MEMS-Driver Laser Beam Scanning LiDAR: The Future of Variable Spatial Resolution Sensing and Foveated Ranging , The 7th Laser Display and Lighting Conference 2018 (LDC'18), Yokohama, Japan, Apr. 24-27, 2018

1. Don’t just think outside the box.
See outside the box.
MEMS-Driven Laser Beam Scanning LiDAR:
The Future of Variable Spatial Resolution Sensing and Foveated Ranging
LDC2-2, LDC 2018, Yokohama, Japan, April 24, 2018
Jari Honkanen
(Jari_Honkanen@MicroVision.com)
(https://www.linkedin.com/in/jarihonkanen)

2. 2 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
MEMS-Driven Laser Beam Scanning:
One Platform, Multiple Applications

3. MEMS-Driven
Laser Beam Scanning (LBS)
Technology

4. 4 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
SLOW SCAN AXIS
(Vertical）
FAST SCAN AXIS
(Horizontal）
MEMS = Micro Electro Mechanical System
Coil
Mirror
Φ1.2mm
PicoP® Laser Beam Scanning - MEMS

5. 5 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
Laser Beam
PicoP® Laser Beam Steering

6. 6 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
MICROVISION, INC. COPYRIGHT 2013. ALL RIGHTS RESERVED.
Vertical Trajectory:
Drive vs. Time
Generation of Raster Pattern
Horizontal Trajectory: Drive vs. Time
Single drive input contains both
Slow Scan Ramp and Fast Scan
Sinusoidal drive signals
PicoP® Laser Beam Scanning – MEMS Actuation

7. 3D Depth Sensing
and
LiDAR

8. 8 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
3D Depth Sensor – what is it?
 3D sensors allow devices to observe the
environment in 3 dimensions
 3D imagers measure distance for every pixel
within detection field.
Number of
measurements
within detection
field of view
Depth
Sensor/Imager
X
Y
Distance,
Z
Depth Map Point Cloud
 3D imagers produce a 2D addressable array, a
depth map, or further a 3-dimensional collection
of points, a point cloud

9. 9 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
2D MEMS
Mirror
IR laser
IR Photodetector
MEMS-Driven Laser Beam Scanning LiDAR 3D Sensor
• X,Y location of object known because of knowledge
of MEMS pointing angle. No computation required.
• Z determined by Time-of-Flight: Z = ½ * c * tTOF
IR Photodetector can be:
• PIN Photodiode
• Silicon Photomultiplier (SiPM)
• Avalanche Photodiode (APD)

10. 10 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
3D Depth Sensing Key Performance Metrics
zmeasured
zactual
Δz
y (#rows)
V◦
H◦ zmeasured
zactual
Metric Symbol Measure
Spatial Resolution x * y # of points
Field of View H◦ * V◦ degrees
Angular Resolution h◦=H◦/x * v◦=V◦/y degrees
Range z distance
Frame Rate fps # per second
Precision Δz % deviation
Accuracy |zmeasured – zactual| % error

11. MEMS-Driven LBS LiDAR
Performance Controls

12. 12 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
MEMS-Driven LBS LiDAR Performance Controls
Metric Symbol Measure
Spatial Resolution x * y # of points
Field of View H◦ * V◦ degrees
Angular Resolution h◦=H◦/x * v◦=V◦/y degrees
Range z distance
Frame Rate fps # per second
Precision Δz % deviation
Accuracy |zmeasured – zactual| % error
Variable, Dynamically Programmable
Variable, Dynamically Programmable

13. 13 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
time
y 2 * y
Vertical Resolution vs. Frame Rate
Vertical Trajectory (Frame Rate)
Vertical Resolution

14. 14 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
IR laser
Dynamic Programmable Resolution and Frame Rate
IR Photodetector
IR laser
IR Photodetector
IR laser
IR Photodetector
128×720 @60Hz 256×720 @30Hz 384×720 @20HzReturn delay +
Analog chain
relaxation time

15. 15 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
time
Δv1
◦ Δv2
◦
Vertical Angular Resolution vs. Field of View
Vertical Scan Angle (Field of View)
Vertical Angular Resolution
V1
◦ V2
◦

16. 16 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
Δh◦
H1◦
Δh◦
H2◦
Horizontal Angular Resolution vs. Field of View
Horizontal Scan Angle (Field of View)
Horizontal Angular Resolution

17. 17 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
Uniform laser pulse positioning
Staggered laser pulse positioning
Horizontal Resolution vs. Vertical Resolution
128×720 @60Hz
512×180 @60Hz

18. 18 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
time
Uniform scan line spacing
& vertical resolution
Variable scan line spacing
& vertical resolution
Dynamic 1D Foveated Ranging
Vertical Trajectory

19. 19 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
1 2 3
1 2 3
Optical bandpass filter
(Each PD sensitive to 1 λ)
MEMS-Driven LBS High-Definition LiDAR
IR Laser Diodes
2D MEMS
Example IR λs:
830 nm, 885 nm, 940 nm
IR Photodiodes
Detect
2048×1080 @ 7.5Hz
384×720 @ 60Hz

20. 20 MICROVISION, INC. COPYRIGHT 2018. ALL RIGHTS RESERVED.1/21/2020
Conclusion: MEMS-Driven Scanning LiDAR Benefits
Cost Effective
(Re-uses mature LBS
technology)
Enables use of multiple
and redundant sensors
High
Resolution
(~5.5M – 16.5M
points/sec)
Ability to resolve small
features
Small Size
(Thin)
Enables new class of
form factors
Dynamic
(Programmable
Resolution and Frame
Rate)
Adapt latency and
fidelity to the
application or use case

21. DON’T JUST THINK OUTSIDE THE BOX.
SEE OUTSIDE THE BOX.
© 2018 MICROVISION, INC. ALL RIGHTS RESERVED.
PICOP IS A REGISTERED TRADEMARK OF MICROVISION, INC. ALL OTHER TRADEMARKS ARE
THE PROPERTY OF THEIR RESPECTIVE OWNERS.