Laser cutting equipment

Abstract

The present application provides a laser cutting device. The laser cutting device includes: a light source part configured to emit a laser beam; a table on which a workpiece is placed; an optical system including a scanning unit configured to irradiate the laser beam to the table and change the irradiation direction of the laser beam along a shape set for the workpiece and an optical device arranged on a path of the laser beam from the light source part to the scanning unit; and an optical path selection part arranged between the light source part and the optical system and configured to adjust the path of the laser beam so that the laser beam moves to one of the optical devices.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and all benefits arising from Korean Patent Application No. 10-2023-0133652, filed on October 6, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to a laser cutting device and a laser cutting method using the laser cutting device. Background Art

[0004] Laser cutting equipment can be used to cut display devices that use, for example, a glass-based substrate as a base substrate to a desired standard.

[0005] Examples of the display device may include an organic light emitting display ("OLED") or a liquid crystal display ("LCD").

[0006] Also, when manufacturing such a display device, a laser cutting device is used to irradiate a laser beam onto a substrate of a product to cut the substrate of the product into a desired size and shape. When the laser beam moves along the shape of the substrate, there must be a portion where the shape changes into a curve, and in this portion, the moving speed of the laser beam changes, that is, an acceleration portion / deceleration portion may occur. Summary of the invention

[0007] The present disclosure provides a laser cutting apparatus that can switch a workpiece from straight-line processing to curved-line processing without reducing a driving speed of a scanning unit.

[0008] According to an embodiment of the present invention, the laser cutting equipment includes: a light source part configured to emit a laser beam; a table on which a workpiece is placed; an optical system including a scanning unit configured to irradiate the laser beam to the table and change the irradiation direction of the laser beam along a shape set for the workpiece, and an optical device arranged on a path of the laser beam from the light source part to the scanning unit; and an optical path selection part arranged between the light source part and the optical system and configured to adjust the path of the laser beam so that the laser beam moves to one of the optical devices.

[0009] The optical device may include a first optical device and a second optical device, each of which has a diffraction portion configured to convert an incident laser beam into polarized light, and the diffraction portion may have a diffraction pattern that selects a vibration direction of the polarized light.

[0010] The diffraction pattern of the diffraction part of the first optical device and the diffraction pattern of the diffraction part of the second optical device may be different from each other in a stationary state.

[0011] Compared to the diffraction pattern of the diffraction part of the first optical device, the diffraction pattern of the diffraction part of the second optical device may be tilted in a direction opposite to a rotation direction in which the diffraction part of the second optical device rotates in a stationary state.

[0012] The rotation time of the diffractive part of the first optics and the rotation time of the diffractive part of the second optics may not at least partially overlap.

[0013] The set shape of the workpiece can have a straight processing part and a curved processing part, and the optical path selection part can adjust the path of the laser beam to be directed to the first optical device during cutting the straight processing part, and adjust the path of the laser beam to be directed to the second optical device during cutting the curved processing part.

[0014] When the laser beam is incident on the first optical device, the diffractive portion of the first optical device may be in a stationary state, and when the laser beam is incident on the second optical device, the diffractive portion of the second optical device may be in a rotating state.

[0015] The scanning unit can change the path of the laser beam at a constant speed.

[0016] The optical device may further include a third optical device having a diffraction portion configured to convert the incident laser beam into polarized light, the diffraction portion may have a diffraction pattern that selects a vibration direction of the polarized light. The diffraction pattern of the diffraction portion of the first optical device, the diffraction pattern of the diffraction portion of the second optical device, and the diffraction pattern of the diffraction portion of the third optical device may be different from each other in a stationary state.

[0017] The set shape of the workpiece can have a straight processing part and a curved processing part, and the optical path selection part can adjust the path of the laser beam to be directed to the first optical device or the third optical device during cutting the straight processing part, and can adjust the path of the laser beam to be directed to the second optical device during cutting the curved processing part.

[0018] The laser cutting method according to an embodiment of the present invention includes: preparing a workpiece on a stage; emitting a laser beam from a light source, and selectively causing the laser beam to enter a first optical device or a second optical device. The method also includes: cutting the workpiece by a scanning unit to move to the stage along the irradiation direction of the laser beam output from the first optical device or the second optical device in a shape set for the workpiece.

[0019] The selective entry of the laser beam on the first optical device or the second optical device may include adjusting a path of the laser beam from the light source part to the scanning unit through the optical path selection part.

[0020] The shape set for the workpiece may include a straight-line processing portion and a curved-line processing portion. The straight-line processing portion is cut by the laser beam passing through the first optical device, and the curved-line processing portion is cut by the laser beam passing through the second optical device.

[0021] Adjusting the path of the laser beam by the optical path selection part may include: when the diffraction part of the first optical device is in a stationary state, adjusting the path of the laser beam to be directed to the first optical device; and when the diffraction part of the second optical device is in a rotating state, adjusting the path of the laser beam to be directed to the second optical device.

[0022] The vibration direction of the laser beam passing through the first optical device may be parallel to the linear processing portion of the workpiece.

[0023] The vibration direction of the laser beam passing through the second optical device may be rotated, and the vibration direction of the laser beam passing through the second optical device may correspond to a tangent line of a curved line processing portion of the workpiece.

[0024] When the laser beam enters the first optics, the diffractive portion of the second optics may begin to rotate.

