JP2009003167A - Beam-sorting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a beam-sorting device having a new configuration. <P>SOLUTION: The beam-sorting device comprises a first deflector which can take, by external control, any one of among a state for deflecting beam in a first direction within a virtual plane, a state for deflecting the beam in a second direction, and a state for straightly propagating the beam; a second deflector which is disposed on the optical path of the beam straightly propagating in the first deflector and can assume either a state for deflecting the beam, in a third direction within the virtual plane or a state for deflecting the beam in a fourth direction; and a control device which controls the first deflector so that the beam incident on the first deflector straightly propagates or goes out, while being deflected in the first or second direction, and controls the second deflector so that the beam incident on the second deflector goes out, while being deflected in the third or fourth direction. With the outgoing direction of the beam propagating straight in the first deflector, the first and second directions are inclined in the same direction, the third and fourth directions are inclined in the same direction, and the first and third directions are inclined in the opposite directions. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a beam distribution device that can distribute and emit a beam incident from one direction in a plurality of directions.

  An acousto-optic deflector (AOD) is known as a deflector that emits an incident laser beam in different directions.

  When a high-frequency electric signal (AC voltage) is applied to the AOD, an ultrasonic coarse / fine wave synchronized with the electric signal is generated in the AOD acousto-optic medium. This dense wave acts as a diffraction grating, and a part of the incident laser beam is Bragg reflected (acousto-optic effect), deflected and emitted.

  The diffraction angle of the laser beam depends on the frequency of the dense wave. The diffraction angle can be continuously changed by continuously changing the frequency of the dense wave. The frequency of the dense wave can be controlled by changing the frequency of the electric signal. In addition, when an electric signal is not applied to AOD, laser beam diffraction does not occur.

  The maximum angle at which the laser beam can be deflected by AOD is, for example, about 8 °. For this reason, for example, when a single AOD is used to deflect laser beams equally in four directions, the angle between adjacent deflected laser beams becomes as small as about 2.66 °. In order to separate these deflected laser beams, the laser beams need to travel a sufficiently long distance. Further, when the beam divergence angle of the laser beam is larger than the angle between the laser beams, the laser beam cannot be separated no matter how long it travels.

  Inventions of various laser processing apparatuses using AOD are disclosed (for example, see Patent Documents 1 and 2).

  In addition, a technique for splitting a laser beam into four parts using three AODs is known.

JP 2000-263271 A JP 2004-191880 A

  An object of the present invention is to provide a beam distribution device having a novel configuration.

  According to one aspect of the present invention, a state in which an incident laser beam is deflected in a first direction within one virtual plane by external control, in a second direction different from the first direction. A first deflector that can take either a deflected state or a straightly advanced state, and a laser that is disposed on the optical path of a laser beam that has traveled straight through the first deflector and that is incident by external control A state in which the beam is deflected in a third direction different from both the first direction and the second direction in the virtual plane, or a fourth direction different from any of the first to third directions. A second deflector capable of taking any of the following states: and a laser beam incident on the first deflector travels straight or deflects in the first or second direction. Said first so as to exit A control device for controlling the second deflector so as to control the deflector and to emit a laser beam incident on the second deflector in the third or fourth direction. The first direction and the second direction are inclined in the same direction with reference to the emission direction of the laser beam that travels straight through the first deflector, and the third direction and the fourth direction. Is provided with a beam distribution device in which the first direction and the third direction are inclined in directions opposite to each other.

  According to another aspect of the present invention, a state in which an incident laser beam is deflected in a first direction within a first virtual plane by a control from the outside, a second different from the first direction. A first deflector capable of taking either a state of deflecting in the direction of or a state of going straight, and an optical path of a laser beam that has traveled straight through the first deflector, A state in which an incident laser beam is deflected in a third direction different from both the first direction and the second direction in a second virtual plane intersecting the first virtual plane; A second deflector capable of taking a state of deflecting in a fourth direction different from any of the third to third directions, and a laser beam incident on the first deflector traveling straight ahead, or , The first or second direction The first deflector is controlled so as to be deflected and emitted, and the laser beam incident on the second deflector is deflected and emitted in the third or fourth direction. And a beam distribution device having a control device for controlling the two deflectors.

  ADVANTAGE OF THE INVENTION According to this invention, the beam distribution apparatus of a novel structure can be provided.

  FIG. 1 is a schematic view showing a beam irradiation apparatus including a beam distribution apparatus according to the first embodiment.

  The beam irradiation apparatus shown in the figure includes a laser light source 1, folding mirrors 2a to 2u, a mask 3, AODs 4a and 4b, a damper 5, galvano scanners 6a to 6d, processing lenses 7a to 7d, stages 8a and 8b, and a control device. 9 is comprised.

