JP4400047B2 - Laser marking method and laser marking apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser marking method and a laser marking apparatus.
[0002]
[Prior art]
There are many inventions relating to laser marking devices that mark a character or a pattern by combining a two-dimensional scanning device and Q-switch pulse train irradiation to improve the accuracy and quality of marking. General laser marking apparatus techniques are described in Japanese Patent Application Laid-Open No. 59-45091 (for example, Patent Document 1) and Japanese Patent Application Laid-Open No. 60-221721. As for suppression of the first pulse peculiar to the Q switch pulse, high frequency power given to the Q switch element in Japanese Patent Application Laid-Open No. Heisei 2-290090 (for example, Patent Document 2) and Japanese Patent Application Laid-Open No. 2001-313434 is a predetermined time constant. A technique is described in which the energy is gradually decreased, the energy accumulated in the laser medium is gradually discharged, and the first pulse is attenuated.
[0003]
A well-known fast pulse suppression method will be described. FIG. 6 shows a clock that is a timing interval for marking, an RF output command signal that instructs the RF circuit that drives the Q switch to output RF, an output signal of the RF circuit, and a laser pulse output that is controlled by the Q switch. A time waveform is shown. When an RF signal is output to the Q switch element, the loss in the laser resonator increases and the laser output is suppressed. After applying RF output for a long time to suppress laser oscillation, if Q-switch pulse oscillation is suddenly started, the energy accumulated in the laser resonator is released, and the peak value is higher than in steady Q-switch oscillation. Appear as a so-called first pulse indicated by a broken line. This causes processing variations. For this reason, the first pulse is suppressed by performing transient control to reduce the RF power applied to the Q switch element so that the laser oscillation is suppressed and the stored energy is gradually released.
[0004]
However, when a laser marking apparatus is configured using a combination of these techniques, there are the following problems.
The first problem is that the laser pulse is not emitted at the line break of the character or figure to be marked, the laser scanner is moved to a new marking start point while maintaining the state, and the laser scanner is moved when the movement is completed. The control sequence of stopping and suppressing the first pulse and starting a new marking after the suppression is performed, and there is a problem that it takes time for marking.
The second problem is that since the device for suppressing the first pulse is configured by hardware, it takes time to optimize the RF output control. The third problem is that the control circuit for suppressing the first pulse is independent, and further, means for synchronizing with laser scanning is required, and the apparatus becomes expensive.
[0005]
[Patent Document 1]
JP 59-45091 A (page 2-3, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 02-290090 (page 2-3, FIG. 4)
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and its purpose is to reduce the time required for laser marking and to make a control method simple by software and a laser embodying the laser marking method. It is to provide a marking device.
[0007]
[Means for Solving the Problems]
A laser marking method according to the present invention is a laser marking method for marking a two-dimensional pattern by scanning an oscillation pulse light of a Q-switch laser oscillator with a laser scanner,
Control of scanning of the oscillation pulse light by the laser scanner according to a scanning pattern composed of a marking pattern to be marked and a free running pattern that needs to be added to the marking pattern in order to scan the marking pattern with a single stroke And
During the period when the marking pattern in the scanning pattern is scanned, the oscillation pulse light is continuously output, and during the period during which the idle pattern is scanned, the output of the oscillation pulse light is stopped, The Q switch for suppressing the first pulse generated in the oscillation pulse light during scanning of the running pattern and immediately before reaching the marking restart position of the marking pattern following the idle running pattern Control the laser oscillator,
Immediately after the scanning position reaches the marking pattern following the idle running pattern, the output of the oscillation pulse light is started to mark the marking pattern.
