He Wenyao, Yi Zichuan, Shen Shitao, Huang Zhenyu, Liu Linwei, Zhang Taiyuan, Li Wei, Wang Li, Shui Lingling, Zhang Chongfu, Zhou Guofu
College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China.
Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
Micromachines (Basel). 2020 May 14;11(5):498. doi: 10.3390/mi11050498.
Electrophoretic displays (EPDs) have excellent paper-like display features, but their response speed is as long as hundreds of milliseconds. This is particularly important when optimizing the driving waveform for improving the response speed. Hence, a driving waveform design based on the optimization of particle activation was proposed by analyzing the electrophoresis performance of particles in EPD pixels. The particle activation in the driving waveform was divided into two phases: the improving particle activity phase and the uniform reference grayscale phase. First, according to the motion characteristics of particles in improving the particle activity phase, the real-time EPD brightness value can be obtained by an optical testing device. Secondly, the derivative of the EPD brightness curve was used to obtain the inflection point, and the inflection point was used as the duration of improving particle activity phase. Thirdly, the brightness curve of the uniform reference grayscale phase was studied to set the driving duration for obtaining a white reference grayscale. Finally, a set of four-level grayscale driving waveform was designed and validated in a commercial E-ink EPD. The experimental results showed that the proposed driving waveform can cause a reduction by 180 ms in improving particle activity phase and 120 ms in uniform reference grayscale phase effectively, and a unified reference grayscale can be achieved in uniform reference grayscale phase at the same time.
电泳显示器（EPD）具有出色的类纸显示特性，但其响应速度长达数百毫秒。在优化驱动波形以提高响应速度时，这一点尤为重要。因此，通过分析EPD像素中粒子的电泳性能，提出了一种基于粒子激活优化的驱动波形设计。驱动波形中的粒子激活分为两个阶段：提高粒子活性阶段和均匀参考灰度阶段。首先，根据粒子在提高粒子活性阶段的运动特性，利用光学测试装置获取EPD实时亮度值。其次，利用EPD亮度曲线的导数得到拐点，并将该拐点作为提高粒子活性阶段的持续时间。第三，研究均匀参考灰度阶段的亮度曲线，设定获得白色参考灰度的驱动持续时间。最后，设计了一组四级灰度驱动波形，并在商用电子墨水EPD中进行了验证。实验结果表明，所提出的驱动波形能够有效使提高粒子活性阶段减少180 ms，均匀参考灰度阶段减少120 ms，同时在均匀参考灰度阶段能够实现统一的参考灰度。
