OLED Subpixel Threshold Sensing for Deterioration Compensation
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Solution Overview
Problem
Existing display devices face challenges in accurately determining the deterioration of organic light emitting diodes (OLEDs) in subpixels, leading to reduced display quality and lifespan.
Innovation Solution
A display device and driving method that senses the threshold voltage of OLEDs in subpixels by using a reference line and sensing circuit, with a power supply and activation switch to determine deterioration and generate compensation values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensing circuit is added to detect OLED threshold voltage, then measurement precision of OLED deterioration is improved, but device complexity increases
Solution Approach 1:
The sensing circuit is merged with the existing power supply circuitry, sharing common components such as the power control transistor and reference line. This integration allows the sensing function to be achieved without adding completely separate circuit blocks, thereby improving measurement precision while limiting the increase in device complexity.
Solution Approach 2:
The power supply circuit is designed to serve dual purposes: normal power delivery to the OLED and simultaneous sensing of the threshold voltage. The same reference line and power control transistor are used both for powering the display and for sensing operations, making the circuit multi-functional and reducing overall complexity.
2Reliability
If threshold voltage sensing is performed continuously, then reliability of OLED monitoring is improved, but use of energy increases
Solution Approach 1:
The threshold voltage sensing is performed periodically rather than continuously. The sensing operation is activated at specific intervals during the display operation cycle, allowing the system to monitor OLED deterioration reliability while minimizing energy consumption by keeping the sensing circuit inactive between measurement periods.
Solution Approach 2:
The sensing operation is integrated into the existing display timing cycle, performing threshold voltage measurement during periods when the display is already operational or in transition states. This ensures continuous monitoring capability without requiring separate dedicated sensing time, maintaining reliability while optimizing energy usage.
3Measurement precision
If power control transistor is added to block low-voltage power, then measurement precision of voltage sensing is improved, but device complexity increases
Solution Approach 1:
The power control transistor is merged with the existing power supply circuit architecture, serving as a common component for both power delivery control and voltage sensing operations. This integration allows precise voltage sensing through the same transistor that controls power delivery, improving measurement precision without proportionally increasing device complexity.
Data Source
AI summary
Disclosed is a display device including a subpixel including a light emitting element, a reference line connected to the subpixel, a power supply configured to provide a path for transmitting a voltage present at a cathode of the light emitting element to the reference line, and a sensing circuit configured to sense a voltage present on the reference line.