WO2013108437A1

WO2013108437A1 - Laser processing device

Info

Publication number: WO2013108437A1
Application number: PCT/JP2012/073932
Authority: WO
Inventors: 直哉山崎; 明久松本; 杉山　徹; 正則熊澤; 康一若子; 井上　浩輔
Original assignee: パナソニックデバイスＳｕｎｘ株式会社
Priority date: 2012-01-20
Filing date: 2012-09-19
Publication date: 2013-07-25
Also published as: JP2013146774A; JP6002392B2

Abstract

In the present invention a control unit changes the scanning speed and changes, as the scanning angle, the range θ0-θ2 of the deflection angle of a Galvano mirror, in accordance with the work distance, so as to enable the printing surface (the processing surface) of a work piece to be processed at the same position and with the same size, regardless of the work distance between a laser emission port (46) and the work piece. In other words, the control unit performs a control such that the range of the deflection angle of the Galvano mirror decreases and the scanning speed decreases as the work distance increases, and the control unit performs a control such that the range of the deflection angle of the Galvano mirror increases and the scanning speed increases as the work distance decreases.

Description

Laser processing equipment

The present invention relates to a laser processing apparatus that scans a laser beam using a galvanometer mirror and irradiates the workpiece with the laser beam.

The laser processing apparatus scans the laser beam with a pair of galvanometer mirrors. The scanned laser light is irradiated on the workpiece so as to have a predetermined spot diameter through a converging lens such as an fθ lens.

By the way, the distance (work distance) between the converging lens and the workpiece may vary depending on the manufacturing variation of the workpiece and the type of the workpiece. In this case, even if the galvano mirror scans the laser beam, the processing range defined by the range of the deflection angle of the scanning mirror changes depending on the work distance. For this reason, a laser beam will be irradiated to a different position.

For example, in the laser processing apparatus of Patent Document 1, the range (scanning angle) of the deflection angle of the galvanometer mirror is changed so that the workpiece is processed at the same position and the same size regardless of the workpiece distance. . According to this configuration, the machining range can be made the same even if the work distance is different. However, it is difficult to keep the processing quality constant only by changing the deflection angle of the galvanometer mirror.

JP 2004-122132 A

An object of the present invention is to provide a laser processing apparatus capable of maintaining the processing quality while maintaining the same processing range even when the work distance is different.

In order to solve the above problems, according to a first aspect of the present invention, a laser emitting unit that emits laser light, a scanning mirror that scans laser light from the laser emitting unit, and a control unit that controls the scanning mirror, There is provided a laser processing apparatus for irradiating a workpiece from a laser emission port with a laser beam from a laser emission unit via a scanning mirror. The control unit narrows the scanning angle of the scanning mirror and increases the scanning angle of the scanning mirror so that the workpiece is processed at the same position and size on the processing surface of the workpiece irrespective of the workpiece distance between the laser emission port and the workpiece. Control is performed so as to reduce the speed, and the smaller the work distance, the wider the scanning angle of the scanning mirror and the higher the scanning speed of the scanning mirror.

According to this configuration, by changing the scanning angle of the galvanometer mirror according to the work distance, the same position and size of the work surface of the work, that is, the work range can be made the same regardless of the work distance. . Furthermore, by changing the scanning speed according to the work distance, the moving speed of the laser beam on the work can be made constant regardless of the change in the scanning angle due to the difference in the work distance. Thereby, even if a work distance changes, the processing quality of a workpiece | work can be maintained, making the processing range the same.

The laser processing apparatus includes a work distance setting unit for setting a work distance, and the control unit can change the scanning angle and the scanning speed of the scanning mirror according to the work distance set by the work distance setting unit. preferable.

According to this configuration, the control unit can change the scanning angle and scanning speed of the scanning mirror according to the work distance set by the setting unit. Therefore, the machining range can be made the same regardless of the work distance set in the setting unit.

In the above laser processing apparatus, it is preferable that the work distance setting unit sets the work distance according to the measurement result from the measuring means for measuring the work distance.

According to this configuration, the setting unit sets the work distance according to the measurement result from the measurement means for measuring the work distance. Therefore, it is possible to save the user from setting the work distance and to set the work distance accurately. Furthermore, the work distance is automatically changed, and the processing range can be made the same more accurately.

In the above laser processing apparatus, it is preferable that the laser machining apparatus further includes an informing means for informing that the work distance set in the work distance setting unit is out of the reference range when the work distance is out of the preset reference range.

According to this configuration, the notification means can notify the user that the work distance set in the work distance setting unit is outside the preset reference range. Therefore, the set work distance is not set outside the reference range.

In the above laser processing apparatus, it is preferable that an invalid means for invalidating the setting of the work distance setting unit is provided when the work distance set in the work distance setting unit is outside a preset reference range.

According to this configuration, when the work distance set in the work distance setting unit is outside the preset reference range, the setting of the work distance setting unit can be invalidated by the invalidating means. Therefore, even if the set work distance is set outside the reference range, machining based on the setting is not started.

The laser processing apparatus includes a processing range setting unit that allows a user to set a processing range, and the control unit controls the processing range set by the processing range setting unit to be the same regardless of the work distance. It is preferable.

According to this configuration, the user can set the processing range through the processing range setting unit. Thus, the control unit controls the machining range set by the machining range setting unit to be the same regardless of the work distance. For this reason, even if the machining range is changed, the workpiece can be machined regardless of the work distance so that the changed machining range is obtained.

The perspective view which shows schematic structure of the laser processing apparatus which concerns on one Embodiment of this invention. The block diagram which shows the outline | summary of a laser processing apparatus. The exploded perspective view of a head part. The perspective view of a connector. Sectional drawing of the protrusion part of a connector. The side view which shows the connection structure of a connector. (A) and (b) are schematic diagrams for explaining laser light converged by an fθ lens. (A) (b) is a schematic diagram for demonstrating the guide display by the 1st and 2nd visible light. (A) is a schematic diagram for demonstrating the scanning of the laser beam by the laser processing apparatus of this invention, (b) is a schematic diagram for demonstrating the scanning of the laser beam by the conventional laser processing apparatus. The schematic diagram which shows the guide mark of another example. (A) (b) is a schematic diagram which shows the guide mark of another example. (A) (b) is a schematic diagram which shows the guide mark of another example. (A) (b) is a schematic diagram which shows the guide mark of another example. The schematic diagram for demonstrating the scanning of the laser beam by the laser processing apparatus of another example. The schematic diagram for demonstrating the scanning of the laser beam by the laser processing apparatus of another example. The schematic diagram for demonstrating the scanning of the laser beam by the laser processing apparatus of another example. (A) is a schematic diagram for explaining scanning of laser light by a laser processing apparatus according to another example, and (b) explains the contents of different processing depending on the number of repetitions of scanning of laser light by the laser processing apparatus. Schematic diagram for (A)-(d) is a schematic diagram for demonstrating the scanning of the laser beam by the laser processing apparatus of another example.

