Sheet Feeding Device Segmented Roller Ejection Control

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Solution Overview

Problem

Conventional sheet feeding devices often fail to eject sheets properly, leading to damage and paper jams due to the preceding sheet's rear end not being fully ejected before the next sheet is fed, especially in cases where the device has to wait for memory write operations during printing, causing the sheets to stick together.

Innovation Solution

The sheet feeding device temporarily stops the preceding sheet at a registration position and resumes feeding after the following sheet reaches the registration position from a separable roller pair, ensuring the preceding sheet is fully ejected before the next sheet is fed, thereby preventing sticking and paper jams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the sheet feeding device temporarily stops feeding the sheet at the registration position to wait for memory write operations, then the image reading can be completed accurately, but the preceding sheet may not be fully ejected before the next sheet is fed, causing sheets to stick together and fail to eject properly

Engineering Contradiction:

Improveimage reading accuracyVSAvoidsheet ejection reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The roller pairs are divided into two functional groups: non-separable roller pairs (pre-reading roller pair, post-reading roller pair) that maintain continuous contact for reliable sheet transport, and separable roller pairs (feeding roller pair, ejection roller pair) that can be separated to clear the sheet path. This segmentation allows the system to maintain reading accuracy while preventing ejection failures by enabling complete sheet clearance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The roller pairs are made dynamically controllable - the separable roller pairs can be separated from each other under control. During the temporary stop for memory write operations, the separable roller pairs can be separated to ensure the preceding sheet is fully ejected, then resumed for feeding the next sheet. This dynamic adjustment resolves the contradiction between maintaining reading accuracy and ensuring reliable ejection.

Inventive Principle:

Principle #15Dynamics

2Productivity

If the device feeds sheets continuously without stopping, then productivity is maintained, but sheets may jam or stick together when memory write operations require waiting

Engineering Contradiction:

Improvesheet feeding speedVSAvoidsheet ejection reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The separable roller pairs enable dynamic control of the sheet feeding process. When a temporary stop is required for memory write operations, the system can separate the roller pairs to clear the sheet path, preventing jams while maintaining productivity by quickly resuming operation after the stop.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

By segmenting the roller pairs into separable and non-separable groups, the system can selectively control which rollers remain engaged during stops. The non-separable roller pairs maintain sheet transport, while separable roller pairs can be disengaged to prevent stacking and ensure complete ejection, thus maintaining productivity without sacrificing reliability.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If the preceding sheet is not fully ejected before feeding the next sheet, then device complexity is reduced, but sheet damage occurs due to improper ejection and paper jams

Engineering Contradiction:

Improveejection control mechanismVSAvoidsheet damage

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The roller pairs are segmented into separable and non-separable groups, providing a relatively simple mechanism to ensure complete sheet ejection. The separable roller pairs can be separated to clear the sheet path, preventing the next sheet from interfering with the ejection of the preceding sheet, thus avoiding sheet damage without requiring complex control systems.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs preliminary separation of the roller pairs before feeding the next sheet, ensuring the preceding sheet is fully ejected. This preliminary action prevents sheet damage by eliminating the risk of interference between consecutive sheets, while keeping the device complexity low through a straightforward separable roller mechanism.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11530103B2Sheet feeding device, image reading device, and image forming apparatus

Publication Date: 2022.12.20 RICOH CO LTD

AI summary

A sheet feeding device includes a roller pair being mutually non-separable; and a roller pair being mutually separable. The sheet feeding device temporarily stops a sheet in a registration position of the non-separable roller pair and then resumes feeding the sheet. The sheet feeding device feeds sheets such that a following sheet reaches the registration position from the separable roller pair after completion of ejection of a preceding sheet.