JP4040896B2 - Laser processing method and laser processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention irradiates a workpiece to be processed in a certain feed direction with a certain length and width, particularly a long thin plate, such as paper, with a laser beam and intersects the feed direction at equal or unequal pitches. The present invention relates to a laser processing method and apparatus for processing in a direction.
[0002]
[Prior art]
Up to now, in a laser processing apparatus that performs processing by irradiating a laser beam onto an object to be processed that has a certain length and width and is fed in a constant feeding direction, particularly a long thin plate such as paper, the object to be processed is processed. The starting position was fixed as one place fixed on the apparatus.
[0003]
[Problems to be solved by the invention]
However, in the case where the processing startable position is one place fixed on the apparatus, when trying to process at an arbitrary unequal pitch along the feed direction, this cannot be performed with a laser beam that scans at a fixed period, Further, even when machining at an equal pitch, the scan cycle must be changed each time depending on the feed speed and the pitch length. This means that a scanning mechanism that can change the scanning cycle is also necessary.
[0004]
An object of the present invention is to provide a laser processing method and a laser processing apparatus that enable processing at an equal pitch of an arbitrary interval and an unequal pitch of an arbitrary interval using a laser beam scanner that scans at a constant period. .
[0005]
[Means for Solving the Problems]
According to one aspect of the present invention, a step of preparing a processing object having a certain length and width and defining a plurality of processing start points arranged in the length direction, and a length direction of the processing object Is supported in parallel to the first direction, a workable region having a length in the first direction and a width in a direction intersecting the first direction is defined in the first direction. And when one of the processing start points enters the workable area, a laser beam is sent from one of the work start points that has entered the workable area. Scanning the direction crossing the first direction and performing laser processing, and the step of performing laser processing further includes the processing start point where the laser beam has entered the processable region The incident position of the laser beam so as to be incident on one of the first Look including the step of displacing the direction, wherein the processable region, or not included in the processed starting point processing is not completed, or one laser processing method include is provided.
[0006]
According to the laser processing method, the processing start position can be freely set in the processing region. Therefore, it is possible to scan the laser beam with a constant speed scanner that scans at a constant period, and to perform pitch processing at arbitrary intervals along the feed direction of the workpiece.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a configuration of a processing apparatus using a laser beam according to an embodiment of the present invention.
[0008]
A workpiece 14 having a certain length and width, such as paper, is fed in the direction of arrow 20 by a moving device 15, for example, a paper transport roller, and processed by, for example, a pulse laser beam emitted from the laser oscillator 10. For example, perforations are formed. As the laser oscillator 10, one capable of forming a through hole according to the material of the workpiece 14, for example, a CO ₂ laser oscillator or a solid laser oscillator is used. Furthermore, a harmonic laser beam generated by a wavelength conversion element from a solid-state laser oscillator may be used as the pulse laser beam. The laser oscillator 10 emits a pulsed laser beam in response to the trigger signal generated by the trigger calculator 17.
[0009]
The emitted pulse laser beam is collimated by a collimation lens 11 and scanned in a two-dimensional direction by an XY scanner 12. The scanned pulsed laser beam is incident on the workpiece 14 through the fθ lens 13 and, for example, perforates perpendicular to the feed direction of the workpiece 14 are machined. The fθ lens 13 keeps the moving speed of the beam spot of the pulse laser beam on the workpiece 14 constant regardless of the center and the end of the workpiece 14, and always keeps the focal point on the workpiece 14. Play a role.
[0010]
The XY scanner 12 has a pair of galvanometer mirrors M and N, and is fixed above the center of the workpiece 14 in the width direction (direction perpendicular to the feed direction 20). The galvanometer mirror M displaces the incident position of the laser beam in the feed direction 20 of the workpiece 14, and the galvanometer mirror N scans the laser beam at a constant period in the width direction (direction perpendicular to the feed direction 20). The pair of galvanometer mirrors M and N can irradiate a pulse laser beam at an arbitrary position within the processable region. The workable region has a length in the length direction of the workpiece, and has a width in a direction intersecting the length direction.
