JP2023050872A - Laser processing device and laser processing method - Google Patents

Abstract

To provide a technique for determining whether or not output fluctuation is generated in a laser beam from a laser oscillator, without obtaining a reference value according to a processing object in advance.SOLUTION: A CPU 61 of a laser processing device 1 executes: threshold setting processing (S18) for calculating a threshold of a proper laser output on the basis of an output value of a laser beam measured according to a parameter 110 during test printing in which laser processing is performed, and for storing the threshold in a RAM 62; and determination processing (S26) for determining whether or not output fluctuation is generated in a laser beam, on the basis of the output value of the laser beam measured according to the parameter 110 when laser processing is performed, and the threshold stored in the RAM 62 according to the threshold setting processing.SELECTED DRAWING: Figure 3

Description

The present application relates to a technique for laser processing an object.

In Patent Document 1, the pulse energy of the laser output from a carbon dioxide laser is measured, the measured value is compared with a predetermined reference value, and the laser power of the carbon dioxide laser is adjusted according to the comparison result. A laser power stabilizer is described.

JP-A-11-261146

However, in the laser power stabilizing device described in Patent Document 1, it is necessary to set a different reference value for each object to be processed. I had to, and it was troublesome.

An object of the present application is to provide a technique that makes it possible to determine whether or not the output power of a laser beam from a laser oscillator is fluctuating without previously obtaining a reference value according to an object to be processed.

In order to achieve the above object, the laser processing apparatus of the present application has a laser oscillator that oscillates laser light, an optical system that guides the laser light to an exit port as processing laser light, and a light receiving section. A power meter capable of measuring the output value of the laser light based on part of the laser light guided to the light receiving unit by the system, a memory, and a control unit, the control unit performing laser processing. Threshold setting processing for calculating an appropriate laser output threshold value based on the laser light output value measured by the power meter at the operation timing and storing it in memory, and measuring with the power meter at the second operation timing for laser processing. a determination process of determining whether or not the laser light output fluctuates based on the output value of the laser light obtained and the threshold value stored in the memory by the threshold setting process. .

According to the present application, it is possible to determine whether or not the output of the laser beam from the laser oscillator is fluctuating without previously obtaining a reference value according to the object to be processed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the laser processing apparatus which concerns on one Embodiment of this application. 2 is a block diagram showing a control configuration of the laser processing apparatus of FIG. 1; FIG. 2 is a flow chart showing a procedure of laser power measurement/adjustment processing executed by the laser processing apparatus of FIG. 1, particularly by a CPU; FIG. 4 is a flow chart showing a procedure subsequent to the laser power measurement/adjustment process of FIG. 3; FIG. FIG. 5 is a flow chart showing a procedure subsequent to the laser power measurement/adjustment process of FIG. 4; FIG. FIG. 4 is a flowchart showing a detailed procedure of a measurement object determination process included in the laser power measurement/adjustment process of FIG. 3; FIG. FIG. 2 is a diagram showing an example of measurement results by a power meter included in the laser processing apparatus of FIG. 1;

Hereinafter, embodiments of the present application will be described in detail based on the drawings. FIG. 1 shows a schematic configuration of a laser processing apparatus 1 according to an embodiment of the present application, and FIG. 2 shows a control configuration of the laser processing apparatus 1. As shown in FIG. 1 and 2, a part of the basic configuration is omitted, and the dimensional ratios of the drawn parts are not necessarily accurate. Moreover, in FIG. 1, the vertical direction is as shown in the figure.

As shown in FIG. 2, the laser processing apparatus 1 is composed of a printed information creating section 2 and a laser processing section 3. As shown in FIG. The print information creation unit 2 is composed of a personal computer, a PLC (Programmable Logic Controller), and the like.

The laser processing unit 3 two-dimensionally scans the processing surface 8 of the processing object 7 with the processing laser beam P to perform marking (printing) processing. The laser processing unit 3 has a laser controller 6 .

The laser controller 6 is composed of a computer, and is connected to the print information creating section 2 via, for example, USB, Ethernet, wireless LAN, RS-232C, etc. so as to be able to communicate bidirectionally. The laser controller 6 drives and controls the laser processing unit 3 based on the print information 67, parameters, various instruction information and the like transmitted from the print information creation unit 2. FIG.

The laser processing unit 3 includes, as shown in FIG. lens 19, etc., and is covered with a substantially rectangular parallelepiped housing cover (not shown).

The laser oscillation unit 12 is composed of a laser oscillator 21 and the like. The laser oscillator 21 is composed of a CO2 laser, a YAG laser, or the like, and emits processing laser light P. As shown in FIG. The diameter of the processing laser beam P is adjusted (eg, enlarged) by a beam expander (not shown).

