Laser processing head and laser machine

Abstract

Laser processing head (1A; 1B), comprising: a first lens group (11) into which laser light emanating from a light emitter (3) enters and which is designed to focus laser light, wherein the first lens group (11) is a lens group having a positive refractive power; a second lens group (12) to which the laser light which has passed through the first lens group (11) propagates, wherein the second lens group (12) is a lens group which has a positive refractive power; a third lens group (13), wherein the laser light which has passed through the second lens group (12) is propagated to the lens group, wherein the third lens group (13) is a lens group which has a negative refractive power; a fourth lens group (14) into which the laser light, which has passed through the third lens group (13), enters and which is designed to focus the laser light, wherein the fourth lens group (14) is a lens group which has a positive refractive power; an optical light flux conversion element (15) which can be arranged along an optical axis between the first lens group (11) and the second lens group (12) and is designed to convert a beam profile of the laser light; a first movement device (17) designed to move the first lens group (11) in a direction along the optical axis; a second movement device (18) configured to move the third lens group (13) in the direction along the optical axis; and a third movement device (19) configured to move the optical light flux conversion element (15) to a position along an optical axis between the first lens group (11) and the second lens group (12) and to a position outside the optical axis, wherein the first lens group (11), the second lens group (12), the third lens group (13) and the fourth lens group (14) form an optical transfer system (10) which forms an image of the light emitter (3) at a transfer position (6), wherein, if the optical luminous flux conversion element (15) exists along the optical axis, the optical luminous flux conversion element (15) is also included in the components of the optical transfer system (10), and wherein the optical luminous flux conversion element (15) is an axicon.

Description

Technical field

[0001] The present disclosure relates to a laser processing head which emits laser light and to a laser machine. Technological background

[0002] In laser processing, high-quality processing of workpieces made of different materials or thicknesses is expected, or processing must be carried out with high efficiency. Therefore, the laser machine must be able to appropriately control the beam diameter of the laser beam at a condensing position, or the beam profile (which is the intensity distribution of the laser beam across a cross-section). When processing a medium-thickness plate, it is necessary to shape the laser beam with high intensity at its outer edge, meaning a so-called annular beam profile, and to increase the beam diameter.

[0003] Patent document 1 discloses a laser processing machine comprising two axicon lenses and a movement mechanism that moves each axicon lens in the direction of the optical axis (optical axis direction) in which the laser processing machine switches a beam profile by changing the distance between the axicon lenses. In the laser processing machine according to patent document 1, laser light emitted from a light emitter passes through the two axicon lenses and a condenser lens in a laser processing head and is focused such that an image transfer position of the light emitter is located on or near a surface of the workpiece.

[0004] Patent literature 2 discloses an optical system for ophthalmology in which an optical light-flux conversion element in the form of a diffractive optical element can be arranged in an afocal section of a beam path. This afocal section of the beam path for the arrangement of the diffractive optical element is provided between the first lens group and the second lens group.

[0005] Patent literature 3 discloses a laser processing head which, in addition to two Axicon lenses that can be arranged in the beam path, uses exclusively lens groups with positive refractive power.

[0006] Patent literature 4 discloses a laser processing head that uses an axicon lens arranged along the beam path.

[0007] Patent literature 5 discloses the use of two Axicon lenses preferably in a laser processing head. Citation list for patent literature Patent literature 1: JP 2019 - 42 793 A Patent literature 2: US 2010 / 0 174 273 A1 Patent literature 3: WO 2021 / 166 037 A1 Patent literature 4: US 2019 / 0 062 196 A1 Patent Literature 5: CN 1 11 323 928 A Brief description of the invention Problem to be solved by the invention

[0008] According to the technique described in patent reference 1, an annular beam profile is obtained at a position spaced away from the transfer position in the direction of the optical axis, but the annular beam profile is not maintained at the transfer position itself. Furthermore, according to the technique described in patent reference 1, it is necessary to displace the workpiece position significantly from the transfer position in order to increase the beam diameter within the annular beam profile. This significant displacement of the workpiece position from the transfer position causes the edge of the laser beam at the workpiece to become blurred, thus degrading the processing quality. Therefore, the conventional technique described in patent reference 1 suffers from the problem that it is difficult to achieve high-quality processing by modifying the beam profile.

[0009] The present disclosure was made in light of the foregoing, and it is an object of the present disclosure to provide a laser processing head which can achieve high-quality processing by converting the beam profile. Means to solve the problem

[0010] The above problem is solved by a laser processing head having the combination of features of independent claim 1 and by a laser machine using this laser processing head according to claim 3. A preferred embodiment is described in dependent claim 2. Effects of the invention

