In this paper, we present a 55" UHD AMOLED TV developed at G8.5 using IGZO backplane and tandem white-OLED with COA (color filter on array), which is considered as one of the feasible options for mass production. We also implement the external optical compensation to achieve good display uniformity.

In order to compensate the threshold voltage variation while obtaining the sufficient data charging time, the AMOLED compensative pixel circuit needs to be driven by multi-pulse signals which have continuous high/low level pulses. By using traditional gate driver on array (GOA) with half duty-cycle delay of clock signals, the area of shift register is doubled, increasing the bezel width and power consumptions. In this paper, novel compact integrated gate driver circuit architectures for AMOLED pixel compensation purpose are presented. Outputs with programmable pulse width and number are achieved in these gate driving circuits without consuming extra large areas. Inner feedback technique is adopted in GOA circuit for leakage current cutting of depletion mode IGZO TFTs. The simulation result shows that these circuits work successfully with maximum ±3V threshold voltage shift. These GOA circuits can be used for internal or external Vth compensation techniques of AMOLED panel.

A new method for Sense and Calculate TFT characteristics is simulated with 3T1C structure of AMOLED display. By using data programming compensation, it can correct both Vth and Mobility. The proposed method uses Linear Charging Method which has faster charging speed than Source Follower Method. By increasing the Vgs of driving TFT, we can even reduce the charging time to 0.5ms. And fast charging make it possible to achieve real‐time detection in higher and higher resolution display. The principle of the method will be described in detail and giving out the simulation data. The experiments are carried out in a 31‐inch AMOLED panel.

A 17‐inch full‐color active matrix organic light‐emitting diode (AMOLED) display has been developed, which combine with amorphous indium‐gallium‐zinc oxide (IGZO) thin film transistors and ink‐jet printing technology. It was also proved that ink‐jet printing technology can be used for large size AMOLED panel fabrication on IGZO thin film transistor backplane.

A novel gate driver on array (GOA) circuit topology based on pulse width modulation (PWM) technique has been proposed for internal compensation AMOLED pixel driving. The output width of PWM GOA basic unit can be easily adjusted by tuning start pulse (STU) signal width. The performance of this circuit has been verified by simulation and the prototype has been fabricated in 5 inch AMOLED panel with IGZO TFT process. There are three main features of PWM GOA circuit, (1) PWM GOA is properly designed with depletion mode IGZO TFTs (2) Output pulse width can be easily changed by tuning STU's width without additional circuits (3) Interface and accessory of PWM GOA is custom designed to realize different function of each block. ThisGOA structure provides a practical way to realize narrow bezel design.