Image Retention Measurement Using Gradient Pattern Analysis

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Solution Overview

Problem

Current methods for measuring image retention in display devices are either expensive, require controlled environments, or are prone to subjective errors, making it difficult to accurately quantify image retention, especially in field applications like medical diagnostics.

Innovation Solution

A method involving the display of test patterns with dark and light features, followed by analysis patterns with gradient features of varying levels, allowing for visual inspection and digital driving level correlation to quantify image retention, eliminating the need for expensive equipment and providing objective measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If luminance meters are used to measure image retention, then measurement capability is provided, but the equipment cost is high and controlled environment is required

Engineering Contradiction:
Improveimage retention measurementVSAvoidmeasurement equipment
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a camera to capture images of the display, creating a digital copy of the visual output. This digital copy is then processed to extract image retention measurements, replacing the need for expensive luminance meters and controlled environments with a standard camera and software analysis pipeline.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/optical measurement system (luminance meters) with a digital imaging system (camera). The measurement process transitions from direct optical measurement to digital image capture and computational analysis, simplifying the physical measurement apparatus while enabling flexible post-processing.

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

2Device complexity

If visual inspection method is used to measure image retention, then equipment cost is reduced, but subjective errors occur in judging when residual image disappears

Engineering Contradiction:
Improvemeasurement equipmentVSAvoidimage retention measurement
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements an automated feedback system where the camera captures images, software analyzes the captured images to detect residual image characteristics, and provides objective measurements. This closed-loop system eliminates subjective human judgment by using algorithmic analysis to determine when and how the residual image persists.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces software analysis as an intermediary between the visual display and the measurement process. The software acts as a mediator that processes the camera images, extracts quantitative data about image retention, and provides objective measurements, replacing direct human visual inspection with an automated computational intermediary.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If charge-coupled device detector and colorimeter are used, then objective image data is acquired, but the equipment is expensive and measurements require controlled environment

Engineering Contradiction:
Improveobjective image measurementVSAvoidon-site measurement capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent makes the measurement system universal by using a standard camera that can be deployed in various environments without requiring controlled conditions. The software analysis pipeline processes images from different lighting and environmental conditions, enabling the same system to function both in laboratories and in field deployments at customer sites.

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

Solution Approach 2:

The patent replaces expensive, fragile scientific instrumentation (charge-coupled device detectors and colorimeters) with a standard, inexpensive camera. This substitution uses a more robust, widely available device that can be easily deployed and replaced, sacrificing some measurement precision for greatly improved adaptability and reduced cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP2798847B1Method and system for determining image retention
Publication Date: 2018.08.22 BARCO NV
  • EP2798847B1 patent drawingFigure 1A~2D
  • EP2798847B1 patent drawingFigure 3A~4D
  • EP2798847B1 patent drawingFigure 5~6A

AI summary

A system and method for measuring and quantifying image retention in a display device. The method involves displaying a test pattern (206, 306, 406, 606, 706) having at least one dark feature (210, 310, 410, 610) and at least one light feature (208, 308, 408, 608). The method further involves the displaying an analysis pattern (202, 302, 402, 602) having at one gradient feature (204, 304, 404, 604a-c) with a plurality of regions of different levels. The levels of the gradient feature may then be matched up with the levels displayed in the regions formerly displaying the dark feature (210, 310, 410, 610) and/or the light feature (208, 308, 408, 608). Thus, image retention may be determined by visual inspection.