The emitted processing laser beam P is incident on the beam splitter 100 . The beam splitter 100 transmits a part of the incident processing laser beam P, for example, about 1%, and supplies it to the power meter 110 . The processing laser beam P that is not transmitted by the beam splitter 100 , that is, most of the emitted processing laser beam P in this embodiment is reflected by the beam splitter 100 and enters the reflecting mirror 101 . The reflecting mirror 101 reflects all the incident processing laser light P and supplies it to the dichroic mirror 102 .

The guide light section 15 is composed of a visible semiconductor laser 28 or the like. The visible semiconductor laser 28 emits guide light Q, which is visible coherent light, such as red laser light. The guide light Q is collimated by a lens group (not shown) and is scanned two-dimensionally to form, for example, an image of a printing pattern to be marked (printed) by the processing laser beam P (hereinafter referred to as an "object"). ), a rectangular image or the like surrounding the object is drawn on the processing surface 8 of the processing object 7 in a locus (temporal afterimage due to reflection). In other words, the guide light Q has no marking (printing) processing ability.

The wavelength of the guide light Q is different from the wavelength of the processing laser light P. As shown in FIG. In this embodiment, for example, the wavelength of the processing laser beam P is 1064 nm, and the wavelength of the guide beam Q is 650 nm.

The dichroic mirror 102 allows almost all of the incident processing laser beam P to pass therethrough. Further, in the dichroic mirror 102, the guide light Q is incident at an incident angle of 45 degrees at a substantially central position through which the processing laser light P is transmitted, and is reflected onto the optical path of the processing laser light P at a reflection angle of 45 degrees. . The reflectance of the dichroic mirror 102 has wavelength dependence. Specifically, the dichroic mirror 102 is surface-treated to have a multilayer structure of dielectric layers and metal layers, and has a high reflectance with respect to the wavelength of the guide light Q. is configured to transmit most (99%) of the

1 indicates the optical axis 10 of the processing laser beam P and the guide beam Q. As shown in FIG. Also, the direction of the optical axis 10 indicates the path direction of the processing laser beam P and the guide beam Q. As shown in FIG.

The optical system 70 has a first lens 72 , a second lens 74 and a moving mechanism 76 . In the optical system 70 , the processing laser beam P and the guide beam Q that have passed through the dichroic mirror 102 enter and pass through the first lens 72 . At that time, the light diameters of the processing laser light P and the guide light Q are reduced by the first lens 72 . The processing laser beam P and the guide beam Q that have passed through the first lens 72 enter and pass through the second lens 74 . At that time, the processing laser beam P and the guide beam Q are collimated by the second lens 74 . The moving mechanism 76 includes an optical system motor 80 and a rack and pinion (not shown) that converts the rotational motion of the optical system motor 80 into linear motion. The lens 74 is moved in the path direction of the processing laser beam P and the guide beam Q. As shown in FIG.

The moving mechanism 76 may be configured to move the first lens 72 instead of the second lens 74, or the first lens 72 and the second lens 74 may be moved such that the distance between the first lens 72 and the second lens 74 is changed. A configuration in which both the lens 72 and the second lens 74 are moved may be used.

The galvanometer scanner 18 two-dimensionally scans the processing laser beam P and the guide beam Q that have passed through the optical system 70 . In the galvano scanner 18, a galvano X-axis motor 31 and a galvano Y-axis motor 32 are mounted so that their respective motor shafts are perpendicular to each other, and scanning mirrors 18X and 18Y mounted on the tips of the respective motor shafts are arranged inside. facing each other. By rotating the scanning mirrors 18X and 18Y by controlling the rotation of the motors 31 and 32, the processing laser beam P and the guide beam Q are two-dimensionally scanned. The two-dimensional scanning directions are the X direction and the Y direction.

The f.theta. Therefore, the machining laser beam P and the guide beam Q are two-dimensionally scanned in the X direction and the Y direction on the machining surface 8 of the object 7 by controlling the rotation of the motors 31 and 32 .

The processing laser light P and the guide light Q have different wavelengths. Therefore, when the distance between the first lens 72 and the second lens 74 in the optical system 70 is constant, the position where the processing laser light P and the guide light Q converge (hereinafter referred to as "focus position F") is , differ in the vertical direction. Therefore, by adjusting the distance between the first lens 72 and the second lens 74 in the optical system 70, the focal position F of the processing laser beam P and the guide beam Q is adjusted to the processing surface 8 of the processing object 7. can be adjusted to

Similarly, when the position of the processing surface 8 of the object 7 is different in the vertical direction, the focal positions F of the processing laser light P and the guide light Q are the same as those of the first lens 72 and the second lens in the optical system 70. 74 is adjusted to match the processing surface 8 of the workpiece 7 .

The camera 103 is provided near the f.theta. As a result, the camera 103 captures, for example, the guide light Q irradiated onto the processing surface 8 of the processing object 7 and displays it on a liquid crystal display (LCD) 56, which will be described later. It may be possible for the user to check whether the alignment with is appropriate.

