JP3204937B2 - Irradiation control method of laser light for indicating processing point in laser processing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device which is suitable for a laser processing apparatus which introduces a laser beam emitted from a laser oscillator into a processing head and scans a workpiece by scanning the laser beam. The present invention relates to a method for controlling irradiation of a processing point indicating laser beam in a processing apparatus.

[0002]

2. Description of the Related Art Conventionally, there has been known a laser processing method in which a workpiece is irradiated with a laser beam, and the workpiece is heated and evaporated or melted to perform processing such as cutting or welding. The laser processing device used at this time introduces the laser beam emitted from the laser oscillator into the processing head, and the laser beam is applied to the workpiece via the focal length adjusting means and the scanning means provided in the processing head. It is configured to focus the laser light.

For example, in a case where a laser processing apparatus is used as a welding robot in a production line of an automobile, a moving path of a laser beam irradiation point on a workpiece to the welding robot prior to an actual welding operation. Is taught and stored in a computer (controller), that is, a teaching operation (teaching operation) is required.

[0004] At the time of a teaching operation, a low-output visible laser light such as a semiconductor laser is used instead of a high-output laser light (a processing laser light) such as a CO ₂ laser used in actual processing. (Referred to as a processing point indicating laser beam). At the time of this teaching operation, the processing point indicating laser light is moved along a movement path (including a movement path for processing and a movement path only for movement).
It is controlled to irradiate the top continuously.

After the teaching operation is completed, the teaching path is illuminated continuously with a laser beam for designating a machining point in order to check the suitability of the movement path of the laser beam irradiation point stored in the computer. It is conceivable to perform a teaching operation confirming operation for confirming.

[0006]

However, in the teaching operation confirmation work, if the processing point indicating laser light is controlled to continuously irradiate the workpiece, it is simply irradiation for processing movement. It was recognized that it was not possible to determine whether the irradiation was only for movement.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a laser processing apparatus capable of easily determining whether or not a part is processed by a processing laser beam when confirming a teaching operation. It is an object of the present invention to provide a method of controlling the irradiation of a laser beam for indicating a processing point in the above.

Further, the present invention provides an irradiation control method of a laser beam for designating a processing point in a laser processing apparatus, which makes it possible to clearly distinguish irradiation for processing movement when confirming a teaching operation. The purpose is to do.

[0009]

According to the present invention, at the time of confirming the teaching operation of the laser processing apparatus, the irradiation mode for the workpiece by the laser beam for designating the processing point is changed between the processed part and the non-processed part of the workpiece. Like that.

For this reason, at the time of confirming the teaching operation, it is possible to easily determine whether or not the irradiation part is a part to be processed by the processing laser light by confirming the irradiation mode at the irradiation part of the processing point indicating laser light. be able to. In other words, at the time of confirming the teaching operation, it can be clearly distinguished whether or not the irradiation is for processing movement.

For example, when a teaching operation of a laser processing apparatus is confirmed, a workpiece is continuously irradiated with a laser beam for designating a processing point as a continuous irradiation on a processed portion of the workpiece, and a non-processed portion is irradiated on a non-processed portion. By controlling the irradiation mode of the processing point indicating laser light to be non-irradiation and not irradiating the workpiece, it is possible to easily determine whether or not the processing point is a processing portion. In this case, even when the workpiece is irradiated with the flashing laser beam as the irradiation mode of the processing point instruction laser light on the non-processed portion on the non-processed portion, the processed portion and the non-processed portion are clearly distinguished. Can be.

If necessary, a combination of continuous irradiation, blinking irradiation, and non-irradiation may be applied to the processed portion and the non-processed portion. That is, the non-processed portion is set to blinking or non-irradiation when the processed portion is continuously irradiated, the non-processed portion is set to continuous irradiation or non-irradiation when the processed portion is flashed, and Can be controlled to be continuous irradiation or blinking irradiation.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a production line 10 to which an embodiment of the present invention is applied.

The production line 10 basically includes a production line 1 including a transport control of a workpiece 12 such as an automobile.
Master controller 14 which is the overall control device
And a robot controller 16 also serving as a laser controller (laser controller) started by the master controller 14, a welding robot 18 whose operation is controlled by the robot controller 16, and a laser control panel on which a laser oscillator 50 is mounted. 20.

