Developing Roller Pressing Mechanism for Image Forming Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses, when the developing cartridge is positioned below the photosensitive drum with the developing roller extending upwardly, there is a risk that the pressing force may lean or offset in the axis direction, compromising the balanced contact between the developing roller and the photosensitive drum.
Innovation Solution
An image forming apparatus design featuring a developing cartridge with a developing roller oriented upwardly, supported by a support body and pressed against the photosensitive drum via a pressing member that directly presses the rotation shaft or axis portion coaxial with the developing roller, ensuring balanced contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the developing cartridge is arranged below the photosensitive drum with the developing roller extending upwardly and the boss is pressed downwardly, then the developing roller can be pressed against the photosensitive drum, but the pressing force may lean or offset in the axis direction of the developing roller
Solution Approach 1:
Instead of pressing the boss downwardly from above the developing roller, the pressing member is positioned below the developing roller and presses upwardly. This inversion of the pressing direction ensures that the pressing force acts along the axis direction of the developing roller, preventing lateral offset and maintaining proper contact alignment with the photosensitive drum.
Solution Approach 2:
The pressing member acts as an intermediary between the support body and the developing roller's rotation shaft. By pressing the rotation shaft directly rather than the boss, the pressing member ensures that the force is transmitted centrally through the axis of the developing roller, preventing lateral forces and maintaining alignment.
2Reliability
If the boss is pressed downwardly to press the developing roller against the photosensitive drum, then contact is achieved, but the pressing force application point is away from the developing roller which may cause instability
Solution Approach 1:
The pressing function is extracted from the boss and applied directly to the rotation shaft of the developing roller. This eliminates the need for the boss to transmit pressing force, simplifying the mechanism while improving reliability by ensuring the pressing force is applied at the most effective and stable point.
Solution Approach 2:
The rotation shaft of the developing roller serves dual purposes: it supports the developing roller for rotation and provides the pressing surface for the pressing member. This self-service approach eliminates the need for separate pressing structures, reducing complexity while ensuring stable contact.
Data Source
AI summary
An image forming apparatus includes: a photosensitive body on which an electrostatic latent image is formed; a developing cartridge arranged below the photosensitive body and having a developing roller configured to supply a developing agent to the photosensitive body and to be rotatable about an rotation shaft of the developing roller; a support body configured to removably support the developing cartridge; and a pressing member configured to press the rotation shaft of the developing roller so as to press the developing roller against the photosensitive body.