Sheet Feeding Elevator Mechanism for Contamination Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sheet feeding devices in image forming apparatuses face issues with high-speed continuous feeding of sheets with high surface smoothness, leading to surface contamination, damage, and wrinkle generation due to prolonged contact with the pickup roller, especially in humid environments.
Innovation Solution
A sheet feeding device with an elevator mechanism that displaces a sheet carrying plate between a sheet feeding position and a separating position, controlled by a controller to minimize contact time with the pickup roller, combined with warm air mechanisms to prevent moisture absorption issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pickup roller remains in contact with the sheets for high-speed continuous feeding, then sheet feeding speed is improved, but the sheet surface becomes contaminated and damaged
Solution Approach 1:
The sheet carrying plate is made movable between a feeding position (where sheets contact the pickup roller) and a separated position (where sheets are elevated away from the roller). This dynamic positioning allows the system to switch between high-speed feeding mode and protection mode, resolving the contradiction between feeding speed and sheet surface protection
Solution Approach 2:
The sheet carrying plate alternates between the feeding position and separated position in a periodic cycle. During feeding operations, the plate is at the feeding position enabling high-speed operation; between feeds, it moves to the separated position to prevent contamination. This periodic action allows the system to achieve both high productivity and sheet surface protection
2Manufacturing precision
If sheets with high surface smoothness are used for improved printing quality, then printing suitability is improved, but sheets easily absorb moisture and generate wrinkles
Solution Approach 1:
The movable sheet carrying plate dynamically adjusts the contact time between sheets and the pickup roller. By minimizing contact time through rapid positioning between feeding and separated positions, the system reduces moisture transfer from the roller to high-smoothness sheets, preventing wrinkle generation while maintaining printing quality
Solution Approach 2:
The system rushes through the feeding operation quickly by using the elevator mechanism to rapidly position sheets at the feeding location, complete the feed, then immediately move to the separated position. This rushing through minimizes the duration of harmful contact between the roller and moisture-sensitive high-smoothness sheets
Data Source
AI summary
A sheet feeding device has: a sheet accommodating portion that accommodates a sheet stack of a plurality of sheets; a sheet carrying plate that is provided within the sheet accommodating portion and stacks the sheet stack thereon; a pickup roller that contacts an upper face of the sheet stack and dispatches a sheet on an uppermost layer of the sheet stack, an elevator mechanism that displaces the sheet carrying plate between a sheet feeding position in which the upper face of the sheet stack contacts the pickup roller, and a separating position in which the upper face of the sheet stack separates from the pickup roller by a predetermined distance; and a controller that controls an operation of the elevator mechanism such that the sheet carrying plate is lowered to the separating position after a sheet feeding operation for feeding a sheet at the sheet feeding position is completed.