JP6299111B2 - Laser processing equipment - Google Patents

Description

  The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus including an observation optical system for observing a workpiece.

  Conventionally, a laser processing apparatus including an observation optical system including a camera, a lens, and the like for positioning a workpiece to be processed and confirming a processing state of the workpiece has been widespread.

  Some laser processing apparatuses equipped with an observation optical system, for example, observe a workpiece from the same direction as the optical axis of the processing optical system (hereinafter referred to as the processing optical axis) (see, for example, Patent Document 1), processing There is one that observes a workpiece from a direction different from the optical axis (see, for example, Patent Documents 2 and 3). Among laser processing apparatuses that observe a workpiece from a direction different from the machining optical axis, there are those that observe the workpiece from directly above (for example, see Patent Document 2), and those that observe the workpiece from an obliquely upward direction. (For example, refer to Patent Document 3).

  FIG. 1 schematically shows a configuration example of an optical system of a laser marker 1 which is a kind of laser processing apparatus that observes a workpiece from the same direction as the processing optical axis. The laser head 11 of the laser marker 1 includes a laser oscillator 21, a 3D optical system 22 that is a focus adjustment mechanism, a processing optical system including a dichroic mirror 23 and a galvanometer mirror 24, and an observation optical system 25.

  Laser light Lp emitted from the laser oscillator 21 is emitted from the laser head 11 via the 3D optical system 22, the dichroic mirror 23, and the galvanometer mirror 24, and is applied to the processing surface S. At this time, the laser beam Lp is scanned by the galvanometer mirror 24 in the biaxial directions of the X axis and the Y axis on the processing surface S.

  The observation optical system 25 can photograph the processed surface S via the mirror 23 and the galvanometer mirror 24. Further, the optical axis after the mirror 23 of the observation optical system 25 coincides with the processing optical axis. Thereby, the optical axis of the observation optical system 25 can be directed to an arbitrary position in the processing area where the laser beam Lp can be scanned by the galvanometer mirror 24.

  FIG. 2 schematically shows a configuration example of an optical system of a laser marker 31 which is a kind of laser processing apparatus for observing a workpiece from directly above. The laser beam Lp emitted from the laser head 41 is scanned on the processing surface S in the two axial directions of the X axis and the Y axis by the galvanometer mirror 51 in the laser head 41.

  An observation optical system 42 including a camera is provided beside the laser head 41 so that the optical axis is perpendicular to the processing surface S. Therefore, the observation optical system 42 can photograph the processed surface S from directly above. Further, by exchanging the lenses included in the observation optical system 42, it is possible to photograph the processing area at a desired magnification.

  FIG. 3 schematically shows a configuration example of an optical system of a laser marker 61 which is a kind of laser processing apparatus for observing a workpiece from an obliquely upward direction. In the figure, the same reference numerals are assigned to portions corresponding to the laser marker 31 of FIG.

  In the laser marker 61, the observation optical system 42 is provided beside the laser head 41 so that the optical axis is inclined with respect to the processing surface S. Therefore, the observation optical system 42 can directly photograph the processing area by the laser light Lp.

JP 2004-148379 A Japanese Patent Laid-Open No. 11-156666 JP 2012-143785 A

  However, as shown in FIG. 4, in the laser marker 1, the focused surface F of the observation optical system 25 is a curved surface, so that focusing can be performed only near the center of the processing area. In addition, a small mirror that can be driven at high speed is used as the galvanometer mirror 24, but the observation optical system 25 photographs a processed surface S through this small mirror, so that a large area can be photographed at a time. Can not. Therefore, with the laser marker 1, it is difficult to observe a wide range of the processing area with a clear image.

  Further, in the laser marker 31, since the processing area cannot be directly photographed by the observation optical system 42, it is necessary to move the workpiece during observation and during processing, and the control becomes complicated.

  Further, in the laser marker 61, since the imaging angle of the observation optical system 42 with respect to the processing surface S is large, it is difficult to focus on the entire imaging range, and the captured image is likely to be blurred or distorted. Observation may be difficult.

  Further, in the laser marker 31 and the laser marker 61, the observation optical system 42 is provided on the side of the laser head 41, thereby increasing the size of the apparatus and increasing the installation area (footprint).

  Therefore, in the present invention, it is possible to observe a wide range of the processing area by laser light while suppressing an increase in the installation area of the apparatus.

The laser processing apparatus of the present invention emits a laser beam for processing a workpiece to be processed, and includes a laser head including a scanning head for scanning the laser beam on a processing surface of the workpiece. An observation optical system comprising: a camera; a lens that forms an image of the processed surface on an image sensor of the camera; and a mirror that reflects light from the processed surface and enters the lens . An image processing unit that performs image processing of an observation image that is an image photographed by the camera; and a processing control unit that controls processing of the workpiece based on a result of image processing of the observation image; system is provided between the working surface and the scanning unit in the height direction, the image processing unit, centers of the imaging range of the camera processing area by the laser beam Based on the amount of deviation between the space used for the observation image, the center is restricted to a region coincides with the center of the working area.

In the laser processing apparatus of the present invention , based on the amount of deviation between the center of the processing area by the laser beam and the center of the shooting range of the camera, the region used by the observation image is centered on the center of the processing area. Limited to matching areas.

Therefore, it is possible to observe a wide range of the processing area by the laser beam while suppressing an increase in the installation area of the apparatus. In addition, workpiece processing control can be performed using an observation image obtained by photographing a wide range of the processing area. Furthermore, the center of the processing area and the observation area can be matched without performing mechanical adjustment.
The image processing unit and the processing control unit are realized by a processor such as a CPU, for example.

  This observation optical system can be arranged below the bottom surface of the laser head.

  Thereby, an observation optical system can be provided as a separate unit from the laser head.

  This mirror can be disposed between the lenses in the image in which the laser beam and the starting point are set.

  Thereby, a mirror can be reduced in size or an imaging range can be enlarged.

  This laser beam can pass between the lens and the mirror.

  Thereby, the restriction | limiting of the size of a lens can be made small. Moreover, it becomes easy to install a mirror so as not to block the laser beam. Furthermore, it becomes possible to photograph the workpiece from a direction closer to the vertical.