[0008]
The laser marking apparatus according to the present invention includes a Q-switch laser oscillator, a laser scanner that scans the oscillation pulse light of the Q-switch laser oscillator, an output of the oscillation pulse light of the Q-switch laser oscillator, and a scan of the laser scanner. A laser marking device that performs a two-dimensional pattern marking,
The controller is
In controlling the scanning of the laser scanner, the laser scanner according to a scanning pattern comprising a marking pattern to be marked and a free running pattern that needs to be added to the marking pattern in order to scan the marking pattern with a single stroke Controlling the scanning of the oscillation pulse light by
Upon control of the oscillation pulse light, the period in which scanning the marking pattern in the scan pattern, the oscillation pulse light continuously output, the period in which scanning the sky run pattern, the oscillation pulse light Is stopped while scanning the idle pattern, and during the scanning period immediately before reaching the marking restart position of the marking pattern following the idle pattern, the fast pulse generated in the oscillation pulse light is generated. Control the Q-switched laser oscillator for pulse suppression,
Immediately after the scanning position reaches the marking pattern following the idle running pattern, the output of the oscillation pulse light is started to mark the marking pattern.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a laser marking apparatus that performs marking by two-dimensionally scanning a workpiece with a laser pulse light output from a laser oscillator having a Q switch element and a high frequency power control circuit using a laser scanner. In particular, high-frequency power for controlling the Q switch element in a laser marking device having a function of suppressing the output of a laser pulse having a high peak value called a first pulse generated at the start of laser pulse oscillation and obtaining a uniform laser pulse By controlling the positioning of the laser scanner (hereinafter referred to as RF) and the laser scanner at the same time, the time required for suppressing the first pulse, which has been necessary after the positioning of the conventional laser scanner, is unnecessary, and the marking time is shortened.
[0010]
Embodiments of the present invention will be described with reference to the drawings.
Referring to FIG. 1, there are shown a top view 1A and a side view 1B of the laser marking device of the present invention. The laser marking device of the present invention is configured to perform marking by two-dimensionally scanning a laser beam on a workpiece using a laser scanner, and includes a controller 1, an RF control circuit 2, a laser oscillator 3, The Q switch element 4, the beam expander 5, the laser scanner 6, and the fθ lens 7 are provided, and the workpiece 8 is marked.
The controller 1 controls the Q switch element 4 in the laser oscillator 3 via the laser scanner 6 and the RF control circuit 2. The controller 1 inputs parameters for creating marking data, generates marking data, and controls the laser scanner 6 and the RF control circuit 2 based on the marking data to control marking. The laser oscillator 3 is controlled by the Q switch element 4 controlled by the RF control circuit 2 and emits laser pulse light. The beam expander 5 expands the beam diameter of the laser pulse light output from the laser oscillator 3 toward the laser scanner 6. The laser scanner 6 is a mirror attached to a two-axis drive system so that the laser pulse light emitted from the beam expander 5 passes through the fθ lens 7 and is two-dimensionally scanned on the marking surface of the workpiece 8. The laser pulse light is emitted in a different direction. The fθ lens 7 condenses the laser pulse light whose direction is determined by the laser scanner 6 on the marking surface of the workpiece 8.
[0011]
In FIG. 1, the controller 1 generates data for controlling the suppression of the first pulse in the memory together with distribution data for the laser scanner operation as marking data divided at a predetermined time interval, and the generated data is stored in the memory. Output to the laser scanner 6 and the RF control circuit 2 at the predetermined time interval described above allows the laser scanner and RF output to be controlled simultaneously. Thereby, the suppression of the first pulse can be completed during the positioning of the laser scanner, and marking with no dead time can be performed.
[0012]
Next, the configuration of the marking data generated by the controller 1 will be described with reference to FIG. 2 and FIG. FIG. 2 shows marking data, and FIG. 3 shows an example of a marking pattern.
As shown in FIG. 2, the marking data includes the position (position X and position Y) of the laser scanner at predetermined time intervals in the marking process and RF output instruction data given to the RF control circuit. Here, a predetermined time interval is set as the repetition time of the Q switch pulse. In the RF output instruction data, for example, the data value 50 here indicates instruction data in a state in which a Q-switch laser pulse light having a steady peak value is output. In addition, when the data value is gradually lower than 50, the laser pulse light is not output and the RF output to the Q switch element is gradually reduced so that the first pulse does not appear when the next pulse light output starts. The first pulse suppression instruction to be sent is sent to the RF control circuit, indicating that the same transient control as in the conventional fast pulse suppression method shown in FIG. 6 is being performed.