The robot controller 16 has a CPU 22 which is a central processing unit having an arithmetic control function, and a ROM (read only memory) 25 in which a control program is stored via a bus 24 for this CPU 22, A RAM (random access memory) 26 as a storage unit to be used is connected, and a hard disk device 28 as a large-capacity storage device for storing teaching data and the like is connected via an interface 30.

The bus 24 has interfaces 32, 3
A master controller 14, a welding robot 18, and a teaching box 38 for performing a teaching operation or the like are connected to the master controller 14 via a communication line 4, 36, and a communication line.

Further, the bus 24 has an interface 4
In order to switch the operation mode of the welding robot 18 via 0, an operation mode changeover switch 42, which is a quadruple push button switch capable of selecting and pressing (turning on) only one arbitrary push button. Is connected. The operation mode changeover switch 42 is connected to the robot controller 16.
It is attached to the panel surface. The operation style is
Operation mode changeover switches 42A, 42B, 42C, 42D
In response to the respective ON states, the OFF operation (non-operation) mode in which the welding robot 18 is in the non-operation state, the teaching operation mode for obtaining the teaching data, and the teaching for judging the appropriateness of the obtained teaching data. It is possible to select a welding operation mode for actually welding the workpiece 12 with the laser beam L based on the operation confirmation mode and the confirmed teaching data.

Furthermore, when the teaching operation confirmation mode is selected by the operation mode switch 42 on the bus 24, in other words, the operation mode switch 42
An irradiation mode changeover switch 43, which is an interlocking push button switch for changing the irradiation mode of the processing point indicating laser beam Lp (described later), which is valid only when C is in the ON state, is connected via an interface 45. ing.
Similarly to the operation mode changeover switch 42, the irradiation mode changeover switch 43 is attached to the panel surface of the robot controller 16, and one of the irradiation mode changeover switches 43 is provided.
When A is in the ON state, the processing portion is continuously irradiated by the processing point indicating laser light Lp, the non-processing portion is set to the non-irradiation irradiation mode A, and the other irradiation mode switch 43B is turned on. , The processing portion is continuously irradiated with the processing point indicating laser light Lp,
The non-processed portion is set to the irradiation mode B in which the blinking irradiation is performed.

The processing head 52 attached to the tip of an arm (not shown) of the welding robot 18 includes a scanning optical system 56 and an optical system driving motor 58 for driving the scanning optical system 56. The scanning optical system 56 is driven by an optical system driving motor 58, and outputs a high-power laser beam (processing laser beam) output from a laser oscillator 50 having a CO ₂ laser oscillation tube and introduced through a laser shutter 54. In this embodiment, a laser beam for welding) L
The workpiece 12 is scanned with the processing point indicating laser light Lp, which is a low-output visible laser light introduced from the laser pointer 62 having the semiconductor laser 1 or a semiconductor laser. in this case,
At the same time as the scanning, the laser light L1 and Lp (the reference numeral is L when there is no need to distinguish between them), the tool center point (processing point) TCP on the workpiece 12 has a focal point (convergence point). Is adjusted by the processing head 52 so that

The scanning and focus adjustment of the laser beam L by the processing head 52 are performed by the robot controller 1 as described later.
6 through an interface 60 connected to the bus 24.

A laser pointer 62 for emitting the processing point indicating laser light Lp is attached to the rod 66. The expansion and contraction of the rod 66 in the direction of the arrow D or the direction of the arrow U is performed by a servo motor (not shown) included in the pointer control circuit 64 attached to the welding robot 18 through the interface 68 connected to the bus 24 of the robot controller 16. It is controlled by being controlled through. When the rod 66 is extended in the direction of arrow D, the optical axis of the processing point indicating laser light Lp output from the laser pointer 62 is made coaxial with the optical axis of the high-power laser light L1 for processing.

