Dynamic Flare Correction for Image Forming Device Colorimetry

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Solution Overview

Problem

Existing methods for correcting flare levels in colorimetric value acquisition for image forming devices are inefficient, as they either require pre-calculated flare correction data for various patch structures or involve lengthy measurement processes with colorimetric apparatuses, leading to increased waste and processing time.

Innovation Solution

The method involves measuring all patches of a chart with a scanner to acquire RGB values, correlating them with colorimetric values, and then using a part of the patches measured with a colorimetric apparatus to calculate and apply a correction amount to match the flare level, allowing for dynamic correction and reduced measurement time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If flare correction data is calculated in advance for a fixed chart, then the correction process is simplified, but the method cannot correspond to charts having various patch structures

Engineering Contradiction:
Improveease of flare correctionVSAvoidadaptability to various chart structures
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic flare correction by detecting the actual flare level of the measurement chart in real-time and adjusting the correction amount accordingly. Instead of using fixed pre-calculated correction data, the system dynamically adapts the flare correction based on the specific chart being measured, resolving the contradiction between simplification and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the flare correction parameter based on the detected flare level of the measurement chart. By making the correction amount a variable parameter rather than a fixed value, the system can adapt to different chart structures while maintaining a simplified correction process.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If all patches are measured with a colorimetric apparatus to acquire accurate colorimetric values, then measurement accuracy is improved, but processing time increases and waste paper is increased

Engineering Contradiction:
Improveaccuracy of colorimetric valueVSAvoidtime for acquiring colorimetric value
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the measurement process into two parts: patches that require colorimetric measurement and patches that can use scanner RGB values with flare correction. By dividing the patches into different measurement categories, the system reduces the number of time-consuming colorimetric measurements while maintaining overall accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of measuring all patches with the colorimetric apparatus, the system performs partial measurements only on necessary patches and uses corrected scanner values for others. This partial action approach achieves sufficient accuracy without the excessive time cost of measuring every patch.

Inventive Principle:
Principle #16Partial or excessive action

3Quantity of substance

If multiple charts are output to acquire colorimetric values, then comprehensive colorimetric data is obtained, but waste paper is increased

Engineering Contradiction:
Improveamount of colorimetric dataVSAvoidwaste paper
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The patent replaces the mechanical approach of outputting multiple physical charts for measurement with a computational approach using flare correction algorithms. By substituting physical multiplication of charts with digital signal processing, the system obtains comprehensive colorimetric data without increasing paper waste.

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

Solution Approach 2:

Instead of creating multiple physical charts, the system uses virtual copying and processing of chart data through flare correction calculations. The correction algorithm creates virtual measurements from a single或少量 charts, eliminating the need for multiple physical copies.

Inventive Principle:
Principle #26Copying

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

This approach enables efficient and accurate correction of flare levels across different charts, minimizing the need for extensive colorimetric measurements and reducing waste, while maintaining high color accuracy and processing speed.

Implementation Method 1

When an RGB value is acquired using the chart for creating a scanner profile or the chart for creating a printer profile, it is necessary to detect only reflected light from a patch to be measured.

Methodology Applied
Scientific EffectReflected light: Reflection

Implementation Method 2

measuring a chart for creating a scanner profile output from a printer with a scanner and a colorimetric apparatus and correlating an RGB value measured with the scanner with a colorimetric value such as an L*a*b* value of a CIE 1976 color space or an XYZ value of a CIE 1931 color space measured with the colorimetric apparatus

Methodology Applied
Scientific EffectColorimetry:

Implementation Method 3

When an RGB value is acquired, it is necessary to correct an influence by the flare... a method for calculating flare correction data in advance

Methodology Applied
Scientific EffectFlare correction:

Data Source

PatentEP3166300B1Colorimetric value acquisition method, image forming device, and colorimetric value acquisition control program
Publication Date: 2018.12.05 KONICA MINOLTA INC
  • EP3166300B1 patent drawingFigure 1~2
  • EP3166300B1 patent drawingFigure 3A~3B
  • EP3166300B1 patent drawingFigure 4A~4B

AI summary

A colorimetric value to correct a flare level of a chart is acquired simply and properly. An image forming device (30) measures all patches of a first chart in which the patches are rearranged in advance such that a flare level is uniform with an in-line scanner (35a) and an in-line colorimetric apparatus to acquire RGB values and L*a*b* values and creates a scanner profile. Thereafter, the image forming device (30) measures all patches of a second chart in which the patches are rearranged in advance such that a flare level is uniform with an in-line scanner (35a) to acquire RGB values, measures a part of the patches with the in-line colorimetric apparatus to acquire L*a*b* values, specifies an RGB value corresponding to the L*a*b* values using the scanner profile, calculates a difference between the specified RGB value and the acquired RGB value, calculates a corrected RGB value by applying the difference to the acquired RGB value, acquires an estimated L*a*b* value corresponding to the corrected RGB value using the scanner profile, and outputs the estimated L*a*b* value.