MEMS mirror device with reduced static reflection

Patent metadata

Field	Value
Publication number	US-11573295-B2
Application number	US-201916410899-A
Country	US
Kind code	B2
Filing date	May 13, 2019
Priority date	May 13, 2019
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

Methods and systems for using a MEMS mirror for steering a LiDAR beam and for minimizing statically emitted light from a LiDAR system are disclosed. A LiDAR system includes a light source that emits a light beam directed at a MEMS device. The MEMS device includes a manipulable mirror that reflects the emitted light beam in a scanning pattern. The MEMS device also includes a substrate positioned adjacent to and at least partially surrounding the mirror. An attenuation layer is disposed on a top surface of the substrate and is configured to attenuate light reflected by the substrate.

First claim

What is claimed is:

1. A LiDAR system comprising:
a light source positioned within the LiDAR system that emits a light beam directed at a MEMS device, wherein the MEMS device includes:
a manipulable mirror that reflects the emitted light beam through an aperture of the LiDAR system and steers the reflected light beam in a scanning pattern outside of the LiDAR system;
a substrate positioned adjacent to and at least partially surrounding the mirror;
an attenuation system comprising a transparent thin film structure with alternating layers having a contrasting refractive index disposed on a top surface of the substrate that attenuates an intensity of a reflection of the emitted light beam from the attenuation system that exits the aperture; and

a receiver that receives light reflected off an object outside of the LiDAR system.

2. The LiDAR system of claim 1 wherein the light beam includes a center portion that is reflected by the manipulable mirror and a tail portion that surrounds the center portion and is reflected by the attenuation system.

3. The LiDAR system of claim 1 wherein the attenuation system comprises an anti-reflective coating.

4. The LiDAR system of claim 1 wherein the mirror has an oval shape.

5. The LiDAR system of claim 1 wherein the attenuation system comprises a diffraction grating.

6. The LiDAR system of claim 1 wherein the attenuation system comprises a diffuse reflection coating.

7. The LiDAR system of claim 1 wherein the attenuation system comprises an absorbing coating.

8. A micro-electromechanical system (MEMS) package comprising:
a manipulable mirror having a reflective surface;
a substrate positioned adjacent to and at least partially surrounding the mirror; and
an attenuation system comprising a transparent thin film structure with alternating layers having a contrasting refractive index disposed on the substrate and configured to attenuate an intensity of reflected light.

9. The MEMS package of claim 8 configured to receive a light beam including a center portion and a tail portion that surrounds the center portion;
wherein the center portion of the light beam is reflected by the mirror; and
wherein the attenuation system attenuates an intensity of the tail portion that is reflected by the attenuation system.

10. The MEMS package of claim 8 wherein the attenuation system comprises an anti-reflective coating.

11. The MEMS package of claim 8 wherein the mirror has an oval shape.

12. The MEMS package of claim 8 wherein the attenuation system comprises a diffraction grating.

13. The MEMS package of claim 8 wherein the attenuation system comprises a diffuse reflection coating.

14. The MEMS package of claim 8 wherein the attenuation system comprises an absorbing coating.

15. A method of using a micro-electromechanical system (MEMS) package comprising:
receiving a light beam through a window of the MEMS package, wherein the light beam has a center portion and a tail portion that surrounds the center portion;
steering a reflection of the center portion of the light beam by reflecting the center portion of the light beam off a mirror, wherein the mirror is positioned adjacent to a substrate; and
attenuating a reflection of the tail portion of the light beam that is reflected off the substrate using an attenuation system comprising a transparent thin film structure with alternating layers having a contrasting refractive index disposed on a top surface of the substrate.

16. The method of claim 15 wherein the attenuation system comprises an anti-reflective coating.

17. The method of claim 15 wherein the mirror has an oval shape.

18. The method of claim 15 wherein the attenuation system comprises a diffraction grating.

19. The method of claim 15 wherein the attenuation system comprises a diffuse reflection coating.

20. The method of claim 15 wherein the attenuation system comprises an absorbing coating.

Assignees

• Beijing Voyager Tech Co Ltd

Inventors

• Lee Sae Won
• Wang Youmin
• Zhou Qin

Classifications

• G02B26/0833

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

• G01S7/4814

  of transmitters alone · CPC title

• G02B1/11

  Anti-reflection coatings · CPC title

• G01S7/4817 Primary

  relating to scanning · CPC title

• G01S17/931

  of land vehicles · CPC title