  The camera, the lens, and the mirror can be installed so that the processing surface, the main surface of the lens, and the imaging surface of the imaging device intersect substantially in a straight line.

  Thereby, a clear observation image without distortion and blur can be obtained.

  The laser processing apparatus further includes an illuminating device that illuminates the processing surface from an obliquely upward direction, and the illuminating device is configured so that the specularly reflected light of the illuminating light on the surface on which the observation optical system is in focus It can be installed to coincide with the axis.

  This makes it possible to observe the workpiece using only regular reflection light.

  This lens can be a telecentric lens.

  Thereby, an observation image without trapezoidal distortion can be obtained.

  The processing control unit can set the processing position based on the result of the image processing of the observation image.

  As a result, the processing position can be easily and accurately determined.

  The image processing unit can determine whether or not to perform the processing based on the result of the image processing of the observation image.

  Thereby, for example, when the workpiece is not installed or the workpiece is not in a desired state, the machining can be stopped.

  The image processing unit can inspect the processing state of the workpiece based on the result of the image processing of the observation image obtained by photographing the processed workpiece.

  Thereby, the processing state of the workpiece can be inspected with high accuracy.

  This image processing unit can correct the trapezoidal distortion of the observation image.

  Thereby, an observation image without trapezoidal distortion can be obtained.

  The image processing unit can invert the observation image in the vertical direction.

  As a result, it is possible to observe the image of the work that is turned upside down by the mirror in the correct direction.

  The laser processing apparatus is further provided with a light source that emits predetermined measurement light from an oblique direction toward the center of the processing area by the laser light on the in-focus surface of the observation optical system, and the image processing unit The irradiation position of the measurement light in the observation image obtained by photographing the irradiated processed surface is detected, and the processing control unit controls the focus of the processing optical system that emits the laser light based on the irradiation position of the measurement light in the observation image. The position can be adjusted.

  Thereby, the processing height of a laser processing apparatus can be adjusted easily and appropriately.

  The laser processing apparatus is further provided with a light source that irradiates the processing surface with predetermined measurement light via a scanning unit, and the image processing unit is configured to measure the measurement light in the observation image obtained by photographing the processing surface irradiated with the measurement light. The irradiation position is detected, and the processing control unit can adjust the focus position of the processing optical system that emits the laser light based on the irradiation position of the measurement light in the observation image.

  Thereby, the processing height of a laser processing apparatus can be adjusted easily and appropriately.

  ADVANTAGE OF THE INVENTION According to this invention, the wide range of the processing area by a laser beam can be observed, suppressing the increase in the installation area of an apparatus.

It is a figure which shows typically the 1st structural example of the optical system of the conventional laser marker. It is a figure which shows typically the 2nd structural example of the optical system of the conventional laser marker. It is a figure which shows typically the 3rd structural example of the optical system of the conventional laser marker. It is a figure for demonstrating the problem of the conventional laser marker. It is a perspective view which shows the structure of the external appearance of the state which removed the laser shielding cover of 1st Embodiment of the laser marker to which this invention is applied. It is a perspective view which shows the structure of the external appearance of the state which attached the laser shielding cover of 1st Embodiment of the laser marker to which this invention is applied. It is a figure which shows typically the structural example of the optical system of 1st Embodiment of the laser marker to which this invention is applied. It is a figure for demonstrating the modification of the installation method of an observation optical system. It is a figure for demonstrating the modification of the installation method of an observation optical system. It is a block diagram which shows the structural example of the function of a control part. It is a flowchart for demonstrating 1st Embodiment of a process. It is a figure which shows the example of a process recipe. It is a figure which shows the 1st example of a registration pattern. It is a figure which shows the 1st example of an observation image. It is a figure which shows the example of the result of pattern matching. It is a figure which shows the example of a setting of a process position. It is a figure which shows the example of a process of a workpiece | work. It is a flowchart for demonstrating 2nd Embodiment of a process. It is a flowchart for demonstrating 3rd Embodiment of a process. It is a figure which shows the example of a workpiece | work. It is a figure which shows the example of a process recipe. It is a figure which shows the 2nd example of a registration pattern. It is a figure which shows the normal example of the process state of a workpiece | work. It is a figure which shows the abnormal example of the process state of a workpiece | work. It is a figure for demonstrating the 1st example of the correction method of the shift | offset | difference of the center of a process area and an observation area. It is a figure for demonstrating the 2nd example of the correction method of the shift | offset | difference of the center of a process area and an observation area. It is a figure for demonstrating the 1st example of the countermeasure with respect to the trapezoid distortion of an observation image. It is a figure for demonstrating the 2nd example of the countermeasure with respect to the trapezoid distortion of an observation image. It is a figure for demonstrating the inversion process of an observation image. It is a figure for demonstrating the 1st example of the adjustment method of process height. It is a figure for demonstrating the 1st example of the adjustment method of process height. It is a figure for demonstrating the 2nd example of the adjustment method of process height. It is a figure for demonstrating the 2nd example of the adjustment method of process height. It is a figure for demonstrating the comparison with the former in the 2nd example of the adjustment method of process height. It is a figure which shows typically the structural example of the optical system of 2nd Embodiment of the laser marker to which this invention is applied. It is a figure which shows typically the structural example of the optical system of 3rd Embodiment of the laser marker to which this invention is applied. It is a figure which shows typically the structural example of the optical system of 4th Embodiment of the laser marker to which this invention is applied.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. First Embodiment 2. FIG. Second embodiment (example in which epi-illumination is provided in the first embodiment)
3. Third Embodiment (Example in which processing laser beam passes between lens and mirror)
4). Fourth embodiment (example in which epi-illumination is provided in the third embodiment)
5. Modified example

<1. First Embodiment>
First, a first embodiment of the present invention will be described with reference to FIGS.

{Configuration example of laser marker 101}
First, a configuration example of the laser marker 101 which is the first embodiment of the laser processing apparatus to which the present invention is applied will be described with reference to FIGS. FIG. 5 shows an example of the external configuration of the laser marker 101 with the laser shielding cover 114 removed, and FIG. 6 shows an example of the external configuration of the laser marker 101 with the laser shielding cover 114 attached. FIG. 7 schematically shows a configuration example of the optical system of the laser marker 101. In the following, each drawing of the optical system including FIG. 7 is a schematic diagram, and some parts that are not required to be very accurate may not be optically correct.