FIG. 3 shows a case where the letter “A” is marked with a single stroke. Marking from the 10 marking points to 11 and 12 is performed by linking the laser scanner positioning and the continuous oscillation of the Q switch pulse. After the pulse output, the Q switch pulse output is stopped in the section 13 and only the positioning of the laser scanner is controlled. From the marking position 14, the laser scanner positioning and the continuous oscillation of the Q switch pulse are linked to the marking up to 15. It is an example in the case of performing.
The correspondence between the marking process of FIG. 3 and the marking data of FIG. 2 is shown on the right side of the table of FIG. In the marking process as shown in the positioning section 13 of FIG. 3, only the position of the laser scanner is moved without performing laser oscillation, so that the laser oscillation at the next marking position 14 is included in the data portion for moving the laser scanner. The RF output instruction data for suppressing the first pulse that may occur at the time is added, and at the time when the marking position as shown at the laser output start point 14 is reached, the suppression of the first pulse is completed. ing.
In the marking process, if the first pulse suppression process is not completed within the time to move the laser scanner, data for stopping the laser scanner is added until the first pulse suppression process is completed. The
In addition, since the time required for suppressing the first pulse can be predicted in advance, data can be generated so that the suppression of the first pulse is completed simultaneously with the completion of positioning.
[0013]
The operation of the present invention will be described with reference to FIG. 1, FIG. 2, FIG. 4, and FIG.
When marking conditions such as marking characters, graphics, and scanning speed are determined, the controller 1 generates marking data for controlling the RF control circuit 2 and the laser scanner 6 on a built-in memory. After that, when marking is started, an instruction is simultaneously given to the RF control circuit 2 and the laser scanner 6 at predetermined time intervals based on the marking data generated in the controller, and control for marking is performed in an integrated manner. The RF control circuit 2 that has received the RF output instruction signal from the controller 1 immediately outputs power corresponding to the RF output instruction to the Q switch element 4. At the same time, the laser scanner 6 that has received the position data from the controller 1 operates so that the laser is emitted to the position corresponding to the data.
The laser pulse controlled by the Q switch element 4 and emitted from the laser oscillator 3 passes through the beam expander 5, is redirected by the laser scanner 6, passes through the fθ lens 7, and is irradiated onto the workpiece 8, marking Is done. The position of the laser scanner, the RF output instruction value, and the laser pulse output state during the marking process are as shown in FIG. The laser scanner position represents the change in the voltage output of the sensor mounted inside the laser scanner, and the RF output and laser pulse output are respectively the pulse output value and the RF output value from the RF control circuit to the Q switch element. Represents. Regarding the position of the laser scanner, the portion not emitting laser is indicated by a dotted line, and the portion emitting laser is indicated by a solid line.
[0014]
In FIG. 4, the timing time indicated by T <b> 1 is a process of suppressing the first pulse, and is a portion where the laser scanner is moved without performing laser emission, that is, only the positioning of the laser scanner is performed.
On the other hand, FIG. 5 shows the laser scanner position, RF output value, and laser pulse output state in the conventional marking process. In other words, since the conventional method performs the operation of suppressing the first pulse after the positioning is completed, the time spent for the suppression is wasted. This time increases as the number of marking processes increases, and the processing time increases.
[0015]
【The invention's effect】
As described above, according to the laser marking device of the present invention, the following effects can be obtained.
The first effect is that the suppression time of the first pulse that does not contribute to the marking can be deleted or reduced, and the marking time can be shortened. The reason is that processing necessary for suppressing the first pulse can be performed during positioning of the laser scanner.
