Active-Matrix Micro-LED Display Driven by Metal Oxide TFTs Using Digital PWM Method
Active-Matrix Micro-LED Display Driven by Metal Oxide TFTs Using Digital PWM Method
复制标题
采用数字 PWM 方法由金属氧化物 TFT 驱动的有源矩阵 Micro-LED 显示器
DOI：
10.1109/ted.2021.3112947
复制
发表时间：
2021-11-01
影响因子：
3.1
通讯作者：
Peng, Jun-Biao
中科院分区：
文献类型：
--
作者：
Lin, Yi-Zhen;Liu, Chun;Peng, Jun-Biao
提出了一种基于数字脉宽调制（PWM）方法的微型发光二极管（LED）像素驱动电路，该电路包含了对驱动薄膜晶体管（TFT）阈值电压的补偿。设计了一个由金属氧化物薄膜晶体管（MO TFT）集成的扫描驱动器，为像素电路阵列提供扫描信号。采用背沟道刻蚀（BCE）结构的薄膜晶体管背板，同时制作<inline-formula><tex-math notation="LaTeX">了尺寸为76\，\，\times $</tex-math></inline-formula>BBB<inline-formula><tex-math notation="LaTeX">$\times\，\，78 $</tex-math></inline-formula>的微发光二极管阵列和80级扫描驱动电路。相应的微型LED显示器因此通过基于现场可编程门阵列（FPGA）的外围驱动系统来实现，该外围驱动系统用作核心控制单元以使扫描信号与数据信号同步。结果表明，在像素电路中的微发光二极管可以工作在一个恒定的电流，即使在5-<inline-formula><tex-math notation="LaTeX">$\mu \text{s}$</tex-math></inline-formula>脉宽的发射（EM）信号。在最小脉冲宽度为40<inline-formula><tex-math notation="LaTeX">μ s的</tex-math></inline-formula>电磁信号下，微发光二极管显示器可以实现256级线性灰度，闪烁频率约为60 Hz。
This article presents a new micro-light-emitting diode (LED) pixel circuit driven by the digital pulsewidth modulation (PWM) method, in which the threshold voltage compensation of the driving thin-film transistor (TFT) is included. A scan driver integrated by metal oxide (MO) TFTs is also designed to provide the scan signals for pixel circuits array. A micro-LEDs array with <inline-formula> <tex-math notation="LaTeX">$76\,\, \times $ </tex-math></inline-formula> BBB <inline-formula> <tex-math notation="LaTeX">$\times \,\,78$ </tex-math></inline-formula> and a scan driver with 80 stages are simultaneously fabricated by MO TFTs backplane with back-channel etch (BCE) structure. A respective micro-LED display is consequently realized by a peripheral driving system based on a field-programmable gate array (FPGA), which is used as a core control unit to synchronize the scan signals with the data signals. It is shown that the micro-LED in the pixel circuit can operate at a constant current even at the 5-<inline-formula> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> pulsewidth of the emission (EM) signal. The micro-LED display can achieve 256 linear grayscales with an approximately 60 Hz flash rate under the minimum pulsewidth of 40 <inline-formula> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> of EM signal.