[0001]The present invention relates to a grooving device and a grooving method for forming a groove in an object by a laser. The present application claims priority based on Japanese Patent Application No. 2019-091044 filed in Japan on May 14, 2019, and these contents are incorporated herein by reference.
Background technology
[0002]
　For some time, a polygon mirror has been used to irradiate the surface of a steel sheet with a laser beam in a direction that intersects the sheet-passing direction of the steel sheet (scanning direction) to periodically form grooves on the surface of the steel sheet, resulting in iron loss. Grooving devices that improve characteristics are known (see, for example, Patent Document 1).
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 2002-292484
Outline of the invention
Problems to be solved by the invention
[0004]
　As shown in FIGS. 1A and 1B, the laser beam LB incident on the polygon mirror 10 of the groove processing device is not a point light source but has a predetermined radius φ.
[0005]
　As shown in FIG. 1A, when the laser beam LB is incident so as to fit on one surface of the polygon mirror 10, the laser beam LB reflected from the polygon mirror 10 is one of the surfaces of the steel plate 20 via the condenser lens 12. The light is collected at the spots, and grooves are formed at the spots on the surface of the steel plate 20.
[0006]
　On the other hand, as shown in FIG. 1B, when the laser beam LB is incident on a corner portion of the polygon mirror 10 that straddles two adjacent surfaces, the laser beam LB is reflected from each of the two adjacent surfaces. It is divided into two laser beams LB1 and LB2. The divided laser beams LB1 and LB2 are focused on the surface of the steel plate 20 via the condenser lens 12. As a result, the ends of the grooves in the scanning direction are machined with laser beams LB1 and LB2 with insufficient energy densities. Therefore, the end portion of the groove becomes shallow, and a uniform groove cannot be formed. Further, the divided laser beams LB1 and LB2 are irradiated in a direction different from that of the laser beam LB. Therefore, there is a possibility that a position different from the position where the groove on the surface of the steel sheet 20 should be formed, or another device other than the surface of the steel sheet 20 may be mistakenly processed.
[0007]
　In order to avoid such a situation, it is conceivable to provide a shielding plate such as a mask so as not to irradiate the laser beams LB1 and LB2 at the portion corresponding to the end of the groove. However, in such a configuration, the shielding plate itself is processed, and there is a problem that the optical components are contaminated.
[0008]
　The present invention has been made in view of the above problems, and an object of the present invention is to provide a grooving device and a grooving method that realize uniform grooving and grooving depth without contaminating optical components.
Means to solve problems
[0009]
　Means for solving the problem include the following aspects.
(1) The grooving device according to an embodiment of the present invention is a grooving device that forms a groove on the surface of an object by a laser beam, and is a light source device that outputs the laser beam and outputs from the light source device. A polygon mirror that reflects the laser beam and an optical system provided in the optical path of the laser beam reflected from the polygon mirror, and the laser beam reflected from one surface of the polygon mirror is passed through the polygon mirror. A light-collecting portion that collects light on the surface of the object and a laser beam that is provided outside the light-collecting unit and is reflected from a corner portion that straddles two adjacent surfaces of the polygon mirror are passed through the object. It is provided with an optical system having a non-light source portion that does not collect light on the surface of the light source.
(2) In the groove processing apparatus according to (1) above, the non-condensing portion does not have to have a focal point.
(3) In the groove processing apparatus according to (1) above, the non-condensing portion may diverge the laser beam reflected from the corner portion of the polygon mirror.
(4) In the groove processing apparatus according to any one of (1) to (3) above, a shielding plate may be provided in the optical path of the laser beam that has passed through the non-condensing portion.
(5) The grooving method according to the embodiment of the present invention is a grooving method for forming a groove on the surface of an object by a laser beam, and is an output step for outputting the laser beam by a light source device and a polygon. A reflection step that reflects the laser beam output from the light source device by the mirror, and the laser beam reflected from one surface of the polygon mirror are passed through a condensing unit and condensed on the surface of the object. The laser beam reflected from the light collecting section passing step and the corner portion straddling two adjacent surfaces of the polygon mirror is passed through a non-light collecting section provided outside the light collecting section to pass the object. It is provided with a non-condensing portion passing step that does not condense light on the surface.
