Primary Transfer Brush Rectilinear Upstream End Geometry
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Solution Overview
Problem
The existing image forming apparatus with brush-typed transfer members face issues with uneven contact and potential electric discharges due to random orientation of conductive filaments, leading to degradation of primary transfer properties.
Innovation Solution
The design of a primary transfer brush with a rectilinear upstream end geometry and a specific arrangement of conductive and non-conductive filament bundles ensures stable and uniform contact with the intermediate transfer belt, reducing non-contact areas and enhancing the primary transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a brush-typed transfer member with randomly oriented conductive filaments is used, then contact uniformity is improved, but position stability and transfer consistency deteriorate due to random filament orientation at the upstream end
Solution Approach 1:
The patent applies local quality by differentiating the filament arrangement at the upstream end from the rest of the brush member. Specifically, the upstream end features rectilinearly arranged conductive filaments (improved local quality for position stability), while the downstream portion maintains randomly oriented filaments (preserving contact uniformity benefits). This localized structural differentiation resolves the contradiction between contact uniformity and transfer consistency.
Solution Approach 2:
The patent introduces asymmetry in the filament orientation pattern along the brush member's length. The upstream end has a symmetric rectilinear arrangement, while the downstream portion has asymmetric random orientation. This asymmetric design allows the brush to achieve both stable positioning (through the symmetric upstream end) and uniform contact (through the asymmetric downstream portion), resolving the technical contradiction.
2Reliability
If the upstream end of the brush-typed transfer member is positioned accurately with respect to the contact area, then transfer property is improved, but manufacturing complexity increases due to precise positioning requirements
Solution Approach 1:
The patent applies preliminary action by pre-arranging the conductive filaments in a rectilinear pattern at the upstream end during manufacturing. This pre-arrangement ensures that regardless of the exact mounting position, the brush member will always present a stable, rectilinear filament structure at the critical upstream contact zone. This eliminates the need for complex post-manufacturing positioning adjustments, resolving the contradiction between transfer property and manufacturing ease.
3Power
If conductive filaments are allowed to contact the intermediate transfer belt freely, then primary transfer voltage application is improved, but electric discharge risk increases due to non-contact areas upstream
Solution Approach 1:
The patent applies preliminary anti-action by using the rectilinearly arranged conductive filaments at the upstream end to prevent electric discharge before it can occur. The rectilinear arrangement ensures continuous, stable contact with the intermediate transfer belt at the upstream zone, eliminating non-contact areas that would otherwise lead to electric discharge. This preventive structural design allows free filament contact downstream (for good power application) while blocking discharge risks upstream, resolving the contradiction.
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 consistently provides improved primary transfer properties, reducing image defects such as density unevenness and maintaining efficiency even with variations in component mounting locations.
Implementation Method 1
a primary transfer voltage applied thereto... each and every one of the filaments can independently come into contact with the back surface of the intermediate transfer belt
Implementation Method 2
a method for coming into contact with the belt by tilting the transfer member such that filaments will come into contact with the back surface of the intermediate transfer belt by being inclined downstream
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
The image forming apparatus includes an image bearing member (1) adapted to bear a toner image, a transfer belt (6) configured to be movable, a transfer device (5, 50) placed across the transfer belt from the image bearing member and adapted to transfer the toner image from the image bearing member to the transfer belt, the transfer device including a brush member (5γ) equipped with a plurality of conductive filaments (5ε) to be put into contact with the belt, wherein the plurality of conductive filaments located at an upstream end in a moving direction of the transfer belt is cut along an orthogonal direction intersecting the moving direction of the transfer belt at right angles or the conductive filaments located at an upstream end of the brush member along the moving direction of the transfer belt are bonded together.