Hereinafter, an embodiment embodying the laser processing apparatus of the present invention will be described with reference to FIGS. 1 to 9A.

As shown in FIG. 1, a laser marking device (laser processing device) 10 includes a main body portion 11, a head portion 14 connected to the main body portion 11 via a fiber cable 12 and an electric cable 13, and an electric power to the main body portion 11. And a console 16 connected via a cable 15.

As shown in FIG. 2, a control unit 17 that controls the operating state of the entire apparatus and a laser oscillation unit (laser oscillator) 18 that oscillates laser light L are accommodated in the main body unit 11. The control unit 17 is electrically connected to the laser oscillation unit 18 and controls driving of the laser oscillation unit 18. The laser light L emitted from the laser oscillation unit 18 is sent to the head unit 14 through the fiber cable 12. One end of the fiber cable 12 is fixed to the head unit 14 via the connector 20. The connector 20 holds the end portion of the fiber cable 12 and is fixed to the rear surface of the housing 30 of the head portion 14.

[connector]
As shown in FIGS. 3, 4, and 6, the connector 20 has a substantially cylindrical holding portion 21. The fiber cable 12 is inserted and held inside the holding portion 21. An extrapolation member 22 is sheathed on the fiber cable 12. The extrapolation member 22 is fixed to the rear end of the holding portion 21. A plate-like flange portion 23 is formed at the end of the holding portion 21. A projecting portion 24 having a cylindrical shape is formed on the front surface of the flange portion 23. The protruding portion 24 is provided coaxially with the holding portion 21 and has a smaller diameter than the holding portion 21. The fiber cable 12 is inserted from the holding portion 21 to the protruding portion 24. The end surface 12a (laser emission surface) of the fiber cable 12 and the end surface 24a of the protrusion 24 are substantially flush. The connector 20 holds the flexible fiber cable 12 straight by a portion extending from the holding portion 21 to the protruding portion 24. A positioning pin 23 a is provided on the surface of the flange portion 23 that faces the head portion 14. A concave portion 25 is provided on the lower surface of the holding portion 21.

As shown in FIG. 5, the projecting portion 24 has three screw holes 24b formed at equal intervals along the circumferential direction. Each screw hole 24b penetrates from the outer peripheral surface of the protrusion 24 to the inner peripheral surface. A locking screw 26 is screwed into each screw hole 24b. The distal end of each rotation-preventing screw 26 slightly protrudes from the inner peripheral surface of the protruding portion 24 and is in contact with the outer peripheral surface of the fiber cable 12 in the protruding portion 24. Thereby, the fiber cable 12 is fixed in the protruding portion 24. For this reason, the rotation of the fiber cable 12 is suppressed in the protrusion 24, and the twist of the fiber cable 12 is suppressed. Further, the locking screw 26 is in contact with the fiber cable 12 at equal intervals along the circumferential direction. For this reason, the fiber cable 12 is fixed with good balance and stability.

As shown in FIG. 3, a contact surface 31 that contacts the flange portion 23 is provided on the rear surface of the housing 30. The connector 20 is fixed to the contact surface 31 with a plurality of screws 20a. The contact surface 31 has an annular shape extending along the outer edge of the flange portion 23. On the inner side of the contact surface 31, an accommodation recess 32 into which the protrusion 24 is inserted is provided. A gap is provided in the axial direction (optical axis direction) and the radial direction between the wall constituting the housing recess 32 and the protruding portion 24. A disc-shaped protective glass 33 is provided in the inner portion 32 a of the housing recess 32. The housing recess 32 and the interior of the housing 30 are partitioned by the protective glass 33. In the housing recess 32, the protective glass 33 and the end surface 24a of the protrusion 24 are opposed to each other while being close to each other. A gap is provided between the wall of the housing recess 32 and the rotation-preventing screw 26 so that they do not interfere with each other.

Two positioning holes 34 into which the positioning pins 23 a of the connector 20 are inserted are formed in the contact surface 31 of the housing 30. The positioning hole 34 shown on the left side of FIG. 3 is a long hole. For this reason, movement of the positioning pin 23 a is allowed in the positioning hole 34. Each positioning pin 23a and each positioning hole 34 constitute positioning means for positioning the connector 20 and the head portion 14 in a direction orthogonal to the optical axis of the laser light L.

A sealing member (not shown) is interposed between the flange portion 23 and the contact surface 31. Thereby, the gap between the flange portion 23 and the contact surface 31 is sealed, and entry of water or the like into the housing recess 32 is suppressed. In the connector 20, the place where the rotation-preventing screw 26 and the screw hole 24b are provided is a place where it is desired to avoid adhesion of water or the like. Therefore, according to this embodiment, the protrusion 24 is disposed in the housing recess 32 in which the watertightness is maintained, and the rotation screw 26 and the screw hole 24 b are provided in the protrusion 24. This eliminates the need to provide a seal structure for avoiding adhesion of water or the like to the rotation stop screw 26 and the screw hole 24 b separately from the seal structure between the connector 20 and the housing 30. For this reason, the structure of the whole apparatus is simplified. Further, since the protruding portion 24 enters the receiving recess 32, the length of the connector 20 protruding from the housing 30 is suppressed while securing the length of the connector 20 necessary to keep the fiber cable 12 straight. Yes.

In the housing 30, a connection terminal portion 35 to which the electric cable 13 is attached and detached is provided above the contact surface 31. A rectangular parallelepiped convex portion 36 protruding toward the connector 20 is provided below the contact surface 31. The convex portion 36 is fitted into the concave portion 25 of the connector 20. The convex portion 36 and the concave portion 25 function as positioning and a guide when the connector 20 is assembled to the housing 30.

[Head]
As shown in FIG. 2, in the housing 30, a half mirror 41 as a light merging means is provided at the subsequent stage of the protective glass 33. The half mirror 41 is disposed on the optical axis of the laser light L emitted from the fiber cable 12 and incident from the protective glass 33. The half mirror 41 transmits a predetermined ratio of the laser light L.