(6) In the groove processing method according to (5) above, the non-condensing portion does not have to have a focus in the non-condensing portion passing step.
(7) In the groove processing method according to (5) above, the laser beam may be emitted in the non-condensing portion in the non-condensing portion passing step.
(8) In the groove processing method according to any one of (5) to (7) above, the laser beam that has passed through the non-condensing portion in the non-condensing portion passing step is passed through the optical path of the laser beam. A shielding step may be further provided for shielding by using the shielding plate provided in the above.
The invention's effect
[0010]
　According to the present invention, by allowing the laser beam reflected from the corner portion of the polygon mirror to pass through the non-condensing portion of the optical system, a groove is not formed on the surface of the object. Thereby, it is possible to provide a grooving apparatus and a grooving method that realize uniform grooving and grooving depth without contaminating the optical component.
A brief description of the drawing
[0011]
FIG. 1A is a schematic diagram showing a state in which a laser beam reflected from a polygon mirror is focused on the surface of a steel plate when the laser beam is incident so as to fit on one surface of the polygon mirror.
FIG. 1B is a schematic diagram showing a state in which a laser beam reflected from each of two adjacent surfaces is focused on the surface of a steel plate when the laser beam is incident on two adjacent surfaces of a polygon mirror. ..
FIG. 2 is a schematic view showing a configuration of a grooving apparatus according to an embodiment of the present invention as viewed from the rolling direction of a steel sheet.
[Fig. 3] Fig. 3 is a schematic diagram for explaining the rotation angle of a polygon mirror.
[Fig. 4] Fig. 4 is a schematic diagram for explaining the size of a lens.
FIG. 5A is a schematic diagram showing a rotation angle of a polygon mirror and an irradiation state of a laser beam.
FIG. 5B is a schematic diagram showing a rotation angle of a polygon mirror and an irradiation state of a laser beam.
[Fig. 5C] Fig. 5C is a schematic diagram showing the rotation angle of a polygon mirror and the irradiation state of a laser beam.
[Fig. 5D] It is a schematic diagram showing the rotation angle of a polygon mirror and the irradiation state of a laser beam.
[Fig. 5E] Fig. 5E is a schematic diagram showing the rotation angle of a polygon mirror and the irradiation state of a laser beam.
FIG. 6 is a schematic diagram showing how the spot of a laser beam on the surface of a steel plate changes according to the rotation angle of a polygon mirror.
FIG. 7 is a schematic view showing a configuration of a groove processing apparatus according to a modification 1 of the present embodiment as viewed from the rolling direction of a steel sheet.
FIG. 8 is a schematic view showing a configuration of a grooving apparatus according to Modification 2 of the present embodiment as viewed from the rolling direction of a steel sheet.
Embodiment for carrying out the invention
[0012]
　Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, the same components are designated by the same reference numerals.
[0013]
　FIG. 2 schematically shows the configuration of the groove processing apparatus 100 according to the embodiment of the present invention as viewed from the rolling direction of the steel plate 20. The grooving apparatus 100 is an apparatus for periodically forming grooves on the surface of a steel plate 20 which is an object to be machined by a laser. The steel sheet 20 is made of, for example, a well-known grain-oriented electrical steel sheet material. The grooving apparatus 100 is set, for example, in the width direction (position in) of the steel plate 20 based on the length and position of the groove formed on the surface of the steel plate 20, and the steel plate 20 is set based on the dimensions of the grooving apparatus 100. The position in the longitudinal direction of the steel plate 20 is set. The width direction of the steel plate 20 is the scanning direction, which is the left-right direction of the paper surface in FIG. 2. The longitudinal direction of the steel plate 20 is, for example, the rolling direction of the steel plate 20. , The paper depth direction in FIG. 2.
[0014]
　As shown in FIG. 2, the groove processing device 100 includes a polygon mirror 10, a light source device 11, a collimator 11A, and a lens 13.
