CN110666344A

CN110666344A - Laser device and version roller engraver

Info

Publication number: CN110666344A
Application number: CN201910992994.2A
Authority: CN
Inventors: 孟凡祥; 冯志伟; 曾庆涛; 李福恩
Original assignee: HESHAN JINGGONG PLATE-MAKING Co Ltd
Current assignee: HESHAN JINGGONG PLATE-MAKING Co Ltd
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-01-10

Abstract

The invention discloses a laser device and a plate roller engraving machine, wherein the laser device comprises a laser, an absorber and an optical assembly, wherein the optical assembly comprises a collimating lens, a focusing lens and a beam expanding lens group; the laser beam is emitted by the collimating lens in a collimating way and sequentially passes through the absorber, the beam expanding lens group and the focusing lens to generate light spots. The laser engraving machine has the advantages that the laser engraving machine can block the laser beam from being emitted through the absorber when the laser does not need to be emitted, the laser beam is focused after being collimated and expanded, the laser focusing effect is better, the light spot formed by focusing is smaller, the smaller light spot is beneficial to engraving of ultra-precise patterns, the laser engraving precision is effectively improved, and the laser engraving machine is more stable and reliable and is suitable for high-precision plate roller engraving machines.

Description

Laser device and version roller engraver

Technical Field

The invention relates to the field of laser processing, in particular to a laser device and a plate roller engraving machine using the same.

Background

With the upgrading of consumption, the personalized demand is continuously emerging, the demands of high-end special paper, wood grain decoration, leather materials, garment materials, special material coating printing and the like are rapidly expanded, the market demands for special gravure technology are increasingly vigorous, and the demand for special ultra-precise printing roller is increased. The laser printing belongs to one of gravure technologies, is widely applied to the high-end laser packaging industry, and occupies an extremely important position in the field of special material printing due to the advantages of thin imprinting of a coating, fine pattern, high printing plate printing durability, stable quality of a printed product, high printing speed and the like.

The existing high-end special ultra-precise printing plate rollers basically depend on import, and the customization price of the imported plate rollers is high, the period is long, and the difference between the actual production and the market is larger and larger. The problem of low engraving precision of the existing domestic laser engraving equipment generally exists, and particularly for a laser printing plate roller, the engraving resolution of the existing laser engraving equipment is not enough to engrave a high-precision laser pattern, so that the market requirement cannot be met.

Disclosure of Invention

The invention aims to solve at least one technical problem in the prior art, and provides a laser device suitable for ultra-fine engraving, which can be suitable for engraving a high-precision laser printing plate roller and is practical and reliable.

The invention also provides a plate roller engraving machine applying the laser device.

A laser apparatus according to an embodiment of a first aspect of the present invention includes:

a laser for generating a laser beam;

the absorber is used for controlling and blocking the laser beam; and the number of the first and second groups,

the optical assembly comprises a collimating lens, a focusing lens and a beam expanding lens group;

the laser beam sequentially passes through the collimating lens, the absorber, the beam expander set and the focusing lens to generate light spots.

The laser device according to the embodiment of the invention has at least the following beneficial effects: laser device utilizes the laser instrument to produce laser beam, and with laser beam in proper order through the collimating mirror, the absorber, beam expanding mirror group and focusing mirror after produce the facula, block the effluvium of laser beam through the absorber when need not to emit the laser, laser beam focuses again after collimation and expansion, make laser focusing effect better, the facula that is formed by the focus is littleer, littleer facula is favorable to the sculpture of ultra-precise pattern, effectively improve the laser sculpture precision like this, and is more stable and reliable, and is applicable to high accuracy version roller engraver.

According to some embodiments of the invention, the beam expander set comprises a first beam expander and a second beam expander, and the laser beam passes through the first beam expander and the second beam expander in sequence.

According to some embodiments of the invention, the first beam expander is a 2-8 times electrically adjustable beam expander and the second beam expander is a 2 times or 2.5 times beam expander.

According to some embodiments of the invention, the absorber comprises an absorption light box and an optical path deflector controlling changing a direction of the laser beam and being incident to the absorption light box.

According to some embodiments of the invention, the collimating diameter of the collimating mirror is 2-3 mm.

According to some embodiments of the invention, the focusing lens comprises a rotating base and a plurality of aspheric focusing lenses circumferentially arranged on the rotating base.

According to some embodiments of the invention, the rotary base comprises aspheric focusing lenses with focal lengths of 30mm, 50mm, 100mm and 150 mm.

