Compact line scan MEMS time of flight system with actuated lens

Patent metadata

Field	Value
Publication number	US-12164103-B2
Application number	US-202117533890-A
Country	US
Kind code	B2
Filing date	Nov 23, 2021
Priority date	Dec 16, 2020
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

Disclosed herein is an optical module including a substrate, with an optical detector, laser emitter, and support structure being carried by the substrate. An optical layer includes a fixed portion carried by the support structure, a movable portion affixed between opposite sides of the fixed portion by a spring structure, and a lens system carried by the movable portion. The movable portion has at least one opening defined therein across which the lens system extends, with at least one supporting portion extending across the at least one opening to support the lens system. The optical layer further includes a MEMS actuator for in-plane movement of the movable portion with respect to the fixed portion.

First claim

The invention claimed is:

1. An optical module, comprising:
a substrate;
an optical detector carried by the substrate;
a laser emitter carried by the substrate;
a support structure carried by the substrate; and
an optical layer comprising:
a fixed portion carried by the support structure;
a movable portion affixed between opposite sides of the fixed portion by a spring structure;
a lens system carried by the movable portion;
wherein the movable portion has at least one opening defined therein across which the lens system extends, with at least one supporting portion extending across the at least one opening to support the lens system; and
a MEMS actuator for in-plane movement of the movable portion with respect to the fixed portion.

2. The optical module of claim 1 , wherein the at least one supporting portion extends parallel to an axis of movement of the movable portion.

3. The optical module of claim 1 , wherein the at least one supporting portion comprises a plurality of supporting portions.

4. The optical module of claim 3 , wherein the plurality of supporting portions include at least some supporting portions extending parallel to an axis of movement of the movable portion.

5. The optical module of claim 4 , wherein the plurality of supporting portions include at least some other supporting portions extending perpendicular to an axis of the movement of the movable portion.

6. The optical module of claim 3 , wherein the plurality of supporting portions include at least some supporting portions extending antiparallel to an axis of movement of the movable portion.

7. The optical module of claim 3 , wherein the plurality of supporting portions include at least some supporting portions extending elliptically about a central point of the lens system.

8. The optical module of claim 1 , wherein the MEMS actuator comprises:
a comb drive comprising:
a first comb structure extending from the fixed portion to interdigitate with a second comb structure extending from the movable portion; and
actuation circuitry configured to apply voltages to the first and second comb structures to cause the movable portion of the optical layer to oscillate back and forth between opposite sides of the fixed portion such that at a first travel limit the movable portion of the optical layer is closer to the a first side of the fixed portion than to a second side of the fixed portion, and such that at a second travel limit the movable portion of the optical layer is closer to the second side of the fixed portion than to the first side of the fixed portion.

9. The optical module of claim 1 , wherein the MEMS actuator comprises:
a first comb structure extending from a first side of the fixed portion to interdigitate with a second comb structure extending from an adjacent side of the movable portion;
a third comb structure extending from a second side of the fixed portion to interdigitate with a fourth comb structure extending from an adjacent side of the movable portion; and
actuation circuitry configured to apply voltages to the first, second, third, and fourth comb structures to cause the movable portion of the optical layer to oscillate back and forth between opposite sides of the fixed portion such that at a first travel limit the movable portion of the optical layer is closer to a first side of the fixed portion than to a second side of the fixed portion, and such that at a second travel limit the movable portion of the optical layer is closer to the second side of the fixed portion than to the first side of the fixed portion.

10. The optical module of claim 1 , wherein the spring structure is a MEMS spring structure.

11. The optical module of claim 1 , wherein the fixed portion, movable portion, at least one supporting portion, and spring structure are integrally formed as a monolithic unit.

12. The optical module of claim 1 , further comprising an encapsulating layer carried by the fixed portion and overlying the lens system.

13. The optical module of claim 1 , wherein the lens system comprises a metasurface optic.

14. The optical module of claim 1 , wherein the lens system is comprised of an objective lens and a beam shaping lens spaced apart from the objective lens.

15. The optical module of claim 1 , wherein the movable portion is comprised of a shuttle carrying the lens system, with the spring structure comprising first, second, third, and fourth flexures respective extending from different corners of the shuttle to anchor at different corners of the fixed portion.

16. The optical module of claim 15 , wherein the first, second, third, and fourth flexures are S-shaped.

17. The optical module of claim 15 , wherein the shuttle is comprised of a first shuttle portion carrying an objective lens portion of the lens system, a second shuttle portion carrying a beam shaping lens portion of the lens system, and a connector portion extending between the first and second shuttle portions, a width of the connector portion being less than a width of the first and second shuttle portions.

18. The optical module of claim 17 , wherein the shuttle has first and second openings defined therein over which the objective lens portion and the beam shaping lens portion are disposed.

19. The optical module of claim 15 , wherein the shuttle is comprised of first and second spaced apart shuttle portions.

20. The optical module of claim 1 , further comprising an additional glass substrate carried by the support structure, the additional glass substrate carrying the optical layer.

21. An optical module, comprising:
a substrate;
an optical circuit carried by the substrate; and
an optical layer comprising:
a fixed portion carried by the substrate;
a movable portion affixed between opposite sides of the fixed portion by a spring structure;
a lens system carried by the movable portion, the lens system being aligned with the optical circuit;
wherein the movable portion has at least one opening defined therein across which the lens system extends, with at least one supporting portion extending across the at least one opening to support the lens system;
a comb drive formed by respective features of the fixed portion and movable portion; and
actuation circuitry configured to apply a drive signal to the comb drive to thereby cause electrostatic actuation to the comb drive resulting in the movable portion of the optical layer oscillating back and forth between opposite sides of the fixed portion.

22. The optical module of claim 21 , wherein the at least one supporting portion extends parallel to an axis of movement of the movable portion.

23. The optical module of claim 21 , wherein the at least one supporting portion comprises a plurality of supporting portions.

24. The optical module of claim 23 , wherein the plurality of supporting portions include at least some supporting portions extending parallel to an axis of movement of the movable portion.

25. The optical module of claim 24 , wherein the plurality of supporting portions include at least some other supporting portions extending perpendicular to an axis of the movement of the movable portion.

Assignees

• St Microelectronics Res & Dev Ltd
• St Microelectronics Srl
• Stmicroelectronics Res &Develoment Limited

Inventors

• Townsend Christopher
• Carminati Roberto

Classifications

• B81B2201/033

  Comb drives · CPC title

• B81B3/0021

  Transducers for transforming electrical into mechanical energy or vice versa (dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00) · CPC title

• G01S17/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01S7/4817

  relating to scanning · CPC title

• G01S17/89

  for mapping or imaging · CPC title