Concave Guide Member for Recording Sheet Bowing Absorption

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Solution Overview

Problem

Conventional image-forming devices require a large number of parts to absorb the bowing of recording sheets upstream of the registration rollers, which increases complexity and cost.

Innovation Solution

An image-forming device with a concaved part on the process cartridge's lower wall, which absorbs the bowing of the recording sheet without the need for additional parts, allowing the existing registration rollers to function effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional guide members with multiple parts (upstream guide, downstream guide, coil spring) are used to absorb recording sheet bowing, then the bowing absorption function is achieved, but the device complexity and number of parts increase

Engineering Contradiction:
Improvebowing absorption capabilityVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the functions of the upstream guide, downstream guide, and coil spring into a single integrated guide member structure. This guide member has an elastic portion that can deform to absorb bowing and a pressing portion that contacts the recording sheet, eliminating the need for separate components while maintaining the bowing absorption function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide member is designed to perform multiple functions simultaneously: it guides the recording sheet through its structural form, absorbs bowing through elastic deformation of its portion, and applies pressing force through its pressing portion. This multi-functional design reduces the overall number of components needed in the system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple guide members and springs are installed upstream of registration rollers, then recording sheet guidance is improved, but manufacturing cost and assembly complexity increase

Engineering Contradiction:
Improverecording sheet guidance accuracyVSAvoidassembly complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent integrates multiple functions into a single guide member component that can be manufactured as one piece. This reduces assembly complexity while maintaining the guidance accuracy function through the guide member's structural design and elastic deformation capabilities.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If the guide member is positioned close to the photosensitive drum, then space utilization is improved, but the concaved part may be shaved by the recording sheet leading to wear

Engineering Contradiction:
Improvespace utilizationVSAvoidservice life of guide member
Core Design Contradiction:
Volume of moving objectVSDuration of action of stationary object

Solution Approach 1:

The guide member is designed as a replaceable component that can be easily swapped out when worn. By making it simple to replace rather than designing for extreme durability, the system accepts periodic replacement of this lower-cost component to maintain overall system performance and space efficiency.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 design reduces the number of parts required for bowing absorption, simplifies the device, and ensures reliable sheet conveyance without skewing or bending, while allowing for easy maintenance by replacing only the photosensitive unit when the concaved part is shaved.

Implementation Method 1

the guide member includes an upstream guide, a downstream guide, and a coil spring. The upstream guide is an elastic thin plate whose free end is disposed at the downstream. When a recording sheet conveyed from a feeding tray bows in a direction orthogonal to a surface of the recording sheet by contacting the pair of registration rollers, the guide member is elastically deformed to absorb the bowing of the recording sheet.

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2372460B1Image-forming device
Publication Date: 2019.02.13 BROTHER KOGYO KK
  • EP2372460B1 patent drawingFigure 1
  • EP2372460B1 patent drawingFigure 2
  • EP2372460B1 patent drawingFigure 3

AI summary

An image-forming device includes a casing, a conveying path, a pair of registration rollers, and a process cartridge. The conveying path is disposed in the casing to convey a recording sheet. The pair of registration rollers is disposed on the conveying path to regulate a leading edge of the recording sheet conveyed along the conveying path. The process cartridge is detachably mounted on the casing, and includes a developer accommodating unit, a photosensitive member, and an upstream guide part. The photosensitive member is disposed on the conveying path. The upstream guide part is disposed upstream of the pair of registration rollers on the conveying path to guide the recording sheet toward the pair of registration rollers in cooperation with the conveying path. The upstream guide part is formed with a concaved part that is concaved in a direction away from the conveying path.