OLED Pixel Aperture and Capacitance Layout for Stepped Boundary Hiding

Solution Overview

Problem

Conventional flat panel display devices have a rectangular shape, making them unsuitable for applications requiring specific shapes, and deformed display devices with circular, oval, or trapezoidal shapes suffer from visible stepped shapes at the boundary between the display area and the bezel area.

Innovation Solution

A display device with a substrate having an active area of a non-rectangular shape and a bezel area, featuring first and second subpixels with different capacitance values for storage capacitors, allowing for uniform luminance across the display and eliminating the visibility of stepped shapes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If deformed display devices with non-rectangular shapes are developed to satisfy consumer demand for various shapes, then adaptability to different applications is improved, but an abnormal stepped shape becomes visible in the boundary area between display area and bezel area

Engineering Contradiction:

Improveadaptability to different shapesVSAvoidstepped shape visibility

Core Design Contradiction:

Adaptability or versatilityVSShape

Solution Approach 1:

The patent applies local quality by differentiating the treatment of subpixels based on their location. First subpixels in the active area have a first aperture ratio, while second subpixels in the boundary area have a second aperture ratio that is smaller than the first. This local differentiation allows the display to adapt to non-rectangular shapes while eliminating the visible stepped shape at boundaries.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the aperture ratio parameter for subpixels located in the boundary area between the active area and bezel area. By setting the aperture ratio of second subpixels to be smaller than that of first subpixels, the display creates a gradual transition that eliminates the abnormal stepped shape while maintaining adaptability to various display shapes.

Inventive Principle:

Principle #35Parameter changes

2Shape

If the aperture ratio of subpixels is uniformly reduced to eliminate stepped shape visibility, then shape uniformity is improved, but luminance output decreases

Engineering Contradiction:

Improveshape uniformityVSAvoidluminance output

Core Design Contradiction:

ShapeVSIllumination intensity

Solution Approach 1:

The patent applies local quality by differentiating the treatment of subpixels based on their location. First subpixels in the active area have a first aperture ratio, while second subpixels in the boundary area have a second aperture ratio that is smaller than the first. This local differentiation allows the display to adapt to non-rectangular shapes while eliminating the visible stepped shape at boundaries.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the aperture ratio parameter for subpixels located in the boundary area between the active area and bezel area. By setting the aperture ratio of second subpixels to be smaller than that of first subpixels, the display creates a gradual transition that eliminates the abnormal stepped shape while maintaining adaptability to various display shapes.

Inventive Principle:

Principle #35Parameter changes

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

The display device achieves uniform luminance across non-rectangular active areas and bezel areas, effectively eliminating the visibility of stepped shapes, thus enhancing the aesthetic and functional appeal of deformed display devices.

Implementation Method 1

capacitance values of storage capacitors in subpixels within the active area and those in subpixels adjacent to the boundary area are set to be different

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS12317686B2OLED pixel with aperture proportional to capacitance

Publication Date: 2025.05.27 LG DISPLAY CO LTD

AI summary

A display device includes a substrate having an active area and a non-active area; a plurality of first subpixels arranged in the active area; and a plurality of second subpixels arranged adjacent to a boundary area between the active area and the non-active area, wherein the first and second subpixels have storage capacitors that have different capacitance values from each other, so that visibility of the stepped shape generated in the boundary area can be eliminated.