CMOS image sensor with off-center circular apertures for depth extraction

Abstract

A CMOS image sensor with off-center circular apertures for two-dimensional (2D) and three-dimensional (3D) imaging was fabricated, and its performance was evaluated, including the results of 2D and 3D images. The pixel size, based on a four-transistor active pixel sensor with a pinned photodiode, is 2.8 mu m x 2.8 mu m. Disparate images as well as focused images for depth calculation can be obtained using the designed pixel pattern. The pixel pattern is composed of one white subpixel with a left-offset circular aperture, a blue pixel, a red pixel, and another white subpixel with a right-offset circular aperture. The proposed technique was verified by simulation and measurement results using a point light source. In addition, the depth image was implemented by calculating the depth information from the 2D images.