Developing Cartridge Cam Mechanism for Single-Sided Roller Separation

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Solution Overview

Problem

Conventional image-forming apparatuses require driving force to be applied to both sides to separate the developing roller from the photosensitive drum, which is inefficient and inconvenient.

Innovation Solution

A developing cartridge design featuring a first cam with inclined surfaces and a resilient member that allows the developing roller to be separated from the photosensitive drum using a driving force applied from only one side, utilizing a cam mechanism and resilient member to move the roller between contact and separation positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If driving force is applied to both sides to separate the developing roller from the photosensitive drum, then reliable separation is achieved, but device complexity and operational effort increase

Engineering Contradiction:
Improveseparation reliabilityVSAvoiddriving mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cam mechanism is designed with asymmetric geometry where only one cam (first cam) is required to perform the separation function. The cam profile includes inclined surfaces that convert single-sided driving force into bidirectional movement of the developing roller, eliminating the need for symmetric dual-sided actuation while maintaining reliable separation

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The cam acts as an intermediary mechanism that transforms the driving force applied from one side into the necessary bidirectional motion for separating and contacting the developing roller with the photosensitive drum. The inclined surfaces of the cam profile serve as the mediation interface between the single driving force source and the dual-directional movement requirement

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If driving force is applied to both sides for roller separation, then balanced movement is achieved, but ease of operation deteriorates

Engineering Contradiction:
Improvemovement balanceVSAvoidoperational convenience
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The operational interface is simplified to single-sided actuation through the cam mechanism. The asymmetric cam profile inherently balances the movement by distributing the force transmission appropriately, allowing one-sided operation while maintaining stable and balanced roller separation and contact

Inventive Principle:
Principle #4Asymmetry

3Reliability

If dual-sided driving force application is used, then complete roller separation is achieved, but productivity decreases

Engineering Contradiction:
Improveseparation completenessVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The separation function is extracted and consolidated into a single cam mechanism that handles all separation requirements from one side. This eliminates the need for dual-sided actuation components and operations, achieving complete roller separation while improving operational efficiency by reducing the number of actuation points from two to one

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cam mechanism is designed to automatically perform the separation and contact functions through its geometric profile. When driven from one side, the cam's inclined surfaces self-generate the necessary bidirectional forces to move the developing roller into contact or separation from the photosensitive drum without requiring additional actuation from the other side

Inventive Principle:
Principle #25Self-service

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

Enables efficient separation of the developing roller from the photosensitive drum using a single-sided driving force, improving operational efficiency and reducing the need for dual-sided force application.

Implementation Method 1

The first cam has a first inclined surface and a second inclined surface. The first inclined surface is configured to receive a pressing force directing from one end portion of the casing in the first direction toward another end portion of the casing in the first direction. The first cam is movable between the first position and the second position in response to application of the pressing force to the first inclined surface.

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

a first resilient member urging the first cam toward the first position from the second position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3948427B1Developing cartridge
Publication Date: 2024.03.06 BROTHER KOGYO KK
  • EP3948427B1 patent drawingFigure 1
  • EP3948427B1 patent drawingFigure 2
  • EP3948427B1 patent drawingFigure 3

AI summary

A developing cartridge 1 includes: a developing roller 30 rotatable about an axis extending in a first direction; a casing 10; and a first cam 61 provided at an outer surface of one end portion of the casing 10 in a second direction. The first cam 61 is movable in a third direction, relative to the casing 10 and the developing roller 30, between a first position and a second position closer to the developing roller 30 than the first position is to the developing roller 30 in the third direction. The first cam 61 has a first inclined surface 61a and a second inclined surface 61b. The first inclined surface 61a receives a pressing force F in the first direction directing from one end portion of the casing to another end portion of the casing in the first direction. A distance between the second inclined surface 61b and the casing 10 in the second direction varies as the second inclined surface 61b extends away from the developing roller 30 in the third direction. The first cam 61 is movable between the first position and the second position in response to application of the pressing force F to the first inclined surface 61a.