JPH0637809U - Laser injection unit - Google Patents

Abstract

(57) [Summary] [Purpose] To make focus adjustment easy and accurate, and to avoid repeating centering position adjustments. [Constitution] A guide groove 32 extending parallel to the optical axis is formed in the cylindrical portion 10a of the unit main body 10.
The bolt 34 through the screw hole 18a of the lens holding portion 18
Screw on. A support ring 40 is rotatably fitted on the other end (right end) of the unit body 10, and a position adjusting ring 42 is integrally attached to the support ring 40. A screw thread 42a is cut on the inner peripheral surface of the position adjusting ring 42, and the screw thread 42a is screwed with the screw thread 18a on the outer peripheral surface of the lens holding portion 18. When the position adjusting ring 42 is turned, the lens holding part 18 moves in the optical axis direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laser incidence unit that causes a laser beam from a laser oscillator to enter one end face of an optical fiber.

[0002]

[Prior art]

 FIG. 4 shows the configuration of a typical conventional laser incidence unit used in a laser processing apparatus. In this laser incidence unit, one end of the optical fiber 102 is attached to the optical fiber attachment portion 104 at one end (the left end in FIG. 4) of the unit main body 100, and the unit main body 100 is fed from the laser oscillator (not shown) side. The laser light LB that has entered the other end (the right end in FIG. 4) of the laser beam passes through the condenser lens 106 held by the cylindrical lens holder 108 and is converged and incident on one end surface of the optical fiber 102. It is like this.

A receptacle 110 for receiving one end of the optical fiber 102 is provided at the center of the optical fiber mounting portion 104. The tips of the X-direction position adjusting screw 112 and the coil spring 114 oppose and abut against the outer surface of the receptacle 110, and the Y-direction position adjusting screw and the coil spring (not shown) respectively. Also abut against each other. By rotating the knobs (heads) of the X-direction position adjusting screw 112 and the Y-direction position adjusting screw, the position of the receptacle 110 in the XY direction is adjusted, and by extension, the end face of the optical fiber 102 in the XY direction is adjusted. Can be aligned.

A screw thread 108 a is formed on the outer wall surface of the lens holding portion 108 from the intermediate portion to the other end portion, and also on the inner wall surface of the unit main body 100 facing the screw thread 108 a of the lens holding portion 108. Threads 100a are formed and these threads 108a, 100a are screwed together. A lens position adjusting ring 108b is integrally provided at the other end of the lens holding portion 108. When the ring 108b is gripped by a hand and rotated, the lens holding portion 108 rotates with respect to the unit main body 100. It is designed to move in the optical axis direction (Z direction). The movement direction corresponds to the rotation direction. For example, when the ring 108b is rotated clockwise, the lens holding unit 108 moves to one end side (left side) of the unit, and when the ring 108b is rotated counterclockwise, the lens holding unit 108 is moved to the unit. It is designed to move to the other end (right side).

As described above, by rotating the ring 108 b, the lens holding unit 108 can be moved in the optical axis direction (Z direction), and the focus of the condenser lens 106 can be adjusted to the end face of the optical fiber 102. Between the other end (right end) 100b of the unit main body 100 and the position adjusting ring 108b, a lock ring 116 for fixing (locking) the position of the lens holding portion 108 is provided on the thread 108a of the lens holding portion 108. It is screwed together. When the lock ring 116 is screwed so as to press it against the other end 100b of the unit main body 100, the pressing force causes the screw thread 100a of the unit main body 100 and the screw thread 108a of the lens holding portion 108 to strongly press each other, and The part 108 cannot rotate and cannot move. As a result, the position of the condenser lens 106 in the optical axis direction (Z direction) is fixed.

