LCD Drive IC Control Register Self-Refreshing

Solution Overview

Problem

Conventional LCD drive ICs are prone to errors and malfunctions due to external noise such as electrostatic discharge (ESD) and electromagnetic interference (EMI, which require periodic refreshing by an outside host chip, leading to reduced lifespan and increased power consumption.

Innovation Solution

An LCD drive IC with a method to automatically recover bit values of the control register using an inner module, where command data is stored in a portion of the graphic RAM and refreshed during scanning operations, eliminating the need for an outside host chip and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the control register is periodically refreshed by an outside host chip, then the reliability of the LCD drive IC is improved, but the lifespan of the host chip is shortened and power consumption is increased

Engineering Contradiction:

Improvecontrol register data integrityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The LCD drive IC performs self-refreshing of the control register by utilizing its own internal resources (GRAM and scanning operation) instead of relying on an external host chip. The command data is automatically copied from GRAM to the control register during normal scanning operations, enabling the system to maintain itself without external intervention.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The GRAM is used for dual purposes: storing image data for display and storing command data for control register refreshing. The scanning operation that was originally designed only for image data transmission is extended to also transfer command data, making the existing infrastructure serve multiple functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If the control register is periodically refreshed by an outside host chip, then the reliability of the LCD drive IC is improved, but the lifespan of the host chip is shortened

Engineering Contradiction:

Improvecontrol register data integrityVSAvoidhost chip lifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The LCD drive IC performs self-refreshing of the control register by utilizing its own internal resources (GRAM and scanning operation) instead of relying on an external host chip. The command data is automatically copied from GRAM to the control register during normal scanning operations, enabling the system to maintain itself without external intervention.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The refreshing function is extracted from the external host chip and transferred to the internal GRAM and scanning operation of the LCD drive IC. This removes the burden from the host chip, allowing it to focus on its primary function of providing image data, thereby extending its lifespan.

Inventive Principle:

Principle #2Taking out (Extraction)

3Use of energy by moving object

If command data is stored in a portion of the GRAM and refreshed during scanning operations, then the power consumption is reduced, but the device complexity increases

Engineering Contradiction:

Improvepower consumptionVSAvoiddata storage and refreshing mechanism

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The GRAM is used for dual purposes: storing image data for display and storing command data for control register refreshing. The scanning operation that was originally designed only for image data transmission is extended to also transfer command data, making the existing infrastructure serve multiple functions without adding significant complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The command data storage function is merged with the image data storage function in the GRAM. The refreshing operation is merged with the existing scanning operation, combining multiple functions into unified processes that reduce overall system complexity despite the enhanced functionality.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS8120599B2Method of automatically recovering bit values of control register and LCD drive integrated circuit for performing the same

Publication Date: 2012.02.21 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of automatically recovering bit values of a control register includes storing command data inputted from a host in the control register and a portion of a graphic RAM (GRAM), and while a scanning operation is performed by the GRAM, outputting the command data stored in the GRAM to the control register and refreshing the control register.