JP5062838B2 - Laser marking device - Google Patents

Description

  The present invention provides a laser marking device.

  2. Description of the Related Art Conventionally, a marking pattern forming apparatus is known in which an aperture and an fθ lens are provided on a laser beam path from a laser oscillator to a laser beam scanning unit, and the aperture amount of the aperture is controlled according to the line width of the marking pattern. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-244391

However, since the spot diameter of the laser beam converged by the fθ lens changes depending on the position of the fθ lens in the central axis direction, according to the conventional marking pattern forming apparatus, it is intended that the processed surface of the workpiece is not at a specific position. There is a problem that the line width is not reached.
The present invention has been completed based on the above circumstances, and provides a laser marking device capable of processing with a constant processing width regardless of the position of the processing surface of the workpiece in the central axis direction of the converging lens. For the purpose.

1st invention is a laser marking device which forms a character, a symbol, a figure, etc. in a work with a laser beam based on coordinate data, a laser light source which emits the laser beam, and a laser emitted from the laser light source A converging lens for converging light; work information setting means for setting a position of a work surface of the work in the central axis direction of the converging lens; and changing a beam diameter or divergence angle of the laser light incident on the converging lens. A focus position adjusting means for adjusting the focus position of the laser beam, and the focus position adjusting means adjusts the focus position according to the position set by the work information setting means, thereby The processing width which is the width of the point formed when light is irradiated to one point on the work is kept constant.
According to the present invention, processing can be performed with a constant processing width regardless of the position of the processing surface of the workpiece in the central axis direction of the converging lens.

According to a second aspect of the present invention, the focal position adjusting means stores focal position adjustment information for adjusting the focal position to be the processing width for each of a plurality of positions in the central axis direction, and the work information setting means The focal position is adjusted based on the focal position adjustment information corresponding to the position set in (1).
According to this invention, the processing position can be made constant by storing the focus position adjustment information for each position and adjusting the focus position based on the focus position adjustment information corresponding to the set position.

In a third invention, the focal position adjusting means stores the focal position adjustment information for each material of a plurality of types of materials of the workpiece.
According to this invention, even if the workpiece material is different, it can be machined with a constant machining width.

According to a fourth aspect of the present invention, the workpiece information setting means can set the step shape of the machining surface, and the focus position adjusting means has the same machining width at any position on the machining surface. The focal position of the laser beam is adjusted based on the step shape.
According to this invention, even if the processed surface of the workpiece is not flat and has a stepped shape, the same processed width can be obtained at any position on the processed surface.

5th invention is further provided with the coordinate data production | generation means which produces | generates the said coordinate data, The said coordinate data production | generation means is position data which shows the position of the said central-axis direction to each coordinate of the said coordinate data based on the said level | step difference shape. Is added.
According to the present invention, high-speed machining can be performed by adding position data in the central axis direction to each coordinate.

  According to the present invention, processing can be performed with a constant processing width regardless of the position of the processing surface of the workpiece in the central axis direction of the converging lens.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
(1. Overall configuration)
FIG. 1 is a schematic diagram conceptually showing the structure of a laser marking device 1 according to Embodiment 1 of the present invention. The laser marking apparatus 1 employs a so-called galvano scanning method, and includes a laser light source 11, a beam expander 12, a galvano scanner 13, a converging lens 14, a control unit 15, and the like.

  The laser light source 11 (an example of a laser light source) includes a carbon dioxide gas laser that is a gas laser, a YAG laser that is a fixed laser, a semiconductor laser, or a fiber laser, and emits laser light L toward the beam expander 12. The laser light source 11 is configured to be capable of adjusting the laser output, and the laser output is controlled by the control unit 15.

  The beam expander 12 (an example of a focus position adjusting unit) moves a plurality of lenses such as a magnifying lens 12a and a collimator lens 12b, and moves at least one of the plurality of lenses in the optical axis direction of the laser light L (not shown). It consists of a drive motor. The beam expander 12 changes the beam diameter or divergence angle of the laser light L by changing the distance between the magnifying lens 12a and the collimator lens 12b. In the present embodiment, the case where both the beam diameter and the divergence angle are changed will be described as an example. However, only one of the beam diameter and the divergence angle may be changed.