The laser pointer 62 has its light emission mode (irradiation mode when considered on the workpiece 12) controlled by the robot controller 16 via a pointer control circuit 64 via an interface 68. In this embodiment, the emission mode (irradiation mode) of the laser pointer 62 includes a continuous emission mode (continuous emission mode) using a constant output laser beam Lp, a blinking emission mode (flashing emission mode) that modulates the intensity of the output, and a non-emission mode (irradiation mode). Non-irradiation) mode. In this case, in the off operation mode in which the operation mode switch 42A is turned on or in the welding operation mode in which the operation mode switch 42D is turned on, the light emission mode is the non-light emission mode. In the teaching operation mode in which the operation mode switch 42B is turned on, the light emission mode is the continuous light emission mode. Further, at the time of the teaching operation confirmation in which the operation mode changeover switch 42C is turned on, the irradiation mode (light emission mode) A (the processing portion is the continuous irradiation mode, the non-processing mode) depends on the above-mentioned irradiation mode selection switches 43A and 43B. The part is set to the non-irradiation mode or the irradiation mode (light emission mode) B (the processing part is the continuous irradiation mode, and the non-processing part is the flashing irradiation mode).

The laser shutter 54 is arranged on the laser control panel 20 including the laser power supply connected via the interface 79 of the robot controller 16. The laser shutter 54 includes an interface 70 of the robot controller 16 and a shutter control circuit 72.
The operation is controlled through. The laser shutter 54 controls the shutter control circuit 72 when shutting off the laser light L1.
, A total reflection mirror (not shown) inclined at 45 ° to the optical axis of the laser light L1 is inserted so as to block the optical path, and the laser light L1 reflected by the total reflection mirror is It is controlled to irradiate a laser light absorption mechanism (not shown). The laser light absorption mechanism includes a heat conversion mechanism (not shown) that converts the irradiated laser light L1 into heat, and a cooling mechanism (not shown) that cools the heat conversion mechanism.

FIG. 2 shows a scanning optical system 5 in the processing head 52.
6 shows a schematic perspective configuration of FIG. FIG. 3 shows a schematic configuration of the processing head 52 viewed from the side.

In FIG. 2, the scanning optical system 56 includes an optical surface plate 120, on which the parabolic mirror 1 is mounted.
22 is fixed. As shown in FIG. 3, the laser beam L introduced into the processing head 52 is
After being reflected once, the light is once focused, then spread, and simultaneously moved in the arrow P direction or the arrow Q direction by the focus adjustment motor 103, and is sequentially reflected by the focus adjustment mirrors 124 and 126, which are plane mirrors, respectively. The optical path is changed, and the optical path is introduced to the elliptical mirror 128.

The laser beam L introduced into the elliptical mirror 128 is reflected by the elliptical mirror 128, starts to converge again, and is rotated by the X-axis motor 101 about the X-axis 129 in the direction of the arrow. After being reflected by an X-axis scanning mirror 131 which is a mirror, the Y-axis motor 102
The optical surface plate 1 is reflected by a Y-axis scanning mirror 132 which is a plane mirror which is turned around a shaft 130 in an arrow direction.
The light is emitted from the processing head 52 through the opening 134 of the workpiece 20 and is focused at the processing point TCP on the workpiece 12. Focus adjusting mirror 12 so that the processing point TCP becomes the focus
The positions of 4 and 126 are adjusted by the focus adjustment motor 103. In the processing head 52 of this embodiment, Y
The focal length adjustment range from the axis scanning mirror 132 to the processing point TCP is about 50 cm to 130 cm (for example, see Japanese Patent Application Laid-Open No. Hei 9-192868 filed by the present applicant).

At the position shown in FIG. 3, when the Y-axis scanning mirror 132 is rotated, the processing point TCP moves substantially in the depth direction on the paper, and when the X-axis scanning mirror 131 is rotated, The processing point TCP moves in a substantially left-right direction substantially parallel to the paper surface. At the time of this scanning, at the same time, the processing point TCP which is the focal point on the processing surface of the workpiece
The positions of the focusing mirrors 124 and 126 are adjusted.