[0011] A laser processing head according to the present disclosure has the effect of achieving high-quality processing through beam profile conversion. Brief description of the drawings Fig. Figure 1 is a diagram that represents an exemplary configuration of a laser processing head according to a first embodiment. Fig. Figure 2 is a diagram to illustrate the operation of the laser processing head according to the first embodiment. Fig. Figure 3 is a diagram showing a configuration of the laser processing head according to the first embodiment and a configuration according to a first comparative example of the first embodiment. Fig. Figure 4 is a diagram that represents a configuration according to a second comparative example of the first embodiment. Fig. Figure 5 is a diagram which presents an example in which a distance from a light emitter to a transfer position is changed by the laser processing head according to the first embodiment. Fig. Figure 6 is a diagram that shows an exemplary configuration of a laser processing head according to a second embodiment. Fig. Figure 7 is a first diagram to explain the operation of the laser processing head according to the second embodiment. Fig. Figure 8 is a second diagram to illustrate the operation of the laser processing head according to the second embodiment. Fig. Figure 9 is a diagram which represents an exemplary configuration of a laser machine according to a third embodiment. Fig. Figure 10 is a diagram which represents an exemplary configuration of a control circuit according to the first or second embodiment. Fig. Figure 11 is a diagram that shows an exemplary configuration of a dedicated hardware circuit according to the first or second embodiment. Description of embodiments

[0012] In the following, a laser processing head and a laser machine according to embodiments are described in detail with reference to the drawings. First embodiment.

[0013] Fig. Figure 1 is a diagram illustrating an exemplary configuration of a laser processing head 1A according to a first embodiment. The laser processing head 1A is provided in a laser machine. The laser processing head 1A emits a laser beam towards a workpiece 5. The workpiece 5 is a metal plate. The material of the workpiece 5 is a metal such as iron, stainless steel, or brass. It should be noted that the material and shape of the workpiece 5 are not limited to those described in the first embodiment.

[0014] A transmission line 2 is a transmission path for laser light from a light source to the laser processing head 1A. The transmission line 2 is, for example, an optical fiber. Fig. Figure 1 omits a representation of the light source. The laser processing head 1A comprises a housing 16, which forms an outer shell of the laser processing head 1A. Fig. Figure 1 schematically represents configurations housed in the enclosure 16. A light emitter 3, which is an emitting end of the transmission line 2, is connected to an interior of the enclosure 16. Laser light, propagated through the transmission line 2, enters the enclosure 16.

[0015] The laser processing head 1A comprises: a first lens group 11; a second lens group 12; a third lens group 13; a fourth lens group 14; and an optical light-flux conversion element 15. The first lens group 11, the second lens group 12, the third lens group 13, the fourth lens group 14, and the optical light-flux conversion element 15 are housed in the casing 16. The first lens group 11, the second lens group 12, the third lens group 13, and the fourth lens group 14 form an optical transfer system 10, which transfers an image from the light emitter 3. If the optical light-flux conversion element 15 exists along an optical axis, it is also included in the components of the optical transfer system 10.

[0016] The first lens group 11 is a lens group with positive refractive power. Laser light diverging from light emitter 3 enters the first lens group 11 and is focused. The second lens group 12 is a lens group with positive refractive power. Laser light that has passed through the first lens group 11 propagates to the second lens group 12.

[0017] The third lens group 13 has a negative refractive power. Laser light that has passed through the second lens group 12 propagates to the third lens group 13. The second lens group 12 and the third lens group 13 form a lens group that, at a transfer position, forms an image of the light emitter 3. The fourth lens group 14 has a positive refractive power. Laser light that has passed through the third lens group 13 enters the fourth lens group 14 and is focused. Laser light that has passed through the fourth lens group 14 is emitted outside the housing 16.

[0018] The optical light-flux conversion element 15 is arranged along an optical axis between the first lens group 11 and the second lens group 12. In the first embodiment, the optical axis is an optical axis of the optical transfer system 10. The optical light-flux conversion element 15 converts a beam profile of laser light. In the first embodiment, the optical light-flux conversion element 15 is an axicon lens. The axicon lens comprises a conical surface, which is a conic-convex surface, and a flat surface on one side opposite the conical surface. The optical light-flux conversion element 15 converts a Gaussian beam into an annular beam. By arranging the optical light-flux conversion element 15 along the optical axis, the laser processing head 1A generates an annular beam profile at or near the transfer position. In the first embodiment Fig. In the example shown, it is assumed that the transfer position coincides with a position on the workpiece 5.

[0019] The laser processing head 1A comprises a first movement device 17 and a second movement device 18. The first movement device 17 moves the first lens group 11 in a direction along the optical axis. The second movement device 18 moves the third lens group 13 in the direction along the optical axis.

[0020] A controller 4 controls the entire laser machine, including the laser processing head 1A. The controller 4 transmits a control signal to both the first motion device 17 and the second motion device 18. The first motion device 17 moves the first lens group 11 in response to the control signal. The second motion device 18 moves the third lens group 13 in response to the control signal. The controller 4 controls the first motion device 17 and the second motion device 18 by sending a control signal to each of the first motion device 17 and the second motion device 18.

[0021] In Fig. In Figure 1, each of the first lens group (11), the second lens group (12), the third lens group (13), and the fourth lens group (14) is represented as a single lens. However, each of the first lens group (11), the second lens group (12), the third lens group (13), and the fourth lens group (14) is not limited to a single lens and can comprise multiple lenses. The number of lenses in each of the first lens group (11), the second lens group (12), the third lens group (13), and the fourth lens group (14) can be any number.

[0022] Next, the operation of the laser processing head 1A is described when it converts a beam profile of the laser beam emitted by the laser processing head 1A.

