CN217096199U

CN217096199U - Laser cutting device

Info

Publication number: CN217096199U
Application number: CN202220457277.7U
Authority: CN
Inventors: 吴春洲; 邹志新; 高阳; 江新; 刘昂
Original assignee: Changsha Lubang Photoelectric Technology Co ltd
Current assignee: Changsha Lubang Photoelectric Technology Co ltd
Priority date: 2022-03-04
Filing date: 2022-03-04
Publication date: 2022-08-02
Anticipated expiration: 2032-03-04

Abstract

The utility model provides a laser cutting device, includes casing, quarter wave plate and lens, and quarter wave plate and lens are all installed in the casing, and the lens is including the diffraction cone lens, first lens and the second lens that arrange in proper order, and wherein diffraction cone lens is closer to quarter wave plate, and first lens and second lens constitute a two telecentric systems. The utility model discloses a laser cutting device can be used for the transparent material processing of different thickness, and the system is simple, and is with low costs, and the assembly is simple.

Description

Laser cutting device

Technical Field

The utility model relates to a laser beam machining equipment technical field, concretely relates to laser cutting device.

Background

Laser cutting belongs to one of thermal cutting methods, and is characterized in that a workpiece is irradiated by utilizing a focused high-power-density laser beam, so that the irradiated material is quickly melted, vaporized and ablated or reaches a burning point, and meanwhile, a high-speed airflow coaxial with the laser beam is used for blowing off molten substances, so that the workpiece is cut off. Compared with other conventional processing methods, the laser cutting technology has the advantages of high precision, narrow cutting seam, smooth cutting surface, high speed, no damage to a workpiece, good adaptability, no influence of the hardness of a cut material and the appearance of the workpiece, and can cut and process non-metals such as plastics, wood, PVC, leather, textiles, organic glass and the like, so the laser cutting technology is widely popularized and applied.

With the development of society, higher demands are put on the precision and the high efficiency of material processing. Particularly, with the rapid development of the IT industry, high-tech electronic products such as liquid crystal displays, full-screen mobile phones, and the like are produced, and a large amount of glass needs to be accurately cut in the manufacturing process of the electronic products. In the prior art, a laser cutting mechanism for glass processing can only be generally suitable for cutting glass materials with specific thicknesses, and has poor adaptability, namely, one device can only adapt to the same focal depth and cannot adapt to a plurality of focal depths; and the existing laser cutting device has long overall structure size and complex structure, and generally comprises a plurality of lenses and objective lenses, so that the production cost is high and the price is high. In view of this, the present application aims to provide a laser cutting device adapted to multiple focal depths, which has the advantages of good processing effect, compact structure and low cost.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the above-mentioned not enough of prior art and providing a laser cutting device, this cutting device has the advantage that processing effect is good, compact structure and with low costs.

The technical scheme of the utility model is that: the utility model provides a laser cutting device, includes casing, quarter wave plate and lens, and quarter wave plate and lens are all installed in the casing, and the lens is including the diffraction cone lens, first lens and the second lens that arrange in proper order, and wherein diffraction cone lens is closer to quarter wave plate, and first lens and second lens constitute a two telecentric systems.

Furthermore, the quarter-wave plate is composed of substrate glass, protective glass and a liquid crystal molecular film layer, wherein the substrate glass is positioned in the middle, and the substrate glass, the protective glass and the liquid crystal molecular film layer are adhered together through optical glue.

Furthermore, the thickness of the substrate glass and the protective glass in the quarter-wave plate is 1.6mm, and the thickness of the liquid crystal molecular film layer is 3 um.

Furthermore, the diffraction cone lens is composed of substrate glass, protective glass and a liquid crystal molecular film layer, wherein the substrate glass is located in the middle, and the substrate glass, the protective glass and the liquid crystal molecular film layer are adhered together through optical glue.

Furthermore, the thickness of the substrate glass and the protective glass in the diffraction cone lens is 1.6mm, and the thickness of the liquid crystal molecular film layer is 5 um.

Further, the distance between the quarter-wave plate and the diffraction cone lens is adjusted according to actual conditions.

Furthermore, the distances from the diffraction cone lens and the second lens to the first lens are fixed values.

Furthermore, the shell is in a circular tube shape, the shell is provided with external threads, and the cutting device with the external thread structure can be conveniently installed.

Further, the distance between the diffraction cone lens and the first and second lenses can be kept fixed by a gasket structure.

Further, the effective distance of the first lens is 150mm and the size is 25.4mm, and the effective focal length of the second lens is 20mm and the size is 25.4 mm.