According to some embodiments of the invention, the laser is a picosecond pulse laser.

A plate roll engraver according to an embodiment of the second aspect of the invention, comprising a laser device for engraving a plate roll according to any one of the preceding claims 1 to 8.

According to some embodiments of the invention, the device further comprises a rotation driving device for driving the plate roller to rotate and a movement driving device for driving the laser device to move along the axial direction of the plate roller.

The plate roller engraving machine provided by the embodiment of the invention at least has the following beneficial effects: this version roller engraver adopts foretell laser device, the laser beam that laser device produced passes through the collimating mirror in proper order, the absorber, the beam expanding mirror group produces the facula behind focusing mirror, block the ejaculate of laser beam through the absorber when need not ejaculate the laser, laser beam focuses on again after collimation and expansion, make laser focusing effect better, the facula that is formed by the focus is littleer, littleer facula is favorable to the sculpture of ultra-precise pattern, effectively improve laser sculpture precision like this, it is more reliable and more stable, this version roller engraver can carve out the pattern of high accuracy on printing plate roller, the sculpture of specially adapted laser printing pattern, it is more efficient to make laser printing plate roller, and is more reliable.

Drawings

The invention is further described below with reference to the accompanying drawings and examples;

FIG. 1 is a schematic diagram of the working principle of a laser device according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a focusing lens according to an embodiment of the present invention;

fig. 3 is a schematic side view of a plate roller engraving machine according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a printing plate roller according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

In the description of the present invention, it should be understood that the positional descriptions, such as the directions of up, down, front, rear, etc., referred to herein are based on the directions or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular direction, and thus should not be construed as limiting the present invention.

In the description of the present invention, if there are first and second described only for the purpose of distinguishing technical features, it is not understood that relative importance is indicated or implied or that the number of indicated technical features or the precedence of the indicated technical features is implicitly indicated or implied.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Referring to fig. 1, a laser apparatus 100 according to an embodiment of the present invention is described, where the laser apparatus 100 includes a laser 110, an absorber 120, and an optical assembly, where the optical assembly includes a collimating lens 130, a focusing lens 150, and a beam expander set 140, the collimating lens 130 is located at an exit port of the laser 110, an entrance port of the absorber 120 corresponds to an exit port of the collimating lens 130, and the beam expander set 140 and the focusing lens 150 are arranged at an exit port of the absorber 120.

The collimating lens 130 is a transmissive collimating lens, the collimator is fixed on the exit port of the laser 110, the laser beam generated by the laser 110 is emitted after being collimated by the collimating lens 130, the collimation property of the laser beam can be ensured, and the collimating aperture emitted by the collimating lens 130 is equivalent to the aperture of the entrance port of the absorber 120, so that the collimated laser beam can enter the absorber 120. Of course, the collimating aperture of the collimating mirror 130 may be smaller than the entrance aperture of the absorber 120. Since switching of the laser beam cannot be controlled by means of the switching laser 110, an absorber 120 is added to the optical path, and the absorber 120 functions to controllably block the emission of the laser beam. In a normal working state, the laser beam directly passes through the absorber 120 without generating a blocking effect; when the laser beam does not need to be emitted, the absorber 120 blocks the emission of the laser beam, that is, the laser beam reaches the absorber 120 and is cut off, so that the laser device 100 cannot generate a light spot, and the absorber 120 works stably and reliably.

The beam expander set 140 and the focusing lens 150 are sequentially arranged along an optical path and located on one side of an exit port of the absorber 120, after the laser beam is expanded by the beam expander set 140, the divergence angle of the laser beam is reduced, and the laser beam is focused by the focusing lens 150, so that the laser beam can be focused to be smaller, and a fine light spot is formed. The number of the beam expanders and the beam expansion ratio in the beam expander set 140 are set according to actual requirements, the beam expanders can be matched with the focusing lens 150 to meet the requirement of generating light spots with small enough sizes, theoretical light spots can be 2-3 microns, and the laser engraving device is suitable for engraving fine laser patterns 320.