[0023] Fig. Figure 2 is a diagram to illustrate the operation of the laser processing head 1A according to the first embodiment. Fig. Figure 2 represents a state in which each of the first lens group 11 and the third lens group 13 are moved in the direction of the optical axis. Fig. Figure 2 shows a main configuration of the laser processing head 1A, and a representation of other configurations of the laser processing head 1A is omitted.

[0024] Here, reference is made to a location in a left part of Fig. The state shown in Figure 2 is referred to as a first state. Additionally, reference is made to a state in a right-hand part of Fig. The state shown in Figure 2 is referred to as a second state. In the first state, the first lens group 11 moves towards the light emitter 3, and the third lens group 13 moves towards the fourth lens group 14. This means that the first state is a state in which the first lens group 11 and the third lens group 13 have moved away from each other. In contrast, in the second state, the first lens group 11 moves towards the second lens group 12, and the third lens group 13 moves towards the second lens group 12. This means that the second state is a state in which the first lens group 11 and the third lens group 13 have moved towards each other.The state of the laser processing head 1A is switched between the first state and the second state by moving the first lens group 11, which is caused by the first movement device 17, and by moving the third lens group 13, which is caused by the second movement device 18. A [missing text] Fig. The double arrow shown in point 2 indicates that the state of the laser processing head 1A can be switched between the first state and the second state.

[0025] Beam profile 21 is a beam profile in which the laser processing head 1A is in the first state. Beam profile 22 is a beam profile when the laser processing head 1A is in the second state. Both beam profiles 21 and 22 are annular beam profiles. The beam diameter in beam profile 21 is larger than the beam diameter in beam profile 22. It should be noted that the beam diameter of the annular laser beam is referred to as a ring diameter in the following description.

[0026] When the laser processing head 1A is in the second state, its state is switched to the first state by moving the first lens group 11 and the third lens group 13 away from each other in a state in which image formation of the light emitter 3 at the transfer position is maintained. As a result, the laser processing head 1A increases the ring diameter from beam profile 22 to beam profile 21.

[0027] When the laser processing head 1A is in the first state, it switches to the second state by moving the first lens group 11 and the third lens group 13 in directions where they approach each other, while maintaining an image formation of the light emitter 3 at the transfer position. As a result, the laser processing head 1A reduces the ring diameter from beam profile 21 to beam profile 22. In this way, the laser processing head 1A transforms the beam profile of the laser beam while maintaining an image formation of the light emitter 3 at the transfer position.

[0028] The laser processing head 1A can be switched between the first and second states depending on the material or thickness of the workpiece 5. For example, when laser processing a medium-thickness plate approximately 20 mm thick, high-quality and efficient processing can be achieved by setting the laser processing head 1A to the first state. Because the laser processing head 1A can convert the beam profile while maintaining an image of the light emitter 3 at the transfer position, it is possible to perform high-quality processing compared to cases where it is necessary to move the workpiece significantly away from the transfer position.The laser processing head 1A can easily select a suitable beam diameter for a processing target by moving the first lens group 11 and the third lens group 13. By appropriately selecting a beam diameter in accordance with the material or thickness of the workpiece 5, it is possible to improve processing quality and productivity.

[0029] Next, a functional effect of a configuration of the laser processing head 1A according to the first embodiment is described. Here, a configuration according to a comparative example is presented, and a functional effect achieved by the configuration of the laser processing head 1A is described by comparison with the case of the comparative example.

[0030] Fig. Figure 3 is a diagram showing a configuration of a laser processing head 1A according to the first embodiment and a configuration according to a first comparative example of the first embodiment. A left part of Fig. Figure 3 represents a configuration included in the laser processing head 1A according to the first embodiment. A right part of Fig. Figure 3 represents a configuration according to the first comparative example. The configuration according to the first comparative example differs from the configuration of the first embodiment in that the optical light flux conversion element 15 is arranged between the light emitter 3 and the first lens group 11.

[0031] In the configuration according to the first comparative example, the ring diameter can also be changed by moving the first lens group 11 and the third lens group 13. When changing the ring diameter, the ring diameter can be made larger as the distance between the light emitter 3 and the optical luminous flux conversion element 15 increases. In the case of the first comparative example, since the optical luminous flux conversion element 15 is located immediately after the light emitter 3, the distance between the light emitter 3 and the first lens group 11 increases as the distance between the light emitter 3 and the optical luminous flux conversion element 15 increases. As the distance between the light emitter 3 and the first lens group 11 increases, it is necessary to increase the size of the optical system downstream of the first lens group 11 in order to capture the diverging laser light from the light emitter 3.

[0032] In contrast, the optical light-flux conversion element 15 in the laser processing head 1A according to the first embodiment is arranged between the first lens group 11 and the second lens group 12. Therefore, compared to the case of the first comparative example, it is easy to ensure a large distance between the light emitter 3 and the optical light-flux conversion element 15. The laser processing head 1A is designed such that the optical light-flux conversion element 15 is arranged between the first lens group 11 and the second lens group 12, and each is moved by the first lens group 11 and the third lens group 12, so that a certain degree of change in the ring diameter can be increased without increasing the size of the optical system behind the first lens group 11. Fig. 3 The distance between the light emitter 3 and the first lens group 11 in the first embodiment is equal to the distance between the light emitter 3 and the optical luminous flux conversion element 15 in the first comparative example, but the optical system behind the first lens group 11 is smaller in the case of the first embodiment than in the first comparative example.

