Display Sub-Pixel Architecture for Wide Luminance Range

Solution Overview

Problem

Current emissive displays, such as HUDs, HWDs, and HMDs, face challenges in achieving extremely low luminance levels for operation in low light conditions while maintaining the ability to reach high brightness levels for use in bright environments, which is essential for visibility under varying ambient conditions without impairing real-world perception.

Innovation Solution

The system employs a sub-pixel architecture with two sets of sub-pixels, where the second set has a maximum brightness that is dimmer than the first set, allowing for reduced luminous efficacy through methods like smaller emitter areas, mask layers, or filters, enabling a wider dynamic range and improved modulation transfer function, especially in night mode, while reducing bandwidth and transistor complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If emissive displays are driven to extremely low luminance levels for low light conditions, then visibility in dark environments is improved, but the capability to reach high brightness levels for bright environments is compromised

Engineering Contradiction:

Improveluminance levelVSAvoidbrightness range adaptability

Core Design Contradiction:

Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The pixel is divided into two separate sub-pixels: a first sub-pixel optimized for high brightness output and a second sub-pixel optimized for low luminance output. This segmentation allows each sub-pixel to be independently driven, enabling the display to achieve both extremely low luminance levels and high brightness levels by selectively activating the appropriate sub-pixel based on ambient lighting conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each sub-pixel is designed with different local characteristics: the first sub-pixel has higher luminous efficacy for bright environment performance, while the second sub-pixel has lower luminous efficacy optimized for night mode. This local quality differentiation enables the display to maintain optimal performance across the full range of ambient lighting conditions without compromise.

Inventive Principle:

Principle #3Local quality

2Device complexity

If a single set of sub-pixels is used for both day and night modes, then device complexity is reduced, but image performance and modulation transfer function deteriorate in night mode

Engineering Contradiction:

Improvesub-pixel architecture complexityVSAvoidimage performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The pixel is divided into two separate sub-pixels: a first sub-pixel optimized for high brightness output and a second sub-pixel optimized for low luminance output. This segmentation allows each sub-pixel to be independently driven, enabling the display to achieve both extremely low luminance levels and high brightness levels by selectively activating the appropriate sub-pixel based on ambient lighting conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each sub-pixel is designed with different local characteristics: the first sub-pixel has higher luminous efficacy for bright environment performance, while the second sub-pixel has lower luminous efficacy optimized for night mode. This local quality differentiation enables the display to maintain optimal performance across the full range of ambient lighting conditions without compromise.

Inventive Principle:

Principle #3Local quality

3Illumination intensity

If luminous efficacy is reduced to achieve lower luminance levels, then low light visibility is improved, but bandwidth requirements and transistor complexity increase

Engineering Contradiction:

Improveluminance levelVSAvoidbandwidth and transistor complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The pixel is divided into two separate sub-pixels: a first sub-pixel optimized for high brightness output and a second sub-pixel optimized for low luminance output. This segmentation allows each sub-pixel to be independently driven, enabling the display to achieve both extremely low luminance levels and high brightness levels by selectively activating the appropriate sub-pixel based on ambient lighting conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The display dynamically selects which sub-pixel to activate based on ambient lighting conditions. In bright environments, the first sub-pixel is driven; in low light environments, the second sub-pixel is driven. This dynamic adaptation optimizes performance for each condition while managing bandwidth and complexity requirements efficiently.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3901689B1Display element, system, and method

Publication Date: 2023.05.31 ROCKWELL COLLINS INC

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AI summary

A system may include a display element (116). The display element may include pixel groups. Each of the pixel groups may include a first set of sub-pixels and a second set of sub-pixels. The first set of sub-pixels may include: a first sub-pixel (802); a second sub-pixel (804); and a third sub-pixel (806). The second set of sub-pixels may include: a fourth sub-pixel (808); a fifth sub-pixel (810); and a sixth sub-pixel (812). Each of the fourth sub-pixel, the fifth sub-pixel, and the sixth sub-pixel may have a maximum brightness that is dimmer than a maximum brightness of each of the first sub-pixel, the second sub-pixel, and the third sub-pixel. Some or all sub-pixels of one of the first set of sub-pixels or the second set of sub-pixels may be driven while all sub-pixels of the other of the first set of sub-pixels or the second set of sub-pixels are undriven.