Transfer Roller Guide Member Trailing Edge Support
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Solution Overview
Problem
In electro-photographic image forming apparatuses, the rapid separation of sheets from the image carrier at the trailing edge leads to image disturbance due to electric discharge, which existing guide plates fail to adequately address.
Innovation Solution
A transfer apparatus comprising a flexible guide member and an inflexible protrusion supporting member, where the guide member guides the sheet towards the transfer roller, and the protrusion supporting member rigidly supports the trailing edge after it passes the guide member, preventing rapid separation from the image carrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a guide plate is provided to guide the sheet to the image carrier side at the upstream of the transferring portion, then the sheet can be guided to the transferring portion, but the trailing edge of the sheet rapidly separates from the image carrier immediately after passing the guide plate, causing image disturbance
Solution Approach 1:
The guide structure is divided into two functional segments: a flexible guide member for guiding the sheet to the transferring portion, and an inflexible protrusion supporting member for supporting the trailing edge. This segmentation allows each part to perform its specific function optimally without interfering with the other, resolving the contradiction between sheet guidance and image quality maintenance.
Solution Approach 2:
Different parts of the guide structure have different mechanical properties: the guide member is flexible to accommodate sheet curvature and guidance needs, while the protrusion supporting member is inflexible to provide rigid support to the trailing edge. This local differentiation of material properties allows the system to simultaneously achieve proper sheet guidance and prevent trailing edge separation that causes image disturbance.
2Reliability
If the guide plate is made rigid to provide stable support, then the sheet can be reliably guided, but the trailing edge separation is not prevented, causing developer scattering
Solution Approach 1:
The guide structure is segmented into a flexible guide member for stable sheet guidance and an inflexible protrusion supporting member for preventing trailing edge separation. Each segment is optimized for its specific function, with the flexible member providing reliable guidance while the inflexible protrusion preventing developer scattering by maintaining sheet contact with the image carrier.
Solution Approach 2:
The protrusion supporting member acts as an intermediary element between the guide member and the trailing edge of the sheet. It receives the sheet from the flexible guide member and provides rigid support to prevent separation, thereby mediating the transition from guidance to support function and preventing developer scattering.
3Manufacturing precision
If the guide member is made inflexible to provide rigid support, then the trailing edge can be supported, but the sheet cannot be properly guided to the transferring portion
Solution Approach 1:
The guide structure is divided into a flexible guide member for sheet guidance and an inflexible protrusion supporting member for trailing edge support. This segmentation allows the flexible member to properly guide the sheet to the transferring portion while the inflexible protrusion provides the necessary rigid support to the trailing edge, resolving the contradiction between guidance and support functions.
Solution Approach 2:
The guide member is made flexible locally to accommodate sheet curvature and provide proper guidance to the transferring portion, while the protrusion supporting member is made inflexible locally to provide rigid support to the trailing edge. This local differentiation of mechanical properties allows both guidance and support functions to be performed effectively without compromise.
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 configuration effectively suppresses image disturbance near the trailing edge by ensuring the trailing edge is reliably supported, preventing the scattering of developer and maintaining image quality.
Implementation Method 1
a transfer roller applied with a transfer bias for electrostatically attracting the developer image from the image carrier
Implementation Method 2
a flexible guide member which has a thin plate shape as seen in a side sectional view, and is attached to the guide-member supporting frame at an upstream of the transferring portion in the conveyance path to guide the record medium to the transferring portion
Data Source
AI summary
A transfer apparatus includes a transfer roller which transfers developer on an image carrier onto a recording medium conveyed along a conveyance path, a supporting frame which is provided at an upstream of a transferring portion where the image carrier and the transfer roller are closest, in the conveyance path, and is provided at a side of the transfer roller with respect to the conveyance path, a flexible guide member which has a thin plate shape, and is attached to the supporting frame at an upstream of the transferring portion in the conveyance path to guide the record medium to the transferring portion, and a inflexible protrusion supporting member which is provided on the supporting frame between the transferring portion and the guide member in the conveyance path, and which protrudes toward the conveyance path to support a trailing edge of the record medium after passing the guide member.