[0033] Furthermore, in the first comparative example, instead of ensuring a large distance between the light emitter 3 and the optical light-flux conversion element 15, the ring diameter can be changed by reducing the opening angle of the conical shape of the optical light-flux conversion element 15. However, if the opening angle of the conical shape of the optical light-flux conversion element 15 is reduced, highly precise alignment of the optical light-flux conversion element 15 is required. The laser processing head 1A according to the first embodiment can increase the ring diameter without reducing the opening angle of the conical shape of the optical light-flux conversion element 15.

[0034] Since the optical light-conversion element 15 is positioned closer to the light emitter 3, the intensity of the laser light entering the optical light-conversion element 15 increases. As the intensity of the laser light entering the optical light-conversion element 15 increases, there is a possibility that the optical light-conversion element 15 will be damaged by a rise in temperature. In the case of the first comparative example, because the optical light-conversion element 15 is located directly behind the light emitter 3, its position tends to be close to the light emitter 3. In contrast, in the laser processing head 1A according to the first embodiment, the optical light-conversion element 15 is located between the first lens group 11 and the second lens group 12.Therefore, compared to the first example, the optical light-flux conversion element 15 can be spaced further away from the first light emitter 3. The laser processing head 1A can prevent an increase in the intensity of the laser light entering the optical light-flux conversion element 15 and can reduce the probability of damage to the optical light-flux conversion element 15.

[0035] Fig. Figure 4 is a diagram illustrating a configuration according to a second comparative example of the first embodiment. The configuration according to the second comparative example differs from the configuration of the first embodiment in that the optical light-flux conversion element 15 is arranged between the third lens group 13 and the fourth lens group 14. A left part of Fig. Figure 4 represents a state in which the first lens group 11 is moved towards the light emitter 3 and the third lens group 13 is moved towards the optical light-flux conversion element 15. A right part of Fig. Figure 4 represents a state in which the first lens group 11 is moved in the direction of the second lens group 12, and the third lens group 13 is moved in the direction of the second lens group 12. A Fig. The double arrow shown in Figure 4 indicates that the configuration according to the second comparison example is between the state shown in the left part of Fig. 4 is shown and the state that is in the right part of Fig. As shown in 4, it can be switched.

[0036] In the case of the second comparative example, the thickness of the ring in the annular beam profile changes primarily by moving the first lens group 11 and the third lens group 13. A ring width is present in a beam profile 23 in the left part of Fig. The state shown in section 4 is large, and the ring width is in a beam profile 24 in the right part of Fig. In the state shown in 4, the change is small. In the case of the second comparison example, a change in the thickness of the ring is large, whereas a change in the ring diameter is small.

[0037] The laser processing head 1A according to the first embodiment can change the ring diameter significantly without significantly increasing the ring thickness. The laser processing head 1A can increase the energy density in an outer edge section compared to cases where the ring thickness increases significantly. As a result, the laser processing head 1A can achieve high-quality and efficient processing for a given workpiece material 5 or thickness 5.

[0038] As described above, one way of changing the beam profile by moving the first lens group 11 and the third lens group 13 differs depending on the position of the optical light-flux conversion element 15. By arranging the optical light-flux conversion element 15 along the optical axis between the first lens group 11 and the second lens group 12 in the laser processing head 1A, it is possible to achieve high-quality and highly efficient processing on workpieces 5 made of different materials or thicknesses.

[0039] Furthermore, the laser processing head 1A can change the distance from the light emitter 3 to the transfer position while maintaining a transfer magnification by moving the first lens group 11 and the third lens group 13. Fig. Figure 5 is a diagram which presents an example in which a distance from the light emitter 3 to the transfer position is changed by the laser processing head 1A according to the first embodiment.

[0040] A left part of Fig. Figure 5 represents a state in which a transfer position 6 on the laser processing head 1A is set relative to a position on the workpiece 5. A right part of Fig. 5 represents a state in which the transfer position 6 is set on a side that, relative to a position of the workpiece 5, is opposite the laser processing head 1A. A Fig. The double arrow shown in Figure 5 indicates that the laser processing head 1A is positioned between the point on the left side of the image. Fig. 5 depicted state and the one in the right part of Fig. The laser processing head 1A can be switched to the state shown in Figure 5. It can change the transfer position 6 in the direction of the optical axis by appropriately adjusting the position of the first lens group 11 and the position of the third lens group 13. As a result, the laser processing head 1A can achieve high-quality and highly efficient processing on workpieces 5 made of different materials or thicknesses.

[0041] Since the number of optical light-flux conversion elements 15 required for the laser processing head 1A is one, the laser processing head 1A can reduce the cost of the optical system compared to a case where two axicon lenses are required, as described in patent literature 1. Additionally, when the two axicon lenses described in patent literature 1 are moved, there are concerns about damage to one of the axicon lenses due to contact between them. A laser processing head 1A can eliminate such concerns.

