CN105301768B - Lens vibrating type laser scanning system - Google Patents

Abstract

The invention discloses a galvanometer-type laser scanning system. The system sequentially includes along the axis: a laser, a focusing lens, a first galvanometer, a second galvanometer and a scanning surface. The focusing lens includes a plano-concave mirror and a scanning surface. Convex lens, the plano-concave mirror includes oppositely arranged planes and concave surfaces, the convex lens includes oppositely arranged first convex surfaces and second convex surfaces, the convex lens is fixedly arranged, and the plano-concave mirror is fixedly installed on parallel lines that can be along the axis on a translation stage that moves horizontally. The galvanometer laser scanning system of the present invention has a simple structure, and the installation and adjustment error of the system is small; the focusing lens has no real focus, so that the galvanometer laser scanning system can maintain a relatively low temperature.

Description

Galvanometer Laser Scanning System

technical field

The invention relates to the technical field of optical engineering, in particular to a vibrating mirror laser scanning system.

Background technique

Laser scanning technology is a technology that can precisely control the pointing of laser beams. It has been widely used in optoelectronic medical treatment, laser processing, space laser communication, laser radar, remote sensing and measurement, adaptive optics and other fields. In the field of laser processing and laser compliance, galvanometer laser scanning technology has been used. In order to ensure the accuracy of laser processing, the laser needs to be focused before reaching the processing surface to ensure good focusing characteristics on the working surface. According to the position of the focusing system, it can be divided into two types of focusing: the front focus of the galvanometer and the focus after the galvanometer. Way.

Patent No. 200320116330.4 in the prior art discloses a galvanometer-type front-focus laser scanning system, including a laser, a focusing module, an X-axis scanning head, and a Y-axis scanning head. The laser beam passes through the focusing module composed of three combined lenses, and reaches the focus working plane through the X-axis scanning head and the Y-axis scanning head. The lens is composed of a full-digital AC servo motor shaft with a limit device; the control system controls the movement of the lens on the X-axis and Y-axis through two full-digital AC servo motor controllers to realize two-dimensional scanning. After adding a dynamic focus module, it can ensure good focus characteristics on the scanning surface. However, this scanning system uses three lenses to achieve dynamic focusing, and the optical design and focusing model are relatively complicated. Too many lenses will increase the errors caused by processing and assembly, which will affect the focusing effect. In addition, the system described in this invention uses a focusing lens. In addition to the scanning surface, there is also a focus point in the optical path in the system. The focus point of the high-energy laser beam will cause excessive temperature and increase the risk of equipment damage.

In addition, patent 200810197661.2 in the prior art discloses a galvanometer post-focus scanning system, including a laser, a beam expander, an x-axis scanning galvanometer, a y-axis scanning galvanometer, a scanning focusing lens, a z-axis moving mechanism and a control system. The laser emits a laser beam. After being enlarged and collimated by the beam expander, the laser beam directly enters the x-axis scanning galvanometer and y-axis scanning galvanometer. The control system controls the z-axis moving mechanism to drive the scanning focusing lens to move up and down in the z-axis direction. Adjust the position of the laser focus point in the z-axis direction, and realize the three-dimensional processing function through the scanning focusing lens fixed on the z-axis moving mechanism that can move up and down along the z-axis direction. This system uses the F-theta lens as the focusing lens, which can ensure the focusing characteristics of the laser on the working surface within a certain range. However, on the one hand, the size of the F-theta lens cannot be made very large; on the other hand, the focusing effect of this focusing method at the edge of the F-theta lens becomes worse, and large-format laser scanning cannot be realized.

Therefore, in view of the above technical problems, it is necessary to provide a new vibrating mirror laser scanning system.

Contents of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a galvanometer-type laser scanning system focused in front of the galvanometer.

In order to achieve the above object, the technical solutions provided by the embodiments of the present invention are as follows:

A galvanometer-type laser scanning system, the system sequentially includes along the axis: a laser, a focus lens, a first galvanometer, a second galvanometer and a scanning surface, the focus lens includes a plano-concave mirror and a convex lens, the The plano-concave mirror includes oppositely arranged planes and concave surfaces, and the convex lens includes oppositely arranged first convex surfaces and second convex surfaces. on stage.

