Optical unit, laser processing device, and lens barrel

Abstract

An optical unit (2) is provided with: a plurality of lens groups (20) that are disposed between an incident side and an exit side in an optical axis direction (Z) in which a laser beam (LB) is guided in a laser processing device (1); a housing (30) that has an incidence port (30a) provided on the incident side in the optical axis direction and an exit port (30b) provided on the exit side, and that accommodates the plurality of lens groups; a first holding unit (41) that holds a first lens group disposed on the exit side of the plurality of lens groups, in the housing; and a first drive unit (61) that drives the first holding unit between a position in which the first lens group is extended out from the exit port of the housing toward the exit side in the optical axis direction and a position closer to the incident side than the position when the first lens group is extended out.

Description

Optical unit, laser processing device and lens barrel

[0001] The present disclosure relates to an optical unit, a laser processing apparatus including the optical unit, and a lens barrel of the optical unit.

[0002] Patent Document 1 discloses a beam shaping unit that focuses laser light on a workpiece for laser material processing. The beam shaping unit includes a first optical element onto which the laser light is incident, a second optical element disposed downstream of the first optical element in the light propagation direction, and a focusing optical system disposed downstream of the second optical element in the light propagation direction. The beam shaping unit further includes a first focus setting device that controls the first optical element using a linear motor or the like, and a second focus setting device that controls the second optical element. In Patent Document 1, in a casing incorporating the beam shaping unit, the laser light passes through the first optical element controlled by the first focus setting device, passes through an intermediate focus, and is imaged onto the second optical element controlled by the second focus setting device.

[0003] Japanese Patent Application Laid-Open No. 2015-205346

[0004] The present disclosure provides an optical unit, a laser processing apparatus, and a lens barrel that can facilitate zooming of laser light in a laser processing apparatus.

[0005] In the present disclosure, the optical unit includes a laser processing device and includes a plurality of lens groups arranged between an incident side and an exit side in an optical axis direction that guides laser light; a housing having an entrance on the incident side and an exit on the exit side in the optical axis direction and accommodating the plurality of lens groups; a first holding unit that holds a first lens group arranged on the exit side of the plurality of lens groups in the housing; and a first drive unit that drives the first holding unit between a position in the optical axis direction where the first lens group is extended from the exit port of the housing to the exit side and a position on the incident side of the extended position.

[0006] In the present disclosure, a laser processing apparatus includes the above-described optical unit and a laser light source that generates laser light and supplies it to the optical unit.

[0007] In the present disclosure, the lens barrel has an entrance opening provided on the entrance side and an exit opening provided on the exit side in the optical axis direction for guiding laser light in a laser processing device, and is equipped with a housing that houses a plurality of lens groups arranged between the entrance side and the exit side in the optical axis direction, a first holding unit that holds a first lens group arranged on the exit side of the plurality of lens groups in the housing, and a first driving unit that drives the first holding unit between a position where the first lens group is extended from the exit opening of the housing to the exit side in the optical axis direction and a position on the entrance side of the extended position.

[0008] The optical unit, laser processing apparatus, and lens barrel according to the present disclosure can facilitate zooming of laser light in the laser processing apparatus.

[0009] FIG. 1 is a diagram illustrating a configuration of a laser processing device according to a first embodiment of the present disclosure; FIG. 2 is a perspective view illustrating an external appearance of a laser processing head in the first embodiment; FIG. 3 is a cross-sectional view illustrating a configuration example of a laser processing head in the first embodiment; FIG. 4 is a diagram illustrating an example of a zoom operation of a laser processing head in the first embodiment; FIG. 5 is a diagram illustrating a spot of laser light by the laser processing head in the first embodiment;

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0011] The inventor(s) provide the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and do not intend for them to limit the subject matter described in the claims.

[0012] First Embodiment Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. In this embodiment, a laser processing device using a laser processing head, which is an example of an optical unit, will be described.

[0013] 1. Configuration 1.1. Regarding the Laser Processing Apparatus The configuration of the laser processing apparatus according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing the configuration of the laser processing apparatus 1 according to this embodiment.

[0014] 1, the laser processing apparatus 1 includes a laser processing head 2, a laser light source 10, a transmission optical system 11, and a controller 12. The laser processing apparatus 1 is an apparatus that performs laser processing by irradiating various workpieces 15 with laser light LB from the laser processing head 2. The laser processing includes, for example, hardening, welding, cutting, or drilling.

[0015] The laser light source 10 is a light source device that generates laser light LB outputted, for example, in the laser processing apparatus 1. The laser light LB from the laser light source 10 has a resonance wavelength in, for example, the blue region, the near-infrared region, or another wavelength region. The laser light source 10 includes, for example, a direct diode laser. The laser light source 10 may be a wavelength combining type that combines multiple light beams by resonating them at their respective wavelengths, or may be a spatial combining type.

[0016] The transmission optical system 11 is an optical system that transmits the laser light LB from the laser light source 10 to the laser processing head 2. The transmission optical system 11 includes, for example, an optical fiber.

[0017] The laser processing head 2 is a device that is disposed, for example, opposite the workpiece 15 and guides the laser beam LB transmitted from the laser light source 10 to the workpiece 15. In the following, the optical axis direction in which the laser processing head 2 guides the laser beam LB is defined as the Z direction, the direction perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to the Z direction and the Z direction is defined as the Y direction. The orthogonal angles between the various directions do not have to be strictly 90 degrees, and may have an appropriate allowable angular range of error (for example, ±5 degrees).

[0018] The laser processing head 2 of this embodiment has the function of zooming the laser light LB that is irradiated onto the workpiece 15. Zooming the laser processing head 2 makes it possible to adjust, for example, the shape of the spot formed by the laser light LB on the workpiece 15, which is useful for hardening the workpiece 15 or various other precision laser processing operations. In this embodiment, a laser processing head 2 that can zoom in both the X and Y directions will be described. The laser processing head 2 is an example of an optical unit in this embodiment. The laser processing head 2 can be attached to, for example, a robot arm (not shown) and used.