Next, the control configuration of the print information generating section 2 and the laser processing section 3 that constitute the laser processing apparatus 1 will be described with reference to FIG. First, the control configuration of the laser processing unit 3 will be described.

As shown in FIG. 2, the laser processing unit 3 includes a laser controller 6, a galvano controller 35, a galvano driver 36, a laser driver 37, a semiconductor laser driver 38, an optical system driver 78, a camera 103, a power meter 110, an A/D converter. 112, a temperature sensor 120, and the like. A laser controller 6 controls the entire laser processing unit 3 . The laser controller 6 is electrically connected to the galvanometer controller 35, the laser driver 37, the semiconductor laser driver 38, the optical system driver 78, and the like. An external print information generating unit 2 is connected to the laser controller 6 and the camera 103 so as to be capable of two-way communication. The laser controller 6 is configured to be able to receive each piece of information (for example, print information 67, parameters for the laser processing unit 3, various instruction information from the user, etc.) transmitted from the print information creation unit 2. FIG. The camera 103 is configured to be able to receive each piece of information (for example, imaging instruction information, etc.) transmitted from the print information creation unit 2, and is configured to be able to transmit captured images to the print information creation unit 2.

The laser controller 6 includes a CPU 41, a RAM 42, a ROM 43, and the like. The CPU 41 is an arithmetic device and control device that controls the entire laser processing unit 3 . The CPU 41, RAM 42, and ROM 43 are interconnected by a bus (not shown) to exchange data with each other.

The RAM 42 is for temporarily storing various calculation results calculated by the CPU 41, printing pattern (XY coordinate) data, and the like.

The ROM 43 stores various programs. For example, the XY coordinate data of the print pattern is calculated based on the print information 67 sent from the print information creation unit 2 and stored in the RAM 42 as processed data. Programs and the like are stored. In addition to the programs described above, the various programs include, for example, various delay values, the thickness, depth and number of print patterns corresponding to the print information 67 input from the print information creation unit 2, laser oscillator 21 laser output, the laser pulse width of the processing laser beam P, the scanning speed of the processing laser beam P by the galvanometer scanner 18, and the scanning speed of the guide beam Q by the galvanometer scanner 18, etc. A program for storing in the RAM 42 various parameters. etc. Further, the ROM 43 stores parameters for distortion correction and status information (error information, number of times of processing, processing time, etc.) of the galvanometer scanner 18 and the laser processing device 1 .

The CPU 41 performs various calculations and controls based on various programs stored in the ROM 43 .

The CPU 41 outputs to the galvano controller 35 processing data, the speed of scanning the guide light Q by the galvano scanner 18 , galvano scanning speed information indicating the speed of scanning the processing laser beam P by the galvano scanner 18 , and the like. The CPU 41 also outputs laser drive information indicating the laser output of the laser oscillator 21 set based on the processing data, the laser pulse width of the processing laser beam P, and the like to the laser driver 37 .

The CPU 41 outputs to the semiconductor laser driver 38 an ON signal instructing the start of lighting of the visible semiconductor laser 28 or an OFF signal instructing the extinguishing of the visible semiconductor laser 28 .

The galvano controller 35 calculates the drive angle, rotation speed, etc. of the galvano X-axis motor 31 and the galvano Y-axis motor 32 based on each information input from the laser controller 6 (for example, processing data, galvano scanning speed information, etc.). Then, motor drive information indicating the drive angle and rotation speed is output to the galvano driver 36 . The galvano driver 36 drives and controls the galvano X-axis motor 31 and the galvano Y-axis motor 32 based on the motor driving information input from the galvano controller 35 to two-dimensionally scan the processing laser beam P and the guide beam Q. FIG.

The laser driver 37 drives the laser oscillator 21 based on the laser output of the laser oscillator 21 input from the laser controller 6 and the laser drive information indicating the laser pulse width of the processing laser beam P and the like. The semiconductor laser driver 38 drives the visible semiconductor laser 28 based on the ON signal or OFF signal input from the laser controller 6 .

The optical system driver 78 drives and controls the optical system motor 80 based on the information input from the laser controller 6 to move the second lens 74 .

The power meter 110 has, for example, a structure including a photodetector such as a photodiode sensor, and outputs an analog voltage value corresponding to the intensity of a portion of the incident processing laser beam P. The A/D converter 112 is provided on the output side of the power meter 110 and converts the analog voltage value output by the power meter 110 into a digital value. The A/D converter 112 is connected with the laser controller 6 . Therefore, the print information generator 2 can read the output voltage value of the power meter 110 output from the A/D converter 112 via the laser controller 6 . The power sensor may be a so-called thermal power sensor that utilizes the thermoelectric effect.

Also, the temperature sensor 120 measures the temperature of the laser oscillator 21 . The temperature sensor 120 is also electrically connected to the print information creation section 2 , and the print information creation section 2 can know the temperature of the laser oscillator 21 from the temperature sensor 120 .

