Color Shift Correction in Image Forming Apparatus

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Image forming apparatuses face insufficient color shift correction due to neglecting the position of colors other than the reference color, leading to misalignment in multi-color image formation.

Innovation Solution

An image forming apparatus comprising a printer, sensor, and processor that forms patterns with multiple colors, detects their positions, and corrects color shifts by aligning other colors with the reference color's position, using the distance between the farthest color pairs to adjust their positions in units of dots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If position correction is performed using only the reference color as baseline, then the correction process is simple, but the color shift correction is insufficient

Engineering Contradiction:

Improvecorrection process complexityVSAvoidcolor shift correction precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The correction process is divided into two distinct stages: first, correcting each color position relative to the reference color, and second, performing mutual correction between non-reference colors based on their distances from the reference color. This segmentation allows each stage to focus on specific correction objectives, improving overall precision without overwhelming complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention adds a new dimension to the correction process by considering not only the distance from the reference color but also the relative distances between non-reference colors themselves. This transforms the correction from a single-reference approach to a multi-dimensional spatial relationship approach, enabling more accurate color alignment.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Difficulty of detecting and measuring

If the position of only the reference color is used for correction, then the measurement process is simple, but the alignment accuracy of multi-color images deteriorates

Engineering Contradiction:

Improveposition measurement simplicityVSAvoidmulti-color image alignment accuracy

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The system performs feedback-based correction by measuring the actual positions of all color patterns, calculating their distances from the reference color, and using these measurements to adjust the printing positions. The feedback loop ensures that correction decisions are based on actual measured deviations rather than theoretical assumptions.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The invention changes the correction parameters from a single reference-point model to a multi-point spatial model. By calculating and utilizing the distances between multiple color patterns and the reference color, the system adapts the correction parameters to reflect the actual spatial relationships observed in the printed output.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If correction is performed without considering distances between non-reference colors, then the correction algorithm is simple, but the color alignment precision deteriorates

Engineering Contradiction:

Improvecorrection algorithm complexityVSAvoidcolor alignment precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The system performs preliminary measurement and calculation of distances between all color patterns and the reference color before executing the correction. This preliminary action provides the necessary spatial relationship data that guides the subsequent correction process, ensuring that adjustments are made based on pre-analyzed positional information.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces simple geometric correction assumptions with a measurement-based approach. Instead of relying on mechanical or theoretical position relationships, the system uses actual sensor measurements of pattern positions and calculates distances to determine correction amounts, substituting physical assumptions with empirical data.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS10447893B2Image forming apparatus, computer-readable storage medium, and image forming method with position acquisition and correction

Publication Date: 2019.10.15 KK TOSHIBA

AI summary

An image forming apparatus includes a printer, a sensor, and a processor. The printer forms an image with image forming material of colors on a medium. The sensor detects the image forming material of each color on the medium. The processor forms a pattern with the image forming material of the colors on the medium using the printer, acquires a position of a pattern of each color using the sensor, and after executing correction for bringing positions where images of the other colors are formed close to a position where an image of a reference color is formed based on the position of each pattern, corrects a position where either an image of a first color or an image of a second color is formed by the printer based on a distance between patterns of the first color and second color furthest away from each other.