JPH0890272A - Laser beam machine - Google Patents

Abstract

PURPOSE: To facilitate the adjustment of incidence of an optical fiber by reducing a loss of guide beam and also to miniaturize the subject device. CONSTITUTION: A guide beam LB emitted from an alignment laser 16 is made incident on the front side of a mirror 24 through a mirror 22, and two split guide beams LB1, LB2 which are parallel to each other are emitted from the outer reflecting surface 24a and the inner reflecting surface 24b of the mirror 24 towards an incident unit 14. These split guide beams LB1, LB2 are made incident on the rear side of a mirror 20, transmitted straight through it, and made incident on the one end face 12a of an optical fiber 12 through a condenser lens 30, individually forming a spot. A guide beam spot that is reflected on the one end face 12a of the optical fiber 12 is observed by means of an optical fiberscope 26 through the mirrors 20, 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device in which laser light from a laser oscillator is made incident on one end face of an optical fiber.

[0002]

2. Description of the Related Art In a laser device for processing such as a YAG laser, in order to perform laser processing at a place distant from the main body of the device, an incident unit inside the main body of the device and an emitting unit at a remote (processing place) are formed by an optical fiber. As a result, the laser light generated in the main body of the apparatus is transmitted from the incident unit to the emission unit through the optical fiber, and the laser light is emitted toward the workpiece on the emission unit side. In this case, in the entrance unit on the apparatus main body side, the laser light must be properly incident on one end face of the optical fiber (that is, focused on the center of the end face). If the laser light is not accurately incident on the optical fiber, the laser output will be largely lost, or the end face of the optical fiber will be burned. Therefore, at the time of assembling or setting the apparatus, the position of the condenser lens in the incident unit is adjusted (focused) in the optical axis direction (Z direction), and the mounting position of the optical fiber is set in a direction perpendicular to the optical axis direction (XY direction). Direction) to adjust (align the optical axis).

In this type of laser device, the main laser light is generally invisible light (for example, YAG laser light is infrared light).
Therefore, as a guide light for performing the optical fiber incidence adjustment (focusing and optical axis adjustment adjustment) as described above, a laser that outputs visible light having a strong straight traveling property, for example, red laser light in a continuous oscillation (CW) mode. A so-called alignment laser is provided.

Conventionally, an alignment laser is optically arranged at a rear position with respect to a processing laser oscillator which generates a laser beam for laser processing, and a visible guide light emitted from the alignment laser is processed by the processing laser oscillator. It was put from the back side into the same optical path as the laser beam for processing, guided to an entrance unit by a mirror, and made to enter one end face of the optical fiber through a condenser lens. When adjusting the optical fiber incidence, the operator observes the one end face of the optical fiber with an optical fiber scope, and the spot of the guide light is focused on the center of the end face of the optical fiber. The position and the mounting position of the optical fiber were adjusted.

[0005]

As described above, in the conventional laser device, the guide light emitted from the alignment laser passes through the processing laser oscillator and then enters the end face of the optical fiber. Optical resonator in processing laser oscillator (total reflection mirror and output mirror)
Is coated with a reflection coating for the wavelength of the processing laser light but not for the wavelength of visible light, the guide light can pass through the optical resonator. However, the guide light still suffers some loss when passing through the optical resonator, and also suffers considerable loss (attenuation) when passing through the laser medium. For this reason, the light intensity of the guide light incident on the incident unit becomes low, and as a result, the spot of the guide light reflected on the end face of the optical fiber is not clear, and it is difficult to know the presence or the position of the spot.

Further, in the conventional laser device, since the alignment laser or the mirror is arranged behind the processing laser oscillator which occupies the largest space in the device, the size of the device becomes large in the longitudinal direction, and the size can be reduced. There is also the problem of difficulty.