Furthermore, the diffraction cone lens adopts a micro-lens array structure to realize the function, so that the diffraction cone lens is flat and is easy to replace.

The utility model discloses a theory of operation: the laser is adjusted into left-handed (right-handed) circularly polarized light through the quarter-wave plate, annular light beams which are converged (diverged) are generated after passing through the diffraction cone lens, and the annular light beams are overlapped at a certain distance to generate quasi-Bessel light beams. And then, the Bezier light beam generated by the diffraction cone lens is transferred through a double telecentric system, and the quasi-Bezier light beam is converted into the required focal depth length and the required light spot size.

In the utility model, the arrangement mode of the liquid crystal in the liquid crystal molecular film layer in the diffraction cone lens is in a circular stripe shape, as shown in figure 2,

the phase of the diffraction cone lens is calculated as follows:

(1)

wherein p is a value twice the period of the circular stripe, and r is the element size;

the fast axis azimuth angle of the liquid crystal molecules is calculated as follows:

(2)

for different periods of the axicon, the diffraction angle is calculated as follows:

(3)

wherein, lambda is the design wavelength, theta is the diffraction angle;

the Bessel zone length calculation formula produced by the axicon is as follows:

(4)

wherein Zmax is the length of the quasi-bessel beam;

the calculation formula of the Bessel light spot size is as follows:

(5)

wherein k is a laser wavevector;

the first lens and the second lens form a double telecentric system, the first lens and the second lens meet the confocal condition, a beam reducer is formed, and the beam reducing magnification is 1/7X. The double telecentric system is used for converting the Bessel light beam by aligning the Bessel light beam, and the focal depth conversion formula is as follows

(6)

Wherein beta is the multiplying power;

the bessel spot size conversion formula is as follows:

(7)。

compared with the prior art the beneficial effects of the utility model: the cutting device of the utility model adopts the diffraction axicon lens, which can make the central intensity change of the Bessel area more flat, which is beneficial to processing; the cutting device of the utility model adopts a non-4F structure, and can be adapted to different diffraction cone lenses to obtain different focal depth lengths; the utility model discloses a cutting device adopts all to be single lens, does not use objective, the cost is reduced and the complexity.

Drawings

Fig. 1 is a schematic cross-sectional view of embodiment 1 of the present invention;

fig. 2 is a diagram showing an arrangement of liquid crystal molecular films observed under a polarizing microscope in a diffraction cone lens according to example 1 of the present invention;

in the figure: 1-quarter wave plate, 2-diffraction cone lens, 3-first lens, 4-second lens and 5-shell.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments, wherein methods and functional components not specifically described are known in the art.

Example 1

As shown in fig. 1, the present embodiment is a laser cutting apparatus, which includes a housing 5, a quarter-wave plate 1 and a lens, wherein the quarter-wave plate 1 and the lens are both installed in the housing, and the lens includes a diffractive axicon lens 2, a first lens 3 and a second lens 4 which are arranged in sequence, wherein the diffractive axicon lens 2 is closer to the quarter-wave plate 1, an effective distance of the first lens 3 is 150mm, a size of the first lens is 25.4mm, an effective focal length of the second lens 4 is 20mm, a size of the second lens is 25.4mm, the first lens 3 and the second lens 4 form a double telecentric system, and both satisfy a confocal condition to form a beam reducer.

In this embodiment, the quarter-wave plate 1 is composed of substrate glass, protective glass and a liquid crystal molecular film layer, wherein the substrate glass is located in the middle, the substrate glass, the protective glass and the liquid crystal molecular film layer are adhered together through optical glue, the thickness of the substrate glass and the protective glass in the quarter-wave plate 1 is 1.6mm, and the thickness of the liquid crystal molecular film layer is 3 um.

In this embodiment, the diffraction cone lens 2 is composed of a substrate glass, a protective glass and a liquid crystal molecular film layer, wherein the substrate glass is located in the middle, the substrate glass, the protective glass and the liquid crystal molecular film layer are adhered together through optical glue, the thickness of the substrate glass and the thickness of the protective glass in the diffraction cone lens 2 are 1.6mm, and the thickness of the liquid crystal molecular film layer is 5 um.

In this embodiment, the distance between the quarter-wave plate 1 and the diffractive axicon 2 can be adjusted according to actual situations. The distances between the diffraction cone lens 2 and the second lens 4 to the first lens 3 are kept constant. Distances are kept among the diffraction cone lens 2, the first lens 3 and the second lens 4 through a gasket structure.

In this embodiment, casing 5 is the pipe form, is equipped with the external screw thread on casing 5, can be convenient install through external screw thread structure laser cutting device and carry out work on the corresponding equipment.