In an embodiment, the beam expander set 140 includes a first beam expander 141 and a second beam expander 142, and the laser beam emitted from the absorber 120 sequentially passes through the first beam expander 141 and the second beam expander 142 to perform two-stage beam expansion. The first beam expander 141 is an electrically adjustable beam expander, which is also called an electrically variable power beam expander, and has a beam expansion ratio of 2-8 times, and the first beam expander 141 expands the beam diameter and adjusts the divergence through electrical control and adopts integrated control. The second beam expander 142 adopts a beam expander with a beam expansion ratio of 2.5 times, take the example that the first beam expander 141 sets 4 times beam expansion, expand the beam diameter of the laser beam to 4 x 2.5 x 10 times after the beam expansion through the first beam expander 141 and the second beam expander 142, the divergence angle of the expanded laser beam is also reduced, the divergence angle is reduced to 1/10, and the laser beam is focused through the focusing lens 150, thus, a very small light spot is generated after focusing, and because the light spot is Gaussian distributed, the high edge energy of the intermediate energy is low, and the diameter of the formed light spot acting on the metal surface can be smaller than 2 micrometers due to matching of factors such as power, acting time and the like.

It is to be understood that the positional relationship between the first beam expander 141 and the second beam expander 142 is not limited to that described in the above embodiments, and the absorber 120 may be disposed between the first beam expander 141 and the second beam expander 142, and certainly not limited to two beam expanders. In addition, a diaphragm 160 may be disposed between the beam expander set 140 and the focusing lens 150, and the beam diameter of the laser beam may be further limited by the diaphragm 160, so as to generate a laser spot with a stable size, and the diaphragm 160 may be a conventional optical diaphragm, which is not described herein again.

In an embodiment, the absorber 120 includes an absorption light box 122 and an optical path deflector 121, the absorption light box 122 is a light trap for absorbing the laser beam, and the optical path deflector 121 can change the direction of the laser beam so that the laser beam is emitted into the absorption light box 122 to block the laser beam.

Referring to fig. 1, in detail, the optical path deflector 121 rotates the mirror 123 mechanically to change an incident angle of the laser beam, so as to achieve the purpose of deflecting the optical path, the laser beam is deflected and then enters the absorption light box 122, and the energy of the laser beam is absorbed by the absorption light box 122, so that the laser beam cannot exit the absorber 120. Among them, the mirror 123 is driven by a high-speed motor, and the response is rapid. In normal operation, the laser beam is not deflected by the optical path deflector 121, i.e., the laser beam is directly emitted without passing through the absorption box 122. When the laser engraving device is applied to laser engraving, the laser 110 continuously emits laser beams, and the light path deflector 121 controls light path deflection to block the emission of the laser beams at positions where engraving is not needed, so that accurate engraving patterns are realized. Other structures and operations of the absorber 120 according to the embodiment are known to those of ordinary skill in the art and will not be described herein. The direction indicated by the arrow in fig. 1 is the light path.

In an embodiment, the collimating diameter of the collimating lens 130 is 2.5mm, and taking a first beam expander 141 of 4 times and a second beam expander 142 of 2.5 times as an example for explanation, the diameter of the beam emitted after the laser beam is collimated is 2.5mm, and after the beam is expanded by the first beam expander 141 and the second beam expander 142 in sequence, the diameter of the laser beam reaches 25mm, so that the diameter of the laser beam is increased, the divergence angle is reduced, and then the laser beam is focused by the focusing lens 150. The advantage of expanding the beam while obtaining less divergence is that the laser beam can be focused better with a smaller focused spot.

Referring to fig. 2, in the embodiment, the focusing lens 150 is a rotary focusing lens, the focusing lens 150 includes a rotary base 151, four aspheric focusing lenses 152 are disposed on the rotary base 151, the diameter of each aspheric focusing lens 152 is 40mm, the focal length is 30mm, 50mm, 100mm and 150mm, the aspheric focusing lenses 152 are uniformly arranged on the rotary base along the circumferential direction, and thus, the laser beam penetrates through the aspheric focusing lenses 152 with different focal lengths through the rotation of the rotary base, so that the focusing adjustment is convenient, the use is more flexible and convenient, and the efficiency is higher.

The laser 110 adopted in the embodiment is a 50W picosecond pulse laser, the laser pulse width of the laser 110 is less than 10ps, the laser is suitable for a micro-fine processing technology, a laser beam is emitted by the 50W picosecond pulse laser 110, and the laser beam is collimated, expanded and focused to obtain an ultrafine spot. Because the ultra-narrow pulse width acts on the surface of the material for a short time, the high peak energy and the ultra-fine light spots are combined, and the high-precision fine carving can be realized.

Referring to fig. 3, a plate roller engraving machine 200 according to another embodiment of the present invention includes the laser device 100 of the above embodiment, engraves a plate roller 300 by using an ultra-fine spot generated by the laser device 100, has high engraving accuracy, is particularly suitable for a laser printing plate roller 300, and can engrave a laser pattern 320 on the plate roller 300 and print a laser pattern on a material such as wrapping paper by using the plate roller 300 with the laser pattern 320.