As a further improvement of the present invention, the translation platform includes a first translation platform and a second translation platform, the plano-concave mirror is fixedly installed on the first translation platform, and the first translation platform is fixedly installed on the second translation platform .

As a further improvement of the present invention, the first translation platform is an automatic translation platform, and the second translation platform is a manual translation platform.

As a further improvement of the present invention, a laser beam expander system is provided between the laser and the focusing lens.

As a further improvement of the present invention, the curvature radii of the first convex surface and the second convex surface of the convex lens are equal and greater than the curvature radius of the concave surface of the plano-concave mirror.

As a further improvement of the present invention, the distance between the concave surface of the plano-concave mirror and the first convex surface of the convex lens is 10-100 mm.

As a further improvement of the present invention, the distance between the plane and the concave surface of the plano-concave mirror is 1-10 mm, and the distance between the first convex surface and the second convex surface of the convex lens is 1-10 mm.

As a further improvement of the present invention, the system also includes a control unit connected to the displacement platform, and the control unit includes:

The computer is used to control the displacement of the plano-concave mirror through the drive motor of the displacement platform in the displacement platform;

A scan head controller, connected to the computer, used to receive vibration angle information of the vibrating mirror;

The driving motor is connected with the scanning head controller and is used to drive the first oscillating mirror and/or the second oscillating mirror to oscillate according to the oscillating angle information.

As a further improvement of the present invention, the scan head controller includes a first scan head controller and a second scan head controller, respectively used to receive the first swing angle information of the first oscillating mirror and the second oscillating angle information of the second oscillating mirror. swing angle information.

As a further improvement of the present invention, the drive motor includes a first drive motor connected to the first scan head controller and a second drive motor connected to the second scan head controller, the first drive motor is connected to the first vibrator The mirror is connected to drive the first oscillating mirror to oscillate according to the first oscillating angle information, and the second drive motor is connected to the second oscillating mirror to drive the second oscillating mirror to oscillate based on the second oscillating angle information.

The present invention has the following beneficial effects:

The galvanometer laser scanning system has a simple structure, and the installation and adjustment error of the system is small;

The focusing lens has no real focus so that the galvanometer laser scanning system can keep relatively low temperature;

The position of the plano-concave mirror is changed by the electric translation stage to automatically adjust the focal length of the optical system to ensure that there is a good focused spot on the entire scanning surface, and it can complete the precision processing of large-scale format;

The position of the plano-concave mirror can be adjusted by the manual shift stage to make the system work in different working distances and working formats.

Description of drawings

FIG. 1 is a schematic structural diagram of a galvanometer-type laser scanning system according to a specific embodiment of the present invention.

FIG. 2 is a block diagram of a control unit in a galvanometer-type laser scanning system according to a specific embodiment of the present invention.

detailed description

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

The invention discloses a vibrating mirror laser scanning system, which sequentially includes a laser, a focusing lens, a first vibrating mirror, a second vibrating mirror and a scanning surface along the axis, the focusing lens includes a plano-concave mirror and a convex lens, and the plano-concave mirror The convex lens includes a first convex surface and a second convex surface opposite to each other, the convex lens is fixedly arranged, and the plano-concave mirror is fixedly installed on a displacement platform that can move horizontally along the parallel line of the axis.

Referring to Fig. 1, in a specific embodiment of the present invention, the vibrating mirror laser scanning system includes: carbon dioxide laser 1, beam expander lens 2, plano-concave mirror 3, convex lens 4, X vibrating mirror 5, Y vibrating mirror 6 , a scanning surface 7, a motorized translation platform 8 and a manual translation platform 9.

The beam emitted by the carbon dioxide laser 1 is expanded through the beam expander lens 2, and the expanded laser beam passes through the focusing lens composed of a plano-concave mirror 3 and a convex lens 4, and then enters the center of the X galvanometer 5, and the X galvanometer 5 The laser beam is reflected onto the Y oscillating mirror 6 , and the Y oscillating mirror 6 then reflects the laser beam onto the scanning surface 7 . The plano-concave mirror is installed on the electric translation platform 8, the initial installation position is fixed, and the electric translation platform is installed on the manual translation platform 9. The motorized translation stage can automatically control the plano-concave mirror 3 to move toward the convex lens 4, and adjust the focal length of the entire system, so that each scanning point on the scanning surface 7 is exactly the focus point of the laser beam. The electric translation platform 8 is installed on the manual translation platform 9, and the distance between the electric translation platform 8 and the manual translation platform 9 can be manually adjusted during the initial installation, so that there are different distances between the plano-concave mirror 3 and the convex lens 4, which can correspond to Different initial focal lengths.

