Gate Voltage Control for LCD Driver Stability

Solution Overview

Problem

In liquid crystal displays, the application of gate high voltage before gate low voltage can cause damage to the gate driver, leading to defects due to the lack of a controlled voltage sequence.

Innovation Solution

A gate voltage controlling apparatus and method that generates and applies gate voltages in a sequence from lower to higher voltage levels, using a power supply, gate driver, and gate voltage control means to delay the higher voltage and minimize defects in the gate driver.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gate high voltage is applied before gate low voltage, then the gate driver may be damaged, but applying voltages without sequence control simplifies the voltage control mechanism

Engineering Contradiction:

Improvegate driver reliabilityVSAvoidvoltage control sequence complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The gate low voltage is applied preliminarily before the gate high voltage to prepare the gate driver for subsequent high voltage operation. This preliminary action prevents damage by ensuring the driver is in a safe state before exposure to high voltage, resolving the contradiction between reliability and control complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A voltage control mechanism acts as an intermediary between the power supply and gate driver, managing the sequence of voltage application. This intermediary component enables reliable sequential control without significantly increasing overall system complexity, as it integrates into the existing power supply architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If gate voltages are applied without sequence control, then the control mechanism is simpler, but defects in the gate driver increase

Engineering Contradiction:

Improvevoltage control mechanism complexityVSAvoidgate driver defects

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The gate low voltage is applied preliminarily before the gate high voltage to prepare the gate driver for subsequent high voltage operation. This preliminary action prevents damage by ensuring the driver is in a safe state before exposure to high voltage, resolving the contradiction between reliability and control complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A voltage control mechanism acts as an intermediary between the power supply and gate driver, managing the sequence of voltage application. This intermediary component enables reliable sequential control without significantly increasing overall system complexity, as it integrates into the existing power supply architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7764257B2Apparatus and method for controlling gate voltage of liquid crystal display

Publication Date: 2010.07.27 LG DISPLAY CO LTD

AI summary

Gate voltage controlling apparatus and method wherein a gate voltage may be applied to a gate driver sequentially from a lower voltage toward a higher voltage to stably drive and protect the gate driver, thereby minimizing any defects in the gate driver. In the gate controlling apparatus, a power supply generates at least two gate voltages having a different voltage level. A gate driver generates a scanning pulse that selects a display line using the at least two gate voltages having a different voltage level. A gate voltage controller supplies the gate voltages to the gate driver in sequence from a lower voltage toward a higher voltage.