[0019] The controller 12 is a control device that controls the overall operation of the laser processing apparatus 1. The controller 12 includes, for example, a CPU or MPU that works in cooperation with software to realize predetermined functions. The controller 12 may include an internal memory that stores various programs and data, and various interfaces that allow the user to input oscillation conditions and the like. The controller 12 may also include hardware circuits such as an ASIC or FPGA that realize various functions. The controller 12 may also be configured integrally with a drive circuit for the light source.

[0020] 1.2. Laser Processing Head The configuration of the laser processing head 2 in the laser processing device 1 of this embodiment will be described in detail with reference to FIGS. 2 and 3.

[0021] Fig. 2 is a perspective view illustrating an example of the appearance of the laser processing head 2 in this embodiment. Fig. 3 is a cross-sectional view illustrating an example of the configuration of the laser processing head 2 in this embodiment.

[0022] 2, the laser processing head 2 of this embodiment includes a zoom optical system 20 and a lens barrel 3. The zoom optical system 20 is an optical system having a variable focal length for zooming the laser light LB in the laser processing apparatus 1. The lens barrel 3 is a module that constitutes the exterior of the zoom optical system 20 together with a mechanism for realizing zooming in the laser processing head 2.

[0023] The laser processing head 2 of this embodiment is provided with a movable mechanism in the lens barrel 3 that extends a portion of the zoom optical system 20 from the housing 30 to the emission side (+Z side). This makes it easy to change the overall length of the zoom optical system 20 and the lens barrel 3 in the laser processing head 2 in response to zooming, thereby ensuring a large movable range for adjusting the focal length of the zoom optical system 20, etc.

[0024] For example, the beam shaping unit of Patent Document 1 drives first and second optical elements that face each other through an intermediate focus inside a casing, and ensuring this driving range requires a long overall length of the casing. Such conventional laser processing heads have a problem in that the reflected light of the laser light irradiated onto the workpiece 15 is incident on a portion of the casing near the workpiece 15, resulting in excessive heat generation.

[0025] In contrast, with the laser processing head 2 of this embodiment, a mechanism that can extend the zoom optical system 20 from the housing 30 can reduce the area on the laser processing head 2 onto which the reflected light of the laser light LB enters, thereby reducing the effects of heat generation due to the reflected light.

[0026] Figure 3 shows a schematic configuration example of the laser processing head 2, corresponding to the YZ cross section of Figure 2. In the laser processing apparatus 1 of this embodiment, the zoom optical system 20 includes a plurality of lens groups 21 to 24 arranged in the Z direction along the optical axis that guides the laser beam LB. Each of the lens groups 21 to 24 includes, for example, one or more lens elements.

[0027] In this embodiment, an example configuration will be described in which the multiple lens groups 21-24 in the zoom optical system 20 of the laser processing head 2 are made up of first to third movable groups 21-23 and a fixed group 24, as shown in Fig. 3. The first to third movable groups 21-23 are arranged in order from the emission side (+Z side) to the incidence side (-Z side) of the laser light LB. The fixed group 24 is arranged closer to the incidence side than the third movable group 23.

[0028] The laser processing head 2 of this embodiment includes, as the lens barrel 3 of the zoom optical system 20, a housing 30, holding units 41-43, arm units 51-53, and drive units 61-63 provided corresponding to each of the movable groups 21-23, and a fixed unit 40 provided corresponding to the fixed group 24. The drive units 61-63 include arm units 51-53 connected to the holding units 41-43 of the corresponding movable groups 21-23, respectively.

[0029] The housing 30 has, for example, a substantially rectangular parallelepiped cylindrical shape and extends in the Z direction. The housing 30 has an entrance 30a provided on the −Z side and an exit 30b provided on the +Z side. The length of the housing 30 in the Z direction corresponds to the shortest overall length of the variable overall length of the zoom optical system 20.

[0030] Incident port 30a of housing 30 is configured by covering the end of the cylindrical housing 30 on the -Z side with a lid member having an opening for connecting, for example, the optical fiber of transmission optical system 11. Incident port 30a may be configured integrally with the optical fiber. Exit port 30b is an opening into which holding portion 41 of first movable group 21 fits, and is configured by opening the +Z side surface of housing 30, for example.

[0031] 3, the housing 30 has slits 31 to 33 corresponding to the ranges in which the movable groups 21 to 23 can be driven. The slits 31 to 33 for the movable groups 21 to 23 extend along the Z direction on each of the side surfaces of the housing 30 on the -Y, +Y, and -X sides. The slits 31 to 33 in the housing 30 may be hole-shaped or notch-shaped.

[0032] The holding portions 41 to 43 are support members provided inside the housing 30 to drivably hold the movable groups 21 to 23 of the zoom optical system 20. The fixed portion 40 is a support member that fixes the fixed group 24 inside the housing 30. The fixed portion 40 may be configured integrally with the housing 30 or the fixed group 24.

[0033] Each of the arm portions 51 to 53 is an example of a connecting portion extending between the corresponding holding portion 41 to 43 and the driving portion 61 to 63. Each of the driving portions 61 to 63 is a driving mechanism that drives the corresponding movable group 21 to 23 by, for example, moving the holding portion 41 to 43 connected via the arm portion 51 to 53. Each of the driving portions 61 to 63 includes, for example, a ball screw to which the arm portion 51 to 53 is connected, and a motor or actuator that rotates the ball screw.

[0034] 1.2.1. Regarding the barrel mechanism In the laser processing head 2 of this embodiment, the slit 31 in the housing 30 for the first movable group 21, the holding unit 41, and the drive unit 61 constitute a movable mechanism that extends the first movable group 21 of the zoom optical system 20.

[0035] The holder 41 of the first movable group 21 has, for example, a substantially rectangular parallelepiped cylindrical shape with a size equal to or smaller than the size of the inner circumference of the housing 30, and the first movable group 21 is attached near the end on the +Z side. For example, the optical element in the first movable group 21 that is closest to the +Z side is fixed to the end on the +Z side of the holder 41.

