Image Forming Apparatus Tone Calibration via Density Prediction

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Solution Overview

Problem

Current image forming apparatuses face challenges in maintaining accurate tone characteristics due to environmental variations and wear, leading to increased downtime during actual measurement calibration and lower accuracy in prediction calibration without frequent actual measurement updates.

Innovation Solution

The apparatus employs an image forming unit, sensor, and controller to form and detect pattern images of varying tone levels, using first and second calibration processes based on detection results and acquired information to generate image forming conditions, improving prediction accuracy by incorporating additional density data without the need for frequent actual measurement calibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If actual measurement calibration is executed frequently to improve tone characteristic accuracy, then measurement precision is improved, but loss of time increases due to increased downtime

Engineering Contradiction:
Improvetone characteristic accuracyVSAvoiddowntime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs prediction calibration in advance between actual measurement calibrations to maintain tone characteristics. By predicting density values based on stored actual measurement values and current image forming conditions, the system proactively corrects tone deviations without requiring frequent full actual measurement calibrations, thus reducing downtime while maintaining accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from actual measurement calibration results to update prediction models. The detection results from actual measurements are stored and used to refine future predictions, creating a continuous improvement loop where past measurement data enhances the accuracy of prediction calibration, allowing longer intervals between actual measurements.

Inventive Principle:
Principle #23Feedback

2Loss of time

If prediction calibration is used to reduce downtime, then loss of time is reduced, but measurement precision deteriorates due to lower correction accuracy

Engineering Contradiction:
ImprovedowntimeVSAvoidcorrection accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The system introduces an intermediary prediction mechanism that bridges actual measurement calibration and tone correction. Instead of directly correcting based on limited prediction data, the system uses prediction calibration as an intermediary step that leverages stored actual measurement values and current conditions to generate accurate correction values, achieving high accuracy without full actual measurement procedures.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the parameters used in calibration by incorporating multiple factors into prediction calibration: stored actual measurement values, current image forming conditions, and detection results. By dynamically adjusting prediction based on these parameter changes, the system achieves high correction accuracy comparable to actual measurement calibration while avoiding the downtime associated with frequent actual measurements.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the number of tone levels in pattern images is increased to improve calibration accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration process is segmented into two distinct phases: actual measurement calibration executed periodically to establish baseline accuracy, and prediction calibration executed between measurements to maintain accuracy. This segmentation allows the system to use full-tone-pattern actual measurements less frequently while using simplified prediction-based calibration more often, reducing overall complexity without sacrificing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs partial calibration actions through prediction calibration between full actual measurements. Instead of executing complete actual measurement calibration procedures frequently, the system performs partial corrections based on predictions, using only the necessary detection results and stored data, thereby reducing the complexity and time of frequent calibration operations while maintaining sufficient 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

This approach enhances prediction calibration accuracy while reducing downtime by utilizing additional density data, maintaining tone characteristics at target levels without the necessity for frequent actual measurement updates.

Implementation Method 1

a sensor configured to detect a pattern image formed by the image forming unit

Methodology Applied
Scientific EffectOptical detection: Photoelectric Effect

Data Source

PatentUS20240320456A1Image forming apparatus for creating image forming condition
Publication Date: 2024.09.26 CANON KK
  • US20240320456A1 patent drawing
  • US20240320456A1 patent drawing
  • US20240320456A1 patent drawing

AI summary

An image forming apparatus forms a first pattern image of a first number of tone levels, executes a first calibration for generating a first image forming condition based on a detection result of the first pattern image, forms a second pattern image of a second number of tone levels, acquires information having a correlation to a density of an image, and executes a second calibration for generating a second image forming condition based on the information, the detection result of the second pattern image, and the first image forming condition.