JP2019063817A - Laser processing head - Google Patents

Abstract

To provide a laser processing head that is miniaturized by shortening a length of an optical path.SOLUTION: A laser processing head 1 provided to a laser processing machine includes: a housing 10; a scanning part 50; an optical member 40; a transparent member 60; and a light shielding member 80 for covering a peripheral part S2 while exposing an irradiation region S1 of the transparent member 60. The optical member 40 is provided in a position upstream from the light shielding member 80 in an irradiation direction and overlapping on the light shielding member 80 and the transparent member 60 in the irradiation direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a laser processing head provided in a laser processing apparatus that scans a laser beam and irradiates a workpiece with a print.

  BACKGROUND Conventionally, a laser processing apparatus provided with a laser processing head is known. For example, in the technology described in Patent Document 1, the laser processing head includes a laser light source, a scanning unit, an fθ lens, and the like. The scanning unit two-dimensionally scans the laser light emitted from the laser light source. The fθ lens condenses the laser beam scanned by the scanning unit. By irradiating the processing object with the laser beam, printing (processing) is performed on the processing object.

JP, 2016-68137, A

  The laser beam passes through an fθ lens, which is a member that transmits the laser beam, and emits from the laser processing head. Since the laser beam is emitted in a scanned state by the scanning unit, an fθ lens having a larger area than the scanning area is used so as to cover the entire scanning range of the laser light. Reflected light from the object to be processed may pass through the fθ lens again and enter the laser processing head. The reflected light may penetrate into the laser processing head also from the peripheral portion of the scanning area in the fθ lens.

  In the laser processing head, optical members such as a reflection mirror, a dichroic mirror, and a lens are disposed on the optical path of the laser light in order to adjust the optical path and the beam diameter of the laser light. In general, an optical member for reflecting or transmitting visible light for a guide laser may be installed in the laser processing head. The optical member needs to be disposed at a position where the reflected light entering from the fθ lens does not strike. Since the optical member is disposed at a position separated from the fθ lens, the length of the optical path from the optical member to the fθ lens from the optical member and the visible light is increased, and the entire laser processing head device is enlarged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a laser processing head which has a reduced optical path length and is miniaturized.

  In order to achieve this object, the invention according to claim 1 is a laser processing head provided in a laser processing machine, which is incorporated in a case and a case and scans light emitted from a laser light source. A scanning unit that reflects light in an irradiation direction that is directed to one surface of the casing, and a built-in casing, which is disposed on a path toward light to the scanning unit and in front of the scanning unit. An optical member, a transparent member provided on one surface of the housing for transmitting light scanned by the scanning unit to the outside of the housing, and an area of the transparent member to which the light scanned by the scanning unit is irradiated. A light shielding member that exposes the irradiation region and covers the peripheral portion that is the periphery of the irradiation region and that overlaps the transparent member in the irradiation direction; and the optical member is upstream of the light shielding member in the irradiation direction Light shielding member and light It is provided at a position overlapping with member, and wherein.

  The invention according to claim 2 is the laser processing head according to claim 1, characterized in that the light shielding member is provided separately from the transparent member in the irradiation direction.

  The invention according to claim 3 is the laser processing head according to claim 1 or 2, wherein the light shielding member is disposed upstream of the transparent member in the irradiation direction.

  The invention according to claim 4 is the laser processing head according to any one of claims 1 to 3, wherein the light blocking member is a portion from the light blocking member to the central axis of the irradiation area in the first portion of the light blocking member. It is characterized in that the first distance which is the distance is formed shorter than the second distance which is the distance from the light blocking member to the central axis in the second portion downstream of the first portion in the irradiation direction.

  The invention according to claim 5 is the laser processing head according to any one of claims 1 to 4, further comprising a visible light source for emitting visible light to the optical member, the optical member being a laser light source It is a dichroic mirror that transmits either the emitted light or the light emitted from the visible light source, and reflects the other of the light emitted from the laser light source and the light emitted from the visible light source. Do.

  The invention according to claim 6 is the laser processing head according to any one of claims 1 to 5, further comprising a holding portion for holding the optical member, the holding portion having a smaller thermal conductivity than the housing. It is characterized by having a rate.

  In the laser processing head according to the first aspect of the present invention, the scanning unit is incorporated in the housing, and the transparent member is provided on one surface of the housing. Light from the laser light source is scanned by the scanning unit. The light scanned by the scanning unit passes through the transparent member and is emitted to the outside of the housing. A part of the light emitted to the outside of the housing is reflected by the processing object toward the transparent member. Reflected light may pass through the transparent member and enter the inside of the housing.

  The laser processing head has an optical member in its housing. The optical member is disposed on the path of light emitted from the laser light source toward the scanning unit and in front of the scanning unit.

  The laser processing head of the invention which concerns on Claim 1 has a light-shielding member. The light shielding member is disposed so as to cover the peripheral portion of the transparent member which is the periphery of the irradiation area and which is the area overlapping the transparent member in the irradiation direction, and the light shielding member blocks the reflected light. The range of penetration is limited. Therefore, in the laser processing head according to the first aspect of the present invention, the optical member can be disposed closer to the transparent member as compared to the case where the light shielding member is not provided, and the distance from the transparent member to the optical member is shortened. can do. Therefore, the length of the optical path from the optical member to the transparent member is shortened, and the miniaturization of the entire apparatus is realized.

