Image Density Calibration via Coverage Rate Adjustment Patch

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Solution Overview

Problem

In electrophotographic image forming apparatuses, the fixed coverage rate of calibration image patterns can lead to inaccurate density adjustments during calibration when the coverage rate of user print images differs, causing fluctuations in toner charge and development characteristics.

Innovation Solution

An image forming apparatus that includes a coverage rate measurement unit to measure the coverage rate of user print images and a calibration execution unit to form a coverage rate adjustment patch, ensuring accurate image density adjustment by matching the coverage rate with the adjustment image pattern, thereby stabilizing toner charge and improving image density characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a fixed coverage rate calibration image pattern is used, then the calibration process is simple and quick, but the density adjustment accuracy deteriorates when user print image coverage rate differs

Engineering Contradiction:

Improvecalibration timeVSAvoiddensity adjustment accuracy

Core Design Contradiction:

Loss of timeVSManufacturing precision

Solution Approach 1:

The system performs preliminary measurement of the user print image coverage rate before calibration, and prepares a coverage rate adjustment patch with appropriate coverage rate in advance. This preliminary action ensures that the calibration process uses the correct coverage rate from the start, eliminating the need for iterative adjustments and maintaining both speed and accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the coverage rate parameter of the calibration image pattern to match the user print image coverage rate. By dynamically adjusting this parameter rather than using a fixed value, the system maintains density adjustment accuracy across different printing scenarios while keeping the calibration process efficient.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If calibration is performed with different coverage rate, then calibration speed is maintained, but toner charge amount fluctuates and development characteristics change

Engineering Contradiction:

Improvecalibration speedVSAvoiddevelopment characteristic stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system dynamically changes the coverage rate parameter of the calibration image pattern to match the actual user print conditions. This ensures that the toner charge amount and development characteristics remain consistent between calibration and actual printing, maintaining reliability without sacrificing calibration speed.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from the measured user print image coverage rate to adjust the calibration image pattern coverage rate. This feedback mechanism ensures that the calibration process reflects actual printing conditions, stabilizing development characteristics while maintaining efficient calibration speed.

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If coverage rate adjustment patch is formed, then density adjustment accuracy is improved, but calibration process complexity increases

Engineering Contradiction:

Improvedensity adjustment accuracyVSAvoidcalibration process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The coverage rate adjustment patch is prepared in advance based on preliminary measurement of user print image coverage rate. This preliminary preparation simplifies the actual calibration process by having the correct adjustment patch ready, avoiding complex real-time calculations and adjustments during calibration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The calibration process is segmented into distinct components: measurement of user print coverage rate, calculation of required adjustment, formation of coverage rate adjustment patch, and execution of density adjustment. This segmentation makes each step straightforward and manageable, reducing overall process complexity while maintaining accuracy.

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 solution ensures accurate image density adjustment and improved image quality by stabilizing the toner charge during calibration, resulting in enhanced image density characteristics for subsequent print images.

Implementation Method 1

an exposure device that irradiates the photosensitive drum with light to form an electrostatic latent image

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

a developing device that performs development by causing toner to adhere to the electrostatic latent image

Methodology Applied

Scientific EffectElectrostatic Deposition: Electrostatic Deposition

Data Source

PatentUS11550251B2Image forming apparatus

Publication Date: 2023.01.10 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

An image forming apparatus forms a coverage rate adjustment patch having a coverage rate corresponding to a difference between a coverage rate measured by a coverage rate measurement unit and a coverage rate of an adjustment image pattern together with an adjustment image pattern by using the exposure device and the developing device in the calibration.