Electroluminescent Subpixel Leakage Detection via Readout-Line Sensing
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Solution Overview
Problem
Existing electroluminescent display apparatuses lack a method to detect leakage in driving elements, making it difficult to differentiate between leakage and other defects such as short circuits or open defects, which affects display quality.
Innovation Solution
Incorporation of a first subpixel circuit with a driving element, light emitting device, switch elements, monitoring elements, and a sensing circuit to detect leakage current by sensing the voltage of a readout line during specific detection periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If no leakage detection method is implemented, then the device complexity remains low, but the measurement precision of driving element defects is insufficient
Solution Approach 1:
The detection process is segmented into distinct time periods: a first detection period where the driving element is turned off and leakage current is measured, and a second detection period where the light emitting device is tested. This temporal segmentation allows leakage detection without requiring additional parallel circuitry, thus improving measurement precision while controlling device complexity.
Solution Approach 2:
The leakage current is detected before the light emitting device is activated. By performing the leakage measurement in advance during the first detection period, the system can identify defective driving elements before they cause display artifacts, improving defect detection precision without adding complex real-time monitoring circuits.
2Reliability
If leakage detection is implemented during normal operation, then the reliability improves, but the productivity decreases due to additional detection time
Solution Approach 1:
Leakage detection is performed periodically during dedicated detection periods rather than continuously. The gate driver alternates between normal display operation and detection modes, allowing leakage measurements to be taken at regular intervals without requiring continuous monitoring, thus maintaining reliability while preserving productivity.
Solution Approach 2:
Leakage detection is performed in advance before display content is rendered. By completing leakage measurements during the first detection period before the second detection period (where light emitting devices are tested), the system ensures reliable defect identification without delaying the actual display output, maintaining both reliability and productivity.
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
Accurately detects leakage in driving elements of subpixels, enabling precise identification and correction of defects, thereby maintaining display quality.
Implementation Method 1
a sensing circuit configured to sense a voltage of the readout line in a first detection period where the first and second switch elements and the first monitoring element are turned on
Data Source
AI summary
An electroluminescent display apparatus includes: a first subpixel circuit including a first driving element including a gate electrode connected to a first node and a source electrode connected to a second node, a first light emitting device connected to the second node, a first switch element connecting the first node to a first data line charged with a detection data voltage according to a scan signal, a second switch element connected to the second node at one electrode thereof and turned on based on the scan signal, and a first monitoring element connecting a readout line to the other electrode of the second switch element according to a first monitoring signal; and a gate driver configured to supply the scan signal to gate electrodes of the first and second switch elements and supply the first monitoring signal to a gate electrode of the first monitoring element.