LCD Dot Inversion via Common Voltage Polarity Inversion
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Solution Overview
Problem
The dot inversion system in liquid crystal displays (LCDs) requires high voltage and a source driver with two types of polarities, leading to increased IC size and complexity, which complicates the design and reduces price competitiveness.
Innovation Solution
Implementing a line inversion type driving device with a common voltage generator and source driver that reverses polarity of the common voltage signal and synchronizes data signals to achieve a dot inversion system without increasing the IC size, using a shared data line configuration and shifting the output timing of the common voltage signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dot inversion system is implemented using conventional methods, then display quality is improved, but device complexity and IC size increase
Solution Approach 1:
The patent applies inversion by reversing the polarity relationship between common voltage and data signal. Instead of using a dedicated dot inversion driver with two types of polarities, the invention uses a line inversion type driver where the common voltage polarity is inverted relative to the data signal, thereby achieving dot inversion effect with simpler circuitry
Solution Approach 2:
The patent makes a line inversion type driving device perform the function of a dot inversion system by utilizing the shared data line configuration and polarity inversion technique. The same driving device structure serves multiple purposes: maintaining line inversion compatibility while achieving dot inversion display quality
2Measurement precision
If a dot inversion system is implemented using conventional methods, then display quality is improved, but IC size increases
Solution Approach 1:
The patent enables a line inversion type driving device to also achieve dot inversion functionality, allowing one IC to serve multiple purposes. This eliminates the need for separate dot inversion specific circuits, thereby maintaining IC size while achieving dot inversion display quality
Solution Approach 2:
By inverting the common voltage polarity and utilizing the shared data line configuration, the patent achieves dot inversion effect without requiring additional IC circuits designed specifically for dot inversion, thus keeping IC size compact
3Measurement precision
If high voltage is used in dot inversion system, then display quality is improved, but device complexity increases
Solution Approach 1:
The patent makes the line inversion type source driver capable of achieving dot inversion performance through polarity inversion technique. The same driver circuitry that generates line inversion signals is utilized to produce dot inversion effect, eliminating the need for complex high voltage generation circuits specific to dot inversion
Data Source
AI summary
A liquid crystal display (LCD) and a driving method thereof. The LCD includes: a liquid crystal panel which includes a plurality of pixels formed in intersection areas between a plurality of gate lines and a plurality of data lines, wherein a pair of adjacent pixels share the same data line and are located between a pair of gate lines; a common voltage generator which shifts and outputs a common voltage signal having a polarity, which is reversed one time for a period time and repeated consecutively two time for a ½ period time, for a predetermined time; and a source driver which synchronizes a data signal of a line inversion system with an output timing of the common voltage signal and outputs the data signal to an opposite polarity to a polarity of the common voltage signal to drive the plurality of pixels in a dot inversion system.