[0006]

[Problems to be solved by the device]

 In this type of laser incidence unit, it is essential that the laser light that has passed through the condenser lens be accurately incident on the center of the end face of the optical fiber. In the case of high-power laser light used for laser processing, if the light is not focused and incident accurately, not only will the incidence efficiency be reduced, but the fiber end face may also be burned, so accurate alignment cannot be achieved. Needed. For accurate alignment, the distance between the condenser lens and the end face of the optical fiber should match the focal length of the lens, and the optical lens and the optical fiber should be aligned, that is, they should be placed on the same axis. Achieved by

In the conventional laser incidence unit as described above, the lens holding unit 108 screwed to the unit main body 100 is rotated and moved in the optical axis direction (Z direction), whereby the lens holding unit is moved. The focusing lens 106 in 108 was moved in the optical axis direction to adjust the focus. However, since the focus of the condenser lens 106 also rotates with such rotation of the lens holding unit 108, even if the centering adjustment is made on the receptacle 110 side, the focus is still on the optical fiber at the focus adjustment stage. Since the center of the end face of 102 was displaced, it was necessary to adjust the centering of the receptacle 110 again.

Further, in the above-described conventional laser incidence unit, after the focus adjustment, the lock ring 116 is pressed against the other end 100b of the unit main body 100 to fix the positions of the lens holding portion 108 and the collecting lens 106. However, since the pressing force from the lock ring 116 acts in the axial direction, the lens holding unit 108 may be displaced or tilted in the axial direction, so that the condenser lens 106 is accurately fixed at the focus adjusted position. Was difficult.

The present invention has been made in view of the above problems, and provides a laser incidence unit in which focus adjustment can be performed easily and accurately and the alignment position adjustment need not be repeated many times. The purpose is to

[0010]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the first laser incidence unit of the present invention has one end of an optical fiber detachably attached to one end of a unit body, and comes in from the other end side of the unit body. An optical fiber for adjusting the mounting position of one end of the optical fiber in a direction perpendicular to the optical axis in a laser incidence unit in which laser light is condensed by an optical lens and is incident on one end face of the optical fiber. With respect to the unit main body, there are alignment adjusting means, a cylindrical lens holding means that holds the optical lens on the inner side surface, has a threaded portion on the outer side surface, and is loosely fitted in the unit main body, and the unit main body. And a guide portion for moving the lens holding means only in the optical axis direction, and a screw portion screwed with a screw portion on an outer surface of the lens holding means, and rotatably attached to the unit main body. Re It has a configuration comprising a grayed-shaped lens position adjusting means.

A second laser incidence unit of the present invention is the first laser incidence unit of the first laser incidence unit, wherein a bolt guide groove is formed on a side surface of the unit body, and the lens holder is attached to the lens holder via the bolt guide groove. The guide means is composed of a screwed bolt, and the lens holder is pressed and fixed to the unit body by tightening the bolt.

[0012]

[Action]

 In the first laser incidence unit of the present invention, since the moving direction of the lens holding means is restricted to the optical axis direction by the guide means, when the lens position adjusting means is rotated, the screw on the outer surface of the lens holding means is rotated. The lens holding means moves in the optical axis direction with respect to the unit main body by the relative feed between the lens holding means and the screw portion of the lens holding means. The direction of this movement is determined by the rotation direction of the lens position adjusting means. When the focus position of the optical lens is adjusted in this way, the lens holding means and the optical lens move in the optical axis direction without rotating, so that the focus of the optical lens does not rotate but remains at a constant optical axis (straight line). ) Move up.

In the second laser incidence unit of the present invention, the bolt screwed to the lens holding means functions as a guide means when performing focus adjustment, and when the lens holding means or the optical lens is positioned and fixed. It functions as a lens holding means.

[0014]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a vertical cross-sectional view showing the structure of a laser injection unit according to an embodiment of the present invention, FIG. 2 is a side view of this unit seen from one end side, and FIG. 3 shows the structure of a support ring provided in this unit. FIG.

The laser incidence unit of this embodiment includes a unit body 10, an optical fiber attachment portion 14 for attaching one end portion of the optical fiber 12 to one end portion (left end portion in FIG. 1) of the unit body 10, and a unit. It is composed of a cylindrical lens holder 18 for holding a condenser lens 16 for condensing the laser light LB entering from the other end side (right end in FIG. 1) of the main body 10 on one end face of the optical fiber 12. Has been done. The laser light LB is, for example, emitted from a laser oscillator (not shown) and propagated in the air through an optical system (not shown).

