OLED Display Inspection Using Segmented Signal Wave and Camera Detection
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Solution Overview
Problem
In organic light emitting display devices, detecting shorts between the first power source and the light emission control line is challenging, especially in large high-resolution panels, leading to increased inspection time and decreased production yield due to the need for camera-based inspections of every pixel.
Innovation Solution
An organic light emitting display device and method that involves a scan driver supplying scan signals and light emission control signals, a data driver supplying inspection data signals in synchronization, and a first power source providing different voltages during inspection and operation periods, allowing for line-by-line detection of defects and repair of shorts between the light emission control lines and the first power source using signal waves and a camera only for defective lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If camera-based inspection is used to detect shorts between the first power source and light emission control line, then detection capability is improved, but inspection time increases significantly
Solution Approach 1:
The inspection process is segmented into two stages: first, a rapid signal wave-based inspection is performed on all pixels to identify potentially defective lines; second, camera-based inspection is applied only to the specific lines identified as defective in the first stage. This segmentation reduces overall inspection time while maintaining detection capability.
Solution Approach 2:
The inspection method applies different inspection qualities to different regions: signal wave inspection with lower detection capability but high speed is applied globally to all lines, while camera inspection with high detection capability but low speed is applied locally only to defective lines identified by the signal wave method.
2Measurement precision
If camera inspection is applied to every pixel in large high-resolution panels, then detection accuracy is improved, but production yield decreases due to increased inspection time
Solution Approach 1:
The pixel array is segmented into groups based on line membership, and the inspection process is segmented into two phases: rapid signal wave screening followed by targeted camera inspection of only those lines containing defective pixels, thereby improving productivity while maintaining detection accuracy.
Solution Approach 2:
Instead of applying full camera inspection to all pixels (excessive action), the method applies partial inspection using signal waves to all lines and reserves camera inspection only for lines with detected defects, achieving sufficient detection accuracy with reduced time loss.
3Speed
If signal waves are used for inspection, then inspection speed is improved, but ability to detect shorts between first power source and light emission control line deteriorates
Solution Approach 1:
The inspection methodology is segmented into two complementary approaches: signal wave inspection that provides high speed but limited detection capability, and camera inspection that provides high detection capability but lower speed. The segmented application of both methods resolves the contradiction.
Solution Approach 2:
The patent merges two different inspection methods (signal wave inspection and camera inspection) into a unified two-stage process, where each method compensates for the other's weaknesses, achieving both high speed and high detection accuracy.
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
This approach significantly reduces inspection time by allowing line-by-line detection and repair of defects, thereby shortening the inspection period and increasing production yield, especially for large high-resolution panels.
Implementation Method 1
the pixels generate light having a brightness (e.g., a predetermined brightness) by controlling an amount of current flowing from a first power source to a second power source through an organic light emitting diode (OLED)
Implementation Method 2
a first power source supply configured to supply a first voltage as the first power source during the inspection period and to supply a second voltage as the first power source during an other suitable period, the second voltage being higher than the first voltage
Data Source
AI summary
An organic light emitting display device including pixels positioned in regions defined by scan lines and light emission control lines extending in a first direction, and data lines extending in a second direction different from the first direction, the pixels being configured to control an amount of current flowing from a first power source to a second power source by way of organic light emitting diodes (OLEDs) in response to data signals, organic light emitting display device includes a scan driver configured to sequentially supply scan signals to the scan lines and light emission control signals to the light emission control lines during an inspection period, and a data driver configured to supply inspection data signals to the data lines in synchronization with the scan signals during the inspection period.