Title
7.1 A 4-tap 3.5 μm 1.2 Mpixel Indirect Time-of-Flight CMOS Image Sensor with Peak Current Mitigation and Multi-User Interference Cancellation
Abstract
The evolution of 3D depth-sensing technology enables various applications in mobile devices, from conventional photography enhancement (e.g., autofocus and bokeh effect) to new applications such as augmented reality and 3D scanning. Usually, 3D depth sensors operate with RGB color sensors for image fusion; the spatial resolution of depth sensors should be compatible to that of RGB sensors for better image fusion quality, which requires mega-pixel depth sensors. Among different depth-sensing techniques, only indirect time-of-flight (ToF) sensors can generate higher resolution depth maps with smaller system cost and power [1,2]. Recent indirect ToF sensors have achieved continuous improvements in depth performance [1-4]. However, one of the issues with indirect ToF sensors is peak current during exposure time [1,2]. To solve the issue, current spreading can be adopted by driving each column group in a different time point; the resulting column fixed-pattern phase noise (FPPN) is compensated by time-interleaving two opposite-directional delay chains [2]. However, this approach suffers from demodulation contrast (DC) degradation around the edge of the pixel array, by combining two different phase signals at the pixel level [2]. Another issue for indirect ToF sensors is multi-user interference [5]. When multiple ToF cameras with the same modulation frequency shine light onto the same object, the reflected light signals interfere each other, which may distort depth information. In this work, a mega-pixel indirect ToF sensor is reported with the solutions for the two issues: 1) peak current mitigation with minimal side-effect, and 2) multi-user interference cancellation.
Year
DOI
Venue
2021
10.1109/ISSCC42613.2021.9365854
2021 IEEE International Solid- State Circuits Conference (ISSCC)
Keywords
DocType
Volume
indirect time-of-flight CMOS image sensor,peak current mitigation,multiuser interference cancellation,3D depth-sensing technology,conventional photography enhancement,RGB color sensors,RGB sensors,image fusion quality,mega-pixel depth sensors,different depth-sensing techniques,time-of-flight sensors,higher resolution depth maps,recent indirect ToF sensors,depth performance,exposure time,current spreading,different time point,resulting column fixed-pattern phase noise,time-interleaving,different phase signals,multiple ToF cameras,depth information,mega-pixel indirect ToF sensor,size 3.5 mum
Conference
64
ISSN
ISBN
Citations 
0193-6530
978-1-7281-9550-6
0
PageRank 
References 
Authors
0.34
0
22
Name
Order
Citations
PageRank
Min-Sun Keel131.08
Daeyun Kim2142.73
Yeo Myung Kim3182.46
Myunghan Bae451.46
Myoungoh Ki551.46
Bumsik Chung651.46
Sooho Son751.46
Hoyong Lee821.39
Heeyoung Jo900.34
Seung C. Shin1061.82
Sunjoo Hong1151.82
Jaeil An1200.34
Yonghun Kwon1351.46
Sungyoung Seo1451.46
Sunghyuck Cho1520.71
Youngchan Kim1651.80
Young-Gu Jin1751.46
youngsun oh1831.74
Yitae Kim1931.74
JungChak Ahn2043.11
Kyoungmin Koh2101.01
Yongin Park2201.69