  Hereinafter, the left side of FIG. 5 is the front side of the laser marker 101 and the right side is the rear side of the laser marker 101. In addition, hereinafter, the side where the side is visible in FIG. 5 is the right side of the laser marker 101, and the opposite side is the left side of the laser marker 101. Further, hereinafter, the left-right direction of the laser marker 101 is defined as the X-axis direction, the front-rear direction is defined as the Y-axis direction, and the vertical direction is defined as the Z-axis direction.

  The laser marker 101 is a laser processing apparatus that performs marking on the surface of a workpiece to be processed using laser light. The laser marker 101 is configured to include a laser head 111, an attachment 112, and attachments 113FR to 113BL (however, the attachment 113BL is not shown).

  The laser head 111 has a box shape, and its size is, for example, width 140 mm × depth 415 mm × height 220 mm. The depth including the fan behind the laser head 111 is, for example, 450 mm. As will be described later, the laser head 111 is provided with a processing optical system for irradiating a workpiece, which is a processing target, with processing laser light (hereinafter referred to as processing laser light).

  The attachment 112 is attached behind the bottom surface of the laser head 111. As will be described later, the attachment 112 accommodates an observation optical system for observing the processing area of the laser marker 101.

  Attachments 113FR to 113BL are attached near the four corners of the bottom surface of the laser head 111 and constitute legs for supporting the laser head 111. Further, the attachments 113FR to 113BL secure a space for attaching the attachment 112 below the laser head 111.

  Further, as shown in FIG. 6, the laser shielding cover 114 is attached to the lower part of the laser head 111 so as to surround the periphery of the attachment 112 and the attachments 113FR to 113BL. The laser shielding cover 114 prevents the processing laser light emitted from the laser head 111 from leaking to the surroundings.

  As shown in FIG. 7, the laser head 111 is provided with a laser oscillator 151, a light source 152, a dichroic mirror 153, a 3D optical system 154, a mirror 155, a galvano mirror 156, and a light source 157. Among them, the laser oscillator 151, the dichroic mirror 153, the 3D optical system 154, the mirror 155, and the galvanometer mirror 156 constitute a processing optical system.

  The attachment 112 houses an observation optical system including a camera 161, a lens 162, and a mirror 163. Therefore, the observation optical system is disposed below the bottom surface of the laser head 111 and between the galvano mirror 156 and the processing surface S in the height direction.

  The laser oscillator 151 emits a processing laser beam for processing a workpiece. Note that the type of the laser oscillator 151 is not particularly limited, and an arbitrary one can be adopted.

  The machining laser light passes through the dichroic mirror 153 and the 3D optical system 154, is reflected by the mirror 163 and the galvano mirror 156, and is irradiated onto the machining surface S of the workpiece. At this time, the focus position in the Z-axis direction of the machining optical system (the condensing position of the machining laser light in the Z-axis direction) can be adjusted by the 3D optical system 154 that is a focus adjustment mechanism. In addition, as shown in FIG. 7, the processing laser light can be scanned in the X axis and Y axis directions on the processing surface S by the galvanometer mirror 156.

  Hereinafter, a range that can be processed by scanning the processing laser light is referred to as a processing area. In addition, when the machining laser beam is emitted vertically downward from the laser head 111, the position irradiated with the machining laser beam is defined as the center of the machining area, and is hereinafter referred to as the machining center.

  The light source 152 emits visible laser light (hereinafter referred to as a guide laser). The guide laser light passes through the dichroic mirror 153 and the 3D optical system 154, is reflected by the mirror 163 and the galvano mirror 156, and is irradiated onto the processing surface S of the workpiece. Similarly to the machining laser beam, the guide laser also adjusts the condensing position in the Z-axis direction by the 3D optical system 154, or scans the machining surface S in the X-axis and Y-axis directions by the galvanometer mirror 156. be able to.

  The guide laser is used for confirming the processing shape. That is, the image of the processed shape can be visually confirmed by scanning the guide laser on the processed surface S in the same manner as at the time of processing before processing with the processing laser light.

  Further, as will be described later, the guide laser measures the focus position (processing laser beam condensing position) of the processing optical system, and the processing position (hereinafter also referred to as processing height) in the Z-axis direction (height direction). It can also be used as a measurement light for adjusting.

  The light source 157 emits visible laser light (hereinafter referred to as a focus pointer). Note that the focus pointer is adjusted so as to pass through a processing center on a surface (hereinafter referred to as an observation system focal plane) on which the observation optical system is focused from an oblique direction. As will be described later, the focus pointer is used as measurement light for measuring the focus position of the processing optical system (condensing position of the processing laser light) and adjusting the processing height, as with the guide laser.

  The camera 161, the lens 162, and the mirror 163 capture an image for observing the processed surface S (hereinafter referred to as an observation image). The user can observe the state of the processing area and the like from this observation image.

  The camera 161 is installed in the horizontal direction so that the imaging surface of an imaging element (not shown) is perpendicular to the processing surface S. The lens 162 is installed so that the optical axis coincides with the optical axis of the camera 161. The mirror 163 is installed such that the reflecting surface is directed obliquely downward with respect to the main surface of the lens 162.

  The light from the processing surface S is reflected by the mirror 163, enters the lens 162, and forms an image on the imaging surface of the imaging element of the camera 161 by the lens 162. Then, an image of the processed surface S is taken by the camera 161. Further, by adjusting the angle of the mirror 163, the shooting range of the camera 161 (hereinafter also referred to as an observation area) and the angle at which the processed surface S is shot (hereinafter referred to as a shooting angle) are adjusted.

  For example, the angle of the mirror 163 may be manually or electrically mechanically adjusted with the attachment 112 attached to the laser head 111.

  Therefore, according to the laser marker 101, the observation magnification of the processing surface S can be freely set by exchanging the lens 162. Further, since the processing surface S is directly photographed without using the galvanometer mirror 156 as in the laser marker 1 in FIG. 1, light vignetting by the galvanometer mirror 156 does not occur. Therefore, a wide range including the entire processing area can be photographed and observed with the camera 161.