[0042] It is noted that the laser processing head 1A in the preceding description includes the motion device that moves the first lens group 11 and the motion device that moves the third lens group 13. The laser processing head 1A may also include a motion device that moves an optical component other than the first lens group 11 or the third lens group 13. For example, a motion device for moving the second lens group 12 or the fourth lens group 14 may be added to the laser processing head 1A. As a result, the laser processing head 1A can appropriately perform adjustments to improve processing quality or productivity.

[0043] In the preceding description, the optical light-transforming element 15 is an axicon lens, but the optical light-transforming element 15 can be an optical element other than an axicon lens. The optical light-transforming element 15 can be an optical element with a shape other than a conical one, such as a polyhedral or aspherical shape. The optical light-transforming element 15 can be an array-type optical element in which many shapes, such as a conical, a polyhedral, and an aspherical shape, are arranged. The optical light-transforming element 15 is not limited to a refractive optical element and can also be a diffracting optical element.

[0044] According to the first embodiment, the laser processing head 1A comprises: the first lens group 11; the second lens group 12; the third lens group 13; the fourth lens group 14; and the optical light-flux conversion element 15, which is arranged along the optical axis between the first lens group 11 and the second lens group 12. The laser processing head 1A further comprises the first movement device 17, which moves the first lens group 11, and the second movement device 18, which moves the third lens group 13. The laser processing head 1A can easily convert the beam profile of a laser beam by moving the first lens group 11 and the third lens group 13. The laser processing head 1A can improve processing quality and productivity by selecting the beam profile according to the material or thickness of the workpiece 5.As described above, the 1A laser processing head achieves high-quality processing through beam profile conversion. Furthermore, the 1A laser processing head can improve productivity. Second embodiment

[0045] Fig. Figure 6 is a diagram illustrating an exemplary configuration of a laser processing head 1B according to a second embodiment. In addition to the configurations similar to those of the laser processing head 1A according to the first embodiment, the laser processing head 1B comprises a third movement device 19. In the second embodiment, components identical to those in the first embodiment described above are designated by identical reference numerals, and configurations differing from those of the first embodiment are described.

[0046] The third movement device 19 moves the optical light-flux conversion element 15 to a position along an optical axis between the first lens group 11 and the second lens group 12 and to a position outside the optical axis. In the Fig. In the example shown in Figure 6, the third motion device moves the optical light-flux conversion element 15 by rotating the optical light-flux conversion element 15 about an axis perpendicular to the optical axis. The optical light-flux conversion element 15 is attached to a rotatable mount, which is connected to the third motion device 19. The optical light-flux conversion element 15 moves together with the mount due to the rotation of the third motion device 19. A representation of the mount has been omitted.

[0047] The controller 4 transmits a control signal to each of the first motion device 17, the second motion device 18, and the third motion device 19. The third motion device 19 moves the optical light-flux conversion element 15 in response to the control signal. The controller 4 controls the first motion device 17, the second motion device 18, and the third motion device 19 by sending a control signal to each of the first motion device 17, the second motion device 18, and the third motion device 19.

[0048] In Fig. Figure 6 shows a solid line indicating the optical luminous flux conversion element 15 when the optical luminous flux conversion element 15 is arranged at a position along the optical axis. Fig. Figure 6 shows a dashed line indicating the optical luminous flux conversion element 15 and part of the third movement device 19 when the optical luminous flux conversion element 15 is outside the optical axis. Further, in Fig. Figure 6 shows a dashed line representing a trajectory along which the optical light-flux conversion element 15 moves. The first movement device 17 moves the first lens group 11 when the third movement device 19 moves the optical light-flux conversion element 15. By moving the first lens group 11 before the movement of the optical light-flux conversion element 15, the laser processing head 1B can prevent the first lens group 11 from obstructing the movement of the optical light-flux conversion element 15. Fig. 6 A dashed line indicates the first lens group 11 and part of the first moving device 17 when the first lens group 11 was moved before the movement of the optical light flux conversion element 15.

[0049] Next, the operation of the laser processing head 1B is described when it converts a beam profile of a laser beam emitted by the laser processing head 1B.

[0050] Fig. Figure 7 is a first diagram to explain the operation of the laser processing head 1B according to the second embodiment. Fig. Figure 7 represents a state in which the optical light-flux conversion element 15 is arranged along the optical axis, and a state in which the optical light-flux conversion element 15 is arranged at a position outside the optical axis. Fig. Figure 17 shows a main configuration of the laser processing head 1B, and a representation of other configurations of the laser processing head 1B has been omitted.

[0051] Here, reference is made to a location in a left part of Fig. The state depicted in section 7 is referred to as a third state. Furthermore, reference is made to a state located in a right-hand part of Fig. The state shown in Figure 7 is referred to as a fourth state. In the third state, the optical light-flux conversion element 15 is arranged along the optical axis. The positional dependency between the first lens group 11, the third lens group 13, and the optical light-flux conversion element 15 is the same in the third state as in the left part of Figure 7. Fig. 2 the first state shown. A beam profile 15 in the third state is similar to the one in Fig. 2 shown beam profile 21. In the third state, the laser processing head 1B changes a ring diameter comparable to the case of the first embodiment by appropriately moving the first lens group 11 and the third lens group 13.

