KR20180083548A - A Laser Marking Apparatus Having a Structure of Focusing Real Time Based on a Measurement of Flatness - Google Patents

Abstract

The present invention relates to a laser marking apparatus having a real-time focusing structure by measurement of flatness, and more specifically, to a laser marking apparatus having a real-time focusing structure by measurement of flatness, which enables focusing to be adjusted in real time by measuring in real time a processing portion to be marked before performing a marking process and considering a predetermined focal distance. The laser marking apparatus of the present invention includes: a laser processing unit (16) which induces a laser generated from a laser generator (LG) to the surface of a workpiece (W); a focusing unit (13) which adjusts a focal point of the laser induced by the laser processing unit (16); and a short distance measuring unit (14) which measures a distance between a predetermined position and a marking portion of the workpiece, wherein the focusing unit (13) is operated based on distance information measured in the short distance measuring unit (14). According to the present invention, focus is able to be adjusted quickly and accurately.

Description

[0001] The present invention relates to a laser marking apparatus having a real-time focus adjustment structure by flatness measurement,

The present invention relates to a laser marking apparatus having a real-time focus adjustment structure by flatness measurement. More specifically, the present invention relates to a laser marking apparatus having a real- And more particularly, to a laser marking apparatus having a real-time focus adjustment structure by flatness measurement.

A laser marking device is a device that engraves characters, symbols, patterns or pictures on a surface of a material such as wood, plastic, metal, coated metal, stone, or glass with a laser beam. Generally, the laser marking apparatus can include a control device for controlling such things as a laser for generating a beam for the imprint, a direction, intensity, moving speed and distribution of the laser beam. In such a laser marking apparatus, a working material is fixed on an X-Y table, and a laser optical apparatus moves in an X-Y direction to imprint on a working material. On the other hand, the laser marking apparatus moves in the Y direction and can be imprinted while the laser moves in the X direction.

As a prior art related to laser marking, Patent Registration No. 10-0520899 'Marking correction method of laser marking system' is available. The prior art is a marking correction method for a laser marking system having a laser marker for performing marking while observing chips mounted in each cell of a tray with at least one vision camera and a post-vision camera for detecting a marked error, Assigning observation target chips to each of the vision cameras, matching the coordinates of the vision cameras and the laser markers, marking a predetermined first symbol at a position corresponding to each chip or each chip, Observing the selected first symbol and teaching one point of the symbol as a reference point; observing a first symbol and a reference point of the chip with the vision camera and marking a second symbol on the basis of the reference point on each chip; Observing a second symbol on the chip and teaching a comparison point of the symbol; And detecting the position of the comparison point and detecting a marking error in each cell.

Another prior art related to laser marking is Patent Registration No. 10-0771496 " Correction Apparatus and Method of Laser Marking System ". In the prior art, if a gap occurs in a height of a chip in a tray when the tray moves, if the size of the gap is within a certain range, the mark is corrected by correcting the gap, A laser beam oscillator for projecting a laser beam on a side of chips mounted on the tray to measure the height of the chips in the tray; And a vision camera for picking up the X and Y positions of the chips and detecting the laser beam projected from the laser beam oscillator to the sides of the chips.

The predetermined focal distance may vary for various reasons in the process of forming the marker in the workpiece, and the change of the focal length may be caused by various causes. And the change in focal length can be measured, for example, by a distance measurement detection unit such as an ultrasonic detection unit or a laser detection unit. However, the measurement method by the distance measurement detection unit has a disadvantage that it is difficult to assure that the measurement is performed on the machining area. In addition, it is advantageous that the focus adjustment to the machined part according to the change of the focus is performed accurately in a short time. However, the prior art does not disclose such a method.

The present invention has been made to solve the problems of the prior art and has the following purpose.

Prior Art 1: Patent Registration No. 10-0520899 (Io Technics Co., Ltd., October 28, 2005) Marking Correction Method of Laser Marking System Prior Art 2: Patent Registration No. 10-0771496 (Vis, Ltd., October 30, 2007) Correction Apparatus and Method of Laser Marking System

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser marking apparatus of a real time focus adjustment structure by measuring the flatness of a workpiece in real time so as to prevent a machining error from being generated.

According to a preferred embodiment of the present invention, a laser marking apparatus of a real-time focus adjustment structure by flatness measurement comprises a laser machining unit for guiding a laser generated from a laser generator to a surface of a workpiece; A focus adjustment unit for adjusting a focus of the laser which is guided to the laser processing unit; And a near field measurement unit for measuring a distance between the marking site of the workpiece and the predetermined position, wherein the focus adjustment unit is operated based on the distance information measured in the near field measurement unit.

According to another preferred embodiment of the present invention, the focusing unit comprises two lenses capable of adjusting the relative distance.

