CN117215050B - A galvanometer scanning system with simplified flat-field lens - Google Patents
A galvanometer scanning system with simplified flat-field lens Download PDFInfo
- Publication number
- CN117215050B CN117215050B CN202311259767.1A CN202311259767A CN117215050B CN 117215050 B CN117215050 B CN 117215050B CN 202311259767 A CN202311259767 A CN 202311259767A CN 117215050 B CN117215050 B CN 117215050B
- Authority
- CN
- China
- Prior art keywords
- lens
- flat field
- field lens
- lens group
- auxiliary
- 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
- 230000003287 optical effect Effects 0.000 claims abstract description 21
- 238000007639 printing Methods 0.000 claims abstract description 15
- 238000010146 3D printing Methods 0.000 abstract description 3
- 238000013041 optical simulation Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 5
- 238000005452 bending Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Landscapes
- Lenses (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Laser Beam Processing (AREA)
Abstract
The invention relates to a galvanometer scanning system for simplifying a flat field lens, which belongs to the technical field of laser 3D printing equipment and comprises an auxiliary lens, a scanning galvanometer and a flat field lens group which are sequentially arranged on a laser beam path, wherein the focal length of the auxiliary lens is f1, the distance between the auxiliary lens and the scanning galvanometer is L1, the maximum inclination angle light beam optical path between the scanning galvanometer and the flat field lens group is L2, the focal length of the auxiliary lens meets the following formula f1< L1+L2, and the flat field lens group comprises at least 1 convex lens. After the light beam passes through the auxiliary lens, the image distance of the inclined light beam becomes longer than that of the light beam on the optical axis, so that the length of the light beam between the flat field lens group and the printing working surface is longer than the focal length of the flat field lens group, the image field after the flat field lens group is changed into a planar image field, the purpose of changing the bent image field into the planar image field is achieved by not increasing the number of lenses in the flat field lens group, the structure of the flat field lens group is simplified, and the volume is reduced.
Description
Technical Field
The invention belongs to the technical field of laser 3D printing equipment, and particularly relates to a galvanometer scanning system for simplifying a flat field lens.
Background
The galvanometer scanning processing is widely applied to the industries of laser drilling, cutting, welding, 3D printing and the like, and the principle is that the galvanometer is adopted to reflect laser beams so as to scan and print images on a printing working surface. The current laser scanning focusing mode includes a front focusing galvanometer (PRE-SCAN) mode and a rear focusing galvanometer (POST-SCAN) mode, wherein the front focusing galvanometer focuses after scanning, and the rear focusing galvanometer focuses before scanning.
In the front focusing scheme, laser beams firstly pass through a collimating lens and a beam expander, then pass through a dynamic focusing lens capable of moving in real time, and then reflect laser through a galvanometer, so that scanning and printing work of the laser on a printing working surface is realized. The scheme needs to use a program compensation algorithm to control the focusing lens in real time and match the position compensation focal length of the galvanometer scanning to realize dynamic focusing, so that the laser beam can be imaged on the printing working surface in real time. Dynamic focusing devices require lens back and forth motion to compensate for focal length more than 100 hundred million times during a year of operation, and therefore have very high requirements for stability of voice coil motors and linear guides. With the actual performance of current industry products, front-focusing dynamic focusing schemes are less stable than rear-focusing flat-field lens schemes. In addition, the front focusing system is limited by the principle of an optical system, and when scanning a printing pattern, the beam vertically scans the center position of the pattern and the beam obliquely scans the edge position of the pattern, and the spot deformation amount thereof is close to twice that of the rear focusing system, so that the quality of part edge printing is poorer.
The back focusing vibrating mirror mode is that laser beam emitted by the laser passes through the collimating mirror and the beam expanding mirror, then passes through the scanning vibrating mirror and finally passes through the field lens (also called as f-theta flat field lens and f-theta field lens) to scan to the processing surface. The scanning galvanometer realizes deflection of the laser beam by changing the reflection angles of the two reflectors in the X, Y axial direction, and further controls the laser beam to move according to a specified scanning path. The f-theta flat field lens changes the position of an imaging light beam on the premise of not changing the optical characteristics of an optical system, and realizes uniform focusing of light spots on the whole processing surface.
The F-Theta flat field lens used in the back focusing mainly realizes two functions, namely, correcting the bending image fields of laser focuses with different scanning angles in the front focusing system into a plane image field, and changing the relation between the scanning angle and the scanning position of a printing working surface from F/tan (Theta) to F/Theta, namely, the scanning angle is in direct proportion to the light spot position. In the effect of an F-Theta flat field lens in practical application, the effect of correcting a bending image field is more important, and a motor and a driver for focusing can be omitted for the function, so that a control system is simpler.
