JP4304037B2 - Laser marking device - Google Patents

Description

  The present invention relates to a laser marking apparatus, and more particularly to an apparatus for improving printing quality.

Conventionally, a laser that prints characters, symbols, figures, etc. on glass using an infrared laser with a wavelength that does not pass through glass (specifically, a CO2 laser of carbon dioxide gas with a wavelength of 10.6 μm in consideration of economics). There is a marking device.
By the way, as shown in FIG. 11, when laser light 910 is directly applied to glass at normal temperature (hereinafter referred to as “glass product 900”), a minute crack 901 is generated around the printing portion due to thermal shock (heat shock). In some cases, the printing quality is deteriorated, and as a result, the quality of the glass product itself is deteriorated. In order to avoid such a problem, a method as shown in FIG. This is because, as shown in FIG. 12A, in a glass product manufacturing process, a glass 930 that is still softened at a high temperature is irradiated with a laser beam 910 in a molding stage from a liquid molten glass 920. This is a printing method.

However, in the conventional method described above, it is necessary to perform printing on a glass product within the glass manufacturing process, which can be performed only by the glass manufacturer. In order to solve such a problem, Japanese Patent Laid-Open No. 62-292655 discloses that a glass product 900 shipped from a glass manufacturer is reheated by a heating device as shown in FIG. A method of performing printing with a laser beam 910 on the softened glass 930 is disclosed.
JP 2000-67785 A

However, in this method, since the entire glass product 900 is heated regardless of which part is printed, it takes time. In addition, since a configuration for heating is necessary separately from the configuration originally necessary for the laser marking apparatus, there is a problem that this leads to an increase in size and cost of the entire apparatus.
In order to solve the above problem, the applicant of the present invention invented a method disclosed in Japanese Patent Laid-Open No. 2003-136259. According to this, even if marking is performed on a glass product, high print quality can be maintained without causing cracks. In addition to this, the applicant of the present application repeated trial and error in order to further speed up the printing process.

  The present invention has been made in view of the above circumstances, and its purpose is to avoid the increase in size and cost of the entire apparatus while enabling direct printing on an object to be marked (glass member, super-hardened material member). The present invention provides a laser marking apparatus capable of performing the above.

As a means for achieving the above object, the invention of claim 1 irradiates a laser beam from a laser beam emitting means onto a print area of an object to be printed through a galvano mirror device and a converging lens, and In a laser marking apparatus that scans the laser beam on the print area by operating a mirror device and prints marking information such as characters, symbols, and figures on the print area.
The laser beam emitting means has a first laser beam condensed at a first spot diameter on the print area, and a second spot diameter that is also an energy fluence that cannot be marked on the print area, And a second laser beam that is irradiated onto a region including the condensing position of the first laser beam, and the energy fluence in the first or second laser beam is At the start point of each line segment element in the marking information, the overlapping position of the spot of the first laser beam and the spot of the second laser beam is increased from an energy fluence that cannot be marked to an energy fluence that can be marked. Energy fluence change for changing the energy fluence of the first or second laser beam Characterized in place and a stage.

  According to a second aspect of the present invention, in the first aspect, the laser beam emitting means includes one laser light source, and the energy fluence changing means is configured to change the laser output of the laser light source. However, it has characteristics.

According to a third aspect of the present invention, in the first or second aspect, the energy fluence changing means divides an optical axis of the laser beam from the laser light source into two optical axes, so that the first and the first are changed. Splitting means for generating two laser beams;
Beam diameter changing means for changing one of the first and second laser beams;
The first and second laser beams are arranged on the same optical axis and are composed of combining means for guiding the first and second laser beams to the galvanometer mirror device.

  According to a fourth aspect of the present invention, in the first or second aspect, the energy fluence changing unit includes a beam expander and a composite lens having different focal lengths, and the beam expander and the composite By changing the distance to the lens or the beam diameter of the laser light emitted from the beam expander, the energy of one or both of the first and second laser lights having different focal lengths emitted from the compound lens It is characterized in that it is configured to change the fluence.