According to another preferred embodiment of the present invention, one of the two lenses is fixed at a predetermined position, and the other lens is arranged to be movable along a linear screw.

According to another preferred embodiment of the present invention, the distance to at least two points of the portion adjacent to the marked portion is measured by the near field measurement unit, and based thereon, the gradient with respect to the subsequent marking position is predetermined.

The laser marking apparatus according to the present invention measures the flatness or tilt of the workpiece in real time and adjusts the focus accordingly to prevent marking errors on the workpiece. Further, in the laser marking apparatus according to the present invention, the focus adjustment is performed by the movement of the lens, so that the focus adjustment can be performed quickly and accurately. Further, the laser marking apparatus according to the present invention can easily correct an error caused by various causes by determining an error of a focal distance by measuring an inclination.

1A and 1B show an embodiment of a laser marking apparatus according to the present invention.
2 shows an embodiment of a focusing unit applied to a laser marking apparatus according to the present invention.
FIG. 3 shows an example of a process of adjusting the focus by the laser marking apparatus according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, so that they will not be described repeatedly unless necessary for an understanding of the invention, and the known components will be briefly described or omitted. However, It should not be understood as being excluded from the embodiment of Fig.

1A and 1B show an embodiment of a laser marking apparatus according to the present invention.

1A and 1B, a laser marking apparatus includes a laser processing unit 16 for guiding a laser generated from a laser generator LG to a surface of a workpiece W; A focus adjustment unit 13 for adjusting the focus of the laser which is guided to the laser processing unit 16; And a near field measurement unit (14) for measuring a distance between the marking site of the workpiece and the predetermined position, wherein the focus adjustment unit (13) is operated based on the distance information measured in the near field measurement unit .

The laser generator (LG) for generating the laser beam can be any laser beam generator known in the art and can be any type of laser generator such as, for example, a carbon dioxide laser, a fiber laser or a Q-switched YAG laser But not limited to, any laser known in the art. The operation of the laser generator LG can be controlled by the control unit 11, for example, the data on the marking position can be stored in advance and the generation time of the laser accordingly can be controlled. The laser generator (LG) herein may be any shape capable of marking a label, bar code, letter, pattern or similar mark on the surface of a metal, plastic, wood glass or similar material by a laser. In this specification, the marker represents any mark that is marked on the surface of the work W by the laser processing apparatus.

The markers made on the workpiece W can be predetermined and focus data on the focal distance with respect to the different positions of the markers can be generated by the processing region focus determination unit 12. [ The focal distance can be, for example, the optical distance between the laser processing unit 16 and the marker. The laser processing unit 16 includes an F-theta lens 161 whose focal length can be the distance between the F-theta lens 161 and a predetermined point of the marker, - theta lens 161. The focal length of the lens can be determined by the following equation. The focus data may also include data on the planar coordinates of the markers in the workpiece W. The data generated in the processing region focus determination unit 12 may be transmitted to the control unit 11. [

The workpiece W can be transported by, for example, a transport unit CV such as a conveyor, and the laser machining unit 16 can be moved according to the structure of the laser marking apparatus. The moving structure of the workpiece W or the laser machining unit 16 can be adjusted by the control unit 11 by the control unit 11. [ The laser generator LG can be connected to the separator 19 and the reflection of the laser generated in the laser generator LG by the separation unit 19 can be prevented. The laser is focused by an apparatus such as the expander 18 and is transmitted to the workpiece W through the F-theta lens 161 by path forming units M1 and M2 such as a reflecting mirror to generate a marker can do.

According to the present invention, the distance between a specific site and a predetermined site can be measured by the near field measurement unit 14 before the specific site forming the marker is marked. The near field measurement unit 14 may be, for example, but not limited to, a laser distance measurement unit, an ultrasonic unit, or an optical unit. The near field measurement unit 14 can measure the focal distance to a specific site before a marker is formed by a laser at a specific site of the marker. The focal distance for at least two points can also be measured by the near field measurement unit 14, and the focal distance for at least two points can be measured in real time during the marking process. For example, the near-field measurement unit 14 may be installed on the side surface of the F-theta lens 161, and the focal distance for a specific region where the marker is to be formed may be measured before the workpiece W is moved to the marking position . It is possible to arrange a position determination detection unit 141 for confirming the relative positions of the near-field measurement unit 14 and the F-theta lens 161 as a reference of the focal distance. The position check detection unit 141 can confirm whether or not the near distance measurement unit 14 is in the predetermined reference position. The real focal length measured in real time by the near distance measurement unit 14 can be transmitted to the tilt determination unit 15. [

