Reducing Leakage Current Using LTPS-TFT Pixel Circuit in AMOLED Smartwatch Displays

Chih Lung Lin, Po Cheng Lai, Jui Hung Chang, Yi Chien Chen, Po Chun Lai, Li Wei Shih

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


This article proposes a new pixel circuit that is operated at a low frame rate using low-temperature polycrystalline silicon thin-film transistors (TFTs) for use in active-matrix organic light-emitting diode (AMOLED) smartwatch displays. The proposed circuit uses a new leakage-prevention method (LPM) to balance the off currents at the gate node of the driving TFTs, eliminating the drop of the driving voltage. Uniform OLED currents are thus generated throughout the extended emission period. Also, the OLEDs are all turned off except in the emission stage to suppress image flicker. To confirm the feasibility of the proposed pixel circuit, a 1.41-inch panel, based on the proposed circuit, is fabricated. Experimental results demonstrate that diminishing the off currents maintains the driving capability of the pixel circuit to stabilize the luminance of the fabricated panel. The exhibitions of red, green, blue, and white images at frame rates from 60 Hz to 15 Hz are uniform, verifying that the proposed pixel circuit with LPM has high potential for use in AMOLED smartwatch displays with a low frame rate.

Original languageEnglish
Pages (from-to)8588-8597
Number of pages10
JournalIEEE Transactions on Industrial Electronics
Issue number8
Publication statusPublished - 2023 Aug 1

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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