  According to a fifth aspect of the present invention, the energy fluence changing means according to any one of the third or fourth aspect of the invention is characterized in that the optical axis of the first laser light or the optical axis of the second laser light. It is characterized in that it is constituted by laser light attenuating means that is arranged on at least one optical axis and attenuates the laser light.

  The invention of claim 6 is characterized in that, in any of claims 1 to 5, the object to be marked is a super-hardened material member or a glass member.

In the present invention, first, the print position is heated by irradiating the condensing position (print position) of the object to be printed (the print position) and its periphery with an energy fluence that is not marked with the second laser light, and the first or first The marking process is performed by gradually increasing the energy fluence of the laser beam 2 and irradiating the laser beam having an energy fluence sufficient to enable marking on the print position irradiated with the first and second laser beams. . In this way, high print quality can be maintained without causing cracks in the object to be printed. Moreover, since the heating and the marking are performed simultaneously, the time for the marking process can be greatly shortened.
Specifically, the energy fluence changing means for changing the energy fluence includes a beam diameter changing means for changing the beam diameter of the first or second laser light, a laser light attenuating means for attenuating the laser light, and a laser light source A configuration in which the laser output is changed can be considered.
Of these, the beam diameter changing means can be constituted by a converging lens, a diverging lens, or the like that enlarges or reduces the beam diameter of the laser beam. The laser light attenuating means can be configured using a specific attenuation filter, a liquid crystal shutter, or the like.
In addition, super-hardened material members made of iron-based materials such as carbon steel, or glass members made of glass materials are particularly susceptible to cracking, but it is difficult to perform such marking by applying the above marking device. In this configuration, marking can be effectively performed.
“Energy fluence” indicates the amount of energy per unit area, and the unit is, for example, J / m ² or J / cm ² , and J / cm ² is often used.

<Embodiment 1>
An embodiment of a laser marking device according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram conceptually showing the structure of the laser marking apparatus of the first embodiment. The laser marking device 1 in this figure is mainly composed of a laser light source 210 configured as, for example, an infrared laser or the like that emits laser light having a wavelength of 4.8 μm or more (in the example of this embodiment, carbon dioxide gas (CO 2 having a wavelength of 10.6 μm). A galvanometer mirror 220 that changes the direction of the laser beam from the laser light source 210, and a converging lens that converges the laser beam from the galvanometer mirror 220 to form a laser spot on the object to be marked. (Fθ lens 800). Further, the laser light source 210 is driven and controlled, and the galvano mirror 220 is driven and controlled so that marking information such as characters, symbols, and figures is marked by scanning the laser spot and performing a predetermined marking operation. The control unit 130 corresponds to a marking control unit that performs such marking control.

The laser marking apparatus 1 mainly includes a controller unit 100 and a head unit 200, and each configuration will be described in detail below.
The controller unit 100 includes a console (such as a keyboard of a personal computer) as an input means 110 for inputting marking information such as characters, symbols, and figures to be marked on a workpiece 300 made of a crack-generating material such as glass. And a data generation unit 120 for obtaining a plurality of coordinate data based on the marking information input from the console (input unit 110).

  Further, the controller unit 100 is provided with a storage unit 140 that stores a plurality of coordinate data generated by the data generation unit 120, and the control unit 130 sequentially outputs the plurality of coordinate data stored in the storage unit 140. To recognize whether the multiple coordinate data is the coordinate data of the end point that is the start point and the end point, and to control the output of the multiple coordinate data, ON / OFF of the laser light source, etc. It is configured. Further, a line driver and a line receiver (hereinafter referred to as a line driver / receiver 50A) for transmitting and receiving signals such as coordinate data to and from the head unit 200 are provided.

