Display Device Power Reduction via Dynamic Frequency and Luminance Control

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Solution Overview

Problem

Display devices in mobile devices face challenges in reducing power consumption while maintaining picture quality, as lowering driving frequency can lead to motion blur, afterimage, and flicker, which degrade image quality.

Innovation Solution

A display device and method that operate at a low frequency, where the timing controller gradually changes luminance and optionally adjusts the size or color of images or text, and increases luminance upon touch input, allowing for reduced power consumption without flicker issues, by selecting a low frequency such as 0Hz to 3Hz for Always On Display images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If driving frequency is reduced to reduce power consumption, then power consumption is reduced, but picture quality deteriorates due to motion blur, afterimage and flicker

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

Solution Approach 1:

The patent applies dynamics by making the driving frequency variable rather than fixed. The display device dynamically adjusts the driving frequency based on the type of content being displayed: using low frequency (0Hz to 3Hz) for static images to save power, and high frequency (60Hz or higher) for moving images to maintain picture quality. This dynamic adaptation resolves the contradiction between power consumption and picture quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the driving frequency parameter based on content characteristics. By detecting whether the displayed content is static or moving, the system adjusts the frequency parameter accordingly - maintaining high frequency for moving content to prevent motion blur and afterimage, while using low frequency for static content to reduce power consumption without causing flicker.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If driving frequency is reduced to reduce power consumption, then power consumption is reduced, but flicker occurs which degrades image quality

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

Solution Approach 1:

The patent changes the driving frequency parameter based on content characteristics. By detecting whether the displayed content is static or moving, the system adjusts the frequency parameter accordingly - maintaining high frequency for moving content to prevent motion blur and afterimage, while using low frequency for static content to reduce power consumption without causing flicker.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3133585B1Display device having reduced power consumption and driving method therefor
Publication Date: 2020.01.01 SAMSUNG DISPLAY CO LTD
  • EP3133585B1 patent drawingFigure 1~2
  • EP3133585B1 patent drawingFigure 3~4
  • EP3133585B1 patent drawingFigure 5~6

AI summary

A display device may include a display panel, a data driver transmitting a data signal, a scan driver sequentially transmitting a scan signal, a frequency selector for selecting a driving frequency for image display, selecting a low frequency if the image displayed on the display panel is a first image and selecting a normal frequency if the image displayed on the display panel is not the first image, the normal frequency being higher than the low frequency. The display device also includes a timing controller for controlling the data driver and the scan driver based on the selected driving frequency. The timing controller may control the data driver and the scan driver such that luminance of the display panel on which the first image is displayed is periodically changed according to the low frequency if the image displayed on the display panel is the first image.