  In the laser processing head of the invention according to claim 2, the light shielding member is provided separately from the transparent member in the irradiation direction. When the reflected light strikes the light shielding member, the light shielding member has heat. Unlike the laser processing head according to the second aspect of the invention, when there is no gap between the light shielding member and the transparent member and the light shielding member is in contact with the transparent member, heat is transmitted from the light shielding member to the transparent member. The heat may distort or damage the transparent member. The distortion or damage of the transparent member may reduce the printing quality. For example, distortion or damage to the transparent member may cause refraction, scattering, diffraction, absorption, and the like to the laser light, and the laser light may not be irradiated to a position different from the target position or may not reach the intended light intensity. Deterioration of print quality such as print position deviation and print blur occurs.

  When the light blocking member is provided separately from the transparent member, the heat of the light blocking member is less likely to be transmitted to the transparent member. Since distortion and damage of the transparent member due to the influence of heat are less likely to occur, deterioration in printing quality can be suppressed.

  In the laser processing head according to the third aspect of the present invention, the light shielding member is disposed upstream of the transparent member in the irradiation direction. The range to which the laser beam scanned by the scanning unit is irradiated is larger on the downstream surface of the transparent member than on the upstream transparent member in the irradiation direction. When the light shielding member is disposed in the range where the laser irradiation is not performed, the wide range of the transparent member is covered with the light shielding member in the case of arranging on the upstream side surface than in the case of arranging on the downstream side surface. When the light shielding member is disposed on the upstream surface, the reflected light is blocked in a wide range as compared to the case where the light shielding member is disposed on the downstream surface, so the range in which the reflected light penetrates the inside of the housing becomes smaller. Therefore, the distance from the transparent member to the optical member can be shortened as compared with the case where the light shielding member is provided on the downstream surface. Therefore, the length of the optical path from the optical member to the transparent member is shortened, and the miniaturization of the entire apparatus is realized.

  In the laser processing head according to the fourth aspect of the present invention, in the first portion, the first distance, which is the distance from the light blocking member to the central axis of the irradiation region, is downstream of the first portion in the irradiation direction. The second portion is formed shorter than a second distance which is a distance from the light blocking member to the central axis of the irradiation area. The range to which the laser light is irradiated becomes larger as it goes downstream in the irradiation direction. The light blocking member is disposed outside the range to which the scanned laser beam is irradiated so as not to block the laser beam scanned by the scanning unit. The light blocking member can be disposed near the central axis of the irradiation area as it goes upstream in the irradiation direction. The first distance, which is the distance from the light shielding member to the central axis of the irradiation area in the first portion, is the distance from the light shielding member to the central axis of the irradiation area, in the second part downstream of the first portion in the irradiation direction By forming the light shielding member so as to be shorter than two distances, the range covering the transparent member becomes wider compared to the case where the light shielding member is formed so as to make the first distance equal to the second distance. The reflected light entering the housing can be reduced. Therefore, the distance from the optical member to the transparent member can be shortened. Therefore, the length of the optical path from the optical member to the transparent member is shortened, and the miniaturization of the entire apparatus is realized.

  The laser processing head of the invention according to claim 5 further has a visible light source for emitting visible light to the optical member, and the optical member comprises light emitted from the laser light source and light emitted from the visible light source. It is a dichroic mirror that transmits one of the light and reflects the other of the light emitted from the laser light source and the light emitted from the visible light source. The dichroic mirror can be arranged near the transparent member. Therefore, the distance from the dichroic mirror to the transparent member can be shortened. Therefore, the length of the optical path from the dichroic mirror to the transparent member is shortened, and the miniaturization of the entire apparatus is realized.

Moreover, the laser processing head of the invention which concerns on Claim 6 further has a holding | maintenance part holding an optical member, and a holding | maintenance part has thermal conductivity smaller than a housing | casing. The light blocking member is heated by the reflected light incident on the light blocking member being absorbed by the light blocking member. When the holding portion is heated by heat transfer from the light shielding member to the holding portion, the holding portion may be thermally deformed or the like, and positional deviation of the held optical member may occur. In addition, heat may cause damage to the optical member. However, in the laser processing head of the invention according to claim 6, the holder has a thermal conductivity smaller than that of the housing. The heat of the light shielding member is easily transmitted to the highly conductive case, but is hardly transmitted to the low conductive holding portion. Therefore, the thermal damage of the holding portion is suppressed, and the influence of the heat on the optical member is suppressed. Therefore, the distance from the optical member held by the holding portion and the holding portion to the transparent member can be shortened. Therefore, the length of the optical path from the optical member to the transparent member is shortened, and the miniaturization of the entire apparatus is realized.

It is a figure which shows the laser processing apparatus 100 which has the laser processing head 1 which concerns on one Embodiment of this invention. It is a top view showing laser processing head 1 concerning one embodiment of the present invention. It is a side view showing laser processing head 1 concerning one embodiment of the present invention. It is a sectional view showing laser processing head 1 concerning one embodiment of the present invention. It is a top view showing laser processing head 1B concerning other embodiments of the present invention. It is a top view showing laser processing head 1C concerning other embodiments of the present invention. It is a top view showing laser processing head 1D concerning other embodiments of the present invention. It is explanatory drawing explaining the light-shielding member and irradiation area | region in the laser processing head 1 which concerns on other embodiment of this invention.

  Hereinafter, an embodiment in which a laser processing head of the present invention is embodied will be described with reference to the drawings.

