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Red Ghost Image Elimination Method Based on Driving Waveform Design in Three-Color Electrophoretic Displays. MICROMACHINES 2022; 13:mi13020275. [PMID: 35208398 PMCID: PMC8875704 DOI: 10.3390/mi13020275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 12/10/2022]
Abstract
Three-color electrophoretic displays (EPDs) are a new type of optoelectronic display device. However, they have the defect of red ghost images during gray scale transformation, which affects the accuracy of the gray scale display. In this paper, we proposed a new driving method for eliminating the red ghost images. A driving waveform was composed of an erasing stage, an activation stage, and a driving stage. First, the erasing stage was subdivided into a red erasing stage and an original erasing stage, the red erasing stage was used to eliminate residual red particles in the top of the microcapsules. Then, a high-frequency square wave was used as the activation stage for increasing the activity of the black and white particles. Meanwhile, the intensity of flickers could be decreased by the high-frequency square wave. Finally, the performance of the driving waveform was tested by a colorimeter. The experimental results showed that the driving waveform could effectively eliminate red ghost images by 80.43% and reduce the flicker intensity by 79.63%, compared with an existing driving waveform.
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Zhang H, Yi Z, Liu L, Chi F, Hu Y, Huang S, Miao Y, Wang L. A Fast-Response Driving Waveform Design Based on High-Frequency Voltage for Three-Color Electrophoretic Displays. MICROMACHINES 2021; 13:59. [PMID: 35056224 PMCID: PMC8777687 DOI: 10.3390/mi13010059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 12/26/2021] [Accepted: 12/26/2021] [Indexed: 11/16/2022]
Abstract
Three-color electrophoretic displays (EPDs) have the characteristics of colorful display, reflection display, low power consumption, and flexible display. However, due to the addition of red particles, response time of three-color EPDs is increased. In this paper, we proposed a new driving waveform based on high-frequency voltage optimization and electrophoresis theory, which was used to shorten the response time. The proposed driving waveform was composed of an activation stage, a new red driving stage, and a black or white driving stage. The response time of particles was effectively reduced by removing an erasing stage. In the design process, the velocity of particles in non-polar solvents was analyzed by Newton's second law and Stokes law. Next, an optimal duration and an optimal frequency of the activation stage were obtained to reduce ghost images and improve particle activity. Then, an optimal voltage which can effectively drive red particles was tested to reduce the response time of red particles. Experimental results showed that compared with a traditional driving waveform, the proposed driving waveform had a better performance. Response times of black particles, white particles and red particles were shortened by 40%, 47.8% and 44.9%, respectively.
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Affiliation(s)
- Hu Zhang
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zichuan Yi
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
| | - Liming Liu
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
| | - Feng Chi
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
| | - Yunfeng Hu
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
| | - Sida Huang
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
| | - Yu Miao
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (H.Z.); (L.L.); (F.C.); (Y.H.); (S.H.); (Y.M.)
| | - Li Wang
- School of Information Engineering, Zhongshan Polytechnic, Zhongshan 528400, China;
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Zeng W, Yi Z, Zhou X, Zhao Y, Feng H, Yang J, Liu L, Chi F, Zhang C, Zhou G. Design of Driving Waveform for Shortening Red Particles Response Time in Three-Color Electrophoretic Displays. MICROMACHINES 2021; 12:578. [PMID: 34069735 PMCID: PMC8161037 DOI: 10.3390/mi12050578] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 01/18/2023]
Abstract
Three-color electrophoretic displays (EPDs) have the advantages of multi-color display and low power consumption. However, their red particles have the disadvantage of long response time. In this paper, a driving waveform, which is based on electrophoresis theory and reference gray scale optimization, was proposed to shorten the response time of red particles in three-color EPDs. The driving waveform was composed of erasing stage, reference gray scale forming stage, red driving stage, and white or black driving stage. Firstly, the characteristics of particle motion were analyzed by electrophoresis theory and Stokes law. Secondly, the reference gray scale of the driving waveform was optimized to shorten the distance between red particles and a common electrode plate. Finally, an experimental platform was developed to test the performance of the driving waveform. Experimental results showed that the proposed driving waveform can shorten the response time of red particles by 65.57% and reduce the number of flickers by 66.67% compared with the traditional driving waveform.
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Affiliation(s)
- Wenjun Zeng
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China;
| | - Zichuan Yi
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Xichen Zhou
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Yiming Zhao
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Haoqiang Feng
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China;
| | - Jianjun Yang
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Liming Liu
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Feng Chi
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Chongfu Zhang
- College of Electron and Information, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, China; (W.Z.); (X.Z.); (Y.Z.); (H.F.); (J.Y.); (L.L.); (F.C.); (C.Z.)
| | - Guofu Zhou
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China;
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Yi Z, Zeng W, Ma S, Feng H, Zeng W, Shen S, Shui L, Zhou G, Zhang C. Design of Driving Waveform Based on a Damping Oscillation for Optimizing Red Saturation in Three-Color Electrophoretic Displays. MICROMACHINES 2021; 12:162. [PMID: 33562290 PMCID: PMC7915761 DOI: 10.3390/mi12020162] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 01/23/2023]
Abstract
At present, three-color electrophoretic displays (EPDs) have problems of dim brightness and insufficient color saturation. In this paper, a driving waveform based on a damping oscillation was proposed to optimize the red saturation in three-color EPDs. The optimized driving waveform was composed of an erasing stage, a particles activation stage, a red electrophoretic particles purification stage, and a red display stage. The driving duration was set to 360 ms, 880 ms, 400 ms, and 2400 ms, respectively. The erasing stage was used to erase the current pixel state and refresh to a black state. The particles' activation stage was set as two cycles, and then refreshed to the black state. The red electrophoretic particles' purification stage was a damping oscillation driving waveform. The red and black electrophoretic particles were separated by changing the magnitude and polarity of applied electric filed, so that the red electrophoretic particles were purified. The red display stage was a low positive voltage, and red electrophoretic particles were driven to the common electrode to display a red state. The experimental results showed that the maximum red saturation could reach 0.583, which was increased by 27.57% compared with the traditional driving waveform.
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Affiliation(s)
- Zichuan Yi
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
| | - Weibo Zeng
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
| | - Simin Ma
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
| | - Haoqiang Feng
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (S.S.); (G.Z.)
| | - Wenjun Zeng
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (S.S.); (G.Z.)
| | - Shitao Shen
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (S.S.); (G.Z.)
| | - Lingling Shui
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (S.S.); (G.Z.)
| | - Guofu Zhou
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (S.S.); (G.Z.)
| | - Chongfu Zhang
- College of Electron and Information, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, China; (Z.Y.); (W.Z.); (S.M.); (W.Z.); (L.S.); (C.Z.)
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