FIG. 4 is a block diagram showing an electrical configuration for a scanning / focus adjustment mechanism for scanning the laser beam L and adjusting the focus. The interface 60 connected to the bus 24 of the robot controller 16 includes D / A converters 81 to 83, an X-axis amplifier 91 and a Y-axis amplifier 92 which are servo amplifiers respectively connected to the output side, and a focus adjustment. Amplifier 93 is included. Outputs of the amplifiers 91 to 93 are supplied to an X-axis motor 101, a Y-axis motor 102, and a focus adjustment motor 103, which are servo motors constituting the optical system drive motor 58, respectively. Motor 101
The operations of the X-axis scanning mirror 131, the Y-axis scanning mirror 132, and the focus adjustment mirrors 124 and 126, which constitute the scanning optical system 56, are controlled by to 103.

Next, the operation of the above embodiment will be described.
This will be described in detail with reference to the flowcharts shown in FIGS.
5 is a flowchart for explaining a teaching operation mode, FIG. 6 is a flowchart for explaining a teaching operation confirmation mode, and FIG. 7 is a flowchart for explaining an actual welding operation. Unless otherwise noted, the controlling entity is CP
Although it is U22, since it becomes complicated, it is referred as necessary.

First, a description will be given with reference to FIG. In the off state of the laser oscillator 50, when the teaching operation mode changeover switch 42B among the operation mode changeover switches 42 is operated and turned on by the operator, it is recognized that the teaching operation mode has been selected (step S).
1). When this teaching operation mode is selected, the laser pointer 62 is turned on in the continuous light emission mode via the interface 68 and the pointer control circuit 64 (step S2), and the rod 66 is extended in the direction of arrow D to move the laser pointer 62. It is arranged on the optical path (optical axis) (step S3). As a result, the workpiece 12 is irradiated with the luminescent spot of the processing point indicating laser light Lp, which is a low-output visible laser light, as the processing point TCP.

The operator operates the teaching box 38 while watching the processing point TCP, moves the processing point TCP, and teaches the processing location (welding location), so that the teaching data as working data is stored in the hard disk drive 28. Is performed (step S4). For example, as shown in the operation locus diagram of the processing point TCP in FIG. 8, when a solid line drawn in the workpiece 12 is to be welded by linear interpolation,
While moving the processing point TCP, which is the luminescent point of the processing point instruction laser light Lp, each of the trajectory points W1, W
The positions of W2, W3, and W4 are sequentially taught using the teaching box 38, and the welding speed and the moving speed are designated by the operation code (mov) at each of the teaching points O, W1 to W4.

FIG. 9 shows teaching data 150 corresponding to the operation locus diagram of FIG. As can be seen from FIG. 9, at the origin O, the moving speed (SP
The percentage of D) is 100%, and the operation code (mov)
Is a PTP-ARV meaning fast-forwarding when not processing
(Point To Point arrive). Thus, the X-axis scanning is performed such that the region from the final trajectory point (final processing point) W4 to the origin O is a non-processing portion (indicated by a dotted line in FIG. 8), and the moving speed is rapidly advanced at the maximum speed. Mirror 131
To the Y-axis scanning mirror 132. Next, from the origin O to the first trajectory point (processing point) W1, teaching is also performed at the maximum speed of the non-processing portion at the rapid traverse. Next, an operation code (mov) LINW-ARV (Linear weld arri) meaning welding from a locus point (machining point) W1 to a locus point (machining point) W2 by a linear interpolation.
ve) and teaching at a welding movement speed of 90 mm / s. Hereinafter, between the trajectory points (processing points) W2 and W3, the workpiece is moved at a rapid traverse relating to the non-machining part, and between the trajectory points (processing points) W3 and W4, the workpiece is moved at a welding moving speed of 100 mm / s relating to the processing part. Taught to be. In practice, between the trajectory points (working points) W1 and W2 and between the trajectory points (working points) W3 and W4, the focus adjustment mirrors 124 and 126 are used to adjust the focal length. The operation (data) of the motor 103 is taught.

After the teaching is completed, the operation mode changeover switch 42A
Is turned on and the operation mode is turned off, so that the laser pointer 62 in which the laser beam Lp is in the non-emission state is pointed by the arrow U.
It is retracted in the direction and returns to the original position (step S5).

Next, the teaching confirmation operation will be described with reference to FIG. First, the operation mode changeover switch 42
C is turned on, and a teaching operation confirmation mode for confirming the suitability of the teaching data 150 created in the teaching operation mode is selected (step S11).