The F-Theta flat field lens has a structure as shown in the Chinese patent application publication number CN101846791A, CN114994866A and the issued publication number CN203909385U, and because the image field curvature needs to be corrected with a large scanning angle of the galvanometer, the high-precision F-Theta flat field lens optical lens usually comprises more than 4 lenses, which results in a complex structure and a large volume of the F-Theta flat field lens.
Disclosure of Invention
The invention aims to provide a galvanometer scanning system for simplifying a flat field lens, which aims to solve the problems of complex structure, large volume and the like of an F-Theta flat field lens used in the existing back focusing galvanometer scanning system.
In order to solve the technical problems, the invention adopts the following technical scheme:
The invention relates to a galvanometer scanning system for simplifying a flat field lens, which comprises an auxiliary lens, a scanning galvanometer and a flat field lens group which are sequentially arranged on a laser beam path, wherein the focal length of the auxiliary lens is f1, the distance between the auxiliary lens and the scanning galvanometer is L1, the maximum inclination angle light beam optical path between the scanning galvanometer and the flat field lens group is L2, the focal length of the auxiliary lens meets the following formula of f1< L1+L2, and the flat field lens group comprises at least 1 convex lens.
Preferably, the auxiliary lens is a concave lens, and the focal length f1 of the auxiliary lens is less than 0.
Preferably, the auxiliary lens is a convex lens, and the focal length of the auxiliary lens is 0< f1< L1+L2.
Preferably, the flat field lens group comprises 1-2 convex lenses.
Preferably, the flat field lens group comprises 2 convex lenses, and the 2 convex lenses are arranged in parallel at intervals.
Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:
The invention relates to a vibrating mirror scanning system for simplifying a flat field lens, which is an improvement on a rear focusing vibrating mirror scanning system, wherein an auxiliary lens is arranged in front of a scanning vibrating mirror, the focal length f1 of the auxiliary lens, the distance L1 between the auxiliary lens and the scanning vibrating mirror and the maximum inclination angle light beam optical path L2 between the scanning vibrating mirror and a flat field lens group meet f1< L1+L2, after a light beam penetrates through the auxiliary lens, the image distance of the inclined light beam becomes longer than that of the light beam on an optical axis, so that the light beam length between the flat field lens group and a printing working surface is longer than the focal length of the flat field lens group, the image field after the flat field lens group is changed into a plane image field, the purpose of changing the bent image field into the plane image field is achieved without increasing the number of lenses in the flat field lens group, the structure of the flat field lens group is simplified, and the volume is reduced.
Drawings
FIG. 1 is a block diagram of a galvanometer scanning system of a simplified flat field lens in accordance with the present invention;
FIG. 2 is a simplified optical path schematic diagram of a galvanometer scanning system of a simplified flat field lens according to the present invention;
FIG. 3 is an optical simulation of the use of a monolithic flat field lens without an auxiliary lens;
FIG. 4 is an optical simulation of the use of a monolithic flat field lens with the auxiliary lens set in example 2;
FIG. 5 is an optical simulation of the use of a monolithic flat field lens with the auxiliary lens set in example 3;
FIG. 6 is an optical simulation of the use of a monolithic flat field lens with the auxiliary lens set in example 4;
FIG. 7 is a graph of distortion of the F/θ relationship in example 4.
Reference numeral 1-laser beam, 2-auxiliary lens, 3-scanning galvanometer, 4-flat field lens group, 41-convex lens and 5-printing working surface.
Detailed Description
The following detailed description of the present invention clearly and fully describes the technical solutions of the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
For the scanning system without the auxiliary lens 2 and with the flat field lens group 4 of 1 convex lens, the incident laser beam is the collimated laser beam 1 with the diameter of 20mm, the scanning angle of the laser beam 1 reflected by the scanning vibrating mirror 3 is +/-20 degrees, the wavelength is 1064nm, the working distance is 600mm, the flat field lens design is carried out by using the single convex lens 41, the final optical simulation optimization result is shown in fig. 3, and the optical path parameters are shown in table 1:
TABLE 1 optical path parameter map for the case where no auxiliary lens is provided and the flat field lens group is 1 convex lens
It can be seen that, if the single lens is used to correct the curved image field into a planar image field, the single lens has limited correction of the curvature of the image field, and finally cannot correct the curved image field into a planar image field, and the curvature radius of the corrected image field still has 860mm. In this regard, in the present embodiment, the auxiliary lens 2 is provided in front of the scanning galvanometer 3 while maintaining the design of the flat field lens group 4 with the single convex lens 41, so as to improve the scanning system.
