Pixel Circuits for OLED Displays

The structures, operating principles and technical issues of OLED pixel circuits are explained in this chapter. First, the necessity and role of the OLED pixel circuit is introduced. Then, three operating principles: diode-connection, source-follower and current programming schemes of in-pixel compensation techniques are explained. Other compensation techniques utilizing a complicated system outside the display panel are also introduced. Moreover, three examples of OLED pixel circuits employed in mobile display products are analysed in detail. Finally, the effect of the VT extraction time and dimming method on low-grey-level mura, is discussed.