Merged Cam Mechanism for Developing Roller Contact

Solution Overview

Problem

Conventional color laser printers require multiple pressing and separating cams for each developing cartridge, increasing the number of parts and production costs.

Innovation Solution

A process unit with a first frame mounting photosensitive bodies and detachable developing units, where a movable second frame positions developing rollers to contact or separate from photosensitive bodies, reducing the number of components and maintaining a simple structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If pressing cams and separating cams are provided for each developing cartridge, then the developing rollers can be brought into and out of contact with the photosensitive drums, but the number of parts increases and production costs increase

Engineering Contradiction:

Improvecontact and separation of developing rollersVSAvoidnumber of parts

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the pressing and separating functions into a single cam mechanism. The cam has a pressing portion that presses the developing cartridge against the photosensitive drum during image formation, and a separating portion that separates them when not in use. This merging of functions reduces the number of parts while maintaining the ability to contact and separate developing rollers effectively

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single cam structure serves multiple functions: it acts as both a pressing cam and a separating cam for multiple developing cartridges. The cam mechanism is designed to interact with multiple developing cartridges simultaneously or sequentially, providing universal functionality across different color stations (yellow, magenta, cyan, black) without requiring dedicated cams for each cartridge

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If pressing cams and separating cams are provided for each developing cartridge, then the developing rollers can be brought into and out of contact with the photosensitive drums, but production costs increase

Engineering Contradiction:

Improvecontact and separation of developing rollersVSAvoidproduction costs

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The patent combines the pressing and separating functions into a single cam mechanism. The cam has a pressing portion that presses the developing cartridge against the photosensitive drum during image formation, and a separating portion that separates them when not in use. This merging of functions reduces the number of parts while maintaining the ability to contact and separate developing rollers effectively

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single cam structure serves multiple functions: it acts as both a pressing cam and a separating cam for multiple developing cartridges. The cam mechanism is designed to interact with multiple developing cartridges simultaneously or sequentially, providing universal functionality across different color stations (yellow, magenta, cyan, black) without requiring dedicated cams for each cartridge

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS8948652B2Image forming apparatus and process unit that form images by using photosensitive bodies and developing units

Publication Date: 2015.02.03 BROTHER KOGYO KK

AI summary

In an image forming apparatus, photosensitive bodies are mounted in a first frame. Developing units are detachably mounted in the first frame. A second frame is movable relative to the first frame. Each developing unit is movable relative to the first frame between a separate position, at which a developing roller is separate from a photosensitive body, and a contact position, at which the developing roller is in contact with the photosensitive body. The second frame moves relative to the first frame, thereby moving the developing units relative to the first frame between the separate positions and the contact positions. The second frame positions each developing unit relative to the first frame in a direction to move the developing roller toward the corresponding photosensitive body when the developing unit is in the contact position.