Example 2
Referring to fig. 1 and 2, this embodiment is a galvanometer scanning system based on one of the modifications of embodiment 1, and relates to a simplified flat field lens, which includes an auxiliary lens 2, a scanning galvanometer 3, and a flat field lens group 4 sequentially disposed on the path of a laser beam 1. The laser beam 1 is a collimated parallel beam, and the collimation is realized by a collimating mirror, which is not shown in the drawings because the laser beam 1 does not belong to the protection scope of the invention in the prior art. The focal length of the auxiliary lens 2 is f1, the distance between the auxiliary lens 2 and the scanning galvanometer 3 is L1, the maximum inclination angle light beam path between the scanning galvanometer 3 and the flat field lens group 4 is L2, the maximum inclination angle light beam path between the flat field lens group 4 and the printing working surface 5 is L3, and the following relation is provided according to a lens imaging formula: Referring to embodiment 1, for oblique light beams, the auxiliary lens 1 needs to make the oblique light beam image distance longer than that of the light beam on the optical axis on the basis of embodiment 1, i.e., L3> f2 to make the image field behind the flat field lens group 4 planar, and therefore the above formula must be satisfied: thus, the focal length of the auxiliary lens satisfies the following formula of f1< L1+L2.
In the present embodiment, the auxiliary lens 2 is a concave lens with a focal length f1<0, and the plano-field lens group is 1 convex lens 41 for plano-field design. The optical simulation diagram of the system is shown in fig. 4, and the optical path parameters are shown in table 2:
TABLE 2 optical path parameter map of scanning System according to example 2
Thus, the correction capability of the plano-field lens group 4 for the curved image field is greatly improved after the single concave lens sheet is added to the position of the auxiliary lens 2, and the curvature of the image field can be perfectly corrected by using the single convex lens 41 as the plano-field lens group 4.
Example 3
In this embodiment, the auxiliary lens 2 is a convex lens with focal length 0< f1< L1+L2, and the flat field lens group 4 is designed by 1 convex lens 41, the optical simulation diagram is shown in FIG. 5, and the optical path parameters are shown in Table 3:
TABLE 3 optical path parameter map of scanning System according to example 3
The flat field lens group 4 can also achieve perfect correction of field curvature using the single convex lens 41 after adding a single convex lens sheet at the position of the auxiliary lens 2 in the present embodiment, but the capability of correcting geometrical aberration is inferior to that of the concave lens in embodiment 2, and the auxiliary lens 2 is more recommended to use a concave lens or a concave lens group in practical use.
Example 4
In this embodiment, the auxiliary lens 2 is a concave lens with focal length satisfying f1<0, and the flat field lens group 4 is designed by using 2 convex lenses 41, the optical simulation diagram is shown in fig. 6, and the optical path parameters are shown in table 4:
TABLE 4 optical path parameter map of scanning System according to example 4
In this embodiment, a single concave lens is added at the position of the auxiliary lens 2, and the flat field lens group 4 uses two convex lenses 41, so that not only the correction of a curved image field is realized, but also the distortion correction of the F/θ relationship is realized, and the use requirement is also met. Fig. 7 is a distortion graph of the F/θ relationship in embodiment 4, in which the distortion value of the F/θ relationship in the whole field of view is not more than ±0.01%, the embodiment is a 360 x 360mm lens for printing, and in the whole field of view, the maximum deviation of the distortion of the image and the F/θ relationship at the printing working surface is not more than 180mm x 0.01% =18 um, so as to satisfy the precision requirement of laser scanning printing on the pattern.
The present invention has been described in detail with reference to the embodiments, but the description is only the preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. All equivalent changes and modifications within the scope of the present invention should be considered as falling within the scope of the present invention.
Claims (5)
1. A vibrating mirror scanning system for simplifying a flat field lens is characterized by comprising an auxiliary lens, a scanning vibrating mirror and a flat field lens group which are sequentially arranged on a laser beam path, wherein the focal length of the auxiliary lens is f1, the distance between the auxiliary lens and the scanning vibrating mirror is L1, the maximum inclination angle beam optical path between the scanning vibrating mirror and the flat field lens group is L2, the focal length of the auxiliary lens satisfies the following formula that f1< L1+L2, after a laser beam passes through the auxiliary lens, the image distance of the inclined beam becomes longer than that of the beam on an optical axis, the beam length between the flat field lens group and a printing working surface is larger than that of the flat field lens group, and then the image field after the flat field lens group is changed into a plane image field, and the flat field lens group comprises at least 1 convex lens.
