Display Device Multiplexer Time-Divided Voltage Distribution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing display devices require multiple source driver integrated circuits (ICs) and consume high power, especially when displaying single colors, due to the high switching frequency of multiplexers in RGBW type displays.

Innovation Solution

The display device employs a multiplexer that time-divides data voltage output from source driver ICs, distributing it to data lines in a non-sequential manner, with control signals in antiphase, and extends the data switching cycle to N horizontal periods (where N is between 4 and 8), reducing the number of source driver ICs and power consumption by maintaining data voltage polarity during one frame period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a multiplexer is installed between the source driver IC and the data lines to reduce the number of source driver ICs, then the device complexity is reduced, but the power consumption increases when high switching frequency is generated and single color is displayed

Engineering Contradiction:
Improvenumber of source driver ICsVSAvoidpower consumption of multiplexer
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by implementing a data voltage polarity reverse cycle that repeats every three or more scan periods. The multiplexer switches between first and second scan orders in a periodic manner, where the number of charge and discharge cycles is controlled to be a multiple of three. This periodic switching pattern reduces the switching frequency and consequently the power consumption of the multiplexer while maintaining the functionality of reducing source driver IC count.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements dynamics by making the scan order switchable between first and second patterns based on display content requirements. The system dynamically adjusts the scan order and switching frequency of the multiplexer according to whether single color or multi-color display is needed, thereby optimizing power consumption while maintaining device complexity reduction benefits.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the number of charge and discharge data signal is maximized to improve display quality, then the image quality is improved, but the power consumption of the multiplexer increases

Engineering Contradiction:
Improveimage qualityVSAvoidpower consumption of multiplexer
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by controlling the number of charge and discharge cycles of the data signal to be a multiple of three (3, 6, 9, etc.) rather than using maximum possible cycles. This specific parameter modification reduces the switching frequency and power consumption while maintaining sufficient image quality through the periodic polarity reversal mechanism that ensures proper data voltage delivery to all pixel rows.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2998955B1Display device
Publication Date: 2019.04.24 LG DISPLAY CO LTD
  • EP2998955B1 patent drawingFigure 1
  • EP2998955B1 patent drawingFigure 2
  • EP2998955B1 patent drawingFigure 3A

AI summary

A display device includes a pixel array having a plurality of pixels arranged in a matrix form based on a crossing structure of data lines and gate lines, a data driver having a plurality of output channels and configured to output a data voltage, a multiplexer configured to distribute the data voltage output from the data driver to the data lines in response to first and second control signals, and a gate driver configured to output a gate pulse synchronized with the data voltage in a non-sequential manner. The first and second control signals are in antiphase, and a switching cycle of the first and second control signals is one horizontal period or two horizontal periods.