A pair of galvanometer mirrors 42 is disposed behind the half mirror 41 on the optical axis of the laser beam L. The pair of galvanometer mirrors 42 are scanning mirrors that reflect the laser beam L toward the workpiece W and scan the laser beam L. Each galvanometer mirror 42 is rotated by a galvano motor 43. As each galvanometer mirror 42 rotates, the laser light L irradiated onto the workpiece W is scanned in the XY direction (two-dimensional direction). Further, when the galvano motor 43 is driven by the control unit 17, the angle of each galvano mirror 42 is controlled.

Below the galvanometer mirror 42, an fθ lens (convergence lens) 44 is arranged. The fθ lens 44 converges the laser beam L reflected by the galvanometer mirror 42 until a predetermined spot diameter is obtained on the print surface Wa of the workpiece W. Thus, the energy density of the laser light L is increased to an energy density suitable for marking.

A laser emission port 46 partitioned by a protective glass 45 is formed below the fθ lens 44. The laser beam L converged by the fθ lens 44 is irradiated on the print surface Wa of the workpiece W through the protective glass 45. The laser beam L is scanned in a two-dimensional direction on the printing surface Wa. With such an operation, characters, figures, and the like are marked on the print surface Wa of the workpiece W. In this embodiment, each galvanometer mirror 42 and the fθ lens 44 constitute an irradiation optical system that irradiates the workpiece W with the laser light L emitted from the end surface 12a of the fiber cable 12.

In the housing 30, a first visible light source 51 disposed in the vicinity of the half mirror 41 and a second visible light source 52 disposed in the vicinity of the lower portion of the housing 30 are provided. The visible light VL1 emitted from the first visible light source 51 is reflected by the half mirror 41 toward the galvanometer mirror 42. Then, the visible light VL <b> 1 reflected by the galvanometer mirror 42 is irradiated onto the print surface Wa of the workpiece W through the fθ lens 44. Here, the galvanometer mirror 42 scans the visible light VL1 in the two-dimensional direction in the same manner as when scanning the laser light L. A guide mark Ga as shown in FIG. 8B is displayed by the visible light VL1 scanned by the galvanometer mirror 42 in this way. The guide mark Ga is displayed as a circle figure centered on the cross and the intersection of the cross. The cross point of the guide mark Ga indicates the origin (center) of the XY coordinates in the scanning of the galvano mirror 42 and is located on the axis of the fθ lens 44.

The second visible light source 52 is disposed between the fθ lens 44 and the connector 20. The second visible light source 52 emits the second visible light VL2 toward the print surface Wa of the workpiece W. The second visible light VL2 is emitted obliquely with respect to the first visible light VL1. The optical axis of the second visible light VL2 intersects with the axis of the fθ lens 44. On the printing surface Wa of the workpiece W, one guide point is displayed by the second visible light VL2. FIG. 8B shows guide points Gb0, Gb1, and Gb2 as examples of guide points. The second visible light VL2 is green, and the first visible light VL1 is red.

The connection terminal portion 35 is electrically connected to the galvano motor 43, the first visible light source 51, and the second visible light source 52. Accordingly, the control unit 17 is electrically connected to the galvano motor 43, the first visible light source 51, and the second visible light source 52 via the electric cable 13 and the connection terminal unit 35.

A console 16 having a display unit 16a and an operation unit 16b is connected to the main body unit 11. The user operates the operation unit 16b to set desired print data. The print data set by the operation unit 16 b is output to the control unit 17 of the main body unit 11 through the electric cable 15. The control unit 17 controls the laser oscillation unit 18, the galvano motor 43, the first visible light source 51, and the second visible light source 52 based on the print data.

[Laser marking]
Next, marking on the workpiece W by the laser marking device 10 will be described.

The control unit 17 drives the laser oscillation unit 18 and the galvano motor 43 based on the print data. The laser oscillating unit 18 emits laser light L to the fiber cable 12, and the laser light L is transmitted to the head unit 14 via the fiber cable 12. The laser light L emitted from the end surface 12 a of the fiber cable 12 passes through the half mirror 41 and is then irradiated onto the print surface Wa of the workpiece W through the fθ lens 44 and the protective glass 45. The laser beam L is scanned in a two-dimensional direction on the print surface Wa by the galvanometer mirror 42.

The laser light L emitted from the fiber cable 12 is emitted as parallel light (that is, the divergence angle is approximately 0 degrees), and specifically, is made into parallel light by a collimator lens or the like. As shown in FIG. 7A, the laser beam L that is parallel light is incident on the fθ lens 44. Incident light that is laser light L incident on the fθ lens 44 is converged with a predetermined refractive index based on the performance of the fθ lens 44. FIG. 7B shows the diameter (spot diameter Sr) of the laser light L at the focal position P0 of the fθ lens 44, and the spot diameter Sr is obtained by the following equation.

As can be seen from this equation, the smaller the incident light diameter Lw, the larger the spot diameter Sr of the laser light L. When the spread angle of incident light is a constant value, the focal depth df shown in FIG. 7A becomes deeper as the spot diameter Sr is larger. That is, the smaller the diameter Lw of the incident light, the deeper the focal depth df of the laser light L.

Usually, the diameter of the incident light is determined so as to obtain a spot diameter designed at the focal point (aperture position). However, in the present embodiment, the diameter Lw of the incident light is made smaller than the designed diameter of the incident light in order to make the spot diameter of the laser light L larger than its design value and deepen the focal depth df. . By doing in this way, the workpiece | work W can be irradiated with the laser beam L with the deep focal depth df. In the range of the focal depth df thus obtained, the energy of the laser light L is substantially uniform and large enough to ensure the desired marking quality, and the diameter (spot diameter Sr) of the laser light L is also substantially uniform. . For this reason, the desired marking on the printing surface Wa becomes possible by matching the printing surface Wa of the workpiece W within the range of the focal depth df. Further, as long as the position of the print surface Wa of the workpiece W is within the range of the focal depth df, the quality of the marking becomes substantially uniform.