[0025] The time required to adjust the path of the laser beam by the optical path selection portion may be equal to or shorter than the time required for the scanning unit to change the irradiation direction of the laser beam.

[0026] When the laser beam enters the second optics, the diffractive portion of the first optics may begin to rotate.

[0027] The straight line processing portion may include a first straight line processing portion and a second straight line processing portion. The first straight line processing portion may be cut by a laser beam passing through the first optical device, and the second straight line processing portion may be cut by a laser beam passing through the third optical device. An extension line of the first straight line processing portion and an extension line of the second straight line processing portion may intersect each other.

[0028] According to an embodiment of the present invention, when the cutting path is switched between a curved processing portion and a straight processing portion on a workpiece, the processing can be performed while maintaining a constant speed of a scanning unit placed in a laser cutting device without slowing down, thereby effectively reducing the cutting process time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a diagram showing a laser cutting apparatus according to one embodiment.

[0030] Figure 2 It is shown in Figure 1 Figure 1. A diagram of a curved portion of a workpiece being cut in a laser cutting device.

[0031] Figure 3 It is shown in Figure 1 FIG. 1 is a diagram of a second straight line processing portion of a workpiece cut in a laser cutting device.

[0032] Figure 4 It is shown in Figure 1 Figure 1. Diagram of a diffractive section in a laser cutting device.

[0033] Figure 5 is a flow chart illustrating a laser cutting method according to one embodiment.

[0034] Figure 6 is a graph showing directions of a diffraction pattern of a diffraction part according to process time.

[0035] Figure 7 is a graph comparing laser cutting using a single optical device and laser cutting using multiple optical devices according to the present embodiment.

[0036] Figure 8 is a diagram showing a laser cutting apparatus according to another embodiment.

[0037] Fig. 9 is a graph showing changes in the diffraction portion of a laser cutting apparatus according to another embodiment over time.

[0038] List of reference numerals:

[0039] 100: Light source part

[0040] 200: Optical system

[0041] 210: First Optics

[0042] 230: Secondary optics

[0043] 250: Scanning unit

[0044] 270: Third Optics

[0045] 300: Optical path selection part

[0046] 400: Taiwan DETAILED DESCRIPTION

[0047] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

[0048] The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

[0049] In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

[0050] The components shown in the drawings are arbitrarily illustrated for convenience of explanation, and the present invention is not necessarily limited to the components shown.

[0051] In the drawings, the thickness is exaggerated to clearly indicate various layers and regions.

[0052] Also, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0053] When a part of a layer, film, region, or plate is referred to as being “on” or “over” another part, this includes not only the case where the part is “directly on” the other part, but also the case where the other part is present between them.

[0054] In contrast, when a portion is referred to as being “directly on top of” another portion, it means that there is no other portion between them.

[0055] Furthermore, “above” or “on” a reference portion means being located above or below the reference portion, and does not necessarily mean being located “above” or “on” the reference portion in a direction opposite to gravity.

[0056] Throughout the specification, when it is said that a part “includes” a certain element, this means that the part may further include other elements, rather than excluding other elements, unless there is a special statement to the contrary.

[0057] Throughout the specification, when we say "on a plane", this means when the target portion is viewed from above, and when we say "on a cross section", this means when we view a cross section vertically cut from the target portion from the side.

[0058] Throughout the specification, when "connected" is used, this means not only when two or more components are directly connected, but also when two or more components are indirectly connected through other components or when two or more components are physically connected. Furthermore, in the case of electrical connection, it can include each part that is called differently according to position or function but is substantially integrated.

[0059] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer and / or part from another element, component, region, layer and / or part. Therefore, without departing from the teachings herein, the "first element", "first component", "first region", "first layer" or "first part" discussed below may be referred to as the second element, second component, second region, second layer and / or second part.

[0060] The terms used herein are only used for the purpose of describing a particular embodiment, and are not intended to be limited. As used herein, unless the context clearly indicates otherwise, "a", "an", "the" and "at least one" do not represent the limitation of quantity, and are intended to include both the singular and the plural, for example, unless the context clearly indicates otherwise, "element" has the same meaning as "at least one element". "At least one" should not be interpreted as limiting "a" or "an". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items. It will also be understood that the term "comprising" and / or "comprising" or "comprising" and / or "comprising" when used in this specification specifies the existence of stated features, regions, entireties, steps, operations, elements and / or parts, but does not exclude the existence or addition of one or more other features, regions, entireties, steps, operations, elements, parts and / or their groups.

[0061] In the following, reference will be made to Figures 1 to 4 A laser cutting apparatus according to an embodiment is described.

[0062] Figure 1 is a view showing a laser cutting apparatus according to an embodiment, Figure 2 It is shown in Figure 1 A view of a curved portion of a workpiece being cut in a laser cutting device, and Figure 3 It is shown Figure 1 A view of a laser cutting apparatus, which is a view showing a second straight line processing portion of cutting a workpiece in the apparatus, and Figure 4 It is shown in Figure 1 Figure 1. Diagram of a diffractive section in a laser cutting device.

[0063] First, when explaining Figures 1 to 3 When θ1, θ2, and θ3 are shown in , θ1, θ2, and θ3 mean angles for expressing relative directivities of a diffraction pattern of each diffraction portion, and should not be understood as angles expressed as numerical values.

