OLED Driving Voltage Optimization via Current Detection

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Solution Overview

Problem

Conventional organic light emitting display devices consume unnecessary power due to a voltage margin set under assumed conditions, leading to increased power consumption despite the need for stable driving voltage for uniform light emission.

Innovation Solution

A method to set an optimal driving voltage by detecting the current variations and selecting the voltage at a turning point where the derivatives of the panel current with respect to the driving voltage are less than a threshold, reducing power consumption while maintaining stable current flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a voltage margin of about 30% is set to ensure stable driving voltage, then the uniformity of light emission is improved, but the power consumption increases unnecessarily

Engineering Contradiction:
Improvedriving voltage stabilityVSAvoidpower consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by transitioning from a static, fixed voltage margin approach to a dynamic, adaptive voltage control system. The controller continuously monitors panel current and adjusts the driving voltage in real-time based on actual operating conditions, eliminating the need for a fixed 30% voltage margin while maintaining stable light emission.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by measuring the panel current and using this information to adjust the driving voltage. The controller receives feedback about the actual current flow and modifies the voltage output accordingly, creating a closed-loop system that optimizes power consumption while ensuring uniform light emission across all emission colors.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If the driving voltage is optimized to reduce power consumption, then the energy efficiency is improved, but the stability of current flow may be compromised

Engineering Contradiction:
Improvepower consumptionVSAvoidcurrent flow stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent uses feedback control to monitor panel current and adjust driving voltage dynamically. This closed-loop approach allows the system to optimize power consumption by reducing unnecessary voltage margin while maintaining stable current flow through real-time adjustments based on actual operating conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically monitoring its own operating parameters (panel current) and making real-time modifications to the driving voltage. This self-service capability allows the display device to optimize its own power consumption without external intervention while maintaining stable operation.

Inventive Principle:
Principle #25Self-service

3Reliability

If a fixed voltage margin is used to account for temperature characteristics and emission color deviations, then the reliability of light emission uniformity is improved, but the device complexity increases

Engineering Contradiction:
Improvelight emission uniformityVSAvoidvoltage control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex pre-calculated voltage margins with a simpler feedback-based control system. Instead of implementing separate compensation mechanisms for temperature and emission color variations, the system uses real-time current monitoring to automatically adjust voltage, reducing device complexity while maintaining reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the control parameter from a fixed voltage offset to a dynamic voltage adjustment based on measured panel current. This parameter change simplifies the control mechanism by using a single measurable parameter (current) to govern voltage adjustments, eliminating the need for complex multi-parameter compensation schemes.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2282307B1Organic light emitting display device and driving voltage setting method thereof
Publication Date: 2016.05.04 SAMSUNG DISPLAY CO LTD
  • EP2282307B1 patent drawingFigure 1~2
  • EP2282307B1 patent drawingFigure 3~4

AI summary

An organic light emitting display device with reduce power consumption is disclosed. Some embodiments include a current detector which measures current over varying drive voltages. The current measurements are used to determine drive voltages for driving the display array.