Developer Cartridge Electrode Layout for Stable Toner Transfer

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Solution Overview

Problem

The existing developing cartridge in image forming apparatuses, such as laser printers, lacks improvements in the design of the developing roller and electrode configuration, which affects the efficiency and effectiveness of toner transfer.

Innovation Solution

The developing cartridge is redesigned with a specific configuration that includes a developing roller, a blade, and a developing electrode positioned in a manner that enhances toner transfer efficiency by optimizing the electrical connections and spatial arrangement of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the developing electrode is positioned close to the developing roller, then the electrical connection is improved, but the electrode may interfere with the blade and toner transfer process

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidcomponent spatial arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The developing electrode is repositioned from a conventional location to extend in the axial direction of the developing roller, utilizing the third dimension (axial direction) to achieve proper electrical connection without interfering with the radial blade and toner transfer path. This dimensional repositioning allows the electrode to contact the shaft at its end portion while extending parallel to the roller axis, clearing the operational space of the blade.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the contact surface of the developing electrode is positioned far from the blade, then the electrical connection stability is improved, but the electrode length and device complexity increase

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoiddeveloping electrode length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The developing electrode is divided into functionally distinct portions: a connection portion that contacts the shaft end portion for electrical connection, and a contact surface portion that extends in the axial direction to provide stable electrical contact. This segmentation allows each portion to be optimized independently - the connection portion ensures reliable connection while the contact surface portion provides stability without excessive length.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the developing electrode configuration is optimized for electrical connection, then the toner transfer efficiency is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvetoner transfer efficiencyVSAvoidelectrode manufacturing ease
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The developing electrode is designed to perform multiple functions simultaneously: it provides electrical connection to the developing roller shaft, maintains stable electrical contact during operation, and does so with a simple elongated structure that can be manufactured using conventional methods. The electrode's ability to fulfill multiple roles with a single simple component reduces overall manufacturing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The new configuration improves toner transfer efficiency and reliability, ensuring consistent and high-quality image output in image forming apparatuses.

Implementation Method 1

toner is carried onto the outer circumferential surface of the developing roller by the electrostatic force generated by the voltage supplied to the shaft

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP4682638A1Developer cartridge
Publication Date: 2026.01.21 BROTHER KOGYO KK
  • EP4682638A1 patent drawingFigure 1
  • EP4682638A1 patent drawingFigure 2
  • EP4682638A1 patent drawingFigure 3

AI summary

There is provided a new developing cartridge that is a further advancement of the existing technology. A developing cartridge 1 includes: a housing 10, a developing roller 30, and a developing electrode 60. The housing 10 has one end portion 13 and an other end portion 14 in a first direction. The developing roller 30 includes a developing shaft 32 extending in a second direction. The developing electrode 60 includes a first bearing hole 61 and a contact surface 64. The first bearing hole 61 is electrically connected to an end portion of the developing shaft 32 in the second direction. The contact surface 64 is positioned apart from the first bearing hole 61 in a third direction.