Rolling Dimming Zones for LED Display Uniformity

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Solution Overview

Problem

LED-based displays with fixed dimming zones experience uneven decay rates, leading to visible edges and non-uniform brightness over time due to differential usage of LEDs in different zones, causing image quality issues.

Innovation Solution

Implementing rolling dimming zones, where the grouping and positioning of LEDs are periodically changed across the display to maintain uniform decay rates and blur the boundaries between zones, using a controller to manage the LEDs and adjust brightness levels based on content and usage patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If fixed dimming zones are used in LED displays, then local brightness control is achieved, but visible edges and non-uniform brightness occur due to differential LED decay rates

Engineering Contradiction:
Improvelocal brightness controlVSAvoiduniformity of brightness
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies the dynamics principle by making the dimming zones movable rather than fixed. The zones are shifted periodically across the display panel, causing different LEDs to be assigned to different zones over time. This dynamic redistribution equalizes the usage and decay rates of all LEDs, preventing the formation of visible edges and maintaining uniform brightness across the display.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If LEDs are grouped into fixed zones, then dimming control is achieved, but visible boundaries form between zones over time

Engineering Contradiction:
Improvedimming controlVSAvoidvisibility of zone boundaries
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent implements periodic action by regularly shifting the positions of dimming zones across the display. This periodic redistribution ensures that no single group of LEDs remains in the same zone indefinitely, preventing the formation of stable visible boundaries while maintaining effective dimming control through the controller.

Inventive Principle:
Principle #19Periodic action

3Device complexity

If dimming zones remain stationary, then control simplicity is maintained, but LED decay rates become non-uniform across zones

Engineering Contradiction:
Improvecontrol simplicityVSAvoiduniformity of decay rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent resolves this contradiction by introducing dynamic zone shifting controlled by a controller. While the control logic becomes slightly more complex, the overall system maintains simplicity through automated periodic shifts. This dynamic approach ensures uniform LED decay rates across all zones by redistributing which LEDs are active in which zones over time, preventing localized overuse and differential aging.

Inventive Principle:
Principle #15Dynamics

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 reduces the visibility of dimming zone boundaries and maintains consistent image quality by leveling the decay rate of LEDs, thereby enhancing the overall display performance and longevity.

Implementation Method 1

The LEDs 104 may provide light to display an image on the display 100

Methodology Applied
Scientific EffectLight emitting diode: Light Emitting Diode

Data Source

PatentEP3750150B1Displays with dimming zones that change
Publication Date: 2023.08.16 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3750150B1 patent drawingFigure 1
  • EP3750150B1 patent drawingFigure 2
  • EP3750150B1 patent drawingFigure 3

AI summary

In example implementations, a display is provided. The display includes a plurality of light emitting diodes (LEDs), a thin film transistor (TFT) substrate, a liquid crystal layer, a color filter (CF) substrate, and a controller. The TFT substrate is formed over the LEDs to control emission of light from the plurality of LEDs. The liquid crystal layer is formed over the TFT substrate. The CF substrate is formed over the liquid crystal layer to control a color of the light emitted from the plurality of LEDs. The controller is communicatively coupled to the plurality of LEDs to group subsets of LEDs of the plurality of LEDs into a plurality of local dimming zones, wherein the subsets of LEDs in each one of the plurality of local dimming zones changes over time.