In the conventional laser marking device, the diameter of the incident light incident on the fθ lens 44 is larger than that of the present embodiment in order to secure desired energy at the focal point. FIGS. 7A and 7B show an example of the laser beam La in a conventional laser marking apparatus by a two-dot chain line. In the conventional laser marking apparatus, since the diameter of incident light is large, the spot diameter at the focal point is small and the focal depth is shallow. For this reason, although high energy can be obtained at the focal point, the depth of focus is shallow, so that it is necessary to closely adjust the work distance corresponding to the distance from the laser emission port 46 to the print surface Wa of the work W and the focus of the laser light. . For this reason, the aperture position in the Z-axis direction corresponding to the axial direction of the fθ lens 44 is adjusted by changing the divergence angle of incident light using a variable lens distance beam expander, a 3D scanner, or the like. In this way, it was possible to cope with marking on the printing surface of various types of workpieces having different work distances or workpieces having inclined surfaces, steps, or irregularities.

On the other hand, the laser marking device 10 of the present embodiment does not include an inter-lens distance variable beam expander or a 3D scanner that changes the spread angle of the laser light L, and the laser light L emitted from the fiber cable 12 is The light enters the fθ lens 44 with the diameter Lw kept small. Thereby, the focal depth df becomes deep. As the focal depth df increases, the range that can be regarded as a focal point (distance in the Z-axis direction) increases. For this reason, even in a configuration in which the focal point of the laser beam L is fixed, that is, a configuration in which the inter-lens distance variable beam expander, the 3D scanner, and the like are omitted, there are various workpieces, slopes, steps, and irregularities with different work distances. Marking on the printing surface of the workpiece is possible.

Also, there is a case where the laser beam L is applied to perform oxidation printing (black marking) on the workpiece W mainly made of a metal material such as a bearing or a carbide drill. In this case, the spot diameter of the laser beam L on the printing surface Wa needs to satisfy certain conditions. Moreover, it is preferable that the oscillation method of the laser oscillation part 18 is continuous (CW: Continuous wave) oscillation. This is because, in thermal processing, the physical properties of the workpiece W are more likely to change when the laser beam L is oscillated on the average than when the laser beam L is oscillated instantaneously with high energy (pulse oscillation). It is. When the range of the focal depth df is increased as in the present embodiment, the diameter Lw of the fθ lens 44 is set so as to satisfy the above-described certain condition in order to oxidize and print on the workpiece W.

In the conventional marking device, the print surface Wa of the workpiece W is set at a position offset from the actual focus position by adjusting the focus position so as to satisfy the above-described certain condition. Then, the position of the focal length needs to be offset by using a variable inter-lens distance beam expander or a 3D scanner following the change of the position of the printing surface Wa, that is, the work distance. However, according to the conventional configuration, when the work distance changes, the divergence angle is changed by an inter-lens distance variable beam expander, a 3D scanner, or the like. For this reason, since the condition of the spread angle is different at the offset position as described above, the print quality may be affected if the work distance changes. In that respect, according to the laser marking device 10 of the present embodiment, the diameter of the incident light incident on the fθ lens 44 is reduced and the range of the focal depth df is increased, so that printing is performed within the focal depth df. Quality can be the same.

[Guide Display]
In the present embodiment, before laser marking with the laser beam L, guide display on the print surface Wa by the first and second visible lights VL1 and VL2 is possible. For example, based on a predetermined guide display operation at the operation unit 16b, the control unit 17 causes the first and second visible light sources VL1 and VL2 to be emitted from the first and second

visible light sources

51 and 52, respectively. Then, on the printing surface Wa of the workpiece W, the guide mark Ga is displayed by the first visible light VL1, and the guide point is displayed by the second visible light VL2.

The guide mark Ga is displayed by the first visible light VL1 scanned by the galvano mirror 42. For this reason, the size of the guide mark Ga slightly changes depending on the position of the print surface Wa in the Z-axis direction (Z-axis position). However, since the change in the size of the guide mark Ga is so small that it can be ignored, the size of the guide mark Ga will not be changed depending on the Z-axis position of the printing surface Wa.

On the other hand, as shown in FIGS. 8A and 8B, the display position of the guide point by the second visible light VL2 changes with respect to the guide mark Ga depending on the position of the print surface Wa in the Z-axis direction. FIG. 8B shows the locus T of the guide point with a broken line when the Z-axis position of the printing surface Wa is changed. The trajectory T is a straight line.

When the print surface Wa is at the focal position P0 (reference position) of the fθ lens 44, the guide point Gb0 displayed on the print surface Wa overlaps the center (cross point of the cross) of the guide mark Ga. The focal position P0 coincides with the center position of the focal depth df in the Z-axis direction. That is, when the guide point displayed on the print surface Wa overlaps the cross point of the guide mark Ga, the print surface Wa is positioned at the center of the focal depth df (see FIG. 7A).

The diameter of the guide mark Ga circle is set to correspond to the range of the focal depth df. That is, when the printing surface Wa is at the lower limit position P1 of the focal depth df, the guide point Gb1 is displayed on the circle line of the guide mark Ga, and when the printing surface Wa is at the upper limit position P2 of the focal depth df, the guide mark Ga. A guide point Gb2 is displayed on the circle line. The display positions of the guide point Gb1 and the guide point Gb2 are symmetric with respect to the center of the guide mark Ga.

In the range of the focal depth df (range from the lower limit position P1 to the upper limit position P2), it is possible to mark the printing surface Wa of the workpiece W with substantially uniform quality. For this reason, when the guide point is displayed inside the circle of the guide mark Ga, the Z-axis position of the printing surface Wa is within the range of the focal depth df, and marking on the printing surface Wa is possible. On the other hand, when the guide point is displayed outside the circle of the guide mark Ga, the Z-axis position of the printing surface Wa is outside the range of the focal depth df, and the Z-axis position of the printing surface Wa needs to be adjusted. Thereby, the user can confirm before marking whether the printing surface Wa is in the Z-axis position where marking can be performed by viewing the positional relationship between the guide mark Ga and the guide point displayed on the printing surface Wa. .

[Print range adjustment]
The control unit 17 controls the galvanometer mirror 42 so that the printing range (marking range) does not change according to the work distance. The user can input and change the work distance via the operation unit 16b as a setting unit. In the laser marking device 10, the work distance reference position is set in advance by the manufacturer. In the present embodiment, as shown in FIG. 9A, the reference position is a position Wd0. Further, the speed of the laser beam L at the reference position Wd0 is set by the operation unit 16b.

