JP2003290960A - Laser beam machining method and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform laser beam machining with even pitches of arbitrary intervals and uneven pitches of arbitrary intervals using a laser beam scanner scanning at a constant period. <P>SOLUTION: A machining object 14 is prepared having a specific length and a width and a plurality of machining starting points A, B, C and D demarcated and disposed in the length direction. The machining object 14 is supported with its length direction to be parallel to the direction Y, and is sent to pass a machinable region in the direction Y having a specific length in the direction Y and a specific width in the direction crossing the direction Y. When one of the machining starting points enters the machinable region, an incident position of the laser beam scanned in the direction crossing the direction Y at a constant period is displaced in the direction Y so that the laser beam is made incident on the machining starting point entering the machinable region to scan from the machining starting point entering the machinable region. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a work piece having a certain length and width and fed in a constant feed direction, in particular, a long thin plate, such as paper, by irradiating it with a laser beam to obtain an equal pitch or an unequal pitch. The present invention relates to a laser processing method and device for performing processing in a direction intersecting the feed direction.

[0002]

2. Description of the Related Art Up to now, in a laser processing apparatus which irradiates a laser beam to a processing object having a certain length and width and fed in a constant feeding direction, particularly a long thin plate such as paper, The position to start processing on the object was set to one position fixed on the device.

[0003]

However, in the case where the machining startable position is one position fixed on the apparatus, if machining is performed at an arbitrary unequal pitch along the feed direction,
This cannot be done with a laser beam that scans at a constant cycle, and even if processing is performed at equal pitches, the scan cycle must be changed each time depending on the feed rate and the pitch length. That means
There was also a need for a scan mechanism that can change the scan cycle.

An object of the present invention is to provide a laser processing method and a laser processing apparatus which enable processing of an equal pitch at arbitrary intervals and unequal pitch at arbitrary intervals by using a laser beam scanner which scans at a constant cycle. That is.

[0005]

According to one aspect of the present invention, there is provided a step of preparing an object to be machined having a certain length and width and defining a plurality of starting points to be machined arranged in the longitudinal direction. , The object to be machined is supported so that its longitudinal direction is parallel to the first direction, has a length in the first direction, and has a width in a direction intersecting with the first direction. A step of sending the object to be processed so as to pass through the processable area in the first direction; and when one of the processing start points enters the processable area, a laser beam is incident on the processing start point. Thus, there is provided a laser processing method including a step of displacing the laser beam and a step of performing laser processing by scanning a laser beam in a direction intersecting the first direction from the processing start point.

According to the laser processing method, the processing start position can be freely set in the processable area. Therefore, it is possible to scan the laser beam with a constant-speed scanner that scans at a constant cycle and perform pitch processing at arbitrary intervals along the feed direction of the object to be processed.

[0007]

1 is a block diagram showing the configuration of a processing apparatus using a laser beam according to an embodiment of the present invention.

A workpiece 14 having a certain length and width,
For example, the paper is sent in the direction of arrow 20 by a moving device 15, for example, a paper carrying roller, and processed, for example, perforated by the pulse laser beam emitted from the laser oscillator 10. Laser oscillator 10
For this, a material capable of forming a through hole depending on the material of the object to be processed 14, such as a CO ₂ laser oscillator or a solid-state laser oscillator, is used. Further, as the pulsed laser beam, a harmonic laser beam generated by a wavelength conversion element from a solid-state laser oscillator may be used. The laser oscillator 10 receives the trigger signal from the trigger calculator 17 and emits a pulse laser beam.

The emitted pulsed laser beam is collimated by a collimation lens 11 and scanned in a two-dimensional direction by an XY scanner 12. The scanned pulse laser beam is incident on the object to be processed 14 via the fθ lens 13 and, for example, a perforation perpendicular to the feed direction of the object to be processed 14 is processed. The fθ lens 13 keeps the moving speed of the beam spot of the pulse laser beam constant on the object to be processed 14 regardless of the central portion and the end of the object to be processed 14 and keeps the focus on the object to be processed 14 at all times. Play a role.