[0015]
　The polygon mirror 10 has, for example, a regular polygonal prism, and a plurality of (N) plane mirrors are provided on each of a plurality of side surfaces constituting the regular polygonal prism. The laser beam LB is incident on the polygon mirror 10 from the light source device 11 via the collimator 11A in one direction (horizontal direction) and reflected by the plane mirror (reflection step).
[0016]
　The polygon mirror 10 can rotate around the rotation axis O1 by being driven by a motor (not shown), and the incident angle of the laser beam LB with respect to the plane mirror changes sequentially according to the rotation angle of the polygon mirror 10. As a result, the reflection direction of the laser beam LB is sequentially changed, and the laser beam LB can be scanned in the width direction of the steel plate 20.
[0017]
　Although FIGS. 1A to 1B, FIGS. 2, 3, 5, 5A to 5E, 7 and 8 show an example in which the polygon mirror 10 has eight plane mirrors, the polygon mirror 10 constitutes the polygon mirror 10. The number of plane mirrors is not particularly limited.
[0018]
　The light source device 11 outputs a laser beam by a predetermined irradiation method (for example, continuous irradiation method or pulse irradiation method) under the control of a control unit (not shown) (output step).
[0019]
　The collimator 11A is connected to the light source device 11 via an optical fiber cable 15. The collimator 11A adjusts the radius of the laser beam output from the light source device 11 and outputs the adjusted laser beam LB. The laser beam LB has a laser diameter having a predetermined radius φ, and the laser diameter is circular, but may be elliptical. In that case, the condensing shape can be made elliptical by inserting a cylindrical lens or a cylindrical mirror between the collimator 11A and the polygon mirror 10 to change the beam radius of one axis (for example, the scanning direction).
[0020]
　The lens 13 is an optical system provided in the optical path of the laser beam reflected from the polygon mirror 10, and is manufactured by subjecting a single piece of glass to processing such as grinding and polishing. The lens 13 has a condensing unit 13A and a non-condensing unit 13B integrally provided on the outside (outer circumference) of the condensing unit 13A. In the following description, the case where the lens 13 is configured by a single lens is illustrated, but the lens 13 may be configured by using a plurality of sets of lenses. A mirror may be adopted instead of the lens 13.
[0021]
　The light collecting unit 13A is located in the optical path of the laser beam LB reflected from one plane mirror of the polygon mirror 10. The condensing unit 13A constitutes a condensing optical system having a radius rc and a focal length f. The laser beam LB reflected from the polygon mirror 10 passes through the condensing portion 13A and is condensed on the surface of the steel plate 20 (condensing portion passing step), whereby a groove is formed on the surface of the steel plate 20.
[0022]
　The non-condensing unit 13B is located in the optical path of the laser beams LB1 and LB2 that are divided and reflected from the corners of the polygon mirror 10 that straddle the adjacent two-sided plane mirrors, and pass the divided laser beams LB1 and LB2. (Step through non-condensing part). The non-condensing unit 13B is a donut-shaped flat plate-shaped optical system in which the inner circle has a radius rc (= the radius of the condensing unit 13A) and the outer circle has a radius r0. The non-focusing unit 13B has no focal length because the focal length is infinite. Therefore, the laser beams LB1 and LB2 that have passed through the non-condensing portion 13B irradiate the surface of the steel plate 20, but the energy density does not increase because the laser beams LB1 and LB2 do not condense, and grooves are not formed on the surface of the steel plate 20. Further, even when the laser beams LB1 and LB2 are not irradiated on the surface of the steel plate 20, the laser beams LB1 and LB2 deviating from the steel plate 20 may erroneously process the device or the like around the steel plate 20. do not have.
[0023]
　Further, in the groove processing method of irradiating the surface of the steel sheet 20 with the laser beam LB to form a groove, the ground iron is melted and removed to form the groove. Therefore, when the groove is deepened, the probability of occurrence of molten protrusions on the surface is high. Become. Therefore, the groove processing apparatus 100 may be provided with a supply nozzle (not shown) for injecting an assist gas for blowing off the melt.
[0024]
　Next, the rotation angle of the polygon mirror 10 will be described with reference to FIG.
