Display Control Device Adaptive Refresh Rate Flicker Management

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Solution Overview

Problem

Liquid crystal display panels using CG silicon TFTs or amorphous silicon TFTs can only lower their refresh rate to 50 Hz while maintaining display quality, and oxide semiconductor panels with slow response speed face issues with flicker recognition due to non-uniform pixel capacitances and electric charge leakage, which existing techniques fail to address effectively.

Innovation Solution

A control device and method that determine whether grayscale levels of pixels fall within a specific range, adjusting the refresh rate accordingly to prevent flicker recognition, allowing for reduced power consumption while maintaining image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the refresh rate is lowered to reduce power consumption, then power consumption is reduced, but flicker becomes easily recognized due to slow liquid crystal response speed and non-uniform pixel capacitances

Engineering Contradiction:
Improvepower consumptionVSAvoidflicker recognition
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the refresh rate based on the grayscale levels being displayed. When intermediate grayscale levels (which are more susceptible to flicker) are detected, the refresh rate is increased to suppress flicker perception. When extreme grayscale levels are displayed, the refresh rate can be lowered to reduce power consumption. This conditional parameter adjustment resolves the contradiction between power savings and flicker suppression.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the refresh rate is lowered below 50 Hz, then power consumption is reduced, but display quality deteriorates due to visible flicker and non-uniform pixel potential changes

Engineering Contradiction:
Improvepower consumptionVSAvoiddisplay quality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent dynamically changes the refresh rate parameter based on the displayed grayscale levels. By detecting when intermediate grayscale levels are present (which cause non-uniform pixel potential changes and visible flicker), the system increases the refresh rate to maintain display quality. When only extreme grayscale levels are displayed, the refresh rate can be reduced to save power. This conditional parameter adjustment resolves the contradiction between power consumption and display quality reliability.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a fixed refresh rate is used, then control is simple, but power consumption cannot be optimized for different display conditions

Engineering Contradiction:
Improvecontrol simplicityVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent transitions from a static fixed refresh rate to a dynamic adaptive refresh rate system. The refresh rate automatically adjusts based on the grayscale levels being displayed, increasing when intermediate grayscales are present (to prevent flicker) and decreasing when extreme grayscales are displayed (to save power). This dynamic adaptation resolves the contradiction between control simplicity and power consumption optimization.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2924682B1Control device, display device, and display device control method
Publication Date: 2019.12.18 SHARP KK
  • EP2924682B1 patent drawingFigure 1
  • EP2924682B1 patent drawingFigure 2~3(c)
  • EP2924682B1 patent drawingFigure 4(a)~5

AI summary

A display device that suppresses electric power consumption and displays an image with excellent quality is to be realized. A host control section (30) in accordance with an aspect of the present invention is a control device for a display device (1), said control device includes: an image determining section (35) for determining whether or not grayscale levels of a plurality of pixels in an image fall within a first range which consists of intermediate grayscale levels; and a driving changing section (36) for changing, according to a result of the determining carried out by the image determining section (35), a refresh rate of the display device (1).