Primary Transfer Roller Electrical Connection Design
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Solution Overview
Problem
In tandem-type color-electrophotography image forming apparatuses, the long distance from the point of support to the point of load in the swingable arm of the primary transfer roller support member compromises the strength and stability of the arm, while the use of wire harnesses and coil springs to maintain electrical connection introduces weight and resilience issues that affect contact pressure and leak current shielding.
Innovation Solution
The image forming apparatus employs a contact member, rotary member, biasing member, rotary conductive member, voltage application device, and conductive connector, where the rotary conductive member is connected to the rotary bias terminal and the bias terminal, using a compression spring to maintain electrical connection without affecting the contact pressure, and the bias application bracket is fixed to the rotation fulcrum shaft to secure the position and reduce the number of parts, thus enhancing strength and reducing assembly complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a swingable arm is used to support the primary transfer roller, then the roller can contact or separate from the photoconductive drum, but the long distance from support point to load point degrades the strength of the arm
Solution Approach 1:
The swingable arm is divided into two separate components: a support bracket fixed to the housing and a transfer roller assembly that rotates independently on a rotation fulcrum shaft. This segmentation eliminates the long cantilevered arm structure while maintaining the contact/separation function through rotation of the roller assembly around the fulcrum.
2Reliability
If wire harnesses or coil springs are used to maintain electrical connection during rotation, then electrical connection is maintained, but weight and resilience issues affect contact pressure and leak current shielding
Solution Approach 1:
The electrical connection function is extracted from the rotating assembly and placed in the stationary housing. A conductive connector in the support bracket provides a fixed electrical connection point, eliminating the need for flexible electrical connections that would interfere with rotation and contact pressure stability.
3Ease of manufacture
If the bias application bracket is not fixed to the rotation fulcrum shaft, then assembly is simpler, but the position is not secured and more parts are needed
Solution Approach 1:
The bias application bracket is merged with the rotation fulcrum shaft by fixing it directly to the shaft. This integration reduces the number of separate parts while ensuring stable positioning of the bias terminal relative to the rotating transfer roller assembly.
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 ensures reliable and stable contact pressure of the primary transfer roller against the photoconductive drum while preventing leak current, improving the structural integrity and reducing the complexity and cost of the intermediate transfer device.
Implementation Method 1
a compression spring to maintain electrical connection without affecting the contact pressure
Data Source
AI summary
An image forming apparatus includes a contact member supplied with voltage by a voltage application device, to contact an object; a rotary member rotatable about a rotation fulcrum shaft fixed to an image forming apparatus, to support the contact member; an biasing member to urge the rotary member to press the contact member against the object; a rotary conductive member fixed to the rotary member and connected electrically to the contact member; a main body side conductive member fixed to the rotation fulcrum shaft at the main body side and connected electrically to the voltage application device; and a conductive connector provided along the rotation fulcrum shaft to contact the rotary conductive member in an axial direction to connect electrically the main body side conductive member and the rotary conductive member. A contact of the conductive connector and a contact of the rotary conductive member are unfixed.