  The laser light source 1 receives a signal transmitted from the control device 9 and emits a pulsed laser beam Lb. The pulse laser beam Lb is reflected by the folding mirrors 2 a to 2 c and enters the mask 3.

  The mask 3 includes a light transmitting area and a light shielding area. The pulse laser beam Lb is shaped in cross section by passing through the light transmitting region of the mask 3. The pulse laser beam Lb that has passed through the translucent region of the mask 3 is reflected by the folding mirror 2d and enters the AOD 4a.

  The AOD 4a receives a high-frequency electric signal (AC voltage) sent from the control device 9 and changes the emission direction of the pulse laser beam Lb.

An AC voltage having a frequency f ₁ or an AC voltage having a frequency f ₂ that is lower than f ₁ is applied to the AOD 4a. When an AC voltage having a frequency f ₁ is applied, the pulse laser beam Lb is deflected by the deflection angle θ ₁ and emitted from the AOD 4a. This laser beam is referred to as a pulsed laser beam Lba. When an AC voltage having a frequency f ₂ is applied, the pulse laser beam Lb is deflected by a deflection angle θ ₂ smaller than the deflection angle θ ₁ and is emitted from the AOD 4a. This laser beam is referred to as a pulsed laser beam Lbb.

The pulse laser beam Lb incident on the AOD 4a when no AC voltage is applied to the AOD 4a travels straight and enters the AOD 4b. Even when an AC voltage having the frequency f ₁ or f ₂ is applied to the AOD 4a, a part (approximately several to 20%) of the pulse laser beam Lb travels straight as leakage light. This leakage light also enters the AOD 4 b and is absorbed by the damper 5.

  The AOD 4b also receives a high-frequency electric signal (AC voltage) sent from the control device 9 and changes the emission direction of the pulse laser beam Lb.

An AC voltage having a frequency f ₁ or an AC voltage having a frequency f ₂ that is lower than f ₁ is also applied to the AOD 4b. When an alternating voltage of frequency f ₁ is applied, the pulse laser beam Lb is deflected by the deflection angle θ ₁ and emitted from the AOD 4b. This laser beam is referred to as a pulsed laser beam Lbc. When an AC voltage having a frequency f ₂ is applied, the pulse laser beam Lb is deflected by a deflection angle θ ₂ smaller than the deflection angle θ ₁ and is emitted from the AOD 4 b. This laser beam is referred to as a pulsed laser beam Lbd.

The AOD 4a and the AOD 4b are opposite to each other with the pulse laser beams Lba and Lbb and the pulse laser beams Lbc and Lbd being in the same plane and having a deflection direction that is emitted from the AOD 4a without being deflected. It arrange | positions so that it may radiate | emit in direction. Therefore the angle is 2 × theta ₁ next to the emission direction of the emission direction and the pulse laser beam Lbc of the pulse laser beam Lba, the angle is 2 × the emission direction of the emission direction and the pulse laser beam Lbd pulsed laser beam Lbb the θ _2.

The pulse laser beam Lb incident on the AOD 4b when no AC voltage is applied to the AOD 4b travels straight and enters the damper 5 and is absorbed. Even when an AC voltage having the frequency f ₁ or f ₂ is applied to the AOD 4b, a part (approximately several to 20%) of the pulse laser beam Lb travels straight as leak light. This leaked light also enters the damper 5 and is absorbed.

Pulsed laser beam Lba emitted to be deflected AOD4a only deflection angle theta ₁ is reflected by the folding mirror 2E～2g, it is entered into the Galvano scanner 6a. The galvano scanner 6a includes two oscillating mirrors, and scans and emits an incident pulse laser beam Lba in a two-dimensional direction. A workpiece is held on the stages 8a and 8b. The pulsed laser beam Lba emitted from the galvano scanner 6a passes through the processing lens 7a and enters the processing object on the stage 8a. The processing lens 7a causes the pulsed laser beam Lba to enter the processing target perpendicularly.

The same applies to the pulse laser beam Lbb deflected by the deflection angle θ ₂ and emitted from the AOD 4a, the pulse laser beam Lbc deflected by the deflection angle θ ₁ and emitted from the AOD 4b, and the pulse laser beam Lbd deflected by the deflection angle θ ₂ and emitted from the AOD 4b. The workpieces held on the stage 8a or 8b are respectively passed through the folding mirrors 2h to 2j, 2k to 2p, 2q to 2u, the galvano scanners 6b, 6c, 6d, and the processing lenses 7b, 7c, 7d. Incident.