[0011]
A speed detection device 16, for example, a rotary encoder, detects the speed of the workpiece 14 conveyed by the moving device 15 and outputs a detection result. The detected speed is transmitted to the trigger calculator 17 and the scanner operation calculator 18.
[0012]
The scanner operation calculator 18 controls the operation of the XY scanner 12. Further, the conveyance amount of the workpiece 14 is obtained from the feed rate history from the machining start time.
[0013]
The storage device 19 includes a storage device 19a for storing the machining line pattern, and a storage device 19b for storing a constant scanning cycle and scanning speed of the XY scanner 12, for example, a semiconductor memory. The storage device 19a stores information on machining lines, for example, equal pitch perforations. For example, the length of the perforation cut (cut portion) and the length of the tie (uncut portion), the perforation interval (pitch) in the length direction (arrow 20 direction) of the workpiece 14 formed on the workpiece 14. ), A perforation machining start position and an end position in the width direction of the workpiece 14 (direction orthogonal to the arrow 20 direction). The storage device 19b stores a scan period and a scan speed that the XY scanner 12 performs at a constant period in a direction intersecting the feeding direction 20. As the scan speed, the component v _{x in} the width direction (direction orthogonal to the feed direction 20) of the workpiece may be stored.
[0014]
Laser processing performed by this laser processing apparatus will be described.
[0015]
FIG. 2 is a plan view of the workpiece 14 sent at a constant speed in the Y-axis direction (arrow 20 direction) at times t ₁ , t ₂ , t ₃ , and t ₄ . The intervals between time t _i and t _{i + 1} (i = 1, 2, 3) are all equal. The workpiece 14 has a certain length and width, and a plurality of workpiece start points A, B, C, and D are arranged in the length direction on the workpiece 14. A dashed line represents a processable area of the XY scanner 12. The workpiece 14 passes through the processable area of the XY scanner 12.
[0016]
Here, a case is considered in which the workpiece 14 is processed at an equal pitch, particularly in a direction perpendicular to the length direction.
[0017]
Processing start points A, B, C, and D are arranged at equal intervals in this order along one edge of the workpiece 14. t ₂ −t ₁ , t ₃ −t ₂ , and t ₄ −t ₃ are all equal, and this is a scanning period in the width direction of the XY scanner 12. Since the feed speed of the workpiece 14 is constant, the galvanometer mirrors M and N of the XY scanner 12 are swung, and the scanning direction of the laser beam is tilted from the X direction to the Y direction by an appropriate constant angle θ. The object 14 can be processed in a direction perpendicular to the length direction. A constant feed velocity v _c of the workpiece 14, when the X direction component of the scanning speed of the laser beam and v _x, theta is the angle that satisfies tanθ = v _c / v _x.
[0018]
At time t ₁ , the pulse laser beam is incident on the processing start point A, and scanning is started. At times t ₂ and t ₃ , the unmachined work start point B has not entered the workable area of the XY scanner 12. The scanner operation calculator 18 determines whether or not the unmachined work start point on the work object 14 is within the workable area of the XY scanner 12 from the transport amount of the work object 14. In this case, the scanner operation calculator 18 determines that there is no processing start point. In accordance with the determination of the scanner operation calculator 18, the trigger calculator 17 does not issue a trigger signal to the laser oscillator 10. For this reason, at time t ₂ and t ₃ , the galvanometer mirrors M and N continue to move constantly (dummy scan), but the laser processing is not performed because the pulse laser beam is not emitted.
[0019]
Processing starting at B is performed at time t ₄ when the processing start point B of the processing target 14 enters the processing possible area of the XY scanner 12. At this scan start time t ₄ , B is generally at a position different from the scan start position at time t ₁ . Therefore, the scanner operation calculator 18 determines the distance (that is, pitch) between the two processing start points A and B stored in the storage device 19a, the scanning cycle and scanning of the XY scanner 12 stored in the storage device 19b. A control signal is generated based on the speed and the feed speed of the workpiece 14 detected by the speed detector 16. As a result, the galvanometer mirror M of the XY scanner 12 swings to correct the processing start position so that the incident position of the pulse laser beam coincides with the processing start point B, and the trigger calculator 17 sends the trigger signal to the laser oscillator 10. To give. Thus, laser processing is started from the processing start point B. The same procedure is followed to perform machining starting at the next machining start points C and D.