  Further, by providing the mirror 163, it is not necessary to point the camera 161 toward the processing surface S in order to photograph the processing surface S, and the camera 161 can be installed so as to face in the horizontal direction. As a result, the attachment 112 that houses the observation optical system can be attached to the bottom surface of the laser head 111. As a result, the apparatus can be miniaturized, and an increase in footprint due to the provision of an observation optical system such as the laser marker 31 in FIG. 2 or the laser marker 61 in FIG. 3 can be prevented.

  Furthermore, by providing the mirror 163, it is possible to set the photographing angle in a direction perpendicular to the processing surface S as compared with the laser marker 61 of FIG. Thereby, the angle between the observation system focal plane and the processed surface S can be reduced, and the entire observation area (imaging range) can be easily focused. As a result, it is possible to suppress the occurrence of blur and distortion in the observed image.

{Variation of installation direction of camera 161 and lens 162}
The installation direction of the camera 161 and the lens 162 is not necessarily limited to the example of FIG. For example, by installing the camera 161 so as to face obliquely upward, the angle of the mirror 163 can be made more horizontal. As a result, the shooting angle can be made closer to the vertical, making it easier to focus on the entire observation area (shooting range).

  Further, for example, as shown in FIG. 8, the imaging surface of the imaging device 161 a of the camera 161, the main surface 162 a of the lens 162, and the processing surface S substantially intersect in a straight line so that the shine proof condition is satisfied. In addition, a camera 161, a lens 162, and a mirror 163 may be installed. That is, when the optical path from the processing surface S to the camera 161 is simulated and extended without being bent by the mirror 163, the imaging surface of the imaging device 161a of the camera 161, the main surface 162a of the lens 162, and the processing surface S are straight. You may make it install the camera 161, the lens 162, and the mirror 163 so that it may cross | intersect on a line. For example, as shown in FIG. 9, this can be realized by tilting the main surface of the lens 162 so as to face the upper oblique direction and adjusting the angle.

  Thereby, it is possible to satisfactorily focus the observation optical system in all the areas in the observation area, and it is possible to obtain a clear observation image free from distortion and blur.

{Processing of laser marker 101}
Next, processing of the laser marker 101 will be described with reference to FIGS.

(Configuration example of the control unit 201)
FIG. 10 is a block diagram illustrating a configuration example of functions of the control unit 201 provided in the laser marker 101. The control unit 201 is configured by a processor such as a CPU (Central Processing Unit), for example. The control unit 201 may be provided in either the laser head 111 or the attachment 112, or may be provided in a distributed manner in the laser head 111 and the attachment 112.

  The control unit 201 is configured to include an imaging control unit 211, an image processing unit 212, and a processing control unit 213.

  The shooting control unit 211 controls shooting of an observation image by the camera 161.

  As will be described later, the image processing unit 212 performs various types of image processing on the observation image captured by the camera 161. Further, the image processing unit 212 outputs the result of the image processing to the outside as necessary.

  The processing control unit 213 controls the laser oscillator 151, the 3D optical system 154, the galvanometer mirror 156, and the like to control the processing of the workpiece by the laser head 111.

(First embodiment of processing)
Next, a first embodiment of the processing performed by the laser marker 101 will be described with reference to the flowchart of FIG.

  In step S1, the control unit 201 acquires a processing recipe input from the outside.

  Here, the processing recipe is information indicating the size and shape of a mark (for example, a character or a graphic) to be marked by the laser marker 101, and the processing position in the workpiece to be processed. FIG. 12 shows an example of a processing recipe in which a circular mark 301 is registered.

  In step S2, the control unit 201 acquires a registration pattern input from the outside. Here, the registered pattern is a pattern used for detecting a workpiece by pattern matching in the observation area. For example, an image of a workpiece before processing, an image (for example, an outline diagram) representing features of the workpiece before processing, or the like is given as a registered pattern.

  FIG. 13 shows an example of a pattern image 311 including a registered pattern 312. This pattern image 311 shows a square registered pattern 312.

  In step S <b> 3, the camera 161 shoots the processing area under the control of the shooting control unit 211. And the control part 201 acquires the observation image obtained as a result of imaging | photography. At this time, as described above, it is possible to obtain a high-quality observation image that includes the entire processing area or a wide range within the processing area and is less distorted and blurred.

  FIG. 14 shows an example of an observation image. In this observation image 321, two works, a work 322a and a work 322b, are shown.

  In step S4, the image processing unit 212 performs pattern matching. For example, the image processing unit 212 searches the observation image 321 in FIG. 14 for a pattern that matches the registered pattern 312 in FIG. For example, as illustrated in FIG. 15, the workpiece 322 a and the workpiece 322 b are detected from the observation image 321.

  Note that any method can be adopted for pattern matching performed by the image processing unit 212.

  In step S5, the machining control unit 213 sets a machining position. For example, the processing control unit 213 calculates the coordinates (processing coordinates) of the processing position in the workpiece 322a and the workpiece 322b detected in the observation image 321 based on the processing recipe. For example, when marking the center of the workpiece 322a and the workpiece 322b, as shown in FIG. 16, the coordinates of the center 331a of the pattern 322a and the center 331b of the pattern 322b in the observation image 321 are calculated as processing coordinates. And the process control part 213 converts the process coordinate in the observation image 321 into the coordinate in the process area of the laser marker 101, and sets the calculated | required coordinate to a process position.

  Here, the observation image 321 shows the entire processing area or a wide range within the processing area. Therefore, for example, it is possible to detect all the workpieces in the machining area using only one observation image 321 and set all the machining positions at one time.

  In step S <b> 6, the laser head 111 performs processing under the control of the processing control unit 213. That is, under the control of the processing control unit 213, the laser head 111 processes the mark indicated in the processing recipe at the processing position set in the process of step S5. For example, as shown in FIG. 17, the processing of the mark Ma and the mark Mb having the same shape as the mark 301 in FIG. 12 is performed at the center of the work 322a and the work 322b.

  Thereafter, the processing process ends.

