Image Forming Apparatus Flapper Mechanism for Cover-Open Ejection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing image forming apparatuses face the challenge of imposing an undesirable load on the conveyor roller when the rear cover is open, as external objects can contact the exposed rotating roller, potentially causing damage or disruption in the sheet ejection process.

Innovation Solution

The apparatus incorporates a flapper mechanism controlled by an actuator and a biasing member, which guides sheets into specific paths based on the rear cover's position, ensuring the conveyor roller remains stationary when the cover is open, thus preventing external contact and load imposition. The controller coordinates the flapper's movement to ensure reliable sheet ejection onto the rear cover without rotating the conveyor roller.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the rear cover is opened to allow sheet ejection, then the sheet ejection function is improved, but the conveyor roller becomes exposed and vulnerable to external contact and damage

Engineering Contradiction:

Improvesheet ejectionVSAvoidconveyor roller protection

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The flapper is moved to the second position in advance before sheet ejection occurs, creating a protective configuration that prevents external objects from contacting the conveyor roller while still allowing sheets to be ejected onto the open rear cover

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The flapper acts as an intermediary element between the conveyor roller and external objects. When positioned at the second position, it shields the conveyor roller from direct exposure to external contact while maintaining the sheet ejection pathway

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the conveyor roller rotates during sheet ejection onto the rear cover, then the sheet conveyance speed is improved, but external objects may contact the rotating roller and impose undesirable load

Engineering Contradiction:

Improvesheet conveyance speedVSAvoidexternal contact load

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The flapper is positioned at the second position in advance before sheet ejection, creating a protective barrier that prevents external objects from contacting the conveyor roller during rotation, thereby eliminating the harmful load factor while maintaining operational productivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The configuration converts the potentially harmful situation of an exposed rotating roller into a beneficial protected state, where the flapper in the second position uses the roller's rotation for sheet conveyance while simultaneously shielding it from external contact that would cause damage

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS11548749B2Image forming apparatus

Publication Date: 2023.01.10 BROTHER KOGYO KK

AI summary

In an image forming apparatus, a sheet is guided into a first conveyor path or a second conveyor path selectively when a first cover is in a closed position, and is ejected onto the first cover when the first cover is in an open position. Upon power-up, a controller causes a first conveyor roller to rotate but if the first cover is in the open position, when a sheet sensor detects a sheet, the controller does not cause a second conveyor roller to rotate, and causes a flapper to swing from a first position to a second position, and when a front end of the sheet reaches a position downstream of an upstream end of the flapper in a conveyance direction of the sheet conveyed by the first conveyor roller, the controller causes the flapper to swing from the second position to the first position.