The XY scanner 12 has a pair of Galvano mirrors M and N, and is arranged in the width direction (feed direction 2) of the workpiece 14.
It is fixed in the upper part near the center (direction orthogonal to 0).
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 in the width direction (direction orthogonal to the feed direction 20) at a constant cycle. With this pair of galvanometer mirrors M and N, it is possible to irradiate the pulsed laser beam to an arbitrary position within the processable region. The machinable region has a length in the longitudinal direction of the object to be machined and a width in a direction intersecting the length direction.

The speed detecting device 16, for example, a rotary encoder detects the speed of the workpiece 14 conveyed by the moving device 15 and outputs the detection result. The detected speed is the trigger calculator 17 and the scanner operation calculator 18
Be transmitted to.

The scanner operation calculator 18 is the XY scanner 1.
2 control the operation. Further, the transport amount of the processing object 14 is obtained from the feed speed history from the processing start time.

The storage device 19 is composed of a storage device 19a for storing a machining line pattern and a storage device 19b for storing a constant scan cycle and a 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 lengths of cuts (cut portions) and ties (uncut portions) of perforations, perforation intervals (pitch) formed on the workpiece 14 in the length direction (arrow 20 direction) of the workpiece 14. ), A perforation processing start position and an end position in the width direction of the processing object 14 (direction orthogonal to the arrow 20 direction). Further, the storage device 19b stores a scan cycle and a scan speed that the XY scanner 12 performs at a constant cycle in a direction intersecting the feed direction 20. As the scan speed, the component v _{x in} the width direction of the object to be processed (direction orthogonal to the feed direction 20) may be stored.

The laser processing performed by this laser processing apparatus will be described.

FIG. 2 shows the times t ₁ , t _{2 of} the workpiece 14 fed at a constant speed in the Y-axis direction (arrow 20 direction).
It is a plan view of t _3, and t _4. Time t _i and t
The intervals with _{i + 1} (i = 1, 2, 3) are all equal. The processing object 14 has a certain length and width, and a plurality of processing start points A, B, C, D are arranged on the processing object 14 in the length direction. The inside of the one-dot chain line represents the workable area of the XY scanner 12. The processing object 14 passes through the processable area of the XY scanner 12.

Here, let us consider a case where the object 14 is machined at a constant pitch, particularly in a direction perpendicular to the length direction.

The processing start points A, B, C and D are arranged in this order at equal intervals along one edge of the object to be processed 14. t
_{2 -t 1, t 3 -t 2} , t 4 -t 3 we are all equal, which is X
This is the scanning period in the width direction of the Y scanner 12. Since the feed speed of the object to be processed 14 is constant, the galvanometer mirrors M and N of the XY scanner 12 are swung to tilt the scanning direction of the laser beam from the X direction to the Y direction by an appropriate constant angle θ to perform the processing. It is possible to process the object 14 in a direction perpendicular to the length direction. When the constant feed speed of the processing object 14 is v _c and the X-direction component of the scanning speed of the laser beam is v _x , θ is an angle that satisfies tan θ = v _c / v _x .

At time t ₁ , the pulse laser beam is incident on the processing start point A and scanning is started. Time t
_{At 2} and t ₃ , the unprocessed starting point B does not enter the processable area of the XY scanner 12. The scanner operation calculator 18 determines whether or not the unprocessed starting point on the workpiece 14 is in the machinable area of the XY scanner 12 based on the carry amount of the workpiece 14. In this case, the scanner operation calculator 18 determines that there is no processing start point.
According to the determination made by the scanner operation calculator 18, the trigger calculator 17 does not issue a trigger signal to the laser oscillator 10. Therefore, at times t ₂ and t ₃ , the galvanomirrors M and N continue to move in a certain manner (dummy scan), but the pulse laser beam is not emitted, so that laser processing is not performed.