Next, the circuit configuration of the print information creating section 2 will be described. The print information creation section 2 includes a control section 51, an input operation section 55, a liquid crystal display (LCD) 56, a CD-ROM drive 58, and the like. An input operation unit 55, a liquid crystal display 56, a CD-ROM drive 58, and the like are connected to the control unit 51 via an input/output interface (not shown).

The input operation unit 55 includes a mouse and a keyboard (not shown) and the like, and is used, for example, when the user inputs various instruction information. In addition, the input operation unit 55 allows the user to specify an operation mode for the laser power measurement/adjustment process, which will be detailed later.

The CD-ROM drive 58 reads various data, various application software, etc. from the CD-ROM 57 .

The control unit 51 controls the entire print information creation unit 2, and is capable of executing image processing, which will be described later, using a known technique. ".) 66 etc. are provided. The CPU 61 is an arithmetic device and a control device that controls the print information creation section 2 as a whole. CPU 61, RA
The M62 and ROM 63 are interconnected by a bus (not shown) and exchange data with each other. Furthermore, the CPU 61 and the HDD 66 are connected via an input/output interface (not shown), and exchange data with each other.

The RAM 62 is for temporarily storing various calculation results and the like calculated by the CPU 61 . The RAM 62 also stores print information 67 . The print information 67 is input by the user through the input operation unit 55, but may be read from the CD-ROM 57 by the CD-ROM drive 58, or may be input from outside the laser processing apparatus 1 via an input/output interface (not shown). may be entered. Note that the print information 67 includes, for example, the position, content, type, etc. of the object in addition to the items related to the data described above. The ROM 63 stores various programs and the like. Further, the ROM 63 stores data such as the start point, end point, focal point, curvature, etc. of each character composed of a straight line and an elliptical arc for each type of font. The ROM 63 also stores a control program 65 including a laser power measurement/adjustment process, which will be described later with reference to FIGS. 3 to 5, a data table 68, and the like.

The HDD 66 stores various application software programs, various data files, and the like.

Control processing executed by the laser processing apparatus 1 configured as described above will be described in detail with reference to FIGS. 3 to 7. FIG. 3 to 5 show procedures of laser power measurement/adjustment processing executed by the laser processing apparatus 1, especially the CPU 61. FIG. The laser power measurement/adjustment process is the laser power measured by the power meter 110 during test printing (an example of “first operation timing”) before the laser processing apparatus 1 performs actual printing (an example of “main processing”). Based on the laser power of the oscillator 21, the appropriate laser power threshold of the laser oscillator 21 is calculated, and the laser power of the laser oscillator 21 measured by the power meter 110 at the time of actual printing (an example of "second operation timing") This is a process for adjusting the current supplied to the laser oscillator 21 so that the laser power recovers to the desired value when the power falls below the threshold. In the laser power measurement/adjustment process, there is a fully automatic adjustment mode in which everything from threshold calculation to adjustment of the current supplied to the laser oscillator 21 is performed completely automatically, and a user selection mode in which the user is requested to perform a predetermined selection operation. A non-adjustment mode in which the laser power is measured but not adjusted is provided, and the user can select either mode. The operation of selecting one of these three modes may be performed by the user through the input operation unit 55, for example. The mode selected by the user is stored in a mode storage area (not shown) secured in the RAM 62, for example. Note that the laser power measurement/adjustment process is started, for example, in response to a user's instruction from the input operation unit 55 to start the process. Henceforth, in description of the procedure of each process, a step is described with "S".

In FIG. 3, the CPU 61 first instructs the laser controller 6 to start energizing the laser oscillator 21 (S10). In response to this, the laser controller 6 , especially the CPU 41 starts supplying power to the laser oscillator 21 .

Next, the CPU 61 determines whether or not the temperature of the laser oscillator 21 has stabilized (S12). This determination is made based on the temperature obtained from the temperature sensor 120 (see FIG. 2). A state in which the temperature of the laser oscillator 21 is stabilized means a state in which the laser oscillator 21 reaches the saturation temperature.

In S12, the CPU 61 waits until the temperature of the laser oscillator 21 stabilizes (S12: NO), and when the temperature of the laser oscillator 21 stabilizes (S12: YES), the CPU 61 advances the process to the next step S14. In general, the laser oscillator 21 is easily affected by temperature, and even in a normal state, there is a possibility that the output may change until reaching the saturation temperature. Therefore, the following processing is performed after waiting for the timing when the temperature reaches the saturation temperature and the laser output is stabilized.

In S14, the CPU 61 determines whether or not the fully automatic adjustment mode is set. In this judgment, the CPU 61 reads the mode stored in the mode storage area and judges whether or not the read mode is the full automatic adjustment mode.

