JPH0640176B2 - Optical branching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applicable, for example, to a case where a laser beam output from one YAG laser oscillator is time-divisionally divided into a plurality of optical paths to weld a plurality of points. The present invention relates to an optical branching device used, and particularly to an optical branching device suitable for time division branching of a pulse laser.

[Prior Art] Generally, in the laser processing field, one laser oscillator is used to process a plurality of works or a plurality of positions of a single work. In this case, It is necessary to split the incident light from the laser oscillator into a plurality of optical paths.

Conventionally, as a device for branching incident light from a laser oscillator into, for example, four optical paths, as shown in FIG. 9, a laser beam LB from a laser oscillator 1 is divided into three half mirrors 2.
Using four fiber incidence optical systems 3a, 3b, 3c,
An optical branching device of the simultaneous branching type that simultaneously branches to 3d, or, as shown in FIG. 10, four mirrors 5a, 5b, 5c, 5d are formed by using four actuators 4a, 4b, 4c, 4d such as solenoids. There is known a time-division branching type optical branching device that alternately drives the laser beams LB from the laser oscillator 1 and sequentially branches the laser beam LB from the laser oscillator 1 into four fiber incident optical systems 3a, 3b, 3c, 3d.

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional simultaneous branching type optical branching device, the laser light LB simultaneously receives four fiber incidence optical systems 3a, 3a.
Since the light is branched into b, 3c, and 3d, the power in each of the fiber incident optical systems 3a, 3b, 3c, and 3d becomes 1/4 of the laser light LB output from the laser oscillator 1.
Therefore, there is no particular problem when the power of the laser beam LB is sufficient for processing purposes such as welding and drilling, but there is a problem that it cannot be used otherwise.

On the other hand, although the conventional time-division branching type optical branching device cannot perform simultaneous multi-point processing, the power in each fiber incident optical system 3a, 3b, 3c, 3d is from the laser oscillator 1. The output laser light is the same as the output laser light LB, and there is an advantage that the low output laser oscillator 1 can be used.

However, in the conventional time-division branching type optical branching device, the optical path is switched by utilizing the reciprocating motion of the mirror,
Each mirror cannot branch the laser light LB to each fiber incident optical system 3a, 3b, 3c, 3d unless it is stopped at a regular position while crossing the incident light path of the laser light LB, and thus the optical path is Switching takes several hundreds of _msec, which makes it impossible to switch channels quickly. In particular, when a pulse laser is used to time-division one pulse at a time for branching into each optical path, if the pulse rate is high, branching becomes impossible, and the actuators 4a, 4b, 4c, 4d and the mirrors 5a, 5b, 5 are not possible.
There is a problem that the c and 5d are easily damaged.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical branching device capable of significantly shortening the channel switching time and capable of time-dividing a pulse laser with a high pulse rate one pulse at a time. To do.

[Means for Solving the Problems] As means for achieving the above object, the present invention includes a plurality of mirrors arranged at arbitrary intervals along an incident light path of incident light;
A mirror driving mechanism that holds each of these mirrors at a constant inclination with respect to the incident light and that rotates the mirror so as to traverse the incident light path at mutually different timings;
In addition to branching into multiple optical paths in time division,
The mirror driving mechanism is provided with a detecting means for detecting that a predetermined mirror is positioned on the incident light path, and the incident light is intermittently output by a detection signal from the detecting means. And

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

By the way, each mirror 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 incident angle 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 reduce the channel switching time. As a result, even a pulsed laser having a high pulse rate can be time-divided one pulse at a time.

And at this time, the mirror drive mechanism is provided with a detection means for detecting that a predetermined mirror is positioned on the incident optical path,
Since the incident light is intermittently output by the detection signal from this detecting means, the intermittent output of the incident light and the channel switching can be perfectly synchronized, and one pulse of the pulse laser is generated. The time division branch can be performed more safely.

[Embodiment] 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 is YA as shown in FIG.
Incident light 13 from a laser head 12 that oscillates a G laser
4 fiber incidence optical systems 3a, 3b, 3c, 3d
It is designed to branch in time division.

As shown in FIG. 1, the time division branching unit 11 is provided with four mirror members 15a, 15b, 15c, 15d arranged at predetermined intervals along the incident light path 14 of the incident light 13, and each of these mirror members 15a, 15b, 15c, 15d. Mirror members 15a, 15b, 15
The c and 15d are configured to be rotationally driven at a constant speed by the mirror drive mechanism 16 while maintaining an inclination angle of 45 degrees with respect to the incident light 13.

The respective mirror members 15a, 15b, 15c, 15d are
As shown in FIG. 3, the rotating shafts 17a, 17b, 17c,
Hub portion 18a pivotally attached to 17d, ring-shaped rim portion 1
8b, and a rotary plate 18 composed of four arm parts 18c interconnecting the hub part 18a and the rim part 18b with each other at 90 degree intervals. The rotary plate 18 is provided between adjacent arm parts 18c of the rotary plate 18. Is the three incident light passage windows 19 and the incident light 1
3 is the fiber incident optical system 3a, 3b, 3c, 3d
A single mirror 20a, 20b, 20 for reflecting
c and 20d are provided respectively. The respective mirror members 15a, 15b, 15c, 15d are set so that the respective mirrors 20a, 20b, 20c, 20d are displaced by 90 degrees.
a, 20b, 20c, 20d are mirror members 15a,
When the mirror driving mechanism 16 rotationally drives 15b, 15c, and 15d at a constant speed, the incident optical path 14 is traversed by mutually different timing nags.