[0036] 3, slit 31 for first movable group 21 and drive unit 61 are arranged on the -Y side surface of housing 30. One end of arm unit 51 for first movable group 21 is attached to, for example, the ball screw of drive unit 61, and is inserted through slit 31 on the -Y side of housing 30. The other end of arm unit 51 is attached, for example, near the end of holder 41 on the -Z side.

[0037] The driver 61 of the first movable group 21 drives the holder 41 together with the first movable group 21 by moving the arm 51 within the range of the slit 31 of the housing 30 in the Z direction, for example. The range of the slit 31 of the housing 30 is set to extend to the +Z side from the position of the arm 51 where the holder 41 of the first movable group 21 is entirely housed inside the housing 30 (see FIG. 4A). With the configuration of the laser processing head 2 of this embodiment, the holder 41 of the first movable group 21 can be extended to the +Z side from the housing 30 by driving the driver 61 (see FIG. 4B).

[0038] In the laser processing head 2 of this embodiment, the −Z side end of the holding portion 41 of the first movable group 21 is, for example, open. Slits 41a and 41b that overlap with the slits 32 and 33 for the second and third movable groups 22 and 23 in the housing 30 are provided in the holding portion 41, for example, in a notched shape from the −Z side end, on the +Y side and −X side, respectively.

[0039] The holder 42 of the second movable group 22 is disposed on the -Z side of the holder 41 of the first movable group 21 inside the housing 30, and has, for example, a cylindrical or frame shape with a size equal to or smaller than the size of the inner periphery of the holder 41. The laser processing head 2 of this embodiment is configured so that the holder 42 can enter the holder 41 of the first movable group 21 from the -Z side, for example. This ensures a wide movable range for the second movable group 22.

[0040] 3, a slit 32 for the second movable group 22 and a drive unit 62 are arranged on the +Y side surface of the housing 30. One end of an arm unit 52 for the second movable group 22 is attached to, for example, a ball screw of the drive unit 62, and is inserted through the slit 32 on the +Y side of the housing 30. The other end of the arm unit 52 is attached to, for example, the vicinity of the end of the holding unit 42 on the -Z side.

[0041] The driver 62 of the second movable group 22 drives the holder 42 together with the second movable group 22, for example, by moving the arm 52 on the −Z side of the first movable group 21 within the range of the slit 32 of the housing 30 in the Z direction. At this time, the slit 41a of the holder 41 of the first movable group 21 reduces interference in driving between the first and second movable groups 21, 22, and the movable range of the second movable group 22 can be obtained up to the inside of the holder 41.

[0042] The range of the slit 32 for the second movable group 22 in the housing 30 includes, for example, the position of the arm portion 52 that causes the second movable group 22 to be adjacent to the first movable group 21 when the holding portion 41 of the first movable group 21 is housed inside the housing 30 (see FIG. 4A). The slit 41a for the second movable group 22 in the holding portion 41 of the first movable group 21 is set in a range where the slit 32 of the housing 30 partially or entirely overlaps with the slit 41a when the holding portion 41 is housed inside the housing 30.

[0043] The holder 43 of the third movable group 23 is disposed on the -Z side of the holder 42 of the second movable group 22 inside the housing 30, and has, for example, a frame shape or a cylindrical shape with a size equal to or smaller than the size of the inner periphery of the holder 41 of the first movable group 21. The laser processing head 2 of this embodiment is configured so that the holder 43 can enter the holder 43 of the first movable group 21 from the -Z side, following the holder 42 of the second movable group 22, for example. This ensures a wide movable range for the third movable group 23.

[0044] In this configuration example, a slit 33 ( FIG. 3 ) for the third movable group 23 and a drive unit 63 ( FIG. 2 ) are arranged on the −X side surface of the housing 30. One end of an arm unit 53 for the third movable group 23 is attached to, for example, a ball screw of the drive unit 62, and is inserted through the slit 33 on the −X side of the housing 30. The other end of the arm unit 53 is attached to the holder 43.

[0045] The driver 63 of the third movable group 23 drives the holder 43 together with the third movable group 23, for example, by moving the arm 53 on the −Z side of the second movable group 22 within the range of the slit 33 of the housing 30 in the Z direction. At this time, the slit 41b of the holder 41 of the first movable group 21 reduces drive interference between the first and third movable groups 21, 23, and the movable range of the third movable group 23 can be obtained up to the inside of the holder 41.

[0046] The range of the slit 33 for the third movable group 23 in the housing 30 is set, for example, to the positional range of the arm portion 53 that moves the third movable group 23 between the second movable group 22 and the fixed group 24 in a state in which the first movable group 21 is extended from the housing 30 (see FIGS. 4(B) and 4(B)). The slit 41b for the third movable group 23 in the holder 41 of the first movable group 21 is set, for example, to a range in which the slit 33 of the housing 30 overlaps with the slit 41b in a state in which the holder 41 is housed inside the housing 30.

[0047] 1.2.2. Zoom Optical System A detailed configuration example of the zoom optical system 20 in the laser processing head 2 of this embodiment will be described below.

[0048] The first movable group 21 includes a lens element having positive power (refractive power) in the X direction, for example. The lens element of the first movable group 21 is, for example, a cylindrical lens having no power in the Y direction. The first movable group 21 may include optical elements other than lens elements. For example, a cover glass having no power may be disposed on the most +Z side of the first movable group 21.

[0049] The second movable group 22 includes a lens element such as a cylindrical lens having negative power in the X direction and no power in the Y direction. The cylindrical lens of the second movable group 22 may be a plano-concave lens having a flat surface on the -Z side and a concave surface on the +Z side. In addition to the lens element, the second movable group 22 may also include an optical element such as a microlens array.

[0050] The third movable group 23 includes a lens element such as a cylindrical lens having positive power in the Y direction and no power in the X direction. The third movable group 23 may be composed of one lens element, may include multiple lens elements, or may include other optical elements.

