OLED Burn-In Test Circuit Brightness Stabilization
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Solution Overview
Problem
During the burn-in test of OLED display devices, large brightness fluctuations occur, leading to color shift and degradation of the device's lifespan and quality.
Innovation Solution
A display panel with a burn-in test circuit comprising multiple pixel driving circuits, each including a data writing module, a driving module, a sensing module, a control module, and a light-emitting module, connected through thin film transistors and capacitors to stabilize the driving voltage and feedback current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a burn-in test is performed on the light-emitting device in the initial stage, then the device lifetime can be evaluated, but large brightness fluctuations occur causing color shift and quality degradation
Solution Approach 1:
The patent applies preliminary action by introducing a warm-up period before the burn-in test. During this warm-up stage, the light-emitting device is operated at reduced current for a predetermined time to allow stabilization of the organic light-emitting layer. Only after this preliminary stabilization phase is completed does the system proceed to the actual burn-in test, thereby preventing brightness fluctuations and color shift while still enabling reliable lifetime evaluation.
2Productivity
If high current density is applied during burn-in test to accelerate aging, then lifetime evaluation is improved, but brightness fluctuation and color shift worsen
Solution Approach 1:
The patent implements periodic action by dividing the burn-in test into multiple stages with different current densities. The test begins with a warm-up stage using lower current density for stabilization, followed by the main burn-in stage with higher current density for accelerated aging. This periodic variation in current density allows the device to stabilize before subjected to stress conditions, thereby maintaining brightness stability while still achieving efficient lifetime evaluation.
Data Source
AI summary
A display panel and a burn-in test method of the display panel are disclosed. The display panel includes a data writing module, a driving module, a sensing module, a control module, and a light-emitting module. Different devices are set in each module. When the display panel is subjected to a burn-in test, a high level signal is provided to the control module, thereby controlling a test current to flow to the light-emitting module. Thereby, an influence of high current on a test performance is improved, and a comprehensive performance of the display panel is improved.