[0020]
When laser processing is performed, the trigger computing unit 17 sets the trigger signal to the laser oscillator 10 when it corresponds to the cut position based on the perforation cut and tie length settings stored in the storage device 19a. To give. As a result, the laser oscillator 10 emits a pulsed laser beam for performing perforation processing having a set tie and cut.
[0021]
FIG. 3 shows the transition of the machining start position during this period. The alternate long and short dash line is the same workable region as in FIG. 2, and in the drawing, from the left, the machining starts at the machining start point A (time t ₁ ) and the machining starts at the second machining start point B (time t ₄ ) Indicates the machining start position at the time of machining starting from the third machining start point C and at the time of machining starting from the fourth machining start point D. After the time t ₄ , when the times t ₅ , t ₆ , t ₇ , t ₈ , and t ₉ are determined at the same intervals as before, the processing start point C is set to the XY scanner 12 at the times t ₅ and t ₆ . Since the machining area is not entered, machining starts from the machining start point C at time t ₇ . That is, the XY scanner 12 performs a dummy scan twice. However, when performing machining starting from the machining start point D, the machining start point D enters the workable area while performing a dummy scan once. Therefore, at time t ₉ , the processing start position is corrected so that the galvanometer mirror M causes the pulse laser beam to enter the processing start point D, and processing is started.
[0022]
FIG. 4 is a plan view of the workpiece 14 fed at a constant speed in the Y-axis direction (arrow 20 direction) at times t ₂₁ , t ₂₂ , t ₂₃ , t ₂₄ , and t ₂₅ . Every time interval is equal. With reference to this, the unequal pitch processing performed using the laser processing apparatus shown in FIG. 1 will be described. The inside of the one-dot chain line is the processable area of the XY scanner 12 as in FIG. A processing object 14 having a certain length and width and in which a plurality of processing start points E, F, G, H, and I are arranged in the length direction passes through a processable region of the XY scanner 12. Here again, consider a case where the workpiece 14 is machined in a direction perpendicular to the length direction. When the feed rate of the workpiece 14, if the equal v _c a constant pitch processing shown in FIG. 2, the scanning direction of the pulsed laser beam, i.e., a suitable constant angle of tilting the X-direction in the Y direction shown in FIG. 2 It is equal to θ as in the case of equal pitch machining.
[0023]
The machining start points E, F, G, H, and I are arranged in this order along one edge of the workpiece 14. The distance between the machining start points E and F is represented by EF. The same applies to the distance between the other two processing start points. Unequal pitches such that EF = GH, FG = HI, and EF ≠ FG. t ₂₂ -t ₂₁ , t ₂₃ -t ₂₂ , t ₂₄ -t ₂₃ , t ₂₅ -t ₂₄ are all equal to the scanning cycle of the XY scanner 12.
[0024]
At time t ₂₁ , the pulse laser beam is incident on the processing start point E, and scanning is started. At times t ₂₂ and t ₂₃ , the unmachined work start point F has not entered the workable area of the XY scanner 12. The scanner operation calculator 18 determines that there is no processing start point. In accordance with the determination of the scanner operation calculator 18, the trigger calculator 17 does not issue a trigger signal to the laser oscillator 10. Thus, at time t ₂₂ and t _23, although the galvano-mirror M and N continues to constant motion (dummy scan), the pulse laser beam is not emitted, the laser processing is not performed.
