A 1920×1080 3.65μm-pixel 2D/3D image sensor with split and binning pixel structure in 0.11pm standard CMOS

Abstract

Real-time capturing of a color image and depth map from an arbitrary scene is very crucial in various applications such as robotics, automotive, augmented reality, and interactive gaming, because it enables electronic devices to recognize and track target objects without complicated post-processing. Numerous color image sensors have been developed, pushing small-size and high-sensitivity pixels [1,2]; likewise, time-of-flight (ToF) depth imagers, where pixels directly provide their own depth information, have been presented based on single-photon avalanche diodes (SPADs) [3] and photo-mixing devices [4]. However, it is still challenging to implement a single image sensor that can simultaneously acquire color and depth images. This is because the principles of operation for acquisition of both types of images are totally different, resulting in a difference in detector devices and pixel sizes (1.4μm color vs. 40μm depth in commercial products). To address this problem, a CMOS image sensor with typical pinned-photodiode and multi-resolution functionality was recently demonstrated [5]. The paper shows that a conventional pinned-photodiode can demodulate a ToF signal at 10MHz frequency.