[0064] refer to Figures 1 to 4 , the laser cutting apparatus according to the embodiment includes a light source part 100 , an optical system 200 , a light path selection part 300 , and a stage 400 .

[0065] The light source part 100 may generate and emit input light LA1.

[0066] The input light LA1 is a laser beam and may include a gas laser such as a carbon dioxide laser, an excimer laser, a helium-neon laser, or a solid laser such as a ruby ​​laser, a glass laser, a YAG laser, a YLF laser, or the like, but is not limited thereto.

[0067] The input light LA1 may be a Gaussian laser beam in which the intensity of the beam is concentrated at the center and the vibration direction is not specified.

[0068] That is, the input light LA1 may be a laser beam vibrating in all directions perpendicular to the propagation direction of the laser beam. In other words, the input light LA1 is non-polarized light.

[0069] Optical system 200 may be located in the path of the laser beam.

[0070] Input light LA1 passing through the optical system 200 may be converted into output light LA2.

[0071] The output light LA2 may be polarized light whose vibration direction may be specified.

[0072] The optical system 200 is disposed between the light source part 100 and the stage 400 on an optical path, and can irradiate the output light LA2 in a direction toward the stage 400 .

[0073] The optical system 200 may include an optical device and a scanning unit 250 .

[0074] The optical device may include a first optical device 210 and a second optical device 230 .

[0075] The first optical device 210 may convert input light LA1 into output light LA2.

[0076] The first optics 210 may be a diffractive optical element ("DOE").

[0077] The first optical device 210 may include a diffraction portion DP1 that converts the input light LA1 into the output light LA2.

[0078] That is, the input light LA1 whose vibration direction is not specified may be converted into the output light LA2 having a specific vibration direction while passing through the diffraction portion DP1 of the first optical device 210 .

[0079] The diffraction portion DP1 of the first optical device 210 may have a diffraction pattern in a specific direction, and the vibration direction of the output light LA2 may vary according to the diffraction pattern of the diffraction portion DP1.

[0080] The diffraction portion DP1 of the first optical device 210 may be in a stationary state while the laser beam is incident.

[0081] Therefore, input light LA1 enters the first optical device 210 and is converted into polarized light by the diffraction portion DP1, and then polarized output light LA2 is emitted from (ie, passes through) the first optical device 210. Therefore, the vibration direction of the output light LA2 may be kept constant.

[0082] The vibration direction of the output light LA2 emitted from the first optical device 210 may be parallel to the cutting direction of the linear processing portion (point P1 to point P3 ) of the workpiece 10 .

[0083] That is, when the workpiece 10 is cut on a straight line from point P1 to point P3 , a vibration direction of the output light LA2 emitted from the first optical device 210 may be parallel to the straight line connecting point P1 to point P3 .

[0084] When the laser beam (ie, input light LA1) incident on the first optical device 210 starts to be incident on the second optical device 230, the diffraction portion DP1 of the first optical device 210 in a stationary state may rotate.

[0085] When the diffraction portion DP1 rotates, the diffraction pattern of the diffraction portion DP1 also rotates, and the direction of the diffraction pattern may change.

[0086] As an example, refer to Figure 2 and Figure 4 , the diffraction portion DP1 of the first optical device 210 can maintain the same as the laser beam passing through the first optical device 210. Figure 4 The diffraction pattern shown in (a) of FIG. 2 is shown in FIG. 2 , and after the laser beam (i.e., the input light LA1) passes through the first optical device 210, during the rest period until the laser beam (i.e., the input light LA1) is incident again, the diffraction portion DP1 of the first optical device 210 may be rotated by 90° to become Figure 4 The state shown in (c).

[0087] exist Figures 1 to 4 , the diffraction portion DP1 of the first optical device 210 is shown to be rotated 90° while the laser beam (i.e., input light LA1) is incident on the second optical device 230, however, the present disclosure is not limited thereto, and the angle of rotation of the diffraction portion DP1 of the first optical device 210 can be set in various ways according to the cutting shape of the workpiece 10.

[0088] The second optical device 230 may convert the input light LA1 into the output light LA2.

[0089] The second optical device 230 may be a diffractive optical device.

[0090] The second optical device 230 may include a diffraction portion DP2 that converts the input light LA1 into the output light LA2.

[0091] That is, the input light LA1 whose vibration direction is not specified may be converted into the output light LA2 (ie, polarized light) having a specific vibration direction while passing through the diffraction portion DP2 of the second optical device 230 .

[0092] The diffraction portion DP2 of the second optical device 230 may have a diffraction pattern in a specific direction, and the vibration direction of the output light LA2 may vary according to the diffraction pattern of the diffraction portion DP2.

[0093] The diffraction portion DP2 of the second optical device 230 may have the same shape as the diffraction portion DP1 of the first optical device 210, and a direction of a diffraction pattern of the diffraction portion DP2 may be different from that of the diffraction pattern of the diffraction portion DP1.

[0094] As an example, refer to Figure 1 , the diffractive portion DP2 of the second optical device 230 may be tilted by an angle θ2-θ1 compared to (ie, relative to) the diffractive portion DP1 of the first optical device 210 in an initial state before the cutting process starts.

[0095] In an embodiment, the diffraction portion DP2 of the second optical device 230 may rotate while the laser beam enters the second optical device 230 .

[0096] When the diffraction portion DP2 rotates, the diffraction pattern of the diffraction portion DP2 also rotates, and the direction of the diffraction pattern may change.