  The beam distribution apparatus according to the first embodiment includes two AODs 4a and 4b arranged in series so that the beam deflection directions are opposite to each other in the same plane. By setting the deflection directions to be opposite to each other in the same plane, it is possible to easily arrange other optical elements of the beam irradiation apparatus, for example, folding mirrors. Further, the beam irradiation apparatus can be reduced in size.

  FIG. 2 is a schematic view showing a beam irradiation apparatus including a beam distribution apparatus according to the second embodiment.

  The beam irradiation apparatus shown in this figure and the beam irradiation apparatus shown in FIG. 1 differ in the relative arrangement of AOD 4a and AOD 4b. In the beam irradiation apparatus shown in FIG. 1, the AOD 4a and the AOD 4b are arranged so that the pulse laser beams Lba and Lbb and the pulse laser beams Lbc and Lbd are emitted in the same plane. In the beam irradiation apparatus shown in this drawing, the AOD 4a and the AOD 4b are arranged so that the pulse laser beams Lba and Lbb and the pulse laser beams Lbc and Lbd are deflected in different planes (in planes crossing each other). Due to this arrangement, the beam irradiation apparatus shown in the figure does not include the two mirrors, the folding mirrors 2m and 2r.

  The beam distribution apparatus according to the second embodiment deflects the incident pulse laser beam in different planes by using the AOD 4a and the AOD 4b. For this reason, the optical system installation area of a beam irradiation apparatus can be reduced. In addition, the number of folding mirrors can be reduced. For this reason, the beam irradiation apparatus can be further reduced in size compared with the case where the beam distribution apparatus according to the first embodiment is used. Furthermore, the optical design of the beam irradiation device can be performed more easily than when the beam distribution device according to the first embodiment is used.

  A beam distribution method according to the embodiment will be described with reference to FIGS.

  FIG. 3A shows the relationship between the time (time) of the pulse laser beam Lb incident on the AOD 4a and the laser intensity. The horizontal axis represents time, and the vertical axis represents laser intensity. In the beam distribution method according to the embodiment, two continuous laser pulses incident on the AOD 4a are divided into two along the time axis by the AODs 4a and 4b and emitted in four directions.

Laser pulses incident on AOD4a at constant laser intensity at time _t 1 ~t ₃ (first laser pulse) and the time _t 4 ~t ₆ (second laser pulse). The pulse width and laser intensity of the first laser pulse and the second laser pulse are equal to each other. Further, the laser pulse is oscillated at a constant repetition frequency.

  FIG. 3B shows the timing of voltage application to the AOD 4a. The horizontal axis represents time, and the vertical axis represents the frequency (input frequency) of the voltage applied to the AOD 4a.

At time t _{1 to} t ₂ , an AC voltage having a frequency f ₁ is applied to the AOD 4a. Further, at time _t 2 ~t _3, an AC voltage of frequency _{f 2} is applied to the AOD4a. And AC voltage of the AC voltage and frequency f ₂ of the frequency f ₁ may be applied to the reverse.

  FIG. 3C shows the timing of voltage application to the AOD 4b. The horizontal axis represents time, and the vertical axis represents the frequency (input frequency) of the voltage applied to the AOD 4b.

At time _t 4 ~t _5, AC voltage of frequency _{f 1} is applied to the AOD 4B. Further, at time _t 5 ~t _6, an AC voltage of frequency _{f 2} is applied to the AOD 4B.

  FIG. 3D shows the relationship between the time (time) of the laser beams Lba to Lbd emitted by being separated into four different directions by the AODs 4a and 4b and the laser intensity. The horizontal axis represents time, and the vertical axis represents laser intensity.

The laser beam Lba is emitted from time t _{1 to} t ₂ when the AC voltage having the frequency f ₁ is applied to the AOD 4a, and the laser is generated from time t _{2 to} t ₃ when the AC voltage having the frequency f ₂ is applied to the AOD 4a. A beam Lbb is emitted.

In addition, the laser beam Lbc is emitted from time t _{4 to} t ₅ when no voltage is applied to the AOD 4a and the AC voltage having the frequency f ₁ is applied to the AOD 4b, and no voltage is applied to the AOD 4a. At time _t 5 ~t ₆ an AC voltage of frequency _{f 2} is applied, the laser beam Lbd is emitted.

  In this way, two consecutive laser pulses can be divided into two along the time axis and can be advanced in four different directions.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto.

For example, AC voltages having the same frequency (frequency f ₁ and f ₂ ) are applied to the AODs 4a and 4b, but AC voltages having different frequencies may be applied to the AOD 4a and the AOD 4b.

  In the embodiment, two continuous laser pulses are each divided into two along the time axis and traveled in four different directions, but one laser pulse is divided into four along the time axis, You may distribute in four different directions.

  FIG. 4 shows an example thereof. The operations of the AODs 4a to 4d and the laser beams Lba to Lbd shown in FIG. 3 are the same.