  As described above, the laser marker 101 can quickly detect and mark a processing position by pattern matching using a high-quality observation image including the entire processing area or a wide range in the processing area. In addition, the desired position of the workpiece can be marked with high accuracy regardless of the installation position and installation direction of the workpiece.

(Second Embodiment of Processing)
Next, a second embodiment of the processing executed by the laser marker 101 will be described with reference to the flowchart of FIG.

  In steps S31 to S34, processing similar to that in steps S1 to S4 of FIG. 11 described above is executed.

  In step S <b> 35, the image processing unit 212 determines whether or not the degree of coincidence is equal to or greater than a threshold based on the result of pattern matching. That is, the image processing unit 212 calculates the degree of coincidence between the pattern detected in the observation image in the process of step S34 and the registered pattern, and determines whether the degree of coincidence is equal to or greater than a predetermined threshold. If it is determined that the degree of coincidence is equal to or greater than the threshold, the process proceeds to step S36.

  In steps S36 and S37, processing similar to that in steps S5 and S6 in FIG. 11 is executed, and the workpiece is processed.

  Thereafter, the processing process ends.

  On the other hand, if it is determined in step S35 that the degree of coincidence is less than the threshold, the process proceeds to step S38. This is the case, for example, when there is no work in the observation area or when the work is not in a desired state.

  In step S38, the image processing unit 212 outputs an abnormal signal. That is, the image processing unit 212 generates and outputs an abnormal signal indicating that the workpiece has not been processed normally. Then, for example, a notice that an abnormality has occurred in the machining of the workpiece is made by a method such as turning on a warning lamp provided outside the laser marker 101 based on the abnormality signal.

  Thereafter, the processing process ends.

  In this way, it is determined whether or not processing is to be performed based on the matching degree of pattern matching. Thus, for example, the presence or absence of a workpiece is determined, and machining is performed only when the workpiece is present, or whether or not the workpiece is in a desired state is determined and machining is performed only when the workpiece is in a desired state. can do.

(Third embodiment of processing)
Next, a third embodiment of the processing executed by the laser marker 101 will be described with reference to the flowchart of FIG. Hereinafter, a case where the square workpiece 351 shown in FIG. 20 is processed will be described.

  In step S61, a processing recipe is acquired in the same manner as in step S1 of FIG. Hereinafter, a case where the processing recipe shown in FIG. 21 is given will be described. A circular mark 361 is registered in the processing recipe of FIG.

  In step S62, the control unit 201 acquires a registration pattern input from the outside. The registered pattern obtained here is a pattern used for inspection of the machining state of the workpiece, unlike the registered pattern used in the first and second embodiments of the machining process. For example, an image of a workpiece after machining (after marking), an image (for example, an outline diagram) representing features of the workpiece after machining, or the like is given as a registered pattern.

  FIG. 22 shows an example of a pattern image 371 including a registered pattern 372. The pattern image 371 shows a registered pattern 372 in which the mark 361 in FIG. 21 is arranged at the center of the work 351 in FIG.

  In step S63, the laser head 111 performs processing under the control of the processing control unit 213. That is, the laser head 111 processes the mark indicated in the processing recipe at a predetermined position of the workpiece under the control of the processing control unit 213.

  In step S64, the processing area is photographed in the same manner as in step S3 of FIG. Thereby, the observation image containing the workpiece | work after a process is obtained.

  In step S65, pattern matching is performed in the same manner as in step S4 of FIG. In other words, the processing state of the workpiece is inspected using pattern matching. More specifically, it is inspected whether or not the machining state of the workpiece is in a state indicated by the registered pattern.

  In step S66, as in the process of step S35 of FIG. For example, in step S63, as shown in FIG. 23, when a mark Mc having the same shape as the mark 361 in FIG. 21 is marked at the approximate center of the work 351, the pattern composed of the work 351 and the mark Mc is shown in FIG. Is very close to the registered pattern 372. Therefore, in this case, it is determined that the degree of coincidence is equal to or greater than the threshold value, that is, it is determined that the processing state is normal, and the processing process ends.

  On the other hand, for example, as shown in FIG. 24, when the processing position of the mark Md is shifted from the center of the workpiece 351, the pattern made up of the workpiece 351 and the mark Md has a large difference from the registered pattern 372 in FIG. Accordingly, in this case, it is determined in step S66 that the degree of coincidence is less than the threshold value, that is, it is determined that the machining state is abnormal, and the process proceeds to step S67.

  In step S67, the image processing unit 212 outputs an abnormal signal. That is, the image processing unit 212 generates and outputs an abnormality signal indicating that the workpiece machining state is abnormal. Then, for example, a notice that an abnormality has occurred in the machining of the workpiece is made by a method such as turning on a warning lamp provided outside the laser marker 101 based on the abnormality signal.

  As described above, the laser marker 101 can inspect the processing state with high accuracy by pattern matching using a high-quality observation image including the entire processing area or a wide range in the processing area.

(Correction method for misalignment between center of processing area and observation area)
Next, with reference to FIG. 25 and FIG. 26, a method for correcting the misalignment between the processing area of the laser marker 101 and the center of the observation area will be described.

  When the attachment 112 is attached to the laser head 111, there may be a deviation between the center C1 of the processing area 401 and the center C2 of the observation area 402, as shown in the upper part of FIG. The size of the deviation (deviation amount) can be detected by, for example, the following method.

  For example, first, the laser head 111 performs processing on the center C <b> 1 of the processing area 401 under the control of the processing control unit 213. As a result, a machining point Me is formed at the center C1 of the machining area 401 as shown in the center of FIG.

  Next, the camera 161 captures an image of the processing area in which the processing point Me is formed under the control of the imaging control unit 211. Then, the image processing unit 212 detects the processing point Me in the observation image by an arbitrary method such as edge extraction or pattern matching. Further, the image processing unit 212 uses the deviation amounts ΔX and ΔY between the detected processing point Me and the center C2 of the observation image as a deviation amount between the center C1 of the processing area 401 and the center C2 of the observation area 402. To detect.

  The correction of the deviation can be mechanically corrected by adjusting the position of the observation area by adjusting the position of the camera 161 or the lens 162 or the angle of the mirror 163, for example. At this time, for example, the angle of the mirror 163 may be automatically adjusted based on the detected amount of deviation to correct the deviation.

