Color Chart Rearrangement for Diffuse Reflection Control

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Solution Overview

Problem

Conventional color calibration methods in image forming apparatuses face challenges due to diffuse reflection from neighboring color patches, leading to inaccurate color measurements and increased costs from additional structural components to mitigate this issue.

Innovation Solution

A chart creation method that rearranges color patches to restrict the spread of average color values within a predetermined range by exchanging measured color values between patches, using a control apparatus to create and print charts with rearranged patches, thereby minimizing the influence of diffuse reflection without increasing the number of chart sheets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a mechanism is added to block off light rays reflected on surroundings of the target color patch via diffuse reflection, then color measurement accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecolor measurement accuracyVSAvoidstructural components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the harmful diffuse reflected light rays from the measurement path by positioning the sensor to detect only directly reflected light from the target color patch, excluding light reflected from surrounding patches. This eliminates the need for additional blocking mechanisms while maintaining measurement accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a light shielding structure as an intermediary element between the target color patch and the sensor. This structure selectively blocks diffuse reflected light from surrounding patches while allowing directly reflected light from the target patch to reach the sensor, thus improving measurement accuracy without complex mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If black image regions are arranged between color regions to suppress diffuse reflection, then color measurement accuracy is improved, but the number of chart sheets increases and material consumption increases

Engineering Contradiction:
Improvecolor measurement accuracyVSAvoidconsumption materials
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating localized light shielding at each target color patch position rather than using extensive black regions between all color patches. The sensor is positioned to detect light only from the immediate target patch area, providing local measurement accuracy without requiring global chart structure modifications that would increase material consumption.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If black image regions are arranged between color regions to suppress diffuse reflection, then color measurement accuracy is improved, but measurement time increases

Engineering Contradiction:
Improvecolor measurement accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the measurement process by focusing the sensor on individual target color patches independently, measuring each patch separately without requiring comprehensive black region separators. This segmentation allows for faster measurement by eliminating the need to account for and compensate for diffuse reflection from surrounding patches, thus reducing overall measurement time while maintaining accuracy.

Inventive Principle:
Principle #1Segmentation

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 method enhances color measurement accuracy and reduces the need for additional structural components, preventing excessive material consumption and measurement time, while maintaining accurate color calibration.

Implementation Method 1

a scanner or an in-line sensor can receive a mixture of color information of light rays reflected on a color patch to be measured (target color patch) and color information of light rays reflected on neighboring color patches of the target color patch via diffuse (or irregular) reflection

Methodology Applied
Scientific EffectDiffuse reflection: Reflection

Data Source

PatentEP3065388B1Color chart creation method, control apparatus and non-transitory computer-readable storage medium storing chart creation control program
Publication Date: 2018.02.28 KONICA MINOLTA INC
  • EP3065388B1 patent drawingFigure 1~2
  • EP3065388B1 patent drawingFigure 3A~3B
  • EP3065388B1 patent drawingFigure 4A~4B

AI summary

A chart creation method to be used in a system including an image forming apparatus and a control apparatus, the control apparatus and a non-transitory computer-readable medium storing a chart creation control program are provided. The chart creation method includes: creating a print image of a chart; giving instructions to the image forming apparatus to print the chart and measure colors of the chart; obtaining measured color values of the color patches of the chart from the image forming apparatus; and rearranging the color patches of the chart so as to restrict spread of average color values of subgroups of color patches in the chart within a predetermined range. The chart creation method further includes: creating a print image of the color chart including the rearranged color patches, and giving instructions to the image forming apparatus to print the chart and measure colors of the chart.