JPH02201311A - Optical branching device - Google Patents

Abstract

PURPOSE:To shorten the switching time of channels and to branch pulses, one by one, on a time-division basis by providing mirrors which are arranged at equal intervals along an optical path of incidence and a mirror driving mechanism which rotates the mirrors while maintaining a constant tilt angle to incident light. CONSTITUTION:A time-division branching unit 11 is equipped with the four mirror members 15a - 15d which are arranged at equal intervals along the optical path 14 of the incident light 13 and the respective mirror members 15a - 15d are rotated at constant speed by the mirror driving mechanism 16 while holding the tilt angle at, for example, 45 deg. to the incident light 13. Therefore, even when the respective mirrors rotate at all times, the incidence angle of the incident light on the respective mirrors does not vary and the light never deviates from the optical axis. Consequently, the switching time of the channels can be shortened and a pulse laser which has a fast pulse rate can divide pulses, one by one, on a time-division basis.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable, for example, to time division branching of a laser beam output from one YAG laser oscillator into multiple optical paths to weld multiple locations. The present invention relates to an optical branching device used, and particularly to an optical branching device suitable for time-division branching of pulsed lasers.

[Prior Art] Generally, in the field of laser processing, one laser oscillator is used to process multiple workpieces or multiple locations on a single workpiece. , it is necessary to branch the incident light from the laser oscillator into multiple optical paths.

Conventionally, as a device for branching incident light from a laser oscillator into, for example, four optical paths, as shown in FIG.
four fiber input optical systems 3a, 3b, 3c,
3d, or as shown in FIG. 10, four mirrors 5a, 5b, 5c, 5d are used using four actuators 4a, 4b, 4c, 4d such as solenoids. A time-division branching type optical branching device is known in which the laser beam LB from the laser oscillator 1 is sequentially branched into four fiber input optical systems 3a, 3b, 3c, and 3d.

[Problems to be Solved by the Invention] By the way, in the conventional simultaneous branching type optical branching device, the laser beam LB is simultaneously transmitted to four fiber input optical systems 3a, 3.
b, 3c, and 3d, the power at each fiber input optical system 3a, 3b, 3c, and 3d belongs to the laser beam LB output from the laser oscillator l. There is no particular problem if the power of the LB is sufficient for processing purposes such as welding or drilling, but if it is not, there is a problem that it cannot be used.

On the other hand, the conventional time-division branching type optical branching device cannot perform simultaneous multi-point processing, but the power in each fiber input optical system 3a, 3b, 3c, and 3d is It has the advantage that it is the same as the output laser beam LB, and a small output laser oscillator 1 can be used.

However, in conventional time-division branching type optical branching devices, optical paths are switched using the reciprocating motion of mirrors, etc.
Each mirror cannot branch the laser beam LB to each fiber input optical system 3a, 3b, 3c, and 3d unless it stops at a regular position while crossing the incident optical path of the laser beam LB. It takes several 100 to switch. , , c, and the channel cannot be switched quickly. In particular, when using a pulse laser to time-division one pulse at a time and branching into each optical path, if the pulse rate is fast, branching becomes impossible, and actuators 4a, 4b, 4c, 4d and mirrors 5a, 5b
, 5c, and 5d are prone to failure.

The present invention was made in view of the current situation, and an object of the present invention is to provide an optical branching device that can significantly shorten the channel switching time and can time-division pulse by pulse even with a pulsed laser having a high pulse rate. do.

[Means for Solving the Problem] As a means for achieving the above object, the present invention provides a plurality of mirrors arranged at arbitrary intervals along the incident optical path of incident light;
A mirror drive mechanism that rotates each of these mirrors at a constant inclination angle with respect to the incident light and across the incident optical path at mutually different timings, and the incident light is divided into multiple optical paths in a time-sharing manner. It is characterized by being branched.

In the present invention, the mirror drive mechanism is provided with a detection means for detecting that a predetermined mirror is located on the incident optical path, and the incident light is intermittently outputted by a detection signal from the detection means. It is more preferable to

[Operation] In the optical branching device according to the present invention, incident light is branched into a plurality of optical paths in a time-sharing manner by a plurality of mirrors that cross an incident optical path at mutually different timings.

