Hinged Imaging Unit Gap Control via Intermediary Positioning

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Solution Overview

Problem

Conventional electrophotographic imaging units face challenges in maintaining a consistent gap between the photoconductor drum and the developer roller due to misalignment, distortion, and high manufacturing costs for precise components, making it difficult to control and adjust this gap efficiently.

Innovation Solution

An electrophotographic imaging unit with a hinged dual-housing design, where the photoconductor and developer housings are connected by pivot pins, allowing for adjustable spacing between the photoconductor drum and the developer roller, with a support sandwiched between the housings to maintain alignment and a fastening mechanism using elastic components to secure the gap, enabling easy assembly and adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a hinged dual-housing design is used to allow easy assembly and disassembly, then ease of operation is improved, but manufacturing precision deteriorates because consistency of spacing cannot be ensured due to misalignment and distortion

Engineering Contradiction:

Improveease of assembly and disassemblyVSAvoidconsistency of spacing between photoconductor drum and developer roller

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

A positioning member is introduced as an intermediary component between the photoconductor housing and developer housing. This positioning member includes a positioning protrusion on one housing and a corresponding positioning recess on the other housing, which mate together to precisely define and maintain the spacing relationship between the photoconductor drum and developer roller, eliminating misalignment issues while preserving the hinged design's ease of assembly

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The spacing between the photoconductor drum and developer roller is controlled by changing the dimensional parameters of the positioning member, specifically the distance between the positioning protrusion and the reference surface. By precisely controlling this dimension, consistent spacing is achieved without requiring tight tolerances on the housing components themselves

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If tight dimensional and positional tolerances are required to ensure spacing consistency, then manufacturing precision is improved, but ease of manufacture deteriorates due to high costs of manufacturing components with high precision

Engineering Contradiction:

Improveconsistency of spacingVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The positioning member serves as a mediator that transfers the positioning function from the housing components to a dedicated, simple component. This allows the housings to be manufactured with relaxed tolerances while the positioning member, which can be made with precise dimensions through simple processes, ensures consistent spacing

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The positioning member is designed as a simple, inexpensive component that can be easily manufactured and replaced if needed. Rather than requiring expensive precision machining of the housing components, the positioning member provides the necessary precision at low cost, embodying the principle of using simple, replaceable parts to achieve precision

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Device complexity

If the drum-to-roller spacing is determined by integral contacting surfaces, then manufacturing complexity is reduced, but adaptability deteriorates because the spacing is hard to modify

Engineering Contradiction:

Improvesimplicity of contacting surface designVSAvoidability to modify spacing

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The spacing determination function is segmented from the integral housing structure and assigned to a separate positioning member. This segmentation allows the positioning member to be independently designed and modified without changing the housing structure, providing adaptability while maintaining the simplicity of the overall design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The positioning member is designed to be replaceable and adjustable, allowing the spacing to be dynamically modified by changing the positioning member or adjusting its dimensions. This provides versatility for different spacing requirements while keeping the housing structure simple and unchanged

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP2071416B1Imaging unit and image forming apparatus using same

Publication Date: 2019.03.06 RICOH CO LTD

Figure 1A~1B
Figure 2~3
Figure 4~5

AI summary

An electrophotographic imaging unit includes a photoconductor housing (3), a developer housing (6), and a support (5). The photoconductor housing is configured to rotatably support a photoconductor drum (1). The developer housing is configured to accommodate developer and a developer roller (4). The support is configured to rotatably support the developer roller at opposite ends thereof. The photoconductor housing and the developer housing are hinged (10) together at one side, and movable relative to each other at another side to open and close the imaging unit to sandwiched the support between the photoconductor housing and the developer housing when the imaging unit is closed. A fastening means (F) fastens the photoconductor housing and the developer housing together.