At time t ₄ when the processing start point B of the processing object 14 enters the processable area of the XY scanner 12,
Processing starting from B is performed. 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
Is the distance (that is, the pitch) between the two processing start points A and B stored in the storage device 19a, the storage device 19
A control signal is issued based on the scanning cycle and scanning speed of the XY scanner 12 and the feed speed of the workpiece 14 detected by the speed detection device 16 stored in b. as a result,
The galvanometer mirror M of the XY scanner 12 oscillates to correct the processing start position so that the incident position of the pulsed laser beam coincides with the processing start point B, and the trigger calculator 17 gives a trigger signal to the laser oscillator 10. As a result, 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.

When laser processing is performed, the trigger calculator 17 sends a trigger signal when the cutting position corresponds to the cut position based on the perforation cut and tie length settings stored in the storage device 19a. It is given to the laser oscillator 10. As a result, the laser oscillator 10 emits a pulsed laser beam which is perforated and has a set tie and cut.

FIG. 3 shows the transition of the machining start position during this period. The inside of the one-dot chain line is the same machinable region as in FIG. 2, and in the figure, from the left, in the machining starting at the machining starting point A (time t ₁ ), during the machining starting at the second machining starting point B (time t ₄ ) It represents the machining start position when machining starts at the third machining start point C and when machining starts at the fourth machining start point D. Also the time t ₄ after the same interval as far as the time _{t 5, t 6, t 7} , t 8, t 9 when determining the respective times, the time t _5, t XY scanner 12 is to be processed starting point C in ₆
Since it has not entered the processable area of
The processing is started from at time t ₇ . That is, the XY scanner 12 performs the dummy scan twice. However, when performing the machining starting at the machining start point D, the machining start point D enters the machinable region while performing the dummy scan once. Therefore, at time t ₉ ,
The galvano mirror M corrects the processing start position so that the pulsed laser beam is incident on the processing start point D, and the processing is started.

FIG. 4 shows times t ₂₁ , t ₂₂ and t of the workpiece 14 fed at a constant speed in the Y-axis direction (arrow 20 direction).
₂₃ is a plan view of t _24, and t _25. All time intervals are equal. The unequal pitch processing performed using the laser processing apparatus shown in FIG. 1 will be described with reference to this. The area within the dashed-dotted line is the same machinable area of the XY scanner 12 as in FIG. A processing object 14 having a certain length and width and having a plurality of processing start points E, F, G, H, and I arranged in the length direction passes through the processable area of the XY scanner 12. Here, too, consider a case where the object to be processed 14 is processed in a direction perpendicular to the length direction. If the feed speed of the object to be processed 14 is v _c, which is equal to that in the case of the equal pitch processing shown in FIG. 2, an appropriate constant angle for inclining from the X direction to the Y direction in the scanning direction of the pulse laser beam is also shown in FIG. The angle θ is the same as in the case of equal pitch machining.

The starting points E, F, G, H and I to be processed are arranged in this order along one edge of the object to be processed 14. The distance between the processing start points E and F is represented as EF. The same applies to the distance between the other two processing start points. EF = GH, FG
= HI, and unequal pitch such that EF ≠ FG. t
All _{22 -t 21, t 23 -t 22} , t 24 -t 23, t 25 -t 24 is equal to the scanning period of the XY scanner 12.

At time t ₂₁ , the pulsed laser beam is incident on the processing starting point E and scanning is started. Time t
_{At 22} and t ₂₃ , the unprocessed starting point F does not enter the processable area of the XY scanner 12. The scanner operation calculator 18 determines that there is no processing start point. According to the determination made by the scanner operation calculator 18, the trigger calculator 17 does not issue a trigger signal to the laser oscillator 10. Therefore, at the times t ₂₂ and t ₂₃ , the galvano mirrors M and N continue a constant movement (dummy scan),
Laser processing is not performed because the pulsed laser beam is not emitted.