In the judgment of S14, if the fully automatic adjustment mode is set (S14: YES), the CPU 61 executes measurement object determination processing (an example of "specific range setting processing") (S16). FIG. 6 shows the detailed procedure of this measurement target determination process. In FIG. 6, the CPU 61 first stores print data (an example of "print data") instructed by the user, for example, from the input operation unit 55 in a work area (not shown) of the RAM 62 (S100).

Next, the CPU 61 selects, from the print data stored in the work area, characters excluding the first character that have a long laser-on time (an example of a "specific range") as objects to be measured (S102). For example, if "manufacturing number XXXX" (where X is an integer value from 0 to 9) is specified as the print data, then the object to be measured is "manufacturing", which has a long laser-on time "one point". selected. FIG. 7 shows measurement results obtained from the power meter 110 when the same character, for example, "8", is repeatedly printed by the laser processing apparatus 1 of the present embodiment, specifically, changes in the voltage value. there is As can be seen from this measurement result, in the laser processing apparatus 1 of the present embodiment, the laser power when the same character is first printed from the resting state includes a transient variation in the output, and the second and subsequent characters are printed. It is lower than the laser power at that time. For this reason, the first character is excluded from the measurement targets. In addition, the measurement target for characters with strokes with a long laser-on time is that the measurement time (or the number of sampling times for measurement) during the laser-on period is increased to calculate the laser power threshold during test printing and during actual printing. This is because it is desired to more accurately determine whether or not the laser power at is below the threshold value.

Returning to FIG. 6, next, the CPU 61 determines whether or not the time for jumping between adjacent images in one character selected as a measurement object is shorter than the time T (S104). Here, the time for jumping between adjacent images means the laser off time from the end of printing of the image to be printed first in the adjacent images to the start of printing of the next image. Therefore, in the judgment of S104, the CPU 61 judges whether or not this laser-off time is shorter than the time T.

In the judgment of S104, if this laser-off time is shorter than the time T (S104: YES), the CPU 61 also includes the laser-on time when printing adjacent images in the calculation (S106).

Next, the CPU 61 makes the same determination as the determination in S104 above for adjacent character strings (S108). Specifically, the CPU 61 determines that the laser-off time from the end of printing of the last stroke of the character to be printed first in the adjacent character string to the start of printing of the first stroke of the next character is less than the time T. or not. In this judgment, if the laser-off time is shorter than the time T (S108: YES), the CPU 61 makes the same judgment as the above S104 for the next character (S110). In this determination, if the laser-off time from the end of printing of the image to be printed first in the next one character to the start of printing of the next image is less than the time T (S110: YES), the CPU 61 includes the laser-on time when printing adjacent images in the calculation (S112), and then returns the process to S110.

On the other hand, if the laser-off time is not less than the time T in the judgment of S110 (S1
10: NO), the CPU 61 advances the process to S114. Further, in the determination of S108 above, if the laser-off time is not shorter than the time T (S108: NO), the CPU 61 advances the process to S114. Furthermore, in the judgment of S104 above, if the laser-off time has not fallen short of the time T (S104: NO), the CPU 61 advances the process to S114.

In S114, the CPU 61 determines the measurement target. After that, the CPU 61 terminates the measurement target determination process.

Returning to FIG. 3, the CPU 61 performs test printing and laser power measurement (S18). Here, the test printing is performed based on the print data instructed by the user in S100 and stored in the work area of the RAM 62. FIG. Laser power measurement is performed for one or more strokes in one or more characters determined by the measurement target determination process. Specifically, the CPU 61 converts the voltage value output from the power meter 110 while the laser processing apparatus 1 is printing the image determined by the measurement target determination process and digitally converted by the A/D converter 112. Integrate and average over the print time. The value obtained by averaging the integrated voltage value over the printing time is hereinafter referred to as "average laser power".

Next, the CPU 61 determines whether or not the result of the test printing is the desired print density (S20). This determination is made by, for example, visually checking the result of the test printing by the user, and pressing one of the buttons (not shown) of "print density OK", "increase density", and "decrease density" displayed on the liquid crystal display 56. ) can be performed according to the operation from the input operation unit 55 . That is, in this case, the CPU 61 determines that the desired print density is obtained as a result of test printing when the "print density OK" button is operated, and performs test printing when any other button is operated. It is determined that the result is not the desired print density. Note that the determination in S20 may be automatically performed without user operation. Specifically, during test printing, a code such as a bar code or a QR code (registered trademark) is printed along with printing based on the print data. It may be determined whether or not the result of the test printing has the desired print density depending on whether or not decoding is possible. Alternatively, the camera 103 may capture an image of the print based on the print data, and determine whether or not the result of the test printing has the desired print density depending on whether or not the characters of the print result can be recognized from the imaged data. can be

If it is determined in S20 that the result of the test printing does not achieve the desired print density (S20: NO), the CPU 61 changes the current value supplied to the laser oscillator 21 and executes the process of S18 again. Then, the CPU 61 continues the processing of S18 while varying the current value supplied to the laser oscillator 21 until the test printing result reaches the desired print density (S20: YES), the CPU 61 notifies completion of preparation (S22). This notification is made by, for example, displaying completion of preparation on the liquid crystal display 56 . Alternatively, it may be performed by voice. Alternatively, both voice and display may be used. Hereinafter, this situation is the same for notifications. Based on the average laser power calculated in the test printing, the CPU 61 sets, for example, a value of 95% of this average laser power as an appropriate laser power threshold value (lower limit value), for example, the threshold storage area secured in the RAM 62 ( (not shown).

