Developing Frame Pressure-Receiving Wall for Pressing Force Retention

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Solution Overview

Problem

The existing process cartridges experience a loss in pressing force due to deformation of the drum frame when the pressing members react to the developing cartridge, especially when pressing the end portion of the developing frame far from the photosensitive drum.

Innovation Solution

The process cartridge design includes a pressure-receiving wall in the developing frame that surrounds the supply roller shaft, allowing the pressing member to press this wall instead of the end portion of the developing frame far from the photosensitive drum, thus maintaining a closer pressing position near the photosensitive drum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the pressing members press the end portion of the developing frame far from the photosensitive drum, then the developing cartridge can be pressed toward the photosensitive drum, but the drum frame deforms due to reaction force causing loss in pressing force

Engineering Contradiction:
Improvepressing forceVSAvoidloss in pressing force
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

A reaction force receiving portion is provided on the developing frame to serve as an intermediary structure. This portion receives the reaction force from the pressing members and transmits it to the drum frame at a position closer to the photosensitive drum, thereby reducing the lever arm and minimizing drum frame deformation while maintaining effective pressing force on the developing cartridge.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Force

If the pressing members press positions close to the photosensitive drum, then the loss of pressing force due to drum frame deformation is reduced, but the developing cartridge structure becomes more complex

Engineering Contradiction:
Improvepressing force efficiencyVSAvoiddeveloping frame structure
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The reaction force receiving portion is integrated into the existing developing frame structure, serving multiple functions: it provides a pressing reaction force reception point closer to the photosensitive drum, maintains structural support for the developing cartridge, and simplifies the overall design by combining these functions into a single structural element rather than adding separate components.

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

Data Source

PatentEP4542308A1Process cartridge
Publication Date: 2025.04.23 BROTHER KOGYO KK
  • EP4542308A1 patent drawingFigure 1
  • EP4542308A1 patent drawingFigure 2
  • EP4542308A1 patent drawingFigure 3A~3B

AI summary

A process cartridge (5) includes: a drum cartridge (6); and a developing cartridge (7) attachable to and detachable from the drum cartridge. The drum cartridge includes: a photosensitive drum (61) rotatable about a drum axis (61X) extending in a first direction; and a pressing member (150A, 150B) pressing the developing cartridge toward the photosensitive drum in a state where the developing cartridge is attached to the drum cartridge. The developing cartridge includes: a developing roller (71) rotatable about a developing-roller axis extending in the first direction; a supply roller (72) including a supply roller shaft (72A) extending in the first direction; and a developing frame. The developing frame includes: a side wall (210A, 210B) positioned at one end in the first direction of the developing frame; and a pressure-receiving wall (220A, 220B, 210A, 221, 222, 223, 210B) protruding in the first direction from the side wall. In the state where the developing cartridge is attached to the drum cartridge, the pressure-receiving wall is pressed by the pressing member.