The present invention has been made in view of the above problems, and provides a laser device that reduces the loss of guide light, facilitates the adjustment of optical fiber incidence, and realizes downsizing of the device. The purpose is to

[0008]

In order to achieve the above object, the first laser device of the present invention is such that one end of the unit body holds one end of the optical fiber, and the other end of the unit body holds. An input unit that collects the laser light entering from the light entrance port of the optical lens by an optical lens and makes it enter the one end face of the optical fiber; a main laser light generating unit that generates the main laser light; and a visible guide light. The guide light generating means for generating and the first and second reflecting surfaces which are parallel to each other are provided, and the guide light from the guide light generating means is caused to enter the first reflecting surface, and the first reflecting surface. Part of the guide light is reflected in a predetermined direction and the rest is transmitted,
A first mirror of a split reflection type that reflects the transmitted light from the reflecting surface of the second reflecting surface in the predetermined direction by the second reflecting surface;
Is disposed between the mirror and the main laser light generating means and the incident unit, and the two split guide lights from the first mirror are incident on the back side surface and transmitted to the light incident port side of the incident unit. At the same time, the main laser light from the main laser light generating means is made incident on the front side surface and reflected to the light entrance side of the incident unit coaxially with either one of the two reflected lights from the first mirror. It is configured to include a second mirror.

A second laser device according to the present invention is the first laser device according to the first laser device, wherein the second laser device is arranged between the main laser light generating means and the second mirror. Visible light that is incident on the front side surface of the main laser light and reflected toward the second mirror side, and is incident on the front side surface from one end surface of the optical fiber through the optical lens and the second mirror. Is provided with a third mirror for transmitting one end surface of the optical fiber to the scope side for visually observing.

[0010]

In the laser device of the present invention, the guide light from the guide light generating means is incident on the first mirror, so that the two divided guide lights that are parallel to each other from the outer reflecting surface and the inner reflecting surface of the first mirror. Comes out in a predetermined direction. These two split guide lights pass through the second mirror, enter the entrance unit, and enter the end face of the optical fiber through the optical lens in the unit. As a result, spots of the split guide light are projected on the end face of the optical fiber. These guide light spots are reflected at a position apart when the end face of the optical fiber is displaced from the focus of the optical lens, and overlap when the end face of the optical fiber is located at the focus of the optical lens. Also,
The spot diameter of the guide light spot changes depending on whether the position of the end face of the optical fiber is near or far from the focal point of the optical lens.
While observing the end face of the optical fiber with a scope, the worker adjusts the position of the optical lens and the mounting position of the end face of the optical fiber so that the two guide light spots substantially overlap with each other at the center of the end face of the optical fiber. Good.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows the structure of the main part of a laser device according to an embodiment of the present invention.

This laser device includes a YAG laser oscillator 10 for generating a YAG laser beam LA for processing, an incident unit 14 for causing the YAG laser beam LA to enter one end face 12a of an optical fiber 12, and a visibility guide. An alignment laser 16 for generating the light LB, a plurality of mirrors 18 to 24 for guiding the YAG laser light LA from the YAG laser oscillator 10 or the guide light LB from the alignment laser 16 to the incident unit 14, and one of the optical fibers 12 And an optical fiber scope 26 for visually observing the end face (laser incident face) 12a.

Inside the YAG laser oscillator 10, the YA
The G rod (laser medium) and the excitation lamp are arranged in parallel in a predetermined positional relationship, and a total reflection mirror and an output mirror that form an optical resonator are arranged on both sides of the YAG rod on the optical axis. When the excitation lamp is turned on in the oscillator 10, the YAG rod receives the light energy and laser-oscillates, and light is emitted from both end faces thereof. Of the emitted light, the light having the resonance frequency is the total reflection mirror and the output mirror. And a part of it is output as laser light LA for laser processing from the output mirror.

The alignment laser 16 is, for example, He.
A Ne laser, a semiconductor laser, or a light emitting diode is used to generate, for example, red light as the guide light LB.

The incident unit 14 opposes a fiber attachment portion 28 that detachably attaches and holds one end portion of the optical fiber 12 on one end side of the unit body, and one end surface of the optical fiber 12 held by the fiber attachment portion 28. And a condenser lens 30 movably arranged in the optical axis direction at a position where the light enters from the light entrance 14a on the other end side of the unit main body is condensed by the condenser lens 30 and Fiber 1
2 has a structure in which the light is incident on one end surface (laser incidence surface) 12a of the second laser beam 2. The specific configuration of the incident unit 14 will be described later with reference to FIGS. 2 and 3.

