Optical scanning unit, and apparatus including the optical scanning unit

Patent metadata

Field	Value
Publication number	US-9348134-B2
Application number	US-201414456161-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Aug 23, 2013
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

An optical scanning unit includes a light source, an optical deflector that includes a light transmission window disposed on a light path from the light source and a rotatable mirror that includes a reflecting surface to reflect light that goes through the light transmission window into the light transmission window and to deflect the light from the light source toward a surface, and a light shield disposed on a light path of reflected light of the light from the light source reflected by a surface of the light transmission window.

First claim

What is claimed is:

1. An optical scanning unit, comprising:
a light source;
an optical deflector to deflect light from the light source toward a surface to be scanned, the optical deflector including a first side surface and a second side surface parallel to the first side surface, the optical deflector comprising:
a light transmission window disposed on a light path of light irradiated from the light source, the light transmission window supported by the first and second side surfaces; and
a rotatable mirror including a reflecting surface that reflects light transmitted through the light transmission window toward the surface; and
a light shield disposed on a light path of reflected light of the light from the light source that is reflected by a surface of the light transmission window,
wherein a height of the first side surface is longer than a height of the second side surface such that the light transmission window is not parallel to the rotatable mirror.

2. The optical scanning unit according to claim 1 , wherein the mirror is rotatable within a predetermined range around at least one axis, and the reflecting surface is not parallel to the surface of the light transmission window.

3. The optical scanning unit according to claim 1 , wherein the light path of the light from the light source and the light path of the reflected light are located on the same side of the light path of the light deflected by the optical deflector.

4. The optical scanning unit according to claim 1 , wherein the light path of the light from the light source and the light path of the light deflected by the optical deflector are located on the same side of the light path of the reflected light.

5. The optical scanning unit according to claim 1 , further comprising a lens disposed on a light path between the light source and the light deflector,
wherein the light shield is disposed between the lens and the light transmission window.

6. The optical scanning unit according to claim 5 , wherein the lens is a coupling lens, and the light shield is at least partly made of an opening member that includes an opening disposed on a light path of light between the coupling lens and the optical deflector to transmit a part of the light.

7. The optical scanning unit according to claim 1 , wherein the optical deflector further comprises:
a first holder that rotatably holds the mirror; and
a second holder that holds the light transmission window connected to the first holder.

8. The optical scanning unit according to claim 1 , wherein the mirror is rotatable within a first range around a first axis and a second range whose size is different from the first range around a second axis perpendicular to the first axis,
wherein the light path of the reflected light is deviated from a region on the surface in a scanning direction corresponding to one of the first axis and the second axis.

9. The optical scanning unit according to claim 1 , wherein the light source is a laser.

10. An apparatus, comprising at least one optical scanning unit according to claim 1 .

11. The apparatus according to claim 10 , further comprising a modulator to modulate light from the light source of the optical scanning unit based on the image data.

12. The apparatus according to claim 11 , further comprising a light transmission member that includes the surface, disposed on the light path of the light deflected by the optical deflector in the optical scanning unit.

13. A vehicle, comprising:
the apparatus according to claim 12 ; and
a light transmission window disposed on a light path that passes through the light transmission member after being deflected by the optical deflector in the apparatus.

14. The optical scanning unit according to claim 1 , wherein the light shield is an opening member that includes an opening disposed on a light path of light between the coupling lens and the optical deflector to transmit a part of the light.

15. The optical scanning unit according to claim 14 , wherein surroundings of the opening of the opening member are disposed on the light path of the reflected light.

16. The optical scanning unit according to claim 14 , wherein a part of the opening member is configured to be tilted.

Assignees

• Ichii Daisuke
• Ricoh Co Ltd

Inventors

• Ichii Daisuke

Classifications

• G02B26/0833 Primary

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• G02B26/0841 Primary

  the reflecting element being moved or deformed by electrostatic means · 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

• G02B27/0018

  with means for preventing ghost images (anti-reflection coatings G02B1/11) · CPC title

• G02B27/0101

  characterised by optical features (G02B27/0172 takes precedence) · CPC title