  The galvano scanner 13 includes two galvanometer mirrors that reflect the laser light L, two drive motors that displace the angles of these galvanometer mirrors, and the like. One galvanometer mirror is driven by one drive motor to shift the angle in the vertical direction, and the other galvanometer mirror is driven by the other drive motor to shift the angle in the horizontal direction. As a result, the direction of the laser beam L is changed in two directions, and the irradiation point of the laser beam L moves two-dimensionally on the processing region.

The converging lens 14 is composed of an fθ lens or the like, and converges the laser light L from the galvano scanner 13 to form a laser spot on the workpiece W. A broken line 14 a indicates the direction of the central axis of the converging lens 14.
The control unit 15 (an example of a work information setting unit, a focus position adjustment unit, and a coordinate data generation unit) includes a CPU 15a, a ROM 15b, a RAM 15c, a setting unit 15d, a storage unit 15e, and the like.

The CPU 15a controls each part of the laser marking device 1 by loading various programs stored in the ROM 15b into the RAM 15c and executing them.
The setting unit 15d (an example of a work information setting unit) includes an input device such as a keyboard and a mouse, a display device such as an LCD and a CRT, and the like. For example, the operator selects an operation mode and makes various settings by operating the input device while referring to a screen displayed on the display unit.

  The storage unit 15e (an example of a focus position adjusting unit) is configured by a rewritable nonvolatile memory such as a flash memory or a hard disk, and includes image information representing a print pattern of characters, symbols, figures, and other arbitrary shapes, and convergence. A plurality of tables for associating the position of the lens 14 in the central axis direction and the focus position adjustment information are stored.

(2. Adjustment of focal position by beam expander)
2A, 2B, 3A, and 3B are schematic diagrams for explaining the adjustment of the focal position by the beam expander 12. FIG. 2A and 2B show an example in which the distance between the magnifying lens 12a and the collimator lens 12b is enlarged. When the separation distance is increased, the beam diameter when entering the converging lens 14 is reduced, and the focal length is shortened.

On the other hand, FIG. 3A and FIG. 3B are examples when the separation distance is narrowed. When the separation distance is narrowed, the beam diameter when entering the converging lens 14 is increased, and the focal length is increased. Thus, according to the beam expander 12, the focal position of the convergent lens 14 can be changed by changing the beam diameter and the divergence angle.
When the focal position is adjusted by the beam expander 12, the focal position can be moved without changing the optical path length from the laser light source 11 to the converging lens 14, so that the focal point without increasing the size of the laser marking device 1 can be obtained. The position can be adjusted.

(3. Correspondence between the position of the converging lens in the central axis direction and the focus position adjustment information)
Next, the correspondence between the position of the convergent lens in the central axis direction and the focus position adjustment information will be described.

When a figure is formed on the workpiece with the laser beam L, the position of the workpiece processing surface (hereinafter referred to as “work height”) in the central axis direction of the converging lens 14 is not always constant, and various heights are used. The workpiece is processed.
FIG. 4 is a schematic diagram when processing is performed on workpieces having different heights, and the upper stage shows the processing width when the distance from the converging lens 14 is far (the processing surface of the workpiece is at a low position 16). The lower part shows the change of the machining width when the distance from the converging lens 14 is short (the work surface of the workpiece is at a high position 16 ′).
Here, in this embodiment, the processing width refers to the width of a point formed when a laser beam L is irradiated to one point on the workpiece, the diameter of the point, or a line on the workpiece by moving the laser beam L linearly. It means the line width when forming.
By the way, even if there is a relationship that the focal position should be shifted by B mm to make the line width A μm at a certain height 16, the line width is A μm even if the focal position is shifted by B mm at other heights 16 ′. It will not be. This is because, when the focal position is adjusted by the beam expander 12, the beam angle θ varies depending on the focal position, so that the distance from the focal position varies even with the same spot diameter of A μm.

Therefore, in order to allow a workpiece with any height to be machined with the same machining width, it is necessary to adjust the focal position in consideration of the workpiece height.
Therefore, in the present embodiment, the height of a plurality of workpieces is stored in the storage unit 15e in association with the focus position adjustment information for adjusting the focus position to a constant machining width for each height. Here, the “focus position adjustment information” may be the focus position itself or a control amount of the beam expander 12 for adjusting to the focus position. In the present embodiment, the focus position is described as an example of the focus position adjustment information.

