Retard Roller Charge Elimination for Sheet Separation Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sheet feeding apparatuses with retard separating systems face issues with sheet separation and feeding stability due to surface charging and friction, leading to defective feeding states and reduced durability of the retard roller, especially when paper powder is generated, causing the retard roller to rotate in the wrong direction and reducing the coefficient of friction.
Innovation Solution
A sheet feeding apparatus with a charge eliminating mechanism, utilizing a conductive guide member and charge eliminating needles, is introduced to eliminate static charges on the retard roller, preventing paper powder deposition and ensuring stable sheet separation and feeding by maintaining the retard roller's friction coefficient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the retard roller is used for sheet separation, then sheet separation function is achieved, but surface charging occurs leading to reduced friction coefficient and unstable operation
Solution Approach 1:
A conductive member is introduced as an intermediary between the retard roller and the surrounding environment. This conductive member provides a discharge path for static electricity accumulated on the retard roller surface, preventing charge buildup that would otherwise reduce friction and cause sheet feeding instability. The conductive member acts as a mediator that safely transfers excess charge to ground without interfering with the primary sheet separation function.
2Productivity
If multiple sheets are conveyed through the separation nip, then productivity increases, but paper powder deposits on the retard roller reducing friction coefficient
Solution Approach 1:
The conductive member serves as an intermediary that continuously dissipates static charge generated during high-speed multi-sheet conveyance. By providing a constant charge discharge path, it prevents the accumulation of paper powder and static electricity on the retard roller surface, maintaining stable friction characteristics even during continuous high-productivity operation.
Solution Approach 2:
The conductive member enables continuous charge dissipation during the entire sheet conveyance process. Rather than allowing charge to accumulate intermittently, the conductive path maintains continuous electrical connection, ensuring that the friction coefficient remains stable throughout continuous multi-sheet feeding operations, thereby sustaining both productivity and reliability.
3Reliability
If the retard roller rotates in opposite direction for separation, then sheet separation is achieved, but defective feeding occurs when friction coefficient decreases
Solution Approach 1:
The conductive member acts as an intermediary that maintains the friction necessary for stable operation. By preventing static charge accumulation on the retard roller surface, it ensures that the friction coefficient remains sufficient to control the roller's reverse rotation, preventing defective feeding while preserving the sheet separation function that relies on opposite-direction rotation.
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
The charge eliminating mechanism effectively reduces static charges on the retard roller, preventing paper powder deposition and ensuring stable sheet separation and feeding, even when multiple sheets are conveyed, thereby preventing defective feeding states and maintaining the apparatus's operational efficiency.
Implementation Method 1
a charge eliminating mechanism which is provided on an upstream side in the sheet feeding direction in the separation nip portion and eliminates charges of the separating roller
Implementation Method 2
a feed roller which feeds out the sheets in a sheet feeding direction; a separating roller which is rotatable in a direction opposite to the sheet feeding direction and separates the sheets one by one by a separation nip portion which is formed between the separating roller and the feed roller
Data Source
AI summary
Sheets fed out of a cassette supporting the sheets by a pickup roller are separated and fed by a sheet separation feeding unit having a feed roller and a separating roller which is rotatable in a direction opposite to a sheet feeding direction. A charge eliminating mechanism for eliminating charges of the separating roller is arranged on the upstream side in the sheet feeding direction in a separation nip portion between the feed roller and the separating roller.