The timing at which each of these mirrors 20a, 20b, 20c, 20d crosses the incident light path 14 is as shown in FIGS. 1 and 3, and each mirror member 15a, 15b, 15c, 1
Sensor 21 such as a proximity switch arranged corresponding to 5d
a, 21b, 21c, 21d and each mirror member 15a,
15b, 15c, 15d and the detection pieces 22 provided on the outer peripheral portions of the rim portions 18b, respectively, and the detection signals from the sensors 21a, 21b, 21c, 21d are as shown in FIG. Is input to the laser power supply 24 as a trigger pulse via the channel changeover switch 23, and the laser head 12 outputs pulsed laser light as incident light 13 in response to the input of this trigger pulse. This will be described later in detail.

On the other hand, as shown in FIG. 1, the mirror driving mechanism 16 is provided with a motor 25 that rotates at a constant speed, and the output shaft 26 of the motor 25 has the rotating shafts 17a and 17a.
belt wheels 27a, 27 attached to b, 17c, 17d
b, 27c, 27d, endless timing belt 28
Belt wheels 29a, 29b, 29c, and 29d connected via a, 28b, 28c, and 28d are axially mounted, respectively. Then, each of the mirror members 15a, 15b, 1
5c and 15d are driven to rotate at a constant speed by the rotation of the motor 25.

1 and 2, reference numerals 30a, 30
b, 30c, 30d are the fiber incident optical systems 3
Optical fiber cables connected to a, 3b, 3c, and 3d, respectively.

Next, the operation of this embodiment will be described.

When the motor 25 is started, its output shaft 26 rotates at a constant speed, and its rotational force is changed by the belt wheels 29a, 29b, 29c,
29d, 27a, 27b, 27c, 27d and timing belts 28a, 28b, 28c, 28d are transmitted to the respective rotary shafts 17a, 17b, 17c, 17d, and the respective mirror members 15a, 15b, 15c, 15d are at a constant speed. It is driven to rotate.

By the way, each mirror member 15a, 15b, 15c, 15
d is rotated while maintaining an inclination angle of 45 degrees with respect to the incident light 13 and each of the mirrors 20a, 20b, 20c and 20d is 9 °.
Since the mirrors 20a, 20b, 20c, and 20d are set so as to be shifted by 0 degrees, the mirrors 20a, 20b, 20c, and 20d cross the incident light path 14 at different timings while maintaining a constant inclination angle with respect to the incident light 13. Become. The timing at which each mirror 20a, 20b, 20c, 20d crosses the incident optical path 14 is determined by the corresponding sensor 21a,
21b, 21c, and 21d, respectively.

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

For example, when CH1 (corresponding to the sensor 21a) is selected by the channel changeover switch 23, the mirror 20a
When the laser beam crosses the incident optical path 14, the laser head 1
The incident light 13 is output from 2 and therefore the incident light 13
Is reflected by the mirror 20a and branched to the fiber incident optical system 3a. CH2 (corresponding to sensor 21b), CH3
The same applies to (corresponding to the sensor 21c) and CH4 (corresponding to the sensor 21d). In addition, by using the channel changeover switch 23, all channels CH1, CH
When 2, CH3 and CH4 are selected, each sensor 21
Detection signals from a, 21b, 21c, and 21d are sequentially input to the laser power source 24 as trigger pulses, and the laser head 12 outputs pulsed laser light as incident light 13 in accordance with this. FIG. 4 shows this state. In this case, the incident light 13 is time-divisionally branched into the fiber incident optical systems 3a, 3b, 3c, and 3d, one pulse at a time. The pulse rate in that case is determined by the rotational speeds of the mirror members 15a, 15b, 15c, 15d. In FIG. 4, reference numeral R indicates each mirror member 1.
The time for one rotation of 5a, 15b, 15c, and 15d is shown.

Then, each mirror 20a, 20b, 20c, 20d
Is driven to rotate with a constant inclination angle with respect to the incident light 13, so that even if the mirrors 20a, 2a are rotated at all times,
The incident angle of the incident light 13 with respect to 0b, 20c, and 20d does not change, and therefore the optical axis does not shift. Therefore, the channel switching time can be greatly shortened, and a pulse laser with a high pulse rate can also be time-divisionally branched one pulse at a time. And the pulse rate is
Since it is determined by the rotation speeds of the mirrors 20a, 20b, 20c, 20d, the pulse laser and the channel switching can be perfectly synchronized.