  Also, as shown in FIG. 26, it is possible to correct the deviation by image processing. For example, the area used by the image processing unit 212 in the image in the observation area 402 (that is, the observation image) is limited to the area 403 where the center C3 coincides with the center C1 of the processing area 401. Specifically, for example, the image processing unit 212 cuts out the image in the region 403 from the observation image and outputs it to the subsequent stage. For example, when an image output from the image processing unit 212 is displayed, the center of the displayed image (that is, the observation area) apparently coincides with the center C1 of the processing area 401.

  Accordingly, it is possible to correct the deviation between the center of the processing area and the center of the observation area without adjusting the position and angle of the camera 161, the lens 162, or the mirror 163.

(Measures against trapezoidal distortion of observed images)
Next, a countermeasure against trapezoidal distortion of the observation image will be described with reference to FIGS. 27 and 28. FIG.

  In the laser marker 101, since the workpiece is photographed obliquely upward via the mirror 163, when the lens 162 is a non-telecentric lens, trapezoidal distortion occurs in the observed image as shown in the upper diagram of FIG. . That is, for example, when a rectangular workpiece is photographed, the width of the workpiece image 451 in the observation image becomes narrower as it goes up.

  On the other hand, it is conceivable to use a telecentric lens for the lens 162 first. As a result, as shown in the lower diagram of FIG. 27, the trapezoidal distortion does not appear in the work image 452 in the observation image, and the shape of the image 452 becomes rectangular.

  Note that a telecentric lens can also be employed in the laser marker 61 of FIG. However, the laser marker 101 has a smaller imaging angle with respect to the processed surface S and less trapezoidal distortion than the laser marker 61, and thus the effect of the telecentric lens is increased.

  Further, for example, the image processing unit 212 may perform image processing for removing the trapezoidal distortion on the observation image. For example, the image processing unit 212 uses the affine transformation defined by the following equations (1) and (2) to change the coordinates (x, y) of each pixel in the observation image to the coordinates (x ′, y ′). Convert.

x '= a * x + b * y + c (1)
y '= d * x + e * y + f (2)

  Note that a to f in the equations (1) and (2) are predetermined coefficients.

  Then, the image processing unit 212 uses the pixel values at the coordinates (x ′, y ′) after the change as the bilinear values using the pixel values of the four pixels around the coordinates (x ′, y ′) in the original observation image. Obtained by interpolation or the like, and generates a converted image.

  Thereby, without using an expensive telecentric lens, as shown in FIG. 28, an image 461 of a workpiece deformed into a rectangle can be obtained by removing trapezoidal distortion.

(Reversal processing of observation image)
In the laser marker 101, an image reflected by the mirror 163 is taken by the camera 161. For this reason, as shown in the upper diagram of FIG. 29, the workpiece image 471 in the observation image is inverted in the vertical direction as compared with the case where it is viewed from the photographing direction. Therefore, for example, as shown in the lower diagram of FIG. 29, the image processing unit 212 applies to the observation image so that the vertical direction coincides with the case where the work image 471 in the observation image is viewed from the photographing direction. An inversion process may be performed.

(Processing height adjustment method)
Next, a method for adjusting the processing height of the laser marker 101 will be described with reference to FIGS. 30 to 33.

  First, with reference to FIG. 30 and FIG. 31, the case where the processing height is adjusted using the focus pointer Lf emitted from the light source 157 will be described. Hereinafter, it is assumed that the processing surface S2 coincides with the observation system focal plane, the processing surface S1 is at a position higher than the processing surface S2, and the processing surface S3 is at a position lower than the processing surface S2. Further, the irradiation points of the focus pointer Lf on the processed surfaces S1, S2, and S3 are set as irradiation points Pf1, Pf2, and Pf3, respectively.

  FIG. 31 schematically shows an example of an observation image obtained by photographing the processed surfaces S1 to S3 irradiated with the focus pointer Lf with the camera 161. The left end is an observation image obtained by photographing the processed surface S1, the center is an observation image obtained by photographing the processed surface S2, and the right end is an observation image obtained by photographing the processed surface S3.

  In the observation image of the processing surface S2 that coincides with the observation system focal plane (just focused), the position of the irradiation point Pf2 is substantially the center in the vertical direction. On the other hand, in the observation image of the processing surface S1 that is higher than the processing surface S2, the position of the irradiation point Pf1 is below the center in the vertical direction. Then, the position of the irradiation point Pf1 in the observation image decreases in proportion to the distance of the processing surface S1 from the observation system focal plane. In the observation image of the processed surface S3 located at a position lower than the processed surface S2, the position of the irradiation point Pf3 is higher than the center in the vertical direction. Then, the position of the irradiation point Pf3 in the observation image increases in proportion to the distance of the processing surface S3 from the observation system focal plane.

  Accordingly, for example, the image processing unit 212 can detect the height of the processing surface relative to the observation system focal plane by detecting the vertical position of the irradiation point of the focus pointer Lf in the observation image. . Then, for example, the processing control unit 213 controls the 3D optical system 22 so that the focusing position of the processing laser light in the Z-axis direction (the focus position of the processing optical system) is adjusted to the detected processing surface height. Thus, the processing height can be adjusted appropriately.

  Next, with reference to FIG. 32 and FIG. 33, the case where the processing height is adjusted using the guide laser Lg emitted from the light source 152 will be described. Hereinafter, as shown in FIG. 32, the irradiation points of the guide laser Lg on the processed surfaces S1, S2, and S3 are referred to as irradiation points Pg1, Pg2, and Pg3, respectively. The positions of the processed surfaces S1, S2, and S3 are the same as those in FIG.

  FIG. 33 schematically shows an example of an observation image obtained by photographing the processed surfaces S1 to S3 irradiated with the guide laser Lg with the camera 161. The left end is an observation image obtained by photographing the processed surface S1, the center is an observation image obtained by photographing the processed surface S2, and the right end is an observation image obtained by photographing the processed surface S3.