[0097] Therefore, the vibration direction of the laser beam (ie, the output light LA2 ) converted into polarized light by the diffraction portion DP2 of the second optical device 230 may be rotated along the machining direction of the curved machining portion of the workpiece 10 .

[0098] That is, when the curved processing portion (point P3 to point P4) of the workpiece 10 is cut, the output light LA2 emitted from the second optical device 230 corresponds to the cutting curve of the workpiece 10, and thus the vibration direction (ie, polarization direction) may be rotated.

[0099] The tangent of the curved processing portion to be cut of the workpiece 10 (point P3 to point P4) continuously changes along the curved cutting path, and the vibration direction of the output light LA2 emitted from the diffraction portion DP2 of the second optical device 230 (i.e., passing through the diffraction portion DP2 of the second optical device 230) can correspond to the tangent of the curved path.

[0100] For example, if the direction of the diffraction part DP2 of the second optical device 230 rotates counterclockwise, the vibration direction (ie, polarization direction) of the output light LA2 may also rotate counterclockwise.

[0101] In an initial state before the cutting process starts, the diffractive portion DP2 of the second optical device 230 may be tilted in a direction opposite to the rotation direction compared to the diffractive portion DP1 of the first optical device 210 .

[0102] As an example, refer to Figure 1 and Figure 4 In the initial state, the diffractive part DP2 of the second optical device 230 is tilted clockwise by an angle θ2-θ1 compared to the diffractive part DP1 of the first optical device 210.

[0103] However, this is an example of a case where the diffractive portion DP2 of the second optical device 230 rotates counterclockwise during the cutting process, and is not limited thereto.

[0104] When the diffractive portion DP2 of the second optical device 230 rotates clockwise during the cutting process, the diffractive portion DP2 of the second optical device 230 may be tilted counterclockwise by an angle θ2-θ1 with respect to the diffractive portion DP1 of the first optical device 210 in an initial state.

[0105] The scanning unit 250 may irradiate the output light LA2 emitted from the first optical device 210 or the second optical device 230 and incident on the scanning unit 250 to the stage 400 .

[0106] A shape to be cut for the workpiece 10 may be set in advance, and the scanning unit 250 may irradiate the laser beam while moving a propagation direction of the laser beam along the shape set for the workpiece 10 .

[0107] That is, the laser beam irradiated by the scanning unit 250 moves along a preset shape of the workpiece 10 and may cut the workpiece 10 .

[0108] The scanning unit 250 may interact with the first optical device 210 to irradiate the output light LA2 having a certain vibration direction along the straight line processing portion (point P1 to point P3) of the workpiece 10.

[0109] In addition, the scanning unit 250 may interact with the second optical device 230 to irradiate the output light LA2 whose vibration direction rotates along the curved processing portion (point P3 to point P4) of the workpiece 10.

[0110] Although not shown, the scanning unit 250 may include an optical path changing member such as a galvanometer.

[0111] The light path selection part 300 may be disposed on the light path between the light source part 100 and the optical system 200 .

[0112] The light path selection part 300 changes the light path so that the input light LA1 emitted from the light source part 100 and incident on the light path selection part 300 is guided to the first optical device 210 or the second optical device 230 .

[0113] The optical path selecting portion 300 may include a galvanometer mirror or an acousto-optic deflector ("AOD").

[0114] The stage 400 may support the workpiece 10 .

[0115] The stage 400 may provide a flat surface on which the workpiece 10 may be placed.

[0116] Although not shown, a separate component capable of moving the stage 400 may be placed under or on the side of the stage 400 .

[0117] In the following, reference will be made to Figure 5 and Figure 6 as well as Figures 1 to 4 A method of performing laser cutting using the laser cutting apparatus according to the embodiment is described.

[0118] Figure 5 is a flow chart illustrating a laser cutting method according to one embodiment.

[0119] refer to Figure 5 First, the workpiece 10 is prepared on the stage 400 ( S10 ).

[0120] Specifically, the workpiece 10 to be laser cut is placed on the upper surface of the stage 400 .

[0121] Next, a laser beam is generated and emitted from the light source part 100 .

[0122] The light source part 100 may emit a Gaussian-shaped laser beam whose vibration direction is not specified.

[0123] The laser beam incident on the optical path selection portion 300 may proceed to the first optical device 210 .

[0124] At this time, the optical path selection part 300 may adjust the direction in which the incident laser beam travels so that the laser beam travels toward the first optical device 210 ( S20 ).

[0125] In this embodiment, the case where the straight cut portion of the workpiece 10 is processed first is exemplary, but the present invention is not limited to this, and in the case where the curved cut portion of the workpiece 10 is processed first, the optical path selection portion 300 can change the path of the incident laser beam so that the path of the incident laser beam first goes to the second optical device 230.

[0126] The laser beam travelling to the first optical device 210 may change its shape after passing through the diffraction portion DP1 of the first optical device 210 .

[0127] That is, when the input light LA1 in the Gaussian form whose vibration direction is not specified passes through the diffraction part DP1 of the first optical device 210, the input light LA1 can be converted into output light LA2 having a vibration direction, and at this time, the vibration direction of the output light LA2 can be parallel to the straight line processing part (point P1 to point P3) of the workpiece 10.

