Digital Black Level Blending for Projector Overlap Regions

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Projectors projecting 'black' images still emit some light, causing overlap regions to appear brighter than surrounding areas when multiple projectors are used, distracting from the content, especially in dark scenes, and existing solutions like neutral density filters are inefficient for high-lumen projectors and difficult to implement.

Innovation Solution

A digital black level blending system that adjusts the brightness of non-overlap regions to minimize the visibility of overlap areas by determining correspondences between projected points and image modulators, and controlling pixel brightness to match the overlap regions, using electrical and digital methods adaptable to changes in projector and screen configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If neutral density filter assemblies are moved in and out of the light path to create non-distracting optical blend for dark scenes, then the overlap regions become less noticeable, but the filters overheat and distort when used with projectors much higher than 8000 lumens

Engineering Contradiction:
Improvevisibility of overlap regionsVSAvoidfilter temperature
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent replaces the mechanical/optical solution (moving neutral density filter assemblies) with a digital processing solution. The system captures images from multiple projectors, identifies overlap regions, and digitally adjusts the brightness of pixels in these regions to match adjacent non-overlap regions, eliminating the need for physical filters and their associated thermal problems.

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

Solution Approach 2:

The patent creates a digital copy of the projected images and processes this copy to correct the overlap region brightness. By working with digital image data rather than manipulating the actual light path with physical filters, the system can adjust brightness levels without introducing heat-related distortion or requiring complex mechanical filter assemblies.

Inventive Principle:
Principle #26Copying

2Reliability

If neutral density filter assemblies are made with heat-tolerant materials, then they can withstand higher lumen projectors, but these materials are harder to work with, expensive and/or have inferior optical properties

Engineering Contradiction:
Improvefilter heat toleranceVSAvoidfilter manufacturing difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent eliminates the need for physical filter assemblies entirely by substituting the optical filtering approach with digital image processing. This removes all manufacturing challenges associated with heat-tolerant materials, including their difficulty to work with, high cost, and inferior optical properties.

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

3Temperature

If fixed geometry neutral density filter assemblies are positioned far away from the lens, then they can be used with higher lumen projectors, but the arrangement becomes awkward

Engineering Contradiction:
Improvefilter heat toleranceVSAvoidfilter arrangement ease
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

The patent replaces the complex mechanical arrangement of filter assemblies positioned far from the lens with a digital processing system. This eliminates the awkward physical arrangement requirements while still achieving the goal of blending overlap regions in high-lumen projector applications.

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

4Adaptability or versatility

If digital black level blending is used instead of optical/physical solutions, then the system can adapt to changes in projector/screen configuration and alignment, but requires electrical/digital processing

Engineering Contradiction:
Improveadaptation to configuration changesVSAvoiddigital processing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic digital processing system that continuously adapts to changes in projector and screen configuration. The system captures real-time images, identifies overlap regions, and adjusts pixel brightness levels dynamically, allowing it to respond to alignment changes and configuration variations without requiring physical reconfiguration of optical components.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3331241B1System and method for digital black level blending
Publication Date: 2020.10.07 CHRISTIE DIGITAL SYSTEMS USA INC
  • EP3331241B1 patent drawingFigure 1
  • EP3331241B1 patent drawingFigure 2
  • EP3331241B1 patent drawingFigure 3

AI summary

A system and method for digital black level blending is provided. The system comprises: projectors located to project respective projector images overlapping in overlap regions; at least one sensor configured to acquire digital images of at least portions of the plurality of projector images; and a computing device configured to, for each given projector: determine, using the at least one sensor, respective correspondences between projected points of a given projector image and respective points of respective image modulators of other projectors of the projectors, the correspondences representing the respective points of the respective image modulators of the other projectors that correspond to overlap regions; determine respective brightness of the overlap regions; and, control pixels of an image modulator of the projector, and each of the respective image modulators, at least adjacent edge pixels corresponding to overlap region edges, to increase brightness in corresponding projector image regions using the respective brightness.