The actual focal distance measured in real time for at least two points by the tilt determining unit 15 and the focal distance of the focus data generated by the processing region determining unit 12 can be compared. For example, at least two actual focal lengths measured by the near-field measurement unit 14 at adjacent times may be transmitted to the tilt determination unit 15 and stored. The near distance measurement unit 14 can calculate the actual focal distance before the stored actual focal distance and the actual focal distance before the marking is performed by calculating the difference value of the focal distance for the relevant part stored in the focus data transmitted by the processing part focus determination unit 12 have. And determine the flatness or tilt of the marker portion to be machined based on the difference value. And the inclination or flatness of the marker portion determined in this way can be transmitted to the control unit 11. [ Then, the control unit 11 can operate the focus adjusting unit 13 based on the inclination or flatness with respect to the marker portion. The error of the focal length can be corrected based on the difference of the focal distance of the focus data generated by the focus adjustment unit 13 according to the inclination.

The focus adjustment unit 13 may be operated based on the distance information measured in the near distance measurement unit 14 and the focus adjustment unit 13 may include two lenses capable of adjusting the relative distance. The focus adjusting unit 13 may have a function of correcting an error of the focal length due to the variation of the flatness or the inclination in the focal distance of the generated focus data, thereby preventing the error of the marker generated by the laser marking apparatus . The focus adjustment unit 13 may be installed between the expander 18 and the path forming units M1 and M2 or may be installed in front of the F-theta lens 161, but is not limited thereto.

An embodiment of the focus adjusting unit 13 having such a function will be described below.

2 shows an embodiment of a focusing unit applied to a laser marking apparatus according to the present invention.

Referring to FIG. 2, the focus adjusting unit 13 may include two lenses 21 and 22 whose relative distances can be adjusted. The lens 22 of one of the two lenses 21 and 22 is fixed at a predetermined position and the other lens 21 can be arranged to be movable along the linear screw 24. [

The focus adjustment unit 13 includes a housing H having two wall faces P1 and P2 facing each other; A linear screw 24 such as a ball screw supported by two different wall surfaces Pl, P2; An induction guide 23 extending along the extending direction of the linear screw 24; A positioning drum 241 coupled to the linear screw 24; A lens-moving member 232 extending from the position adjusting drum 241 in the direction of the guide 23; An induction member 231 coupled to the lens-moving member 232 to move the lens-moving member 232 along the induction guide 23; A lens moving member 232 and one or two lenses 21 and 22 arranged on two wall surfaces P2.

The two wall surfaces P1 and P2 can be arranged to face each other and an inlet LO into which the laser LR flows can be formed on one wall surface P1. The laser LR introduced through the entrance LO is focused through the lens moving member 232 and the first and second lenses 21 and 22 disposed on the two wall surfaces P2 to adjust the focal point of the F- 161 < / RTI > The first and second lenses 21 and 22 may be concave and convex lenses 22, respectively, but not limited thereto, and various types of focusable lenses may be arranged in various structures. Focus adjustment can be achieved by adjusting the distance between the lenses 21, 2, the two lenses 22 corresponding to the convex lenses are fixed to the two wall surfaces P2, and one lens 21 corresponding to the concave lens is linearly arranged with respect to the two lenses 22 The focal length can be adjusted by being moved. The lens moving member 232 provided with the one lens 21 can be moved along the linear screw 24 and the guide 23 according to the rotation of the linear screw 24. [ According to one embodiment of the present invention, the one lens 21 can be moved up and down along the guide guide 23 and is provided with a position detection unit (not shown) for measuring the height difference between the first and second lenses 21 and 22 233 may be disposed on the lens-moving member 232.

The linear screw 24 includes a linear member 242 supported by a rotation support unit 245 such as a bearing provided on the wall surfaces P1 and P2; A positioning drum 241 coupled to the linear member 242; And a drum pitch detecting unit 243 disposed on both sides of the position adjusting drum 241. [ The linear member 242 can be rotated by a drive unit 25 such as a motor and for this purpose the rotary means 262, such as a pulley coupled to the drive shaft 261 and the linear member 242, And may be connected by a power transmission means 263 such as a belt. The linear member 242 can be rotated by the rotation of the drive unit 25, and accordingly the position adjusting drum 241 can be moved. The drive unit 25 is rotated in different directions so that the position adjusting drum 241 can be moved in the forward and backward directions. The position of the position adjusting drum 241 can be detected by the drum pitch detecting unit 243 and transmitted to the control unit. The control unit can calculate the moving distance of the one lens 21 according to the focal distance to be corrected. The driving unit 25 can be operated based on the current position of the position adjusting drum 241 detected by the drum pitch detecting unit 243 to adjust the position of the one lens 21 to adjust the focal distance.

