Photoconductor Reverse Rotation for Cleaning Unit Replacement

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Solution Overview

Problem

In image forming apparatuses, deposits such as residual toner and surplus lubricant can be sandwiched between the cleaning blade or leveling blade and the photoconductor when a new detachable unit is mounted, leading to gaps that cause image failures due to incomplete contact and potential adherence of substances to other components.

Innovation Solution

A position change mechanism that reverses the rotation direction of the photoconductor when replacing the cleaning unit, ensuring the deposit is moved away from the contact points, preventing sandwiching and allowing normal contact for proper function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If a detachable cleaning unit is removed and reattached, then maintenance and replacement are facilitated, but deposits become sandwiched between the contact member and photoconductor causing image failures

Engineering Contradiction:

Improvemaintenance and replacementVSAvoidimage quality

Core Design Contradiction:

Ease of repairVSReliability

Solution Approach 1:

The photoconductor is rotated in reverse direction before the detachable unit is reattached to move deposits away from contact points. This preliminary action prevents deposits from being sandwiched between the contact member and photoconductor during the mounting process, thereby maintaining image quality while still allowing easy replacement.

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If the photoconductor rotates in normal direction during unit replacement, then the replacement process is simple, but deposits are moved toward contact points causing sandwiching

Engineering Contradiction:

Improvereplacement processVSAvoidcontact quality

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The photoconductor rotation direction is inverted (rotated in reverse direction) during the unit replacement process. This inversion moves deposits away from the contact points instead of toward them, preventing sandwiching and ensuring proper contact quality while maintaining operational simplicity.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If deposits remain on photoconductor surface, then the cleaning unit can be quickly replaced, but the contact member cannot achieve normal contact function

Engineering Contradiction:

Improvereplacement speedVSAvoidcontact function

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Before the detachable unit is reattached, the photoconductor is rotated in reverse direction to perform a preliminary action of moving deposits away from contact points. This ensures that when the unit is quickly replaced, the contact member can achieve normal contact function without being obstructed by sandwiched deposits.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3324243B1Image forming unit and image forming apparatus

Publication Date: 2019.04.10 RICOH CO LTD

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AI summary

An image forming unit (1) includes an image bearer (2) to bear a toner image on a surface, and a detachable unit (200) having a contact member (50) and (62) disposed in contact with the surface of the image bearer (2). The detachable unit (200) being attachable and detachable from a support frame (22) to support the image bearer (2). The image forming unit (1) has a position change mechanism (70) to change a position in a rotation direction of the image bearer (2) by rotating the image bearer (2) in a reverse direction opposite to a direction of rotation of the image bearer (2) in image formation before attachment of the detachable unit (200) to the support frame (22).