  In the present embodiment, a case will be described as an example where a plurality of processing widths for each height are stored in association with focus position adjustment information for adjusting the processing position to a focus position that is the processing width. In addition, when it may fix to a specific process width, it is not necessary to memorize | store focal position adjustment information for every process width, and what is necessary is just to memorize | store one focus position adjustment information for every height.

  FIG. 5 is a schematic diagram illustrating an example of the tables 21 to 23 in which a plurality of different processing widths are associated with the focal positions. In the present embodiment, these tables 21 to 23 are stored in the storage unit 15e. For example, the first column of the table 21 is a column corresponding to a workpiece height of 180 mm. At this time, if the processing is performed with the focal position coincident with the processing surface (180 mm) of the workpiece, the processing is performed with a line width of 100 μm. According to the table 21, when it is desired to keep the workpiece height as it is and to make the line width 120 μm, it is understood that the focal position should be 185 mm. In this case, the distance to shift the focus is 5 mm.

  For example, the second row is a row corresponding to a workpiece height of 185 mm. At this time, if the processing is performed with the focal position coincident with the processing surface (185 mm) of the workpiece, the processing is performed with a line width of 100 μm. According to the table 21, when it is desired to keep the work height as it is and the line width to be 120 μm, the focal position should be set to 192 mm. In this case, the distance to shift the focus is 7 mm.

  As described above, the line width is changed from 100 μm to 120 μm in each of the two columns, but the distance by which the focal position is shifted is different. For this reason, as described above, in the present embodiment, a plurality of machining widths are stored in association with focal positions for each workpiece height. The correspondence between the machining width and the focal position at a certain height can be obtained by measuring the machining width by performing machining while fixing the workpiece height to the height and changing the focal position.

By the way, the material of the workpiece is not always the same, and printing may be performed on various workpieces of different materials such as metal, resin, glass and the like. If the material is different, the processing width is not necessarily the same even if other conditions are the same.
Therefore, in this embodiment, a table is stored for each material such as metal, resin, and glass.

(4. Setting the step shape of the workpiece)
FIG. 6 is a schematic diagram of a workpiece having a step on the machining surface. The work surface of the workpiece is not necessarily flat and may have a stepped shape with a step as shown in the figure. In this case, if the height of any place on the machining surface is set as the height of the workpiece, the machining width at the other place is different from the intended machining width. Therefore, in this embodiment, the step shape of the processed surface can be set. Here, in the present embodiment, setting means that the operator operates the setting unit 15d to input or change various information. Hereinafter, an example of setting the step shape will be described.

  FIG. 7 is a schematic diagram of a screen 30 for setting the step shape. The screen 30 is a diagram schematically showing on a computer a machining area 32 when viewed from the direction of the laser beam L shown in FIG. 6 and a machining surface 16 of the workpiece W placed in the machining area 32. For example, an operator may operate the mouse or keyboard of the setting unit 15d to diagram the shape of the processing surface 16, or the processing region is imaged from the direction of the laser light L by an image sensor, and the processing surface is processed by image processing. This may be done by extracting the shape.

The coordinate system on the screen 30 corresponds to the coordinate system of the actual machining area. As shown in the figure, a horizontal straight line 33 extending in the X-axis direction and a vertical straight line 34 extending in the Y-axis direction are displayed on the screen 30. The workpiece W in the example shown in the drawing has different machining surface heights on the left and right sides with a line 35 extending in the Y-axis direction as a boundary.
In this case, the operator aligns the vertical straight line 34 with the position of the broken line 35. The workpiece W in the illustrated example has no step extending in the X-axis direction, but when there is a step extending in the X-axis direction, the position of the horizontal straight line 33 is also adjusted. Next, the operator sets the height of the left area and the height of the right area of the vertical straight line 34, respectively. Thus, the step shape of the processed surface is set. The step shape set here is used in a line width control mode to be described later.

  In the above-described example, the steps extending linearly in the X-axis direction and the Y-axis direction have been described as examples. However, the steps extending obliquely with respect to the X-axis and the Y-axis, or curved steps can be set. Also good.