The working process of the utility model is as follows:

firstly, the polarization state of the collimated parallel light beams is changed after passing through the quarter-wave plate, and the collimated parallel light beams are converted into circularly polarized light from original linearly polarized light. Since the polarization state may affect the convergence and divergence of the diffraction conic lens, in this embodiment, the polarization state may be adjusted to be left-handed circularly polarized light, so that the light passing through the diffraction conic lens is converged and then diverged.

And secondly, the left-handed circularly polarized light passes through a diffraction cone lens to obtain a hollow annular light beam which is converged and then diverged. Wherein a quasi-bessel beam can be formed under a certain length, and the quasi-bessel beam annular beam has a certain divergence angle, namely a diffraction angle. In actual laser cutting, the required cutting length (1-10 mm) is far shorter than the focal depth length (hundreds of millimeters) of a single diffraction cone lens, and the required light spot size (1-5 um) is far larger than the light spot size (tens of micrometers) generated by the single diffraction cone lens. Therefore, the quasi-bessel beam generated by the diffraction cone lens needs to be converted.

And thirdly, a double telecentric system consisting of the first lens and the second lens converts the quasi-Bessel light beam generated by the diffraction cone lens.

And fourthly, under the condition that the multiplying power of the double telecentric system is determined, the focal depths with different lengths can be obtained only by changing the diffraction angle of the diffraction cone lens, and the cutting tool can be used for cutting transparent materials (such as glass) with different thicknesses.

Use the utility model discloses a through experimental calculation, obtain following data:

when the diffraction angle of the diffraction cone lens is 2 degrees, the final focal depth length is 1mm, and the light spot size is 1.1 um.

When the diffraction angle of the diffraction cone lens is 0.73 degrees, the final focal depth length is 4mm, and the spot size is 4.03 um.

When the diffraction angle of the diffraction cone lens is 0.3 degrees, the final focal depth length is 10mm, and the light spot size is 10.25 um.

The diffraction angle of the diffraction cone lens can be designed according to the required depth of focus thickness. The formula is a little different from the actual design because it uses an ideal thin lens. The focal depth length (air) of 1-10 mm covers the cutting of most transparent materials basically, and most cutting requirements are met. The focal depth length is the length in the air. The focal depth length calculation formula corresponding to the transparent glass material is as follows:

wherein: n is the refractive index of the transparent material.

The above is only a partial embodiment of the present invention, and is not intended to limit the present invention, and to those skilled in the art, the present invention can have the combination and modification of the above various technical features, and those skilled in the art can replace the improvement, modification, equivalent replacement, or use the structure or method of the present invention in other fields to achieve the same effect without departing from the spirit and scope of the present invention, and all belong to the protection scope of the present invention.

Claims

1. The utility model provides a laser cutting device, includes casing, quarter wave plate and lens, and quarter wave plate and lens are all installed in the casing, its characterized in that: the lens comprises a diffraction cone lens, a first lens and a second lens which are sequentially arranged, wherein the diffraction cone lens is closer to the quarter-wave plate, and the first lens and the second lens form a double telecentric system.

2. A laser cutting apparatus according to claim 1, wherein: the quarter-wave plate is composed of substrate glass, protective glass and a liquid crystal molecular film layer, wherein the substrate glass is positioned in the middle.

3. A laser cutting apparatus according to claim 2, wherein: the thickness of substrate glass and protective glass in the quarter-wave plate is 1.6mm, and the thickness of liquid crystal molecule rete is 3 um.

4. A laser cutting apparatus according to claim 1, wherein: the diffraction cone lens is composed of substrate glass, protective glass and a liquid crystal molecular film layer, wherein the substrate glass is located in the middle.

5. The laser cutting device according to claim 4, wherein: the thickness of substrate glass and protective glass in the diffraction cone lens is 1.6mm, and the thickness of the liquid crystal molecular film layer is 5 um.

6. A laser cutting apparatus according to claim 1, wherein: the distance between the quarter-wave plate and the diffraction cone lens is adjusted according to actual conditions.

7. A laser cutting apparatus according to claim 1, wherein: the distances from the diffraction cone lens and the second lens to the first lens are fixed values.

8. A laser cutting apparatus according to claim 1, wherein: the shell is in a circular tube shape.

9. A laser cutting apparatus according to claim 1, wherein: the effective distance of the first lens is 150mm, and the size of the first lens is 25.4 mm.

10. A laser cutting apparatus according to claim 1, wherein: the second lens has an effective focal length of 20mm and a dimension of 25.4 mm.