Galvanometer scanner, and method for detecting the height position of a target point using a galvanometer scanner.

Abstract

To detect a height position of a target point by using a galvano-scanner.SOLUTION: A galvano-scanner includes a laser path, an observation path, a galvano-mirror, a camera, and a controller. The observation path is arranged coaxially with the laser path. The camera generates image data indicating an image including a target point, via the observation path. When an angle of an optical axis between the laser path and the observation path is a first angle, the controller calculates a first plane position indicating a plane position of the target point on an observation plane, on the basis of the image data. The controller changes the angle of the optical axis between the laser path and the observation path to a second angle different from the first angle, by the galvano-mirror, and calculates a second plane position indicating a plane position of the target point on the observation plane on the basis of the image data. The controller calculates a height position of the target point in a direction perpendicular to the observation plane on the basis of the first plane position and the second plane position.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a galvanometer scanner and a method for detecting the height position of a target point using the galvanometer scanner.

Background Art

[0002] A galvanometer scanner includes a galvanometer mirror, and operates the galvanometer mirror to move the focal position of a laser beam. Thereby, the galvanometer scanner can perform processing such as welding at a desired position on an object.

[0003] Some galvanometer scanners are provided with a position detection device for detecting the position of a target point on an object. The position detection device detects the position of the target point on the object by analyzing an image of the object. For example, in Patent Document 1, a coaxial camera for image inspection is provided to the galvanometer scanner as the position detection device. The coaxial camera for image inspection acquires an image of the object along the same path as the laser beam. The galvanometer scanner detects the position of the target point on the object by analyzing the image of the object.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-described galvanometer scanner, all points located on the optical axis of the position detection device for detecting an image are detected as points at the same position. Therefore, the height position of the target point cannot be detected. An object of the present disclosure is to detect the height position of a target point using a galvanometer scanner.

Means for Solving the Problems

[0006] A galvanometer scanner according to one aspect of this disclosure irradiates a target point on an object with laser light from a laser oscillator. The galvanometer scanner comprises a laser path, an observation path, a galvanometer mirror, a camera, and a controller. The laser path guides the laser light to the target point. The observation path merges with the laser path and is arranged coaxially with the laser path. The observation path guides an image including the target point. The galvanometer mirror is operable to change the angle of the optical axes of the laser path and the observation path. The camera captures an image via the observation path and generates image data showing the image. The controller calculates the planar position of the target point on a predetermined observation plane based on the image data. The controller calculates a first planar position indicating the planar position of the target point on the observation plane when the angle of the optical axes of the laser path and the observation path is a first angle. The controller changes the angle of the optical axes of the laser path and the observation path to a second angle different from the first angle using the galvanometer mirror. The controller calculates a second plane position, which indicates the planar position of the target point on the observation plane, when the angle of the optical axes between the laser path and the observation path is the second angle. Based on the first and second plane positions, the controller calculates the height position of the target point in a direction perpendicular to the observation plane.

[0007] Another aspect of the present disclosure relates to a method for detecting the height position of a target point in a direction perpendicular to a predetermined observation plane, using a galvanoscanner that illuminates the target point on an object with laser light from a laser oscillator. The galvanoscanner includes a laser path, an observation path, and a galvanoscanner mirror. The laser path guides the laser light to the target point. The observation path merges with the laser path and is arranged coaxially with the laser path. The observation path guides an image including the target point. The galvanoscanner mirror is operable to change the angle of the optical axes between the laser path and the observation path. The method comprises: acquiring image data showing an image obtained through an observation path; calculating a first planar position indicating the planar position of a target point on the observation plane based on the image data while the angle of the optical axes of the laser path and the observation path is a first angle; changing the angle of the optical axes of the laser path and the observation path to a second angle different from the first angle using a galvanometer mirror; calculating a second planar position indicating the planar position of a target point on the observation plane based on the image data while the angle of the optical axes of the laser path and the observation path is a second angle; and calculating the height position of the target point in a direction perpendicular to the observation plane based on the first planar position and the second planar position. [Effects of the Invention]