  As shown in FIG. 1, the laser processing head 1 according to the present embodiment is provided in a laser processing apparatus 100. The laser processing apparatus 100 includes a controller unit 2 and a laser processing head 1. The laser processing head 1 is connected to the controller unit 2 via a transmission cable C.

  The controller unit 2 is configured by a computer. The controller unit 2 sends various drive control signals to the laser processing head 1 via the signal line of the transmission cable C. The transmission cable C may be configured to include an optical fiber or the like.

  The laser processing head 1 irradiates the processing object W with the laser beam L based on the drive control signal received from the controller unit 2 and two-dimensionally scans the laser light L to print on the processing object W ( Do processing).

<Laser processing head>
Next, a schematic configuration of the laser processing head 1 will be described based on FIG. 1, FIG. 2, FIG. 3 and FIG. 4. In the description of the laser processing head 1, the left direction, the right direction, the upper direction, and the lower direction in FIG. 2 are the front direction, the rear direction, the left direction, and the right direction of the laser processing head 1. The upper and lower directions in FIG. 3 are the upper and lower directions of the laser processing head 1. The up and down direction is orthogonal to the front and back direction and the left and right direction. Therefore, the direction in which the laser beam L is emitted from the laser processing head 1 toward the processing target W is the downward direction. FIG. 2 is a top view of the laser processing head 1. FIG. 3 is a side view of the laser processing head 1. FIG. 4 is a cross-sectional view of the laser processing head 1 when the cross section A-A in FIG. 2 is viewed in the A direction.

  As shown in FIG. 1, the laser processing head 1 includes a housing 10 configured of a base plate 11 and a cover 12. The housing 10 has a substantially rectangular parallelepiped shape. FIG. 1 shows the cover 12 attached to the base plate 11, and FIGS. 2, 3 and 4 show the cover 12 removed from the base plate 11. As shown in FIG. The base plate 11 and the cover 12 are formed of, for example, a metal such as aluminum. The cover 12 is disposed on the top of the base plate 11.

  As shown in FIGS. 2, 3 and 4, the laser processing head 1 includes a light source 20, a beam expander 30, a dichroic mirror 40, a scanning unit 50, a visible light source 70, a light shielding member 80 inside the housing 10. A holding unit 90 is provided, and a lens unit 600 is provided on the base plate 11 which is the lower surface of the housing 10.

  The light source 20 is, for example, a passive Q-switched laser and fixed on the base plate 11. A passively Q-switched laser has, for example, a neodymium-doped yttrium aluminum garnet (Nd: YAG) crystal as a laser medium. The passive Q-switched laser excites the laser medium by incidence of excitation light emitted from an excitation light source (not shown), and oscillates pulsed laser light L. The light source 20 is not limited to the passive Q-switched laser using the above-described Nd: YAG as a laser medium, and may be another light source. For example, a light source using an Nd: GdVO4 crystal or an Nd: YVO4 crystal as a laser medium may be used, or a gas laser using carbon dioxide gas as a medium may be used.

  The beam expander 30 is provided coaxially with the laser beam L oscillated from the light source 20. The beam expander 30 is configured to include a plurality of lenses, and changes the beam diameter of the laser light L. In the present embodiment, the light source 20 and the beam expander 30 are disposed inside the housing 10, but the positions at which the light source 20 and the beam expander 30 are disposed are not limited thereto, and the light source 20 and the beam expander 30 may be disposed outside the housing 20. It may be arranged. For example, the light source 20 and the beam expander 30 are disposed in the controller unit 2, and the laser light L emitted from the light source 20 and the beam expander 30 is incident on the laser processing head 1 through the optical fiber of the transmission cable C. It may be

  The dichroic mirror 40 is fixed to the base plate 11 via the holding unit 90. The dichroic mirror 40 is disposed on the optical path of the laser light L emitted from the beam expander 30. The dichroic mirror 40 is disposed to form an angle of 45 degrees in the diagonally right forward direction with respect to the light path of the laser light L emitted from the beam expander 30. The dichroic mirror 40 transmits substantially all of the laser light L.

  The visible light source 70 is configured of, for example, a semiconductor laser that emits red laser light as the visible laser light M. The visible light source 70 is disposed in the left direction of the dichroic mirror 40. The visible laser light M emitted from the visible light source 70 is incident on the dichroic mirror 40 at an incident angle of 45 degrees, and is reflected at a reflection angle of 45 degrees. The optical path of the visible laser light M reflected by the dichroic mirror 40 matches the optical path of the laser light L that has passed through the dichroic mirror 40. The visible laser beam M is used as a guide that indicates the position where the laser beam L is scanned.

  The scanning unit 50 is attached to the upper side of the through hole 111 formed at the front end of the base plate 11, and the laser light L emitted from the light source 20 and the visible laser emitted from the visible light source 70 and reflected by the dichroic mirror 40 The light M is reflected toward the through holes 111 of the lower base plate 11 to perform two-dimensional scanning. The laser beam L reflected by the scanning unit 50 is directed from the scanning unit 50 to the through hole 111 of the base plate 11 and emitted to the outside of the laser processing head 1. The scanning unit 50 includes a galvano X axis motor 52 having a galvano X axis mirror 51, a galvano Y axis motor 54 having a galvano Y axis mirror 53, and a main body 55. The galvano X-axis motor 52 and the galvano Y-axis motor 54 are attached to the main body 55 by being fitted into and held by the respective mounting holes from the outside so that the respective motor axes are orthogonal to each other.