The optical fiber scope 26 is a short-distance type scope or an optical finder, and has a moving lens 3 inside.
By moving the lenses 2 and 34 in the optical axis direction, the light entering the light entrance 26a is focused on the human eye 36 that is in contact with the eyepiece of the scope to form an image. Optical fiber scope 2 in this laser device
Reference numeral 6 denotes mirrors 18 and 20 and a condenser lens 30 described later.
Through one end surface (laser incidence surface) 12 of the optical fiber 12
It is arranged so that a can be observed.

The mirrors 18 to 24 are arranged at the positions and angles shown in the drawing. That is, the mirror 2
0 is arranged so that the front reflecting surface 20a thereof faces the light entrance 14a of the entrance unit 14 at an angle of 45 °, and the condenser lens 30
Is placed on the optical axis of. The mirror 18 is arranged at a position where the front reflecting surface 18a is opposed to the exit of the YAG laser oscillator 10 at an angle of 45 ° and reflects the YAG laser light LA from the YAG laser oscillator 10 toward the mirror 20. The mirror 24 has its front reflecting surface 24a inclined to the light incident port 14a of the incident unit 14 at an angle of 45 ° and is arranged on the optical axis of the condenser lens 30 behind the mirror 20 when viewed from the incident unit 14. . The mirror 22 is arranged at a position where the reflection surface 22a on the front side is opposed to the emission port of the alignment laser 16 at an angle of 45 ° and the YAG laser beam LB from the alignment laser 16 is reflected toward the mirror 24.

When any light (either laser light or visible light) is incident on the front reflection surface 20a, the mirror 20 reflects the light at a reflection angle corresponding to the incident angle, and makes it visible on the rear surface 20b. It is configured to transmit light straight through. The mirror 18 reflects the YAG laser light at a reflection angle corresponding to the incident angle when the YAG laser light is incident on the front reflection surface 18a, but transmits the visible light straight when the visible light is incident. Is configured. The mirror 22 is configured to reflect visible light at a reflection angle corresponding to the incident angle when the visible light is incident on the front reflection surface 22a.

The mirror 24 has a front side outer reflection surface 24a (first reflection surface) and a back side inner reflection surface 2 which are parallel to each other.
4b (second reflection surface) is a partial reflection surface and a total reflection surface, respectively, and when visible light is incident from the front side, part of the visible light is reflected by the outer reflection surface 24a at a reflection angle corresponding to the incident angle. At the same time, the rest (visible light transmitted through the outer reflection surface 24a) is entirely reflected by the inner reflection surface 24b at a reflection angle corresponding to the incident angle.
The reflectance / transmittance of the outer reflecting surface 24a may be appropriate, and may be selected to be 50% and 50%, for example. As described above, the mirror 24 is of a split reflection type in which, when one visible ray enters from the front side, two parallel split visible rays are emitted from the outer reflecting surface 24a and the inner reflecting surface 24b.

In the laser device of this embodiment constructed as described above, when adjusting the optical fiber incidence, YA
The laser oscillation operation of the G laser oscillator is stopped and only the alignment laser 16 is caused to emit light. Alignment laser 1
The guide light LB emitted from 6 travels straight to the mirror 22.
Is incident on the front-side reflecting surface 22a, is reflected there, the optical path is bent at a right angle, and enters the mirror 24 from the front side.

In this mirror 24, part of the guide light LB is reflected by the outer reflection surface 24a to bend the optical path at a right angle, and the rest (visible light transmitted through the outer reflection surface 24a) is entirely reflected on the inner reflection surface 24b. The light path is reflected at a right angle. As a result, two split guide lights LB1 and LB parallel to each other from the mirror 24 toward the incident unit 14 are obtained.
2 comes out. Of the split guide lights LB1 and LB2, the split guide light LB2 from the inner reflection surface 24b travels on the optical axis of the condenser lens 30 of the incident unit 14,
The position of the mirror 24 is adjusted.

The two parallel guide light beams LB1 and LB2 from the mirror 24 are incident on the mirror 20 from the back side and are transmitted straight therethrough, and pass through the light incident port 14a of the incident unit 30 to form a condenser lens. It is incident on each of 30. Of the two split guide lights LB1 and LB2 that have entered, the guide light LB2 on the optical axis goes straight as it is, but the guide light LB1 which is offset by a predetermined distance from the optical axis bends the optical path toward the optical axis by the lens 30. Then, go straight toward the focal point of the lens 30.