[0128] The laser beam emitted from the first optical device 210 (ie, passing through the first optical device 210 ) is incident on the scanning unit 250 , and the scanning unit 250 may irradiate the incident laser beam along a preset path.

[0129] The laser beam emitted from the first optical device 210 is irradiated to the straight line processing portion (point P1 to point P3) on the workpiece 10 by the scanning unit 250 to cut the workpiece 10 on the straight line (S30).

[0130] Since the vibration direction of the laser beam emitted from the first optical device 210 is parallel to the cutting path of the straight processing portion (point P1 to point P3), the straight processing portion of the workpiece 10 can be smoothly cut without any meandering portion.

[0131] While the laser beam is incident on the first optical device 210, the diffraction portion DP2 of the second optical device 230 may start rotating (S32).

[0132] That is, while the cutting process for the straight line processing portion (point P1 to point P3) of the workpiece 10 is being performed, when the laser beam is irradiated to the point P2 on the workpiece 10, the diffractive part DP2 of the second optical device 230 may start to rotate.

[0133] Therefore, the diffraction pattern of the diffraction part DP2 of the second optical device 230 may also rotate.

[0134] Next, the optical path selection portion 300 may change the path of the incident laser beam so as to cut the curved processing portion (point P3 to point P4 ) of the workpiece 10 .

[0135] The path of the laser beam having passed through the optical path selecting portion 300 may be changed to proceed toward the second optical device 230 .

[0136] For example, the optical path selecting portion 300 may be a device that adjusts the optical path by rotating a reflecting mirror such as a galvanometer mirror.

[0137] The optical path selection part 300 performs an operation such as rotation to change the path of the laser beam. At this time, the optical path selection part 300 is operated to make the scanning unit 250 move the path of the laser beam. The speed at which the optical path selection part 300 moves the path of the laser beam is equal to or faster than the speed at which the scanning unit 250 moves the path of the laser beam.

[0138] Therefore, when the propagation direction of the laser beam is changed from the straight processing part (point P1 to point P3) to the curved processing part (point P3 to point P4) of the workpiece 10, the optical path selection part 300 selects the traveling path of the laser beam. Even when the traveling path of the laser beam is changed from the first optical device 210 to the second optical device 230, interruption of processing can be prevented.

[0139] The laser beam advancing to the second optical device 230 may be changed into polarized light after passing through the diffraction portion DP2 of the second optical device 230 .

[0140] That is, when the input light LA1 whose vibration direction is not specified passes through the diffraction portion DP2 of the second optical device 230, the input light LA1 may become the output light LA2 having a specific vibration direction (ie, polarization direction).

[0141] The diffractive portion DP2 of the second optical device 230 may rotate.

[0142] exist Figure 2 and Figure 4 , the diffractive portion DP2 of the second optical device 230 is shown to rotate counterclockwise, but the present invention is not limited thereto.

[0143] The laser beam may enter the diffraction portion DP2 while the diffraction portion DP2 is rotating.

[0144] At this time, the vibration direction of the laser beam incident on the diffraction portion DP2 is specified, and when the diffraction portion DP2 rotates, the vibration direction can also be rotated.

[0145] That is, when the diffraction portion DP2 rotates counterclockwise, the vibration direction of the laser beam may also rotate counterclockwise.

[0146] Each vibration direction of the rotating laser beam may correspond to each tangent line of the curved line processing portion (point P3 to point P4 ) of the workpiece 10 .

[0147] Figure 6 is a graph showing directions of a diffraction pattern of a diffraction part according to process time.

[0148] Figure 6 θ1, θ2, θ3, and θ4 shown in θ represent the degree of relative rotation of the diffraction pattern of the diffraction part, and do not mean absolute angles.

[0149] That is, θ1, θ2, θ3, and θ4 should be understood to mean relative rotation angles.

[0150] For example, θ1 may mean a clockwise rotation relative to θ2, and θ3 and θ4 may mean a counterclockwise rotation relative to θ2.

[0151] In addition, Figure 6 In FIG. 1 , T1 , T2 , T3 , and T4 may refer to times when the laser beam irradiates points P1 , P2 , P3 , and P4 on the workpiece 10 , respectively.

[0152] refer to Figure 6 , the diffraction part DP2 of the second optical device 230 may remain stationary and not rotate in its initial state before the laser beam (ie, the input light LA1) is emitted from the light source part 100.

[0153] Thereafter, the diffraction portion DP2 of the second optical device 230 rotates, and the laser beam may enter the diffraction portion DP2 later than when the diffraction portion DP2 starts to rotate.

[0154] In an initial state before the laser beam (ie, input light LA1) is emitted from the light source part 100, the diffraction portion DP2 of the second optical device 230 may be tilted in a direction opposite to the rotation direction compared to the diffraction portion DP1 of the first optical device 210.

[0155] refer to Figure 1 and Figure 6 , in the initial state, the diffractive portion DP2 of the second optical device 230 may be tilted clockwise by an angle θ2-θ1 compared to the diffractive portion DP1 of the first optical device 210. This is the case when the diffractive portion DP2 of the second optical device 230 rotates counterclockwise in the curved processing portion (point P3 to point P4) of the workpiece 10.

[0156] On the contrary, in the case where the diffractive portion DP2 of the second optical device 230 rotates clockwise, the diffractive portion DP2 of the second optical device 230 may be tilted counterclockwise by an angle θ2-θ1 compared to the diffractive portion DP1 of the first optical device 210 in the initial state.

