Impulsive LCD Driving Reduces Charging Time
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Solution Overview
Problem
Conventional liquid crystal display (LCD) technologies face issues with image clarity due to slow response times of liquid crystal molecules, leading to unclear and blurred images, especially when polarity inversion increases charging time and reduces the time for reaching target luminance, and existing impulsive driving methods either increase costs or decrease normal image display time.
Innovation Solution
An impulsive driving method for LCDs that includes a plurality of gate lines and data lines transmitting gate-on and data voltages, with a signal controller determining the application time of impulsive data voltage based on a duty ratio selection signal, allowing for alternation between normal and impulsive data voltages within a horizontal period, and using a duty ratio selector and inversion selector to optimize voltage polarity and duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polarity inversion is applied to prevent image deterioration, then image quality is maintained, but charging time increases and target luminance is not reached
Solution Approach 1:
The patent applies periodic action by implementing impulsive driving that periodically inserts black images between normal images. The signal controller alternates between normal data voltages and impulsive data voltages in a periodic manner, creating a rhythm of normal display followed by brief black periods. This periodic impulsive driving allows the liquid crystal capacitor to discharge partially during black periods, reducing the charging time required during normal periods while maintaining overall image quality through the alternating pattern.
2Loss of time
If impulsive emission type driving is used to reduce charging time, then response time improves, but manufacturing cost increases due to additional inverters
Solution Approach 1:
The patent applies universality by making the data driver serve multiple functions. The data driver not only drives normal data voltages for image display but also generates and applies impulsive data voltages for black period insertion. The signal controller integrates the impulsive driving control within the existing data driver architecture, allowing one data driver to handle both normal and impulsive driving modes without requiring separate dedicated circuits for each function, thereby avoiding additional inverter requirements.
Solution Approach 2:
The patent merges the impulsive driving control functionality into the existing data driver and signal controller architecture. Instead of adding separate inverters or driving circuits for impulsive black period generation, the patent combines the normal data voltage driving and impulsive data voltage driving functions within the unified data driver system, controlled by the signal controller's integration of both driving modes in a single control framework.
3Loss of time
If cyclic resetting type driving is used to reduce charging time, then response time improves, but normal image display time decreases and frame memory is required
Solution Approach 1:
The patent applies partial action by inserting brief impulsive black periods that are shorter than the normal image display periods. The impulsive driving duration is controlled to be a small fraction of the total frame time, providing just enough discharge time to reduce charging requirements without significantly impacting the overall normal image display duration. This partial impulsive intervention achieves the charging time reduction goal while maintaining adequate normal display time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method improves image clarity by efficiently alternating between normal and impulsive data voltages, reducing charging time and maintaining target luminance without the need for additional frame memory or increased inverter usage, thus enhancing the overall display quality and reducing manufacturing costs.
Implementation Method 1
a liquid crystal (LC) layer having dielectric anisotropy, which is disposed between the two panels
Implementation Method 2
The LCD applies the voltages to the field generating electrodes to generate electric field to the liquid crystal layer, and the strength of the electric field can be controlled by adjusting the voltage across the liquid crystal capacitor. Since the electric field determine the orientations of liquid crystal molecules
Data Source
AI summary
A liquid crystal display is provided, which includes: groups of gate lines transmitting a gate-on voltage; data lines alternately transmitting normal data voltages and an impulsive data voltage; pixels arranged in a matrix and including switching elements that are connected to the gate lines and the data lines and turn on in response to the gate-on voltage to transmit the data voltages; gate driving circuits connected to respective groups of gate lines and sequentially applying the gate-on voltage to the gate lines; a data driver applying the data voltages to the data lines; a duty ratio selector outputting a duty ratio selection signal informing a selected duty ratio; and a signal controller controlling the gate driver and the data driver based on the duty ratio selection signal, wherein the signal controller determines a time for the application of the impulsive data voltage based on the duty ratio selection signal.