Thus, the one end face 12a of the optical fiber 12 is
When both guide lights LB1 and LB2 are incident on, the respective spots are reflected there. These guide light spots are
When the one end surfaces 12a of the optical fibers 12 are displaced from the focal point of the condenser lens 30, they appear at positions distant from each other, and when the one end surfaces 12a of the optical fiber 12 are located at the focal point of the condenser lens 30, they overlap each other.

Thus, the one end face 12a of the optical fiber 12 is
The guide light spot reflected in the image is visually observed by the optical fiber scope 26. That is, the visible light LC representing the image of the one end face 12a of the optical fiber 12 enters the mirror 20 from the front side and is reflected at a right angle by the reflecting surface 20a there, and then enters the mirror 18 from the front side to straighten the part. The light is transmitted and enters the light incident port 26a of the optical fiber scope 26, and the moving lenses 32 and 34 in the optical fiber scope 26 are transmitted.
An image is formed on the eyes 36 of the worker through the image. Prior to the adjustment of the optical fiber incidence, visible light is introduced from the other end surface (not shown) of the optical fiber 12 and the one end surface 12a of the optical fiber 12 is introduced.
The optical fiber scope 26 can be focused by emitting light.

In the laser device of this embodiment, the optical fiber 1
Visible light LC from one end surface (laser incident surface) 12a of 2 is guided to the optical fiber scope 26 via the mirrors 20 and 18 without passing through the split reflection mirror 24, so that there is little loss and clear guide light. You can give an image of the spot.

The worker works on one end face 12a of the optical fiber 12.
The position on the optical axis (Z direction) of the condensing lens 30 and the mounting position of the optical fiber end face 12a in the XY directions may be adjusted so that the two guide light spots overlap each other in the center portion of the. However, due to the chromatic aberration of the condenser lens 30, the focus of the visible guide light LB is slightly closer to the lens 30 side than the focus of the YAG laser light LA, and the end face of the optical fiber is YA.
Since the end face of the G laser beam may be burned out by the energy of the laser when it is located at the focal point, the focusing is usually performed so that the guide light spot is slightly defocused.

After the YAG laser oscillator 10 is oscillated after the optical fiber incidence adjustment as described above, YA
YAG laser light LA emitted from the G laser oscillator 10
Is incident on the mirror 18 from the front side and the reflecting surface 18a there.
On the optical axis of the condensing lens 30 after being reflected by the mirror 20 to bend the optical path at a right angle to the mirror 20 side, then incident on the mirror 20 from the front side and reflected by the reflecting surface 20a there to bend the optical path to the incident unit 14 side. And goes straight to the center of the one end face 12a of the optical fiber 12 with a slight defocus.

The other end of the optical fiber 12 is remotely connected to, for example, an emission unit (not shown) at a processing site. The YAG laser light LA that has entered the one end face 12a of the optical fiber 12 by the incident unit 14 is transmitted through the optical fiber 12 to the emission unit, where it is focused and irradiated toward the workpiece.

2 and 3 show a structural example of the incident unit 14. 2 is a vertical cross-sectional view of the unit 14, and FIG. 3 is a side view of the unit 14 seen from one end side.

This incident unit is composed of a unit body 40.
And one end of the unit body 40 (the left end in FIG. 2)
The optical fiber attachment portion 28 for detachably attaching one end portion of the optical fiber 12 to the optical fiber 12 and the light beam L entering from the light entrance port 14a on the other end side (the right end portion in FIG. 2) of the unit body 40 of the optical fiber 12. It is composed of a cylindrical lens holding portion 42 that holds a condenser lens 30 for condensing on the one end face 12a. In this embodiment, the light beam L is the YAG laser light LA from the YAG laser oscillator 10 and / or the guide light LB from the alignment laser 16.