[0008] According to this disclosure, a galvanometer mirror acquires images in which the optical axis angles of the laser path and the observation path are different. The first and second planar positions of the target point calculated from each image differ according to the difference in the optical axis angles of the laser path and the observation path. Therefore, the height position of the target point can be calculated based on the first and second planar positions. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the configuration of a laser processing system according to an embodiment. [Figure 2] This is a flowchart showing the process for calculating the position of the target point. [Figure 3]This is a schematic diagram showing the optical axes of the laser path and observation path, and the object. [Figure 4] This figure shows an example of the first image of the observation range captured by the camera. [Figure 5] This figure shows an example of a second image of the observation area captured by the camera. [Figure 6] This diagram illustrates the process for machining an object that includes parts of different heights. [Figure 7] This diagram shows the process for determining whether or not machining is possible based on the height position of the target point. [Modes for carrying out the invention]

[0010] The laser processing system according to the embodiment will be described below with reference to the drawings. Figure 1 is a block diagram showing the configuration of the laser processing system 1. The laser processing system 1 is a system that welds an object using laser light. As shown in Figure 1, the laser processing system 1 comprises a laser oscillator 2 and a galvanometer scanner 3. The laser oscillator 2 is connected to the galvanometer scanner 3 by an optical fiber connector 4.

[0011] The galvanometer scanner 3 illuminates a target point P0 on the object 100 with laser light from the laser oscillator 2. The galvanometer scanner 3 moves the laser light from the laser oscillator 2 across the object 100. The galvanometer scanner 3 includes a head 11, a camera 12, and a controller 13. The head 11 includes a laser path 14. The laser path 14 guides the laser light to the target point P0 on the object 100.

[0012] The head 11 includes a collimating lens 21, a movable lens 22, a lens actuator 23, a focusing lens 24, a dichroic mirror 25, a galvanometer mirror 26, and a mirror actuator 27. The laser path 14 is a path that passes through the collimating lens 21, the movable lens 22, the focusing lens 24, the dichroic mirror 25, and the galvanometer mirror 26, and heads toward the target point P0.

[0013] The collimating lens 21 converts the laser light from the laser oscillator 2 into parallel light. The movable lens 22 is movable in a direction along the laser path 14. The lens actuator 23 moves the movable lens 22 in a direction along the laser path 14. By moving the movable lens 22 in a direction along the laser path 14, the position of the focal point of the laser light in the height direction is changed. The height direction refers to the direction from the object 100 toward the head 11, and corresponds to the Z direction in the drawing. The dichroic mirror 25 reflects the laser light that has passed through the focusing lens 24 toward the galvanometer mirror 26.

[0014] The galvanometer mirror 26 reflects the laser beam toward the object 100. The galvanometer mirror 26 is rotatably positioned. By rotating, the galvanometer mirror 26 moves the focal point of the laser beam. The galvanometer mirror 26 is connected to a mirror actuator 27, which is, for example, an electric motor. The mirror actuator 27 changes the rotation angle of the galvanometer mirror 26. Changing the rotation angle of the galvanometer mirror 26 changes the angle of the optical axis of the laser path 14. This changes the focal point of the laser beam.

[0015] The head 11 includes an observation path 15. The observation path 15 guides an image containing the target point P0 to the camera 12. The observation path 15 is a path from a predetermined observation range 30, passing through the galvanometer mirror 26 and the dichroic mirror 25, and heading towards the camera 12. The observation path 15 merges with the laser path 14 and is arranged coaxially with the laser path 14. More specifically, the observation path 15 is arranged coaxially with the portion of the laser path 14 that extends from the dichroic mirror 25 through the galvanometer mirror 26 to the target point P0.

