Metal oxide TFTs gate driver and analog PWM pixel circuit employing progressive slope-compensated ramp signal for micro-LED displays

IF 3.4 2区工程技术 Q1 COMPUTER SCIENCE, HARDWARE & ARCHITECTURE

Displays Pub Date : 2025-09-23 DOI:10.1016/j.displa.2025.103230

Lirong Zhang , Lei Zhou , Zhong Zheng , Zhaohua Zhou , Miao Xu , Lei Wang , Weijing Wu , Junbiao Peng

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引用次数: 0

Abstract

A new metal oxide thin film transistors (MO TFT) gate driver has been presented for micro light-emitting diode (Micro-LED) displays with line-by-line driving method, where progressive and adjustable slope-compensated ramp signals are employed into each row of pixel array. A compensated analog pulse width modulation (PWM) pixel circuit is presented to construct the Micro-LED driving framework. This proposed gate driver with one input module and three output modules provides all the control signals for pixel array without any external integrated circuits (ICs), which simplifying the driving system. The experimented results show that the gate driver outputs integrated signals, including SCAN, EM and PWM. And the pixel circuit with single Micro-LED chip could achieve different grayscale levels from (100 to 3000 cd/m²), successfully. The slope and current of Micro-LED (I_LED) can be adjusted by applying an external bias, where the slope ranges from −0.35 to −0.57 within a bias range of −6 to −7 V, while I_LED varies from 17.3 to 61.7 μA under a bias range of 3 to 9 V. Then, the error rate of slope and brightness can achieve within 2 % and 5 % with V_th shift of about ±0.7 V after undergoing 1.5 h positive and negative bias stress test of TFT, respectively. Moreover, the proposed gate driver and pixel circuit have been verified to operate normally at high speeds with SCAN output width of 8.68 us, 6.51 us and 4.32 us, which is suitable for high-resolution Micro-LED displays.

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用于微型led显示器的金属氧化物TFTs栅极驱动器和采用递进斜率补偿斜坡信号的模拟PWM像素电路

提出了一种用于微发光二极管（micro - led）显示器的新型金属氧化物薄膜晶体管（MO TFT）栅极驱动器，该驱动器采用逐行驱动方法，在每一行像素阵列中采用递进和可调的斜率补偿斜坡信号。提出了一种补偿模拟脉宽调制（PWM）像素电路来构建微型led驱动框架。该栅极驱动器采用1个输入模块和3个输出模块，无需任何外部集成电路即可提供像素阵列的所有控制信号，从而简化了驱动系统。实验结果表明，该栅极驱动器输出包括SCAN、EM和PWM在内的集成信号。采用单个Micro-LED芯片的像素电路可以成功实现（100 ~ 3000 cd/m2）的不同灰度级。Micro-LED （ILED）的斜率和电流可以通过施加外部偏置来调节，其中在- 6至- 7 V的偏置范围内，斜率范围为- 0.35至- 0.57，而在3至9 V的偏置范围内，ILED的变化范围为17.3至61.7 μA。经过1.5 h的TFT正、负偏置应力测试，斜率和亮度的错误率分别在2%和5%以内，Vth位移约为±0.7 V。此外，所提出的栅极驱动器和像素电路已被验证在高速下正常工作，SCAN输出宽度为8.68 us， 6.51 us和4.32 us，适用于高分辨率Micro-LED显示器。

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来源期刊

Displays 工程技术-工程：电子与电气

CiteScore

4.60

自引率

25.60%

发文量

138

审稿时长

92 days

期刊介绍： Displays is the international journal covering the research and development of display technology, its effective presentation and perception of information, and applications and systems including display-human interface. Technical papers on practical developments in Displays technology provide an effective channel to promote greater understanding and cross-fertilization across the diverse disciplines of the Displays community. Original research papers solving ergonomics issues at the display-human interface advance effective presentation of information. Tutorial papers covering fundamentals intended for display technologies and human factor engineers new to the field will also occasionally featured.