Organic EL Display Current Compensation via Averaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic EL display devices face challenges in accurately compensating for variations in threshold voltages of drive transistors and degradation of organic EL elements due to noise and error-prone current data, leading to degraded display quality, and current compensation methods require complex analog circuits and high manufacturing costs.
Innovation Solution
An active matrix display device with a current measuring unit and average value calculation unit that measures current multiple times and calculates an average value, reducing noise influence through low-pass filtering, and transmits data at a lower rate to an external device for compensation computation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current is measured using conventional current monitoring function, then compensation for degradation can be performed, but noise and variations in current detecting circuitry cause large errors in current data
Solution Approach 1:
The patent combines multiple current measurement values obtained at different timings into a single average value. By merging multiple measurements (first measurement value at time t1, second measurement value at time t2) and calculating their average, the system reduces the impact of noise and circuit variations on the final compensation data, thereby improving both measurement precision and compensation reliability.
2Measurement precision
If complex analog circuits are used for current compensation, then compensation precision can be improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent replaces complex analog current compensation circuits with a digital measurement and calculation system. Instead of using sophisticated analog circuitry to achieve precise current compensation, the system uses multiple digital measurements taken at different timings, processes them through averaging calculation, and obtains accurate compensation data. This substitution of digital processing for analog circuit complexity reduces device complexity while maintaining or improving precision.
3Measurement precision
If multiple current measurements are taken and averaged, then noise influence is reduced, but measurement time increases
Solution Approach 1:
The patent employs periodic measurements at specifically timed intervals (first measurement at time t1, second measurement at time t2) rather than continuous measurement. This periodic sampling approach allows the system to capture sufficient data for noise reduction through averaging while minimizing the total measurement time. The periodic nature of the measurements ensures that noise is reduced without requiring excessive measurement duration.
Data Source
AI summary
The organic EL display device includes: a current monitoring section that measures a current flowing in a circuit element and outputs a digital measured value in accordance with the measured current; and an averaging section (36) that calculates an average value of a plurality of input values. The current monitoring section measures the current flowing in a circuit element in each pixel circuit a plurality of times in a fixed amount of time. For each pixel circuit, the averaging section (36) receives a plurality of measured values outputted from the current monitoring section in a fixed amount of time as a plurality of input values and outputs an average value of the plurality of digital measured values as a value for use in compensation computation to compensate for degradation of the circuit element.