[0016] The light showing the image of the object 100 within the observation range 30 (hereinafter simply referred to as "image") is reflected by the galvanometer mirror 26, passes through the dichroic mirror 25, and reaches the camera 12. The camera 12 is a monocular camera. The camera 12 captures an image within the observation range 30 via the observation path 15. The camera 12 generates image data showing the image within the observation range 30.

[0017] The optical axis of the observation path 15 passing through the center of the observation range 30 coincides with the optical axis of the laser path 14. Therefore, the position of the focus of the laser light coincides with the center of the observation range 30, that is, the center of the image. When the position of the focus is moved by the galvanometer mirror 26, the observation range 30 of the image also moves according to the movement of the position of the focus.

[0018] The laser light from the laser oscillator 2 passes through the laser path 14 and is irradiated onto the target point P0 on the object 100. Specifically, the laser light is sent from the laser oscillator 2 through the optical fiber connector 4 to the head 11. The laser light is adjusted to parallel light by passing through the collimating lens 21 within the head 11. The laser light passes through the movable lens 22 and the condenser lens 24, and is reflected toward the galvanometer mirror 26 at the dichroic mirror 25. The laser light is reflected by the galvanometer mirror 26 and irradiated onto the target point P0 on the object 100. Thereby, the object 100 is welded by the laser light at the target point P0.

[0019] The controller 13 controls the head 11 to move the position of the focus of the laser light. The controller 13 includes, for example, a processor and a memory. The controller 13 controls the mirror actuator 27 to change the rotation angle of the galvanometer mirror 26. The controller 13 changes the angle of the optical axis of the laser path 14 by controlling the rotation angle of the galvanometer mirror 26. Thereby, the controller 13 changes the position of the focus of the laser light (hereinafter referred to as the planar position) in the X-Y plane. The X-Y plane is a plane perpendicular to the height direction described above.

[0020] The controller 13 controls the lens actuator 23 to change the position of the movable lens 22. By controlling the position of the movable lens 22, the controller 13 changes the position of the focus of the laser beam in the height direction (Z direction).

[0021] The controller 13 controls the rotation angle of the galvanometer mirror 26 and the position of the movable lens 22 according to the input program and the set data indicating the welding conditions, so as to move the focus of the laser beam along a predetermined trajectory on the object 100. Thereby, the object 100 is welded according to the set data.

[0022] Also, the controller 13 calculates the position of the target point P0 by analyzing the image based on the image data. FIG. 2 is a flowchart showing the process for calculating the position of the target point P0. As shown in FIG. 2, in step S101, the controller sets the angle between the optical axes of the laser path 14 and the observation path 15 to the first angle A1. The controller controls the rotation angle of the galvanometer mirror 26 to set the angle between the optical axes of the laser path 14 and the observation path 15 to the first angle A1. Thereby, as shown in FIG. 3, the inclination angle of the optical axis Ax1 of the laser path 14 and the observation path 15 with respect to the predetermined observation plane PL1 is set to the first angle A1. In FIG. 3, the optical axis Ax1 indicates the optical axis of the laser path 14 and the optical axis of the observation path 15 passing through the center of the observation range 30, and is inclined at the first angle A1 with respect to the observation plane PL1.

[0023] In step 102, the controller 13 acquires the first image data. As shown in FIG. 4, the camera 12 acquires a first image 31 showing the observation range 30 in a state where the angle of the optical axis Ax1 of the laser path 14 is the first angle A1 through the observation path 15. The controller 13 acquires the first image data indicating the first image 31 generated by the camera 12.

[0024] In step S103, the controller 13 calculates the first planar position P1. As shown in Figure 3, the first planar position P1 indicates the planar position of the target point P0 on the observation plane PL1. The observation plane PL1 is a plane parallel to the XY plane described above. The controller 13 calculates the first planar position P1 as the intersection point of the optical axis Ax1' of the observation path 15, which is inclined at a first angle A1 with respect to the observation plane PL1 and passes through the target point P0, and the observation plane PL1.

