Developing Sleeve Regulating Blade Gap for Uniform Toner Coating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Variations in the local maximum peak value and position of magnetic flux density of the regulating pole in developing devices lead to inconsistent developer coat amounts, causing variations in image quality across different devices.

Innovation Solution

Adjust the size of the SB gap with consideration for the local maximum peak value and position of magnetic flux density of the regulating pole to stabilize the developer coat amount, ensuring uniformity across individual developing devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the size of the SB gap is set at the same value for all developing devices, then the device complexity is reduced and ease of manufacture is improved, but the developer coat amount varies due to variations in local maximum peak value and position of magnetic flux density of the regulating pole

Engineering Contradiction:
Improveease of manufactureVSAvoiddeveloper coat amount consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by adjusting the SB gap size based on the measured local maximum peak value and position of magnetic flux density for each regulating pole. Instead of using a fixed SB gap value for all developing devices, the method dynamically changes the SB gap parameter to compensate for magnetic field variations, thereby maintaining consistent developer coat amount across different devices while accounting for manufacturing tolerances in magnet production

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the SB gap is adjusted for each individual magnet based on local maximum peak value and position, then the developer coat amount consistency is improved, but the device complexity and manufacturing time increase

Engineering Contradiction:
Improvedeveloper coat amount consistencyVSAvoidadjustment process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by measuring the local maximum peak value and position of magnetic flux density before final assembly, and pre-determining the appropriate SB gap size for each regulating pole. This advance measurement and calculation allows the system to compensate for magnetic variations without adding complex real-time adjustment mechanisms during operation, thereby improving developer coat consistency while limiting the increase in device complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method incorporates feedback by using the measured magnetic flux density characteristics to determine the optimal SB gap setting. The measurement results feed back into the gap adjustment decision, creating a closed-loop system that automatically compensates for magnet variations. This feedback mechanism achieves high precision in developer coat amount while maintaining relatively simple device architecture

Inventive Principle:
Principle #23Feedback

3Ease of operation

If a fixed SB gap is used without considering magnetic flux density variations, then the ease of operation is improved, but the reliability of image quality across different devices deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidimage quality consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by performing magnetic flux density measurements and SB gap calculations during the manufacturing or setup phase, before the device enters normal operation. This preliminary configuration ensures that each developing device is pre-optimized for its specific magnet characteristics, thereby maintaining ease of operation during use while achieving reliable image quality consistency across different devices

Inventive Principle:
Principle #10Preliminary 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 adjustment method reduces variations in developer coat amount, enhancing image quality consistency and reliability across different developing devices.

Implementation Method 1

a magnet (71) having a plurality of magnetic poles

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

The magnet roll is a magnet (71) having a plurality of magnetic poles

Methodology Applied
Scientific EffectMagnetism: Magnetism

Implementation Method 3

The regulating pole has a local maximum peak value of magnetic flux density at a position which is on the upstream side of the regulating blade

Methodology Applied
Scientific EffectMagnetic flux density: Magnetic Field

Implementation Method 4

the magnitude of a magnetic force acting on a carrier contained in a developer having contact with the upstream side of the regulating blade

Methodology Applied
Scientific EffectMagnetic force: Lorentz Force

Data Source

PatentEP4006645B1Method for fixing regulating blade and developing device
Publication Date: 2026.03.11 CANON KK
  • EP4006645B1 patent drawingFigure 1
  • EP4006645B1 patent drawingFigure 2
  • EP4006645B1 patent drawingFigure 3

AI summary

A magnet roll provided non-rotatably and stationarily inside a rotatable developer carrying member (70) for carrying and feeding a developer to a developing position is disclosed. The magnet roll comprises: a magnet (71); and a shaft configured to fix the magnet (71). The magnet roll is provided with information regarding magnetic flux density of the magnet (71). A developer carrying member (70) configured to carry and feed a developer to a developing position is also disclosed. The developer carrying member (70) comprises: a rotatable sleeve; and a magnet (71) provided non-rotatably and stationarily inside the rotatable sleeve. The developer carrying member (70) is provided with information regarding magnetic flux density of the magnet (71).