  In the galvano Y-axis motor 54, the galvano Y-axis mirror 53 is attached to the tip of the motor shaft as a scanning mirror, and the laser beam L and the visible laser beam M are Y in the processing area on the surface of the object W It is used when scanning in the axial direction. In the galvano X-axis motor 52, the galvano X-axis mirror 51 is attached to the tip of the motor shaft as a scanning mirror, and processes the laser beam L and the visible laser beam M reflected by the galvano Y-axis mirror It is used when scanning in the X-axis direction in the processing area on the surface of the object W.

  Therefore, in the scanning unit 50, the galvano X-axis motor 52 and the galvano X-axis mirror 51 and the galvano Y-axis mirror 53 attached to the tip of each motor shaft of the galvano Y-axis motor 54 face each other inside. The rotation of the galvano X-axis motor 52 and the galvano Y-axis motor 54 is controlled to rotate the galvano X-axis mirror 51 and the galvano Y-axis mirror 53 so that the laser beam L and the visible laser beam M are directed downward. Two-dimensional scan. The two-dimensional scanning direction is the left-right direction (X-axis direction) and the front-rear direction (Y-axis direction) in the processing area of the surface of the processing target W.

  In the scanning unit 50, the range in which the galvano X-axis motor 52 and the galvano Y-axis motor 54 rotate is determined such that the irradiation range in the processing area is a predetermined range. In this embodiment, an area that is 120 mm in the X-axis direction and 120 mm in the Y-axis direction in the processing area is the irradiation area in the processing area. A path of the laser beam L and the visible laser beam M reflected by the scanning unit 50 toward the center of the irradiation range in the processing area is shown in FIG. 4 as a central axis T1. The paths toward the front end and the rear end of the laser beam L and the visible laser beam M reflected by the scanning unit 50 toward the front end and the rear end of the irradiation range in the processing area are shown in FIG. 4 as paths T2 and T3. . An area between the path T2 and the path T3 is an area to which the laser beam L and the visible laser beam M can be irradiated by the rotation of the galvano Y-axis motor 54. The direction in which the laser beam L and the visible laser beam M reflected by the scanning unit 50 are directed from the scanning unit 50 to the through holes 111 of the base plate 11 and reaches the central position of the processing area is taken as the irradiation direction. Therefore, the irradiation direction of the present invention is a direction along the central axis T1. The irradiation range in the processing area is not limited to the above range, and may be another range.

  The lens unit 600 has a circular shape in plan view, and is disposed inside the through hole 111 of the base plate 11. The lens unit 600 includes an fθ lens 60 and a lens barrel 65. The lens barrel 65 has a substantially cylindrical shape, and holds the fθ lens 60 inside the cylinder. The fθ lens 60 has a circular shape in plan view. The fθ lens 60 is provided at a position at which the end face 61 of the fθ lens 60 on the scanning unit 50 side is separated from the scanning unit 50 in the irradiation direction from the end face of the base plate 11 on the scanning unit 50 side. The fθ lens 60 is provided at a position where the end face 62 opposite to the scanning unit 50 of the fθ lens 60 is separated from the scanning unit 50 in the irradiation direction from the end face opposite to the scanning unit 50 of the base plate 11. The fθ lens 60 coaxially condenses the laser beam L and the visible laser beam M two-dimensionally scanned by the scanning unit 50 on the processing area of the surface of the processing target W. The laser beam L and the visible laser beam M reflected by the scanning unit 50 pass through the fθ lens 60 and are emitted to the outside of the laser processing head 1. The fθ lens 60 functions as a transparent member in the present invention. By controlling the rotation of the galvano X-axis motor 51 and the galvano Y-axis motor 52, the laser beam L and the visible laser beam M are on the surface of the object to be machined W with the desired machining pattern in the front-rear direction (Y-axis direction) Two-dimensional scanning is performed in the left-right direction (X-axis direction).

  The fθ lens 60 is formed such that the entire surface at the end face 61 is a transparent region S3 that can transmit light. Therefore, the reflected light reflected by the processing target W may pass through the transparent area S3 of the fθ lens 60 and may enter the area upstream of the fθ lens 60 in the irradiation direction. Further, as described above, in the scanning unit 50, the range to be two-dimensionally scanned is determined so that the laser light L and the visible laser light M are irradiated within the irradiation range in the processing area. Therefore, when the laser light L and the visible laser light M are irradiated within the irradiation range in the processing area, the laser light L and the visible laser light M are irradiated to the area shown by the irradiation area S1 on the end face 61 of the fθ lens 60 Ru. As shown in FIG. 4, the irradiation area S1 is an area between the path T2 and the path T3 in the Y-axis direction. The irradiation area S1 is a substantially rectangular area as viewed from above as shown in FIG. The peripheral region S2 around the irradiation region S1 on the end face 61 of the fθ lens 60 can transmit the laser beam L and the visible laser beam M, but the laser beam L and the visible laser beam M scanned by the scanning unit 50 are irradiated It is an area that is not Therefore, the reflected light and the like reflected by the processing target W may pass through the peripheral region S2 of the fθ lens 60 and intrude into the region on the upstream side of the fθ lens 60 in the irradiation direction.