Here, as shown in FIGS. 9A and 9B, when the printing surface Wa is at the reference position Wd0, the range of the deflection angle, which is the scanning angle of the galvanometer mirror 42 necessary for scanning the printing range Ar0, is defined as the range. Let θ0. When the work distance is large and the printing surface Wa is at a position Wd1 far from the reference position Wd0, the printing range is wide if the sway angle range θ0 of the galvanometer mirror 42 remains as indicated by Ar1 in FIG. 9B. Become. Therefore, as shown in FIG. 9A, the range of the swing angle of the galvanometer mirror 42 is set to the range of the swing angle θ1 that is narrower than the range of the swing angle θ0. Thereby, it is possible to scan a printing range substantially equivalent to the printing range Ar0. At this time, the swing angle range θ1 of the galvanometer mirror 42, that is, the drive range of the galvanometer mirror 42 is narrowed. For this reason, the control unit 17 controls the galvano motor 43 so as to slow down the drive range (scanning speed) of the galvano mirror 42 per unit distance in the deflection angle range θ1. Thereby, the moving speed of the laser beam L on the workpiece W becomes constant.

On the other hand, when the work distance is small and the print surface Wa of the work W is at a position Wd2 that is closer to the reference position Wd0, as shown by Ar2 in FIG. The range becomes narrower. Therefore, as shown in FIG. 9A, the range of the swing angle of the galvanometer mirror 42 is set to a range of the swing angle θ2 that is wider than the range of the swing angle θ0. Thereby, it is possible to scan a printing range substantially equivalent to the printing range Ar0. At this time, the swing angle range θ2 of the galvanometer mirror 42, that is, the drive range of the galvanometer mirror 42 is expanded. For this reason, the control unit 17 controls the galvano motor 43 so as to increase the scanning speed of the galvano mirror 42 in the deflection angle range θ1. Thereby, the moving speed of the laser beam L on the workpiece W becomes constant.

Next, the characteristic effects of this embodiment will be described.

(1) The control unit 17 changes the scanning angle and scanning speed of the galvanometer mirror 42 according to the work distance. As a result, regardless of the distance of the workpiece distance between the laser emission port 46 and the workpiece W, the printing surface Wa (processing surface) of the workpiece W is processed at the same position and size. That is, as the work distance increases, the control unit 17 narrows the range of the swing angle as the scanning angle of the galvanometer mirror 42 and decreases the scanning speed of the galvanometer mirror 42. Further, as the work distance is smaller, the control unit 17 widens the range of the deflection angle as the scanning angle of the galvanometer mirror 42 and increases the scanning speed of the galvanometer mirror 42. Further, the control unit 17 changes the deflection angles θ0 to θ2 as the scanning angles of the galvanometer mirror 42 according to the work distance. As a result, regardless of the work distance, the printing surface Wa of the workpiece W can be processed in the same position and size, that is, in the same printing range as the processing range Ar0. Furthermore, by changing the scanning speed according to the work distance, the moving speed of the laser light L on the work W can be made constant regardless of the change in the scanning angle due to the difference in the work distance. Thereby, even if the workpiece distance is changed, the machining quality of the workpiece W can be maintained while keeping the machining range Ar0 the same.

Further, by increasing the range of the focal depth df of the laser light L, printing can be performed on the printing surface Wa with the same quality even if the work distance changes within the range of the focal depth df. Further, it is not necessary to adjust the divergence angle as in the case of the inter-lens distance variable beam expander or 3D scanner. For this reason, an inter-lens distance variable beam expander, a 3D scanner, or the like is not necessary, and the number of parts in the entire apparatus can be suppressed, which can contribute to cost reduction.

(2) The control unit 17 changes the scanning angle (deflection angle) and scanning speed of the galvano mirror 42 according to the work distance set by the operation unit 16b. In this case, the scanning angle and scanning speed of the galvanometer mirror 42 can be changed without using a sensor or the like that detects the work distance. In addition, the machining range can be made the same regardless of the set work distance.

(3) The laser marking device 10 includes teaching means including a first visible light source 51 and a second visible light source 52. The first visible light source 51 irradiates the printing surface Wa with the first visible light VL1. The second visible light source 52 emits the second visible light VL2 obliquely with respect to the axis of the fθ lens 44 so that the second visible light VL2 intersects the first visible light VL1. By irradiating the printing surface Wa with the first visible light VL1, a guide mark Ga indicating a range corresponding to the focal depth df of the laser light L is displayed on the printing surface Wa. The irradiation position (guide point display position) of the second visible light VL2 changes in a direction (XY axis direction) orthogonal to the Z axis direction according to the position of the print surface Wa in the Z axis direction. Then, the display position of the guide point with respect to the guide mark Ga teaches whether or not the print surface Wa is at a position that can be processed. For this reason, the user simply irradiates the print surface Wa with the first and second visible lights VL1 and VL2 before laser marking, and confirms whether there is a guide point within the range of the guide mark Ga. It is possible to easily grasp whether or not laser marking is possible on the printing surface Wa.

(4) When the printing surface Wa is within the range of the focal depth df, the guide point is within the range of the guide mark Ga, and when the printing surface Wa is outside the range of the focal depth df, the guide point is at the guide mark Ga. It is out of range. That is, whether or not the print surface Wa of the workpiece W is at a position that can be processed can be taught by whether or not the guide point is within the range of the guide mark Ga.

(5) The guide mark Ga is shown as an annular frame (circle) indicating a range corresponding to the focal depth df. That is, whether or not the print surface Wa of the workpiece W is at a position where it can be processed is taught by whether or not the guide point display position is within the frame (circle) of the guide mark Ga. For this reason, the user can intuitively grasp whether or not laser marking is possible on the printing surface Wa.

(6) The guide mark Ga includes a cross-shaped figure (focus position teaching mark). In a state where the printing surface Wa is at the focal position P0 (center of the focal depth df) of the fθ lens 44, the display position of the guide point overlaps with the cross point of the guide mark Ga. That is, the user can grasp whether or not the print surface Wa is at the focal position P0 of the fθ lens 44 based on whether or not the guide point overlaps the intersection of the guide marks Ga.

(7) The second visible light VL2 is green visible light, and the first visible light VL1 is red visible light. That is, since the color of the first visible light VL1 and the color of the second visible light VL2 are different, the visibility of the guide mark Ga and the guide point is improved. As a result, the user can more easily grasp whether or not laser processing on the printing surface Wa is possible.