As a result, the laser pointer 62 is moved on the optical axis (step S12). When the teaching operation check mode is selected, the switching position of the irradiation mode switch 43 is checked, and the irradiation mode A or the irradiation mode B is selected (step S13).

As described above, when the irradiation mode A is selected, the irradiation is continuously performed in the processing portion, and the laser pointer 62 is controlled so that the irradiation is not performed in the non-processing portion (step S14), and the irradiation mode B is selected. If so, the laser pointer 62 is controlled such that continuous irradiation is performed in the processing part and blinking irradiation is performed in the non-processing part (step S15). Here, it is assumed that the irradiation mode A is selected. When the teaching operation confirmation mode is selected, when the X-axis scanning mirror 131 and the Y-axis scanning mirror 132 are stopped, in other words, when the processing point indicating laser light Lp is not scanned, the irradiation is not performed by default. However, it is also possible to switch to continuous irradiation.

Next, the propriety of the teaching data 150 is confirmed by a step feed (manual feed operation) or an automatic low-speed feed operation by an operation on a panel (not shown) of the teaching box 38 or the robot controller 16 (step S16). At this time, the operation code (mo
When v) is PTP-ARV, the scanning mirrors 131 and 132 are driven in a state where the processing point instruction laser light Lp does not emit light at the teaching speed. When the operation code (mov) is LINW-ARV, the laser pointer 62 starts simultaneously with the start of scanning, that is, the movement of the processing point TCP, which is the bright spot of the processing point instruction laser light Lp.
Are in a continuous irradiation state, and are brought into a non-irradiation state simultaneously with the end of the movement. In this case, based on the teaching data 150, the scanning is performed in the non-irradiation state between the origin O and the processing point W1, the scanning is performed in the irradiation state from the processing point W2 to the processing point W3, and the scanning is performed between the processing point W1 and the processing point W2. The scanning is performed in a non-irradiated state, the scanning is performed in an irradiated state from the processing point W3 to the processing point W4, and the scanning is performed in a non-irradiated state from the processing point W4 to the origin O.

As described above, when confirming the teaching operation, by confirming the trajectory of the irradiated portion of the processing point indicating laser light Lp, it is easily determined that the irradiated portion is the processed portion by the processing laser light L1. be able to.

When the confirmation and correction of the teaching data 150 is completed, the operation mode changeover switch 42A is turned on for the selection of the off operation and is turned off (step S17).

Next, the actual welding operation will be described with reference to FIG. When the welding operation mode switch 42D is turned on by the operator (step S
21) It is confirmed that the laser pointer 62 is not on the optical axis, and if it is on the optical axis, it is evacuated from the position on the optical axis to the original position (step S22).

Next, the laser shutter 54 is closed (step S23), and the laser oscillator 50 is turned on without outputting the processing laser beam L1 (step S24).

Next, an activation signal is supplied from the master controller 14 to the robot controller 16 (step S25).

Thus, a welding operation is performed on the workpiece 12 based on the teaching data 150 (step S26). That is, the operation code (mov) is PT
In the case of P-ARV, the scanning mirrors 131 and 132 are driven at the teaching speed with the laser shutter 54 closed. On the other hand, the operation code (m
When ov) is LINW-ARV, the laser shutter 54 is opened immediately after the start of scanning, that is, immediately after the start of movement from the processing point TCP, welding is performed by the laser beam L1, and the laser shutter 54 is closed at the end point of welding scanning. (Step S7). By operating the laser shutter 54 and the processing head 52 in this manner, a processing part (welding part) indicated by a solid line on the workpiece 12 shown in FIG.
Then, only the scanning operation of the scanning mirrors 131 and 132 is performed in the non-processed portion (non-welded portion) indicated by the dotted line.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0046]

As described above, according to the present invention, when the teaching operation of the laser processing apparatus is confirmed, the irradiation mode on the workpiece by the laser light for designating the processing point is
It is changed between the processed part and the non-processed part of the workpiece.

Therefore, at the time of confirming the teaching operation, by confirming the irradiation mode of the processing point indicating laser light on the workpiece, it is possible to quickly and clearly and simply determine whether or not the processing portion is processed by the processing laser light. You can judge.