Next, the CPU 61 performs actual printing and laser power measurement (S24). The process of S24 is the same as the process of S18. However, since this is not test printing but actual printing, it is necessary only for test printing, and unnecessary printing, specifically, printing of the above code, is not performed during actual printing.

Next, the CPU 61 compares the average laser power calculated in S24 with the appropriate laser power threshold calculated in S18 and stored in the threshold storage area, and determines that the average laser power is the appropriate laser power threshold. (S26). In this determination, if the average laser power is below the appropriate laser power threshold (S26: YES), the CPU 61 returns the laser power of the laser oscillator 21 to the preset specified value. The amount of current to be supplied is adjusted (S28). After notifying that the automatic adjustment of the current amount has been executed (S30), the CPU 61 advances the process to S32. This notification is made, for example, by displaying on the liquid crystal display 56 that the amount of current supplied to the laser oscillator 21 has been automatically adjusted.

On the other hand, if the average laser power is not below the appropriate laser power threshold in the determination of S26 (S26: NO), the CPU 61 skips S28 and S30 and advances the process to S32.

In S32, the CPU 61 determines whether or not a command to end the main printing has been received. A command to end this printing is sent from the laser processing unit 3 to the print information creation unit 2 when, for example, the production line for the workpiece 7 stops, or when the user makes an emergency stop of the laser processing device 1. be done. In the judgment of S32, if the instruction to end the main printing is not received (S32: NO), the CPU 61 returns the process to S24. On the other hand, when the command to end the main printing is received (S32: YES), the CPU 61 advances the process to S34.

In S34, the CPU 61 notifies the total change amount of the automatically adjusted current amount. This notification is made, for example, by displaying the total change amount of the automatically adjusted current amount on the liquid crystal display 56 . Here, the reason why the total amount of change is notified is to cope with the case where the automatic adjustment of the current amount is performed multiple times.

On the other hand, in the determination of S14, if the fully automatic adjustment mode is not set (S14: NO), the CPU 61 determines whether or not the user selection mode is set (S40 in FIG. 4). In this determination, if the user selection mode is set (S40: YES), the CPU 61 executes the measurement object determination process similar to that of S16 (S42).

Next, the CPU 61 executes test printing with different densities and laser power measurement (S44). In the process of S44, the CPU 61 calculates the average laser power in the same manner as in the process of S18. However, in the process of S44, unlike the process of S18, the user instructs to change the density, and the CPU 61 calculates the average laser power calculated each time the density is changed and the laser oscillator power 21 is associated with the increased or decreased amount of current, displayed on the liquid crystal display 56, for example, and stored in the work area of the RAM 62. FIG.

Next, the CPU 61 selects the desired value and allowable lower limit (for example, the average laser power corresponding to the selected density) selected by the user using the input operation unit 55 from the average laser power for each density displayed on the liquid crystal display 56. 95% value) is accepted (S46). The CPU 61 stores the received desired value and allowable lower limit value in a value storage area (not shown) secured in the RAM 62, for example.

Next, the CPU 61 notifies completion of preparation in the same manner as in S22 above (S48). Then, the CPU 61 performs actual printing and laser power measurement similar to S24 (S50).

Next, the CPU 61 compares the average laser power calculated in S50 with the allowable lower limit value stored in the value storage area, and determines whether the average laser power is below the allowable lower limit value (S52). In this determination, if the average laser power is below the allowable lower limit (S52: YES), the CPU 61 restores the laser power of the laser oscillator 21 to the desired value stored in the value storage area. is adjusted (S54). However, in S54, the amount of current may not be adjusted in certain cases such as when the laser oscillator 21 is driven for a short time. Therefore, the CPU 61 notifies whether or not the automatic adjustment of the amount of current has been executed in subsequent S56. This notification is made, for example, by displaying on the liquid crystal display 56 whether or not the amount of current supplied to the laser oscillator 21 has been automatically adjusted. After executing the process of S56, the CPU 61 advances the process to S58.

On the other hand, in the determination of S52, if the average laser power is not below the allowable lower limit (S52: NO), the CPU 61 skips S54 and S56 and advances the process to S58.

