Research And Design Of CMOS-TDI Imaging And Testing System

Line-scan image sensor uses a one-dimension pixel array to capture 2D image in a scaning method. Image quality is limited by illumination and speed of movement. TDI (Time-Delay Integration) image sensor is an advanced type of line-scan image sensor which uses a 2D pixel array to delay and accumulate the signal derived from every single scaning line. This is useful when it comes to critical situation where illumination level is extremely low or where the relative speed of movement is very fast. The signals delivered by the pixels are, in the case of TDI, adequately delayed and added simultaneously with the optical scanning, increasing the overall SNR performance as a result.Image sensor manufacturing generally adopts either CCD or CMOS technology. TDI functionality is typically implemented with CCD sensors. However, there are important reasons to implement TDI functionality in CMOS sensors because of the potential advantages of process accessibility, additional circuit functionality on-chip, robustness to ionizing radiation, reduced cost, lower power comsumption, simpler system design, etc. TDI products are seldom reported due to confidentiality issues, let along CMOS-TDI ones. The development of a CMOS-TDI imaging and testing system has become a significant part of the development of CMOS-TDI sensors.This paper presents a design and implementation of CMOS-TDI imaging and testing system, focusing on modeling and key technology of system design, which includes circuit, hardware and software design. The system implemented provides the required environment by TDI functionality, serves as test bench of pixel design as well as verification platform of the algorithm and RTL model of ISP blocks. Works in this paper is indispensable to the development of CMOS-TDI image sensors.