Color Registration Adjustment via Concurrent Luminance Setting and Contamination Detection

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Solution Overview

Problem

Conventional image forming apparatuses require separate operations to set luminance for registration sensors and detect contaminated areas, leading to increased time and potential inaccuracies in color registration due to misalignment and contamination issues.

Innovation Solution

An image forming apparatus and method that concurrently detect areas with undesirable surface conditions during luminance setting for the registration sensor, allowing for simultaneous optimization of luminance and exclusion of contaminated areas, using PI or PID control to adjust and stabilize sensor luminance, thereby facilitating accurate color registration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If separate operations are used to set luminance for registration sensors and detect contaminated areas, then each operation can be performed independently, but the overall time for color registration increases

Engineering Contradiction:
Improvetime for color registrationVSAvoidoperational complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent combines the luminance setting operation and the contaminated area detection operation into a single integrated process. Both operations are performed simultaneously during one rotation of the image forming medium, rather than sequentially. This merging eliminates the time waste of rotating the medium multiple times while maintaining operational independence through software coordination.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent ensures continuous useful action by performing both luminance setting and contaminated area detection without interruption during a single rotation of the image forming medium. The registration sensor continuously monitors both the luminance values and the reflected light patterns that indicate contamination, maximizing the utility of each rotation cycle.

Inventive Principle:
Principle #20Continuity of useful action

2Illumination intensity

If the luminance of the registration sensor is higher than a preset value, then more light is available for detection, but part of the registration pattern may not be perceived

Engineering Contradiction:
Improveluminance of registration sensorVSAvoiddetection accuracy of registration pattern
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The patent employs feedback control where the registration sensor detects the actual luminance and the reflected light from the registration pattern, and this information is used to adjust the sensor output or interpretation. The system monitors the reflected light intensity and uses this feedback to determine both the optimal luminance setting and the presence of contaminants, ensuring accurate pattern perception across varying luminance conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the operational parameters of the registration sensor based on detected conditions. By monitoring the reflected light intensity and comparing it against expected values, the system can adaptively change the luminance threshold or detection sensitivity to maintain accurate registration pattern perception regardless of whether the sensor luminance is high or low.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If the luminance of the registration sensor is lower than the preset value, then less light is emitted, but contaminants within the transfer belt may be perceived as part of the pattern

Engineering Contradiction:
Improveluminance of registration sensorVSAvoiddetection accuracy of registration pattern
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The feedback mechanism allows the system to detect when contaminants are being misperceived by comparing the reflected light signal against expected patterns. When luminance is low and contaminants create false signals, the feedback loop identifies these anomalies and adjusts the detection thresholds or triggers a re-detection at different luminance levels to eliminate false positives.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs detection with varying degrees of luminance intensity. By occasionally using higher luminance than the minimum required, the system can overcome the problem of contaminant misperception that occurs at low luminance levels. This partial excessive action ensures that even when operating at low power settings, the system periodically verifies accurate pattern detection by temporarily increasing luminance.

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

This approach reduces the overall time for color registration by overlapping the processes of setting optimal luminance and detecting surface conditions, ensuring precise alignment and minimizing the impact of contaminants on image quality.

Implementation Method 1

The registration sensor irradiates light onto a registration pattern developed on the image forming medium, and measures error in the image alignment by detecting the reflected light.

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

using PI or PID control to adjust and stabilize sensor luminance

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP2523449B1Image forming apparatus and method for color registration adjustment
Publication Date: 2020.01.08 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2523449B1 patent drawingFigure 1
  • EP2523449B1 patent drawingFigure 2~3
  • EP2523449B1 patent drawingFigure 4(a)~4(c)

AI summary

A method for color registration includes determining if color registration is necessary, and if color registration is necessary, rotating an image forming medium and setting an optimum luminance of a registration sensor with respect to a rotating surface of the image forming medium, confirming an area with an undesirable surface condition on the image forming medium using luminance detected with respect to the rotating surface of the image forming medium during the setting of the optimum luminance, forming a preset mark for color registration adjustment excluding the area confirmed to have an undesirable surface condition, and carrying out color registration adjustment using the optimum luminance set with respect to the formed mark.