11‐5: Late‐News Paper: High PPI Micro LED Display for Small and Medium Size

A compact gate driver on array (GOA) was proposed for Micro‐Light Emitting diodes (Micro‐LED) display based on progressive‐mode pulse‐width modulation (PWM) using low‐temperature‐polysilicon (LTPS) thin‐film transistors (TFTs). Thanks to outputting line‐by‐line scanning (Scan) and emission control signals (EM) to address switching‐and emission‐transistors in Micro‐LED pixel circuit, the proposed GOA circuit enables an increased emission time by 60% with the frame rate of 120 Hz, compared with the conventional GOA circuit of simultaneous operating mode. Furthermore, the pulse‐width of EM signals are programmable simply by adjusting the number of input pulses.

“…During the bootstrapping period, the level of Qa-node is decreased to -4.5V. And the scanning signal P [1] and emission control signals EM [1] output correspondingly. Fig.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

38.3: Compact Gate Driver on Array for Progressive‐mode PWM Micro‐LED Display using LTPS TFTs

Zhu

Song

Zhao

et al. 2023

“…Micro light-emitting-diode (Micro-LED) is promising technology of next-generation displays, due to advantages of ultra-high brightness, fast response, high stability and low power consumption [1,2]. Being different with conventional displays, Micro-LED performance is ultra-sensitive to driving-current variations since luminous efficiency (EQE) and emission wavelength vary with the driving-currents [3,4].…”

Section: Introductionmentioning

confidence: 99%

P‐9: LTPO TFTs Based PWM Pixel Circuit for AM‐Micro‐LED Display with Falling‐time <10μs

Liu,

Que,

Liao

et al. 2023

A pulse‐width‐modulation (PWM) pixel circuit for Micro‐LED display based on low‐temperature poly‐silicon and oxide (LTPO) thin‐film transistor (TFT) is proposed. The PWM falling‐time is reduced to 10 μs, which is only 1/10 of conventional PWM pixel schematics, thanks to the high gain dynamic CMOS inverter for converting data voltage to PWM waveforms and an independent diode‐connected compensation structure for generating constant driving current. The maximum error of PWM conversion and driving current of Micro‐LED is less than 1%, despite VTH shift of oxide TFT ±2 V or VTH variation of LTPS TFT ±1 V. Furthermore, high display resolution above 270 PPI is obtained as the pixel layout reduced to 94 μm×94 μm due to the simplified pixel structure.

“…The micro-light-emitting diode (micro-LED) displays are considered as the next generation displays due to several superior characteristics such as high brightness, low power consumption, and long lifetime. Thus, the micro-LED displays could be widely used in many applications such as large-size TVs, AR/VR displays, and car displays [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

P‐63: Simple Pixel Circuit with External Compensation for High PPI Active‐Matrix MicroLED Displays Using PWM Method

Hung,

Chiu,

Chen

et al. 2023

This work presents a novel pixel circuit that consists of five transistors and two capacitors for active‐matrix micro‐LED (AMμLED) displays. The proposed pixel circuit uses external compensation to compensate for variations in the low‐temperature polycrystalline‐silicon thin‐film transistor (LTPS TFT) threshold voltage and adopts pulse width modulation (PWM) to modulate the grayscale. According to the simulation results and a layout example, the proposed pixel circuit is expected to be applied in high pixels per inch (PPI) car displays in the future.