IP Library Granted Patent US 9,784,967
Granted Patent B2
US 9,784,967 · App. 14/977,511 · Granted Oct 10, 2017

Suppression of undesired harmonics in MEMS mirror projector display

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 9,784,967
App. No.
14/977,511
Granted
Oct 10, 2017
Kind
B2
Abstract

Disclosed herein are devices and methods to generate a drive signal to actuate a MEMS mirror system. A controller can generate the drive signal to comprise a modified square wave voltage waveform comprising a tri-stated portion, an attenuated portion, or a tri-stated and an attenuated portion to suppress a number of harmonics in a response of the MEMS mirror system to the drive signal.

Claims (68)

1. An apparatus, comprising:

a microelectromechanical system (MEMS) mirror system; and

a controller to generate a drive signal to actuate the MEMS mirror system, the controller to modify the drive signal to reduce at least one harmonic in a response of the MEMS mirror system to actuation by the drive signal.

2. The apparatus of claim 1 , the controller comprising:

a current source to generate a current; and

a switching assembly electrically coupled to the current source, the switching assembly to receive the current and to generate the drive signal based on the current.

3. The apparatus of claim 2 , wherein the drive signal is a periodic voltage waveform.

4. The apparatus of claim 3 , wherein the drive signal is a modified square wave voltage waveform.

5. The apparatus of claim 4 , the switching assembly to:

generate a square wave voltage waveform; and

attenuate at least a portion of the square wave voltage waveform to form the drive signal.

6. The apparatus of claim 4 , the switching assembly to:

generate a square wave voltage waveform; and

tri-state at least a portion of the square wave voltage waveform to form the drive signal.

7. The apparatus of claim 4 , the switching assembly to:

generate a square wave voltage waveform;

tri-state at least a first portion of the square wave voltage waveform;

attenuate at least a second portion of the square wave voltage waveform; and

output the tri-stated and attenuated voltage waveform as the drive signal.

8. The apparatus of claim 1 , the MEMS mirror system comprising:

a motor operably coupled to the controller; and

a mirror operably coupled to the motor.

9. The apparatus of claim 8 , the controller to apply the drive signal to the motor to actuate the motor to rotate the mirror about at least one axis.

10. The apparatus of claim 9 , wherein the mirror is a two-dimensional (2D) mirror to rotate about a first axis and a second axis different than the first axis.

11. A system comprising:

a microelectromechanical system (MEMS)mirror system;

a controller comprising:

a current source to generate a current; and

a switching assembly electrically coupled to the current source, the switching assembly to receive the current and to generate a drive signal to actuate the MEMS mirror system based on the current, the drive signal to reduce at least one harmonic in a response of the MEMS mirror system to actuation by the drive signal;

a light source optically coupled to the MEMS mirror system, the light source to emit light beams to be received by the MEMS mirror system; and

a projection surface optically coupled to the MEMS mirror system, the MEMS mirror to reflect and scan the light beams across the projection surface in response to actuation by the drive signal.

12. The system of claim 11 , wherein the drive signal is a modified square wave voltage waveform.

13. The system of claim 12 , the switching assembly to:

generate a square wave voltage waveform; and

attenuate at least a portion of the square wave voltage waveform to form the drive signal.

14. The system of claim 12 , the switching assembly to:

generate a square wave voltage waveform; and

tri-state at least a portion of the square wave voltage waveform to form the drive signal.

15. The system of claim 12 , the switching assembly to:

generate a square wave voltage waveform;

tri-state at least a first portion of the square wave voltage waveform;

attenuate at least a second portion of the square wave voltage waveform; and

output the tri-stated and attenuated voltage waveform as the drive signal.

16. The system of claim 11 , comprising a heads up display (HUD) frame, the HUD frame coupled to the MEMS mirror system, the controller, the light source, and the projection surface.

17. The system of claim 16 , wherein the HUD frame is a glasses frame, a goggles frame, or a helmet frame.

18. A method comprising:

providing an electric current;

periodically switching the electric current to generate a drive signal to actuate a microelectromechanical system (MEMS) mirror system; and

modifying the drive signal to reduce at least one harmonic in a response of the MEMS mirror system to actuation by the drive signal.

19. The method of claim 18 , wherein the drive signal is a modified square wave voltage waveform.

20. The method of claim 18 , comprising:

generating a square wave voltage waveform;

modifying the square wave voltage waveform based at least in part on one or more of tri-stating or attenuating a portion of the square wave voltage waveform;

outputting the modified square wave voltage waveform as the drive signal.

21. An apparatus comprising:

a current source to generate an electric current;

a switching assembly electrically coupled to the current source, the switching assembly to:

receive the electric current

generate a periodic voltage waveform based on the electric current; and

modify the periodic voltage waveform to generate a drive signal to reduce at least one harmonic in a response of a microelectromechanical system (MEMS) mirror system to actuation by the drive signal; and

an output port electrically coupled to the switching assembly, the output port to receive the drive signal and to apply the drive signal to the MEMS mirror system to actuate the MEMS mirror system.

22. The apparatus of claim 21 , wherein the drive signal is a modified square wave voltage waveform.

23. The apparatus of claim 21 , the switching assembly to attenuate at least a portion of the periodic voltage waveform to form the drive signal.

24. The apparatus of claim 21 , the switching assembly to tri-state at least a portion of the periodic voltage waveform to form the drive signal.

25. The apparatus of claim 21 , the switching assembly to:

tri-state at least a first portion of the periodic voltage waveform;

attenuate at least a second portion of the periodic voltage waveform; and

output the tri-stated and attenuated periodic voltage waveform as the drive signal.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 19, 2020
From: NORTH INC.
To: GOOGLE LLC
Reel/Frame 054113/0744 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 22, 2019
From: INTEL CORPORATION
To: NORTH INC.
Reel/Frame 048106/0747 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 20, 2016
From: MCGLEW, PATRICK GERARD
To: INTEL CORPORATION
Reel/Frame 039791/0178 →