Modification of the focal length by the two lenses 21, 22 can be done in various ways, and the present invention is not limited to the embodiments shown.

FIG. 3 shows an example of a process of adjusting the focus by the laser marking apparatus according to the present invention.

Referring to FIG. 3, the process of modifying the focus in the laser marking apparatus includes a step P31 of preparing a machining program for machining a workpiece; A step (P32) of determining a focus map of the material position for the marker formed by the parting program; (P33) a marker is formed by laser machining based on the focal point; A step P34 of measuring the slope in the process of forming the marker; A step (P35) in which it is confirmed whether an inclined deviation has occurred in the measured inclination; A step (P36) of setting a rotation angle of the drive unit to adjust a relative distance of the lenses arranged to face each other; A step (P37) of determining a moving time of the lens based on the set rotation angle; And a step P38 in which the adjustment lens is moved to correct the focal length.

Based on the marker to be formed on the workpiece, the movement method of the workpiece or the laser device can be determined, the generation time of the laser can be determined, and such can be set by the machining program (P31). Once the part program is created, the focal lengths for different parts of the marker can be calculated to determine the focus map, and the focus map can include, for example, the focus data for which the focal length for each part of the marker is stored ( P32). Laser processing can be performed to form a marker based on the focus data (P33), and a distance measurement can be made to the adjacent positions of at least two specific portions before machining is performed on the specific portion of the marker. Then, based on the measured distance, the inclination to the specific portion can be measured, and the actual focal length can be calculated (P34). The actual focal distance and the focal distance of the focus data can be compared to determine whether the slope deviation has occurred or not, and whether or not the slope deviation requiring the correction of the focal distance has been generated (P35). If no warp deviation occurs (NO), laser processing for a specific region can be performed (P33). If an inclination deviation has occurred (YES), the rotation angle of the drive unit for adjusting the relative distance of the lens can be set (P36). The drive unit may be a device such as a motor capable of adjusting the rotation angle. As described above, by rotating the ball screw, one of the two lenses facing each other can be moved to adjust the relative distance of the lens. The focus adjustment must be performed immediately before a specific portion of the marker is marked. To this end, the operating point of the drive unit may be determined based on the coordinate of the workpiece prepared in the machining program and the moving time point thereof (P37). The operation of the drive unit at the time of operation allows movement of the adjustment lens, which is the movement of the two lenses, to correct the focal length (P38). And a specific portion of the marker may be processed based on the corrected focal length (P33).

The laser marking apparatus according to the present invention can be operated in various ways and the present invention is not limited to the embodiments shown.

The laser marking apparatus according to the present invention measures the flatness or tilt of the workpiece in real time and adjusts the focus accordingly to prevent marking errors on the workpiece. In addition, in the laser marking apparatus according to the present invention, the focus adjustment is performed by the movement of the lens so that the focus adjustment can be performed quickly and accurately. Further, the laser marking apparatus according to the present invention can easily correct an error caused by various causes by determining an error of a focal distance by measuring an inclination.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention . The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

11: control unit 12: machining site focus determination unit
13: Focus adjustment unit 14: Near measurement unit
15: inclination determination unit 16: laser processing unit
18: Expander 19: Separation unit
21, 22: 1, 2 Lens 23: Induction guide
24: Linear screw 25: Drive unit
141: Positioning detection unit 161: F-theta lens
231: Inducer member 232: Lens moving member
233: Position detection unit 241: Positioning drum
242: Linear member 243: Drum pitch detection unit
245: rotation support unit 261: drive shaft
262: rotating means 263: power transmitting means
CV: Transfer unit H: Housing
LG: Laser generator LO: Entrance
LR: laser M1, M2: path forming unit
P1, P2: 1, 2 Wall W: Machined material

Claims (4)

In the laser marking apparatus,
A laser processing unit 16 for guiding the laser generated from the laser generator LG to the surface of the workpiece W;
A focus adjustment unit 13 for adjusting the focus of the laser which is guided to the laser processing unit 16; And
And a near field measurement unit (14) for measuring the distance between the marking sites of the workpiece from the predetermined position, wherein the focus adjustment unit (13) is operated based on the distance information measured in the near field measurement unit Wherein the laser marking device is characterized by: The laser marking apparatus according to claim 1, wherein the focus adjusting unit (13) comprises two lenses (21, 22) capable of adjusting a relative distance. The laser according to claim 2, characterized in that one of the two lenses (21, 22) is fixed in a fixed position and the other lens (21) is arranged to be movable along a linear screw (24) Marking device. 2. A laser marking system according to claim 1, characterized in that a distance to at least two points of a portion adjacent to the marked portion is measured by the near-field measurement unit (14), and an inclination with respect to the subsequent marking position is predetermined based thereon Device.

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