[0025]
Processing starts at the processing start point F at time t ₂₄ when the processing start point F of the processing object 14 enters the processing possible area of the XY scanner 12. At the scan start time t ₂₄ , the processing start point B is generally at a position different from the scan start position at the time t ₂₁ . Therefore, the scanner operation calculator 18 determines the distance (that is, pitch) between the two processing start points E and F stored in the storage device 19a, the scanning cycle and scanning of the XY scanner 12 stored in the storage device 19b. A control signal is generated based on the speed and the feed speed of the workpiece 14 detected by the speed detector 16. As a result, the galvanometer mirror M of the XY scanner 12 is swung to correct the processing start position so that the incident position of the pulse laser beam coincides with the processing start point F, and the trigger calculator 17 sends the trigger signal to the laser oscillator 10. To give. Thus, laser processing is started from the processing start point F. At time t ₂₅ , the processing start point G enters the processable region of the XY scanner 12, so laser processing starts from G through the same procedure. Thereafter, the same procedure is repeated for the processing start points H and I.
[0026]
In this way, by displacing the machining start position in the feed direction of the workpiece 14, using a constant speed scanner that scans at a high speed with a constant scanning cycle, the workpiece 14 is given an equal pitch and an arbitrary pitch. It is possible to perform processing with an unequal pitch.
[0027]
The case where the feed speed of the workpiece 14 is constant has been described so far, but the present invention is not limited to that range. Even when there is a change in the feed speed of the workpiece 14, appropriate machining can be performed based on the speed detected by the speed detection device 16.
[0028]
The description will be continued with reference to FIG. For example, it is assumed that the feed speed of the workpiece 14 is increased during machining from the time t ₂₄ to t ₂₅ . This change in the feed rate is detected by the speed detection device 16 and transmitted to the scanner operation calculator 18. In order to process the workpiece 14 in a direction perpendicular to the length direction, the angle θ shown in FIG. 2 must be increased. Moreover, this angle must be changed every moment according to the change in the feed rate. The scanner operation calculator 18 sends a control signal to the XY scanner 12 based on the feed speed of the workpiece 14 and the scanning speed of the pulse laser beam stored in the storage device 19b. The pulse laser beam during scanning always adjusts the scanning direction by adding a new oscillation corresponding to the speed change to the galvanometer mirror M for displacing the incident position of the laser beam in the length direction of the workpiece 14. Is done. As a result, machining in the direction perpendicular to the length direction of the workpiece 14 is realized.
[0029]
The same applies when the feed speed of the workpiece 14 decreases. In this case, the scan is performed with the angle θ shown in FIG.
[0030]
The above control is also effective for speed changes at the start and end of conveyance of the workpiece 14.
[0031]
In the above embodiment, the XY scanner 12 including a pair of galvanometer mirrors M and N is used. However, the XY scanner 12 scans the pulse laser beam in the X direction with a polygon mirror and scans in the Y direction with a galvanometer mirror. A scanner may be used.
[0032]
Furthermore, in the above-described embodiment, the laser processing applied to the workpiece 14 is waited by stopping the oscillation of the laser oscillator 10, but the pulse laser beam emitted from the laser oscillator 10 is interrupted in the middle and the workpiece 14 is blocked. By providing a shutter mechanism that prevents it from reaching, laser processing may be waited.
[0033]
FIG. 5 is a block diagram of a laser processing apparatus according to an embodiment of the present invention that uses a focus lens 21 and a lens displacement mechanism 22 that displaces the focus lens 21 in the optical axis direction instead of the fθ lens 13. is there. The pulse laser beam emitted from the laser oscillator 10 is collimated by the collimation lens 11, collected by the focus lens 21 so as to be focused on the workpiece 14, and then enters the XY scanner 12. The XY scanner 12 includes a pair of oscillating galvanometer mirrors M and N, and scans a pulse laser beam on the workpiece 14 in a two-dimensional direction. The lens displacement mechanism 22 moves the focus lens 21 in the optical axis direction according to a control signal given by the scanner operation calculator 18. The scanner operation calculator 18 sends a signal for displacing the focus lens 21 to the lens displacement mechanism 22 in accordance with the position where the pulse laser beam is irradiated, that is, in synchronization with the scanning of the XY scanner 12. Although the distance from the focus lens 21 to the workpiece 14 varies according to the irradiation position of the laser beam, the pulse laser beam is always focused on the workpiece 14 due to the displacement of the focus lens 21.
