Image Forming Apparatus Color Correction Using Foundation Detection

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Solution Overview

Problem

Existing image forming apparatuses struggle to accurately correct image forming conditions when using recording media with colors distant from the origin of the color spatial coordinate system, leading to erroneous color change calculations.

Innovation Solution

An image forming apparatus that includes a detector to measure the color of the formed image and the underlying foundation, along with a processing circuitry that uses reference data to correct the image forming conditions based on the detected colors and their positions in the color space, allowing for appropriate adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If color correction is performed based on the origin of a color spatial coordinate system (Lab color space), then color correction can be established for standard recording media, but color change amounts are erroneously calculated when using recording media with colors distant from the origin (such as colored paper)

Engineering Contradiction:

Improvecolor change calculation accuracyVSAvoidadaptability to different recording medium colors

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by making the correction reference point adaptive rather than fixed. Instead of always using the origin (0,0,0) of the Lab color space as the reference, the system dynamically determines a reference point based on the actual foundation color detected from the recording medium. This allows the correction algorithm to be locally adapted to each specific recording medium, ensuring accurate color change calculations whether the medium is white, colored, or has varying background characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by modifying the reference point parameter in the color correction calculation. The reference point is changed from a fixed origin (0,0,0) to a dynamic value determined by detecting the foundation color and calculating an appropriate reference point in the Lab color space. This parameter adaptation enables the system to handle diverse recording media while maintaining measurement precision.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If the correction reference point is fixed at the origin of the color space, then the calculation method is simple and established, but it fails to account for the actual foundation color of the recording medium

Engineering Contradiction:

Improvesimplicity of correction methodVSAvoidcolor correction accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing foundation color detection and reference point determination before executing the color correction calculation. The system first detects the foundation color from the recording medium, calculates an appropriate reference point in the Lab color space based on this detection, and then uses this pre-determined reference point for the subsequent color correction process. This preliminary preparation ensures both accuracy and systematic handling of the correction task.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary element - the dynamically determined reference point in the Lab color space - that mediates between the fixed coordinate system and the variable foundation colors. This intermediary reference point serves as an adaptive origin that accounts for the actual foundation color while enabling the correction calculation to proceed systematically. It bridges the gap between the simplicity of fixed-reference methods and the accuracy of adaptive methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 precise correction of image forming conditions, considering the relationship between the image color and the foundation color, thereby improving the accuracy of color adjustments and maintaining desired color densities.

Implementation Method 1

a color density of a patch image or the like as a test chart formed on a recording medium is detected by a sensor

Methodology Applied

Scientific EffectColorimetry: Absorption Spectroscopy

Data Source

PatentUS11825061B2Image forming apparatus, method of controlling, and computer program product correcting an image forming condition based on color of formed image and medium under image, and color space reference data

Publication Date: 2023.11.21 KONICA MINOLTA INC

AI summary

An image forming apparatus includes: an image forming mechanism that forms a first image on a recording medium based on an image forming condition; a detector that detects a first color of the first image and a color of a foundation under the first image from the recording medium on which the first image is formed; a storage that stores reference data for specifying a relative relationship between a position of the first color in a color space and a position of the color of the foundation in the color space; and a processing circuitry, wherein the processing circuitry corrects the image forming condition based on the reference data and the first color and the color of the foundation detected by the detector.