  Furthermore, it is possible to distribute four consecutive laser pulses in four different directions.

  In the embodiment, a laser light source that emits a pulse laser beam is used. However, a laser light source may be configured using a laser oscillator that emits a continuous wave.

  It will be apparent to those skilled in the art that other various modifications, improvements, combinations, and the like can be made.

  It can be used for laser processing in general.

It is the schematic which shows the beam irradiation apparatus containing the beam distribution apparatus by 1st Example. It is the schematic which shows the beam irradiation apparatus containing the beam distribution apparatus by the 2nd Example. (A)-(D) is a figure for demonstrating the 2 beam 4 axis | shaft allocation method by an Example. (A)-(D) is a figure for demonstrating the 1 beam 4 axis | shaft allocation method by an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser light source 2a-2u Folding mirror 3 Mask 4a, 4b AOD
5 Damper 6a-6d Galvano scanner 7a-7d Processing lens 8a, 8b Stage 9 Control device Lb, Lba-Lbd Laser beam

Claims (6)

A state in which an incident laser beam is deflected in a first direction, a state in which the incident laser beam is deflected in a second direction different from the first direction, and a state in which the laser beam is caused to go straight by control from the outside. A first deflector capable of taking either
The laser beam is arranged on the optical path of the laser beam that has traveled straight through the first deflector, and is incident on the laser beam in either the first direction or the second direction within the virtual plane by external control. A second deflector capable of taking either a state of deflecting in a different third direction or a state of deflecting in a fourth direction different from any of the first to third directions;
The first deflector is controlled so that the laser beam incident on the first deflector travels straight or is deflected in the first or second direction, and the second deflector is emitted. A control device for controlling the second deflector so that the laser beam incident on the deflector is deflected in the third or fourth direction and emitted.
The first direction and the second direction are inclined in the same direction, with the laser beam traveling straight through the first deflector as a reference, and the third direction and the fourth direction are the same. A beam distribution device that is inclined in a direction, and wherein the first direction and the third direction are inclined in directions opposite to each other. And a light source that emits a laser beam incident on the first deflector by external control,
The controller is
Two laser pulses are emitted from the light source, and within the pulse width of the laser pulse emitted earlier, within the pulse width of the beam pulse emitted after the first to third times and over time. When the 4th to 6th time is set along the passage of time,
The first deflector has a time from the first time to the second time, a time from the second time to the third time, and from the fourth time to the fifth time. And one of the four times from the fifth time to the sixth time, the incident laser beam is deflected and emitted in the first direction, and the other one In time, the incident laser beam is deflected and emitted in the second direction,
The second deflector deflects the incident laser beam in the third direction in one of two times in which the first deflector advances the laser beam straight in the four times. The light source and the first and second deflectors are controlled so that the incident laser beam is deflected and emitted in the fourth direction at another time. The beam distribution apparatus as described.   The beam distribution device according to claim 1 or 2, wherein the first and second deflectors are acousto-optic deflectors. A state in which an incident laser beam is deflected in a first direction, a state in which the incident laser beam is deflected in a second direction different from the first direction, and a state in which the laser beam is linearly moved by control from the outside. A first deflector that can take any of the following:
The first deflector is disposed on the optical path of the laser beam that has traveled straight through the first deflector, and the first laser beam is incident on the first virtual plane in a second virtual plane that intersects the first virtual plane by external control. , A state of deflecting in a third direction different from any of the second directions, and a state of deflecting in a fourth direction different from any of the first to third directions. Two deflectors;
The first deflector is controlled so that the laser beam incident on the first deflector travels straight or is deflected in the first or second direction, and the second deflector is emitted. And a controller for controlling the second deflector so that the laser beam incident on the deflector is deflected and emitted in the third or fourth direction. And a light source that emits a laser beam incident on the first deflector by external control,
The controller is
Two laser pulses are emitted from the light source, and within the pulse width of the laser pulse emitted earlier, within the pulse width of the beam pulse emitted after the first to third times and over time. When the 4th to 6th time is set along the passage of time,
The first deflector has a time from the first time to the second time, a time from the second time to the third time, and from the fourth time to the fifth time. And one of the four times from the fifth time to the sixth time, the incident laser beam is deflected and emitted in the first direction, and the other one In time, the incident laser beam is deflected and emitted in the second direction,
The second deflector deflects the incident laser beam in the third direction in one of two times in which the first deflector advances the laser beam straight in the four times. The light source and the first and second deflectors are controlled so that the incident laser beam is deflected and emitted in the fourth direction at another time. The beam distribution apparatus as described.   6. The beam distribution device according to claim 4, wherein the first and second deflectors are acousto-optic deflectors.

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