When confirming the teaching operation,
By confirming the irradiation mode of the processing point indicating laser light on the workpiece, it is possible to clearly distinguish the irradiation for processing movement.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a production line to which an embodiment of the present invention is applied.

FIG. 2 is a perspective view showing a schematic configuration of a scanning optical system in the processing head.

FIG. 3 is a partial side sectional view schematically showing a configuration of a processing head.

FIG. 4 is a block diagram showing an electrical configuration for a scanning / focusing mechanism for adjusting a focus by scanning a laser beam.

FIG. 5 is a flowchart illustrating a teaching operation mode for creating teaching data;

FIG. 6 is a flowchart for explaining a teaching operation confirmation mode for confirming whether or not the created teaching data is appropriate;

FIG. 7 is a flowchart for explaining a welding operation mode;

FIG. 8 is a diagram showing a movement locus of a processing point.

9 is a table showing teaching data corresponding to a movement locus of a processing point in the example of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Production line 12 ... Workpiece 14 ... Master controller 16 ... Robot controller 18 ... Welding robot 20 ... Laser control panel 22 ... CPU 38 ... Teaching box 42, 42A-42D ... Operation mode changeover switch 43, 43A, 43B ... Irradiation Style changeover switch 50 Laser oscillator 52 Processing head 54 Laser shutter 56 Scanning optical system 58 Optical system drive motor 62 Laser pointer 120 Optical platen 122 Parabolic mirror 124, 126 Mirror for focus adjustment 128 ... elliptical mirror 131 ... X-axis scanning mirror 132 ... Y-axis scanning mirror 150 ... teaching data L1 ... laser light for welding Lp ... laser light for processing point indication TCP ... processing point

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiharu Sakai 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (56) References JP-A-54-61397 (JP, A) JP-A-63 −242480 (JP, A) Japanese Utility Model 2-65493 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 26/00 B23K 26/04 B25J 9/22 H01S 3/00

Claims (4)

(57) [Claims] An irradiation control of a processing point indicating laser beam in a laser processing apparatus capable of switching and emitting a processing laser beam and a processing point indicating laser beam indicating a processing point on the same optical axis. A method, wherein at the time of confirming a teaching operation of the laser processing apparatus, an irradiation mode for the workpiece by the processing point instruction laser light is changed between a processing part and a non-processing part of the workpiece. An irradiation control method of a laser beam for indicating a processing point in a laser processing apparatus. 2. An irradiation control of a processing point indicating laser beam in a laser processing apparatus capable of switching and outputting a processing laser beam and a processing point indicating laser beam indicating a processing point on the same optical axis. A method, wherein during the teaching operation of the laser processing apparatus,
The workpiece is continuously irradiated with the processing point instruction laser light, and when the teaching operation of the laser processing apparatus is confirmed, the irradiation mode of the processing point instruction laser light with respect to the workpiece is determined by the processing method. Irradiating differently in the processing part and the non-processing part of the object, at the time of processing the workpiece by the processing laser light,
A method for controlling the irradiation of a laser beam for processing point indication in a laser processing apparatus, wherein the laser beam is controlled so as not to be irradiated with the laser beam for processing point indication. 3. The method according to claim 1, wherein when the teaching operation of the laser processing apparatus is confirmed, the irradiation mode of the laser beam for designating the processing point is set to continuous irradiation on a processing portion of the workpiece. Laser processing characterized by continuously irradiating a workpiece and controlling the irradiation mode of the processing point indicating laser beam to non-irradiation on a non-processing portion of the workpiece so as not to irradiate the workpiece. An irradiation control method of a laser beam for indicating a processing point in an apparatus. 4. The method according to claim 1, wherein when the teaching operation of the laser processing apparatus is confirmed, the irradiation mode of the processing point indicating laser light is set to be continuous irradiation on a processing portion of the workpiece. Irradiating the workpiece continuously, on the non-processed part of the workpiece, controlling the irradiation mode of the laser light for processing point indication as a flashing irradiation to irradiate the workpiece with the flashing laser light. A method for controlling irradiation of a laser beam for indicating a processing point in a laser processing apparatus.