The second effect is that RF output control for suppressing the first pulse can be easily optimized. This is because the RF output is controlled by software according to the data.
The third effect is that the device can be made inexpensive. This is because the control for suppressing the first pulse and the laser scanning control are performed by one controller.
[0016]
[Brief description of the drawings]
FIG. 1 is a diagram showing the configuration of a laser marking device according to the present invention.
FIG. 2 is a diagram showing marking data generated by a controller of the laser marking apparatus of the present invention.
FIG. 3 is a diagram showing an example of a marking pattern generated by the laser marking device of the present invention.
FIG. 4 is a diagram showing a marking operation of the laser marking device of the present invention.
FIG. 5 is a diagram showing a marking operation of a conventional laser marking device.
FIG. 6 is a diagram showing a time chart of a first pulse suppression method of a Q switch laser.
[Explanation of symbols]
1 Controller 2 RF Control Circuit 3 Laser Oscillator 4 Q Switch Element 5 Beam Expander 6 Laser Scanner 7 fθ Lens 8 Workpiece

Claims (4)

A laser marking method for marking a two-dimensional pattern by scanning an oscillation pulse light of a Q-switch laser oscillator with a laser scanner,
Control of scanning of the oscillation pulse light by the laser scanner according to a scanning pattern composed of a marking pattern to be marked and a free running pattern that needs to be added to the marking pattern in order to scan the marking pattern with a single stroke And
During the period when the marking pattern in the scanning pattern is scanned, the oscillation pulse light is continuously output, and during the period during which the idle pattern is scanned, the output of the oscillation pulse light is stopped, The Q switch for suppressing the first pulse generated in the oscillation pulse light during scanning of the running pattern and immediately before reaching the marking restart position of the marking pattern following the idle running pattern Control the laser oscillator,
The laser marking method, wherein the marking pattern is marked by starting output of the oscillation pulse light immediately after the scanning position reaches the marking pattern following the idle running pattern. When the control of the Q-switch laser oscillator for suppressing the first pulse generated in the oscillation pulse light is not completed within the scanning period of the idle pattern by the laser scanner during the stop of the output of the oscillation pulse light. The scanning of the laser scanner is stopped until the time required for the control elapses, and the output of the oscillation pulse light is started immediately after the scanning of the laser scanner is started after the time required for the control elapses. The laser marking method according to claim 1, wherein: A Q-switch laser oscillator; a laser scanner that scans the oscillation pulse light of the Q-switch laser oscillator; and a controller that controls the output of the oscillation pulse light of the Q-switch laser oscillator and the scanning of the laser scanner. A laser marking device for marking a simple pattern,
The controller is
In controlling the scanning of the laser scanner, the laser scanner according to a scanning pattern comprising a marking pattern to be marked and a free running pattern that needs to be added to the marking pattern in order to scan the marking pattern with a single stroke Controlling the scanning of the oscillation pulse light by
Upon control of the oscillation pulse light, the period in which scanning the marking pattern in the scan pattern, the oscillation pulse light continuously output, the period in which scanning the sky run pattern, the oscillation pulse light Is stopped while scanning the idle pattern, and during the scanning period immediately before reaching the marking restart position of the marking pattern following the idle pattern, the fast pulse generated in the oscillation pulse light is generated. Control the Q-switched laser oscillator for pulse suppression,
The laser marking device, wherein the marking pattern is marked by starting outputting the oscillation pulse light immediately after the scanning position reaches the marking pattern following the idle running pattern. The controller is
When the control of the Q-switch laser oscillator for suppressing the first pulse generated in the oscillation pulse light is not completed within the scanning time of the idle pattern by the laser scanner during the stop of the output of the oscillation pulse light. The scanning of the laser scanner is stopped until the time required for the control elapses, and the output of the oscillation pulse light is started immediately after the scanning of the laser scanner is started after the time required for the control elapses. The laser marking device according to claim 3, wherein

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