Foldable Screen Pulse Control for Split-Screen Brightness
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Solution Overview
Problem
The transition of a foldable screen from a folded to an unfolded state results in inconsistent brightness due to threshold voltage drift of transistors caused by a direct current bias in the gate driven on array (GOA) circuit, leading to a split-screen problem.
Innovation Solution
A display method that outputs pulse signals to control the threshold voltage of transistors within a preset range by alternately changing pulse signals on the second screen, while scanning and writing data voltages to sub-pixels to maintain consistent brightness across the unfolded screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a GOA signal in the GOA circuit is in a direct current (DC) bias state for a long time when the second screen displays no picture, then the second screen can be controlled to be blank, but the threshold voltage Vth of the transistor drifts causing split-screen brightness inconsistency
Solution Approach 1:
The patent applies periodic action by alternating between a second pulse signal and a third pulse signal in a periodic manner. The second pulse signal controls the transistor to maintain a stable threshold voltage, while the third pulse signal blanks the second screen. This periodic alternation prevents continuous DC bias on the transistor, thereby preventing threshold voltage drift while maintaining the blank display state of the second screen.
2Illumination intensity
If the second screen is controlled to be blank by continuous scanning, then the blank display is maintained, but power consumption increases
Solution Approach 1:
Instead of continuous scanning, the patent uses periodic scanning where the second screen is scanned only during specific periods when the third pulse signal is applied. During other periods, the screen remains blank without active scanning. This periodic operation significantly reduces power consumption while maintaining the blank display quality.
Solution Approach 2:
The patent extracts the scanning operation from a continuous process and applies it only when necessary. By separating the blanking function (third pulse signal) from the scanning function, the system can maintain the blank display state without continuously scanning, thereby reducing power consumption.
3Illumination intensity
If the first screen is scanned and written with data voltage, then the first screen displays correctly, but the threshold voltage drift affects the unfolded screen brightness consistency
Solution Approach 1:
The patent applies preliminary action by controlling the threshold voltage of the transistor on the second screen to remain stable within a preset range before the foldable screen transitions from folded to unfolded state. By maintaining the threshold voltage within the stable range during the folded state through periodic pulse signal alternation, the system ensures that when the screen is unfolded, the brightness remains consistent across both screens, preventing split-screen brightness inconsistency.
Data Source
AI summary
A display method for a foldable screen and an electronic device can resolve a split-screen problem that when a foldable screen of the electronic device transitions from a folded state to an unfolded state, brightness of the unfolded foldable screen is inconsistent. The method includes, outputting, in response to a transition of the foldable screen from the unfolded state to the folded state, a first pulse signal to a first screen, and outputting a second pulse signal and a third pulse signal that periodically and alternately change to a second screen. The second pulse signal and the third pulse signal that periodically and alternately change are used to control a threshold voltage of a transistor on the second screen to remain within a preset range.