(8) The connector 20 is provided with a cylindrical protrusion 24 through which the fiber cable 12 is inserted. The protrusion 24 is inserted into the housing recess 32 of the housing 30. By sealing the gap between the connector 20 and the housing 30, the water tightness in the housing recess 32 is ensured. Further, the protruding portion 24 is formed with a screw hole 24b penetrating from the outer peripheral surface to the inner peripheral surface. A locking screw 26 that contacts the fiber cable 12 inserted through the protruding portion 24 is screwed into the screw hole 24b. According to this configuration, the twisting of the fiber cable 12 can be suppressed by the anti-rotation screw 26. Further, it is not necessary to provide a seal structure for avoiding adhesion of water or the like to the rotation-preventing screw 26 and the screw hole 24 b separately from the seal structure between the connector 20 and the housing 30. For this reason, the structure of the whole apparatus is simplified. Furthermore, since the protruding portion 24 enters the receiving recess 32, the entire length of the connector 20 necessary to keep the fiber cable 12 straight can be secured. Further, the length of the connector 20 protruding from the housing 30 can be suppressed. Therefore, the total length of the head portion 14 including the connector 20, that is, the total length in the assembly direction of the connector 20 can be kept small.

(9) The detent screws 26 are provided at equal intervals along the circumferential direction of the fiber cable 12. For this reason, since the fiber cable 12 can be fixed with good balance, the fiber cable 12 can be fixed stably.

In addition, you may change the embodiment of this invention as follows.

In the above embodiment, the user directly inputs the work distance by operating the operation unit 16b. However, the user inputs the distance between the fθ lens 44 and the mounting surface of the work W and the height of the work W, and the work distance. May be calculated by the control unit 17. Further, the laser marking device 10 may be provided with a sensor as a measuring means for measuring the work distance. In this case, the scanning angle and scanning speed of the galvanometer mirror 42 can be accurately changed based on the measurement result from the sensor. Furthermore, the work distance is automatically changed, so that the machining range can be made more accurate.

In the above embodiment, when the work distance set by the operation unit 16b is outside the preset reference range, a notification unit for notifying that effect may be used.

In the above embodiment, the control unit 17 may control the setting of the work distance setting unit to be invalidated when the work distance set in the work distance setting unit is outside the preset reference range. Good.

In the above embodiment, the control unit 17 controls the print range to be the print range Ar0 regardless of the work distance, but the print range Ar0 can be arbitrarily changed using the operation unit 16b as the processing range setting unit. Also good. In this case, the control unit 17 controls the scanning angle and the scanning speed based on the work distance so that the printing range set by the operation unit 16b is the same regardless of the work distance. In this case, the user can set and change the processing range. Even if the machining range is changed, the workpiece can be machined regardless of the work distance so that the changed machining range is obtained.

In the above embodiment, the size of the range indicated by the guide mark Ga may be adjustable. For example, when higher accuracy is required by higher marking quality, that is, by the magnitude of the laser power, the range (depth of focus) that can be regarded as the focal point of the laser light L becomes narrower. On the other hand, when high marking quality is not required, that is, when the accuracy of the laser power is not so high, the range that can be regarded as the focal point of the laser light L is widened. That is, the convenience of the guide mark Ga is improved by making the size of the guide mark Ga adjustable according to the marking mode. The user operates the operation unit 16b to input a necessary laser power value and material of the workpiece W. The control unit 17 controls the size of the guide mark Ga by drive control of the galvanometer mirror 42 based on the user input. Further, the user may be able to directly set the size of the guide mark Ga by operating the operation unit 16b. According to this configuration, it is possible to easily grasp whether or not highly accurate laser marking is possible when the range of the guide mark Ga is adjusted to be small.

In the above embodiment, the first visible light VL1 is red visible light and the second visible light VL2 is green visible light. However, the present invention is not limited to this. The colors of the first visible light VL1 and the second visible light VL2 may be changeable. In this case, the operation unit 16b may be operated to set the colors of the first visible light VL1 and the second visible light VL2. Further, the operation unit 16b is operated to input the color of the workpiece W, and the first and second visible lights VL1 and VL2 having colors (for example, complementary colors) having good visibility with respect to the color of the workpiece W are emitted. Also good. According to this configuration, since the colors of the first and second visible lights VL1 and VL2 can be set according to the color of the workpiece W, the visibility of the guide mark Ga and the guide point is further improved.

In the above embodiment, the second visible light source 52 is disposed between the fθ lens 44 and the connector 20, but the second visible light VL2 from the second visible light source 52 intersects the axis of the fθ lens 44. And as long as it irradiates the printing surface Wa, you may arrange | position in arbitrary positions.

In the above embodiment, the guide mark Ga has a shape made up of a cross and a circle centered on the intersection of the cross, but the cross may be omitted and only the circle may be used. For example, the figure may include a lower limit position teaching line Gd and an upper limit position teaching line Gu as shown in FIG. The lower limit position teaching line Gd and the upper limit position teaching line Gu are dividing lines positioned on the guide point trajectory T, and correspond to the lower limit position P1 and the upper limit position P2 of the focal depth df, respectively. That is, when the print surface Wa is at the lower limit position P1 of the focal depth df, the guide point Gb1 is displayed on the lower limit position teaching line Gd. On the other hand, when the print surface Wa is at the upper limit position P2 of the focal depth df, the guide point Gb2 is displayed on the upper limit position teaching line Gu. According to this configuration, whether or not the printing surface Wa is at the Z-axis position where marking can be performed is taught depending on whether or not the guide point is located between the lower limit position teaching line Gd and the upper limit position teaching line Gu. . For this reason, the user can intuitively grasp whether or not laser marking is possible on the printing surface Wa. In addition to the guide marks shown in FIG. 10, for example, a cross similar to the guide mark Ga may be provided between the lower limit position teaching line Gd and the upper limit position teaching line Gu.

In the above embodiment, the change in the size of the guide mark Ga with respect to the Z-axis position of the printing surface Wa is negligibly small. However, the guide mark in other cases is shown in FIGS. 11 (a) to 13 (b). It explains according to. As the work distance increases, the size of the guide mark increases.

