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Ultra-low Power AMOLED Displays for Smart Wearable Applications: Theory and Practice

Bojia Lyu

TL;DR

This work investigates ultra-low-power AMOLED displays for smart wearables by treating the display as a coupled system of five components and presenting targeted, interdependent optimization strategies. It details power-saving techniques across the power chip, driver chip, array substrate, light-emitting structure, and light-transmitting structure, and demonstrates how hybrid power delivery, voltage/frequency tuning, and dynamic control can yield substantial savings in normal, idle, and standby modes. Key contributions include quantifiable reductions (e.g., up to ~30% in idle mode via optimized driver boost/config, ~20% via voltage-conversion bypass, and ~10% through voltage-setting adjustments) and practical approaches such as automatic optimization with feedback, LTPO/LTPS integration, and advanced light-extraction methods (MLP/COE). Together, these strategies enable longer standby times and lower power consumption in wearable AMOLEDs, with implications for device size, battery life, and performance in real-world usage.

Abstract

With the continuous advancement and maturity of AMOLED (Active-Matrix Organic Light Emitting Diode) technology, smart wearable products such as watches and bracelets are increasingly incorporating related technologies as display screen implementation solutions. Using standby time is the most critical product performance measurement indicator at the moment, according to the power supply system design of smart wearable products and customer usage habits. AMOLED displays, as one of the major power-consuming components in smart wearable products, are also subject to extremely stringent power consumption requirements. This paper divides an AMOLED display into five parts: the power chip, the driver chip, the array substrate, the light-emitting structure, and the light-transmitting structure. In this paper, we propose targeted power-saving solutions for each component based on their respective operating principles, subject areas, and the most recent advances in related fields, and we provide the best overall solution by combining the interactions between each component and even the entire system. The relevant solutions have been validated in practice, and there is clear verification data to demonstrate their feasibility.

Ultra-low Power AMOLED Displays for Smart Wearable Applications: Theory and Practice

TL;DR

This work investigates ultra-low-power AMOLED displays for smart wearables by treating the display as a coupled system of five components and presenting targeted, interdependent optimization strategies. It details power-saving techniques across the power chip, driver chip, array substrate, light-emitting structure, and light-transmitting structure, and demonstrates how hybrid power delivery, voltage/frequency tuning, and dynamic control can yield substantial savings in normal, idle, and standby modes. Key contributions include quantifiable reductions (e.g., up to ~30% in idle mode via optimized driver boost/config, ~20% via voltage-conversion bypass, and ~10% through voltage-setting adjustments) and practical approaches such as automatic optimization with feedback, LTPO/LTPS integration, and advanced light-extraction methods (MLP/COE). Together, these strategies enable longer standby times and lower power consumption in wearable AMOLEDs, with implications for device size, battery life, and performance in real-world usage.

Abstract

With the continuous advancement and maturity of AMOLED (Active-Matrix Organic Light Emitting Diode) technology, smart wearable products such as watches and bracelets are increasingly incorporating related technologies as display screen implementation solutions. Using standby time is the most critical product performance measurement indicator at the moment, according to the power supply system design of smart wearable products and customer usage habits. AMOLED displays, as one of the major power-consuming components in smart wearable products, are also subject to extremely stringent power consumption requirements. This paper divides an AMOLED display into five parts: the power chip, the driver chip, the array substrate, the light-emitting structure, and the light-transmitting structure. In this paper, we propose targeted power-saving solutions for each component based on their respective operating principles, subject areas, and the most recent advances in related fields, and we provide the best overall solution by combining the interactions between each component and even the entire system. The relevant solutions have been validated in practice, and there is clear verification data to demonstrate their feasibility.

Paper Structure

This paper contains 37 sections, 3 equations, 35 figures, 5 tables.

Table of Contents

  1. Introduction
  2. Optical Specifications
  3. Power Consumption Specifications
  4. Evaluation Criteria
  5. Normal Mode
  6. Boost Mode
  7. Idle Mode
  8. Standby Mode
  9. Power Chip
  10. Inductor Selection
  11. Quiescent Current
  12. Conversion Mode
  13. Driver Chip
  14. Analog Circuit Section
  15. Boost Mode Configuration
  16. ...and 22 more sections

Figures (35)

  • Figure 1: AMOLED display system components for smart wearable application
  • Figure 2: AMOLED display system components for smart wearable application
  • Figure 3: Efficiency curves of power chip S and chip A at the same voltage (PVDD/PVEE=3.3V/-3.3V) setting.
  • Figure 4: Efficiency curves of power chip S at different voltage settings.
  • Figure 5: Typical application circuit of power chip R, include capacitors, resistors and inductors.
  • ...and 30 more figures