Dynamic Mask for Multi-Projector Overlap Brightness Control

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Solution Overview

Problem

Current image projection systems using multiple projectors often result in over-brightness in overlap zones, particularly problematic for dark images in applications like flight simulators, due to the accumulation of light fluxes and the phenomenon of 'multiple blacks', which existing solutions fail to adequately address.

Innovation Solution

Implementing a dynamic mask in the form of a transparent screen that can be scalable, controlled, and slaved, displaying intermediate images to adjust the brightness and minimize visual defects in overlap zones, allowing for real-time adaptation to projection parameters and eliminating the need for precise mask positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If electronic cross-fading is used to adjust brightness in overlap zones, then bright images are improved, but dark images suffer from multiple blacks phenomenon

Engineering Contradiction:
Improvebrightness in overlap zonesVSAvoidimage quality for dark scenes
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

A transparent screen is introduced as an intermediary device between the projectors and the projection surface. This screen displays mask images that selectively attenuate light in overlap zones, serving as a mediator that enables independent control of brightness without directly modifying the projector output. The transparent screen acts as a flexible intermediary that can be precisely positioned and controlled to resolve the contradiction between bright and dark image quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the optical parameters of the transparent screen by displaying different mask images with varying transparency levels. By adjusting the mask image parameters (transparency, darkness, pattern), the system can adapt to different projection scenarios - using lighter masks for bright images and darker masks for dark images, thereby resolving the multiple blacks phenomenon while maintaining brightness control.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If mechanical or optical masks are used to prevent multiple blacks, then dark image quality is improved, but system complexity and configuration difficulty increase

Engineering Contradiction:
Improveimage quality for dark scenesVSAvoidmask configuration and positioning
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces complex mechanical mask systems with an electronic display system. Instead of using physical masks that require precise mechanical positioning and adjustment, the system uses a transparent screen with electronically controlled mask images. This substitution eliminates the need for complex mechanical configurations while achieving the same light attenuation effect, thereby reducing device complexity while maintaining dark image quality.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mask system is made dynamic and adaptable through electronic control. The transparent screen can display different mask images in real-time based on the projection content and overlap zone characteristics. This dynamic capability allows the system to adapt to various scenarios without requiring physical reconfiguration, significantly reducing the complexity associated with static mechanical or optical masks.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If fixed masks are used for projection, then positioning is simplified, but adaptability to different projection parameters is reduced

Engineering Contradiction:
Improvemask positioningVSAvoidadaptation to projection parameters
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The invention transforms the static mask into a dynamic electronic display on a transparent screen. The mask image can be programmatically adjusted to match different projection parameters such as zoom levels, focus settings, and projector positions. This dynamic nature maintains ease of operation through software control while providing full adaptability to varying projection conditions, eliminating the trade-off between fixed positioning and parameter adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The transparent screen with programmable mask images serves multiple functions: it can adapt to different projector configurations, accommodate various projection surfaces, and work with different image brightness levels. This universal design allows a single system to handle diverse projection scenarios without requiring multiple fixed masks, thereby maintaining operational simplicity while maximizing versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 dynamic mask effectively minimizes over-brightness and 'multiple blacks' in overlap zones, providing flexible and adaptive solutions for various projection scenarios without the need for precise mask placement, enhancing image quality across different brightness levels and applications.

Implementation Method 1

electronic means, consisting in modifying the video level of the images in the overlap zones

Methodology Applied
Scientific EffectElectro-optical modulation: Electro-Optic Effects

Implementation Method 2

The areas of overlap of several images therefore remain over-bright (the light fluxes being added)

Methodology Applied
Scientific EffectLight transmission and absorption: Absorption (EM radiation)

Data Source

PatentEP2887657B1Electro-optical crossfading
Publication Date: 2019.05.22 THALES SA
  • EP2887657B1 patent drawingFigure 1
  • EP2887657B1 patent drawingFigure 2A
  • EP2887657B1 patent drawingFigure 2B~2E

AI summary

An electro-optical device for crossfading, comprising a plurality of video projectors projecting light beams onto a common passive screen, with at least one overlap zone between the light beams; at least one dynamic mask interposed between at least one of the video projectors and the common passive screen, the dynamic mask being constituted by the display of a mask image on a transparent screen and modifying the display of the overlap zone. Developments describe, in particular, the use of a plurality of mask images, the use of a flexible transparent screen, the determination of one or more mask images by computational means, the use of image acquisition means capturing at least a portion of the overlap zone of the light beams to minimize the optical effect of multiple blacks and/or over-brightness in the overlap zone, and the use of a plurality of dynamic masks.