(5. Operation of laser marking device 1)
The laser marking apparatus 1 of the present embodiment has a plurality of operation modes such as a normal operation mode and a line width control mode. Hereinafter, the operation in the normal operation mode and the operation in the line width control mode will be described.

(5.1 Operation in normal operation mode)
The normal operation mode is a mode in which processing is performed without making the processing width constant. In the normal operation mode, the operator performs processing by aligning the position of the processing surface of the workpiece with the focal position guided by the laser marking device 1. The operator does not always need to make the machining width constant. If the machining width does not need to be constant, the worker may perform machining in the normal operation mode.

  The operator operates the setting unit 15d to set a print pattern and gives an instruction for processing. When processing is instructed by the operator, the control unit 15 decomposes the print pattern into line elements based on the image information representing the set print pattern, and outputs a plurality of coordinate data including the start point and end point of those line elements. Generate. This coordinate data is two-dimensional data corresponding to the positional deviation from the irradiation position of the laser beam L when the two galvanometer mirrors are at the rotation center position.

  Next, the control unit 15 provides a drive signal corresponding to the coordinate data to the drive motor and an on / off signal to the laser light source 11. As a result, the X-axis and Y-axis galvanometer mirrors are rotated to move the irradiation point of the laser beam L in the two-dimensional direction on the workpiece, thereby forming the print pattern.

(5.2 Line width control mode operation)
Here, the case where the processed surface has a step shape and the case where there is no step will be described separately.
First, a case where there is no step shape will be described.
FIG. 8 is a flowchart showing a processing flow of the control unit 15 when there is no step shape.
In S100, the operator operates the setting unit 15d to set a print pattern, a workpiece material, a workpiece height, a machining width, and other information necessary for marking. After setting these pieces of information, the operator gives instructions for processing.
In S105, the control unit 15 reads a table corresponding to the set workpiece material from the storage unit 15e, and obtains a focal position associated with the set workpiece height and the set machining width.
In S110, the control unit 15 generates coordinate data based on the image information representing the set print pattern.

  In S115, the control unit 15 controls the beam expander 12 to adjust to the focal position acquired in S105.

  In S120, the control unit 15 forms a print pattern in the same manner as in the normal operation mode.

Next, a case where the processed surface has a step shape will be described.
FIG. 9 is a flowchart illustrating a processing flow of the control unit 15 when there is a step shape.
In S200, the operator operates the setting unit 15d to set a printing pattern, a workpiece material, a step shape, a processing width, and other information necessary for marking. After setting these pieces of information, the operator gives instructions for processing.

In S205, the control unit 15 reads a table corresponding to the set workpiece material from the storage unit 15e, and obtains a focal position associated with the set workpiece height and the set machining width. When there is a step shape, there are a plurality of workpiece heights, so the focal position is acquired for each height.
In S210, the control unit 15 generates coordinate data based on the image information representing the set print pattern.
In S215, the control unit 15 adds data (position data) indicating the height of the point on the processing surface corresponding to the coordinate to each coordinate of the coordinate data based on the set step shape. As a result, three-dimensional coordinate data is generated. If position data indicating the height is added to each coordinate, the height corresponding to each coordinate can be specified in a short time during processing, so that processing can be performed at high speed.

  In S <b> 220, the control unit 15 provides a drive signal corresponding to the coordinate data to the drive motor and an on / off signal to the laser light source 11. As a result, the X-axis and Y-axis galvanometer mirrors are rotated to move the irradiation point of the laser light L in the two-dimensional direction on the workpiece, and the print pattern is printed.

  In the process of S220, the control unit 15 controls the beam expander 12 for each coordinate, and adjusts it to a focal position corresponding to the height specified by the position data added to each coordinate. Thereby, even if the processed surface of the workpiece is not flat and has a stepped shape, the same processed width can be obtained at any position on the processed surface.

Next, the effect of the laser marking device 1 will be described.
FIG. 10 is a schematic diagram for explaining the effect of the laser marking device 1. According to the laser marking apparatus 1, even if there is a relationship that the focal position should be shifted by Bmm to set the line width to A μm for a workpiece of a certain height, the line width is set to A μm for other height workpieces. When doing so, the focal position is shifted by B ′ mm instead of Bmm. Thereby, it can be set as the process width of A micrometer also in the said other height. As described above, according to the laser marking device 1, the beam diameter and divergence angle of the laser light are changed according to the set height, so that the work surface of the workpiece is located at any position in the central axis direction of the converging lens 14. Can be processed with a constant processing width.

