OLED Short Circuit Detection via Reference Voltage Measurement
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Solution Overview
Problem
Organic light-emitting display devices face issues with electrical short-circuits between the first and second electrodes of OLEDs, leading to improper diode function and reduced image quality due to exposure to impurities or moisture during fabrication or shipment.
Innovation Solution
An organic light-emitting display device with a driving circuit and controller that includes a sensor to detect short circuits by initializing and measuring the voltage of a reference voltage line, allowing accurate detection and potential repair of defective subpixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If OLEDs are used in organic light-emitting display devices, then high response rates and high luminance are achieved, but electrical short-circuits may occur between electrodes due to impurities or moisture exposure
Solution Approach 1:
The patent performs preliminary detection of short circuits in OLEDs during the fabrication process or before shipment by measuring voltage changes across the OLED structure. This early detection allows defective OLEDs to be identified and separated before they cause problems in the final display device, preventing image quality degradation.
Solution Approach 2:
The patent introduces an intermediary measurement structure that includes additional electrodes and voltage measurement circuits. These intermediary elements enable non-destructive detection of electrical short circuits by applying voltage through the OLED structure and measuring potential differences, allowing identification of defective OLEDs without damaging them.
2Reliability
If short circuits are detected early, then defective subpixels can be identified, but additional detection mechanisms and measurement processes are required
Solution Approach 1:
The patent designs the detection mechanism to serve multiple functions: it can detect short circuits in OLEDs, measure voltage changes across different OLED structures, and identify defective subpixels during both fabrication and post-shipment periods. This multi-functionality reduces the need for separate specialized detection systems for different detection scenarios.
Solution Approach 2:
The patent employs the OLED structure itself as part of the detection system by utilizing its inherent electrical properties and voltage characteristics. The OLED's own voltage response to applied electrical signals provides the detection basis, eliminating the need for completely separate external measurement apparatus and reducing overall system complexity.
3Measurement precision
If voltage measurement is performed on OLEDs, then short circuits can be detected, but the measurement process requires precise control of electrical conditions and timing
Solution Approach 1:
The patent implements feedback mechanisms where the measured voltage changes from the OLED structure are compared against reference values or thresholds. This feedback approach enables automatic identification of short circuits based on voltage deviations, simplifying the operation by eliminating the need for complex manual analysis of measurement data while maintaining high precision through automated comparison algorithms.
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
Enables effective detection and potential repair of short circuits in OLEDs, thereby maintaining image quality and extending the lifespan of organic light-emitting display devices.
Implementation Method 1
a sensor configured to measure a voltage of the reference voltage line
Data Source
AI summary
An organic light-emitting display device includes: an organic light-emitting display panel including: a plurality of subpixels including: an organic light-emitting diode (OLED), a driving transistor (DT) driving the OLED including a first transistor between a first node of the DT and a data line, and a second transistor (T2) between a second node of the DT and a reference voltage line having a reference voltage (RV) applied, a sensor, and a sampling switch, wherein, during an OLED short detection period for detecting a short circuit between the first electrode and a second electrode of the OLED: the DT and the first transistor are off, when the T2 is turned off, the RV line is initialized when the RV is applied thereto, after the T2 is turned on, the sampling switch is turned on to connect the sensor and the RV line, and the sensor measures the RV line voltage.