LTPO OLED Scan Timing Adjustment for Dark Band and Image Sticking
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Solution Overview
Problem
The dark band problem persists on low-temperature polycrystalline oxide (LTPO) organic light-emitting diode (OLED) panels under low luminance, due to insufficient compensation capabilities of existing methods and voltage offset issues, leading to image sticking and reduced reliability.
Innovation Solution
A method of controlling a display panel by adjusting the scan timing of the scan signal for the initial voltage of OLED pixels, without dynamically adjusting the initial voltage, thereby maintaining a constant cross-voltage and preventing image sticking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If dynamic adjustment of initial voltage is applied to solve the dark band problem, then the dark band problem is improved, but image sticking problems occur and reliability is reduced
Solution Approach 1:
The patent applies dynamics by making the scan timing adjustable rather than fixed. The scan timing is dynamically adjusted in different frame periods to disperse the voltage offset effect, transforming a static problematic timing into a dynamic controllable parameter that prevents dark bands without causing image sticking.
Solution Approach 2:
The patent implements periodic action by adjusting scan timing in alternating frame periods. The scan timing is modified in a periodic manner across different frames, creating a rhythm that disperses the voltage offset effect over time while maintaining stable cross-voltage and preventing image sticking.
2Measurement precision
If Demura method is applied to compensate for brightness difference, then brightness compensation is improved, but dark band problem cannot be completely solved
Solution Approach 1:
The patent applies preliminary action by adjusting the scan timing before the voltage offset can cause the dark band problem. By modifying the timing in advance and dispersing the offset effect proactively, the patent prevents the dark band from forming in the first place, rather than merely compensating for it after occurrence.
Solution Approach 2:
The patent converts the harmful voltage offset effect into a beneficial dispersion pattern. By strategically adjusting scan timing, the voltage offset that would normally cause dark bands is transformed into a dispersed temporal pattern that averages out the effect, converting a harmful concentrated offset into a beneficial distributed pattern.
3Stability of the object's composition
If initial voltage is output to anode to keep cross-voltage constant, then cross-voltage stability is improved, but dynamic compensation cannot control anode voltage to track cathode voltage
Solution Approach 1:
The patent applies dynamics by making the scan timing adjustable rather than fixed. The scan timing is dynamically adjusted in different frame periods to disperse the voltage offset effect, transforming a static problematic timing into a dynamic controllable parameter that prevents dark bands without causing image sticking.
Solution Approach 2:
The patent implements periodic action by adjusting scan timing in alternating frame periods. The scan timing is modified in a periodic manner across different frames, creating a rhythm that disperses the voltage offset effect over time while maintaining stable cross-voltage and preventing image sticking.
Data Source
AI summary
A method of controlling a display panel comprising a plurality of pixels includes a step of outputting a scan control signal to the display panel in a plurality of frame periods. The scan control signal has a first timing setting in a first frame period among the plurality of frame periods, and has a second timing setting in a second frame period among the plurality of frame periods, wherein the second timing setting is different from the first timing setting. A plurality of scan signals generated from the scan control signal are output to the plurality of pixels respectively and sequentially.