  On the other hand, the head unit 200 is provided with a line driver and a line receiver (hereinafter referred to as a line driver / receiver 50B) for transmitting and receiving signals such as coordinate data to and from the controller unit 100. An optical system 700 including a beam expander 710 that is a beam diameter expanding means for expanding the beam diameter of the laser light from the laser light source 210, and the direction of the laser light emitted with the beam diameter expanded by the beam expander 710 The above-described galvanometer mirror 220 for changing the angle and the converging lens (fθ lens 800) for forming a laser spot on the workpiece 300 by irradiating the workpiece 300 with the laser light from the galvanometer mirror 220 are provided. In addition, a D / A conversion unit 230 that converts a plurality of coordinate data sent from the storage unit 140 of the controller unit 100 via the line driver / receiver 50B into corresponding voltages, and the D / A conversion unit And a servo circuit 240 for driving and controlling the galvano mirror 220 based on the voltage from 230, and further, a voltage corresponding to each coordinate data from the D / A conversion means 230 and a voltage corresponding to the driving amount of the galvano mirror 220 Based on the above, an approach state detecting means 250 for detecting the approach state of the irradiation position of the laser beam with respect to the coordinate data of the end point is provided.

  The galvanometer mirror 220 includes an X-axis galvanometer mirror 220X that changes the direction of the laser beam in one direction, and a Y-axis galvanometer mirror 220Y that changes the direction of the laser beam in a direction orthogonal to the X-axis direction. The laser beam is scanned in a two-dimensional direction by driving two galvanometer mirrors.

Next, the function of each component at the time of marking will be described.
When the marking process is performed, marking information such as characters, symbols, and figures to be marked is input by the console (input unit 110). In addition to the input means 110, the console also has an output device (not shown) having a display unit. Since the input marking information can be confirmed by the display unit, the marking information is input while viewing this display.

  When a trigger signal for starting the marking data generation is input from the console 110, the data generation means 120 receives the trigger signal, and the data forming unit 120 forms lines, characters, graphics, and symbols that are marking information with respect to the input marking information. Decompose into minute elements to obtain the coordinate data of the start and end points. The coordinate data also includes line type information indicating whether the line segment element is a straight line or a curve.

  After the coordinate data is generated, a storage start signal is output to the control unit 130. The control unit 130 receives this signal and sets the memory 142 in the storage unit 140 to a state in which the coordinate data can be written (write mode). To do. Then, the data generation means 120 further subdivides each line segment from the start point to the end point, calculates the coordinate data of a plurality of trajectory points including the start point and the end point, and obtains the respective coordinate data. The addresses are attached and sequentially stored in the memory 142. The coordinate data of the trajectory point generated at this time also includes point data information indicating whether it is the coordinate data of the start point, the coordinate data of the end point, or the coordinate data of the middle point. Yes.

  The control unit 130 can read the data from the memory 142 when outputting the coordinate data stored in the memory 142 in response to an external marking start trigger signal (not shown). In addition to setting to (read mode), a counter control signal is output to the counter 141 in the storage unit 140. In response to this control signal, the counter 141 sequentially counts the addresses in the memory 142 to read out and output the coordinate data. The coordinate data output from the memory 142 is sent from the line driver / receiver 50A of the controller unit 100 to the D / A conversion unit 230 via the line driver / receiver 50B of the head unit 200, and also to the control unit 130. Sent out.

  In the control means 130, an ON / OFF signal, which will be described later, is used as a laser light source based on whether the coordinate data sent from the line driver / receiver 50 </ b> A is start point coordinate data or end point coordinate data. In response to this control signal, the laser light source 210 turns on / off the laser light. The D / A conversion means 230 converts the sent coordinate data into a voltage and outputs it to the servo circuit 240. In addition, the D / A conversion means 230 also provides a window comparator 253, which is a first discrimination means provided in the approach state detection means 250 Output.

  The servo circuit 240 receives this voltage to drive the circuit and controls the angle of the galvano mirror 220, thereby changing the angle of the galvano mirror 220 and controlling the direction of the laser light from the laser light source 210. Thus, the laser beam irradiated onto the workpiece 300 is two-dimensionally scanned. An angle detection means 251 is provided in the servo circuit 240. This angle detection means 251 detects the angle of the galvanometer mirror 220 and feeds back a voltage corresponding to this angle into the servo circuit 240. Is also output to the window comparator 253.

  The servo circuit 240 is also provided with a differentiating circuit 252 as speed detecting means, which converts the voltage from the angle detecting means 251 into a voltage corresponding to the scanning speed of the galvanometer mirror 220, The voltage is fed back to the servo circuit 240, and this voltage is also output to the comparator 254, which is a second discrimination means provided in the approach state detection means 250.

