beam corresponding to the smallest light spot displayed by the CCD camera, and the rest split light beams L2 take the focal plane as a midpoint to form symmetrical defocusing states, wherein one side of the focal point is positive defocusing, the other side is negative defocusing, and the specific defocusing state depends on the included angle condition of the focusing mirror and the CCD photosensitive element.
The image fitting computer 5 is used for obtaining the light spot detected by the CCD camera 4 and fitting the light spot diameter change curve Lb. The light spotThe diameter change curve Lb must have a minimum point a min There also has to be a center point A mid . If the laser focus is positioned on the surface of the sample at this time, the fitted light spot diameter change curve Lb is in a completely symmetrical state, and the minimum point A of the light spot diameter change curve Lb min And a central point A mid And (5) overlapping. If the laser focus is in an out-of-focus state, the fitted light spot diameter change curve Lb is in an asymmetric state, and the minimum point A of the light spot diameter change curve Lb min And a central point A mid Are not coincident.
According to the detection result and distance, when the minimum value of the spot diameter change curve Lb does not coincide with the center point, the motion actuator 6 drives the object focusing lens 1 or the sample 10 to move (in actual use, the sample 10 can be driven to move, or the stage of the sample 10 can be driven to move, which all realize the movement of the sample), in this case, the sample 10 is preferably driven to move, and the minimum point a of the spot diameter change curve Lb is continuously detected min And a central point A mid Until the overlap is complete. Because the light spot diameter change curve Lb is obtained by fitting the symmetrical defocusing state, the position of the minimum value is used for calibrating the focus position, the precision is high, the light spot diameter change curve is not complex, the quick response can be obtained, and the high-precision real-time automatic focusing is realized.
Correspondingly, the beam-splitting automatic focusing method corresponding to the beam-splitting automatic focusing system comprises the following steps:
s1, arranging an object side focusing lens 1, a light guide lens 7, a grating beam splitter 2, an image side focusing lens 3 and a CCD camera 4 in sequence along a reflection light path, wherein the image side focusing lens 3 is not parallel to the grating beam splitter 2, a light receiving surface of the CCD camera 4 is parallel to a surface of the grating beam splitter 2, and the center of the grating beam splitter 2, the center of the image side focusing lens 3 and the center of the light receiving surface of the CCD camera 4 are collinear;
s2, collimating reflected laser reflected by the surface of the sample through an object focusing mirror 1;
s3, guiding the collimated reflected laser L1 to the grating beam splitter 2 through the light guide lens 7, and splitting the collimated reflected laser into five split beams L2 through the grating beam splitter 2;
s4, focusing all the split light beams L2 formed by splitting the grating beam splitter 2 through an image space focusing lens 3;
s5, receiving a spot image of the focused split light beam L2 through a CCD camera 4;
s6, performing image fitting on the spot images acquired by the CCD camera 4 through the image fitting computer 5 to obtain a spot diameter change curve Lb, and judging the minimum point A of the spot diameter change curve Lb min And a center point A mid Whether the focusing operation is coincident or not, if so, ending the focusing operation; if not, carrying out step S7;
and S7, driving the sample 10 to move through the motion executing mechanism 6, and repeating the steps S2-S6.
Up to the minimum point A min And a center point A mid Whether or not to coincide.
Example two
As shown in fig. 3, 4 and 5, the present embodiment provides a beam-splitting auto-focusing system, which has the same basic structure and operation principle as the first embodiment, and is different in that in this embodiment, the image focusing mirror 3 is parallel to the grating beam splitter 2, the light receiving surface of the CCD camera 4 is not parallel to the surface of the grating beam splitter 2, and the focusing condition of the light spot formed by the beam splitting auto-focusing system is shown in fig. 4.
At this time, the split light beam L2 generated by the grating beam splitter 2 is focused by the vertically arranged image-side focusing mirror 3 and received by the CCD camera 4 whose light receiving surface is obliquely arranged at the rear thereof, and an angle is formed between the focal plane in the vertical direction and the CCD camera 4 due to the inclination of the light receiving surface of the CCD camera 4.
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.