[0051] The fixed group 24 includes lens elements such as a negative lens arranged on the +Z side and a collimator lens arranged on the −Z side. The negative lens of the fixed group 24 is, for example, a cylindrical lens that has negative power in the Y direction and no power in the X direction. The cylindrical lens may be a plano-concave lens that has a flat surface on the −Z side.

[0052] The collimator lens of the fixed group 24 has, for example, a rotationally symmetric surface shape and has positive power for collimating the laser light LB incident from the entrance 30a of the housing 30. For example, the central axis of the collimator lens defines the optical axis of the zoom optical system 20. The fixed group 24 may include a plurality of lens elements or other optical elements.

[0053] 2. Operation The operation of the laser processing device 1 and its laser processing head 2 configured as above will be described below.

[0054] The laser processing apparatus 1 (FIG. 1) of this embodiment drives the laser light source 10 based on oscillation conditions set in, for example, a controller 12, causing the laser light source 10 to generate laser light LB. The laser processing apparatus 1 performs various types of laser processing by irradiating the laser light LB generated by the laser light source 10 from the laser processing head 2 to an object to be processed 15 under the control of, for example, the controller 12.

[0055] In the laser processing apparatus 1 as described above, the laser processing head 2 of this embodiment operates the zoom optical system 20 to zoom the laser light LB, for example, under the control of the controller 12 .

[0056] The zoom operation of the laser processing head 2 of this embodiment can adjust the shape of the spot of the laser light LB, etc., using the power in the X and Y directions in the zoom optical system 20. The configuration of the laser processing head 2 of this embodiment can ensure a wide variable range of the focal length in the X and Y directions during such zoom operation.

[0057] 2.1 Zooming Operation The zooming operation of the laser processing head 2 in this embodiment will be described with reference to Figures 4 to 6. Figure 4 shows an example of the zooming operation of the laser processing head 2 in this embodiment. Figure 5 shows an example of the spot Ls of the laser light LB emitted by the laser processing head 2.

[0058] 4A illustrates an example of a first mode in the zoom operation of the laser processing head 2. In this embodiment, in the first mode of the laser processing head 2, as illustrated in FIG. 4A, the holder 41 of the first movable group 21 is housed inside the housing 30, and the first movable group 21 is positioned on the -Z side within the driving range of the drive unit 61. In this example, the third movable group 23 is positioned on the +Z side within that driving range. The second movable group 22 is adjacent to the first and third movable groups 21 and 23, for example.

[0059] 5A illustrates an example of a spot Ls formed by the laser processing head 2 in the first mode (FIG. 4A). The laser processing head 2 of this embodiment forms a rectangular spot Ls on the workpiece 15 by irradiating it with laser light LB. The laser processing head 2 of this embodiment controls the X-direction focal length and Y-direction focal length of the zoom optical system 20 by zooming, thereby changing the X-direction width Lx and Y-direction width Ly of the spot Ls.

[0060] For example, in the zoom optical system 20 of this embodiment, because the first and second movable groups 21 and 22 have power in the X direction, the focal length of the zoom optical system 20 in the X direction can be controlled according to the distance between the first and second movable groups 21 and 22. Also, the focal length of the zoom optical system 20 in the Y direction can be controlled according to the distance between the third movable group 23, which has power in the Y direction, and the fixed group 24. Furthermore, the positional relationship between the focal position in the X direction and the focal position in the Y direction in the zoom optical system 20 can be controlled according to the distance between the second and third movable groups 22 and 23.

[0061] 4(B) illustrates the second mode of the laser processing head 2. In the second mode of this embodiment, as illustrated in FIG. 4(B), the holder 41 of the first movable group 21 is extended from the housing 30, and the first movable group 21 is positioned on the +Z side within its driving range. In this example, the third movable group 23 is positioned on the -Z side within its driving range. The second movable group 22 is appropriately positioned within its driving range.

[0062] 5B illustrates the spot Ls formed by the laser processing head 2 in the second mode (FIG. 4B). The laser processing head 2 of this embodiment widens the distance between the first and second movable groups 21, 22, as shown in FIGS. 4A and 4B, for example, during a zoom operation to transition from the first mode to the second mode.

[0063] The zoom operation described above shortens the focal length in the X direction in the zoom optical system 20 of this configuration example because the first and second movable groups 21 and 22 have powers of opposite signs in the X direction. Zooming out in the X direction in this manner allows Fourier transform imaging of the zoom optical system 20 to make the width Lx of the spot Ls in the X direction smaller in the second mode than in the first mode, as illustrated in FIGS.

[0064] 4A and 4B, the laser processing head 2 of this embodiment narrows the distance between the third movable group 23 and the fixed group 24 during zooming from the first mode to the second mode, for example. This zooming operation extends the focal length in the Y direction of the zoom optical system 20 of this configuration example because the negative lenses of the third movable group 23 and the fixed group 24 have powers of opposite signs in the Y direction. This zooming in in the Y direction makes it possible to increase the Y-direction width Ly of the spot Ls in the second mode compared to the first mode.

[0065] In the laser processing head 2 of this embodiment, when transitioning between the first and second modes as described above, the movement of each of the movable groups 21 to 23 is appropriately synchronously controlled, thereby enabling zooming so as to maintain the area of ​​the spot Ls of the laser light LB. Furthermore, the zooming operation of the laser processing head 2 of this embodiment is not limited to the above, and the movement of each of the movable groups 21 to 23 may be controlled independently.

[0066] 6A and 6B show another example of the zoom operation of the laser processing head 2 in this embodiment. Fig. 6A illustrates a third mode of the laser processing head 2. Fig. 6B illustrates a fourth mode of the laser processing head 2.

[0067] 6A, the third mode of the laser processing head 2 is, for example, arranged with the first movable group 21 on the -Z side as in the first mode (FIG. 4A), and the third movable group 23 on the -Z side as in the second mode (FIG. 4B). The third mode has a relatively long focal length in both the X and Y directions, for example, and the spot Ls has a relatively large width in both directions.

