Flexible Display Panel Partial Driving for Uniform Luminance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Flexible display devices, such as foldable or rollable displays, experience non-uniform luminance when operating in a partial driving mode due to varying power supply voltage drops caused by changing numbers of emitting pixel rows during deformation.

Innovation Solution

The display device operates in a partial driving mode by setting a black region from a specific point of the display panel perpendicular to emission signal lines, ensuring a consistent number of emitting pixel rows and maintaining a constant power supply voltage, thereby achieving uniform luminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the flexible display panel operates in a partial driving mode with varying number of emitting pixel rows, then power consumption is reduced, but the power supply voltage varies causing non-uniform luminance

Engineering Contradiction:
Improvepower consumptionVSAvoidluminance uniformity
Core Design Contradiction:
Loss of energyVSIllumination intensity

Solution Approach 1:

The patent applies dynamics by making the emission cycle configuration variable based on the folding state. When the display is folded, the system dynamically adjusts to use only specific emission cycles (e.g., 1st and 3rd) for the visible region, while keeping the total number of emission cycles constant. This dynamic reconfiguration maintains stable power supply voltage and uniform luminance in the visible area while reducing overall power consumption by not activating pixels in the folded region.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the emission cycles into distinct groups (e.g., 1st, 2nd, 3rd, 4th emission cycles) and selectively activates only certain segments based on the display's folding state. In partial driving mode, only specific segments are used for the visible region, while other segments are deactivated for the folded region. This segmentation allows independent control of different display regions, maintaining luminance uniformity in the active region while reducing power consumption.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the flexible display panel is deformed to enable portability, then adaptability is improved, but the number of emitting pixel rows varies causing power supply voltage instability

Engineering Contradiction:
ImproveportabilityVSAvoidpower supply voltage
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system dynamically adapts its emission cycle configuration based on the folding state. When folded, it transitions from using all emission cycles across the full panel to using only specific emission cycles for the visible region. This dynamic adaptation maintains a constant number of active pixel rows in the visible area, ensuring stable power supply voltage while enabling portable folded configurations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent extracts or removes the emission cycles that correspond to the folded, non-visible region from the active display configuration. By taking out the unnecessary emission cycles for the hidden area, the system maintains a consistent number of emitting pixel rows in the visible region, thereby stabilizing the power supply voltage while enabling the flexible folded form factor.

Inventive Principle:
Principle #2Taking out (Extraction)

3Use of energy by moving object

If the display operates in partial driving mode to reduce power consumption, then energy efficiency is improved, but luminance uniformity deteriorates due to voltage variation

Engineering Contradiction:
Improveenergy efficiencyVSAvoidluminance uniformity
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The system dynamically reconfigures which emission cycles are active based on the visible region. In partial driving mode, it maintains a constant number of emission cycles for the visible area (e.g., using 1st and 3rd cycles for half the panel), which stabilizes the power supply voltage and ensures uniform luminance. Simultaneously, it reduces energy consumption by deactivating emission cycles corresponding to the folded, non-visible region.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by providing different emission cycle configurations to different regions of the display. The visible region maintains a consistent number of active emission cycles for uniform luminance, while the folded region has its emission cycles deactivated. This localized control achieves both energy efficiency and luminance uniformity in the active display area.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS12387643B2Display device, and method of operating a display device
Publication Date: 2025.08.12 SAMSUNG DISPLAY CO LTD
  • US12387643B2 patent drawing
  • US12387643B2 patent drawing
  • US12387643B2 patent drawing

AI summary

A display device includes a display panel including pixels, and a panel driver which drive the display panel. Each frame period for the display panel includes N emission cycles, where N is an integer greater than 1. In a partial driving mode, the panel driver sets a black region of the display panel from a M/N point of the display panel along a direction perpendicular to an emission signal line, where M is an integer greater than 0 and less than N, and drives the display panel to display an image corresponding to input image data in a remaining region of the display panel other than the black region and to display a black image in the black region.