Display Device Luminance Control for Afterimage Reduction

Solution Overview

Problem

Display devices often exhibit afterimages due to luminance discrepancies between the letterbox area and the image display area, particularly when screen ratios do not match, leading to visual recognition of the reduced luminance area as a bar.

Innovation Solution

A display device with a luminance control unit that analyzes images to dynamically adjust the luminance of a boundary luminance variable area adjacent to the letterbox, reducing luminance more for dynamic or complex images and less for static or simple images, thereby minimizing visual recognition of the luminance reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If luminance is reduced in the boundary area adjacent to the letterbox, then afterimage deviation is reduced, but visual recognition of the luminance reduced area as a bar increases

Engineering Contradiction:

Improveafterimage reductionVSAvoidvisual recognition of luminance reduced area

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by differentiating luminance control in three distinct zones: the letterbox area, the boundary luminance variable area adjacent to the letterbox, and the remaining image display area. By applying different luminance reduction strategies to different local regions, the patent reduces afterimage in the boundary area while minimizing the visual impact of luminance reduction through gradual transition.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by dynamically adjusting the luminance of the boundary area based on image characteristics. The luminance control unit analyzes whether the current image is static or dynamic and adjusts the luminance reduction level accordingly, allowing the system to adapt to different display scenarios and optimize both afterimage reduction and visual comfort.

Inventive Principle:

Principle #15Dynamics

2Reliability

If luminance is reduced in the boundary area adjacent to the letterbox, then afterimage deviation is reduced, but display quality in the boundary area deteriorates

Engineering Contradiction:

Improveafterimage reductionVSAvoiddisplay quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by differentiating luminance control in three distinct zones: the letterbox area, the boundary luminance variable area adjacent to the letterbox, and the remaining image display area. By applying different luminance reduction strategies to different local regions, the patent reduces afterimage in the boundary area while minimizing the visual impact of luminance reduction through gradual transition.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial action by selectively reducing luminance only in the boundary luminance variable area adjacent to the letterbox, rather than reducing luminance across the entire image display area. This partial application of luminance reduction minimizes the impact on overall display quality while still achieving afterimage reduction in the critical boundary region.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If luminance control is applied to the entire image display area, then afterimage is reduced, but visual recognition of the luminance reduced area increases

Engineering Contradiction:

Improveafterimage reductionVSAvoidvisual recognition of luminance reduced area

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by differentiating luminance control in three distinct zones: the letterbox area, the boundary luminance variable area adjacent to the letterbox, and the remaining image display area. By applying different luminance reduction strategies to different local regions, the patent reduces afterimage in the boundary area while minimizing the visual impact of luminance reduction through gradual transition.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies segmentation by dividing the image display area into multiple zones with different luminance control characteristics. The boundary luminance variable area is segmented as a distinct region between the letterbox and the main image display area, allowing independent luminance adjustment that addresses afterimage while maintaining visual comfort.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11783770B2Display device

Publication Date: 2023.10.10 LG DISPLAY CO LTD

AI summary

A display device includes a display panel which includes a letterbox area and an image display area which displays an image and includes a boundary luminance variable area extending from the letterbox area; and a luminance control unit which controls a reduced luminance amount of the boundary luminance variable area based on the image.