[0068] 6B, the fourth mode of the laser processing head 2 is, for example, similar to the second mode (FIG. 4B), in which the second movable group 21 is arranged on the +Z side, and similar to the first mode (FIG. 4A), in which the third movable group 23 is arranged on the +Z side. The fourth mode has a relatively short focal length in both the X and Y directions, for example, and the spot Ls has a relatively small width in both directions.

[0069] 6A and 6B, in a zoom operation for transitioning from the third mode to the fourth mode, the laser processing head 2 of this embodiment zooms out in the X direction and also zooms out in the Y direction by moving the third movable group 23 toward the +Z side. By such a zoom operation between the third and fourth modes, the laser processing head 2 of this embodiment can change, for example, the size of the spot Ls.

[0070] The laser processing head 2 of this embodiment can perform a zoom operation to change between the first to fourth modes as described above. For example, the laser processing head 2 may transition from the second mode (FIG. 4B) to the third mode (FIG. 6A) by zooming in to extend the focal length in the X direction by narrowing the spacing between the first and second movable groups 21, 22. The laser processing head 2 of this embodiment can also be used in various intermediate states between the first to fourth modes.

[0071] 3. Summary As described above, the laser processing head 2, which is an example of an optical unit in this embodiment, includes a plurality of lens groups 21-24, a housing 30, a holder 41, which is an example of a first holder, and a driver 61, which is an example of a first driver. The plurality of lens groups 21-24 are arranged between an incident side and an exit side in the Z direction, which is an example of an optical axis direction for guiding the laser light LB in the laser processing device 1. The housing 30 has an entrance 30a on the incident side and an exit 30b on the exit side in the Z direction, and houses the plurality of lens groups 21-24. The holder 41 holds the first movable group 21, which is an example of a first lens group and is arranged on the exit side of the plurality of lens groups 21-24 in the housing 30. The drive unit 61 drives the holding unit 41 between a position in the Z direction where the first movable group 21 is extended from the exit port 30b of the housing 30 to the emission side (see Figure 4(B)) and a position on the incidence side of the extended position (see Figure 4(A)).

[0072] With the above-described laser processing head 2, the first movable group 21 of the plurality of lens groups 21 to 24 can be extended further to the +Z side than the exit port 31b of the housing 30, ensuring a wide driving range for the first movable group 21 and the like during zooming of the laser processing head 2. Thus, with the laser processing head 2 of this embodiment, zooming of the laser light LB can be easily performed in the laser processing device 1.

[0073] In the laser processing head 2 of this embodiment, the multiple lens groups 21 to 24 include, for example, a third movable group 23 as an example of a second lens group. For example, the laser processing head 2 further includes a holder 43 and a driver 63 for the third movable group 23 as examples of a second holder and a second driver, respectively. The third movable group 23 is disposed on the incident side of the first movable group 21 in the zoom optical system 20. The holder 43 for the third movable group 23 holds the third movable group 23 of the multiple lens groups 21 to 24 in the housing 30. The driver 63 for the third movable group 23 drives the holder 43 on the incident side of the first movable group 21 in the Z direction.

[0074] With these multiple movable groups 21, 22, the laser processing head 2 of this embodiment can facilitate zooming of the laser light LB in the laser processing apparatus 1. The second lens group of this embodiment is not limited to the above example. In the laser processing head 2 of this embodiment, the second movable group 22 may be an example of the second lens group, and the holder 42 and driver 62 of the second movable group 22 may be an example of the second holder and second driver, respectively.

[0075] In the laser processing head 2 of this embodiment, the drive units 62, 63 include arm units 52, 53, which are an example of a coupling unit, that are coupled to the holders 42, 43, respectively. The housing 30 has slits 32, 33, which are an example of a first gap, through which the arm units 52, 53 pass and which define the drive ranges of the drive units 62, 63. The holder 41 has slits 41a, 41b, which are an example of a second gap, that overlap with the slits 32, 33 when the first movable group 21 is in the incident side position. This allows the movable groups 21-23 to be spaced closer to each other, ensuring a wide variable range of zoom operation and facilitating zooming of the laser light LB.

[0076] The laser processing head 2 of this embodiment has a first mode in which the holder 41 of the first movable group 21 is in a position on the incident side and the second holder is in a position on the output side within the driving range of the second drive unit (see FIG. 4A). The laser processing head 2 of this embodiment has a second mode in which the holder 41 of the first movable group 21 is in a position to be extended and the second holder is in a position on the incident side within the driving range of the second drive unit (see FIG. 4B). As in these first and second modes, the laser processing head 2 of this embodiment can change the distance between the first and second lens groups over a wide range, which makes it easier to zoom the laser light LB.

[0077] The laser processing head 2 of this embodiment has a third mode in which the holder 41 of the first movable group 21 is in a position on the incident side, and the second holder is on the incident side within the drive range of the second drive unit (see FIG. 4A). The laser processing head 2 of this embodiment has a fourth mode in which the holder 41 of the first movable group 21 is in a position to be extended, and the second holder is on the output side within the drive range of the second drive unit (see FIG. 4B). As in these various modes, the laser processing head 2 of this embodiment can drive the various movable groups 21 to 23 in various ways, making it easy to zoom the laser light LB.

[0078] In the laser processing head 2 of this embodiment, the first movable group 21 has stronger power in the X direction, which is an example of a first direction perpendicular to the Z direction, than in the Y direction, which is an example of a second direction perpendicular to the Z and X directions. The first movable group 21 enables the laser processing head 2 of this embodiment to achieve rotationally asymmetric zooming, such as adjusting the focal length of the laser beam LB in the X direction, making it easier to zoom the laser beam LB. The strength of the power is defined, for example, by the absolute value of the power, regardless of the sign of the power.

[0079] In the laser processing head 2 of this embodiment, the third movable group 23, which is an example of the second lens group, may have a stronger power in the Y direction than in the X direction. This allows the laser processing head 2 of this embodiment to perform zooming in separate directions, such as the X and Y directions, and to adjust the shape of the spot Ls of the laser light LB, for example. The second lens group may have a power in at least one of the X and Y directions.

