32.2: An Innovative Pixel‐Driving Scheme for 64‐Level Gray‐Scale Full‐Color Active Matrix OLED Displays

Abstract

Innovative pixel driving for active matrix OLED displays is described. A full-color display with a luminous deviation of less than 1.6%, which means a 6-bit or 64-level gray-scale accuracy, is shown. The driving is preferable for full-color video with gamma correction.

Reducing image sticking in AMOLED displays with time‐ratio gray scale by analog calibration

“…Various driving methods and pixel circuits have been developed to overcome the sensitivity of the OLED current to the I-V characteristic of the driving TFT. [2][3][4][5][6][7][8][9][10][11][12][13] Among them, a time-ratio gray-scale method with a simple pixel circuit comprised of two transistors and a storage capacitor, is known to give excellent image uniformity. 14,15 In this method, a gray level is produced by turning the OLED in each pixel on or off during each of multiple subframe periods.…”

OLED Displays on Plastic

“…This makes p-channel TFT technology preferable to n-channel for OLED on plastic. Because of the various nonuniformity issues, practical TFT circuits have more than two TFTs and a number of designs have been proposed (Hong et al 2002;He et al 2001;Akimoto et al 2002;Stryahilev et al 2002). These circuits essentially use current programming to compensate for the TFT and OLED variations.…”

A new driving method introducing a display period for AMOLEDs

“…[4][5][6] We proposed a Clamped-Inverter (CI) driving method, which generates gray scales by controlling the light-emitting period. 7 This driving method can compensate both the threshold voltage V th and mobility µ variations very well, and give good inter-pixel uniformity to the AMOLEDs.…”