OLED Driving Power Optimization via Panel-Specific Voltage Adjustment
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Solution Overview
Problem
Existing organic light emitting display technologies apply a uniform high potential driving power (VDDEL) to all display panels, leading to unnecessary voltage margins, especially in best-performing panels, resulting in increased power consumption, which is particularly problematic for mobile and wearable devices with limited battery capacity.
Innovation Solution
A method to optimize the high potential driving power (VDDEL) for each display panel by sensing changes in driving characteristics and adjusting the voltage level to ensure the power operates within an active region, minimizing voltage margins and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform high potential driving power (VDDEL) is applied to all display panels with a voltage margin to ensure operation in the saturation region, then the stability and reliability of the driving TFT operation is improved, but the power consumption increases unnecessarily for best-performing panels
Solution Approach 1:
The patent applies different VDDEL values to different display panels based on their individual characteristics. Specifically, it classifies panels into first type (best-performing) and second type (worst-performing) and applies optimized VDDEL to the first type while maintaining higher VDDEL for the second type, ensuring each panel receives appropriate power levels for its performance level
Solution Approach 2:
The patent changes the VDDEL parameter based on panel characteristics and operating conditions. It dynamically adjusts VDDEL by applying a first optimized value to first type panels and a second value to second type panels, and further adjusts within panels based on sensed current levels, transforming the fixed uniform parameter into a variable adaptive parameter
2Reliability
If a high VDDEL with sufficient voltage margin is applied to account for process deviations and characteristic changes, then the driving TFT can always operate in the saturation region, but the voltage margin becomes excessively large for best-performing panels leading to wasted energy
Solution Approach 1:
The patent implements a dynamic adjustment mechanism where VDDEL is not fixed but is adjusted based on sensed current characteristics. It senses the current level during a sensing period and dynamically selects between a first VDDEL value (for current above threshold) and a second VDDEL value (for current below threshold), allowing the system to adapt to actual panel performance rather than relying on static margins
Solution Approach 2:
The patent employs feedback by sensing the actual current drawn by each display panel and using this information to adjust the VDDEL. The controller senses current levels and uses this feedback to determine whether to apply the first or second VDDEL value, creating a closed-loop control system that optimizes power delivery based on actual panel needs
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for reduced power consumption and heat generation, optimizing power usage in mobile and wearable devices by tailoring the VDDEL to each panel's characteristics, ensuring efficient operation and extending device lifespan.
Implementation Method 1
When a driving voltage is applied to the anode electrode and the cathode electrode, holes passing through the hole transport layer HTL and electrons passing through the electron transport layer ETL move to the emission layer EML and form excitons. As a result, the emission layer EML generates visible light.
Data Source
AI summary
An organic light emitting display includes a display panel including a plurality of pixels, each pixel among the plurality of pixels including an organic light emitting diode (OLED) connected between a first potential driving power having an initial value and a second potential driving power, and a driving thin film transistor (TFT) connected between the first potential driving power and the second potential driving power; a driver integrated circuit (IC) configured to drive the display panel; a power IC configured to apply the first potential driving power to the display panel; and a sensing unit configured to sense changes in driving characteristics of the display panel each time the first potential driving power varies from an initial value of the first potential driving power in a state where the initial value of the first potential driving power and a test pattern are applied to the display panel.