  The position of the irradiation point of the guide laser Lg in the observation image with respect to the height of the processed surface shows the same tendency as the focus pointer Lf. That is, in the observation image of the processed surface S2 (just focused) that coincides with the observation system focal plane, the position of the irradiation point Pg2 is substantially the center in the vertical direction. On the other hand, in the observation image of the processed surface S1, the position of the irradiation point Pg1 decreases in proportion to the distance of the processed surface S1 from the observation system focal plane. In the observation image of the processed surface S3, the position of the irradiation point Pg3 increases in proportion to the distance of the processed surface S3 from the observation system focal plane.

  Therefore, as in the case where the focus pointer Lf is used, the image processing unit 212 detects the position of the irradiation point of the guide laser Lg in the observation image in the vertical direction, so that the processing surface with the observation system focal plane as a reference is detected. The height can be detected. Then, for example, the processing control unit 213 controls the 3D optical system 22 so that the focusing position of the processing laser light in the Z-axis direction (the focus position of the processing optical system) is adjusted to the detected processing surface height. Thus, the processing height can be adjusted appropriately.

  For example, in the laser marker 1 of FIG. 1, when it is attempted to detect the height of the processed surface using a guide laser, an image of the guide laser is observed through the galvanometer mirror 24. Therefore, as shown in FIG. 34, even if the height of the processed surface changes, the vertical position of the guide laser irradiation point in the observation image hardly changes. Therefore, in the laser marker 1, the machining height cannot be adjusted using only the guide laser. In the laser marker 1, for example, the processing height is adjusted based on whether or not the irradiation positions of the guide laser and the focus pointer match.

<2. Second Embodiment>
Next, with reference to FIG. 35, a second embodiment of the present invention will be described.

{Configuration example of laser marker 501}
FIG. 35 schematically shows a configuration example of an optical system of a laser marker 501 which is the second embodiment of the laser processing apparatus to which the present invention is applied. In the figure, parts corresponding to those of the laser marker 101 in FIG.

  The laser marker 501 is obtained by adding an installation jig 511 and an illumination device 512 to the laser marker 101. The illumination device 512 is attached to the front of the bottom surface of the laser head 111 via the installation jig 511. That is, the illumination device 512 is attached to the side opposite to the mirror 622 with reference to the emission position of the machining laser light from the laser head 111. The installation jig 511 and the lighting device 512 may be housed in the same attachment as the camera 161, the lens 162, and the mirror 163, or in a different attachment.

  The illumination device 512 is used as epi-illumination that irradiates the processing surface S with illumination light Le1 from an oblique direction. In addition, when the processed surface S matches the observation system focal plane, the illuminating device so that the central axis of the regular reflection light on the processed surface S of the illumination light Le1 from the illumination device 512 matches the optical axis of the observation optical system. The position and inclination 512 (the emission direction of the illumination light Le1) are adjusted.

  As a result, the workpiece can be observed using only the regular reflection light. For example, by observing the regular reflection light from the processed surface S of the workpiece, it is determined whether the surface of the workpiece is a mirror surface or a rough surface. It becomes possible.

  In the case of the laser marker 1 in FIG. 1, the illumination light reflected by the processing surface S enters the observation optical system 25 via the galvanometer mirror 24. Therefore, in the laser marker 1, the regular reflection light from the processed surface S does not necessarily enter the observation optical system 25, and reflected light other than the regular reflection light enters the observation optical system 25. Therefore, for example, the surface of the workpiece cannot be determined by the method described above.

  In addition, since the illumination device 512 is installed on the bottom surface of the laser head 111, an increase in footprint can be prevented.

<3. Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIG.

{Configuration example of laser marker 601}
FIG. 36 schematically shows a configuration example of an optical system of a laser marker 601 which is the third embodiment of the laser processing apparatus to which the present invention is applied. In the figure, parts corresponding to those of the laser marker 101 in FIG. Further, illustration of the light source 157 in the laser head 111 is omitted.

  The laser marker 601 is different from the laser marker 101 in that an attachment 611 is attached to the bottom surface of the laser head 111 instead of the attachment 112.

  The attachment 611 is configured to include a camera 161, a lens 621, and a mirror 622. In this example, the mirror 622 is housed in the same attachment 611 as the camera 161 and the lens 621. For example, the mirror 622 is directly housed in a separate attachment or not in the attachment. It is also possible to attach to the bottom surface of 111.

  In the laser marker 601, the lens 621 and the mirror 622 are installed so that the processing laser light passes between the lens 621 and the mirror 622. As a result, the space between the camera 161 and the mirror 622 is expanded, and the restriction on the lens size is reduced. Therefore, for example, as shown in FIG. 36, a lens 621 larger than the lens 162 of the laser marker 101 can be installed.

  Thereby, an improvement in image quality such as clearer observation images can be realized. Further, with the improvement of the image quality of the observation image, more accurate image processing can be performed. For example, the processing position positioning accuracy can be improved.

  Further, the mirror 622 can be installed in a direction closer to the vertical as compared with the mirror 163 of the laser marker 101. Therefore, it becomes easy to install the mirror 622 so as not to block the processing laser light.

  On the other hand, the mirror 163 of the laser marker 101 can be made smaller than the mirror 622 of the laser marker 601. Alternatively, when the sizes of the mirror 163 and the mirror 622 are the same, the laser marker 101 has a wider observation area and can capture a wider range.

<4. Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described with reference to FIG.

{Configuration example of laser marker 701}
FIG. 37 schematically shows a configuration example of an optical system of a laser marker 701 which is the fourth embodiment of the laser processing apparatus to which the present invention is applied. In the figure, parts corresponding to those of the laser marker 601 in FIG.

  As with the laser marker 501 in FIG. 35, the laser marker 701 enables the workpiece to be observed with specularly reflected light. Specifically, the laser marker 701 is different from the laser marker 601 in that an attachment 711 is attached to the bottom surface of the laser head 111 instead of the attachment 611. The attachment 711 is different from the attachment 611 in that a lens 721 is provided instead of the lens 621, and an installation jig 722 and a lighting device 723 are added.

  The illuminating device 723 is attached to the bottom surface of the laser head 111 via the installation jig 722 on the side opposite to the mirror 622 with reference to the emission position of the processing laser light from the laser head 111. Although it is possible to use the lens 621 in FIG. 36 instead of the lens 721, an example in which a lens 721 smaller than the lens 621 is provided is shown for easy understanding of the drawing. In this example, the mirror 622, the installation jig 722, and the illumination device 723 are stored in the same attachment 711 as the camera 161 and the lens 721. You may make it attach directly to the bottom face of the laser head 111, without storing in the.

