Movable Spacer Cartridge Structure for Drum-Roller Separation

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Solution Overview

Problem

Conventional image forming apparatuses using electrophotographic processes face issues such as image defects, developer contamination, and accelerated deterioration of the developing roller due to prolonged contact between the developing roller and photosensitive drum, especially when the developing roller is not in use.

Innovation Solution

A cartridge design featuring a movable developing member that can transition between a developing position and a spaced position, utilizing a holding portion and urging portion to control the relative position between the developing member and photosensitive member, with external forces applied to move between these positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the developing roller is kept in contact with the photosensitive drum during non-image formation periods, then the developing roller maintains ready-to-use position, but image defects occur due to elastic layer deformation and developer contamination

Engineering Contradiction:

Improvereadiness of developing rollerVSAvoidimage quality

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The developing roller is designed to be movable between contact and spaced positions relative to the photosensitive drum. A holding portion movably supports the developing roller, enabling it to dynamically adjust its position based on operational requirements, thus resolving the contradiction between maintaining readiness and preventing image defects

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The urging portion applies a predetermined urging force to the holding portion, preliminarily positioning the developing roller in the spaced position to prevent elastic layer deformation and developer contamination before image formation begins. This preliminary anti-action eliminates the conditions that cause image defects

Inventive Principle:

Principle #9Preliminary anti-action

2Device complexity

If the developing roller contacts the photosensitive drum during non-development periods, then component wear is accelerated due to prolonged rubbing, but maintaining contact simplifies the mechanism

Engineering Contradiction:

Improvemechanism simplicityVSAvoidcomponent durability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The developing roller is extracted from continuous contact with the photosensitive drum during non-development periods. By spacing the developing roller from the photosensitive drum when not in use, prolonged rubbing is eliminated, preventing accelerated deterioration of both the developing roller and the photosensitive drum

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If the developing roller is spaced from the photosensitive drum during non-image formation, then image quality is maintained, but additional positioning mechanisms are required

Engineering Contradiction:

Improveimage qualityVSAvoidpositioning mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The urging portion automatically maintains the developing roller in the spaced position through its inherent urging force, without requiring external control mechanisms. The holding portion self-adjusts to position the developing roller appropriately, enabling the system to maintain image quality while minimizing structural complexity

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The holding portion serves multiple functions: it movably supports the developing roller, responds to the urging force from the urging portion, and enables the developing roller to assume both spaced and contact positions as needed. This multi-functionality reduces the need for separate positioning mechanisms

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

Prevents unintended developer deposition and reduces wear by spacing the developing roller from the photosensitive drum during non-use, thereby minimizing image defects and extending the lifespan of the developing roller.

Implementation Method 1

an urging portion (153) capable of applying, to the second unit (109), an urging force for urging the second unit (109) toward the developing position

Methodology Applied

Scientific EffectElastic force: Elasticity

Data Source

PatentUS12632003B2Cartridge having movable spacer for restricting movement of a first frame relative to a second frame

Publication Date: 2026.05.19 CANON KK

AI summary

A cartridge includes a photosensitive member, a charging member configured to charge the photosensitive member, a first unit including the photosensitive member and the charging member, a developing member configured to deposit toner onto the photosensitive member, and a second unit including the developing member. A holding portion is movably supported by the first unit or the second unit, with the holding portion being configured to restrict a relative position between the first unit and the second unit, the holding portion being movable between a first position for holding the second unit in a spaced position by the first unit and a second position for holding the second unit in a developing position by the first unit. An urging portion including a force receiving portion capable of receiving an external force, with the urging portion being capable of applying, to the second unit, an urging force for urging the second unit toward the developing position while receiving the external force at the force receiving portion.