[0025] In step S104, the controller 13 changes the angle of the optical axes of the laser path 14 and the observation path 15 to the second angle A2. The second angle A2 is different from the first angle A1. The controller 13 changes the angle of the optical axes of the laser path 14 and the observation path 15 from the first angle A1 to the second angle A2 by controlling the rotation angle of the galvanometer mirror 26. In Figure 3, the optical axis Ax2 represents the optical axis of the laser path 14, which is inclined at the second angle A2 with respect to the observation plane PL1, and the optical axis of the observation path 15, which passes through the center of the observation range 30. The first angle A1 and the second angle A2 may be predetermined and stored in the controller 13. Alternatively, the first angle A1 may be the initial value at the start of detection of the position of the target point P0, and the controller 13 may calculate the second angle A2 by adding a predetermined value to the first angle A1.

[0026] In step 105, the controller 13 acquires the second image data. As shown in Figure 5, the camera 12 acquires the second image 32 through the observation path 15, showing the observation range 30 when the angle of the optical axis Ax2 of the laser path 14 is the second angle A2. The controller 13 acquires the second image data showing the second image 32 generated by the camera 12.

[0027] In step S106, the controller 13 calculates the second planar position P2. As shown in Figure 3, the second planar position P2 indicates the planar position of the target point P0 on the observation plane PL1. The controller 13 calculates the second planar position P2 as the intersection point of the optical axis Ax2' of the observation path 15, which is tilted at a second angle A2 with respect to the observation plane PL1 and passes through the target point P0, and the observation plane PL1.

[0028] The first planar position P1 and the second planar position P2 are represented by coordinates in the XY plane. For example, as shown in Figure 4, the first planar position P1 is represented by coordinates (x1, y1). As shown in Figure 5, the second planar position P2 is represented by coordinates (x2, y1). In this embodiment, the controller fixes the optical axis in the Y-axis direction and moves it in the X-axis direction. However, the controller may fix the optical axis in the X-axis direction and move it in the Y-axis direction. Alternatively, the controller may move the optical axis in both the X-axis and Y-axis directions.

[0029] In step 107, the controller 13 calculates the height position of the target point P0. The controller 13 calculates the height position of the target point P0 based on the first planar position P1, the second planar position P2, the first angle A1, and the second angle A2. The height position of the target point P0 is expressed in coordinates in the Z direction.

[0030] As described above, the controller 13 analyzes images 31, 31, which include the target point P0 acquired by the camera 12, to detect the first planar position P1 and the second planar position P2 of the target point P0 in the observation plane PL1. Then, the controller 13 detects the height position of the target point P0 in a direction perpendicular to the observation plane PL1 from the first planar position P1, the second planar position P2, and the optical axis angles A1, A2. As a result, the galvanometer scanner 3 according to this embodiment can detect the three-dimensional position of the target point P0.

[0031] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0032] The processing performed by the laser processing system 1 is not limited to welding; it may also be other processing such as cutting or marking. The configuration of the galvanometer scanner 3 is not limited to that of the above embodiment and may be modified. For example, the arrangement of the collimating lens 21, movable lens 22, focusing lens 24, dichroic mirror 25, or galvanometer mirror 26 is not limited to that of the above embodiment and may be modified. Other mirrors or lenses may be added in the laser path 14 or observation path 15.

[0033] The controller 13 may change the height of the laser beam's focal point according to the height of the target point P0 while processing the object 100. For example, as shown in Figure 6, if the object 100 includes a first part 101 and a second part 102 of different heights, the controller 13 detects the height Z1 of the first part 101 and the height Z2 of the second part 102. When processing the first part 101, the controller 13 controls the galvanometer mirror 26 to match the height Z1 of the first part 101. When processing the second part 102, the controller 13 controls the galvanometer mirror 26 to match the height Z2 of the second part 102. As a result, the galvanometer scanner 3 can process the object 100, which includes parts of different heights, continuously and automatically.