Incidentally, each of the mirrors is rotationally driven by a mirror drive mechanism while maintaining a constant inclination angle with respect to incident light. Therefore, even if each mirror is constantly rotating, the angle of incidence of the incident light on each mirror does not change, and the optical axis does not shift. Therefore, it is not necessary to stop the rotation of the mirror when switching the optical path, and it is possible to significantly shorten the channel switching time. As a result, even a pulsed laser with a fast pulse rate can be time-divided pulse by pulse.

At this time, the mirror drive mechanism is provided with a detection means for detecting that a predetermined mirror is located on the incident optical path,
By intermittently outputting the incident light using the detection signal from this detection means, it becomes possible to completely synchronize the intermittent output of the incident light and channel switching, and each pulse of the pulsed laser Time division branching can be performed more safely.

[Example] A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an optical branching device according to the present invention. In the figure, reference numeral 11 is a time-division branching unit, and this time-division branching unit 11, as shown in FIG.
Incident light 13 from a laser head 12 that oscillates a laser is time-divisionally branched into four fiber input optical systems 3a, 3b, 3c, and 3d.

The time-division branching unit 11 includes four mirror members 15a arranged at predetermined intervals along the incident optical path 14 of the incident light 13, as shown in FIG.

These mirror members 15a, 15b, 15c, and 15d are rotated at a constant speed by a mirror drive mechanism 16 while maintaining an inclination angle of, for example, 45 degrees with respect to the incident light 13. It is now possible to do so.

Each of the mirror members 15a, 15b, 15c.

15d is a rotating shaft 17a, as shown in FIG.

A hub portion 18a, a ring-shaped rim portion 18b, and a hub portion 18a and a rim portion 1 that are pivotally attached to 17b, 17c, and 17d.
8b at 90 degree intervals.
It is equipped with a rotary plate 18 consisting of 8c, and this rotary plate 18
Between the adjacent arm parts 18c, there are three incident light passing windows 19, and the incident light 13 is passed through each of the fiber input optical systems 3a.

One mirror 20a for reflecting to 3b, 3c, 3d
, 20b, 20c, and 20d are provided, respectively. And each mirror member 15a.

15b, 15c, 15d are the respective mirrors 20a, 20
b, 20c, 20d are set so that they are shifted by 90 degrees, so each mirror 20a, 20b, 20c
, 20d are each mirror member 15a, 15b, 15c, 1
5d are rotated at a constant speed by the mirror drive mechanism 16, they cross the incident optical path 14 at mutually different timings.

Each of these mirrors 20a, 20b, 20c.

20d crosses the incident optical path 14, as shown in FIGS. 1 and 3, each mirror member 15a, 15b
, 15c, , 15d, and sensors 21a, 21b, 21c, 21d, such as proximity switches, and each mirror member 15a.

15b, 15c, and 15d are detected by detection pieces 22 provided on the outer periphery of the rim portion 18b, respectively, and the sensors 21a, 21b.

As shown in FIG. 2, the detection signals from 21c and 21d are inputted to the laser power supply 24 as a trigger pulse through the channel changeover switch 23, and the laser head 12 generates a pulsed laser beam by the manual input of the trigger pulse. is output as incident light 13. This will be detailed later.

On the other hand, the mirror drive mechanism 16 includes a motor 25 that rotates at a constant speed, as shown in FIG.
Belt pulleys 27a, 27b, 2 attached to 17c, 17d
7c, 27d, endless timing belts 28a, 2
8b.

Belt pulleys 29a and 2 connected via 28c and 28d
9b, 29c, and 29d are each pivoted. And each mirror member 15a.

15b, 15c, and 15d are driven to rotate at a constant speed by the rotation of the motor 25.

In addition, in FIG. 1 and FIG. 2, reference numerals 30a and 30
b, 30c, and 30d are each of the fiber input optical systems 3a.
, 3b, 3c, and 3d, respectively.

Next, the operation of this embodiment will be explained.

When the motor 25 is started, its output shaft 26 rotates at a constant speed, and its rotational force is applied to the belt pulley 29a.

29b, 29c, 29d, 27a, 27b.

27c, 27d and timing belt 28a.

