Image Forming Apparatus Color Stabilization via Spectrometer Feedback

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Solution Overview

Problem

Existing image forming apparatuses face challenges in stabilizing color output due to fluctuations in toner charge, requiring unnecessary test prints and increasing costs, especially when dealing with multi-color images where correcting primary color image forming conditions based on measured multi-colors is difficult.

Innovation Solution

An image forming apparatus that estimates and corrects the developing density of primary color images based on measured multi-colors, using a spectrometer to measure colors and a main controller to adjust control parameters such as toner density, developing bias, and laser intensity to stabilize color output without the need for test prints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If test toner images are printed to detect and stabilize toner adhesion amount, then color stability of toner images is improved, but printing costs increase and productivity decreases

Engineering Contradiction:

Improvecolor stabilityVSAvoidprinting productivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system uses the user's own printed images to perform color measurements and feedback control, eliminating the need for separate test prints. The image forming apparatus measures colors of images it produces and automatically adjusts developing conditions based on these measurements, making the system self-diagnosing and self-correcting without requiring additional test operations.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The color measurement function is integrated into the normal image forming process. The same image forming apparatus that produces user images also measures their colors and performs feedback control, making the test image formation and user image formation unified into a single multi-functional process rather than separate operations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If test toner images are printed to detect toner adhesion amount, then developing density fluctuations are suppressed, but overall printing costs increase

Engineering Contradiction:

Improvedeveloping density stabilityVSAvoidtoner consumption

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

Inventive Principle:

Principle #25Self-service

3Productivity

If colors of user images are measured to correct image forming conditions, then test print requirements are eliminated, but controlling primary color images based on multi-colors becomes difficult

Engineering Contradiction:

Improveprinting productivityVSAvoidcolor measurement and control difficulty

Core Design Contradiction:

ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The system segments the multi-color measurement data into individual primary color components (cyan, magenta, yellow, black). By measuring the colors of the composite image and mathematically separating the contributions of each primary color, the system can independently control each color channel based on feedback from multi-color measurements, making the control problem solvable despite the complexity of multi-color interactions.

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 approach effectively stabilizes color output by reducing the need for test prints, improving productivity, and accurately adjusting image forming conditions to achieve consistent multi-color images, thereby enhancing color stability and reducing overall printing costs.

Implementation Method 1

a spectrometer to measure colors

Methodology Applied

Scientific EffectSpectroscopy: Absorption Spectroscopy

Implementation Method 2

forms an electrostatic latent image on a photoconductor

Methodology Applied

Scientific EffectElectrostatics: Electrostatics

Implementation Method 3

primary-transfers the primary color toner images onto an intermediate transfer belt

Methodology Applied

Scientific EffectElectrostatic transfer: Electrostatic Deposition

Implementation Method 4

transferred to a recording sheet, and is then fixed

Methodology Applied

Scientific EffectThermal fixation: Heating

Data Source

PatentUS8705991B2Image forming apparatus, image forming control method, and recording medium storing image forming control program

Publication Date: 2014.04.22 RICOH CO LTD

AI summary

An image forming apparatus is provided with a measuring device, which measures multi-colors in a multi-color toner image formed on a recording sheet that is output from the image forming apparatus. Based on the measured multi-colors, the image forming apparatus estimates an output value of each one of primary color toner images that constitute the multi-color toner image, and corrects an image forming condition of each one of the primary color toner images based on comparison between the estimated output value of the primary color toner image and a target value of the primary color toner image.