Display Voltage Ripple Compensation via Feedback
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Solution Overview
Problem
Liquid crystal displays experience image quality deterioration due to crosstalk caused by ripples in the common voltage, which occurs when the data voltages rise or fall, affecting the liquid crystal capacitor and leading to image degradation.
Innovation Solution
A display apparatus that includes a data driver, a gate driver, a display panel with data and gate lines, a voltage generator for common and storage voltages, and a voltage compensator that receives the storage voltage feedback to generate a compensation signal to counteract the ripple in the common voltage, thereby improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If inversion driving scheme is adopted to prevent liquid crystal deterioration, then liquid crystal longevity is improved, but ripple occurs in common voltage causing crosstalk and image quality deterioration
Solution Approach 1:
The patent introduces a feedback mechanism where the storage voltage from the liquid crystal capacitor is fed back to the common voltage generator. This feedback loop enables the common voltage generator to detect ripples caused by data voltage transitions and automatically adjust the common voltage to compensate for these ripples, thereby eliminating crosstalk while maintaining the inversion driving scheme's protective effect on liquid crystal longevity.
2Ease of operation
If common voltage is applied as direct current voltage, then liquid crystal orientation control is simplified, but ripple occurs when data voltages change causing crosstalk
Solution Approach 1:
The patent transforms the static common voltage into a dynamic voltage that can automatically adjust in response to changing conditions. The common voltage generator changes from simply applying a fixed DC voltage to actively monitoring storage voltage feedback and dynamically adjusting the common voltage level to compensate for ripples caused by data voltage transitions, thus maintaining ease of operation while improving image quality.
3Productivity
If data voltages are applied through data lines to pixels, then image display functionality is achieved, but ripple in common voltage exerts influence on liquid crystal capacitor causing crosstalk
Solution Approach 1:
The patent introduces storage voltage feedback as an intermediary mechanism between the data voltage application process and the common voltage control. The storage voltage, which reflects the actual voltage state of the liquid crystal capacitor including ripple effects, serves as a mediator that carries information about harmful ripples back to the common voltage generator, enabling targeted compensation without disrupting normal image display functionality.
Data Source
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AI summary
A display apparatus includes; a data driver integrated in one chip and which outputs data signals; a gate driver which sequentially outputs gate signals, a display panel which includes; a plurality of data lines which receive the data signals, a plurality of gate lines which receive the gate signals, and a plurality of pixels connected to a corresponding gate line and a corresponding data line, a voltage generator which generates a common voltage and a storage voltage and provides them to the display panel, and a voltage compensator which receives the storage voltage fedback from the display panel and generates a compensation signal, wherein the display panel further includes a feedback line which provides the voltage compensator with the storage voltage, and wherein the feedback line is electrically connected to the voltage compensator through the data driver.