A Time-of-Flight Range Image Sensor With Background Canceling Lock-in Pixels Based on Lateral Electric Field Charge Modulation

作者：Han Sang Man; Takasawa Taishi; Yasutomi Keita; Aoyama Satoshi; Kagawa Keiichiro; Kawahito Shoji^*

来源：IEEE Journal of the Electron Devices Society, 2015, 3(3): 267-275.

DOI：10.1109/JEDS.2014.2382689

• CMOS image sensor
• depth image
• pinned photodiode
• time-of-flight (ToF)
• lateral electric field charge modulator (LEFM)

This paper presents a CMOS time-of-flight (ToF) range image sensor using high-speed lock-in pixels with background light canceling capability. The proposed lock-in pixel uses MOS gate-induced lateral electric field control of depleted potential of pinned photodiode for implementing a multiple-tap charge modulator while achieving a high-speed charge transfer for high-time resolution. A TOF image sensor with 320 x 240 effective pixels is implemented using a 0.11-mu m CMOS image sensor process. The TOF sensor has a range resolution of less than 12 mm without background light and 20 mm under background line for the range from 0.8 to 1.8 m and integration time of 50 ms. The effectiveness of in-pixel background light canceling with a three-tap output pixel is demonstrated.

• 出版日期2015-5