Mirror assembly for light steering

Patent metadata

Field	Value
Publication number	US-2020182977-A1
Application number	US-201816237454-A
Country	US
Kind code	A1
Filing date	Dec 31, 2018
Priority date	Dec 7, 2018
Publication date	Jun 11, 2020
Grant date	—

Abstract

Embodiments of the disclosure provide an apparatus for adjusting a light beam that includes a microelectromechanical system (MEMS), a non-MEMS system. The MEMS may include: an array of first rotatable mirrors to receive and reflect the light beam and an array of first actuators configured to rotate each rotatable mirror of the array of first rotatable mirrors. The non-MEMS system may include a second adjustable mirror to receive and reflect the light beam and a second actuator configured to adjust the second adjustable mirror. The light beam received by the array of first rotatable mirrors is the light beam reflected by the second adjustable mirror or the light beam received by the second adjustable mirror is reflected by the array of first rotatable mirror.

First claim

What is claimed is:

1 . An apparatus for adjusting a light beam, comprising:
a microelectromechanical system (MEMS), comprising:
an array of first rotatable mirrors configured to receive and reflect the light beam; and
an array of first actuators configured to rotate each rotatable mirror of the array of first rotatable mirrors; and
a non-MEMS system, comprising:
a second adjustable mirror configured to receive and reflect the light beam; and
a second actuator configured to adjust the second adjustable mirror; and
wherein the light beam received by the array of first rotatable mirrors is the light beam reflected by the second adjustable mirror, or the light beam received by the second adjustable mirror is reflected by the array of first rotatable mirror.

2 . The apparatus of claim 1 , wherein the array of first rotatable mirrors and the second adjustable mirror are configured to set a first angle of light path of the light beam with respect to a first dimension and to set a second angle of the light path of the light beam with respect to a second dimension orthogonal to the first dimension respectively.

3 . The apparatus of claim 2 , wherein the apparatus further comprises a controller, and wherein the controller is configured to:
control the array of the first actuators and the second actuator to output a first light including a first light signal at a first time point along the light path towards an object; control the array of the first actuators and the second actuator to select a second light including a second light signal propagating along the light path from the object; receive, via a receiver, the second light at a second time point; and determine a location of the object with respect to the apparatus based on a difference between the first time point and the second time point, the first angle, and the second angle.

4 . The apparatus of claim 1 , wherein the non-MEMS system is an analog system including at least one of a galvanometer mirror, a mirror polygon, or a flash lens.

5 . The apparatus of claim 4 , further comprising a third mirror facing the array of first rotatable mirrors and the second adjustable mirror and is configured to reflect the light beam reflected from the array of first rotatable mirrors towards the second adjustable mirror.

6 . The apparatus of claim 5 , further comprising a semiconductor substrate, wherein the third mirror is separated from the surface of the semiconductor substrate by a first distance;
wherein the array of the first rotatable mirrors and the second adjustable mirror are separated by a second distance; and wherein the first distance and the second distance are set based on an angle of incidence of the light beam from a light source with respect to the first rotatable mirror.

7 . The apparatus of claim 6 , further comprising a collimator lens, wherein the collimator lens is positioned between the light source and the first rotatable mirror, and wherein the collimator lens has a pre-determined aperture length.

8 . The apparatus of claim 7 , wherein the light source is a laser diode.

9 . The apparatus of claim 1 , wherein each actuator of the array of first actuators comprises at least one of a comb drive, a piezoelectric device, or an electromagnetic device.

10 . The apparatus of claim 1 , wherein the controller is further configured to:
adjust a first rotation angle of each rotatable mirror of the array of first rotatable mirrors at a first frequency, the first frequency being substantially equal to a natural frequency of the array of first rotatable mirrors; and adjust a second rotation angle of the second adjustable mirror at a second frequency lower than the first frequency.

11 . A Light Detection and Ranging (LiDAR) system comprising:
a light source; a receiver; a microelectromechanical system (MEMS) comprising:
an array of first rotatable mirrors to receive and reflect the light beam; and
an array of first actuators configured to rotate each rotatable mirror of the array of first rotatable mirrors; and
a non-MEMS system comprising:
a second adjustable mirror to receive and reflect the light beam; and
a second actuator configured to adjust the second adjustable mirror; and

wherein, the light beam received by the array of first rotatable mirrors is the light beam reflected by the second adjustable mirror or the light beam received by the second adjustable mirror is reflected by the array of first rotatable mirror.

12 . The system of claim 11 , wherein the array of first rotatable mirrors and the second adjustable mirror are configured to set a first angle of light path of the light beam with respect to a first dimension and to set a second angle of the light path of the light beam with respect to a second dimension orthogonal to the first dimension respectively.

13 . The system of claim 12 , wherein the system further comprises a controller, and wherein the controller is configured to:
control the array of the first actuators and the second actuator to output a first light including a first light signal at a first time point along the light path towards an object; control the array of the first actuators and the second actuator to select a second light including a second light signal propagating along the light path from the object; receive, via a receiver, the second light at a second time point; and determine a location of the object with respect to the apparatus based on a difference between the first time point and the second time point, the first angle, and the second angle.

14 . The system of claim 11 , wherein the non-MEMS system is an analog system including at least one of a galvanometer mirror, a polygon mirror or a flash lens.

15 . The system of claim 14 , further comprising a third mirror facing the array of first rotatable mirrors and the second adjustable mirror and is configured to reflect the light beam reflected from the array of first rotatable mirrors towards the second adjustable mirror.

16 . The system of claim 15 , wherein the third mirror is separated from the surface of the semiconductor substrate by a first distance;
wherein the array of the first rotatable mirrors and the second adjustable mirror are separated by a second distance; and wherein the first distance and the second distance are set based on an angle of incidence of the light beam from a light source with respect to the first rotatable mirror.

17 . The system of claim 16 , further comprising a collimator lens, wherein the collimator lens is positioned between the light source and the first rotatable mirror, and wherein the collimator lens has a pre-determined aperture length.

18 . The system of claim 11 , wherein the light source is a laser diode.

19 . The system of claim 11 , wherein each actuator of the array of first actuators comprises at least one of: a comb drive, a piezoelectric device, or an electromagnetic device.

20 . A method for adjusting a light beam in a light steering system, comprising:
determining a first angle and a second angle of a light path, the light path being a projection path for an output light or an input path of an input light, the first angle being with respect to a first dimension, the second angle being with respect to a second dimension orthogonal to the first dimension; controlling an array of first actuators to rotate an array of first rotatable micro-mirrors of a microelectromechanical system (MEMS) to set the first angle; controlling a non-MEMS system to set

Assignees

• Didi Res America Llc

Inventors

• Wang Youmin
• Kong Lingkai

Classifications

• G02B26/121

  Mechanical drive devices for polygonal mirrors · CPC title

• 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

• G02B26/105

  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

• G01S7/4817 Primary

  relating to scanning · CPC title