  The window comparator 253 compares the voltage difference from the angle detection unit 251 with the input voltage from the D / A conversion unit 230 with a predetermined first reference voltage, and the result is converted into a first binarization. The first binarized signal is input from the line driver / receiver 50B of the head unit 200 to the control means 130 via the line driver / receiver 50A of the controller unit 100. In the comparator 254, the input voltage from the differentiating circuit 252 is compared with a predetermined second reference voltage, and the result is output as a second binarized signal. The data is input from the line driver / receiver 50B of the head unit 200 to the control unit 130 via the line driver / receiver 50A of the controller unit 100.

  When the coordinate data sent from the memory 142 via the line driver 50C is the coordinate data of the start point and the end point, the control unit 130 accepts the binarized signal and receives the binary signal from the D / A conversion unit 230. When the voltage difference from the angle detection means 251 with respect to the voltage is within a predetermined first reference voltage and the voltage from the differentiating circuit 252 is within the predetermined second reference voltage, coordinate data is sequentially transmitted. In this way, when the determination result is other than that, the counter 141 counting the address of the memory 142 is repeatedly counted with the address of the coordinate data of the start point or the end point.

  Further, when the coordinate data sent from the memory 142 via the line driver / receiver 50A is the starting point coordinate data, the control means 130 accepts the binarized signal and receives the D / A conversion means. When the voltage difference from the angle detection means 251 with respect to the voltage from 230 is within a predetermined first reference voltage and the voltage from the differentiating circuit 252 is within a predetermined second reference voltage, the coordinate data is sequentially In this case, the address of the memory 142 is counted up, the next coordinate data is sent out, and a laser control signal (ON signal) is given to the laser light source 210 to emit laser light. On the other hand, if the coordinate data sent from the memory 142 via the line driver 50 is the coordinate data of the end point, this binarized signal is accepted and angle detection with respect to the voltage from the D / A conversion means 230 is received. When the voltage difference from the means 251 is within a predetermined first reference voltage and the voltage from the differentiating circuit 252 is within a predetermined second reference voltage, the laser light source 210 receives a laser control signal (OFF signal). ) And turn off the laser beam.

Next, the optical system 700 will be described with reference to FIG.
The optical system 700 according to this embodiment is configured to change a beam diameter of a laser beam from the laser light source 210, and the first and second laser beams L1 and L2 from the laser beam emitted from the beam expander 710. The auxiliary optical system 720 generates and changes the beam diameter B2 of the second laser light L2.

The beam expander 710 has a known structure as shown in FIG. 2, and the beam diameter can be changed by changing the distance between the diverging lens 711 and the collimator lens 712.
The auxiliary optical system is configured as an optical unit integrally including half mirrors 721 and 722, total reflection mirrors 723 and 724, and a diverging lens 725.
The laser beam from the beam expander 710 is branched to the two optical axes LC1 and LC2 by the half mirror 721, one (first laser beam L1) is directed to the half mirror 722, and the other (second laser beam L2) is all. Reflects the reflection mirrors 723 and 724 and travels toward the diverging lens 725. The first and second laser beams L 1 and L 2 that have passed through the half mirror 721 and the diverging lens 725 are arranged on the same optical axis by the half mirror 722 and travel toward the galvanometer mirror 220.

  The diverging lens 725 is mounted on an actuator (not shown) that can move in the direction along the optical axis LC2 based on a drive signal from the control means 130, and the diverging lens 725 moves along the optical axis along with the operation of this actuator. It can move on LC2. Accordingly, the beam diameter B2 of the second laser light L2 on the print area MA of the workpiece 300 changes depending on the position of the diverging lens 725.

  Further, the half mirrors 721 and 722 are actuators (not shown) that move the half mirrors 721 and 722 in a direction orthogonal to the optical axis LC1 of the first laser light L1 based on a control signal from the control unit 130. For example, when a marking process is performed on glass or the like, it is arranged at a position (entrance position) that has entered on the optical axis LC1. It is arranged at a shifted position (retreat position).

