Enhancement of picture quality on ultra-low brightness by optimizing the electrical potential required for OLED charging in the AMOLED displays

Se Hwan Na, Won Kyung Min, Do Hyung Kim, Han Wook Hwang, Yong Min Ha, Hyun Jae Kim

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)

Abstract

The principal causes of the poor picture quality on active matrix organic light-emitting diode (AMOLED) displays, operating under extremely low brightness and gray-scale conditions, were analyzed and verified by measuring and modelling of the electrical simulations. Through the analysis, it was found that the deteriorated picture quality was induced by a delayed saturation voltage, which means the electric potential difference between the initial voltage applied to the anode of the OLED (Vinit) and the OLED saturated voltage (Vsat) for emission. This is because the deviations of pico-ampere-level currents and delayed OLED charging prior to light emission increased the saturation voltage when there were low driving currents. Thus, we optimized the voltage by increasing Vinit from −4.5 to −2.7 V, effectively eliminating image deterioration by reducing the OLED charging delay. Thus, the proposed approach opens up advancements of obtaining superior picture quality with ultra-low luminance, even in the dark illuminance environments. We discuss how OLED picture quality may be enhanced under low brightness, including the driving methods, design considerations, and processes involved.

Original languageEnglish
Pages (from-to)275-284
Number of pages10
JournalJournal of Information Display
Volume22
Issue number4
DOIs
Publication statusPublished - 2021

Bibliographical note

Publisher Copyright:
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the Korean Information Display Society.

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Electrical and Electronic Engineering

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