US Patent 7764279 Pixle circuit system for a light emitting display

A pixel circuit for driving a plurality of pixel units within a display includes: a plurality of scanning lines formed within the display for transmitting scanning signals to the pixel units; a plurality of data lines formed within the display and transversely crossing the scanning lines for transmitting data signals to the pixel units, respectively; and a plurality of LDD-TFTs. The LDD-TFT is coupled to a respective scanning line, a respective data line and a driving transistor. The LDD-TFT includes a first lightly doped drain that is closest to the driving transistor and that has a first length, and a second lightly doped drain that has a second length shorter than the first length.