　In the present embodiment, the rotation angle θ (°) of the polygon mirror 10 is defined by the central angle with respect to the reference position for each of the plane mirrors constituting the polygon mirror 10. As shown in FIG. 3, the position where the perpendicular line PL is drawn from the rotation axis O1 of the polygon mirror 10 to the plane mirror 101 is set as a reference position (θ = 0 °). The rotation angle θ of the polygon mirror 10 is an angle (central angle) formed by the position of the center LBc of the laser beam LB incident on each plane mirror with respect to the reference position (θ = 0 °). In FIG. 3, the counterclockwise angle is defined as a positive angle and the clockwise angle is defined as a negative angle with respect to the reference position (θ = 0 °; perpendicular line PL).
[0025]
　The angle θ0 formed by the reference position (θ = 0 °) in each plane mirror and the boundary between the adjacent plane mirrors is 180 ° / N. The rotation angle θ in one plane mirror is defined in the range of −θ0 ≦ θ ≦ + θ0. Therefore, in FIG. 3, the rotation angle θ = + θ0 in the plane mirror 101 and the rotation angle θ = −θ0 in the plane mirror 102 adjacent to the plane mirror 101 in the counterclockwise direction indicate the same position on the polygon mirror 10.
[0026]
　In the present embodiment, the maximum angle at which the incident laser beam LB fits on one surface (one plane mirror) of the polygon mirror 10 is defined as the critical angle θc. That is, the critical angle θc is the center LBc of the laser beam LB when the laser beam LB is totally reflected by one plane mirror without being divided by the corners straddling the adjacent two plane mirrors of the polygon mirror 10. Is the maximum angle at which is located. Assuming that the radius (circumscribed radius) of the circumscribed circle C1 of the polygon mirror 10 is R and the radius of the laser beam LB incident on the polygon mirror 10 is φ, the critical angle θc is defined as in the equation (1).
[0027]
θc = sin -1 [(R × sin θ0−φ) / R]… (1)
[0028]
　The size of the lens 13 can be defined by using the rotation angle θ of the polygon mirror 10. As shown in FIG. 4, where L is the distance between the reference position (θ = 0 °) on the plane mirror 101 and the condensing unit 13A, the radius rc of the condensing unit 13A and the radius of the outer circle of the non-condensing unit 13B. r0 is given as in equations (2) and (3), respectively.
rc = L × tan2θc + φ / cos2θc… (2)
r0 = L × tan2θ0 + φ / cos2θ0… (3)
[0029]
　For example, it is assumed that the groove processing apparatus 100 is designed with the following specifications:
the radius φ of the laser beam LB: 6 mm;
the number of plane mirrors constituting the polygon mirror 10 N: 8; the
circumscribed radius R: 140 mm.
　As a result, θ0 = 22.5 ° and the critical angle θc = 19.9 °.
　Assuming that the distance L = 50 mm, rc = 49.4 mm and r0 = 58.5 mm from the equations (2) and (3).
[0030]
　Next, the relationship between the rotation angle of the polygon mirror 10 and the irradiation state of the laser beam LB will be described with reference to FIGS. 5A to 5E and FIG.
[0031]
　5A-5E show the irradiation state of the laser beam LB when the polygon mirror 10 is rotated clockwise from the rotation angle θ = 0 ° of the plane mirror 101 to the rotation angle θ = 0 ° of the adjacent plane mirror 102.
[0032]
　When the rotation angle θ of the plane mirror 101 is at the position −θc ≦ θ ≦ + θc, the laser beam LB incident on the plane mirror 101 is reflected downward from the plane mirror 101 (direction toward the surface of the steel plate 20), and the condensing portion 13A. Condenses on the surface of the steel plate 20. In particular, when the rotation angle θ = 0 °, as shown in FIG. 5A, the laser beam LB incident on the plane mirror 101 is in the vertical direction (direction perpendicular to the surface of the steel plate 20) from the plane mirror 101. It is reflected, passes through the center of the light collecting portion 13A, and collects light on the surface of the steel plate 20. Therefore, when the rotation angle θ of the plane mirror 101 is at the position of −θc ≦ θ ≦ + θc, the laser beam LB is kept focused on the surface of the steel plate 20 as the polygon mirror 10 rotates. The position where the laser beam LB is reflected will change. As a result, a groove is formed on the surface of the steel sheet 20 in the width direction (scanning direction).