[0052] From the third state, the first lens group 11 is moved by the first moving device 17 towards the light emitter 3, and then the third moving device 19 moves the optical light-flux conversion element 15 out of the optical axis. This means that the third moving device 19 takes the optical light-flux conversion element 15 out of the optical axis. In the Fig. In the example shown in Figure 7, the optical light-flux conversion element 15 is moved out of the optical axis, and then the first movement device 17 moves the first lens group 11 back to its original position. As a result, the laser processing head 1B transitions from the third state to the fourth state. As described above, the state of the laser processing head 1B is switched between the third and fourth states by moving the optical light-flux conversion element 15 using the third movement device 19. Furthermore, when the optical light-flux conversion element 15 is to be moved by the third movement device 19, the laser processing head 1B moves the first lens group 11 using the first movement device 17. A Fig. The double arrow shown in figure 7 indicates that the state of the laser processing head 1B can be switched between the third state and the fourth state.

[0053] In the fourth state, an image of the light emitter 3 is transferred through the optical transfer system 10. If the transmission line 2 is an optical fiber, the transferred image of the light emitter 3 is circular. In this case, a circular beam profile 26 can be obtained in the fourth state. The laser processing head 1B can convert the beam profile by inserting the optical light-flux conversion element 15 into the optical axis and then removing it from the optical axis.

[0054] Furthermore, in the fourth state, the laser processing head 1B can change the beam diameter by appropriately moving the first lens group 11 and the third lens group 13.

[0055] Fig. Figure 8 is a second diagram to illustrate the operation of the laser processing head 1B according to the second embodiment. Fig. Figure 8 represents a state in which both the first lens group 11 and the third lens group 13 are moved along the optical axis in the fourth state. Fig. Figure 8 shows a main configuration of the laser processing head 1B, and a representation of other configurations of the laser processing head 1B is omitted.

[0056] In a left part of Fig. In the state shown in Figure 8, the first lens group 11 is moved towards the light emitter 3, and the third lens group 13 is moved towards the fourth lens group 14. This means that the state shown in the left part of Figure 8 is... Fig. The state shown in Figure 8 is a state in which the first lens group 11 and the third lens group 13 have been moved away from each other. However, in a right-hand part of Fig. Figure 8 shows a state in which the first lens group 11 is moved in the direction of the second lens group 12, and the third lens group 13 is moved in the direction of the second lens group 12. This means that the one in the right part of Fig. The state shown in Figure 8 is a state in which the first lens group 11 and the third lens group 13 have been moved in directions approaching each other. A state in Fig. The double arrow shown in Figure 8 indicates that the laser processing head 1B is positioned between the point in the left part of Fig. 8 depicted state and the one in the right part of Fig. The laser processing head 1B changes the transfer magnification of the optical transfer system 10 by moving the first lens group 11 and the third lens group 13.

[0057] In the right part of Fig. In the state shown in Figure 8, a beam diameter in a beam profile 28 is smaller than a beam diameter in a beam profile 27 in the left part of Fig. The state shown in Figure 8. By moving the first lens group 11 and the third lens group 13 in directions approaching each other, the beam diameter decreases. Additionally, by moving the first lens group 11 and the third lens group 13 in directions away from each other, the beam diameter increases. In this way, the laser processing head 1B changes the beam diameter of the laser beam.

[0058] The laser processing head 1B switches the shape of the beam profile between an annular and a circular shape by moving the optical light-flux conversion element 15. The laser processing head 1B changes the diameter of the annular beam profile by moving the first lens group 11 and the third lens group 13 to the third state, in which the optical light-flux conversion element 15 is positioned along the optical axis. The laser processing head 1B changes the diameter of the circular beam profile by moving the first lens group 11 and the third lens group 13 to the fourth state, in which the optical light-flux conversion element 15 is retracted outside the optical axis.

[0059] By moving the first lens group 11, the third lens group 13, and the optical light-flux conversion element 15, the laser processing head 1B can easily select a ring diameter or beam diameter and a beam profile suitable for a processing target. By appropriately selecting the ring diameter or beam diameter and the beam profile in accordance with the material or thickness of the workpiece 5, it is possible to improve the processing quality and increase productivity.

[0060] The laser processing head 1B creates a clearance for moving the optical light-flux conversion element 15 by moving the first lens group 11 when the third motion device 19 moves the optical light-flux conversion element 15. Therefore, the laser processing head 1B does not always need to ensure the clearance for moving the optical light-flux conversion element 15 within the optical system, and the optical system can be miniaturized. The laser processing head 1B also uses the first motion device 17, which is used to convert the ring diameter, as a motion device for creating the clearance. It is not necessary for the laser processing head 1B to provide a separate motion device for creating the clearance, distinct from the first motion device 17 used to convert the ring diameter.If the optical light-flux conversion element 15 is moved by rotating the optical light-flux conversion element 15 about an axis perpendicular to the optical axis, the free space through which the optical light-flux conversion element 15 passes is required along the optical axis, so that the effect of the configuration in which the first lens group 11 is moved by the first moving device 17 is large.