  The light shielding member 80 is made of, for example, a metal such as aluminum. The light blocking member is painted black to prevent light reflection. The light shielding member 80 is formed as a square-shaped flat plate whose outer shape viewed from above is rectangular and has a rectangular opening 82 at the center. The light blocking member 80 is disposed above the through hole 111 of the base plate 11 and between the base plate 11 and the scanning unit 50 in the irradiation direction. The light shielding member 80 is fixed to the base plate 11 by mounting screws 81a, 81b, 81c, and 81d. The light blocking member 80 contacts the base plate 11 by being fixed to the base plate 11. Therefore, the light shielding member 80 is disposed upstream of the fθ lens 60 in the irradiation direction and at a distance from the fθ lens 60. The light shielding member 80 is disposed at a position overlapping the peripheral region S2 in the irradiation direction. The light blocking member 80 is disposed such that the opening 82 is located above the irradiation area S1. The laser beam L and the visible laser beam M scanned by the scanning unit 50 pass through the opening 82 and travel downward from the light shielding member 80. The light blocking member 80 is disposed at a position not intersecting the paths of the laser beam L and the visible laser beam M scanned by the scanning unit 50, and the laser beam L and the visible laser beam M scanned by the scanning unit 50 are fθ lenses It does not prevent reaching 60.

  As shown in FIG. 4, in the light shielding member 80, the size of the opening 82 increases in the irradiation direction. In other words, in the light shielding member 80, the first distance W1 which is the distance from the first end 801 which is the upstream end in the irradiation direction and close to the central axis T1 to the central axis T1 is the downstream in the irradiation direction It is formed shorter than a second distance W2 which is a distance from the second end portion 802 which is an end portion close to the central axis T1 and the central axis T1.

  The holding unit 90 is made of, for example, stainless steel, and holds the dichroic mirror 40. The holder 90 has an opening 901 at one end close to the base plate 11 and an opening 902 at the other end. The holding portion 90 is fixed to the base plate 11 by inserting the mounting screw 91 into the opening 901. By fixing the holding unit 90 to the base plate 11, the opening 902 is disposed on the optical path of the laser light L emitted from the beam expander 30. At this time, the opening 902 is located upstream of the light shielding member 80 in the irradiation direction and at a position overlapping the peripheral region S2 of the light shielding member 80 and the fθ lens 60 in the irradiation direction. The holding unit 90 holds the dichroic mirror 40 at the other end. The holding unit 90 fixes the dichroic mirror 40 with an adhesive or the like. Therefore, the dichroic mirror 40 is positioned upstream of the light shielding member 80 in the irradiation direction by being held by the holding unit 90 and positioned at a position overlapping the light shielding member 80 and the peripheral region S2 of the fθ lens 60 in the irradiation direction.

<Summary>
As described above, the laser processing head 1 according to the present invention includes the light shielding member 80 disposed to expose the irradiation area S1 of the fθ lens 60 and to cover the peripheral area S2 of the fθ lens 60. When the light shielding member 80 exposes the irradiation area S1, the laser beam L and the visible laser light M scanned by the scanning unit 50 are irradiated to the irradiation area S1 without being blocked by the light shielding member 80, and a predetermined area is formed in the processing area. Two-dimensional scan in the range. When the light shielding member 80 covers the peripheral region S2 of the fθ lens 60, the light shielding member blocks the reflected light passing through the peripheral region S2 and directed to the inside of the housing, and the range in which the reflected light penetrates into the housing is limited. . For example, the light blocking member 80 prevents the reflected light that has passed through the peripheral region S2 of the reflected light traveling in the direction opposite to the irradiation direction from further advancing in the opposite direction. Therefore, the reflected light traveling in the opposite direction is prevented from invading the upper region of the light shielding member 80 at a position overlapping the peripheral region S2 of the fθ lens 60 and the light shielding member 80 in the irradiation direction. Even when the dichroic mirror 40 is disposed at a position overlapping the peripheral region S2 of the fθ lens 60 and the light shielding member 80 in the irradiation direction, the reflected light traveling in the opposite direction does not strike the dichroic mirror 40. The dichroic mirror 40 can be disposed close to the fθ lens 60, and the distance from the dichroic mirror 40 to the fθ lens 60 can be shortened. Accordingly, the length of the optical path from the dichroic mirror 40 to the fθ lens 60 is shortened, and the downsizing of the entire laser processing head 1 is realized.

  Further, in the laser processing head 1 according to the present invention, the light shielding member 80 is provided separately from the fθ lens 60 in the irradiation direction. Since the light blocking member 80 is provided separately from the fθ lens 60, the heat of the light blocking member 80 is less likely to be transmitted to the fθ lens 60. Since the fθ lens 60 is less likely to be distorted or damaged by heat, deterioration in printing quality can be suppressed.

  Further, in the laser processing head 1 according to the present invention, the holding portion 90 is formed of stainless steel, and the base plate 11 is formed of aluminum. That is, the holding unit 90 has a thermal conductivity smaller than that of the housing 10. The light blocking member 80 is heated by absorbing the incident reflected light. When the heat is transferred from the light blocking member 80 to the holding portion 90, the holding portion 90 may be thermally deformed or the like, and the positional deviation of the held dichroic mirror 40 may occur. In addition, heat may cause damage to the optical member. However, in the laser processing head 1 according to the present invention, since the holding unit 90 has a smaller thermal conductivity than the housing 10, the heat of the light shielding member 80 is transmitted to the housing 10 and hardly transmitted to the holding unit 90. Therefore, even if the holding portion 90 and the light shielding member 80 are disposed close to each other, the thermal damage to the holding portion 90 is suppressed, and the influence of the heat on the dichroic mirror 40 is suppressed. A member 80 can be arranged. In the present embodiment, the holding portion 90 is formed of stainless steel and the base plate 11 is formed of aluminum, but this is an example, and the holding portion 90 and the base plate 11 are formed of other materials. May be If the holding portion 90 is formed to have a thermal conductivity smaller than that of the housing 10, the same effect can be obtained. For example, the holding portion 90 may be formed of resin and the base plate 11 may be formed of metal.