[0033]
　When the plane mirror 101 reaches the position of the rotation angle θ = + θc, as shown in FIG. 5B, the laser beam LB reflected from the plane mirror 101 passes through the first end portion 131 of the condensing portion 13A and reaches the surface of the steel plate 20. Condensate.
[0034]
　As shown in FIG. 5C, when the plane mirror 101 exceeds the position of the rotation angle θ = + θ0, and when the plane mirror 102 is in the position before the rotation angle θ = −θ0 (that is, the laser beam LB is adjacent). (When incident on a corner portion straddling the two-sided plane mirrors 101 and 102), the incident laser beam LB is reflected by the two plane mirrors 101 and 102, respectively, and is divided into two laser beams LB1 and LB2. .. The two laser beams LB1 and LB2 pass through the non-condensing portion 13B and irradiate the surface of the steel plate 20 and the devices around it.
[0035]
　When the plane mirror 102 reaches the position of the rotation angle θ = -θc, as shown in FIG. 5D, the laser beam LB reflected from the plane mirror 102 is on the opposite side of the first end portion 131 of the condensing portion 13A. It passes through the two ends 132 and collects light on the surface of the steel plate 20.
[0036]
　When the rotation angle of the plane mirror 102 becomes the position of −θc ≦ θ ≦ + θc, the laser beam LB incident on the plane mirror 102 is reflected downward from the plane mirror 102 (direction toward the surface of the steel plate 20), and the light collecting portion 13A is moved. As it passes, it collects light on the surface of the steel plate 20. In particular, when the plane mirror 102 reaches the position of the rotation angle θ = 0 °, as shown in FIG. 5E, the laser beam LB incident on the plane mirror 102 is reflected vertically from the plane mirror 102 and is the center of the condensing portion 13A. Condenses on the surface of the steel plate 20.
[0037]
　Focusing on one plane mirror 101, when the range of the rotation angle θ is −θc ≦ θ ≦ + θc, the laser beam LB reflected from the plane mirror 101 passes through the light collecting portion 13A and is focused on the surface of the steel plate 20. do. On the other hand, when the range of the rotation angle θ is -θ0≤θ <-θc or + θc <θ≤ + θ0, the laser beams LB1 and LB2 reflected from the corners straddling the plane mirror 101 and the adjacent plane mirror are not focused. The surface of the steel plate 20 is irradiated through the portion 13B, but the light is not collected and the energy density does not increase.
[0038]
　FIG. 6 shows when the polygon mirror 10 rotates clockwise from the position of the plane mirror 101 at the rotation angle θ = 0 ° to the position of the adjacent plane mirror 102 at the rotation angle θ = 0 ° (see FIGS. 5A to 5E). , Represents a change in the spot of the laser beam on the surface of the steel plate 20. The dotted line shown in FIG. 6 represents the scanning direction of the laser beam.
[0039]
　As shown in FIG. 6, when the range of the rotation angle θ of the plane mirror 101 is 0 ≦ θ ≦ + θc (see FIGS. 5A and 5B), the laser beam LB reflected from the plane mirror 101 is minute on the surface of the steel plate 20. The light is collected by the circular spot S1. As the rotation angle θ increases, the spot S1 moves in one direction (left side in FIG. 6).
[0040]
　When the range of the rotation angle θ of the plane mirror 101 is + θc <θ ≦ + θ 0, and when the range of the rotation angle θ of the plane mirror 102 is −θ0 ≦ θ <−θc, the laser beam LB is 2 as described above. It is divided into two laser beams LB1 and LB2. The two laser beams LB1 and LB2 irradiate the surface of the steel sheet 20 via the non-condensing portion 13B to form two spots S2 and S3 corresponding to each. Since the laser beams LB1 and LB2 are not focused on the surface of the steel plate 20, each of the spots S2 and S3 has a larger area than the spot S1.
