TFT-LCD Common Voltage Adjustment Circuit Integration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional common voltage adjustment circuits for liquid crystal display panels require external components and manual adjustments, leading to increased costs and complexity, and can result in inaccurate display due to inappropriate DC and AC voltage settings.

Innovation Solution

A common voltage adjustment circuit integrated within the scan or data driver of a TFT-LCD panel, utilizing registers, digital-to-analog converters, and a regulator to adjust DC and AC voltage signals, with configuration controlled via an I2C bus, reducing external components and enabling precise voltage adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional adjustment circuit is disposed outside the TFT-LCD panel, then manual voltage adjustment is enabled, but the volume of the printed circuit board and the cost both increase

Engineering Contradiction:

Improvemanual voltage adjustmentVSAvoidexternal adjustment circuit

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent integrates the common voltage adjustment functionality directly into the scan driver chip. The register and digital-to-analog converter are incorporated within the chip structure, eliminating the need for separate external adjustment circuits. This merging of functions reduces the number of external components and simplifies the overall system architecture while maintaining the capability for voltage adjustment.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces manual mechanical adjustment (using external variable resistors) with automated digital control. A register stores DC voltage values and a digital-to-analog converter transforms digital signals to analog voltage outputs, enabling precise voltage adjustment through digital means rather than manual physical adjustment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If resistors must be adjusted manually, then voltage tuning is possible, but time spent and cost both increase

Engineering Contradiction:

Improvevoltage tuningVSAvoidadjustment time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical adjustment with automated digital control mechanisms. A register stores predefined DC voltage values and a digital-to-analog converter transforms digital control signals to analog voltage outputs, enabling rapid electronic adjustment without manual intervention. This substitution dramatically reduces adjustment time while maintaining precise voltage tuning capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent incorporates a register that stores multiple predefined DC voltage values in advance. This preliminary storage of voltage values allows the system to quickly switch between different voltage levels without requiring real-time manual calculation or adjustment, thereby reducing the time needed for voltage tuning.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If conventional adjustment circuit is used, then external components are required, but device complexity and cost increase

Engineering Contradiction:

Improveexternal component adjustmentVSAvoidexternal components

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

4Productivity

If inappropriate DC and AC voltage settings are used, then display can operate, but inaccurate display results occur

Engineering Contradiction:

Improvedisplay operationVSAvoiddisplay accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent incorporates a common voltage adjustment mechanism that enables precise control of DC and AC voltage components. By using a register to store accurate voltage values and a digital-to-analog converter to generate precise voltage signals, the system ensures accurate display results while maintaining operational productivity.

Inventive Principle:

Principle #23Feedback

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 solution reduces the need for external elements, enhances adjustment accuracy and speed, and ensures appropriate common voltage settings, preventing flicker and improving display quality.

Implementation Method 1

The first digital-to-analog converter, coupled to the first register, converts the received digital DC voltage value to a first value. The second digital-to-analog converter, coupled to the second register, converts the received digital AC voltage value to a second value.

Methodology Applied

Scientific EffectDigital-to-Analog Conversion:

Data Source

PatentUS7400312B2Common voltage adjustment circuit and liquid crystal display panel utilizing the same

Publication Date: 2008.07.15 AU OPTRONICS CORP

AI summary

A common voltage adjustment circuit. The common voltage adjustment circuit is applied in a liquid crystal display panel having a plurality of display units, coupled to a common electrode. The common voltage adjustment circuit has a first register, a second register, a first digital-to-analog converter, a second digital-to-analog converter, and a regulator. The common voltage adjustment circuit adjusts AC voltage and DC voltage of the common voltage and provides the adjusted common voltage to the common electrode.