  Next, the shape of the light shielding member 80 in the present invention will be described. As described above, in the laser processing head 1 according to the present invention, the end on the opening 82 side of the light shielding member 80 is formed to be inclined with respect to the irradiation direction, and from the central axis T1 toward the downstream of the irradiation direction. It is formed to be separated. In other words, the inner peripheral surface of the light shielding member 80 forming the opening 82 of the light shielding member 80 is formed to be inclined with respect to the irradiation direction, and the distance between the inner peripheral surfaces opposed in the direction perpendicular to the irradiation direction is the irradiation direction The downstream side is formed to be larger than the upstream side. That is, the light shielding member 80 is formed such that the first distance W1, which is the distance from the first end 801 to the central axis T1, is shorter than the second distance W2, which is the distance from the second end 802 to the central axis T1. Ru. The range irradiated with the laser beam L and the visible laser beam M scanned by the scanning unit 50 becomes smaller toward the upstream in the irradiation direction. The light blocking member 80 can be disposed near the central axis of the irradiation area as it goes upstream in the irradiation direction. In the present invention, since the light shielding member 80 is disposed upstream of the fθ lens 60 in the irradiation direction, the size of the opening 82 is smaller than the size of the irradiation area S1. The light blocking member 80 can cover a wider range as compared with the case where the size of the opening 82 is equal to the size of the irradiation area S1, and can block more reflected light. Further, in the light shielding member 80 in the present invention, the first distance W1 is formed shorter than the second distance W2, and the size at the upstream in the opening 82 is smaller than the size at the downstream in the irradiation direction. The opening 82 in the present invention has a rectangular shape in top view, but the length of one side of the opening 82 in the upstream in the irradiation direction is larger than the length of one side of the opening 82 in the downstream . The optical member 80 can cover a wider area in the upstream of the opening 82 than in the downstream, and can block more reflected light. Therefore, the distance from the fθ lens 60 to the dichroic mirror 40 can be shortened. Therefore, the length of the optical path from the dichroic mirror 40 to the fθ lens 60 is shortened, and the miniaturization of the laser processing head 1 is realized. The shape of the light shielding member 80 is not limited to the shape in which the end on the side of the opening 82 described above is inclined, but may be another shape. For example, the diameter of the opening 82 may differ stepwise in the irradiation direction, and may have a step-like shape such that the diameter decreases toward the upstream in the irradiation direction. In this case, for example, the inner circumferential surface forming the opening 82 of the light shielding member 80 is formed such that the distance from the central axis T1 differs between the upstream and the downstream in the irradiation direction, and the inner circumferential surface upstream of the irradiation direction is Alternatively, it may be formed in a step shape in which the distance to the central axis T1 is smaller than the inner peripheral surface downstream of the irradiation direction. Further, for example, the opening 82 may be formed in a shape such that the distance from the end to the central axis T1 is always constant.

  In the above embodiment, the laser processing apparatus 100 is an example of a laser processing machine in the present invention. The housing 10 is an example of a housing in the present invention, and the base plate 11 is an example of one surface of the housing in the present invention. The light source 20 is an example of the laser light source in the present invention. The scanning unit 50 is an example of a scanning unit in the present invention. The irradiation direction is an example of the irradiation direction in the present invention. The dichroic mirror 40 is an example of the optical member and the dichroic mirror in the present invention. The fθ lens 60 is an example of the transparent member in the present invention. The irradiation area S1 is an example of the irradiation area in the present invention, and the peripheral area S2 is an example of the peripheral portion in the present invention. The light shielding member 80 is an example of the light shielding member in the present invention. The first end 801 is an example of a first portion in the present invention, and the second end 802 is an example of a second portion in the present invention. The first distance W1 is an example of a first distance in the present invention, and the second distance W2 is an example of a second distance in the present invention. The central axis T1 is an example of the central axis in the present invention. The visible light source 70 is an example of the visible light source in the present invention. The holding unit 90 is an example of the holding unit in the present invention. The laser light L and the visible laser light M are examples of light in the present invention.

  The present invention is of course not limited to the above-described embodiment, and various improvements and modifications are possible. In the following description, the same reference numerals as those of the configuration and the like of the laser processing head 1 of the above-described embodiment indicate the same or corresponding portions as the configuration and the like of the above-described embodiment.

<Modification 1>
In the above-described embodiment, the optical member disposed on the path toward the scanning unit 50 and immediately before the scanning unit 50 on the path toward the scanning unit 50 is the dichroic mirror 40. Is not limited to this. As the optical member, various members that affect light by reflecting, transmitting, diffusing, diffracting, refracting, controlling polarization, etc. with respect to light are applied.