[0157] The diffractive portion DP2 of the second optical device 230 may start rotating before the cutting of the straight line processing portion (point P1 to point P3) of the workpiece 10 is completed.

[0158] That is, while the laser beam passes through the first optical device 210, the diffraction portion DP2 of the second optical device 230 may start to rotate.

[0159] For example, when the laser beam passes through a point P2 on the workpiece 10, the diffractive portion DP2 of the second optical device 230 may start to rotate.

[0160] The diffraction part DP2 of the second optical device 230 starts to rotate in advance, so that when the cutting workpiece 10 transitions from the straight line processing part (point P1 to point P3) to the curve processing part (point P3 to point P4), there may be a moment when the shape of the diffraction part DP1 of the first optical device 210 and the shape of the diffraction part DP2 of the second optical device 230 are consistent.

[0161] That is, when the laser beam (i.e., the output light LA2) passes through the point P2 on the workpiece 10 (at Figure 6 At the process time T2 in the process), the diffraction portion DP2 of the second optical device 230 starts to rotate, and when the laser beam passes through the point P3 on the workpiece 10 (at Figure 6 ), the diffraction pattern of the diffraction part DP1 of the first optical device 210 and the diffraction pattern of the diffraction part DP2 of the second optical device 230 may match each other.

[0162] Therefore, without reducing the speed at which the scanning unit 250 changes the path of the laser beam (ie, the output light LA2), the cutting process can be switched from the straight processing portion to the curved processing portion at a constant speed.

[0163] The optical path selecting part 300 may change the traveling path of the laser beam to the diffraction part DP2 of the rotating second optical device 230 (S40).

[0164] The vibration direction (ie, polarization direction) of the laser beam passing through the second optical device 230 may be rotated according to the rotation of the diffraction portion DP2.

[0165] The rotation angle of the diffraction portion DP2 may correspond to the change angle of the curved processing portion of the workpiece 10 .

[0166] For example, when the tangent line of the starting point P3 and the tangent line of the end point P4 of the curved processing portion of the workpiece 10 form an angle of 90°, the diffractive portion DP2 also corresponds to the diffractive portion DP1 of the first optical device 210 in the initial state and can be rotated by 90°.

[0167] That is, when the tangent line at point P2 and the tangent line at point P3 are perpendicular to each other, the diffraction portion DP2 of the second optical device 230 can be rotated 90°, and in the laser passing through the second optical device 230, the vibration direction of the beam can also be rotated 90°.

[0168] The time taken by the optical path selection portion 300 to adjust the path of the laser beam from the first optical device 210 to the second optical device 230 or from the second optical device 230 to the first optical device 210 can be equal to or shorter than the time taken by the scanning unit 250 to move the propagation direction of the laser beam (i.e., the output light LA2).

[0169] When the laser beam (ie, input light LA1) travels toward the second optical device 230, the diffraction portion DP1 of the first optical device 210 may rotate (S42).

[0170] The rotation angle θ4-θ2 of the diffraction portion DP1 of the first optical device 210 during the time period T3 to T4 may correspond to the angle between the extension line of the first straight line processing portion (point P1 to point P3) and the extension line of the second straight line processing portion (point P4 to point P5) of the workpiece 10.

[0171] As an example, refer to Figure 3 and Figure 6 When the angle between the extension line of the first straight line processing portion (point P1 to point P3) and the extension line of the second straight line processing portion (point P4 to point P5) of the workpiece 10 is 90°, the diffraction portion DP1 of the first optical device 210 can also be rotated 90°.

[0172] When the diffractive portion DP1 of the first optical device 210 rotates, the first optical device 210 may be ready to cut the second straight line processing portion (point P4 to point P5).

[0173] The laser beam emitted from the second optical device 230 (ie, output light LA2) proceeds to the scanning unit 250, and the scanning unit 250 may irradiate the incident laser beam along a preset path.

[0174] The laser beam emitted from the second optical device 230 (ie, passing through the second optical device 230 ) is irradiated to the curved line processing portion (point P3 to point P4 ) on the workpiece 10 by the scanning unit 250 to cut the workpiece 10 into a curved line ( S50 ).

[0175] Since the changed vibration direction (i.e., polarization direction) of the laser beam emitted from the second optical device 230 corresponds to the tangent of the path used to cut the curved processing portion (point P3 to point P4) of the workpiece 10 into a curve, the workpiece 10 can be cut smoothly along the curved processing portion (point P3 to point P4).

[0176] At the point ( Figure 6 At a point P4 at a process time T4 of 1,000, the optical path selecting portion 300 may change the optical path so that the laser beam is directed toward the first optical device 210 (S60).

[0177] The optical path selecting part 300 performs an operation of changing the path of the laser beam, and at this time, the operation of the optical path selecting part 300 is equal to or faster than the moving speed of the path changing member of the scanning unit 250 .

[0178] Since the diffraction portion DP1 of the first optical device 210 is rotated to correspond to the second straight line processing portion (point P4 to point P5) of the workpiece 10, the cutting of the second straight line processing portion (point P4 to point P5) can be performed by changing the travel path of the laser beam.

[0179] When the traveling path of the laser beam is changed to be directed to the first optical device 210 , the diffractive portion DP2 of the second optical device 230 may be rotated to prepare for cutting another curved processing portion of the workpiece 10 .