A receptacle 20 for receiving one end of the optical fiber 12 is provided at the center of the optical fiber attachment portion 14. The tip ends of the X-direction position adjusting screw 22 and the coil spring 24 abut against the outer surface of the receptacle 20 against each other, and the Y-direction position adjusting screw 26 and the coil spring (not shown) respectively. The tips of these are also in contact with each other. The spring pressures of the coil spring 24 in the X direction and the coil spring in the Y direction are adjusted by the screws 25 and 27 screwed to the nuts 21 and 23 fixed to the side surface of the unit body 10. The positions of the receptacle 20 in the XY directions are adjusted by rotating the knobs (heads) of the X-direction position adjustment screws 22 and the Y-direction position adjustment screws 26, and by extension, the end faces of the optical fiber 12 in the XY directions. Can be aligned.

The condenser lens 16 is sandwiched and held between the projection 28 and the stopper ring 30 at an intermediate portion of the inner wall surface of the lens holding portion 18. The lens holding portion 18 is loosely fitted inside the cylindrical portion 10a extending from the intermediate portion to the other end portion of the unit body 10. On the side surface of the lens holder 18 closer to the center of the unit than the protrusion 28, a screw hole 18a is formed for screwing a bolt 34 described later. A thread 18b is formed on the outer wall surface of the lens holding portion 18 from the intermediate portion to the other end portion.

A guide groove 32 extending parallel to the optical axis is formed in the cylindrical portion 10 a of the unit body 10, and a bolt 34 is inserted into the screw hole 18 a of the lens holding portion 18 via the guide groove 32. It is screwed on. The guide groove 32 is composed of a narrow groove portion 32a which is loosely fitted to the shaft portion of the bolt 34 and a wide groove portion 32b which is loosely fitted to the head portion of the bolt 34. In this way, the bolt 34 screwed to the lens holding portion 18 can be moved only in the direction parallel to the optical axis by the guide groove 32 of the unit body 10. As a result, the lens holding portion 18 cannot move in the circumferential direction with respect to the unit body 10 and can move only in the optical axis direction.

The other end (right end) of the unit body 10 is provided with a step portion 36 and a protrusion portion 38 in the circumferential direction, and a groove portion in the circumferential direction defined by the step portion 36 and the protrusion portion 38. Alternatively, the support ring 40 is rotatably fitted in the recess. In order to enable this external fitting, the support ring 40 is divided into two as shown in FIG. A plurality of position adjusting rings 42, for example, four screws 44 are fixed to the support ring 40 from the outside so that the position adjusting ring 42 and the support ring 40 can rotate integrally. A screw thread 42a is cut on the inner peripheral surface of the position adjusting ring 42, and the screw thread 42a is screwed onto the screw thread 18a on the outer peripheral surface of the lens holding portion 18.

As described above, since the movement direction of the lens holding portion 18 is restricted to the optical axis direction by the bolt 34 and the guide groove 32, when the position adjusting ring 42 is rotated, the lens holding portion 18 is moved to the unit main body 10. It is designed to move with respect to the optical axis. The direction of movement of the lens holding portion 18 is determined by the rotation direction of the position adjusting ring 42. For example, when the position adjusting ring 42 is rotated clockwise, the lens holding portion 18 moves to one end side (right side) of the unit, and when the position adjusting ring 42 is rotated counterclockwise, the lens holding portion 18 moves to the other end side of the unit. It is supposed to move to the left side.

As described above, by rotating the position adjusting ring 42, the lens holding portion 18 can be moved in the optical axis direction (Z direction), and the focus of the condenser lens 16 can be adjusted to the end face of the optical fiber 12. In this focus adjustment, since the condenser lens 16 moves in the optical axis direction without rotating, the focus of the condenser lens 16 moves on a constant optical axis (straight line) without rotating. Therefore, even if the focus is adjusted after the centering of the optical fiber 14, the focus does not deviate from the center of the end face of the optical fiber 14.

