Liquid Crystal Display Refresh Rate Control for Power Optimization

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Solution Overview

Problem

Current methods for reducing power consumption in terminals, such as liquid crystal displays, are inadequate as they primarily focus on decreasing backlight power without effectively addressing the overall power consumption of the liquid crystal panel and display chip.

Innovation Solution

A method that dynamically adjusts the refresh rate of liquid crystal display rows based on pixel grayscale values, setting a lower refresh rate for darker rows and a higher rate for brighter rows, thereby optimizing power usage without compromising visual quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the refresh rate of the liquid crystal panel is decreased to reduce power consumption, then power consumption is reduced, but image quality deteriorates due to visible flicker and motion blur

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

Solution Approach 1:

The liquid crystal panel is divided into multiple scanning zones (first scanning zone and second scanning zone) with different refresh rates. The first scanning zone displays static content at a lower refresh rate while the second scanning zone displays dynamic content at a higher refresh rate, allowing differential power management across different regions of the display

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The refresh rate is made dynamic and adaptive rather than uniform. The system dynamically adjusts the refresh rate of different scanning zones based on content characteristics (static vs. dynamic), transitioning between high and low refresh rates to optimize the balance between power consumption and image quality

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If the refresh rate is uniformly reduced across the entire display, then power consumption is reduced, but flicker and motion blur occur in dynamic content areas

Engineering Contradiction:
Improvepower consumptionVSAvoidflicker and motion blur
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

Different regions of the display (scanning zones) are assigned different refresh rates based on their local content characteristics. The first scanning zone operating at a first refresh rate and the second scanning zone operating at a second refresh rate allow each local area to have optimized quality appropriate to its content type

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system generates a virtual image frame that copies and merges content from different source frames. The virtual image frame is constructed by copying static content from a lower refresh rate frame and dynamic content from a higher refresh rate frame, then merging them to create a composite image that maintains quality while reducing overall power consumption

Inventive Principle:
Principle #26Copying

3Reliability

If the refresh rate is increased to maintain image quality, then visual performance is improved, but power consumption increases

Engineering Contradiction:
Improveimage qualityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The display is segmented into multiple scanning zones with different refresh rates, allowing the system to apply high refresh rates only where necessary (dynamic content areas) and low refresh rates in areas where quality is less critical (static content areas), thereby reducing overall power consumption while maintaining image quality where needed

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the refresh rate parameter dynamically based on content characteristics and display conditions. By adjusting the refresh rate parameter of different scanning zones according to their content type (static vs. dynamic), the system optimizes the balance between image quality and power consumption

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3168837B1Liquid crystal display method and device, computer program and recording medium
Publication Date: 2020.06.03 XIAOMI INC
  • EP3168837B1 patent drawingFigure 1~2
  • EP3168837B1 patent drawingFigure 3~4
  • EP3168837B1 patent drawingFigure 5~6

AI summary

The present disclosure discloses a liquid crystal display method and device, a computer program and a recording medium, and it relates to the filed of liquid crystal display. The method comprises: acquiring a grayscale value of each pixel in each row in a displayed content on a liquid crystal panel; setting a refresh rate of an i-th row in the displayed content to a first refresh rate if the grayscale values of all the pixels in the i-th row are below a predetermined value; and setting a refresh rate of a j-th row in the displayed content to a second refresh rate if at least one grayscale value of the pixels in the j-th row is not lower than a predetermined value, wherein i≠j and the first refresh rate is lower than the second. Thereby solving a technical problem in the related arts where terminal power consumption is reduced by merely decreasing the power drained by the backlight. This enables setting different refresh rates for brighter and darker rows in a displayed content, which can reduce the power consumption of the liquid crystal panel and display chip in a terminal and further reduce the power consumption of the terminal.