At time t ₂₄ when the processing start point F of the processing object 14 enters the processable area of the XY scanner 12,
The processing starting from the processing start point F is performed. 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 . Then, the scanner operation calculator 18 causes the distance (that is, the pitch) between the two processing start points E and F stored in the storage device 19a, the scanning cycle and the scanning of the XY scanner 12 stored in the storage device 19b. Speed and speed detection device 16
A control signal is issued based on the feed speed of the processing target 14 detected in step. As a result, the galvanometer mirror M of the XY scanner 12 oscillates to correct the processing start position so that the incident position of the pulsed laser beam coincides with the processing start point F, and the trigger calculator 17 sends a trigger signal to the laser oscillator 1.
Give to 0. As a result, laser processing is started from the processing start point F. Even at time t ₂₅ , the processing start point G has entered the processable area of the XY scanner 12, so
Laser processing is started from G through the same procedure. Hereinafter, the same procedure is repeated for the processing start points H and I.

In this way, the processing start position is set to the object 1 to be processed.
By displacing in the feeding direction of 4, it is possible to process the object to be processed 14 at equal intervals and unequal pitches by using a constant speed scanner that scans at high speed in a constant scanning cycle. To do.

Up to this point, the case where the feed rate of the workpiece 14 is constant has been described, but the present invention is not limited to this range. Even if there is a change in the feed speed of the processing object 14, it is possible to perform appropriate processing based on the speed detected by the speed detection device 16.

The description will be continued with reference to FIG. For example, it is assumed that the feed rate of the workpiece 14 is increased during the processing from the time t ₂₄ to the time t ₂₅ . This change in the feed speed is detected by the speed detection device 16, and the scanner operation calculator 1
8. In order to process the object 14 to be processed in the 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 of the feed rate. The scanner operation calculator 18 is configured to detect the feed speed of the workpiece 14 and the storage device 19b.
A control signal is sent to the XY scanner 12 based on the scanning speed of the pulsed laser beam stored in. By adding a new swing 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 processing object 14, the pulsed laser beam during scanning always adjusts the scanning direction. To be done. As a result, the workpiece 1
Processing in the direction perpendicular to the length direction of 4 is realized.

The same applies to the case where the feed rate of the workpiece 14 decreases. In this case, the scan is performed with the angle θ shown in FIG. 2 reduced.

The above control is also effective for speed changes at the start and end of the conveyance of the workpiece 14.

In the above embodiment, the XY scanner 12 including the pair of galvanometer mirrors M and N is used. However, the scanning of the pulse laser beam in the X direction is performed by the polygon mirror, and the scanning in the Y direction is performed by the galvanometer mirror. You may use the XY scanner performed by.

Further, in the above-described embodiment, the oscillation of the laser oscillator 10 is stopped to wait for the laser processing to be performed on the object to be processed 14. However, the pulse laser beam emitted from the laser oscillator 10 is interrupted midway to be processed. By providing a shutter mechanism that prevents the object 14 from reaching,
You may wait for laser processing.

FIG. 5 shows a laser processing apparatus according to an embodiment of the present invention using a focus lens 21 and a lens displacement mechanism 22 for displacing the focus lens 21 in the optical axis direction, instead of the fθ lens 13. It is a block diagram. The pulsed laser beam emitted from the laser oscillator 10 is collimated by the collimation lens 11, focused by the focus lens 21 so as to be focused on the workpiece 14, and then incident on the XY scanner 12. The XY scanner 12 is configured to include a pair of oscillating galvanometer mirrors M and N, and outputs a pulse laser beam to an object 14 to be processed.
Scan above in two dimensions. Lens displacement mechanism 22
Moves the focus lens 21 in the optical axis direction in accordance with a control signal provided by the scanner operation calculator 18. The scanner operation calculator 18 sends to the lens displacement mechanism 22 a signal for displacing the focus lens 21 in synchronization with the position irradiated with the pulse laser beam, that is, in synchronization with the scanning of the XY scanner 12. Although the distance from the focus lens 21 to the processing object 14 varies depending on the irradiation position of the laser beam, the pulse laser beam is always focused on the processing object 14 due to the displacement of the focus lens 21.