The operation of the present invention will be described below.
When marking a super-hardened material made of carbon steel, such as iron-based material, or glass, a laser beam with a markable energy fluence (hereinafter referred to as “fluence”) is suddenly applied to the print area MA. There is a risk of cracking due to shock. Therefore, in the present embodiment, first, the printing position M and its surroundings are heated, and when the temperature rises, a marking process is performed to avoid thermal shock.
“Energy fluence” indicates the amount of energy per unit area, and the unit is, for example, J / m ² or J / cm ² , and J / cm ² is often used.

In this embodiment, the fluence is increased by gradually moving the diverging lens 725 from the mirror 724 side to the half mirror 722 side to reduce the beam diameter B2 on the print region of the second laser light L2. Specifically, at the start of printing, the fluence φ0 of the condensing position (printing position M) of the first laser beam L1 is set to a fluence that is incapable of marking. That is, the sum φ0 of the fluences φ1 and φ2 of the first laser beam L1 and the second laser beam L2 is set to be less than the fluence φa that cannot be marked. When the diverging lens 725 is moved toward the half mirror 722 with the passage of time, the beam diameter B2 of the second laser light L2 is reduced, and the fluence φ0 of the second laser light L2 on the printing area MA is increased. After a predetermined time (heating time Ta) has elapsed, the fluence φ0 at the print position M becomes equal to or higher than the fluence φa that can be marked, and the marking process is performed. And predetermined fluence (phi) b is maintained (refer FIG.3 and FIG.4).
Therefore, the moving speed of the diverging lens 725 may be adjusted so that the heating time Ta is a time that does not cause thermal shock to the workpiece 300. The heating time Ta may be set to a theoretically assumed time based on the material of the workpiece 300, or may be set experimentally by actually irradiating the workpiece 300 with the laser beams L1 and L2. Alternatively, the heating time Ta may be set by setting the theoretically assumed time and then irradiating the laser.

Further, a method of increasing the fluence φ0 by increasing the output of the laser light source 14 may be taken (see FIG. 5). Also in this case, as described above, the heating time Ta based on the theoretical value, the experimental value, or both can be set.
Furthermore, the fluence may be increased by increasing the output of the laser light source 14 while moving the diverging lens 725.

  Further, in the above operation, the half mirrors 721 and 722 are arranged at the approach positions so that the first and second laser beams L1 and L2 are emitted. However, the workpiece W is free from cracks due to thermal shock. When the marking process is performed, the half mirrors 721 and 722 are arranged at the retracted positions, and the marking process can be performed without performing the heating operation by emitting the first laser beam.

As another configuration, the half mirror 722 is replaced with a polarization beam splitter, a quarter wavelength plate 726 is disposed between the half mirror 721 and the total reflection mirror 723, and a polarization beam splitter that transmits only P-polarized light. A quarter-wave plate 726 may be disposed between the first reflection mirror 726 and the total reflection mirror 726.
In such a configuration, when laser light that is linearly polarized light (for example, P-polarized light) passes through the half mirror 721, it is branched into first and second laser light. Among these, since the first laser beam is P-polarized light, it passes through the polarization beam splitter. On the other hand, since the second laser light passes through the quarter wavelength plate twice and becomes S-shaped wave, it is reflected by the polarization beam splitter and is on the same optical axis as the optical axis LC1 of the first laser light. Will be placed. With such a configuration, the loss of the first laser beam and the second laser beam is extremely small as compared with the case where the half mirror 722 is used, which contributes to power saving.
Further, the quarter wavelength plate 726 may be provided on one of the light reflection surfaces of the total reflection mirror 723 or 724. In this case, the light is transmitted through the quarter-wave plate before entering the total reflection mirror 723 (724), and further reflected through the total reflection mirror 723 (724) and then transmitted through the quarter-wave plate to obtain P-polarized light. And reflected by the polarization beam splitter.

According to the embodiment, first, the print position M and its surroundings are heated by irradiating the work 300 with the first and second laser beams L1 and L2 at a fluence that is not marked, and the first and second laser beams L1 and L2 are heated. Marking is performed by irradiating the laser beam L1, L2 having a fluence sufficient for marking to the printing position M irradiated with the laser beams L1, L2. In this way, high print quality can be maintained without causing cracks in the workpiece 300. Further, since the heat treatment and the marking are performed simultaneously, the time for the marking process can be greatly reduced.
Furthermore, when the end point is reached in the marking of each line segment, it is preferable to provide a cooling period as a marking impossible state having an energy fluence φa or less.