[0061] With a simple configuration of rotating the optical light-flux conversion element 15 about an axis perpendicular to the optical axis, the laser processing head 1B can move the optical light-flux conversion element 15 to a position on the optical axis between the first lens group 11 and the second lens group 12, and to a position off the optical axis. It should be noted that the third movement device 19 is not limited to a mechanism that rotates the optical light-flux conversion element 15 about an axis perpendicular to the optical axis. The third movement device 19 can also be a mechanism that rotates the optical light-flux conversion element 15 about an axis parallel to the optical axis. Alternatively, the third movement device 19 can be a mechanism that moves the optical light-flux conversion element 15 along a plane perpendicular to the optical axis.The third movement device 19 need only be a mechanism that moves the optical light-flux conversion element 15 to a position on the optical axis between the first lens group 11 and the second lens group 12, and to a position off the optical axis. If the light-flux conversion element 15 is rotated about an axis perpendicular to the optical axis, the housing 16 can be reduced in size compared to a case in which the light-flux conversion element 15 is rotated about an axis parallel to the optical axis, or a case in which the light-flux conversion element 15 is moved along a plane perpendicular to the optical axis.

[0062] The laser processing head 1B is configured to move the optical light-flux conversion element 15, thereby switching between the presence and absence of the effect of the optical light-flux conversion element 15 using an optical system contained within the laser processing head 1B. By switching between the presence and absence of the effect of the optical light-flux conversion element 15, the laser processing head 1B can switch between the annular beam profile and a beam profile that is a transfer image of the light emitter 3. Furthermore, by moving the first lens group 11 and moving the third lens group 13, the laser processing head 1B can perform a beam profile conversion by changing the ring diameter and a beam profile conversion by changing the magnification of the transfer image.

[0063] According to the second embodiment, the laser processing head 1B moves the optical light-flux conversion element 15, using the third movement device 19, to a position along the optical axis between the first lens group 11 and the second lens group 12, and to a position outside the optical axis. The laser processing head 1B can easily convert the beam profile of the laser beam by moving the optical light-flux conversion element 15. Furthermore, the laser processing head 1B can easily convert the beam profile of a laser beam by moving the first lens group 11 and the third lens group 13. The laser processing head 1B can improve processing quality and productivity by selecting the beam profile according to the material or thickness of the workpiece 5.As described above, the 1B laser processing head achieves high-quality processing through beam profile conversion. Furthermore, the 1B laser processing head can improve productivity. Third embodiment

[0064] In a third embodiment, a laser machine comprising the laser processing head 1A or the laser processing head 1B is described. Fig. Figure 9 is a diagram illustrating an exemplary configuration of a laser machine 100 according to the third embodiment. The in Fig. Figure 9 of the illustrated laser machine 100 comprises the laser processing head 1A according to the first embodiment. The laser machine 100 can, instead of the laser processing head 1A, comprise the laser processing head 1B according to the second embodiment. In the third embodiment, components identical to those in the first or second embodiment are designated with identical reference numerals, and configurations that differ from those in the first or second embodiment are described in particular.

[0065] The laser machine 100 comprises: a laser oscillator 7 as a light source that emits laser light; the laser processing head 1A; the transmission line 2 as a transmission path for the laser light from the laser oscillator 7 to the laser processing head 1A; a worktable 8 on which the workpiece 5 is placed; and the control unit 4, which controls the laser machine 100. The laser machine 100 is designed to process the workpiece 5 by irradiating the workpiece 5 with a laser beam 9 emitted by the laser processing head 1A. The laser processing head 1A blows processing gas onto the workpiece 5. A device for blowing out the processing gas is not shown.

[0066] The laser machine 100 moves the laser beam 9 and the workpiece 5 by moving the worktable 8 relative to the laser processing head 1A. The worktable 8 is movable in a two-dimensional direction perpendicular to a central axis of the laser beam 9. Fig. The white double arrows 9 indicate directions in which the worktable 8 can be moved. It should be noted that the laser machine 100 can move the laser beam 9 and the workpiece 5 relative to each other without moving the worktable 8. The laser machine 100 can hold a fixed position of the worktable 8 and control the point of incidence of the laser beam 9 on the workpiece 5.

[0067] The controller 4 transmits a control signal to each of the laser processing head 1A, the laser oscillator 7, and the worktable 8. The laser oscillator 7 emits the laser light in response to the control signal. As described in the first embodiment, the laser processing head 1A moves the first lens group 11 and the third lens group 13 in response to the control signal. The worktable 8 is actuated in response to the control signal. In this way, the controller 4 controls each of the laser processing head 1A, the laser oscillator 7, and the worktable 8.

[0068] According to the third embodiment, the laser machine 100 comprises the laser processing head 1A or the laser processing head 1B, such that the workpiece can be processed by appropriately selecting a beam profile in accordance with the material or thickness of the workpiece 5. The laser machine 100 can improve processing quality and productivity by selecting the beam profile. The laser machine 100 achieves high-quality processing through beam profile conversion. Additionally, the laser machine 100 can improve productivity. The laser machine 100 can improve processing quality and productivity, particularly for a medium-thickness plate or a plate thicker than a medium-thickness plate.