A receptacle 44 for receiving one end of the optical fiber 12 is provided at the center of the optical fiber mounting portion 42. The outer surface of this receptacle 44 has an X
The respective tip portions of the position adjusting screw 46 and the coil spring 48 in the directional direction abut against each other, and the respective tip portions of the position adjusting screw 50 in the Y direction and the coil spring (not shown) also abut against each other. There is. The spring pressures of the coil spring 48 in the X direction and the coil spring in the Y direction are adjusted by the screws 56 and 58 screwed to the nuts 52 and 54 fixed to the side surface of the unit body 40. By rotating the respective knobs (heads) of the X-direction position adjusting screw 46 and the Y-direction position adjusting screw 50, the position of the receptacle 44 in the XY direction is adjusted, and by extension, the XY position.
The end face 12a of the optical fiber 12 in the direction can be aligned (centering).

The condenser lens 30 is sandwiched and held between the projection 60 and the stopper ring 62 at the intermediate portion of the inner wall surface of the lens holding portion 42. The lens holding portion 42 is a cylindrical portion 40 that extends from the middle portion to the other end of the unit body 40.
It is loosely fitted inside a. Protrusion 6 of lens holding part 42
On the side surface closer to the center of the unit than 0, a bolt 6 to be described later
A screw hole 42a for screwing 4 is provided. A thread 42b is formed on the outer wall surface of the lens holding portion 42 from the middle portion to the other end.

A guide groove 66 extending parallel to the optical axis is formed in the cylindrical portion 40a of the unit body 40, and a bolt 64 is screwed into the screw hole 42a of the lens holding portion 42 through the guide groove 66. I'm wearing it. Guide groove 66 is bolt 64
The groove portion 66a has a narrow groove width that is loosely fitted to the shaft portion of and the head portion of the bolt 64 is a groove portion 66b that has a wide groove width. In this way, the bolt 6 screwed to the lens holding portion 42
The guide groove 66 of the unit body 40 allows the unit 4 to move only in a direction parallel to the optical axis. As a result, the lens holding portion 42 cannot move in the circumferential direction with respect to the unit body 40, and can move only in the optical axis direction.

At the other end (right end) of the unit body 40, a step 68 and a protrusion 70 are provided in the circumferential direction, and a groove in the circumferential direction defined by the step 68 and the protrusion 70 is formed. Alternatively, the support ring 72 is rotatably fitted in the recess. In order to enable this external fitting, the support ring 70 is divided into two. The position adjusting ring 74 is fixed to the support ring 70 from the outside by a plurality of screws 76, for example, four screws 76, so that the position adjusting ring 74 and the support ring 76 can rotate integrally. A screw thread 74a is formed on the inner peripheral surface of the position adjusting ring 74, and the screw thread 74a is screwed onto the screw thread 42b on the outer peripheral surface of the lens holding portion 42.

As described above, since the moving direction of the lens holding portion 42 is restricted to the optical axis direction by the bolt 64 and the guide groove 66, when the position adjusting ring 74 is rotated, the lens holding portion 42 is moved to the unit main body 40. It is designed to move with respect to the optical axis. The direction of movement of the lens holder 42 is determined by the rotation direction of the position adjusting ring 74. For example, when the position adjusting ring 74 is rotated clockwise, the lens holding part 42 moves to one end side (right side) of the unit, and when the position adjusting ring 74 is rotated counterclockwise, the lens holding part 42 moves to the other end side of the unit (right side). It is designed to move to the left side).

As described above, by rotating the position adjusting ring 74, the lens holder 42 can be moved in the optical axis direction (Z direction) and the focus of the condenser lens 30 can be adjusted near the end face 12a of the optical fiber 12. it can. In this focus adjustment, since the condenser lens 30 moves in the optical axis direction without rotating, the focus of the condenser lens 30 moves on a constant optical axis (straight line) without rotating. Therefore, even if the focus is adjusted after the centering of the optical fiber 12, the focus does not deviate from the center of the end face of the optical fiber 12.

As described above, in the laser device of this embodiment, the guide light L emitted from the alignment laser 16 is used.
B does not pass through the YAG laser oscillator 10,
Injection unit 1 via three mirrors 22, 24, 20
It is designed to enter 4. Mirrors 22, 24, 2
Since the attenuation or loss of the light intensity due to the reflection or transmission at 0 is small, the guide light LB is incident on the incident unit 14 with sufficient light intensity and forms a bright spot on the end face 12a of the optical fiber 12. In addition, the optical fiber scope 26
Is the end face 12a of the optical fiber 12 via the mirror 20 and the condenser lens 30 without passing through the split reflection type mirror 24.
You can watch.

