P-20: An AMOLED Pixel for the VT Compensation of TFT and a p-Type LTPS Shift Register by Employing 1 Phase Clock Signal

Abstract

A voltage modulated AMOLED pixel design using low temperature polycrystalline silicon thin film transistor (LTPS-TFT) is proposed. The proposed pixel, which consists of 5 p-type LTPS TFTs and 1-capacitor, successfully suppressed the threshold voltage variation problem in LTPS TFTs and OLEDs. A new ptype LTPS shift register employing only 1 clock signal is also proposed for the integration driving circuits. In order to eliminate the clock skew problem, only 1 phase clock signal is used in the proposed shift register. The proposed circuits were verified by simulation and experimental results.

56.4: Dual‐Gate IGZO TFT for Threshold‐ Voltage Compensation in AMOLED Pixel Circuit

“…In this paper, we propose a new concept of using the top-gate to compensate the Vth difference in the pixel circuit of active matrix organic light emitting diode (AMOLED), since the Vth shift issue in the AMOLED circuit is most critical [6][7]. Some pixel circuits take many TFTs to implement the function, which can lower the aperture of the display pixel [8][9][10][11][12][13][14]. To make the aperture large while keeping the Vth compensation function, several pixel circuits composed of fewer transistors were proposed [15][16].…”

A Charge-Sensing-Capable Source Driver for TFT Array Testing in System-on-Panel Displays

“…Most TFT arrays are fabricated using the LTPS or a-Si technology. Compared to the mainstream CMOS technology, LTPS and a-Si TFT devices suffer low mobility and V t variations [12], [13], [14], [15]. In particular, LTPS process is prone to spatial V t variations while a-Si process is prone to temporal V t variations.…”

15‐1: PWM Pixel Circuit with LTPS TFTs for Micro‐LED Displays

“…AMLCDs and AMOLEDs products are mostly using the PAM pixel circuit. The pixel driving circuit with PWM has a different pulse amplitude modulation (PAM) concept from the conventional pixel driving circuit in AMLCDs and AMOLEDs [7][8]. In this paper, we propose a new pixel driving circuit using LTPS TFTs to implement the PWM operation.…”