  In addition, since the worker only has to set the machining width itself, the work is easy. For example, when it is necessary to set the focal position to be the machining width when machining with a certain machining width, the operator must understand which focal position should be set as the intended machining width. However, it is not necessarily convenient for all workers. On the other hand, if the machining width can be set, it is convenient for many workers.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 11 is a schematic diagram conceptually showing the structure of the laser marking device 2 according to the second embodiment. The configuration of the laser marking device 2 is substantially the same as the configuration of the laser marking device 1 of the first embodiment except that the focal position is adjusted by the converging lens 14 instead of the beam expander 12.

The laser marking device 2 includes a converging lens 14 that is movable, and includes a drive motor (not shown) that moves the converging lens 14 in the direction of its central axis. The control unit 15 moves the convergent lens 14 by controlling the drive motor.
Next, the adjustment of the focal position by the convergent lens 14 will be described.
12 and 13 are schematic diagrams for explaining the adjustment of the focal position by the converging lens 14. FIG. 12 shows an example where the converging lens 14 is moved away from the workpiece W. When the converging lens 14 is moved in a direction away from the workpiece W, the focal position is moved by the same distance in the direction away from the workpiece W as shown in the figure.

  On the other hand, FIG. 13 shows an example when the converging lens 14 is moved in a direction approaching the workpiece W. When it is moved in the direction approaching the workpiece W, the focal position moves by the same distance in the direction approaching the workpiece W as shown in the figure.

  Unlike the case where the focal position is adjusted by the beam expander 12, the beam angle θ does not change when the focal position is adjusted by moving the converging lens 14. Therefore, if a plurality of machining widths are stored in association with the focal position only for a certain reference height (an example of a reference position), the distance based on the distance between the reference height and the set height is used. By correcting the focal position, the focal position corresponding to the set height can be specified, and it is not necessary to store the machining width and the focal position in association with each height of the workpiece W.

Specifically, for example, if a value obtained by subtracting the distance from the convergent lens 14 to the reference position from the distance from the convergent lens 14 to the height of the workpiece W (the position of the workpiece processing surface) is added to the focal position, A focal position corresponding to the height of the workpiece W can be obtained.
As described above, according to the laser marking device 2, since it is only necessary to store a plurality of processing widths in association with the focal position only for the reference position, the amount of work for storing the plurality of processing widths in association with the focal position. Can be reduced.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG.
Since the configuration of the laser marking device according to the third embodiment is substantially the same as the configuration of the laser marking device 1 of the first embodiment, description of the configuration of the laser marking device is omitted here.

  In the laser marking device according to the third embodiment, the initial setting mode can be selected as the operation mode. In the above-described embodiment, the case where the table is stored in advance has been described as an example. However, the processing width stored in the table is discrete, and the target processing width is not necessarily stored. Alternatively, some users may want to print on special metals or multicolor resins. In the initial setting mode, the operator can add a correspondence between a new machining width and a focal position to an existing table, or can add a new table corresponding to a workpiece made of a special material.

  The laser marking device according to the third embodiment is configured such that when the operator operates the setting unit 15d to set the focal position in the initial setting mode, the control unit 15 controls the beam expander 12 to change the focal position. Has been.

Hereinafter, the operation in the initial setting mode will be described with reference to an example of adding a new table.
FIG. 14 is a flowchart of processing for adding a new table.
In S305, the operator operates the setting unit 15d to input a new material name. The control unit 15 stores the input name in the RAM 15c.
In S310, the operator adjusts the machining surface of the workpiece W to a specific position (height), and then operates the setting unit 15d to set the height. The control unit 15 stores the set height in the RAM 15c.
In S315, the operator operates the setting unit 15d to set a specific focus position. The control unit 15 controls the beam expander 12 and adjusts it to the set focal position.
In S320, the operator operates the setting unit 15d to instruct printing. When printing is instructed, the control unit 15 controls each unit to form a printing pattern on the workpiece W. The print pattern to be printed at this time may be a test print pattern prepared in advance.
In S325, the operator measures the line width (processing width) of the printed pattern, and operates the setting unit 15d to input the processing width. The control unit 15 stores the input processing width and the focal position at that time in a new table.
The operator repeats the operations from S315 to S325 while changing the focal position, thereby generating a column corresponding to the height set in S310. And the table corresponding to a new material is produced | generated by changing the height of a workpiece | work and repeating an operation | work further. As a result, a workpiece made of a new material can be machined with the set machining width regardless of the position of the workpiece machining surface in the central axis direction of the converging lens.