Each rotating shaft 17a, 17 via 28b, 28c, 28d
b, 17c, 17d, and each Mira one member 15a,
15b, 15c, and 15d are rotated at a constant speed.

By the way, each Mira one member 15a, 15b.

15c and 15d are mirrors 20a that rotate while maintaining an inclination angle of 45 degrees with respect to the incident light 13;

Since the mirrors 20b, 20c, and 20d are set to be offset by 90 degrees, each mirror 20a.

20b, 20c, and 20d cross the incident optical path 14 at different timings while maintaining a constant inclination angle with respect to the incident light 13. And each mirror 20a
, 20b, 20c, and 20d cross the incident optical path 14 depending on the timing of each of the corresponding sensors 21a, 21b,
They are detected at 21c and 21d, respectively.

These detection signals are input to the channel changeover switch 23 as shown in FIG. 2, and only a selected one of them is input to the laser power source 24 as a trigger pulse. The laser head 12 outputs pulsed laser light as incident light 13 upon input of this trigger pulse.

For example, when the CHI sensor 21a (corresponding to the CHI sensor 21a) is selected by the channel changeover switch 23, the laser head 12
The incident light 13 is outputted from the fiber input optical system 3a, and therefore, the incident light 13 is reflected by the mirror 20a and branched into the fiber input optical system 3a. The same applies to CH2 (corresponding to sensor 21b), CH3 (corresponding to sensor 21c), and CH4 (corresponding to sensor 21d). Also, by using the channel changeover switch 23, all channels CH1, CH2, C
When selecting H3, CH4, each sensor 21a, 2
Detection signals from 1b, 21c, and 21d are sequentially input as trigger pulses to the laser power supply 24, and the laser head 12
From there, pulsed laser light is output as incident light 13 in accordance with this. FIG. 4 shows this state. In this case, the incident light 13 is transmitted one pulse at a time to each fiber input optical system 3.
It is time-divisionally branched into a, 3b, 3c, and 3d.

In that case, the pulse rate is
, 15b, 15c.

It is determined at a rotation speed of 15d. In addition, in Figure 4,
Symbol R indicates each mirror member 15a, 15b.

The time for one rotation of 15c and 15d is shown.

Thus, each mirror 20a, 20b, 20c.

20d is rotated while maintaining a constant inclination angle with respect to the incident light 13, so even if it is constantly rotating, each mirror 20d
The angle of incidence of the incident light 13 on a, 20b, 20c, and 20d does not change, so the optical axis does not shift. Therefore, the channel switching time can be significantly shortened, and the pulsed laser has a high pulse rate. Also, time-division branching can be performed pulse by pulse. Since the pulse rate is determined by the rotation speed of the mirrors 20a, 20b, 20c, and 20d, the pulse laser and channel switching can be completely synchronized.

FIG. 5 shows a second embodiment of the present invention.
In place of the mirror member 15d in the embodiment, a fixed mirror 31 is installed on the incident optical path 14 of the incident light 13, and a rotary plate 18 without the mirror 20d is provided at a position away from the incident optical path 14, and in the vicinity thereof. A sensor 20d is installed. Note that the other points have the same configuration as the first embodiment.

Even with this configuration, the same effects as in the first embodiment can be obtained.

FIG. 6 shows a third embodiment of the present invention.
The fixed mirror 31 in the embodiment is omitted, and the fiber input optical system 3d is arranged on the input optical path 14 of the incident light 13.

Note that the other points have the same configuration as the second embodiment.

With this configuration, similar effects can be expected with a smaller number of parts.

FIGS. 7 and 8 show a fourth embodiment of the present invention, in which a single sensor can detect the position of each mirror and switch channels.

That is, as shown in FIG. 7, the output shaft 26 of the motor 25 is provided with a predetermined number of mirror position detection plates s, s2 .・
..., s, .

S2. ..., S, ..., Sn can be slid.

Each of the mirror position detection plates S, , S, . . . S, ,
, S, are each provided with a detection piece 22 at the position of the channel to be selected, as shown in FIG. 8. For example, when the sensor 41 is associated with the mirror position detection plate S, Each mirror 20a, 20b, 20c, 20d (
The sensor 41 sequentially detects the timing at which the light (see FIG. 3) crosses the incident optical path 14, and the sensor 41 outputs a detection signal;
By inputting the trigger pulse to the laser power supply 24, pulsed laser light similar to that shown in FIG. 4 is outputted from the laser head 12 as the incident light 13. Note that the other points have the same configuration as the first embodiment.