When the focus is adjusted, the bolt 34 is loosened so that the lens holding portion 18 can slide in the optical axis direction with respect to the unit body 10. Then, when fixing the lens holding portion 18 and the condenser lens 16 at the focus adjusted position, the bolt 34 is tightened. Then, the lens holding portion 18 is pressed and fixed to the unit body 10 by the fastening force of the bolt 34, and cannot be moved. As described above, in the present laser incidence unit, since the lens holding portion 18 is pressed against and fixed to the unit body 10 in the direction perpendicular to the optical axis, the lens holding portion 18 and the condenser lens 16 are displaced. There is no inclination. Further, since the bolts 34 not only prevent the rotation of the lens holding portion 18 but also fix the lens holding portion 18, the number of parts is reduced and the structure is simplified.

In the above-described embodiment, the bolt 34 attached to the lens holding portion 18 and the guide groove 32 provided in the unit body 10 constitute the guiding means of the present invention. The guide means of the present invention can also be provided by providing one or a plurality of protrusions in the circumferential direction parallel to the optical axis on the outer side surface and providing a guide groove on the inner side surface of the unit body 10 so as to loosely fit these protrusions. It is possible to configure. Further, the optical fiber alignment adjusting means is not limited to the configuration including the resetter 20, the X-direction position adjusting screw 22, the Y-direction position adjusting screw 26, etc., and any conventionally known adjusting mechanism may be used. Is possible.

[0024]

[Effect of device]

 As described above, according to the first laser incidence unit of the present invention, the moving direction of the lens holding means is restricted to the optical axis direction by the guiding means, and the lens holding means is moved relative to the unit main body by the lens position adjusting means. Since the optical lens is moved only in the optical axis direction, the focus of the optical lens does not rotate, and the focus can be adjusted easily and accurately. Therefore, the focus does not deviate from the center of the end face of the optical fiber during the focus adjustment, and it becomes unnecessary to repeat the alignment of the optical fiber many times. Further, according to the second laser incidence unit of the present invention, since the bolt is used as both the guide means and the lens position fixing means, a simple unit construction with a small number of parts can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a structure of a laser incidence unit according to an embodiment of the present invention.

FIG. 2 is a side view showing an external structure of an optical fiber alignment adjusting section in the laser incidence unit of the embodiment.

FIG. 3 is a plan view showing the structure of a support ring in the laser incidence unit of the embodiment.

FIG. 4 is a vertical cross-sectional view showing the configuration of a conventional laser incidence unit.

[Explanation of symbols]

 10 unit main body 12 optical fiber 14 optical fiber mounting portion 16 condenser lens 18 lens holding portion 20 receptacle 22 X direction position adjusting screw 24 Y direction position adjusting screw 32 guide groove 34 bolt 40 support ring 42 position adjusting ring

Claims (2)

[Scope of utility model registration request] 1. An end face of the optical fiber, wherein one end of an optical fiber is detachably attached to one end of a unit body, and laser light entering from the other end side of the unit body is condensed by an optical lens. In the laser incidence unit adapted to be incident on, an optical fiber alignment adjusting means for adjusting the mounting position of the one end of the optical fiber in a direction perpendicular to the optical axis, and holding the optical lens on the inner surface, A cylindrical lens holding means that has a threaded portion on the outer side surface and is loosely fitted in the unit body; guide means that allows the lens holding means to move only in the optical axis direction with respect to the unit body; A ring-shaped lens position adjusting means that has a threaded portion that is screwed into a threaded portion on the outer side surface of the lens holding means, and that is rotatably attached to the unit main body. Laser incident unit. 2. The guide means is composed of a bolt guide groove formed on a side surface of the unit main body and a bolt screwed to the lens holding body via the bolt guide groove, and the bolt is The laser incidence unit according to claim 1, wherein the lens holding body is configured to be press-contacted and fixed to the unit main body by tightening.