[0069] Next, a hardware configuration for implementing the controller 4 according to the first or second embodiment is described. The controller 4 is implemented by a processing circuit. The processing circuit can be a circuit in which a processor executes software, or it can be a dedicated circuit.

[0070] In a case where the processing circuit is implemented by software, the processing circuit is, for example, a Fig. 10 control circuits shown. Fig. Figure 10 is a diagram illustrating an exemplary configuration of a control circuit 30 according to the first or second embodiment. The control circuit 30 comprises an input unit 31, a processor 32, a memory unit 33, and an output unit 34.

[0071] The input unit 31 is an interface circuit that receives data input from outside the control circuit 30 and forwards the data to the processor 32. The output unit 34 is an interface circuit that sends data from the processor 32 or the memory unit 33 to outside the control circuit 30. In a case where the processing circuit receives the data in Fig. In the control circuit 30 shown in Figure 10, the functions of the controller 4 are implemented by the processor 32, which reads and executes a program stored in the memory unit 33. The memory unit 33 is also used as temporary memory in each of the processes carried out by the processor 32.

[0072] The processor 32 is a central processing unit (CPU), a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, or a digital signal processor (DSP). The memory unit 33 corresponds, for example, to a non-volatile or volatile semiconductor memory such as random access memory (RAM), read-only memory (ROM), flash memory, erasable programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM) (registered trademark), a magnetic disk, a floppy disk, an optical disk, a compact disk, a minidisc, a digital versatile disk (DVD), or the like.

[0073] Fig. 10 is an example of hardware in a case where the controller 4 is implemented by the general-purpose processor 32 and the memory unit 33, but the controller 4 can also be implemented by a dedicated hardware circuit. Fig. Figure 11 is a diagram which represents an exemplary configuration of a dedicated hardware circuit 35 according to the first or second embodiment.

[0074] The dedicated hardware circuit 35 comprises the input unit 31, the output unit 34, and a processing circuit 36. The processing circuit 36 ​​can be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a circuit obtained by combining the same. It should be noted that the control 4 can be implemented by combining the control circuit 30 and the hardware circuit 35.

[0075] The configuration described in each of the foregoing embodiments represents an example of the contents of this disclosure. The configuration of each embodiment can be combined with other known technologies. The configurations of the individual expressions can be suitably combined. A part of the configuration of each embodiment can be omitted or modified without departing from the concept of this disclosure. Reference symbol list 1A, 1B Laser processing head; 2 transmission lines; 3 light emitters; 4 Control; 5 workpieces; 6 transfer positions; 7 Laser oscillator; 8 Work table; 9 Laser beam; 10 optical transfer system; 11 first lens group; 12 second lens group; 13 third lens group; 14 fourth lens group; 15 optical light flux conversion element; 16 cases; 17 first motion device; 18 second motion device; 19 third motion device; 21, 22, 23, 24, 25, 26, 27, 28 Beam profile; 30 Control circuit; 31 Input unit; 32 processor; 33 storage units; 34 output units; 35 Hardware circuitry; 36 Processing circuit; 100 laser machines.

Claims

[1] Laser processing head (1A; 1B), comprising: a first lens group (11) into which laser light emanating from a light emitter (3) enters and which is designed to focus laser light, wherein the first lens group (11) is a lens group having a positive refractive power; a second lens group (12) to which the laser light which has passed through the first lens group (11) propagates, wherein the second lens group (12) is a lens group which has a positive refractive power; a third lens group (13), wherein the laser light which has passed through the second lens group (12) is propagated to the lens group, wherein the third lens group (13) is a lens group which has a negative refractive power; a fourth lens group (14) into which the laser light, which has passed through the third lens group (13), enters and which is designed to focus the laser light, wherein the fourth lens group (14) is a lens group which has a positive refractive power; an optical light flux conversion element (15) which can be arranged along an optical axis between the first lens group (11) and the second lens group (12) and is designed to convert a beam profile of the laser light; a first movement device (17) designed to move the first lens group (11) in a direction along the optical axis; a second movement device (18) configured to move the third lens group (13) in the direction along the optical axis; and a third movement device (19) configured to move the optical light flux conversion element (15) to a position along an optical axis between the first lens group (11) and the second lens group (12) and to a position outside the optical axis, wherein the first lens group (11), the second lens group (12), the third lens group (13) and the fourth lens group (14) form an optical transfer system (10) which forms an image of the light emitter (3) at a transfer position (6), wherein, if the optical luminous flux conversion element (15) exists along the optical axis, the optical luminous flux conversion element (15) is also included in the components of the optical transfer system (10), and wherein the optical luminous flux conversion element (15) is an axicon. [2] Laser processing head (1A; 1B) according to claim 1, wherein the first movement device (17) is configured to move the first lens group (11) when the third movement device (19) moves the optical light-flux conversion element (15), and the first moving device (17) moves the first lens group (11) before the third moving device (19) moves the optical light flux conversion element (15). [3] Laser machine (100), comprising: a light source (7) designed to emit laser light; and the laser processing head (1A; 1B) according to one of claims 1 or 2.

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