In this embodiment, the plano-concave mirror 3 and the convex lens 4 together constitute the focusing lens, the purpose of which is to optimize the existing dynamic focus module optical system. The structure of the focusing lens is simpler, and the focusing lens has no real focus so that the structure is not easy to generate high temperature .

The plano-concave mirror 3 includes a flat surface and a concave surface opposite to each other, and the convex lens 4 includes a first convex surface and a second convex surface opposite to each other. The convex lens 4 is fixedly arranged, and the plano-concave mirror 3 is movable on the axis. The laser beam is incident from the plane of the plano-concave mirror 3, passes through the concave surface of the plano-concave mirror and the first convex surface of the convex lens, and exits from the second convex surface of the convex lens 4.

Wherein, in this embodiment, the materials used for the plano-concave mirror 3 and the convex lens 4 are the same, both being zinc selenide. The curvature radii of the first convex surface and the second convex surface of the convex lens 4 are equal, and larger than the curvature radius of the concave surface of the plano-concave mirror 3 .

Further, the distance between the concave surface of the plano-concave mirror 3 and the first convex surface of the convex lens 4 is 10-100mm, and the distance between the plane of the plano-concave mirror 3 and the concave surface is 1-10mm, the first convex surface of the convex lens 4 and The distance between the second convex surfaces is 1-10 mm.

Specifically, in a specific embodiment of the present invention, the distance between the plane and the concave surface of the plano-concave mirror 3 is 5mm, and the distance between the first convex surface and the second convex surface of the convex lens 4 is 5mm. The radius of curvature of the concave surface is 110.94 mm, the radius of curvature of the first convex surface and the second convex surface of the convex lens 4 are both 368.78 mm, and the distance between the concave surface of the plano-concave mirror 3 and the first convex surface of the convex lens 4 is 50 mm.

When the focusing lens works, the convex lens 4 is fixed, and the plano-concave mirror 3 can move towards the direction of the convex lens 4 under the driving of the driving mechanism. Assuming that the amount of movement is Z, the focal length of the entire focusing lens can be changed.

In this embodiment, the focusing length when the light wavelength is 10.64 μm and the initial focal length is 750 mm is:

Among them, ΔS is the focusing length, and Z is the displacement of the plano-concave mirror.

The translation platform in this embodiment includes an electric translation platform 8 and a manual translation platform 9 , the plano-concave mirror 3 is fixedly mounted on the electric translation platform 8 , and the electric translation platform 8 is fixedly installed on the manual translation platform 9 . The electric displacement stage 8 is controlled by a computer, and when the operator wants to achieve different working heights and working ranges, he can adjust the position of the plano-concave mirror 3 through the manual moving stage, and use the principle of optical levers to achieve different working heights and working ranges, or the environment When various conditions such as temperature affect the optical system, the position of the plano-concave mirror can be manually adjusted to focus the light on the working surface.

In addition, the galvanometer-type laser scanning system in this embodiment also includes a control unit. Specifically, as shown in FIG. 2, the control unit includes:

The computer 10 is used to control the displacement of the plano-concave mirror 3 through the automatic displacement table 8, and is also used to calculate the required swing angle information of the X vibrating mirror 5 and the Y vibrating mirror 6;

The scan head controller, including the X-axis scan head controller 11 and the Y-axis scan head controller 13, is connected with the computer 10 respectively, and is used to receive the first swing information required by the X vibrating mirror 5 and the required first swing information of the Y vibrating mirror 6. second swing information;

Drive motors, including X-axis drive motor 12 and Y-axis drive motor 14, are connected with X-axis scanning head controller 11 and Y-axis scanning head controller 13 respectively, and are respectively used to drive X vibrating mirror 5 and Y vibrating mirror 6 with the second The first swing angle information and the second swing information perform swing.