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 can be made.

[0035]

As described above, according to the present invention,
An area that extends in the feed direction of the object to be processed and a direction that intersects the direction is defined as a machinable area, and the machining start position can be freely set in the area. As a result, it is possible to perform pitch processing at arbitrary intervals by using a constant speed scanner suitable for high speed scanning.

[Brief description of 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 a laser processing method of equal pitch performed by the laser processing apparatus according to the embodiment of the present invention.

FIG. 3 is a plan view of an object to be processed for explaining a laser processing method of equal pitch performed by the laser processing apparatus according to the embodiment of the present invention.

FIG. 4 is a plan view of an object to be processed for explaining a laser processing method of an unequal pitch performed by the laser processing apparatus according to the 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]

10 Laser oscillator 11 Collimation lens 12 XY scanner 13 fθ lens 14 Object to be processed 15 Moving device 16 Speed detector 17 Trigger calculator 18 Scanner operation calculator 19, 19a, 19b storage device 20 arrow 21 Focus lens 22 Lens displacement mechanism

Claims (9)

[Claims] 1. A step of preparing a processing object having a certain length and a width and defining a plurality of processing start points arranged in the length direction, wherein the processing object has a first longitudinal direction. So as to pass in the first direction through a machinable region having a length in the first direction and a width in a direction intersecting the first direction. A step of sending the processing target to the processing target, and when one of the processing start points enters the processable area, a laser beam is emitted from the processing start point that has entered the processable area in the first direction. A laser processing method, comprising the steps of scanning in a direction intersecting with each other and performing laser processing. 2. The laser beam is scanned at a constant cycle in a direction intersecting with the first direction, and in the step of performing the laser processing, the laser beam further enters the processable region. The laser processing method according to claim 1, comprising a step of displacing an incident position of the laser beam in the first direction so that the laser beam is incident on the processing start point. 3. The laser processing method further comprises a step of detecting a speed at which the object to be processed is sent in the first direction, and the lasers arranged on the object to be processed based on the detected speed. The laser processing method according to claim 1, further comprising a step of determining whether or not a processing start point has entered the processable area. 4. The laser processing method does not irradiate the object to be processed with a laser beam when the processing start point is determined not to enter the processable area in the determination step. The laser processing method according to claim 3, including a step. 5. A laser light source for emitting a laser beam, and a laser beam emitted from the laser light source has a length in a first direction and a width in a direction intersecting with the first direction. An optical system for arriving at a point in a processable region, the first scanning scanning the laser beam at a constant first period and at a constant first speed in a direction intersecting the first direction. Means, and the optical system including a second scanning means for moving the arrival point of the laser beam in the first direction, so that an object to be processed passes through the processable region in the first direction, A laser processing apparatus comprising: a moving unit that moves the object to be processed. 6. The laser processing apparatus further includes speed detecting means for detecting a speed of the processing object moved by the moving means in the first direction, and a plurality of the plurality of processing elements arranged on the processing object. First storage means for storing information for specifying the position of the processing start point; second storage means for storing the first cycle and the first speed; and the speed The speed detected by the detection means, the position of the processing start point stored in the first storage means, the first cycle stored in the second storage means, and the first
6. The laser processing apparatus according to claim 5, further comprising: first control means for controlling the first and second scanning means based on the speed of the. 7. The laser processing apparatus further includes second control means for controlling the laser light source, wherein the first control means determines whether or not the processing start point has entered the processable area. The laser processing apparatus according to claim 5, wherein the second control unit does not cause the laser beam to be emitted from the laser light source based on the determination result. 8. The laser processing apparatus according to claim 5, further comprising a processing standby mechanism that does not irradiate the object to be processed with the laser beam. 9. The laser processing apparatus further comprises a focus lens for focusing the laser beam on the surface of the object to be processed, and a lens for displacing the focus lens in a direction parallel to the optical axis of the focus lens. 9. A displacement mechanism, wherein 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. The laser processing apparatus described in.