Two-Transistor Active Pixel Sensor for High Resolution Large Area Digital X-ray Imaging

A novel architecture for active pixel sensor (APS) arrays with only two thin film transistors (TFTs) is presented, and a new driving scheme for minimizing the threshold voltage metastability problem and increasing frame rate is discussed. The fewer number of on-pixel elements, and reduced pixel complexity, results in a smaller pixel pitch and increased pixel gain, and makes the presented APS architecture promising for high resolution, high speed imaging modalities such as digital mammography tomosynthesis.