Claims (8)
1. The beam-splitting automatic focusing system is characterized by comprising an image fitting computer, a motion executing mechanism, and an object side focusing lens, a grating beam splitter, an image side focusing lens and a CCD camera which are sequentially arranged along a reflecting light path, wherein the center of the grating beam splitter, the center of the image side focusing lens and the center of a light receiving surface of the CCD camera are collinear;
the object focusing lens is used for collimating reflected laser reflected by the surface of the sample;
the grating beam splitter is used for splitting the collimated reflected laser into at least 3 beam splitting beams;
the image space focusing lens is used for focusing all the split light beams formed by splitting the grating beam splitter;
the CCD camera is used for receiving the spot image of the focused beam-splitting light beam, and an included angle exists between the light receiving surface of the CCD camera and the image space focusing lens;
the image fitting computer is electrically connected with the CCD camera and is used for performing image fitting on the light spot image acquired by the CCD camera and obtaining a light spot diameter change curve;
and the motion executing mechanism can selectively drive the sample or the object focusing lens to move according to the superposition condition of the minimum point and the center point of the light spot diameter change curve until the minimum point and the center point are superposed.
2. The beam-splitting autofocus system of claim 1, wherein said grating beam splitter is disposed parallel to said image-side focusing mirror.
3. The beam-splitting autofocus system of claim 1, wherein the light receiving surface of said CCD camera is disposed parallel to said grating beam splitter.
4. The beam-splitting autofocus system of claim 3, further comprising a light guide disposed between the object focusing mirror and the grating beam splitter for directing the collimated reflected laser light to the grating beam splitter for beam splitting.
5. A beam-splitting auto-focusing method, using the beam-splitting auto-focusing system of claim 1, comprising the steps of:
s1, arranging an object side focusing lens, a grating beam splitter, an image side focusing lens and a CCD camera in sequence along a reflection light path, wherein an included angle exists between a light receiving surface of the CCD camera and the image side focusing lens, and the center of the grating beam splitter, the center of the image side focusing lens and the center of the light receiving surface of the CCD camera are collinear;
s2, collimating reflected laser reflected by the surface of the sample through an object focusing mirror;
s3, splitting the collimated reflected laser into at least three split beams through a grating beam splitter;
s4, focusing all the split light beams formed by splitting the grating beam splitter through an image space focusing lens;
s5, receiving a spot image of the focused split beam through a CCD camera;
s6, performing image fitting on the spot image obtained by the CCD camera through an image fitting computer to obtain a spot diameter change curve, judging whether the minimum point and the center point of the spot diameter change curve coincide, and if so, ending focusing operation; if not, carrying out step S7;
and S7, driving the sample or the object focusing lens to move through the motion executing mechanism, and repeating the steps S2-S6.
6. The beam-splitting auto-focusing method according to claim 5, wherein the grating beam splitter is disposed in parallel with the image-side focusing mirror.
7. The beam-splitting auto-focusing method according to claim 5, wherein the light receiving surface of the CCD camera is disposed in parallel with the grating beam splitter.
8. The beam-splitting auto-focusing method according to claim 5, wherein step S1 further comprises disposing a light guide between the object focusing lens and the grating beam splitter; in step S3, before the collimated reflected laser beam is split into at least three split beams by the grating beam splitter, the method further includes guiding the collimated reflected laser beam to the grating beam splitter by a light guide lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210574173.9A CN115383287B (en) | 2022-05-24 | 2022-05-24 | Beam splitting type automatic focusing system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210574173.9A CN115383287B (en) | 2022-05-24 | 2022-05-24 | Beam splitting type automatic focusing system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115383287A CN115383287A (en) | 2022-11-25 |
| CN115383287B true CN115383287B (en) | 2024-01-16 |
Family
ID=84117157
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210574173.9A Active CN115383287B (en) | 2022-05-24 | 2022-05-24 | Beam splitting type automatic focusing system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115383287B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08201713A (en) * | 1995-01-20 | 1996-08-09 | Minolta Co Ltd | Laser beam scanning optical device |
