Optical scanning device and laser machining device

Patent metadata

Field	Value
Publication number	US-9529190-B2
Application number	US-201314388958-A
Country	US
Kind code	B2
Filing date	Mar 25, 2013
Priority date	Mar 29, 2012
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An optical scanning device includes: a projector configured to radiate laser light incident thereon while causing the laser light to make angular movement around a projection center, and a reflector with a parabolic surface, the reflector being configured to reflect the laser light from the projector. The projection center is positioned at a focal point of the parabolic surface. The projector radiates the laser light such that the greater a difference between a rotation angle of the laser light and a reference angle, the lower an angular speed of the laser light, the reference angle being the rotation angle of the laser light when the laser light reflects on a vertex of the parabolic surface. A laser machining device includes the optical scanning device, and is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line.

First claim

The invention claimed is:

1. An optical scanning device comprising:
a projector configured to radiate laser light while causing the laser light to make angular movement around a projection center; and
a reflector with a parabolic surface, the reflector being configured to reflect the laser light from the projector, wherein
the projection center is positioned at a focal point of the parabolic surface, and
the projector radiates the laser light while causing the laser light to make the angular movement at a non-constant speed, such that the greater a difference between a rotation angle of the laser light and a reference angle, the lower an angular speed of the laser light, the reference angle being the rotation angle of the laser light when the laser light reflects on a vertex of the parabolic surface.

2. The optical scanning device according to claim 1 , wherein
the projector includes a multifaceted rotating mirror with a plurality of reflecting surfaces,
a single scanning line is formed while the laser light that is incident on the multifaceted rotating mirror is passing across one of the plurality of reflecting surfaces, and
a rotation angle of the multifaceted rotating mirror passes the reference angle while the single scanning line is being formed.

3. The optical scanning device according to claim 2 , wherein when the rotation angle of the laser light is the reference angle, the laser light is incident on a middle point of any one of the plurality of reflecting surfaces.

4. The optical scanning device according to claim 1 , wherein
the projector radiates the laser light while causing the laser light to make the angular movement in such a manner as to satisfy ω=V x /a {1+(V x ×t/2a) 2 } in a case where:
a distance between the focal point and the vertex is a;
a scanning speed of the laser light is V x ;
a time that has elapsed from a point when the rotation angle of the laser light is the reference angle is t; and
the angular speed of the laser light is ω.

5. A laser machining device comprising the optical scanning device according to claim 1 , wherein
the laser machining device is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line in the workpiece.

6. The laser machining device according to claim 5 , comprising a conveying apparatus configured to convey the workpiece in a conveyance direction at a constant conveyance speed, wherein
the parabolic surface is disposed in such a manner as to extend in a direction crossing the conveyance direction, and
the projector is operated continuously while the conveying apparatus is conveying the workpiece, such that a plurality of machining lines each extending in a scanning direction perpendicular to the conveyance direction are formed in the workpiece in such a manner that the plurality of machining lines are arranged side by side in the conveyance direction.

7. The optical scanning device according to claim 2 , wherein
the projector radiates the laser light while causing the laser light to make the angular movement in such a manner as to satisfy ω=V x /a {1+(V x ×t/2a) 2 } in a case where:
a distance between the focal point and the vertex is a;
a scanning speed of the laser light is V x ;
a time that has elapsed from a point when the rotation angle of the laser light is the reference angle is t; and
the angular speed of the laser light is ω.

8. The optical scanning device according to claim 3 , wherein
the projector radiates the laser light while causing the laser light to make the angular movement in such a manner as to satisfy ω=V x /a {1+(V x ×t/2a) 2 } in a case where:
a distance between the focal point and the vertex is a;
a scanning speed of the laser light is V x ;
a time that has elapsed from a point when the rotation angle of the laser light is the reference angle is t; and
the angular speed of the laser light is ω.

9. A laser machining device comprising the optical scanning device according to claim 2 , wherein
the laser machining device is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line in the workpiece.

10. A laser machining device comprising the optical scanning device according to claim 3 , wherein
the laser machining device is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line in the workpiece.

11. A laser machining device comprising the optical scanning device according to claim 4 , wherein
the laser machining device is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line in the workpiece.

12. A laser machining device comprising the optical scanning device according to claim 7 , wherein
the laser machining device is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line in the workpiece.

13. A laser machining device comprising the optical scanning device according to claim 8 , wherein
the laser machining device is configured to cause the laser light from the reflector to fall on a workpiece to form a machining line in the workpiece.

14. The laser machining device according to claim 9 , comprising a conveying apparatus configured to convey the workpiece in a conveyance direction at a constant conveyance speed, wherein
the parabolic surface is disposed in such a manner as to extend in a direction crossing the conveyance direction, and
the projector is operated continuously while the conveying apparatus is conveying the workpiece, such that a plurality of machining lines each extending in a scanning direction perpendicular to the conveyance direction are formed in the workpiece in such a manner that the plurality of machining lines are arranged side by side in the conveyance direction.

15. The laser machining device according to claim 10 , comprising a conveying apparatus configured to convey the workpiece in a conveyance direction at a constant conveyance speed, wherein
the parabolic surface is disposed in such a manner as to extend in a direction crossing the conveyance direction, and
the projector is operated continuously while the conveying apparatus is conveying the workpiece, such that a plurality of machining lines each extending in a scanning direction perpendicular to the conveyance direction are formed in the workpiece in such a manner that the plurality of machining lines are arranged side by side in the conveyance direction.

16. The laser machining device according to claim 11 , comprising a conveying apparatus configured to convey the workpiece in a conveyance direction at a constant conveyance speed, wherein
the parabolic surface is disposed in such a manner as to extend in a direction crossing the conveyance direction, and
the projector is operated continuously while the conveying apparatus is conveying the workpiece, such that a plurality of machining lines each extending in a scanning direction perpendicular to the conveyance direction are formed in the workpiece in such a manner that the plurality of machining lines are arranged side by side in the conveyance direction.

17. The laser machining device according to claim 12 , comprising a conveying apparatus configured to convey the workpiece in a conveyance direction at a constant conveyance speed, wherein
the parabolic surface is disposed in such a manner as to extend in a direction crossing the conveyance direction, and
the projector is operated continuously while the conveying apparatus is conveying the workpiece, such that a plurality of

Assignees

• Kawasaki Heavy Ind Ltd

Inventors

• Nakazawa Mutsuhiro
• Takahara Kazunori
• Oogushi Osami

Classifications

• H10F10/00

  Individual photovoltaic cells, e.g. solar cells (electrolytic light-sensitive devices, e.g. dye-sensitised solar cells, H01G9/20) · CPC title

• H01L31/04

  Electricity · mapped topic

• G02B26/122 Primary

  Control of the scanning speed of the polygonal mirror · CPC title

• B23K26/0846

  for moving elongated workpieces longitudinally, e.g. wire or strip material · CPC title

• B23K26/0821

  using multifaceted mirrors, e.g. polygonal mirror · CPC title