[0080] In the laser processing head 2 of this embodiment, the multiple lens groups 21-24 may include a second movable group 22 as an example of a third lens group disposed between the first movable group 21 and the third movable group 23. For example, the laser processing head 2 further includes a holder 42 and a driver 62 for the second movable group 22 as examples of a third holder and a third driver. The holder 42 for the second movable group 22 holds the second movable group 22 of the multiple lens groups 21-24 in the housing 30. The driver 62 for the second movable group 22 drives the holder 42 in the Z direction. The second movable group 22 may have stronger power in the X direction than in the Y direction. With the laser processing head 2 of this embodiment, the focal length in the X direction can be adjusted according to the distance between the first and second movable groups 21 and 22, and the focus in the X and Y directions can be adjusted according to the distance between the second and third movable groups 22 and 23, making it easier to zoom the laser light LB. The third lens group may have the same power in the X direction and the Y direction, or may have a stronger power in the Y direction than in the X direction.

[0081] In the laser processing head 2 of this embodiment, the second movable group 22 may have a stronger power in the X direction than in the Y direction. The power of the first movable group 21 and the power of the second movable group 22 may have opposite signs, i.e., opposite positive and negative. This makes it possible to achieve zooming out / in in the X direction by widening or narrowing the gap between the first and second movable groups 21, 22, and makes it easier to zoom the laser light LB.

[0082] In the laser processing head 2 of this embodiment, the multiple lens groups 21 to 24 further include a fixed group 24, which is an example of a fourth lens group and is arranged closer to the incident side than the third movable group 23 and has power in at least one of the X and Y directions. The fixed group 24 may include a lens having a stronger power in the Y direction than in the X direction. This allows zooming in the Y direction to be performed depending on the distance from the fixed group 24 to the third movable group 23. The fixed group 24 may also include a collimator lens that collimates the laser light LB from the entrance 30a. Such a fixed group 24 makes it easier to zoom the laser light LB.

[0083] In the laser processing head 2 of this embodiment, the various drive units 61 to 63 are arranged on the side of the housing 30. This makes it possible to prevent the overall length of the housing 30 from becoming too large when securing the movable range of the zoom operation using the drive units 61 to 63 in the laser processing head 2.

[0084] In the laser processing head 2 of this embodiment, the first movable group 21 is held on the emission side of the holding portion 41. This makes it possible to limit the area where reflected light from the workpiece 15 enters the laser processing head 2 when laser light LB is irradiated from the laser processing head 2 to the workpiece 15. This makes it possible to reduce the influence of heat generation due to reflected light in the laser processing head 2 that can perform zoom operations.

[0085] In the laser processing head 2 of this embodiment, the multiple lens groups 21-24 are configured as a zoom optical system 20 to change the shape of the spot Ls formed by irradiation with the laser light LB in response to driving of the drive unit 61, etc. For example, the ratio between the width Lx in the X direction and the width Ly in the Y direction of the spot Ls, i.e., the aspect ratio, can be changed. For example, the zoom optical system 20 of this embodiment can increase the widths Lx and Ly of the spot Ls in the corresponding direction by extending the focal lengths of the multiple lens groups 21-24 in the X direction or Y direction. The laser processing head 2 of this embodiment can use the zoom optical system 20 to change the ratio between the width Lx in the X direction and the width Ly in the Y direction of the spot Ls, i.e., the aspect ratio, and to change the beam profile indicating the distribution of light intensity in the spot Ls, thereby facilitating various zooming operations of the laser light LB.

[0086] In this embodiment, the laser processing apparatus 1 includes a laser processing head 2 and a laser beam LB source that generates laser beam LB and supplies it to the laser processing head 2. In the laser processing head 2 of this embodiment, the configuration of the laser processing head 2 makes it easy to zoom the laser beam LB.

[0087] In this embodiment, the lens barrel 3 has an entrance 30a provided on the entrance side and an exit 30b provided on the exit side in the Z direction along which the laser beam LB is guided in the laser processing device 1, and includes a housing 30 that houses a plurality of lens groups 21-24 arranged between the entrance side and the exit side in the Z direction, a holder 41 that holds a first movable group 21 arranged on the exit side of the plurality of lens groups 21-24 in the housing 30, and a drive unit 61 that drives the holder 41 between a position where the holder 41 extends from the exit opening 30b of the housing 30 to the exit side in the Z direction and a position closer to the entrance side than the extended position. Such a lens barrel 3 realizes a mechanism for extending the first movable group 21 from the housing 30 in the laser processing head 2, making it easier to zoom the laser beam LB.

[0088] (Other Embodiments) As described above, embodiment 1 has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, it is also possible to combine the components described in each of the above embodiments to create a new embodiment. Therefore, other embodiments will be described below as examples.

[0089] In the above-described first embodiment, the laser processing head 2 has been described as having the slits 31 to 33, 41a, and 41b in the housing 30 and the holding portion 41, but the slits 31 to 33, 41a, and 41b may be shielded as appropriate. Such a modification will be described with reference to FIG.

[0090] 7 illustrates the configuration of a modified laser processing head 2. The laser processing head 2 of this embodiment has a configuration similar to that of the laser processing head 2 of embodiment 1, and further includes multiple covers 70, 71, and 72. The various covers 70 to 72 are made of a light-blocking material that does not transmit light in the wavelength range of the laser light LB, for example.

[0091] The cover 70 shields the slit 41 a for the second movable group 22 in the holder 41 of the first movable group 21. The cover 70 is configured, for example, by a bellows structure, so that the length between the end of the slit 41 a on the +Z side and the emission opening 30 b of the housing 30 is variable. In this modified example, similar to the cover 70, a cover may be provided that shields the slit 41 b for the third movable group 23 in the holder 41 of the first movable group 21.