| JPH09281384A (en) * | 1996-04-17 | 1997-10-31 | Citizen Watch Co Ltd | Autofocusing controller |
| US6677565B1 (en) * | 1998-08-18 | 2004-01-13 | Veeco Tucson Inc. | High speed autofocus and tilt for an optical imaging system |
| JP2006113198A (en) * | 2004-10-13 | 2006-04-27 | Olympus Corp | Focus detecting apparatus |
| KR20060108461A (en) * | 2005-04-13 | 2006-10-18 | 케이맥(주) | Apparatus for performing an auto-focus operation employing a pattern for the auto-focus operation and method for performing an auto-focus operation using the same |
| CN103209798A (en) * | 2010-09-30 | 2013-07-17 | 威孚莱有限公司 | Device and method for processing material by means of focused electromagnetic radiation |
| CN111381460A (en) * | 2020-04-29 | 2020-07-07 | 中国科学院光电技术研究所 | Measurement system and measurement method for focusing, leveling and precise alignment |
| CN112748510A (en) * | 2021-01-21 | 2021-05-04 | 浙江大学 | Scanning type automatic focusing method and device with automatic leveling function |
| CN113639637A (en) * | 2021-08-17 | 2021-11-12 | 吉林大学 | Method for detecting focus in femtosecond laser processing by using image sensor and application thereof |
| CN113927191A (en) * | 2021-11-29 | 2022-01-14 | 广东宏石激光技术股份有限公司 | Laser processing light beam quality monitoring system and method |
-
2022
- 2022-05-24 CN CN202210574173.9A patent/CN115383287B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08201713A (en) * | 1995-01-20 | 1996-08-09 | Minolta Co Ltd | Laser beam scanning optical device |
| JPH09281384A (en) * | 1996-04-17 | 1997-10-31 | Citizen Watch Co Ltd | Autofocusing controller |
| US6677565B1 (en) * | 1998-08-18 | 2004-01-13 | Veeco Tucson Inc. | High speed autofocus and tilt for an optical imaging system |
| JP2006113198A (en) * | 2004-10-13 | 2006-04-27 | Olympus Corp | Focus detecting apparatus |
| KR20060108461A (en) * | 2005-04-13 | 2006-10-18 | 케이맥(주) | Apparatus for performing an auto-focus operation employing a pattern for the auto-focus operation and method for performing an auto-focus operation using the same |
| CN103209798A (en) * | 2010-09-30 | 2013-07-17 | 威孚莱有限公司 | Device and method for processing material by means of focused electromagnetic radiation |
| CN111381460A (en) * | 2020-04-29 | 2020-07-07 | 中国科学院光电技术研究所 | Measurement system and measurement method for focusing, leveling and precise alignment |
| CN112748510A (en) * | 2021-01-21 | 2021-05-04 | 浙江大学 | Scanning type automatic focusing method and device with automatic leveling function |
| CN113639637A (en) * | 2021-08-17 | 2021-11-12 | 吉林大学 | Method for detecting focus in femtosecond laser processing by using image sensor and application thereof |
| CN113927191A (en) * | 2021-11-29 | 2022-01-14 | 广东宏石激光技术股份有限公司 | Laser processing light beam quality monitoring system and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115383287A (en) | 2022-11-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101856773B (en) | Focusing positioning method based on initial laser processing position and laser processing device | |
| CN102478700B (en) | Automatic focusing device and method | |
| US9752992B2 (en) | Variable image field curvature for object inspection | |
| CN112748510A (en) | Scanning type automatic focusing method and device with automatic leveling function | |
| CN111360395B (en) | Surface automatic tracking method and system for laser processing and storage medium | |
| CN201693290U (en) | Laser processing device | |
| WO2019159427A1 (en) | Camera module adjustment device and camera module adjustment method | |
| CN111390377A (en) | Surface automatic focusing method and system for laser processing and storage medium | |
| CN114007803B (en) | Laser processing device and method, chip transfer device and method | |
| CN115229330B (en) | Automatic focusing device and method for laser processing | |
| CN113231732A (en) | Laser processing system and control method thereof | |
| CN115383287B (en) | Beam splitting type automatic focusing system and method | |
| CN1518085B (en) | High-speed in-line electro-optics testing method and system for defects on chip | |
| KR102010818B1 (en) | Apparatus for capturing images of blood cell | |
| JP2001318302A (en) | Focus detecting device and autofocusing microscope | |
| KR20130073050A (en) | Laser machining device and calibration data generating method | |
| US9052500B2 (en) | Fast pinhole changer for confocal microscopy or spatial filter | |
| KR100696396B1 (en) | Laser beam processing apparatus | |
| KR101846239B1 (en) | Alignment system and method for freeform optics | |
| JP2019163946A (en) | Noncontact surface profile measurement device | |
| JP2000098256A (en) | Aiming device for microscope | |
| WO2023127261A1 (en) | Auto-focus device | |
| US8093540B2 (en) | Method of focus and automatic focusing apparatus and detecting module thereof | |
| CN220526185U (en) | Wafer direct-writing machining device | |
| JP2005284118A (en) | Automatic focusing control device and automatic focusing control method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |