Backlight Power Management for HDR Displays

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High power consumption in backlights of high-brightness and High Dynamic Range (HDR) displays leads to increased operating costs and reduced product lifetime/maintenance, posing a challenge for efficient energy usage.

Innovation Solution

Implementing spatially-modulated lighting elements, such as LEDs, in displays that adjust power consumption based on image content through a power management system, which includes a Down-Sampler, Power Matrix Calculation Module, and Power State Machine to dynamically adjust backlight modulation levels and LCD pixel data, optimizing power allocation and reducing overall energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If high brightness backlight is used to achieve HDR display, then image quality is improved, but power consumption increases

Engineering Contradiction:
Improvebacklight brightnessVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The backlight is divided into multiple independently controllable zones or regions, allowing different brightness levels to be applied to different areas of the display based on the local image content requirements, thereby achieving HDR效果 while reducing overall power consumption

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The backlight brightness is dynamically adjusted in real-time based on the analyzed image content, using temporal modulation to provide high brightness only when and where needed, rather than maintaining constant high brightness across the entire display

Inventive Principle:
Principle #15Dynamics

Solution Approach 3:

The system changes the brightness parameter of the backlight dynamically based on image analysis, adjusting between high and low states to match the content requirements, thereby achieving energy efficiency while maintaining image quality

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high power is supplied to maintain product lifetime, then reliability is improved, but operating costs increase

Engineering Contradiction:
Improveproduct lifetimeVSAvoidoperating costs
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The backlight operates in periodic cycles of high and low brightness states, using pulse-width modulation or frame-by-frame adjustment to provide necessary brightness only during required periods, extending component life while reducing continuous power consumption and operating costs

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces power consumption while maintaining image quality by dynamically adjusting backlight power based on image content, preventing color shifts and motion artifacts, thereby extending the product's lifespan and lowering operational costs.

Implementation Method 1

spatially-modulated lighting elements (e.g., LEDs)

Methodology Applied
Scientific EffectLight emitting diode: Light Emitting Diode

Implementation Method 2

light sources are divided into sections

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3564939B1Improved power management for modulated backlights
Publication Date: 2022.11.09 DOLBY LABORATORIES LICENSING CORP
  • EP3564939B1 patent drawingFigure 1
  • EP3564939B1 patent drawingFigure 2A~2B
  • EP3564939B1 patent drawingFigure 3A~3B

AI summary

The invention concerns a method implemented in a processing device of a display including a backlight and a front modulator, the method comprising: evaluating image data representative of an image to be displayed to determine power information associated with portions of the backlight associated with at least one of a plurality of regions of the image to be displayed, comparing the power information to a threshold power value to determine whether the power information indicates an exceedance of the threshold power value, and when the power information indicates an exceedance of the threshold power value, reallocating power within the backlight to implement a change in brightness of an area of the image to be displayed associated with a particular region and to change modulation by the front modulator to accommodate the reallocation of power by the backlight. The disclosure further comprises a processing device, a display and a computer-readable medium.