With this configuration, the mirror position detection and channel switching can be performed with one sensor 41, and the structure can be simplified.

In addition, in each of the above embodiments, each mirror member 15a,
The case where the inclination angles of the incident light 13 of 15b, 15c, and 14d are all the same has been described;
If it rotates while maintaining a constant inclination angle with respect to each mirror member 15a.

It is not necessary that the inclination angles of 15b, 15c, and 15d have the same value.

Furthermore, in each of the above embodiments, the case where the channels are branched into four channels has been described, but there is no limit to the number of branches as long as there are two or more channels. It can also be applied to time-division branching of light other than lasers.

Further, in each of the above embodiments, although the output form of the pulsed laser light outputted from the laser head 12 as the incident light 13 was not particularly explained, the present invention can be similarly applied to pulses of any waveform. Further, the present invention can also be applied when the incident light 13 is a continuous output. However, if the continuous output incident light 13 is a laser beam, the one-rotation plate 18
Since the arm part 18c (see FIG. 3) of the time division branching unit 11 may be damaged by the laser beam,
For example, on the right side of the Mirai member 15a in FIG.
A shutter may be provided to block the incident light 13 at the timing when the arm portion 18c crosses the incident optical path 14, or the rotating plate 18 may be replaced with mirrors 20a, 20b, 20c, 20d.
It is necessary to create a structure that supports only the back side of the

[Effects of the Invention] As explained above, the present invention includes a plurality of mirrors arranged at arbitrary intervals along the incident optical path of incident light, and a method of rotating each of these mirrors while maintaining a constant inclination angle with respect to the incident light. Since each of the mirrors is driven to cross the incident optical path at different timings, the channel switching time can be significantly shortened, and the pulsed laser has a high pulse rate. However, time-division branching can be performed pulse by pulse.

At this time, a detection means is provided for detecting that a predetermined mirror is located on the incident optical path using a mirror drive mechanism, and the incident light is intermittently outputted by a detection signal from this detection means. As a result, the intermittent output of the incident light and the channel switching can be completely synchronized, and the time-division branching of each pulse of the pulsed laser can be performed more stably.

[Brief explanation of the drawing]

FIG. 1 is a detailed view of the main parts of an optical branching device according to a first embodiment of the present invention, FIG. 2 is a similar overall configuration diagram, FIG. 3 is an explanatory diagram showing the configuration of a mirror member, and FIG. 4 5 is a time chart showing the relationship between the detection signal of each sensor, trigger pulse, and incident light, FIG. 5 is a diagram corresponding to FIG. 1 showing the second embodiment of the present invention, and FIG. 6 is a third embodiment of the present invention. FIG. 7 is a diagram corresponding to FIG. 1 showing the fourth embodiment of the present invention, FIG.
An explanatory diagram showing the configuration of each mirror position detection plate in the figure,
FIG. 9 is a block diagram showing a conventional optical branching device of a simultaneous branching method, and FIG. 1O is a block diagram showing a conventional optical branching device of a time division branching method. 3a, 3b, 3c, 3d + fiber input optical system ll: time division branching unit 13: incident light 14: input optical path 15a, 15b, 15c, 15d: mirror member l6: mirror drive mechanism 20a, 20b, 20c, 20d: mirror 21a, 21
b, 21c, 21d: Sensor 22: Detection piece 23/Channel selection switch

Claims (1)

[Scope of Claims] 1) A light branching device that branches incident light focused to an arbitrary diameter into a plurality of optical paths, including a plurality of mirrors arranged at arbitrary intervals along the incident optical path of the incident light; An optical branching device comprising: a mirror drive mechanism that maintains a constant inclination angle with respect to incident light and rotates the mirror so as to cross an incident optical path at mutually different timings. 2) The mirror drive mechanism includes a detection means for detecting that a predetermined mirror is located on the incident light path, and the incident light is
2. The optical branching device according to claim 1, wherein the optical branching device is intermittently outputted by a detection signal from the detection means.