Therefore, the operator can clearly see the contour and position of the guide light spot reflected on the end face 12a of the optical fiber 12, and the position adjustment (focusing) of the condenser lens in the incident unit 14 and the optical fiber. The mounting position adjustment (optical axis alignment) can be easily performed in a short time.

Further, in the laser device of this embodiment, the YAG
Since it is not necessary to dispose the alignment laser 16 or an optical component such as a mirror behind the laser oscillator 10, the dimension of the unit in the longitudinal direction is accordingly shorter than that of the conventional device, and the device can be miniaturized.

The mirrors 18 to 24 in the above embodiment.
The arrangement configuration and the number of installed sheets are examples, and various modifications can be made according to the arrangement position of the YAG laser oscillator 10 or the alignment laser 16. For example, as shown in FIG. 4, the YAG laser oscillator 10 for the mirror 20 is used.
When the arrangement position of the optical fiber scope 26 is opposite to that of the above embodiment, the split guide light LB1 from the outer reflecting surface 24a of the two split guide lights LB1 and LB2 from the mirror 24 is reflected by the mirror 20. At the end of the light beam becomes coaxial with the YAG laser light LA or the visible light of the optical fiber scope system, and the split guide light LB2 from the inner reflecting surface 24b becomes YA.
It suffices to pass the optical path that does not interfere with the G laser light LA or the visible light of the optical fiber scope system.

Further, the processing laser oscillator in the laser device of the present invention is not limited to the YAG laser oscillator, but may be a carbon dioxide laser oscillator or the like. Further, the present invention can be applied to various laser devices other than the processing laser device.

[0043]

As described above, according to the laser device of the present invention, the guide light from the guide light generating means is guided to the incidence unit without passing through the main laser light generating means and is guided to one end face of the optical fiber. Since the light is made incident, the guide light loss is small, and a clear guide light spot is formed on the end face of the optical fiber. Further, by guiding visible light from one end surface of the optical fiber or the laser incident surface to the optical fiber scope without passing through the split reflection type mirror, the guide light spot on the end surface of the optical fiber can be more clearly observed. Thereby, the optical fiber incidence adjustment can be easily performed. Further, since it is not necessary to dispose an optical component such as a mirror for introducing the guide light behind the main laser light generating means, it is possible to realize the miniaturization and space saving of the device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a laser device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a configuration example of an incidence unit in the laser apparatus of the embodiment.

FIG. 3 is a side view showing a configuration example of an incidence unit in the laser apparatus of the embodiment.

FIG. 4 is a block diagram showing a modification of the laser device according to the embodiment.

[Explanation of symbols]

 10 YAG Laser Oscillator 12 Optical Fiber 12a One End Surface of Optical Fiber 14 Incident Unit 18, 20, 22 Mirror 24 Split Reflective Mirror 28 Optical Fiber Mounting Part 30 Condensing Lens

Claims (2)

[Claims] 1. An incident unit for attaching one end of an optical fiber, condensing light entering from a predetermined light incident port by an optical lens and making the light incident on one end face of the optical fiber, and generating a main laser beam. A main laser light generating means, a guide light generating means for generating a visible guide light, and first and second reflecting surfaces parallel to each other, and the guide light from the guide light generating means is the first Of the guide light is reflected by the first reflection surface in a predetermined direction and the rest is transmitted, and the transmitted light from the first reflection surface is reflected by the second reflection surface. A split reflection type first mirror for reflecting in a predetermined direction, and two split guides from the first mirror, which are arranged between the first mirror and the main laser light generating means and the incident unit. Let the light enter the back side And transmits the main laser light from the main laser light generating means to the front side surface, and substantially one of the two reflected lights from the first mirror. A second mirror that reflects the light to the light entrance side of the entrance unit along the same optical path. 2. The second mirror side is arranged between the main laser light generating means and the second mirror so that the main laser light from the main laser light generating means is incident on the front side surface. A scope side for reflecting visible light from one end face of the optical fiber through the optical lens and the second mirror and visually observing the one end face of the optical fiber. 2. A third mirror for transmitting light to the second mirror is further provided.
The laser device according to.