In S58, the CPU 61 determines whether or not a command to end the main printing has been received in the same manner as in S32. In this determination, if the command to end the main printing is not received (S58: NO), the CPU 61 returns the process to S50. On the other hand, when the command to end the main printing is received (S58: YES), the CPU 61 advances the process to S60.

In S60, the CPU 61 notifies the total change amount of the automatically adjusted current amount in the same manner as in S34. After that, the CPU 61 terminates the laser power measurement/adjustment process.

On the other hand, if the user selection mode is not set in the judgment of S40 (S40: NO), the CPU 61 executes the same laser power measurement/adjustment process as in S16 (S70 in FIG. 5). In this case, non-adjustment mode is set.

Next, the CPU 61 performs test printing and laser power measurement in the same manner as in S18 (S72). Then, the CPU 61 backs up the average laser power calculated in S72 as a reference value by storing it, for example, in a reference value storage area (not shown) secured in the RAM 62 (S74).

Next, the CPU 61 notifies completion of preparation in the same manner as in S22 and S48 above (S76). Then, the CPU 61 performs actual printing and laser power measurement in the same manner as in S24 and S50 (S78). Further, the CPU 61 determines whether or not a command to end the main printing has been received (S80) in the same manner as in S32 and S58. In this determination, if the command to end the main printing is not received (S80: NO), the CPU 61 returns the process to S78. On the other hand, when the command to end the main printing is received (S80: YES), the CPU 61 advances the process to S82.

In S82, the CPU 61 compares the reference value backed up in S74 and the average laser power calculated in S78 to determine whether or not the laser power has decreased, and notifies the result of the determination. This notification is made, for example, by displaying on the liquid crystal display 56 whether or not the laser power has decreased. After the process of S82, the CPU 61 ends the laser power measurement/adjustment process.

As described above, the laser processing apparatus 1 of the present embodiment has a laser oscillator 21 that oscillates laser light, an optical system 70 that guides the laser light to an exit port as processed laser light P, and a light receiving section. It is provided with a power meter 110 capable of measuring the output value of laser light based on part of the laser light guided to the light receiving section by the optical system 70 during laser processing, a RAM 62 and a CPU 61 . Then, the CPU 61 calculates an appropriate laser output threshold value based on the laser light output value measured by the power meter 110 during test printing for laser processing, and stores the threshold value in the RAM 62 (S18). Judgment processing for judging whether or not the laser beam output fluctuates based on the output value of the laser beam measured by the power meter 110 and the threshold value stored in the RAM 62 by the threshold setting processing before processing. (S26) and are executed.

As described above, in the laser processing apparatus 1 of the present embodiment, an appropriate laser threshold value can be set in a series of laser processing operations without previously obtaining and inputting or recording a reference value corresponding to a processing target. This can be done without trouble, and it becomes possible to determine whether or not the output of the laser beam from the laser oscillator 21 is fluctuating. Incidentally, in this embodiment, the RAM 62 is an example of "memory". CPU61 is an example of a "control part." The time of test printing is an example of "at first operation timing". The actual printing time is an example of "second operation timing time".

It should be noted that the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

(1) In the above embodiment, the power meter 110 is arranged near the laser oscillator 21 so as to directly receive part of the laser light emitted by the laser oscillator 21. However, the optical system 70 is not limited to this. , or downstream of the galvanometer scanner 18 . With the arrangement of the power meter 110 in the above embodiment, the power meter 110 can purely detect changes in the output of the laser oscillator 21 . On the other hand, in the arrangement of the modified example, not only changes in the output of the laser oscillator 110, but also changes in the diameter of the processing laser beam P, deviation of the optical axis 10, and changes in the mirrors and lenses that make up the optical system 70 and the galvanometer scanner 18. Changes due to contamination and deterioration can also be detected via the power meter 110, and the output can be adjusted in consideration of these as well.

(2) In the above-described embodiment, the reference value T of the jump time is a fixed value in the measurement object determination process of FIG.

(3) In the above embodiment, in S82 of FIG. 5, the presence or absence of a decrease in laser power is notified. can be

(4) In the above embodiment, "at the first operation timing" is set to "at the time of test printing" and "at the second operation timing" is set to "at the time of actual printing", but the present invention is not limited to this. For example, "at the first operation timing" may be "at the time of the first actual printing", and "at the second operation timing" may be "at the time of the second and subsequent actual printing".

(5) In the above embodiment, in the measurement target determination process shown in FIG. 6, the measurement target is selected in units of one stroke of a character, but the present invention is not limited to this. A character or a character string having a long continuous laser irradiation time may be selected for each character. In this case, the process of selecting a selection target is simplified as compared with the above-described embodiment, and the processing time can be shortened. Furthermore, if the print data is an image or a two-dimensional code instead of characters, an area in the image data where the continuous laser irradiation time is long may be selected as the measurement area.