Specifically, as shown in Figure 2, the laser beam passes through the galvanometer system to complete the X-Y plane scanning. For large-format plane scanning, a three-dimensional objective lens rear galvanometer scanning system with a dynamic focusing lens is used. The computer 10 calculates the required swing angles of the X and Y vibration mirrors from the scanning coordinates. The computer 10 controls the full digital AC X-axis drive motor 12 of the X-axis scan head through the X-axis scan head controller 11, and is driven by the X-axis drive motor 12. The X oscillating mirror 5 swings at a corresponding angle, and the Y-axis scanning head controller 13 controls the all-digital AC Y-axis drive motor 14 of the Y-axis scan head, and the Y-axis drive motor 14 drives the Y galvanometer to swing at a corresponding angle.

Under the control of the corresponding drive motors, the X galvanometer and Y galvanometer reflect the laser beam to the predetermined X and Y coordinate points on the working surface. The computer can also calculate the defocus error of the system and the moving distance of the plano-concave mirror 3 to the direction of the convex lens by scanning the coordinates, and directly control the motorized stage drive motor 15 of the motorized stage 8 to drive the plano-concave mirror to move the corresponding distance.

As can be seen from the above technical solutions, the present invention has the following advantages:

The galvanometer laser scanning system has a simple structure, and the installation and adjustment error of the system is small;

The focusing lens has no real focus so that the galvanometer laser scanning system can keep relatively low temperature;

The position of the plano-concave mirror is changed by the electric translation stage to automatically adjust the focal length of the optical system to ensure that there is a good focused spot on the entire scanning surface, and it can complete the precision processing of large-scale format;

The position of the plano-concave mirror can be adjusted by the manual shift stage to make the system work in different working distances and working formats.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (9)

1. A vibrating mirror type laser scanning system, characterized in that, the system includes along the axis: a laser, a focusing lens, a first vibrating mirror, a second vibrating mirror and a scanning surface, and the focusing lens includes a plano-concave A mirror and a convex lens, the plano-concave mirror includes a plane and a concave surface oppositely arranged, the convex lens includes a first convex surface and a second convex surface oppositely arranged, the convex lens is fixedly arranged, and the plano-concave mirror is fixedly installed on a On a displacement stage that parallel lines move horizontally; the curvature radii of the first convex surface and the second convex surface in the convex lens are equal, and larger than the curvature radius of the concave surface in the plano-concave mirror. 2. The galvanometer-type laser scanning system according to claim 1, wherein the displacement stage comprises a first displacement stage and a second displacement stage, and the plano-concave mirror is fixedly mounted on the first displacement stage, and the The first displacement platform is fixedly installed on the second displacement platform. 3 . The galvanometer laser scanning system according to claim 2 , wherein the first translation stage is an automatic translation stage, and the second translation stage is a manual translation stage. 4 . 4. The galvanometer-type laser scanning system according to claim 1, wherein a laser beam expander system is provided between the laser and the focusing lens. 5 . The vibrating mirror laser scanning system according to claim 1 , wherein the distance between the concave surface of the plano-concave mirror and the first convex surface of the convex lens is 10-100 mm. 6. The galvanometer-type laser scanning system according to claim 5, wherein the distance between the plane and the concave surface of the plano-concave mirror is 1-10 mm, and the distance between the first convex surface and the second convex surface of the convex lens is The distance is 1-10mm. 7. The galvanometer-type laser scanning system according to claim 1, wherein the system further comprises a control unit connected to the displacement stage, and the control unit comprises: The computer is used to control the displacement of the plano-concave mirror through the drive motor of the displacement platform in the displacement platform; A scan head controller, connected to the computer, used to receive vibration angle information of the vibrating mirror; The driving motor is connected with the scanning head controller and is used to drive the first oscillating mirror and/or the second oscillating mirror to oscillate according to the oscillating angle information. 8. The vibrating mirror laser scanning system according to claim 7, wherein the scanning head controller comprises a first scanning head controller and a second scanning head controller, which are respectively used to receive the The first swing angle information and the second swing angle information of the second vibrating mirror. 9. The galvanometer laser scanning system according to claim 8, wherein the drive motor comprises a first drive motor connected to the first scan head controller and a second drive motor connected to the second scan head controller A driving motor, the first driving motor is connected with the first oscillating mirror and drives the first oscillating mirror to oscillate with the first oscillating angle information, and the second driving motor is connected with the second oscillating mirror and drives the second oscillating mirror to oscillate at the second The angle information is oscillated.