[0180] As described above, when cutting of the straight processing portion is being performed, the diffractive portion DP2 of the second optical device 230 may be tilted clockwise compared to the diffractive portion DP1 of the first optical device 210 .

[0181] That is, when cutting the straight processing portion, the diffractive portion DP2 of the second optical device 230 may be inclined clockwise by an angle θ4-θ3 with respect to the diffractive portion DP1 of the first optical device 210.

[0182] This is the case when the diffractive portion DP2 rotates counterclockwise. In the case where the diffractive portion DP2 rotates clockwise, the diffractive portion DP2 of the second optical device 230 may be tilted counterclockwise compared to (ie, relative to) the diffractive portion DP1.

[0183] Immediately after the travel path of the laser beam is changed to be directed to the first optical device 210, the diffraction part DP2 of the second optical device 230 gradually reduces its rotation speed to a stop state, and then rotates again in the opposite direction as above, so that the diffraction part DP2 of the second optical device 230 can be tilted relative to the diffraction part DP1 of the first optical device 210.

[0184] Figure 7 is a graph comparing laser cutting using a single optical device and laser cutting using multiple optical devices according to the present embodiment.

[0185] Figure 7 (A) shows a graph of cutting a workpiece 10 using a laser cutting apparatus in which only one optical device is provided.

[0186] The diffraction portion DP0 is in a stationary state during a period from T1 to T3 , and during this period, the laser beam passing through the optical device cuts the straight-line processing portion (point P1 to point P3 ) of the workpiece 10 .

[0187] When reaching the time point T3, the diffractive part DP0 of the optical device starts to rotate to cut the curved processing part.

[0188] At this time, the diffraction part DP0 in the stopped state needs to reduce the speed of the scanning unit that changes the movement path of the laser beam (scanning speed, speed of the scanning unit) so as to correspond to the delay time until the speed of the scanning unit reaches a certain rotation speed (a speed corresponding to the speed at which the scanning unit changes the movement path of the laser beam).

[0189] Furthermore, while cutting the curved line processing portion (point P3 to point P4) of the workpiece 10, the rotation speed of the diffractive portion DP0 of the optical device must be reduced.

[0190] Therefore, the speed of the scanning unit must be reduced in response to the deceleration of the diffractive part DP0.

[0191] Figure 7 (B) is a graph showing the cutting of the workpiece 10 using the laser cutting apparatus of the present embodiment.

[0192] The laser beam passing through the diffraction portion DP1 of the first optical device 210 cuts a straight line processing portion of the workpiece 10 during the time period (T1 to T3).

[0193] At time T2, the diffraction portion DP2 of the second optical device 230 starts to rotate, and when it reaches time T3, the rotation speed of the diffraction portion DP2 is set to a constant rotation speed (depending on the speed at which the scanning unit changes the moving path of the laser beam) (corresponding speed), thereby being able to transition from cutting in the straight processing portion to cutting in the curved processing portion without slowing down the speed of the scanning unit.

[0194] In addition, the diffractive portion DP1 of the first optical device 210 at the angle of θ2 is rotated to θ4 during the time period (T3 to T4).

[0195] Therefore, when transitioning from cutting the curved processing portion to cutting the straight processing portion of the workpiece 10 at time T4, the speed of the scanning unit can be maintained, and thus the process time can be shortened by the (T4'-T4) time.

[0196] In the following, reference will be made to Figure 8 and Fig. 9 as well as Figures 1 to 4 A laser cutting apparatus according to another embodiment is described.

[0197] Figure 8 is a diagram showing a laser cutting apparatus according to another embodiment, and Fig. 9is a graph showing changes in the diffraction portion of a laser cutting apparatus according to another embodiment over time.

[0198] The laser cutting device according to this embodiment is different from the reference Figures 1 to 4 The described implementations are similar.

[0199] Detailed description of the same components is omitted.

[0200] refer to Figure 8 According to the present embodiment, the laser cutting device may further include a third optical device 270 in the optical system 200 .

[0201] The third optical device 270 may convert the input light LA1 into the output light LA2.

[0202] The third optical device 270 may be a diffractive optical device.

[0203] The third optical device 270 may include a diffraction portion DP3 that converts the input light LA1 into the output light LA2.

[0204] That is, the input light LA1 whose vibration direction is not specified may be converted into the output light LA2 having a vibration direction (ie, polarization direction) after passing through the diffraction portion DP3 of the third optical device 270 .

[0205] The diffraction portion DP3 of the third optical device 270 may have a diffraction pattern having a specific direction.

[0206] The diffraction portions DP3 of the third optical device 270 may have the same shape, and only the directions of the diffraction patterns may be different.

[0207] The diffraction portion DP3 of the third optical device 270 may have a diffraction pattern in a direction different from that of the diffraction portion DP1 of the first optical device 210 in an initial state before the cutting process starts.

[0208] The angle formed by the diffraction pattern of the diffraction portion DP1 of the first optical device 210 and the diffraction pattern of the diffraction portion DP3 of the third optical device 270 may correspond to the angle formed by the extension of the first linear processing portion and the extension line of the second linear processing portion on the workpiece 10 .

[0209] That is to say, reference Fig. 9 , the diffraction pattern of the diffraction part DP3 of the third optical device 270 and the diffraction pattern of the diffraction part DP1 of the first optical device 210 may form an angle θ4-θ2 in an initial state before the cutting process starts.

