Development Roller Cam Control for Precise Drum Alignment

Solution Overview

Problem

Existing image forming apparatuses face challenges in accurately controlling the rotation of rotating cams, which can lead to excessive rotation and potential misalignment of development rollers with photosensitive drums.

Innovation Solution

The image forming apparatus incorporates a rotating cam with a wall that contacts the cam follower, restricting its rotation, and includes a motor that can rotate in both forward and reverse directions to control the movement of the development roller between contact and spaced positions, using a cam follower that moves along the rotation axis and is guided by inclined surfaces to maintain the cam's rotation within a predetermined range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the rotating cam is allowed to rotate freely to control the development roller movement, then the development roller can be positioned between contact and spaced positions, but the rotating cam may rotate excessively beyond the predetermined angular range leading to inaccurate control

Engineering Contradiction:

Improvedevelopment roller positioningVSAvoidcam rotation control accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-configuring the cam structure with protrusions and corresponding recesses in the housing that define and limit the rotational range of the cam before operation begins. This prevents excessive rotation from the outset rather than requiring corrective measures during operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary approach by introducing a housing with specifically designed recesses that act as mechanical guides and stoppers. These recesses mediate between the cam's rotational motion and the desired angular limits, ensuring the cam stays within the predetermined range through physical constraint rather than complex control systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the cam follower is designed to push the development cartridge for precise positioning, then the development roller can be accurately located, but the cam follower may fall off or become misaligned if the cam rotates excessively

Engineering Contradiction:

Improvedevelopment roller positioning precisionVSAvoidcam follower alignment

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-configuring the cam structure with protrusions and corresponding recesses in the housing that define and limit the rotational range of the cam before operation begins. This prevents excessive rotation from the outset rather than requiring corrective measures during operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary approach by introducing a housing with specifically designed recesses that act as mechanical guides and stoppers. These recesses mediate between the cam's rotational motion and the desired angular limits, ensuring the cam stays within the predetermined range through physical constraint rather than complex control systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This configuration effectively restricts excessive rotation of the rotating cam, ensuring precise alignment and movement of the development roller, enhancing the reliability and accuracy of the image forming process.

Implementation Method 1

The inclined surface pushes the cam follower in the direction of the rotation axis away from the first surface to move the cam follower from the non-pushing position to the pushing position

Methodology Applied

Scientific EffectInclined plane: Inclined Plane

Data Source

PatentUS20250306501A1Image forming apparatus

Publication Date: 2025.10.02 BROTHER KOGYO KK

AI summary

An image forming apparatus includes a photosensitive drum, a development cartridge, a motor, a rotating cam and a cam follower. The development cartridge includes a development roller that is movable between a contact position and a spaced position. The motor is rotatable in a forward direction and in a reverse direction. The rotating cam is rotatable in a forward direction and in a reverse direction by a driving force of the motor. The cam follower is configured to move in a direction of a rotation axis of the rotating cam in response to rotation of the rotating cam and to push the development cartridge to move the development roller between the contact position and the spaced position. The rotating cam includes a wall configured to contact the cam follower in a direction of rotation of the rotating cam to restrict the rotation of the rotating cam.