[0041]
　When the range of the rotation angle θ of the plane mirror 101 is + θc <θ <+ θ0, the amount of light of the laser beam LB1 reflected from the plane mirror 101 is larger than the amount of light of the laser beam LB2 reflected from the plane mirror 102, so that the spot S2 Has a larger area than the spot S3.
[0042]
　When the plane mirror 101 is at the position of the rotation angle θ = + θ0 and when the plane mirror 102 is at the position of the rotation angle θ = −θ0 (see FIG. 5C), the amount of light of the laser beam LB1 and the amount of light of the laser beam LB2 are equal. Therefore, the area of ​​the spot S2 and the area of ​​the spot S3 are the same.
[0043]
　When the range of the rotation angle θ of the plane mirror 102 is −θ0 <θ <−θc, the amount of light of the laser beam LB2 reflected from the plane mirror 102 is larger than the amount of light of the laser beam LB1 reflected from the plane mirror 101, so that the spot S3 has a larger area than spot S2.
[0044]
　When the range of the rotation angle θ of the plane mirror 102 is −θc ≦ θ ≦ 0 (see FIGS. 5D and 5E), the laser beam LB reflected from the plane mirror 102 is formed by a minute circular spot S1 on the surface of the steel plate 20. It is focused. As the rotation angle θ approaches 0 °, the spot S1 moves in one direction (left side in FIG. 6).
[0045]
　As described above, according to the present embodiment, when the laser beam LB is divided and reflected from the corner portion of the polygon mirror 10 that straddles two adjacent surfaces, the divided laser beams LB1 and LB2 form the non-condensing portion 13B. By passing through, the light is not focused on the surface of the steel plate 20, and the energy density is not increased, so that a groove is not formed on the surface of the steel plate 20. As a result, unlike the conventional case, the end of the groove in the scanning direction does not become shallow, uniform groove processing and groove depth can be realized, and a product having excellent iron loss characteristics can be produced. Can be done. Further, the device or the like around the steel plate 20 is not mistakenly processed.
[0046]
　In the above-described embodiment of FIGS. 2 to 6, the non-condensing portion 13B of the lens 13 is a planar optical system having no focal point, but an optical system that diverges the divided laser beams LB1 and LB2 (FIG. 2). 7) may be adopted.
[0047]
　FIG. 7 shows a configuration of the grooving apparatus 200 as a modification 1 of the present embodiment as viewed from the rolling direction of the steel plate 20. The grooving apparatus 200 includes a lens 17 in place of the lens 13 of the grooving apparatus 100 shown in FIGS. 2 and 5A to 5E.
[0048]
　The lens 17 is an optical system provided in the optical path of the laser beam reflected from the polygon mirror 10, and is manufactured by subjecting a single piece of glass to processing such as grinding and polishing. The lens 17 has a condensing unit 17A and a non-condensing unit 17B integrally provided on the outside (outer circumference) of the condensing unit 17A.
[0049]
　Similar to the light collecting unit 13A of the lens 13, the light collecting unit 17A is located in the optical path of the laser beam LB reflected from one plane mirror of the polygon mirror 10 and constitutes a light collecting optical system having a focal length f.
[0050]
　The non-condensing unit 17B is located in the optical path of the laser beams LB1 and LB2 divided and reflected from the corners of the polygon mirror 10, and passes through the divided laser beams LB1 and LB2. The non-condensing portion 17B is thick toward the peripheral portion, the surface on the polygon mirror 10 side is a concave spherical surface toward the polygon mirror 10, and the surface on the steel plate 20 side is a flat surface. The surface of the non-condensing portion 17B on the steel plate 20 side may also be a spherical surface concave toward the steel plate 20. The boundary portion between the condensing portion 17A and the non-condensing portion 17B may have a slightly flat portion. The laser beams LB1 and LB2 reflected from the corners of the polygon mirror 10 are radiated through the non-condensing portion 17B and are irradiated on the surface of the steel plate 20.
