CMOS image sensor using pixel aperture technique for single-chip 2D and 3D imaging

This paper presents a CMOS image sensor that uses the pixel aperture technique for extracting depth information while producing conventional 2D images. In conventional image sensors, the aperture is located at the camera lens. However, in the proposed image sensor, the aperture is integrated on the CMOS image sensor chip and is formed at a metal layer of the CMOS process. The pixel array of the proposed image sensor, used for extracting color and depth information, is composed of four different types of pixels — white pixels with aperture, blue pixels, green pixels, and white pixels without aperture. The size of the pixel, which is based on a four-transistor active pixel sensor with pinned photodiode, is 2.8 μm × 2.8 μm. A prototype of the proposed image sensor was fabricated using the 0.11 μm CMOS image sensor process, and the feasibility of the pixel aperture technique was verified.