COMPLEMENTARY METAL-OXIDE SEMICONDUCTOR (CMOS) TIME DELAY INTEGRATION (TDI) SENSOR FOR X-RAY IMAGING APPLICATIONS

摘要

PROBLEM TO BE SOLVED: To provide an image sensor having a complementary metal-oxide semiconductor (CMOS) time delay integration (TDI) structure that is especially advantageous for implementing X-ray scanning detector systems requiring large pixel numbers and signal processing circuitry that is physically separated from the photodiode array for X-ray shielding.;SOLUTION: A CMOS TDI image sensor consists of M pixels where each pixel is formed by a column of N TDI stages. Each TDI stage contains a photodiode that collects photo-charge and a pre-amplifier that proportionally converts the photo-charge to a voltage. Each TDI stage also has a set of capacitors, amplifiers, and switches for storage of the integrated signal voltages, where correlated double sampling (CDS) technique maintains both photo-signal and reset voltages simultaneously (in an actual or pseudo manner). The CDS signal voltages can be passed from one TDI stage to the next TDI stage along a column for summing. The CDS signal voltages of the last TDI stages of M pixels are read out with a differential amplifier.;COPYRIGHT: (C)2012,JPO&INPIT