  For example, as shown in FIG. 5, the lens 41 of the beam expander 30 is an optical member disposed on the path toward the scanning unit 50 and in front of the scanning unit 50, in which light emitted from the laser light source is directed. It is also good. The laser processing head 1B shown in FIG. 5 does not have a dichroic mirror or a visible light source, and the laser light L emitted from the beam expander 30 enters the scanning unit 50. The beam expander 30 has a convex lens 41 a and a concave lens 41 b. The convex lens 41a and the concave lens 41b are disposed along the optical axis. The diameter of the laser beam L is changed by the convex lens 41 a and the concave lens 41 b.

  The convex lens 41a is disposed at a position overlapping the peripheral region S2 of the fθ lens 60 and the light shielding member 80 in the irradiation direction. The convex lens 41 a is disposed near the fθ lens 60, and the distance from the convex lens 41 to the fθ lens 60 can be shortened. Therefore, the length of the optical path from the convex lens 41 a to the fθ lens 60 is shortened, and the miniaturization of the entire apparatus is realized.

<Modification 2>
Also, for example, as shown in FIG. 6, the reflection mirror 43 may be an optical member disposed on the path toward the scanning unit 50 and in front of the scanning unit 50, in which the light emitted from the laser light source is directed. . The laser processing head 1C shown in FIG. 6 does not have a dichroic mirror or a visible light source, and the laser beam L emitted from the beam expander 30 is reflected by the reflection mirror 42 and the reflection mirror 43 and enters the scanning unit 50. The reflection mirror 42 is disposed in front of the light source 20 and the expander 30 so as to form an angle of 45 degrees with respect to the optical path of the laser light L. The reflection mirror 42 reflects the incident laser light L in the right direction. The reflection mirror 43 is disposed on the light path of the laser light L reflected by the reflection mirror 42 at an angle of 45 degrees with respect to the light path of the reflected laser light L. The reflection mirror 43 reflects the incident laser light L in the forward direction, and guides the laser light L to the scanning unit 50.

  The reflection mirror 43 is disposed at a position overlapping the peripheral region S2 of the fθ lens 60 and the light shielding member 80 in the irradiation direction. The reflection mirror 43 is disposed near the fθ lens 60, and the distance from the reflection mirror 43 to the fθ lens 60 can be shortened. Therefore, the length of the optical path from the reflection mirror 43 to the fθ lens 60 is shortened, and the miniaturization of the entire apparatus is realized.

<Modification 3>
Also, for example, as shown in FIG. 7, the beam splitter 44 may be an optical member disposed on the path toward the scanning unit 50 and in front of the scanning unit 50, in which the light emitted from the laser light source is directed. . The laser processing head 1D shown in FIG. 7 does not have a dichroic mirror or a visible light source, and has a beam splitter 44 and a detector 75. In the laser processing head 1 D, the laser beam L emitted from the beam expander 30 passes through the beam splitter 44 and is incident on the scanning unit 50. The beam splitter 44 is disposed in front of the light source 20 and the expander 30 so as to form an angle of 45 degrees with respect to the optical path of the laser light L. The beam splitter 44 transmits a part of the incident laser light L and guides it to the forward scanning unit 50, and reflects a part to the right. The detector 75 is disposed to the right of the beam splitter 44. The detector 75 receives the laser beam L reflected by the beam splitter 44 and detects the intensity or the like of the laser beam L.

  The beam splitter 44 is disposed at a position overlapping the peripheral region S2 of the fθ lens 60 and the light shielding member 80 in the irradiation direction. A beam splitter 44 can be placed near the fθ lens 60 to reduce the distance from the beam splitter 44 to the fθ lens 60. Therefore, the length of the optical path from the beam splitter 44 to the fθ lens 60 is shortened, and the miniaturization of the entire apparatus is realized.

<Modification 4>
Moreover, in the above-mentioned embodiment, although irradiation area | region S1 is substantially rectangular and showed the example which has the light shielding member 80 which has the rectangular opening 82, an irradiation area | region and a light shielding member are not restricted to this. For example, as shown in FIG. 8, it may be smaller than the circular transparent area S3E as viewed from the top, and may be a circular irradiation area S1E as viewed from the top. In this case, the peripheral area S2E is an area around the irradiation area S1E. Although distortion may be greater at the end portion of the lens than at the central portion, by setting only the vicinity of the center of the transparent region S3E as the irradiation region S1E, only a portion with small distortion can be used. At this time, a light shielding member 80E having a circular opening 82E may be used as the light shielding member. By providing the circular opening 82E of the light shielding member 80E, it is possible to widen the range covered by the light shielding member 80E while exposing the irradiation area S1E.

  Moreover, in the above-mentioned embodiment, although the example in which the light shielding member 80 covers the whole region of peripheral region S2 was shown, the light shielding member may cover only a part of peripheral region S2 not only this. For example, as shown in FIG. 8, when the irradiation area S1F is rectangular as viewed from the top and the periphery thereof is the peripheral area S2F, the light shielding member may be a light shielding member 80E covering half of the peripheral area S2F as a light shielding member.

  Moreover, in the above-mentioned embodiment, although the irradiation area | region S1 showed the example which is substantially rectangular corresponding to an irradiation range in a process area | region being a rectangle, it does not restrict to this. In order to make the irradiation range in the processing area rectangular in consideration of the optical path distortion by the fθ lens 60, the scanning range of the scanning unit 50 may be determined such that the irradiation area S1 has a predetermined shape.