(6) When new print data is input to the print information creation unit 2, a display prompting the user to perform test printing is displayed on the liquid crystal display 56, and when the user performs test printing, The threshold may be updated by measuring the laser output as in the above embodiment.

(7) In the above embodiment, as the judgment processing for judging whether or not the output of the laser light has changed, it is judged whether or not the laser power is below the appropriate threshold value (S26) to determine whether or not the laser power has decreased. However, it is not limited to this. Set not only the lower threshold value of the laser power but also the upper threshold value (for example, a value of 105% of the average laser power during test printing), and check whether the measured laser power exceeds the appropriate upper threshold value of the laser power. It may also be possible to judge whether the laser power is too strong by judging whether the laser power is too strong.

(8) In the above embodiment, the threshold is set and the laser power reduction is determined based on the "average laser power", but the present invention is not limited to this. Instead of the average value, a frequent value or a median value may be calculated to set a threshold value or determine a decrease in laser power.

DESCRIPTION OF SYMBOLS 1... Laser processing apparatus 21... Laser oscillator 55... Input operation part 56... Liquid crystal display 61... CPU 62... RAM 70... Optical system 100... Beam splitter 101... Reflecting mirror 103... Camera 110 ... power meter, 112 ... A/D converter, 120 ... temperature sensor.

Claims (10)

a laser oscillator that oscillates laser light;
an optical system for guiding the laser beam to an exit port as processing laser beam;
a power meter having a light receiving section and capable of measuring an output value of the laser light based on part of the laser light guided to the light receiving section by the optical system during laser processing;
memory;
a control unit;
with
The control unit
a threshold value setting process of calculating an appropriate laser output threshold based on the output value of the laser light measured by the power meter at a first operation timing for laser processing and storing the threshold in the memory;
output fluctuation of the laser light based on the output value of the laser light measured by the power meter at the second operation timing of laser processing and the threshold value stored in the memory by the threshold setting process; a judgment process for judging whether or not it has occurred;
A laser processing device characterized by executing The memory has a print data storage unit that stores print data for printing on an object by laser processing,
The control unit
executing a specific range setting process for setting a specific range from the print data;
In the threshold setting process, the threshold is calculated by averaging output values of the laser light measured by the power meter during laser processing using the print data in the specific range at the first operation timing. death,
In the determination process, based on the threshold value and the average output value of the laser beam measured by the power meter during laser processing using the print data of the specific range at the second operation timing 2. The laser processing apparatus according to claim 1, wherein it is determined whether or not output fluctuation of said laser beam occurs. 3. The laser processing apparatus according to claim 2, wherein, in said specific range setting process, a portion of said print data for which a laser beam irradiation time during laser processing is long is set as said specific range. The print data is data for printing a character string,
4. The laser processing apparatus according to claim 2, wherein in the specific range setting process, the specific range is set for each character of the character string. The time of the first operation timing is the time of test printing before performing the main processing of the laser processing,
5. The laser processing apparatus according to any one of claims 1 to 4, wherein said second operation timing is during main processing of laser processing. The laser processing device further includes
A temperature sensor that measures the temperature of the laser oscillator,
In the threshold setting process, the threshold is set based on the output value of the laser light measured by the power meter when the temperature sensor detects that the laser oscillator is at the saturation temperature at the first operation timing. 6. The laser processing apparatus according to any one of claims 1 to 5, wherein the calculation is performed. The laser processing device further includes
A temperature sensor that measures the temperature of the laser oscillator,
In the determination process, the output value of the laser light is measured by the power meter when the temperature sensor detects that the laser oscillator is at the saturation temperature at the second operation timing. 7. The laser processing apparatus according to any one of claims 1 to 6, wherein it is determined whether or not output fluctuation occurs. The control unit further
2. In the determination process, when it is determined that the output of the laser beam is fluctuating, a notification process is executed to notify a user that there is an abnormality in the laser beam. 8. The laser processing apparatus according to any one of items 1 to 7. The control unit further
In the determination process, when it is determined that the output power of the laser light is fluctuating, the laser oscillator is operated to reduce the difference between the measured output value of the laser light and a predetermined reference value. 9. The laser processing apparatus according to any one of claims 1 to 8, wherein a change process is executed to change the output setting of the laser beam. A laser oscillator that oscillates laser light, an optical system that guides the laser light to an exit port as processing laser light, and a light receiving section, and the laser light guided to the light receiving section by the optical system during laser processing. A laser processing method using a laser processing apparatus comprising a power meter capable of measuring the output value of the laser light based on a part of, a memory, and
a threshold value setting process of calculating an appropriate laser output threshold based on the output value of the laser light measured by the power meter at a first operation timing for laser processing and storing the threshold in the memory;
output fluctuation of the laser light based on the output value of the laser light measured by the power meter at the second operation timing of laser processing and the threshold value stored in the memory by the threshold setting process; a judgment process for judging whether or not it has occurred;
A laser processing method comprising:

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