<Embodiment 2>
As shown in FIGS. 6 and 7, the present embodiment is different from the first embodiment in that the optical system 700 includes a beam expander 710 and a compound lens 730 having a disk shape. Since other configurations are the same as those of the above embodiment, only different portions will be described.
The compound lens 730 has a converging lens portion 731 having a converging function at the center thereof, and the periphery thereof includes a light transmission portion 732 that transmits incident light as it is.
When the laser beam from the beam splitter 710 enters the compound lens 730, the component incident on the converging lens unit 731 is converted into convergent light (second laser beam L2) and condensed in the middle, and then diverges while divergence. Head to 220. On the other hand, the component incident on the light transmitting portion 732 is transmitted as it is and travels toward the galvanomirror as parallel light (first laser light L1).

  Therefore, it is only necessary to emit laser light while moving the compound lens 830 from the beam expander 710 side to the galvano mirror device 220 side. Then, since the condensing position of the second laser beam L2 moves toward the galvanometer mirror device 220, the beam diameter B2 of the second laser beam L2 on the print area MA of the workpiece W is reduced and the fluence φ2 is increased. As a result, the fluence φ0 at the irradiation position (printing position M) of the first laser beam L1 increases from the fluence φa below the level where marking is impossible to the fluence φa above the level where marking is possible, and the marking process is performed. Become.

Further, the fluence φ0 at the printing position can be increased by increasing the beam diameter of the laser light emitted from the beam expander 710.
For example, the distance between the diverging lens 711 and the beam expander 712 is set to d1 at the start of printing, and is set to d2 longer than d1 after the heating time Ta has elapsed. Then, when the distance is d1, the beam diameter is w1, and when the distance is d2, the beam diameter is w2, which is larger than the beam diameter w1. Further, the ratio of the first laser beam L1 and the second laser beam L2 when the beam diameter is w1 (the ratio A of the cross-sectional area when passing through the compound lens 730. “Ratio A = discontinuation of the first laser beam”. "Area / cross-sectional area of second laser beam") is defined as A1, and the ratio when the beam diameter is w2 is defined as A2, which is larger than A1. The beam expander 710 is controlled so that the fluence φ0 when the ratio A becomes A2 is set to be equal to or greater than the fluence φa that can be marked, and the time for the ratio to shift from A1 to A2 becomes the heating time Ta. It is good.
Further, since the beam diameter of the first laser beam L1 is increased in the process of changing the ratio from A1 to A2, it is a well-known fact that the spot diameter B1 at the printing position M is thereby reduced. Specifically, an inversely proportional relationship is established in which the spot diameter B1 decreases as the beam diameter increases. Therefore, the distance between the beam expander 710 and the compound lens 730 is kept constant, and the operation similar to the above is performed by controlling to increase the beam diameter of the laser light emitted from the beam expander 710. (See FIG. 7).
Of course, a method of increasing only the output of the laser light source 210 may be used, or it may be used in combination with the above method.

<Embodiment 3>
In the present embodiment, laser light attenuation means 727 is arranged between the half mirrors 721 and 722 and between the mirrors 723 and 724 in the first embodiment.
The laser light attenuating means 727 can be constituted by, for example, a liquid crystal shutter or an attenuating filter that can vary the attenuation factor, and can be operated in conjunction with the above embodiment (FIG. 8). reference).
Further, as shown in FIG. 9, the laser light attenuating means 727 may be provided only between the half mirrors 731 and 732, or the laser light attenuating means may be provided between the mirrors 723 and 724 as shown in FIG. You may comprise.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In this embodiment, after the marking operation, the output level is lowered and the cooling period for scanning the marking portion is provided again. However, the present invention is not limited to this, and the cooling period may not be provided. . However, if a cooling period is provided, characters, symbols, figures, and the like marked by the marking operation are not rapidly cooled, and the effect of preventing the occurrence of cracks can be further improved.
(2) In the present embodiment, the laser light source uses a CO2 laser of carbon dioxide gas having a wavelength of 10.6 μm in consideration of economy and the like, taking an infrared laser having a wavelength of 4.8 μm or more that does not pass through glass as an example. However, the present invention is not limited to this, and any laser that does not transmit glass may be used, and laser light in an ultraviolet region having a very short wavelength may be used.
(3) The half mirrors 721 and 722 in the above embodiment may be changed to various ratios such as a ratio of transmittance to reflectance of 8: 2 or 7: 2. In particular, since the energy fluence of the first laser beam is preferably larger than the energy fluence of the second laser beam in performing the marking process, the above-described configuration is extremely useful.
(4) In the third embodiment, the liquid crystal shutter may be configured to change its transmittance based on a control signal from the outside. In this case, the selection direction of the direction of changing the energy fluence is selected. Therefore, optimal adjustment can be expected.