2. The galvanometer scanning system of the simplified flat field lens as set forth in claim 1, wherein the auxiliary lens is a concave lens, and a focal length f1 of the auxiliary lens is less than 0.
3. The galvanometer scanning system of the simplified flat field lens as set forth in claim 1, wherein the auxiliary lens is a convex lens, and a focal length of the auxiliary lens is 0< f1< L1+L2.
4. The galvanometer scanning system of the simplified flat field lens as set forth in claim 1, wherein the flat field lens group comprises 1-2 convex lenses.
5. The galvanometer scanning system of the simplified flat field lens as set forth in claim 1, wherein the flat field lens group comprises 2 convex lenses, and the 2 convex lenses are arranged in parallel at intervals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311259767.1A CN117215050B (en) | 2023-09-27 | 2023-09-27 | A galvanometer scanning system with simplified flat-field lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311259767.1A CN117215050B (en) | 2023-09-27 | 2023-09-27 | A galvanometer scanning system with simplified flat-field lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117215050A CN117215050A (en) | 2023-12-12 |
| CN117215050B true CN117215050B (en) | 2025-04-15 |
Family
ID=89035168
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311259767.1A Active CN117215050B (en) | 2023-09-27 | 2023-09-27 | A galvanometer scanning system with simplified flat-field lens |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117215050B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5153767A (en) * | 1990-03-01 | 1992-10-06 | Canon Kabushiki Kaisha | F-θ lens system and laser scanner using the same |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3445092B2 (en) * | 1996-03-29 | 2003-09-08 | キヤノン株式会社 | Scanning optical device |
| US7108691B2 (en) * | 2002-02-12 | 2006-09-19 | Visx, Inc. | Flexible scanning beam imaging system |
| CN102079176A (en) * | 2009-11-28 | 2011-06-01 | 深圳市大族激光科技股份有限公司 | Laser marking machine |
| CN115416299B (en) * | 2022-11-04 | 2023-03-24 | 杭州爱新凯科技有限公司 | Need not to remove laser galvanometer 3D printing apparatus of focusing |
-
2023
- 2023-09-27 CN CN202311259767.1A patent/CN117215050B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5153767A (en) * | 1990-03-01 | 1992-10-06 | Canon Kabushiki Kaisha | F-θ lens system and laser scanner using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117215050A (en) | 2023-12-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5561544A (en) | Laser scanning system with reflecting optics | |
| JPH0627904B2 (en) | Laser beam scanning optics | |
| CN104379296B (en) | Laser processing device | |
| US4620768A (en) | Optical scanning system | |
| US5828481A (en) | Mid-objective laser scanner | |
| US4930850A (en) | Scanning optical system for use in laser beam printer | |
| CN117148565B (en) | Front focusing galvanometer scanning system and scanning method with adjustable multiplying power | |
| CN117215050B (en) | A galvanometer scanning system with simplified flat-field lens | |
| CN216576047U (en) | Astigmatism correction device and laser processing system | |
| CN114879214A (en) | An optical shaping module, device and lidar system | |
| US4953926A (en) | Scanning optical system for use in a laser beam printer | |
| CN113459678A (en) | Laser 3D printer edge light spot area compensation method | |
| CN117103684B (en) | Scanning system for reducing inertia of vibrating mirror with long working distance | |
| US5327280A (en) | Scanning optical system | |
| CN115502550B (en) | Large relative aperture telecentric scanning field lens system | |
| JP5307148B2 (en) | Scanning optical device | |
| CN117048055B (en) | Adjusting device for printing breadth and precision of vibrating mirror of scanning system | |
| JP2657381B2 (en) | Light flux adjusting method for scanning optical device | |
| CN221993699U (en) | Transmission type cylindrical optical system | |
| CN112415739B (en) | Laser scanning optical system with variable working distance | |
| JPH11271657A (en) | Optical scanning device | |
| JP2678495B2 (en) | Scanning optical system such as laser printer | |
| JP3594821B2 (en) | Scanning optical system | |
| JP3538273B2 (en) | Scanning lens | |
| JP2966561B2 (en) | Scanning optical system |
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 |