[0034]
Although the present invention has been described with reference to the embodiments, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like are possible.
[0035]
【The invention's effect】
As described above, according to the present invention, the region that extends in the direction in which the workpiece is fed and the direction that intersects the direction can be set as a workable region, and the machining start position can be freely set therein. As a result, it is possible to perform pitch processing at arbitrary intervals using a constant speed scanner suitable for high speed scanning.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a laser processing apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view of an object to be processed for explaining an equal pitch laser processing method performed by a laser processing apparatus according to an embodiment of the present invention.
FIG. 3 is a plan view of an object to be machined for explaining an equal pitch laser machining method performed by a laser machining apparatus according to an embodiment of the present invention.
FIG. 4 is a plan view of an object to be machined for explaining an unequal pitch laser machining method performed by a laser machining apparatus according to an embodiment of the present invention.
FIG. 5 is a block diagram in which a partial configuration of the laser processing apparatus according to the embodiment of the present invention is changed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Laser oscillator 11 Collimation lens 12 XY scanner 13 f (theta) lens 14 Work object 15 Moving apparatus 16 Speed detection apparatus 17 Trigger calculator 18 Scanner operation calculator 19, 19a, 19b Memory | storage device 20 Arrow 21 Focus lens 22 Lens displacement mechanism

Claims (7)

Preparing a workpiece having a certain length and width and defining a plurality of workpiece start points arranged in the length direction;
Supporting the length direction of the workpiece to be parallel to the first direction, having a length in the first direction, and having a width in a direction intersecting the first direction Sending the workpiece to pass through the possible area in the first direction;
When one of the processing start points enters the workable region, a laser beam is scanned from one of the processing start points that has entered the workable region in a direction intersecting the first direction, A step of performing laser processing,
The step of performing the laser processing further displaces the incident position of the laser beam in the first direction so that the laser beam is incident on one of the processing start points that have entered the processable region. A laser processing method including a process, wherein the processing start area that has not been processed is not included or is included in the processable region. The laser processing method according to claim 1, wherein the laser beam is scanned at a constant period in a direction intersecting with the first direction. A laser light source for emitting a laser beam;
First storage means for storing a first period and a first speed;
An optical system for causing a laser beam emitted from the laser light source to reach a point in a workable region having a length in a first direction and having a width in a direction intersecting the first direction. First scanning means for scanning the laser beam at a first period and a first speed stored in the first storage means in a direction crossing the first direction; and The optical system including second scanning means for moving a reaching point in the first direction;
Moving means for moving the workpiece so that the workpiece passes through the workable region in the first direction;
A laser processing apparatus. Further, the laser processing apparatus detects a speed in the first direction of the workpiece to be moved by the moving means,
Second storage means for storing distances between a plurality of processing start points arranged on the processing object;
Between the speed detected by the speed detection means, the first cycle and the first speed stored in the first storage means, and the processing start point stored in the second storage means First control means for controlling the first and second scanning means based on the distance of
The laser processing apparatus of Claim 3 which has these. Further, the laser processing apparatus includes a second control means for controlling the laser light source,
The first control means determines whether or not the machining start point closest to the entry into the workable area among the plurality of work start points has entered the workable area, and is subject to determination When it is determined that the processing start point that has become not entered the workable region and there is no work start point that has not been processed in the workable region, the second processing point The laser processing apparatus according to claim 3 or 4, wherein the control means does not emit the laser beam from the laser light source.   The laser processing apparatus according to any one of claims 3 to 5, further comprising a processing standby mechanism that does not irradiate the processing target with the laser beam. Furthermore, the laser processing apparatus, a focus lens for focusing the laser beam on the surface of the workpiece,
A lens displacement mechanism for displacing the focus lens in a direction parallel to the optical axis of the focus lens;
The first control means synchronizes the displacement of the focus lens by the lens displacement mechanism with the scanning by the first and second scanning means. Laser processing equipment.

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