Specifically, the plate roller engraving machine 200 includes a laser device 100, a rotation driving device 210 and a movement driving device 220, wherein the rotation driving device 210 is configured to drive the plate roller 300 to be engraved to rotate, and the movement driving device 220 is configured to drive the laser device 100 to move along the axial direction of the plate roller 300. The rotation driving device 210 includes a front end rotation head 211, a tail end rotation head 212, and a rotation driving motor, where the front end rotation head 211 and the tail end rotation head 212 are symmetrically disposed on the machine tool 230, and are used to clamp two ends of the roller 300 to be engraved in a matching manner. The movement driving device 220 includes a moving stage 221 and a movement driving motor, the moving stage 221 is disposed on one side of the position of the plate roll 300 to be engraved and is capable of moving back and forth between the leading-end rotating head 211 and the trailing-end rotating head 212, and the laser device 100 is mounted on the moving stage 221.

In order to make the moving position of the moving stage 221 more accurate and stable, a guide rail matched with the moving stage 221 is provided on the machine tool 230. The moving driving motor drives the moving platform 221 to move along the guide rail, so that the moving platform 221 drives the laser device 100 to move along the axial direction of the plate roller 300, and the laser beam emitted by the laser device 100 is used for engraving the plate roller 300 while moving, which is beneficial to improving the engraving accuracy.

During operation, the plate roller 300 to be engraved is fixed and clamped between the front rotating head 211 and the tail rotating head 212, and the front rotating head 211 and the tail rotating head 212 are driven to rotate by the rotating driving motor, so that the plate roller 300 to be engraved is driven to rotate. At this time, the laser device 100 is started, the laser device 100 generates a light spot, and the light spot is projected onto the surface of the plate roller 300 to perform engraving. Laser beams generated by the laser device 100 are expanded and focused to form light spots, the light spots are in Gaussian distribution, the intermediate energy is high, the edge energy is low, the light spots formed on the surface of the plate roller 300 can reach the micron level, and therefore ultra-fine patterns can be carved. And the microscopic wrinkle deformation is generated on the surface of the spot ablation material through the control of the engraving parameters, such as power, action time and other factors, thereby showing gorgeous color effect, forming the laser pattern 320, and being used for high-precision laser printing.

Referring to fig. 4, it can be understood that the plate roller engraving machine 200 can engrave a fine laser pattern 320 on the surface of the plate roller 300, and the plate roller 300 can be applied to high-precision printing of high-end specialty paper, wood grain decoration, leather materials, garment materials, specialty material coatings, and the like, and has a better laser effect.

In order to match the high-precision engraving requirement of the plate roller engraving machine 200, the adopted plate roller 300 also needs to be specially processed, the plate roller 300 is made of 316 stainless steel, the surface of the plate roller 300 is a mirror surface 310 formed through multiple polishing procedures, and fine light spots generated by the laser device 100 act on the mirror surface 310 to deform the mirror surface 310, so that the gorgeous color effect is presented, and a laser pattern 320 is formed.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. A laser device, comprising:

a laser for generating a laser beam;

2. The laser device of claim 1, wherein: the beam expander group comprises a first beam expander and a second beam expander, and the laser beams sequentially pass through the first beam expander and the second beam expander.

3. The laser device of claim 2, wherein: the first beam expander is a 2-8 times electric adjustable beam expander, and the second beam expander is a 2 times or 2.5 times beam expander.

4. The laser device of claim 1, wherein: the absorber includes an absorption light box and an optical path deflector that controls changing a direction of the laser beam and is incident to the absorption light box.

5. The laser device of claim 1, wherein: the collimation diameter of the collimation lens is 2-3 mm.

6. The laser device of claim 1, wherein: the focusing lens comprises a rotating seat and a plurality of aspheric focusing lenses arranged on the rotating seat along the circumferential direction.

7. The laser device of claim 6, wherein: the rotary seat comprises aspheric focusing lenses with focal lengths of 30mm, 50mm, 100mm and 150 mm.

8. The laser device according to any one of claims 1 to 7, wherein: the laser is a picosecond pulse laser.

9. A version roller engraver which characterized in that: laser device for engraved printing roller comprising any of the preceding claims from 1 to 8.

10. The plate roll engraver according to claim 9, characterized in that: the device also comprises a rotation driving device for driving the plate roller to rotate and a movement driving device for driving the laser device to move along the axial direction of the plate roller.