The guide mark Ga1 shown in FIGS. 11A and 11B includes a first arc K1 (lower limit position teaching line) and a second arc K2 (upper limit position teaching line). The diameter of the first arc K1 is smaller than the diameter of the second arc K2. The first arc K1 and the second arc K2 correspond to the lower limit position P1 and the upper limit position P2 of the focal depth df, respectively. When the print surface Wa is at the upper limit position P2 of the focal depth df, the guide point Gb2 is displayed on the second arc K2, as shown in FIG. On the other hand, when the print surface Wa is at the lower limit position P1 of the focal depth df, the work distance is larger than that of the upper limit position P2, so that the size of the guide mark Ga1 is increased as shown in FIG. At this time, the guide point Gb1 is displayed on the first arc K1. That is, whether or not the printing surface Wa is at the Z-axis position where marking can be performed is taught by whether or not the guide point is located between the first arc K1 and the second arc K2. In this way, by making the diameters of the first arc K1 and the second arc K2 different, it is possible to cope with the case where the size of the guide mark Ga1 changes depending on the Z-axis position of the printing surface Wa.

Further, the guide mark Ga2 shown in FIGS. 12A and 12B is composed of an ellipse and a cross-shaped figure within the ellipse. The major axis of the ellipse of the guide mark Ga2 extends along the trajectory T direction of the guide point, and both ends of the ellipse in the major axis direction correspond to the upper limit position P2 and the lower limit position P1 of the focal depth df of the laser beam L, respectively. is doing. When the print surface Wa is at the upper limit position P2 of the focal depth df, as shown in FIG. 12A, the guide point Gb2 is displayed on the first end portion in the major axis direction of the ellipse. On the other hand, when the print surface Wa is at the lower limit position P1 of the focal depth df, the work distance is larger than that of the upper limit position P2, so that the size of the guide mark Ga1 is increased as shown in FIG. At this time, the guide point Gb1 is displayed on the second end portion in the major axis direction of the ellipse. That is, whether or not the printing surface Wa is at the Z-axis position where marking can be performed is taught by whether or not the guide point is located within the ellipse of the guide mark Ga2. When the print surface Wa is at the focal position P0, the guide point is displayed on the intersection of the guide marks Ga2. The cross point position of the cross is shifted in the locus T direction from the center of the ellipse of the guide mark Ga2. In this way, it is possible to cope with a case where the size of the guide mark Ga2 changes at the Z-axis position of the printing surface Wa. Note that the guide mark Ga2 shown in FIGS. 12A and 12B may be an ellipse without a cross.

Further, the guide mark Ga3 shown in FIGS. 13A and 13B includes two circles C1 and C2 having different diameters. The large-diameter circle C1 and the small-diameter circle C2 correspond to the upper limit position P2 and the lower limit position P1 of the focal depth df, respectively. When the print surface Wa is at the upper limit position P2 of the focal depth df, as shown in FIG. 13A, the guide point Gb2 is displayed on the large-diameter circle C1. On the other hand, when the print surface Wa is at the lower limit position P1 of the focal depth df, the work distance is larger than that of the upper limit position P2, so that the size of the guide mark Ga3 is increased as shown in FIG. At this time, the guide point Gb1 is displayed on the small-diameter circle C2. That is, whether or not the printing surface Wa is at the Z-axis position where marking can be performed is taught by whether or not the guide point is located in the small-diameter circle C2. Such two circles C1 and C2 can cope with a case where the size of the guide mark Ga2 changes at the Z-axis position of the printing surface Wa.

In the above embodiment, when printing a metal material, ceramic, or the like, the energy required to enable printing by changing the physical properties after irradiating the laser beam L depends on the material and the like. That is, processing is not possible at the same time as the emission of the laser light L, but processing is possible after the laser light L is emitted and a predetermined time elapses. Therefore, the control unit 17 performs drive control of the galvano motor 43 after being emitted for a predetermined time at the emission start point of the laser light L, and scans the laser light L based on the print data (processing data). However, if the laser beam L is emitted for a predetermined time while stopped at the processing start point, printing spots (processing spots) such as printing becoming thick or thin at or near the processing start point may occur depending on the setting conditions. . Further, when the irradiation time at the processing start point of the laser beam L, that is, the laser energy is insufficient, there is a possibility that even if the laser beam L is scanned, the processing start point or its vicinity is not printed (processed). In view of such problems, it is desirable to adopt the configuration described below.

When laser processing is performed by scanning the laser beam L based on the coordinate data from the start point SP0 to the end point EP0, the control unit 17 is positioned between the start point SP0 and the end point EP0 or in the direction opposite to the end point EP0 with respect to the start point SP0. Then, a correction point CP is generated. Then, the control unit 17 reciprocates the laser beam L between the correction point CP and the start point SP0, and secures a time from when the laser beam L is emitted until it can be processed.

Next, a scanning method of the laser beam L when generating the correction point CP between the start point SP0 and the end point EP0 will be described with reference to FIG. As shown in FIG. 14, the control unit 17 emits the laser beam L from the correction point CP and scans the laser beam L toward the start point SP0 (scanning Sc1). Thereafter, the control unit 17 scans the laser beam L from the start point SP0 through the correction point CP to the end point EP0 side (scanning Sc2).

By doing in this way, in scanning Sc1, time can be ensured until the process by the laser beam L becomes possible, and the printing spot in the start point SP0 and its vicinity can be suppressed. For this reason, the printing quality is improved. In addition, since the correction point CP is generated at the position processed by the laser beam L, even if the processing of the laser beam L is started at a midway position in the scanning Sc1, the printing spot is not noticeable because the processing is performed again by the scanning Sc2. .

Further, the method for generating the correction point CP between the start point SP0 and the end point EP0 may be changed as follows. That is, as shown in FIG. 15, the laser beam L is emitted from the start point SP0, and the laser beam L is scanned on the correction point CP side (scanning Sc1). Next, the control unit 17 scans the laser beam L from the correction point CP to the start point SP0 side (scanning Sc2). Thereafter, the controller 17 scans the laser beam L from the start point SP0 to the end point EP0 side through the correction point CP (scanning Sc3).

By doing in this way, in scanning Sc1, Sc2, time until processing by the laser beam L becomes possible can be ensured, and the printing spot in the start point SP0 and its vicinity can be suppressed. In addition, since the correction point CP is generated at the position where the processing with the laser beam L is performed, even if the processing of the laser beam L is started at the midway position of the scanning Sc1, since the processing is performed again with the scanning Sc2, the printed spots become inconspicuous. .

