Liquid Crystal Display Flicker Suppression via Segmented Counter Voltage
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Solution Overview
Problem
Liquid crystal display devices performing low-frequency driving experience flicker issues due to variations in optimum counter voltage across the display unit, particularly at the peripheral areas, and existing solutions are limited in fine-tuning adjustments across multiple image areas, leading to visible boundaries and inadequate flicker suppression.
Innovation Solution
A liquid crystal display device with a gradation correction system that includes a correction value storage part and conversion tables to adjust voltage values for each pixel, ensuring equal charging rates for positive and negative polarities, thereby minimizing flicker by applying optimized counter voltages uniformly across the display unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If low-frequency driving is employed to reduce power consumption, then power consumption is reduced, but flicker becomes visually recognizable due to long polarity reversal cycles
Solution Approach 1:
The invention changes the parameter of common electrode voltage by introducing counter adjustment that equalizes charging rates between positive and negative polarity write operations. This parameter modification compensates for the long polarity reversal cycles in low-frequency driving, making flicker invisible to human eyes while maintaining the power savings benefits of low-frequency driving.
2Object-affected harmful factors
If counter adjustment is performed to suppress flicker, then flicker is suppressed, but visible boundaries appear between different image areas due to limited fine-tuning capability
Solution Approach 1:
The invention segments the display unit into multiple image areas (e.g., four quadrants) and performs independent counter adjustments for each area. This segmentation enables fine-tuned optimization of counter voltage in each region, eliminating visible boundaries while suppressing flicker uniformly across the entire display.
Solution Approach 2:
The invention applies local quality by allowing different common electrode voltages to be applied to different image areas according to their specific requirements. Each area receives customized counter adjustment tailored to its local characteristics, achieving uniform flicker suppression without visible boundaries while maintaining overall system simplicity.
3Object-affected harmful factors
If different common electrode voltages are applied to different image areas to suppress flicker, then flicker is suppressed, but device complexity increases
Solution Approach 1:
The invention divides the display into manageable image areas and implements independent counter adjustment for each segment. This segmentation approach enables effective flicker suppression through localized voltage optimization while keeping the overall control system relatively simple and modular, avoiding excessive complexity.
Data Source
AI summary
The occurrence of flicker is effectively suppressed particularly in a liquid crystal display device that performs low-frequency driving.Provided are a gradation-to-voltage value conversion table for converting a gradation to a voltage value, a correction value map for storing a correction value, and a voltage value-to-gradation conversion table for converting a voltage value to a gradation. A gradation of an input image signal is converted to a first voltage value, using the gradation-to-voltage value conversion table. The correction value specified in accordance with a location of a pixel to be processed is added to or subtracted from the first voltage value so that a second voltage value is obtained. The second voltage value is converted to an output gradation, using the voltage value-to-gradation conversion table. A driving video signal is applied to a source bus line, based on the output gradation.