1 is a block diagram conceptually showing the configuration of a laser marking apparatus according to a first embodiment. Conceptual diagram showing the configuration of the optical system Explanatory diagram conceptually showing heating and printing operations A graph showing changes in fluence over time A graph showing changes in fluence over time Schematic diagram showing the configuration of the optical system in the laser marking device according to the second embodiment Explanatory drawing which explains the change method of a spot diameter notionally Schematic diagram showing the configuration of the optical system in the laser marking device according to the third embodiment Schematic diagram showing the configuration of the optical system in the laser marking device according to the third embodiment Schematic diagram showing the configuration of the optical system in the laser marking device according to the third embodiment Conceptual diagram showing the conventional configuration Conceptual diagram showing the conventional configuration

Explanation of symbols

DESCRIPTION OF SYMBOLS 210 ... Laser light source 220 ... Galvano mirror apparatus 300 ... Work 710 ... Beam expander 720 ... Auxiliary optical system 800 ... Converging lens MA ... Printing area M ... Printing position L1 ... 1st laser beam L2 ... 2nd laser beam LC1 ... Optical axis of the first laser beam LC2 ... Optical axis of the second laser beam

Claims (6)

The laser light from the laser light emitting means is irradiated onto the print area of the object to be printed via the galvano mirror device and the converging lens, and the galvano mirror device is operated to scan the laser light on the print area. In a laser marking device that prints marking information such as characters, symbols, figures, etc. on the printing area,
The laser beam emitting means has a first laser beam condensed at a first spot diameter on the print area, and a second spot diameter that is also an energy fluence that cannot be marked on the print area, And a second laser beam that is irradiated onto a region including the condensing position of the first laser beam, and the energy fluence in the first or second laser beam is At the start point of each line segment element in the marking information, the overlapping position of the spot of the first laser beam and the spot of the second laser beam is increased from an energy fluence that cannot be marked to an energy fluence that can be marked. Energy fluence change for changing the energy fluence of the first or second laser beam Laser marking apparatus characterized by comprising a stage. The laser marking apparatus according to claim 1, wherein the laser beam emitting unit includes one laser light source, and the energy fluence changing unit is configured to change a laser output of the laser light source. The energy fluence changing means splits the optical axis of the laser light from the laser light source into two optical axes to generate the first and second laser lights, and
Beam diameter changing means for changing one of the first and second laser beams;
3. The laser marking according to claim 1, wherein the first and second laser beams are arranged on the same optical axis and are composed of a combining unit that guides the first and second laser beams to the galvanometer mirror device. 4. apparatus. The energy fluence changing means includes a beam expander and a compound lens having different focal lengths, and changes a distance between the beam expander and the compound lens or a beam diameter of laser light emitted from the beam expander. Thus, the energy fluence of one or both of the first and second laser beams having different focal lengths emitted from the compound lens is changed. Item 3. The laser marking device according to Item 2. The energy fluence changing unit is configured by a laser beam attenuating unit that is arranged on at least one of the optical axis of the first laser beam or the optical axis of the second laser beam and attenuates the laser beam. The laser marking device according to claim 3 or 4, wherein the laser marking device is provided. 6. The laser marking apparatus according to claim 1, wherein the object to be marked is a super-curing material member or a glass member.

Images