[0210] For example, when the angle formed by the extension line of the first straight line processing portion and the extension line of the second straight line processing portion on the workpiece 10 is 90°, the diffraction pattern of the diffraction portion DP3 of the third optical device 270 and the first diffraction pattern of the diffraction portion DP1 of the first optical device 210 can form an angle of 90°.

[0211] In the following, reference will be made to Figure 8 and Fig. 9 A method of cutting a workpiece using a laser cutting apparatus according to another embodiment is described.

[0212] The laser cutting method according to this embodiment is similar to the reference Figure 5 and Figure 6 The laser cutting method described is similar.

[0213] Detailed description of the same process is omitted.

[0214] After the first straight line processing portion (point P1 to point P3) of cutting the workpiece 10 is completed, the diffractive portion DP1 of the first optical device 210 is rotated.

[0215] At this time, the diffraction portion DP1 of the first optical device 210 may be rotated to have a diffraction pattern corresponding to the third straight line processing portion (point P6 to point P7 ) of the workpiece 10 .

[0216] For example, when the first straight line processing portion (point P1 to point P3) and the third straight line processing portion (point P6 to point P7) are parallel, the diffractive portion DP1 of the first optical device 210 may not rotate.

[0217] When the cutting of the first curved processing portion (point P3 to point P4 ) of the workpiece 10 is completed, the optical path selection portion 300 may adjust the propagation direction of the laser beam so that the laser beam faces the third optical device 270 .

[0218] The laser beam having passed through the third optical device 270 may be irradiated by the scanning unit 250 along the second straight line processing portion (point P4 to point P5 ) of the workpiece 10 to cut the workpiece 10 .

[0219] According to the laser cutting method using the laser cutting apparatus according to the present embodiment, even when the travel path movement speed of the laser beam of the scanning unit 250 is too fast, the workpiece 10 can be processed without deceleration.

[0220] That is, when the diffractive portion DP1 of the first optical device 210 is rotated at a small angle such as 90° or less, before the cutting of the curved processing portion is completed, the first optical device 210 may not be rotated to correspond to the second straight processing portion (point P4 to point P5) due to the limitation of acceleration. According to this embodiment, if the rotation of the diffractive portion DP1 cannot be completed, the fast speed of the scanning unit 250 can be responded to by passing the laser beam through the third optical device 270.

[0221] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements may be made by those skilled in the art using the basic concept of the present invention defined in the appended claims.

Claims

1. Laser cutting equipment, characterized in that, include: A light source portion configured to emit a laser beam; Table, for placing workpieces; an optical system including a scanning unit configured to irradiate the laser beam to the stage and change an irradiation direction of the laser beam along a set shape of the workpiece, and an optical device disposed on a path of the laser beam from the light source portion to the scanning unit; as well as An optical path selecting section is provided between the light source section and the optical system and is configured to adjust the path of the laser beam so that the laser beam moves to one of the optical devices.

2. The laser cutting equipment according to claim 1, characterized in that: The optical device includes a first optical device and a second optical device, each of the first optical device and the second optical device having a diffraction portion configured to convert an incident laser beam into polarized light, and The diffraction portion has a diffraction pattern that selects a vibration direction of the polarized light.

3. The laser cutting equipment according to claim 2, characterized in that: The diffraction pattern of the diffraction portion of the first optical device and the diffraction pattern of the diffraction portion of the second optical device are different from each other in a stationary state.

4. The laser cutting equipment according to claim 3, characterized in that: Compared to the diffraction pattern of the diffraction part of the first optical device, the diffraction pattern of the diffraction part of the second optical device is inclined in the stationary state in a direction opposite to a direction in which the diffraction part of the second optical device is rotated.

5. The laser cutting equipment according to claim 2, characterized in that: A rotation time of the diffractive portion of the first optical device and a rotation time of the diffractive portion of the second optical device do not at least partially overlap.

6. The laser cutting equipment according to claim 2, characterized in that: The set shape of the workpiece has a straight processing portion and a curved processing portion, and The optical path selecting portion adjusts the path of the laser beam to be directed to the first optical device during cutting of the straight processing portion, and adjusts the path of the laser beam to be directed to the second optical device during cutting of the curved processing portion.

7. The laser cutting equipment according to claim 2, characterized in that: When the laser beam is incident on the first optical device, the diffractive portion of the first optical device is in a stationary state, and When the laser beam is incident on the second optical device, the diffractive portion of the second optical device is in a rotating state.

8. The laser cutting device according to claim 1, characterized in that: The scanning unit changes the path of the laser beam at a constant speed.

9. The laser cutting device according to claim 2, characterized in that: The optical device further includes a third optical device having a diffraction portion configured to convert an incident laser beam into polarized light, The diffraction portion has a diffraction pattern that selects a vibration direction of the polarized light, and The diffraction pattern of the diffraction portion of the first optical device, the diffraction pattern of the diffraction portion of the second optical device, and the diffraction pattern of the diffraction portion of the third optical device are different from each other in a stationary state.

10. The laser cutting device according to claim 9, characterized in that: The set shape of the workpiece has a straight processing portion and a curved processing portion, and The optical path selecting portion adjusts the path of the laser beam to be directed to the first optical device or the third optical device during cutting of the straight processing portion, and adjusts the path of the laser beam to be directed to the second optical device during cutting of the curved processing portion.

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