<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.
(1) In the above embodiment, the case where the processing width and the focal position (focal position adjustment information) are stored in association with each other has been described as an example. On the other hand, an arithmetic function for automatic control may be obtained from a calculation result using optical simulation software, and a focal position corresponding to the workpiece height and processing width may be obtained by the arithmetic function.
For example, in the above-described tables 21 to 23, if the relationship between the processing width and the focal position can be expressed by an arithmetic function as long as it is a column unit, the arithmetic function may be provided for each column.

  (2) In the above embodiment, the case where the focal position is changed using only one of the beam expander 12 and the converging lens 14 has been described as an example. However, the focal position may be adjusted using both of them.

The schematic diagram of the laser marking apparatus which concerns on one Embodiment of this invention. The schematic diagram of the focus position adjustment means which concerns on one Embodiment of this invention. The schematic diagram of the focus position adjustment means which concerns on one Embodiment of this invention. The schematic diagram of the focus position adjustment means which concerns on one Embodiment of this invention. The schematic diagram of the focus position adjustment means which concerns on one Embodiment of this invention. The schematic diagram of adjustment of the focal position concerning one embodiment of the present invention. The schematic diagram of the table which concerns on one Embodiment of this invention. Schematic diagram of the workpiece. The schematic diagram of the screen which concerns on one Embodiment of this invention. The flowchart which concerns on one Embodiment of this invention. The flowchart which concerns on one Embodiment of this invention. The schematic diagram for demonstrating the effect which concerns on one Embodiment of this invention. The schematic diagram of the laser marking apparatus which concerns on one Embodiment of this invention. The schematic diagram of the focus position adjustment means which concerns on one Embodiment of this invention. The schematic diagram of the focus position adjustment means which concerns on one Embodiment of this invention. The flowchart which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser marking apparatus 2 ... Laser marking apparatus 11 ... Laser light source 12 ... Beam expander (focus position adjustment means)
14: Converging lens (focal position adjusting means)
15 ... Control unit (work information setting means, focus position adjusting means, coordinate data generating means)
15e: Storage unit (focal position adjustment means)
15d ... setting section (work information setting means)
L: Laser light W: Workpiece

Claims (5)

A laser marking device that forms characters, symbols, figures, etc. on a workpiece with laser light based on coordinate data,
A laser light source for emitting the laser light;
A converging lens for converging the laser light emitted from the laser light source;
Workpiece information setting means for setting the position of the processing surface of the workpiece in the central axis direction of the convergent lens;
A focal position adjusting means for adjusting a focal position of the laser light by changing a beam diameter or a spread angle of the laser light incident on the converging lens;
With
The focal position adjusting means adjusts the focal position according to the position set by the work information setting means, thereby processing the width of a point formed when the laser light is irradiated to one point on the work Laser marking device that maintains a constant width.   The focal position adjusting means stores focal position adjustment information for adjusting the focal position to be the processing width for each of a plurality of positions in the central axis direction, and sets the position set by the work information setting means. The laser marking device according to claim 1, wherein the focal position is adjusted based on the corresponding focal position adjustment information.   The laser marking device according to claim 2, wherein the focal position adjustment unit stores the focal position adjustment information for each material of a plurality of types of materials of the workpiece. The workpiece information setting means can set the step shape of the machining surface,
The said focus position adjustment means adjusts a focus position based on the said level | step difference shape so that it may become the same process width in any position on the said process surface. Laser marking device. Coordinate data generating means for generating the coordinate data is further provided,
The laser marking device according to claim 4, wherein the coordinate data generation unit adds position data indicating a position in the central axis direction to each coordinate of the coordinate data based on the step shape.

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