LCD Source Driver Switch Modules for High-Voltage Range Handling

Solution Overview

Problem

Conventional switch devices for liquid crystal displays require high-voltage switches due to voltage ranges exceeding the maximum acceptable limits of middle-voltage switches, resulting in large size and high costs.

Innovation Solution

A switch device comprising semiconductor switches and voltage sources connected through nodes, allowing for efficient operation with smaller switches by managing voltage levels across multiple switch modules to achieve the same performance as conventional devices, supporting both AC and DC common voltage operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-voltage switches are used to handle voltage ranges up to six volts, then the switch device can operate within the maximum acceptable voltage limit, but the size of the switch device becomes large and the cost increases

Engineering Contradiction:

Improvevoltage handling capabilityVSAvoidswitch device size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The switch device is divided into multiple switch modules (first switch module with first and second semiconductor switches, second switch module with third and fourth semiconductor switches). Each module handles a portion of the voltage range, allowing middle-voltage switches to be used instead of a single high-voltage switch, thereby reducing overall device size while maintaining the ability to handle six-volt ranges.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An inverter circuit is introduced as an intermediary component between the switch modules. The inverter converts voltage levels to enable middle-voltage switches to operate correctly when exposed to higher voltage differences, allowing the use of smaller switches without compromising voltage handling capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If high-voltage switches are used to ensure the switch device can handle maximum voltage of six volts, then the voltage handling requirement is met, but the manufacturing cost becomes high

Engineering Contradiction:

Improvevoltage handling capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The switch device is divided into multiple switch modules (first switch module with first and second semiconductor switches, second switch module with third and fourth semiconductor switches). Each module handles a portion of the voltage range, allowing middle-voltage switches to be used instead of a single high-voltage switch, thereby reducing overall device size while maintaining the ability to handle six-volt ranges.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention replaces expensive high-voltage switches with multiple cheaper middle-voltage switches arranged in modular configurations. While individual middle-voltage switches have shorter voltage tolerance limits, their combined operation through the inverter system achieves the required six-volt handling capability at lower cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Area of stationary object

If middle-voltage switches are used to reduce size, then the switch device size decreases, but the voltage range exceeds the maximum acceptable limit of middle-voltage switches

Engineering Contradiction:

Improveswitch device sizeVSAvoidvoltage handling capability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The switch device is divided into multiple switch modules (first switch module with first and second semiconductor switches, second switch module with third and fourth semiconductor switches). Each module handles a portion of the voltage range, allowing middle-voltage switches to be used instead of a single high-voltage switch, thereby reducing overall device size while maintaining the ability to handle six-volt ranges.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An inverter circuit is introduced as an intermediary component between the switch modules. The inverter converts voltage levels to enable middle-voltage switches to operate correctly when exposed to higher voltage differences, allowing the use of smaller switches without compromising voltage handling capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8432386B2Switch device for source driver of liquid crystal display and operating method thereof

Publication Date: 2013.04.30 HIMAX TECH LTD

AI summary

A switch device for source drivers of liquid crystal displays includes a first switch module; a first switch; a second switch; a second switch module; a third switch module; a fourth switch module; a third switch; and a fourth switch; wherein when a first driving signal with a voltage level between a first voltage level and a second voltage level through the second switch module is sent to a second output terminal and a second driving signal with a voltage level between a third voltage level and a fourth voltage level through the third switch module is sent to a first output terminal, the first switch is turned on such that a first node is connected to a first voltage source with the first voltage level and the fourth switch is turned on such that a second node is connected to a fourth voltage source with the fourth voltage level.