Display Substrate Pixel Circuit Layout for FDC Brightness Uniformity

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Solution Overview

Problem

Existing display technologies face challenges in maximizing the screen-to-body ratio without compromising light transmittance and brightness uniformity in regions accommodating cameras, as conventional methods either limit the size of the full display with camera (FDC) region or affect light transmittance due to conductive connection lines.

Innovation Solution

A display substrate design combining pixel circuit built-out and built-in methods, with alternating arrangements of light emitting units and pixel circuits, optimizing light transmittance and size of the FDC region while ensuring brightness uniformity through interval arrangements and balanced light emitting element ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If pixel circuits are built-in under light emitting elements, then the screen-to-body ratio is improved, but light transmittance deteriorates due to conductive connection lines blocking light

Engineering Contradiction:
Improvescreen-to-body ratioVSAvoidlight transmittance
Core Design Contradiction:
Area of stationary objectVSIllumination intensity

Solution Approach 1:

The display region is divided into a first display region with built-in pixel circuits and a second display region with built-out pixel circuits. This segmentation allows different areas to have different configurations, optimizing both light transmittance and screen-to-body ratio in respective regions while avoiding the blocking effect of conductive connection lines in the first display region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different display regions are assigned different pixel circuit configurations based on local requirements. The first display region uses built-in pixel circuits for high light transmittance, while the second display region uses built-out pixel circuits for easier wiring and manufacturing, allowing each region to have optimal local characteristics.

Inventive Principle:
Principle #3Local quality

2Area of stationary object

If the FDC region size is increased, then the screen-to-body ratio is improved, but brightness uniformity deteriorates due to light blocking by pixel circuits and connection lines

Engineering Contradiction:
ImproveFDC region sizeVSAvoidbrightness uniformity
Core Design Contradiction:
Area of stationary objectVSIllumination intensity

Solution Approach 1:

The display region is segmented into first and second display regions with different pixel circuit configurations. The first display region with built-in pixel circuits provides high light transmittance and uniform brightness, while the second display region accommodates the remaining pixel circuits, allowing the FDC region to be expanded without compromising brightness uniformity in the critical first display region.

Inventive Principle:
Principle #1Segmentation

3Illumination intensity

If all pixel circuits are built-out to the peripheral region, then light transmittance is improved, but device complexity increases due to extended connection lines

Engineering Contradiction:
Improvelight transmittanceVSAvoidconnection line complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

Pixel circuits are segmented into those built-in the first display region and those built-out to the second display region. This segmentation reduces the complexity of connection lines compared to building out all pixel circuits, as some circuits remain localized under their corresponding light emitting elements, shortening connection paths and reducing overall wiring complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pixel circuits for the first display region are merged with the light emitting elements by placing them directly underneath, eliminating the need for separate connection lines for these circuits. This merging simplifies the overall device structure by reducing the number of connection lines required compared to a complete built-out configuration.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4651689A1Display substrate and display device
Publication Date: 2025.11.19 BOE TECHNOLOGY GROUP CO LTD
  • EP4651689A1 patent drawingFigure 1~2
  • EP4651689A1 patent drawingFigure 3~4A
  • EP4651689A1 patent drawingFigure 4B

AI summary

A display substrate, comprising: a base, a plurality of first light-emitting units and a plurality of second light-emitting units which are located in a first display region, a plurality of first pixel circuits located in the first display region, and a plurality of second pixel circuits located in a second display region. Each first light-emitting unit comprises at least one first light-emitting element. Each second light-emitting unit comprises at least one second light-emitting element. The at least one first light-emitting unit is adjacent to the at least one second light-emitting unit. At least one first pixel circuit is electrically connected to the at least one first light-emitting element and is configured to drive the at least one first light-emitting element to emit light. At least one second pixel circuit is electrically connected to the at least one second light-emitting element and is configured to drive the at least one second light-emitting element to emit light.