OLED Driving Voltage Sensing Circuit for Deterioration Compensation
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Solution Overview
Problem
OLED display devices face challenges in accurately determining and compensating for the deterioration of organic light-emitting diodes (OLEDs) due to variations in driving voltage, which can lead to inconsistent luminous intensities across subpixels.
Innovation Solution
A driving voltage sensing circuit is implemented to maintain the driving voltage-for-sensing deterioration within a reference range, using a comparator and low-pass filters to accurately sense changes in capacitance and output signals to a timing controller, which adjusts the power management integrated circuit to ensure accurate compensation for OLED deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a driving voltage-for-sensing deterioration is maintained at a lower level than driving voltage during image driving period, then OLED deterioration can be accurately determined, but the sensing accuracy is compromised when driving voltage changes due to component deviations
Solution Approach 1:
The patent implements a feedback mechanism where the driving voltage-for-sensing deterioration is continuously monitored by a sensing circuit, and the timing controller adjusts the power management integrated circuit to maintain the voltage within a predetermined reference range. This closed-loop feedback ensures that voltage variations due to component deviations are compensated, maintaining reliable sensing accuracy throughout the OLED's operational life.
Solution Approach 2:
The patent dynamically adjusts the driving voltage parameter to maintain it within a predetermined reference range during the sensing period. By changing the voltage level adaptively rather than using a fixed low voltage, the system ensures optimal sensing conditions are maintained despite variations in component characteristics, thereby resolving the contradiction between sensing accuracy and reliability under voltage variation.
2Measurement precision
If driving voltage-for-sensing deterioration is kept low to ensure accurate OLED measurement, then component deviations can be minimized, but the system becomes sensitive to any voltage changes from other factors
Solution Approach 1:
The patent applies beforehand cushioning by establishing a predetermined reference range for the driving voltage-for-sensing deterioration before the sensing process begins. The timing controller proactively adjusts the power management integrated circuit to maintain the voltage within this pre-defined range, cushioning against potential voltage deviations from component variations or external factors before they can affect sensing accuracy.
Solution Approach 2:
A feedback mechanism is implemented where the actual driving voltage is continuously monitored and compared against the predetermined reference range. The timing controller receives feedback from the sensing circuit and adjusts the power management integrated circuit accordingly, creating a closed-loop system that actively compensates for voltage deviations and prevents them from introducing sensing errors.
3Reliability
If a sensing circuit is added to monitor driving voltage, then voltage stability can be maintained, but device complexity increases
Solution Approach 1:
The sensing circuit is designed with multi-functionality, serving both as a monitoring device for driving voltage and as part of the deterioration sensing system for OLEDs. The same circuit infrastructure used for voltage monitoring also supports the deterioration measurement process, eliminating the need for separate dedicated circuits and thereby reducing overall device complexity while maintaining voltage stability.
Solution Approach 2:
The patent merges the driving voltage monitoring function with the OLED deterioration sensing function into a unified sensing circuit. By combining these functions, the system avoids duplicating circuitry and reduces overall complexity. The timing controller integrates both voltage stability control and deterioration measurement operations, creating a consolidated system that achieves voltage stability without proportionally increasing complexity.
Data Source
AI summary
A driving voltage sensing circuit and a display device including the same. Deterioration of an organic light-emitting diode (OLED) disposed in each of subpixels is effectively compensated for by accurately sensing a change of charged capacitance depending on a current flowing through the organic light-emitting diode in a deterioration sensing period of the organic light-emitting diode. A driving voltage-for-sensing deterioration, applied to the display panel in the deterioration sensing period of the organic light-emitting diode, is maintained within a reference range. The deterioration of the organic light-emitting diode is accurately sensed by maintaining the driving voltage-for-sensing deterioration, applied in the deterioration sensing period, within the reference range.