Next, an operation method of the laser light L in the case where the correction point CP is generated at a position opposite to the end point EP0 with the start point SP0 as a reference will be described with reference to FIG. As shown in FIG. 16, the control unit 17 emits the laser light L from the correction point CP and scans the laser light L toward the start point SP0 (scanning Sc1). Next, the controller 17 scans the laser beam L from the start point SP0 to the correction point CP side in the direction opposite to the end point EP0 (scanning Sc2). Thereafter, the controller 17 scans the laser beam L from the correction point CP to the end point EP0 through the start point SP0 (scanning Sc3).

By doing in this way, it is possible to secure a time until processing by the laser light L is possible in the scans Sc1 and Sc2, and it is possible to suppress print spots at the start point SP0 and its vicinity. As a method of generating the correction point CP, a method of generating the correction point CP in consideration of the energy amount of the laser light L, the material of the print surface (processed surface) of the workpiece W, etc. can be considered. Further, the configuration may be such that the user can set / change the position of the correction CP point.

In the above embodiment, the same character may be repeatedly marked in the same range, and the thickness of the line constituting the character or symbol may be changed. The specific marking method of the another example is shown below.

FIGS. 17 (a) and 17 (b) show the case where the letter “A” is marked on the workpiece W by the laser marking device. The operation shown below by the control unit 17 is executed through control of the galvano motor 43. As shown in FIG. 17A, the controller 17 scans the laser light L from the start point SP1 to the end point EP1 of the first unit marking. Thereafter, the control unit 17 moves the irradiation position of the laser light L from the end point EP1 of the first unit marking to the start point SP2 of the second unit marking without emitting the laser light L. Next, the control unit 17 scans the laser light L from the start point SP2 to the end point EP2 of the second unit marking. Thereafter, the control unit 17 moves the irradiation position of the laser light L from the end point EP2 of the second unit marking to the start point SP1 of the first unit marking without emitting the laser light L. The controller 17 can increase the thickness of the line as shown in FIG. 17B by repeating the series of steps described above. Here, when marking is repeated, for example, the print data may be disassembled for each unit marking, marked for the required number of times for each unit marking, and then transferred to the next unit marking. Hereinafter, a specific example will be described in which two reciprocal markings are performed for each unit marking as many times as necessary, that is, four times are marked for each unit marking.

For example, when marking the character “A” on the workpiece W, the control unit 17 performs one reciprocating scan between the start point SP1 and the end point EP1 of the first unit marking, as shown in FIG. More specifically, the controller 17 scans the laser beam L from the first unit marking start point SP1 to the end point EP1, and then scans the laser beam L from the first unit marking end point EP1 to the first unit marking start point SP1. Scan.

Next, as shown in FIG. 18B, the control unit 17 further performs one reciprocating scan between the start point SP1 and the end point EP1 of the first unit marking. Thereafter, the control unit 17 does not emit the laser light L, and from the first unit marking start point SP1 to the second unit marking end point EP2 as the next marking start point, as shown in FIG. 18B. The irradiation position of the laser beam L is moved.

Next, as shown in FIG. 18C, the control unit 17 performs one reciprocating scan between the start point SP2 and the end point EP2 of the second unit marking. More specifically, the controller 17 scans the laser beam L from the end point EP2 of the second unit marking to the start point SP2 of the second unit marking, and then the laser beam L from the start point SP2 of the second unit marking to the end point EP2. Scan.

Next, as shown in FIG. 18 (d), the control unit 17 further performs one reciprocating scan between the start point SP2 start point and the end point EP2 of the second unit marking. In this way, it is possible to perform marking with the same character quality as when the character “A” is marked four times. Further, it is possible to reduce the number of times of moving the irradiation position of the laser light L to the next marking start point without emitting the laser light L.

In the above embodiment, the number of locking screws 26 provided on the connector 20 is three. However, if the fixing and twisting of the fiber cable 12 can be suppressed, the number of locking screws 26 is set to one or two. Also good. Further, when the number of the locking screws 26 is four or more, by providing the locking screws 26 at equal intervals in the circumferential direction of the fiber cable 12, the fiber cable 12 can be fixed in a balanced manner or stably. Can be. Further, the rotation-preventing screw 26 may be used, for example, for aligning the optical axis of the fiber cable 12 in addition to suppressing twisting of the fiber cable 12.

In the above embodiment, the galvanometer mirrors 42 may not be a pair (two).

In the above embodiment, a beam splitter, a dichroic mirror, or the like may be used instead of the half mirror 41 as the light merging means.

The present invention is applied to the laser marking device 10 in which the main body portion 11 having the laser oscillation portion 18 and the head portion 14 are separated, but may be applied to a laser marking device in which the main body portion and the head portion are integrated. . Further, the present invention is applied to the laser marking apparatus 10 for marking patterns such as characters, symbols, and figures, but may be applied to a laser processing apparatus that performs processing such as cutting on the workpiece W.

Claims

A laser emitting unit that emits laser light; a scanning mirror that scans the laser light from the laser emitting unit; and a control unit that controls the scanning mirror, wherein the laser light from the laser emitting unit is transmitted to the scanning mirror. A laser processing apparatus for irradiating a work from a laser emission port,
The control unit increases the scanning angle of the scanning mirror as the workpiece distance increases so that the workpiece is processed at the same position and size on the processing surface of the workpiece regardless of the workpiece distance between the laser emission port and the workpiece. The laser is controlled to be narrow and the scanning speed of the scanning mirror is slow, and the scanning angle of the scanning mirror is widened and the scanning speed of the scanning mirror is fastened as the work distance is small Processing equipment.
In the laser processing apparatus of Claim 1,
A work distance setting unit for setting the work distance;
The laser processing apparatus, wherein the control unit changes a scanning angle and a scanning speed of the scanning mirror according to the work distance set by the work distance setting unit.
In the laser processing apparatus of Claim 2,
The laser machining apparatus, wherein the work distance setting unit sets the work distance according to a measurement result from a measurement unit that measures the work distance.
In the laser processing apparatus according to claim 2 or 3,
A laser processing apparatus comprising: an informing means for informing that a work distance set in the work distance setting unit is outside a reference range when the work distance is outside a preset reference range.
In the laser processing apparatus according to any one of claims 2 to 4,
A laser processing apparatus comprising invalid means for invalidating the setting of the work distance setting unit when the work distance set in the work distance setting unit is outside a preset reference range.
In the laser processing apparatus according to any one of claims 2 to 5,
With a machining range setting section that allows the user to set the machining range,
The control unit controls the processing range set by the processing range setting unit to be the same regardless of the work distance.