[0051]
　As a result, the spot formed on the surface of the steel plate 20 by the laser beams LB1 and LB2 passing through the non-condensing portion 17B has a larger area than the spots S2 and S3 shown in FIG. Therefore, the irradiation intensity of the laser beams LB1 and LB2 on the surface of the steel plate 20 is weaker than that of the embodiments of FIGS. 2 to 6, and the groove is less likely to be formed on the surface of the steel plate 20. Therefore, more uniform groove processing and groove depth can be realized.
[0052]
　Further, FIG. 8 shows a configuration of the groove processing device 300 as the second modification of the present embodiment as viewed from the rolling direction of the steel plate 20. As shown in FIG. 8, the groove processing apparatus 300 includes a shielding plate 19 such as a mask in the optical path of the laser beams LB1 and LB2 that have passed through the non-condensing portion 13B (shielding step). As a result, the laser beams LB1 and LB2 are blocked by the shielding plate 19. The laser beams LB1 and LB2 that have passed through the non-condensing unit 13B have a weaker irradiation intensity than the laser beams LB1 and LB2 that have passed through the condensing lens 12 of FIG. 1B. Therefore, even if the shielding plate 19 is irradiated with the laser beams LB1 and LB2 that have passed through the non-condensing portion 13B, the shielding plate 19 is not damaged much.
[0053]
　Further, by adopting a configuration in which the lens 17 of FIG. 7 and the shielding plate 19 of FIG. 8 are combined, damage to the shielding plate 19 can be further suppressed.
[0054]
　The description content in the present embodiment can be appropriately changed without departing from the spirit of the present invention.
　For example, a mirror may be used instead of the lens as the optical system constituting the groove processing apparatus.
Industrial applicability
[0055]
　According to the present invention, it is possible to provide a grooving apparatus and a grooving method that realize uniform grooving and grooving depth without contaminating the optical component. Therefore, the present invention has extremely high industrial applicability.
Code description
[0056]
10 Polygon mirror
11 Light source device
11A Collimator 13,
17 Lens
13A, 17A Condensing part
13B, 17B Non-condensing part
15 Optical fiber cable
19 Shielding plate
20 Steel plate
100, 200, 300 Grooving device
101, 102 Plane mirror
C1 External circle
LB Laser beam
O1 rotation axis
PL vertical line

WE CLAIMS

A grooving device that forms a groove on the surface of an object by a
　laser beam, from a light source device that outputs the
　laser beam, a polygon mirror that reflects the laser beam output from the light source device, and the
　polygon mirror . An optical system provided in the optical path of the reflected laser beam, which is a light collecting unit that allows the laser beam reflected from one surface of the polygon mirror to pass through and is focused on the surface of the object, and the collection. An optical system provided outside the optical portion and having a non-condensing portion that allows the laser beam reflected from a corner portion straddling two adjacent surfaces of the polygon mirror to pass through and does not focus on the surface of the object. And,
　equipped with a grooving device.
[Claim 2]
　The groove processing apparatus according to claim 1, wherein the non-condensing portion has no focal point.
[Claim 3]
　The groove processing device according to claim 1, wherein the non-condensing portion emits the laser beam reflected from the corner portion of the polygon mirror.
[Claim 4]
　The groove processing apparatus according to any one of claims 1 to 3, further comprising a shielding plate in the optical path of the laser beam that has passed through the non-condensing portion.
[Claim 5]
　It is a groove processing method for forming a groove on the surface of an object
　by a laser beam, in which an output step for outputting the laser beam by a light source device and a
　polygon mirror reflect the laser beam output from the light source device. A reflection step, a
　light collection section passing step in which the laser beam reflected from one surface of the polygon mirror is passed through a light collection unit and focused on the surface of the object, and
　two adjacent surfaces of the polygon mirror. A
　groove provided with a non-condensing portion passing step in which the laser beam reflected from the straddling corner portion is passed through a non-condensing portion provided outside the condensing portion and is not condensed on the surface of the object. Processing method.
[Claim 6]
　The groove processing method according to claim 5, wherein the non-condensing portion has no focus in the non-condensing portion passing step.
[Claim 7]
　The groove processing method according to claim 5, wherein in the non-condensing portion passing step, the laser beam is diverged in the non-condensing portion.
[Claim 8]
　4. The groove processing method according to item 1.