Color Chart Segmentation Reduces Flare Influence

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Solution Overview

Problem

Existing color charts for image forming apparatuses often result in a large difference in gradation or luminance between color patches and the background, which hampers sufficient reduction of flare influence and degrades image quality.

Innovation Solution

A color chart with a first portion having no patches and a second portion containing a plurality of patches with varying densities or luminances, where a reference patch indicates a color with a reference density or luminance, and the patches are arranged in order of increasing or decreasing density/luminance from the reference patch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If color patches are arranged with constant rate of color reproduction density change, then color reproduction adjustment is enabled, but the difference in gradation between patches and background becomes large

Engineering Contradiction:

Improvecolor reproduction density measurementVSAvoidflare influence

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The color chart is divided into multiple regions (first through fourth portions) with different patch density characteristics. The first portion has high patch density adjacent to the background, the second portion has medium density, the third portion has low density, and the fourth portion has very low density. This local variation in patch density allows different regions to serve different measurement purposes while collectively reducing the overall difference in gradation between patches and background, thereby minimizing flare influence.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The color chart is segmented into four distinct portions, each containing color patches with different density characteristics. This segmentation allows the system to distribute patches across different density ranges, preventing any single large difference in gradation between patches and background, thus reducing flare influence while maintaining comprehensive color reproduction measurement capability.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If color patches are arranged with constant rate of color reproduction density change, then color reproduction adjustment is enabled, but image quality deteriorates

Engineering Contradiction:

Improvecolor reproduction density measurementVSAvoidimage quality

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

Different portions of the color chart have different patch density characteristics optimized for specific measurement ranges. The first portion through fourth portion each provide locally optimized patch arrangements that maintain high image quality while enabling comprehensive color reproduction measurement across the full density range.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The color chart is divided into four segments with progressively different patch densities. This segmentation allows each segment to maintain optimal image quality for its specific density range while collectively covering the entire color reproduction spectrum, thereby resolving the contradiction between measurement precision and image quality.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If multiple color patches with different densities are used, then comprehensive color measurement is achieved, but the difference in luminance between patches and background increases

Engineering Contradiction:

Improvecolor measurement rangeVSAvoidflare influence

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The color chart uses four distinct portions with different patch density characteristics. This local quality differentiation allows comprehensive color measurement across all density ranges while each portion contributes to minimizing the overall luminance difference between patches and background, thereby reducing flare influence.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The color chart is segmented into four portions that collectively provide comprehensive color measurement capability. By distributing patches across different density ranges in separate portions, the system achieves versatile color measurement while preventing any single large luminance difference that would cause flare, thus resolving the contradiction between adaptability and flare reduction.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP3982621B1Color chart, image forming apparatus, and reading device

Publication Date: 2025.01.22 RICOH CO LTD

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AI summary

A color chart (1000) includes a first portion (101) and a second portion (102). The first portion (101) includes no patch. The second portion (102) includes a plurality of patches having different densities or luminances. The plurality of patches includes a reference patch (201) indicating a color having a reference density or luminance. The reference patch (201) is adjacent to the first portion. The plurality of patches is located in order of increasing density from the density of the color indicated by the reference patch (201), decreasing density from the density of the color indicated by the reference patch (201), increasing luminance from the luminance of the color indicated by the reference patch (201), or decreasing luminance from the luminance of the color indicated by the reference patch (201).