  The illumination device 723 is used as epi-illumination that irradiates the processing surface S with illumination light Le2 from an oblique direction, similarly to the illumination device 512 of the laser marker 501 in FIG. In addition, when the processing surface S coincides with the observation system focal plane, the illumination device is configured such that the central axis of the regular reflection light on the processing surface S of the illumination light Le2 from the illumination device 723 coincides with the optical axis of the observation optical system. The position and inclination of 723 (the emission direction of the illumination light Le2) are adjusted.

  Thereby, similarly to the laser marker 501 in FIG. 35, the workpiece can be observed with the specularly reflected light. For example, by observing the specularly reflected light from the processing surface S of the workpiece, the surface of the workpiece is mirror-like or rough. It is possible to determine whether a surface is present.

  Further, since the illumination device 723 is installed on the bottom surface of the laser head 111, an increase in footprint can be prevented.

<5. Modification>
Hereinafter, modifications of the above-described embodiment of the present invention will be described.

  In the above description, an example in which the present invention is applied to a laser marker has been shown. However, the present invention is not limited to a laser marker having an observation optical system (for example, drilling, cutting, two-dimensional processing, three-dimensional processing). It is possible to apply to a device that performs processing, laser repair, and the like.

  In the above description, an example of detecting a workpiece in the observation area using pattern matching has been described. However, a predetermined pattern in the workpiece is detected, and a processing position is set based on the detected pattern. Is also possible. Furthermore, for example, it is possible to detect a workpiece or a pattern in the workpiece by using an image processing method other than pattern matching such as edge extraction or feature point extraction.

  Further, for example, part or all of the observation optical system may be provided in the laser head 111. However, also in this case, it is desirable to arrange an observation optical system between the galvanometer mirror 156 and the processing surface S in the height direction.

  Further, for example, the laser oscillator 151 may be provided outside the laser head 111.

  Further, for example, either or both of the light source 152 and the light source 157 of the laser head 111 can be omitted.

  Furthermore, for example, a part or all of the functions of the control unit 201 may be realized by a computer or the like provided outside the laser marker.

  The series of processes of the control unit 201 described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer capable of executing various functions by installing various programs by installing a computer incorporated in dedicated hardware.

  The program executed by the computer can be provided by being recorded on a removable medium such as a package medium. The program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

  The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

DESCRIPTION OF SYMBOLS 101 Laser marker 111 Laser head 112 Attachment 151 Laser oscillator 152 Light source 154 3D optical system 156 Galvano mirror 157 Light source 161 Camera 161a Image pick-up element 162 Lens 162a Main surface 163 Mirror 201 Control part 211 Imaging control part 212 Image processing part 213 Processing control part 501 Processing control part 501 512 Illuminating Device 601 Laser Marker 611 Attachment 621 Lens 622 Mirror 701 Laser Marker 711 Attachment 721 Lens 723 Illuminating Device

Claims (14)

In a laser processing apparatus including a laser head that emits a laser beam for processing a workpiece to be processed and includes a scanning unit for scanning the laser beam on a processing surface of the workpiece,
A camera,
A lens for forming an image of the processed surface on the image sensor of the camera;
An observation optical system including: a mirror that reflects light from the processing surface and makes the light incident on the lens ;
An image processing unit that performs image processing of an observation image that is an image captured by the camera;
A processing control unit that controls processing of the workpiece based on a result of image processing of the observation image ;
The observation optical system is provided between the scanning means and the processing surface in the height direction ;
The image processing unit, based on the amount of deviation between the center of the processing area by the laser light and the center of the shooting range of the camera, the area used by the observation image, the center coincides with the center of the processing area Laser processing equipment limited to the area to be used. The laser processing apparatus according to claim 1, wherein the observation optical system is disposed below a bottom surface of the laser head. The laser processing apparatus according to claim 1, wherein the mirror is disposed between the laser beam and the lens. The laser processing apparatus according to claim 1, wherein the laser light passes between the lens and the mirror. The camera, the lens, and the mirror are installed so that the processed surface, the main surface of the lens, and the imaging surface of the imaging device intersect substantially in a straight line. The laser processing apparatus of crab. And further comprising an illuminating device that illuminates the processed surface obliquely from above,
The illumination device is installed so that the specularly reflected light of the illumination light on a surface on which the observation optical system is focused coincides with the optical axis of the observation optical system. Laser processing equipment. The laser processing apparatus according to claim 1, wherein the lens is a telecentric lens. The machining control unit, laser machining apparatus according to any one of claims 1 to 7 for setting the processing position based on the result of the image processing of the observation image. Wherein the image processing unit, on the basis of the observation image imaging results, laser processing apparatus according to any one of claims 1 to 8 determines whether to execute the processing. Wherein the image processing unit, a laser machining apparatus according to any one of claims 1 to 9 for inspecting a processed state of said workpiece based on an image processing result of the observation image obtained by photographing the said workpiece after processing. Wherein the image processing unit, a laser machining apparatus according to any one of claims 1 to 10 to correct the trapezoidal distortion of the observed image. Wherein the image processing unit, a laser machining apparatus according to any one of claims 1 to 11 make vertical inversion of the observed image. A light source that emits predetermined measurement light from an oblique direction toward the center of the processing area by the laser light on the in-focus surface of the observation optical system;
The image processing unit detects an irradiation position of the measurement light in the observation image obtained by photographing the processed surface irradiated with the measurement light;
The machining control unit, based on the irradiation position of the measurement light in the observation image, a laser machining apparatus according to any one of claims 1 to 12 for adjusting the focus position of the machining optical system that emits the laser beam . A light source that irradiates the processing surface with predetermined measurement light via the scanning unit;
The image processing unit detects an irradiation position of the measurement light in the observation image obtained by photographing the processed surface irradiated with the measurement light;
The laser processing apparatus according to any one of claims 1 to 13 , wherein the processing control unit adjusts a focus position of a processing optical system that emits the laser light based on an irradiation position of the measurement light in the observation image. .

Images