[0092] Cover 71 covers slit 31 on the +Y side of housing 30. Cover 72 covers slit 32 on the −Y side of housing 30. In this modification, similar to covers 71 and 72, a cover that covers slit 33 on the −X side of housing 30 may be provided.

[0093] In the laser processing head 2 of this embodiment, these covers 70 to 72 can protect the slits 31 to 33, 41a, and 41b from dust or suppress leakage of the laser light LB.

[0094] As described above, the laser processing head 2 of the present embodiment may include the cover 72 that covers the slit 32, which is an example of the first gap, or the cover 70 that covers the slit 41a, which is an example of the second gap. This provides dust protection or light shielding to the laser processing head 2 having a movable zooming mechanism, making it easier to zoom the laser light LB.

[0095] In each of the above embodiments, the laser processing head 2 has been described as having three movable groups 21-23. In the laser processing head 2 of the present embodiment, the number of movable groups 21-23 is not particularly limited to three, and may be one or two, or may be four or more. For example, in the laser processing head 2 of the present embodiment, one or both of the second movable group 22 and the third movable group 23 may be omitted in the zoom optical system 20 similar to that of embodiment 1. With the laser processing head 2 of the present embodiment, zooming of the laser light LB can also be facilitated, as in the above embodiments, by using a mechanism that extends the first movable group 21 from the housing 30.

[0096] Furthermore, in each of the above embodiments, exemplary configurations of the zoom optical system 20 and the corresponding lens barrel 3 have been described. The laser processing head 2 of this embodiment is not limited to the above exemplary configurations, and various configurations of the zoom optical system 20 and the corresponding lens barrel 3 can be employed. For example, in the zoom optical system 20 of this embodiment, the positive and negative powers of the various lens groups 21 to 24 are not limited to the above exemplary configurations. For example, the first movable group 21 may have negative power, and the second movable group 22 may have positive power. Furthermore, the powers of the first and second movable groups 21, 22 may have the same sign. Similarly, various powers may be used for the other lens groups 23, 24.

[0097] In addition, in each of the above embodiments, an example has been described in which cylindrical lenses are used for the various lens groups 21 to 24 of the zoom optical system 20. In the zoom optical system 20 of this embodiment, various rotationally asymmetric lenses, such as free-form lenses, may be used instead of cylindrical lenses. This also makes it possible to achieve separate zooming in the X and Y directions in the laser processing head 2 of this embodiment.

[0098] Furthermore, the zoom optical system 20 of this embodiment is not limited to rotationally asymmetric lenses, and rotationally symmetric lenses may also be used. The laser processing head 2 of this embodiment may perform rotationally symmetric zooming rather than separate zooming in the X and Y directions. Even in this case, the laser processing head 2 of this embodiment can easily perform zooming of the laser light LB, as in the above embodiments, by using a mechanism for extending the first movable group 21.

[0099] Furthermore, in each of the above embodiments, the laser processing head 2 has been described in which the holding portion 41 of the first movable group 21 can be entirely housed in the housing 30. In the laser processing head 2 of this embodiment, the holding portion 41 of the first movable group 21 does not have to be entirely housed in the housing 30, and a portion of the holding portion 41 may protrude from the exit port 30b of the housing 30 at the position on the most incident side. In this case, a portion or the entire first movable group 21 held by the holding portion 41 may be outside the range of the housing 30. In the laser processing head 2 of this embodiment, too, zooming of the laser light LB can be easily performed, as in the above embodiments, by virtue of a configuration in which the first movable group 21 can be driven from the above-described incident side position to a position where it is extended together with the holding portion 41.

[0100] In the above embodiments, the laser processing head 2 has been described as an example of an optical unit. In the present embodiment, the optical unit is not necessarily limited to the laser processing head 2, but may be an optical device that can be used for various purposes of guiding laser light, such as beam shaping, in the laser processing apparatus 1.

[0101] (Examples of Aspects) Various aspects of the present disclosure will be exemplified below.

[0102] A first aspect of the present disclosure is an optical unit comprising: a laser processing device; a housing having an entrance on the entrance side and an exit on the exit side in the optical axis direction for guiding laser light; a housing for accommodating the plurality of lens groups; a first holding unit for holding a first lens group in the housing that is arranged on the exit side among the plurality of lens groups; and a first driving unit for driving the first holding unit between a position where the first lens group is extended from the exit port of the housing to the exit side in the optical axis direction and a position on the entrance side of the extended position.

[0103] In a second aspect, the optical unit described in the first aspect further includes, in the housing, a second holding portion that holds a second lens group among the plurality of lens groups that is arranged on the incident side of the first lens group, and a second driving portion that drives the second holding portion on the incident side of the first lens group in the optical axis direction.

[0104] In a third aspect, in the optical unit according to the second aspect, the second driving unit includes a connecting portion connected to the second holding portion. The housing has a first gap through which the connecting portion is inserted to define a driving range of the second driving unit. The first holding portion has a second gap that overlaps with the first gap when the first lens group is in the incident side position.

[0105] In a fourth aspect, the optical unit according to the third aspect further includes a cover that covers at least one of the first gap and the second gap.

[0106] In a fifth aspect, the optical unit according to any one of the second to fourth aspects has a first mode in which the first holding part is in a position on the incident side and the second holding part is in a position on the output side within the drive range of the second drive part. The optical unit may have a second mode in which the first holding part is in a position to be extended and the second holding part is in a position on the incident side within the drive range of the second drive part.

[0107] In a sixth aspect, the optical unit according to any one of the second to fifth aspects has a third mode in which the first holding part is in a position on the incident side and the second holding part is in a driving range of the second driving part on the incident side. The optical unit may have a fourth mode in which the first holding part is in a position to be extended and the second holding part is in a driving range of the second driving part on the output side.

[0108] In a seventh aspect, in the optical unit according to any one of the first to sixth aspects, the first lens group has a stronger power in a first direction perpendicular to the optical axis direction than in a second direction perpendicular to the optical axis direction and the first direction. In the optical unit according to any one of the second to sixth aspects, the second lens group may have a stronger power in the second direction than in the first direction. Alternatively, the second lens group may have a power in at least one of the first direction and the second direction.