FIG. 5 shows a second embodiment of the present invention.
Instead of the mirror member 15d in the embodiment, a fixed mirror 31 is installed on the incident light path 14 of the incident light 13, and a rotating plate 18 having no mirror 20d is provided at a position deviated from the incident light path 14 and a sensor is provided in the vicinity thereof. 20d is installed. The other points are the same as those of the first embodiment.

Even with this structure, the same effect as that of 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 incident optical system 3d is arranged on the incident optical path 14 of the incident light 13. Regarding other points,
It has the same structure as the second embodiment.

With this structure, the same effect can be expected with a small number of parts.

FIGS. 7 and 8 show a fourth embodiment of the present invention in which the position detection of each mirror and the channel switching can be performed by one sensor.

That is, on the output shaft 26 of the motor 25, as shown in FIG. 7, a predetermined number of mirror position detection plates S ₁ , S ₂ ,.
S _n-1 and S _n are provided at regular intervals, and the sensor 41
Can be slid along the mirror position detecting plates S ₁ , S ₂ , ..., S _n-1 , S _n as shown by a double-headed arrow in FIG.

Each of the mirror position detection plates S ₁ , S ₂ , ..., S _n-1 , S
_As shown in FIG. 8, each of the mirrors 20a is provided with a detection piece 22 at the position of the channel to be selected. For example, when the sensor 41 is associated with the mirror position detection plate S _n , , 20b, 20c, 20d (see FIG. 3) crosses the incident optical path 14 at the sensor 41.
By sequentially inputting the detection signal from the sensor 41 to the laser power source 24 as a trigger pulse, pulsed laser light similar to that in the case of FIG.
The incident light 13 is output from the light source 2.
The other points are the same as those of the first embodiment.

Thus, with this configuration, one sensor 41 can detect the mirror position and switch the channel, and the structure can be simplified.

In each of the above embodiments, each mirror member 15a,
The case where the inclination angles of 15b, 15c, and 14d with respect to the incident light 13 are all the same has been described.
On the other hand, if the mirror members 15a, 15b, 15c, and 15d are rotated while maintaining a constant tilt angle, the tilt angles of the mirror members 15a, 15b, 15c, and 15d do not have to have the same value.

Further, in each of the above-mentioned embodiments, the case of branching into four channels has been described, but the number is not limited as long as it branches into two or more channels. Further, not only the YAG laser but also another laser can be used, and the same can be applied to the time division branching of light other than the laser.

Further, in each of the above-mentioned embodiments, the output form of the pulsed laser light outputted as the incident light 13 from the laser head 12 was not particularly described, but the pulsed light having any waveform can be similarly applied.

EFFECTS OF THE INVENTION As described above, according to the present invention, a plurality of mirrors arranged at arbitrary intervals along the incident light path of incident light and each of these mirrors are rotated while maintaining a constant inclination angle with respect to the incident light. And a mirror driving mechanism for driving each of the mirrors so as to cross the incident optical path at different timings, the channel switching time can be greatly shortened, and the pulse laser has a high pulse rate. Also, one pulse can be time-divisionally branched.

At this time, the mirror driving mechanism is provided with a detecting means for detecting that a predetermined mirror is positioned on the incident light path, and the incident light is intermittently output by the detection signal from the detecting means. Therefore, the intermittent output of the incident light and the channel switching can be perfectly synchronized,
The time-division branching of each pulse of the pulse laser can be performed more stably.

[Brief description of drawings]

FIG. 1 is a detailed view of essential parts showing 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 a configuration of a mirror member, and FIG. A time chart showing the relationship between the detection signal of each sensor, the trigger pulse, and the incident light, FIG. 5 is a view corresponding to FIG. 1 showing a second embodiment of the present invention,
FIG. 6 is a view corresponding to FIG. 1 showing the third embodiment of the present invention, and FIG.
FIG. 8 is a block diagram of the essential parts showing a fourth embodiment of the present invention, FIG. 8 is an explanatory diagram showing the structure of each mirror position detection plate of FIG. 7, and FIG. 9 is a conventional optical branching device of the simultaneous branching system. FIG. 10 is a block diagram showing a conventional optical branching device of a time division branching system. 3a, 3b, 3c, 3d: Fiber incident optical system 11: Time division branching unit 13: Incident light, 14: Incident light path 15a, 15b, 15c, 15d: Mirror member 16: Mirror drive mechanism 20a, 20b, 20c, 20d: mirrors 21a, 21b, 21c, 21d: sensor 22: detecting piece 23: channel change-over switch 24: laser power supply, 31: fixed mirror _{S 1, S 2, ...,} S n-1, S n: mirror detection plate

Claims (1)

[Claims] 1. An optical branching device for branching an incident light having an arbitrary diameter into a plurality of optical paths, and a plurality of mirrors arranged at arbitrary intervals along the incident optical path of the incident light; A mirror driving mechanism that holds a certain inclination angle with respect to the incident light and that rotates so as to traverse the incident light path at mutually different timings; and the mirror driving mechanism has a predetermined mirror located on the incident light path. An optical branching device having a detecting means for detecting that the incident light is intermittently output by a detection signal from the detecting means.