LTPS AMOLED显示器像素电路阈值电压补偿效果的改善

皇甫鲁江; 朱健超; 赵旭亮; 卢江楠; 刘利宾

doi:10.37188/CJLCD.2021-0333

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LTPS AMOLED显示器像素电路阈值电压补偿效果的改善

显示技术与应用 | 更新时间：2022-03-25

- LTPS AMOLED显示器像素电路阈值电压补偿效果的改善
- Improvement of threshold voltage compensation of LTPS AMOLED pixel circuit
- 液晶与显示 2022年37卷第3期页码：358-366
- 作者机构：
  
  京东方科技集团股份有限公司技术中心，北京 100176
- 作者简介：
  
  [ "皇甫鲁江(1964-)男，山东菏泽人，博士，教授级高级工程师，2000年于西安交通大学获得博士学位，主要从事AMOLED产品技术竞争力提升相关研究。E-mail: lj.huangfu@boe.com.cn" ]
- 基金信息：
- DOI：10.37188/CJLCD.2021-0333
  中图分类号： TN27
- 收稿日期：2021-12-20，
  
  修回日期：2022-01-22，
  
  纸质出版日期：2022-03
- 稿件说明：
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皇甫鲁江, 朱健超, 赵旭亮, 等. LTPS AMOLED显示器像素电路阈值电压补偿效果的改善[J]. 液晶与显示, 2022,37(3):358-366.

Lu-jiang HUANG-FU, Jian-chao ZHU, Xu-liang ZHAO, et al. Improvement of threshold voltage compensation of LTPS AMOLED pixel circuit[J]. Chinese journal of liquid crystals and displays, 2022, 37(3): 358-366.
皇甫鲁江, 朱健超, 赵旭亮, 等. LTPS AMOLED显示器像素电路阈值电压补偿效果的改善[J]. 液晶与显示, 2022,37(3):358-366. DOI： 10.37188/CJLCD.2021-0333.

Lu-jiang HUANG-FU, Jian-chao ZHU, Xu-liang ZHAO, et al. Improvement of threshold voltage compensation of LTPS AMOLED pixel circuit[J]. Chinese journal of liquid crystals and displays, 2022, 37(3): 358-366. DOI： 10.37188/CJLCD.2021-0333.

摘要

为改善LTPS AMOLED显示器像素电路阈值电压变动性补偿效果，本文分析了相关电压型像素电路的工作过程，确认了影响阈值电压补偿效果的关键因素，包括显示信号刷新扫描行周期对阈值电压获取充电时间的制约、驱动信号形成过程中相关TFT电容增量造成的阈值电压精度损失等。针对这些关键因素，本文提出了像素电路改进对策。通过分离阈值电压获取和数据电压信号刷新过程实现阈值电压获取充电时间的延长，通过反向增量电容补偿相关电容增量误差。在像素OLED驱动电流受阈值电压变动影响突出的低灰阶状态下，模拟结果表明阈值电压获取和数据电压信号刷新过程分离像素电路的OLED驱动电流变动性是参考电路的1/7；反向增量电容补偿像素电路OLED驱动电流变动性大约为无补偿参考电路的1/2。补偿效果样品视觉评价结果与模拟结果趋势相符。

Abstract

The key factors affecting threshold voltage variation compensation are identified through analyzing the operation processes of a relevant voltage program LTPS AMOLED pixel circuit. The factors include charging time restriction on threshold voltage detecting process due to data voltage signal refreshing period

and accuracy loss of threshold voltage in voltage program caused by capacity increment of related TFTs. Circuit countermeasure to these adverse factors are put forward to extend the charging time through separating the threshold voltage detection from data voltage signal refreshing process

and to compensate the error due to capacity increment through a TFT with reversed capacity increment. In pixel circuit state simulation under a low grey level display state

the variation of OLED driving current of pixel circuit of separated threshold voltage detection and data voltage signal refreshing is less than a seventh current variation of the reference circuit

and the variation of OLED driving current with capacity increment compensation is about half the current variation of the pixel circuit without capacity increment compensation. The improving effects in samples demonstration are consistent with the trend of simulation results.

关键词

Keywords

references

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