Design and characterization of a 256 x 64-pixel single-photon imager in CMOS for a MEMS-based laser scanning time-of-flight sensor.
We introduce an optical time-of-flight image sensor taking advantage of a MEMS-based laser scanning device. Unlike previous approaches, our concept benefits from the high timing resolution and the digital signal flexibility of single-photon pixels in CMOS to allow for a nearly ideal cooperation between the image sensor and the scanning device. This technique enables a high signal-to-background light ratio to be obtained, while simultaneously relaxing the constraint on size of the MEMS mirror. These conditions are critical for devising practical and low-cost depth sensors intended to operate in uncontrolled environments, such as outdoors. A proof-of-concept prototype capable of operating in real-time was implemented. This paper focuses on the design and characterization of a 256 x 64-pixel image sensor, which also comprises an event-driven readout circuit, an array of 64 row-level high-throughput time-to-digital converters, and a 16 Gbit/s global readout circuit. Quantitative evaluation of the sensor under 2 klux of background light revealed a repeatability error of 13.5 cm throughout the distance range of 20 meters.
Applied Optics Lab, Toyota Central R&D Labs, Inc, 480-1192 Nagakute, Aichi, Japan. niclass@mosk.tytlabs.co.jp
Cristiano
C
Niclass
Kota
K
Ito
Mineki
M
Soga
Hiroyuki
H
Matsubara
Isao
I
Aoyagi
Satoru
S
Kato
Manabu
M
Kagami
D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D018613:Microscopy, Confocal / Q000295:instrumentation*; D008962:Models, Theoretical; D010783:Photometry / Q000295:instrumentation*; D012666:Semiconductors