Optical scanning device

Patent metadata

Field	Value
Publication number	US-11237384-B2
Application number	US-201916702734-A
Country	US
Kind code	B2
Filing date	Dec 4, 2019
Priority date	Dec 21, 2018
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

An optical scanning device includes a mirror that includes a mirror reflection surface, and torsion bars that support the corresponding sides of the mirror and cause the mirror to rotate. The torsion bars are formed of a silicon active layer whose surface is exposed.

First claim

What is claimed is:

1. An optical scanning device, comprising:
a mirror that includes a mirror reflection surface; and
torsion bars that support corresponding sides of the mirror and cause the mirror to rotate,
wherein the torsion bars are formed of a silicon active layer whose surface is exposed.

2. The optical scanning device as claimed in claim 1 , wherein an upper surface, a lower surface, and side surfaces of the silicon active layer forming the torsion bars are exposed.

3. The optical scanning device as claimed in claim 1 , wherein the mirror reflection surface is formed in a region of the silicon active layer other than regions where the torsion bars are formed.

4. The optical scanning device as claimed in claim 3 , wherein the mirror reflection surface is formed of a metal film that is formed on the silicon active layer via an oxide film.

5. The optical scanning device as claimed in claim 4 , further comprising:
a reflectance increasing film that is formed on the mirror reflection surface.

6. The optical scanning device as claimed in claim 5 , further comprising:
a rib that is formed under the region of the silicon active layer where the mirror reflection surface is formed.

7. The optical scanning device as claimed in claim 6 , wherein the rib is formed by patterning a support substrate disposed on a lower surface of the silicon active layer via a buried oxide layer.

8. The optical scanning device as claimed in claim 1 , further comprising:
horizontal driving beams that are connected to the torsion bars and configured to cause the mirror to rotate in a horizontal direction by resonant driving.

9. The optical scanning device as claimed in claim 8 , further comprising:
a movable frame that supports the horizontal driving beams and surrounds the torsion bars and the horizontal driving beams; and
vertical driving beams configured to cause the movable frame to rotate in a vertical direction, wherein
the torsion bars are arranged on a same straight line that is parallel to a longitudinal direction of the vertical driving beams.

Assignees

• Maruyama Yuki
• Mitsumi Electric Co Ltd

Inventors

• Maruyama Yuki

Classifications

• G02B26/105 Primary

  with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence) · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title

• G02B26/0858 Primary

  the reflecting means being moved or deformed by piezoelectric means · CPC title

• G02B26/10

  Scanning systems · CPC title