Superimposed Black Developer Pattern for Registration Correction

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Solution Overview

Problem

Existing color image forming apparatuses face challenges in accurately correcting misregistration among colors, especially when using black as a reference color, as black patterns cannot be detected using diffuse reflected light, leading to errors in registration correction and increased toner consumption.

Innovation Solution

A color image forming apparatus that forms a superimposed pattern with black developer as a background color, using a detector to calculate the deviation between color and black developer positions based on diffuse reflected light, allowing for accurate adjustment of image forming conditions to correct misregistration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If black developer is used as reference color for registration correction, then registration accuracy is improved, but detection precision deteriorates because black patterns cannot be detected using diffuse reflected light

Engineering Contradiction:

Improveregistration accuracyVSAvoiddetection precision

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent introduces a light receiving unit that detects diffuse reflected light from the intermediate transfer member as an intermediary mechanism. By detecting the diffuse reflected light pattern rather than directly detecting the black developer pattern, the system enables registration correction using black reference patterns while overcoming the detection difficulty of black colors.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the detection parameter from direct pattern detection to diffuse reflected light detection. This parameter change allows the system to detect black patterns indirectly through their effect on diffuse reflected light, resolving the contradiction between using black as reference color and being able to detect it.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If sensors for beam detection are reduced to lower cost, then device complexity is reduced, but measurement precision deteriorates due to accumulation of errors in pseudo BD signal generation

Engineering Contradiction:

Improvenumber of sensorsVSAvoidhorizontal synchronizing signal accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses the intermediate transfer member as a mediator to generate horizontal synchronizing signals. By detecting diffuse reflected light from the intermediate transfer member, the system can generate accurate BD signals without requiring separate sensors for each color station, thus reducing the number of sensors while maintaining precision.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The intermediate transfer member serves multiple functions: it acts as both the transfer medium for color images and as the reference for generating horizontal synchronizing signals. This multi-functionality eliminates the need for separate sensor systems, reducing device complexity while maintaining measurement precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Manufacturing precision

If black developer pattern is superimposed on color developer pattern, then registration correction becomes possible with diffuse reflected light, but toner consumption increases

Engineering Contradiction:

Improveregistration correction capabilityVSAvoidtoner consumption

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent applies the superimposed pattern technique only in the necessary local areas for registration correction, rather than applying it universally across the entire image area. This localized application minimizes toner consumption while maintaining registration correction capability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses partial action by forming detection patterns only in specific regions needed for registration correction. The superimposed black pattern is applied minimally and only where required for detection, avoiding excessive toner usage while achieving the necessary registration accuracy.

Inventive Principle:

Principle #16Partial or excessive action

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

Enables efficient registration correction using diffuse reflected light, even with developers that have a small reflected component, reducing toner consumption and maintaining registration accuracy, while allowing for miniaturization of the apparatus.

Implementation Method 1

a detector configured to irradiate the superimposed pattern with light and detect diffuse reflected light

Methodology Applied

Scientific EffectDiffuse reflection: Reflection

Data Source

PatentUS8036552B2Method for correcting registration errors by superimposing a black developer on a background of a color

Publication Date: 2011.10.11 CANON KK

AI summary

A color image forming apparatus causes a light emitting unit to emit light to a superimposed pattern in which a black developer (Bk) is superimposed on a color developer (Y, M, C) as a background color, detects diffuse reflected light by a light receiving unit, calculates positional deviation among the colors using the black developer (Bk) as a reference color based on a detection result, and adjusts an image forming condition.