Common Voltage Regulating Circuit for Display Panel Power-On Afterimage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large-sized liquid crystal display panels experience power-on afterimages and power-off vertical blocks due to voltage differences between common and pixel electrodes, leading to poor display effects.
Innovation Solution
A common voltage regulating circuit and method that includes a first regulating sub-circuit to synchronize common and pixel electrode signals during power-on and a second regulating sub-circuit to manage voltage differences during power-off, using an identification sub-circuit to determine the power-off stage and regulate signals until a safe voltage difference is achieved.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the display panel is powered on with traditional circuit, then the display panel can be activated, but power-on afterimage occurs due to voltage difference between common and pixel electrodes
Solution Approach 1:
The first regulating sub-circuit is configured to provide a signal from the second signal input terminal (pixel electrode signal) to the first signal output terminal (common electrode) under the control of the enable signal terminal during the power-on stage. This preliminary action equalizes the voltage between common and pixel electrodes before normal display operation begins, preventing the power-on afterimage effect.
2Reliability
If the display panel is powered off with traditional circuit, then the display panel can be deactivated, but power-off vertical blocks occur due to voltage difference between common and pixel electrodes
Solution Approach 1:
The second regulating sub-circuit uses feedback control to regulate the common electrode signal during power-off stage. It compares the common electrode signal with the pixel electrode signal and adjusts the common electrode voltage to maintain a safe voltage difference, preventing power-off vertical blocks.
Solution Approach 2:
The circuit dynamically changes the voltage parameters of the common electrode based on the operating stage. During power-off, the second regulating sub-circuit adjusts the common electrode voltage to maintain an appropriate voltage difference with the pixel electrode, preventing display artifacts while ensuring proper panel shutdown.
3Reliability
If a regulating circuit is added to eliminate power-on afterimage and power-off vertical blocks, then display effect is improved, but device complexity increases
Solution Approach 1:
The common voltage regulating circuit performs multiple functions: during power-on stage, the first regulating sub-circuit equalizes voltages to prevent afterimages; during power-off stage, the second regulating sub-circuit maintains safe voltage differences to prevent vertical blocks; during normal display, it provides standard common electrode signals. This multi-functionality reduces the need for separate dedicated circuits for each function.
Data Source
AI summary
The present disclosure provides a common voltage regulating circuit and a common voltage regulating method, a display driving circuit and a display device, the common voltage regulating circuit is applied to a display panel, and the display panel includes a pixel electrode and a common electrode, the common voltage regulating circuit includes: a first regulating sub-circuit configured to provide a signal from a second signal input terminal to a first signal output terminal under the control of an enabling signal terminal in a power-on stage of the display panel; the first signal input terminal is configured to input a signal to be provided to the common electrode in a display stage of the display panel, the second signal input terminal is configured to input a signal to be provided to the pixel electrode in the power-on stage, the first signal output terminal is coupled with the common electrode.