[0034] The controller 13 may determine whether or not to process the object 100 based on the height position of the target point P0 before processing begins. For example, as shown in Figure 7, after the object 100 is placed in the laser processing system 1, the controller 13 detects the height position Z3 of the object 100 before processing begins. The controller 13 does not start processing if the height position Z3 of the object 100 is lower than the height Z4 of a predetermined reference position. Alternatively, the controller 13 does not start processing if the height position Z3 of the object 100 is higher than the height Z4 of a predetermined reference position. The height Z4 of the reference position may be determined, for example, by the limit position of the laser focal point. The controller 13 may output an alarm if it does not start processing. The alarm may be displayed on a display, for example. Alternatively, the alarm may be indicated by the illumination of a lamp. [Industrial applicability]

[0035] According to this disclosure, the height position of a target point can be detected using a galvanometer scanner. [Explanation of symbols]

[0036] 2: Laser oscillator, 3: Galvanometer scanner, 14: Laser path, 15: Observation path, 12: Camera, 13: Controller, 22: Movable lens, 26: Galvanometer mirror, P0: Target point, P1: First plane position, P2: Second plane position

Claims

1. A galvanometer scanner that irradiates a target point on an object with laser light from a laser oscillator, A laser path that guides the laser light to the target point, An observation path that merges with the aforementioned laser path, is arranged coaxially with the aforementioned laser path, and guides an image including the target point, A galvanometer mirror that can be operated to change the angle of the optical axis between the laser path and the observation path, A camera that captures the image via the observation path and generates image data showing the image, A controller that calculates the planar position of the target point on a predetermined observation plane based on the image data, Equipped with, The aforementioned controller, With the angle of the optical axes of the laser path and the observation path being a first angle, a first planar position indicating the planar position of the target point on the observation plane is calculated. The galvanometer mirror changes the angle of the optical axes between the laser path and the observation path to a second angle different from the first angle. With the angle of the optical axes of the laser path and the observation path being the second angle, a second planar position indicating the planar position of the target point on the observation plane is calculated. Based on the first plane position and the second plane position, the height position of the target point in a direction perpendicular to the observation plane is calculated. Galvanoscanner.

2. The system further includes a movable lens that changes the height position of the focal point of the laser beam in a direction perpendicular to the observation plane, The aforementioned controller, The movable lens changes the height position of the focal point of the laser beam according to the height position of the target point. The galvanometer scanner according to claim 1.

3. The controller determines whether or not to process the object with the laser beam based on the height position of the target point. The galvanometer scanner according to claim 1.

4. A method for detecting the height position of a target point on an object in a direction perpendicular to a predetermined observation plane, using a galvanometer scanner that irradiates the target point with laser light from a laser oscillator, The galvanometer scanner mentioned above is A laser path that guides the laser light to the target point, An observation path that merges with the aforementioned laser path, is arranged coaxially with the aforementioned laser path, and guides an image including the target point, A galvanometer mirror that can be operated to change the angle of the optical axis between the laser path and the observation path, Includes, To acquire image data showing the image obtained via the aforementioned observation path, With the angle of the optical axes of the laser path and the observation path being a first angle, a first planar position indicating the planar position of the target point on the observation plane is calculated based on the image data, The galvanometer mirror changes the angle of the optical axis between the laser path and the observation path to a second angle different from the first angle. With the angle of the optical axes of the laser path and the observation path being the second angle, a second planar position indicating the planar position of the target point on the observation plane is calculated based on the image data, Based on the first planar position and the second planar position, calculate the height position of the target point in a direction perpendicular to the observation plane. A method for providing this.

5. The system further comprises changing the height position of the focal point of the laser beam according to the height position of the target point. The method according to claim 4.

6. The system further comprises determining whether or not processing the object with the laser light is possible based on the height position of the target point. The method according to claim 4.

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