<Other Modifications>
In the above-described embodiment, the light shielding member 80 is disposed above the fθ lens 60. However, the light shielding member is not limited to this and may be disposed below the fθ lens 60. As described above, since the irradiation range of the light scanned by the scanning unit 50 becomes wider toward the bottom, when the light shielding member 80 is disposed above the fθ lens 60 as in the above embodiment, the light shielding member is wider It can cover the range. However, even in the case where the light shielding member is disposed below the fθ lens 60, it is possible to reduce the reflected light entering the inside of the housing 10 as compared with the case where the light shielding member is not provided. Further, when the light shielding member is disposed below the fθ lens 60, for example, the light shielding member can be provided outside the housing 10, and replacement of the light shielding member with respect to the housing 10 becomes easy.

  In the above embodiment, the transparent member provided on the lower surface of the housing 10 and transmitting the light scanned by the scanning unit 50 to the outside of the housing 10 is the fθ lens 60. The members are not limited to this. The transparent member may be a member capable of transmitting laser light or visible light, and may be, for example, a lens such as a telecentric lens, or a simple window made of a transparent member having no light focusing function. May be Even if the transparent member is a window, for example, by emitting the laser beam L while adjusting the lens of the beam expander 30, the laser beam L can be converged on the focal plane and printed on the workpiece W .

  Moreover, in the above-mentioned embodiment, although the example in which the holding | maintenance part 90 contacts the light shielding member 80 was shown, it does not restrict to this. For example, the holding portion 90 may be disposed apart from the light shielding member 80. When the holding portion 90 and the light shielding member 80 are spaced apart, heat conduction from the light shielding member 80 to the holding portion 90 is suppressed. In addition, for example, a heat insulating material may be disposed between the holding portion 90 and the light shielding member 80. In this case, heat conduction from the light shielding member 80 to the holding portion 90 is suppressed by the heat insulating material. Since the thermal damage to the holding portion 90 is suppressed and the influence of heat on the dichroic mirror 40 is suppressed, the holding portion 90 can be disposed close to the light shielding member 80.

  Moreover, although the example in which the holding part 90 contacts the base plate 11 was shown in the above-mentioned embodiment, it does not restrict to this. For example, the heat insulating material is disposed between the holding portion 90 and the base plate 11, or the heat insulating material is disposed between the holding portion 90 and the mounting screw 91, etc. It is good also as composition which controls heat conduction between them. In this case, the heat conduction from the base plate 11 to the holding portion 90 is suppressed by the heat insulating material. For example, since the heat transmitted from the light shielding member 80 to the base plate 11 is further suppressed from being transmitted to the holding portion 90, even if the light shielding member 80 or the base plate 11 is heated by the reflected light, the heat of the holding portion 90 Damage is suppressed, and the influence of heat on the dichroic mirror 40 is suppressed. Therefore, the holding portion 90 can be disposed close to the light shielding member 80.

Reference Signs List 100 laser processing apparatus 1, 1B, 1C, 1D laser processing head 2 controller unit C transmission cable 10 housing 11 base plate 20 light source 30 beam expander 40 dichroic mirror 50 scanning unit 60 fθ lens 70 visible light source 80, 80E, 80F light blocking member 90 holding portion 801 first end portion 802 second end portion W1 first distance W2 second distance S1, S1E, S1F irradiation area S2, S2E, S2F peripheral area T1 central axis S3 transparent area L laser light M visible laser light W processing Object 41a Convex lens 41b Concave lens 42 Reflection mirror 43 Reflection mirror 44 Beam splitter

Claims (6)

A laser processing head provided to a laser processing machine, comprising:
And
A scanning unit which is built in the housing and scans light emitted from a laser light source and reflects the light in an irradiation direction which is a direction toward the one surface of the housing;
An optical member incorporated in the housing and disposed on a path toward the scanning unit, wherein the light emitted from the laser light source is directed to the scanning unit, and immediately before the scanning unit;
A transparent member provided on one surface of the housing for transmitting the light scanned by the scanning unit to the outside of the housing;
An exposed area which is an area to be irradiated with the light scanned by the scanning section of the transparent member is exposed, and a peripheral area which is an area around the irradiated area and which overlaps the transparent member in the irradiation direction A light shielding member covering the
The laser processing head according to claim 1, wherein the optical member is provided upstream of the light shielding member in the irradiation direction and at a position overlapping the light shielding member and the transparent member in the irradiation direction.   The laser processing head according to claim 1, wherein the light shielding member is provided separately from the transparent member in the irradiation direction.   The laser processing head according to claim 1, wherein the light shielding member is disposed upstream of the transparent member in the irradiation direction.   The light shielding member is a first portion of the light shielding member, and a first distance which is a distance from the light shielding member to a central axis of the irradiation region is a second portion downstream of the first portion in the irradiation direction. The laser processing head according to any one of claims 1 to 3, wherein the laser processing head is formed shorter than a second distance which is a distance from the light shielding member to the central axis. And a visible light source for emitting visible light to the optical member,
The optical member transmits any one of the light emitted from the laser light source and the light emitted from the visible light source, and the other of the light emitted from the laser light source and the light emitted from the visible light source The laser processing head according to any one of claims 1 to 4, which is a dichroic mirror that reflects light. It further has a holding portion for holding the optical member,
The laser processing head according to any one of claims 1 to 5, wherein the holding portion has a thermal conductivity smaller than that of the housing.

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