Compensating Frames for LCD Flicker Reduction
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Solution Overview
Problem
Liquid crystal display (LCD) panels experience flicker when the driving frequency is changed from high to low or vice versa, leading to deteriorated display quality due to the residual DC effect on the common voltage, causing luminance inconsistencies.
Innovation Solution
The implementation of intermediate frequency compensating frames, which are shorter frames inserted between frequency changes, help stabilize the common voltage, ensuring symmetrical increases and decreases, thus minimizing flicker and maintaining consistent luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the driving frequency is changed from high to low or vice versa to adjust power consumption, then power consumption is optimized, but flicker is generated and display quality deteriorates
Solution Approach 1:
The patent applies preliminary action by inserting an intermediate frequency compensating frame before the actual frequency change occurs. This compensating frame pre-adjusts the common voltage to account for the upcoming frequency transition, ensuring that the voltage remains stable and symmetric during the change. By performing this preparatory adjustment, the patent prevents flicker from occurring in the first place rather than correcting it after it appears.
Solution Approach 2:
The patent uses an intermediate frequency compensating frame as a mediator between the high and low driving frequencies. This intermediate frame acts as a buffer that smooths the transition by adjusting the common voltage to a compensating level that maintains symmetry. The intermediary frame ensures that the voltage waveform remains balanced during frequency transitions, thereby preventing flicker while still allowing power consumption optimization.
2Use of energy by moving object
If the driving frequency is changed to optimize power consumption, then energy efficiency is improved, but residual DC effect on common voltage causes luminance inconsistencies
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the common voltage level based on the driving frequency transitions. When transitioning between high and low frequencies, the patent modifies the voltage parameter by inserting an intermediate frequency compensating frame with a specific voltage level that differs from both the high and low frequency states. This parameter adjustment ensures that the common voltage maintains proper symmetry and prevents residual DC effects that would cause luminance inconsistencies.
3Device complexity
If frequency transition is performed directly without compensation, then device complexity is reduced, but flicker occurs and display quality deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the frequency transition process into distinct segments: a high frequency state, an intermediate frequency compensating frame state, and a low frequency state (or vice versa). Instead of making a direct transition from high to low frequency, the patent inserts the intermediate compensating frame as a separate segment in between. This segmentation allows each state to be controlled independently, ensuring proper voltage symmetry while maintaining relatively simple overall control logic.
Data Source
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AI summary
A method of driving a display panel (100) includes generating a first driving period having a first driving frequency, generating a second driving period having a second driving frequency, and inserting a compensating frame(CF1, CF2) between the first driving period and the second driving period. A display apparatus includes a display panel (100) configured to display an image, and a display panel driver configured to generate a first driving period having a first driving frequency, to generate a second driving period having a second driving frequency, and to insert a compensating frame (CF1, CF2)between the first driving period and the second driving period.