[0109] In an eighth aspect, the optical unit according to any one of the first to seventh aspects further includes, in the housing, a third holder configured to hold a third lens group disposed between the first lens group and the second lens group, and a third drive unit configured to drive the third holder in the optical axis direction. The third lens group may have a stronger power in the first direction than in the second direction.

[0110] In a ninth aspect, in the optical unit described in any of the first to eighth aspects, the plurality of lens groups further includes a fourth lens group that is arranged on the incident side of the second lens group and has power in at least one of the first direction and the second direction.

[0111] In a tenth aspect, in the optical unit according to any one of the first to ninth aspects, the first driving section is disposed on a side surface of the housing.

[0112] In an eleventh aspect, in the optical unit according to any one of the first to tenth aspects, the first lens group is held on the exit side of the first holding portion.

[0113] In a twelfth aspect, in an optical unit described in any of the first to eleventh aspects, the multiple lens groups are configured to change the shape of the spot formed by irradiation with laser light in accordance with the driving of the first driving unit.

[0114] A thirteenth aspect is a laser processing apparatus including the optical unit according to any one of the first to twelfth aspects, and a laser light source that generates laser light and supplies it to the optical unit.

[0115] The fourteenth aspect is a lens barrel comprising: a housing having an entrance opening on the entrance side and an exit opening on the exit side in an optical axis direction for guiding laser light in a laser processing device, and accommodating a plurality of lens groups arranged between the entrance side and the exit side in the optical axis direction; a first holding unit that holds a first lens group arranged on the exit side of the plurality of lens groups in the housing; and a first driving unit that drives the first holding unit between a position where the first lens group is extended from the exit opening of the housing to the exit side in the optical axis direction and a position on the entrance side of the extended position.

[0116] In the present disclosure, the lens barrel according to the fifteenth aspect may constitute the optical unit according to any one of the first to thirteenth aspects. A lens barrel having any of the features of the optical unit according to any one of the first to thirteenth aspects may be provided.

[0117] As described above, the embodiments have been described as examples of the technology in the present disclosure, and for that purpose, the accompanying drawings and detailed description have been provided.

[0118] Therefore, the components shown in the accompanying drawings and detailed description may include not only essential components for solving the problem, but also components that are not essential for solving the problem in order to illustrate the above technology. Therefore, the fact that these non-essential components are shown in the accompanying drawings or detailed description should not be interpreted as immediately indicating that these non-essential components are essential.

[0119] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0120] The present disclosure is applicable to optical units and lens barrels used in, for example, laser processing devices.

Claims

1. An optical unit comprising: a plurality of lens groups arranged between an incident side and an exit side in an optical axis direction along which laser light is guided in a laser processing device; a housing having an entrance opening on the incident side and an exit opening on the exit side in the optical axis direction and accommodating the plurality of lens groups; a first holding unit that holds a first lens group arranged on the exit side of the plurality of lens groups in the housing; and a first driving unit that drives the first holding unit between a position where the first lens group is extended from the exit opening of the housing to the exit side in the optical axis direction and a position closer to the incident side than the extended position.

2. The optical unit according to claim 1, further comprising: a second holding section in the housing that holds a second lens group that is arranged on the incident side of the first lens group among the plurality of lens groups; and a second driving section that drives the second holding section on the incident side of the first lens group in the optical axis direction.

3. An optical unit as described in claim 2, wherein the second drive unit includes a connecting part that connects to the second holding part, the housing has a first gap through which the connecting part is inserted and which defines the drive range of the second drive unit, and the first holding part has a second gap that overlaps with the first gap when the first lens group is in the incident side position.

4. The optical unit according to claim 3, further comprising a cover that covers at least one of the first gap and the second gap.

5. An optical unit as described in claim 2, having a first mode in which the first holding section is at the incident side position and the second holding section is at the output side within the driving range of the second driving section, and a second mode in which the first holding section is at the extended position and the second holding section is at the incident side within the driving range of the second driving section.

6. An optical unit as described in claim 2, having a third mode in which the first holding section is at the incident side position and the second holding section is at the incident side within the driving range of the second driving section, and a fourth mode in which the first holding section is at the extended position and the second holding section is at the exit side within the driving range of the second driving section.

7. The optical unit according to claim 2, wherein the first lens group has a stronger power in a first direction perpendicular to the optical axis direction than in a second direction perpendicular to the optical axis direction and the first direction, and the second lens group has a stronger power in the second direction than in the first direction.

8. The optical unit according to claim 7, further comprising: a third holding section in the housing that holds a third lens group that is arranged between the first lens group and the second lens group among the plurality of lens groups; and a third driving section that drives the third holding section in the optical axis direction.

9. The optical unit according to claim 7, wherein the plurality of lens groups further includes a fourth lens group that is disposed closer to the incident side than the second lens group and has power in at least one of the first direction and the second direction.

10. The optical unit according to claim 1, wherein the first drive unit is disposed on a side surface of the housing.

11. The optical unit according to claim 1, wherein the first lens group is held on the exit side of the first holding portion.

12. The optical unit according to claim 1, wherein the plurality of lens groups are configured to change the shape of the spot formed by irradiation with the laser light in response to driving of the first driving section.

13. A laser processing device comprising: the optical unit according to claim 1; and a laser light source that generates laser light and supplies it to the optical unit.

14. A lens barrel comprising: a housing for a laser processing device, which has an entrance opening provided on the entrance side and an exit opening provided on the exit side in an optical axis direction for guiding laser light, and which houses a plurality of lens groups arranged between the entrance side and the exit side in the optical axis direction; a first holding unit that holds a first lens group arranged on the exit side of the plurality of lens groups in the housing; and a first driving unit that drives the first holding unit between a position where the first lens group is extended from the exit opening of the housing to the exit side in the optical axis direction and a position on the entrance side of the extended position.

Images