Charging Roller Foam Elastic Layer Tension Control
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Solution Overview
Problem
Existing image forming apparatuses face challenges in achieving stable and uniform electrostatic charging of photoconductor drums due to variations in contact area and pressure, leading to non-uniform charging performance.
Innovation Solution
The use of a charging roller with an elastic layer made of foam material and a non-bonded surface layer, where the surface layer is supported in a non-bonded state and rotates with the elastic layer, and a contact member applies tension to the surface layer, ensuring a uniform contact area and stable charging performance by maintaining the elastic layer's deformation and surface smoothness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a charging roller with foam material elastic layer is used, then charging uniformity is improved, but contact area stability deteriorates
Solution Approach 1:
The patent applies this principle by using a thin film surface layer (0.01-0.1mm thick) covering the foam elastic layer. The thin film provides a stable contact surface that maintains consistent contact area with the photoconductor, while the underlying foam layer continues to provide elastic deformation for uniform pressure distribution. This combination resolves the contradiction by separating the functions: thin film for contact stability, foam for charging uniformity.
Solution Approach 2:
The patent uses a composite structure combining foam material (providing elasticity and deformation) with a surface layer (providing stable contact). This composite design allows the foam to deform elastically for uniform pressure while the surface layer maintains stable geometric contact area, thus resolving the contradiction between charging uniformity and contact area stability.
2Strength
If the surface layer is bonded to the elastic layer, then structural integrity is improved, but charging performance stability deteriorates
Solution Approach 1:
The patent applies this principle by extracting the bonding function and replacing it with a non-bonded support structure. The surface layer is supported by the elastic layer through mechanical support rather than chemical bonding, allowing independent movement and deformation of each layer. This prevents the bonding-induced stress and deformation that would compromise charging performance stability.
Solution Approach 2:
The patent makes the surface layer dynamic by not bonding it to the elastic layer. The surface layer can independently deform and adapt to the elastic layer's movement, allowing the system to dynamically adjust to variations in the photoconductor surface. This dynamic configuration maintains charging performance stability while still providing structural support.
3Manufacturing precision
If contact pressure is increased to improve charging uniformity, then charging performance is improved, but device complexity increases
Solution Approach 1:
The patent applies this principle by designing a system where the foam elastic layer automatically adjusts contact pressure through its inherent elastic properties. When the charging roller contacts the photoconductor, the foam deforms elastically to distribute pressure uniformly across the contact area without requiring external pressure control mechanisms. This self-regulating elastic deformation achieves charging uniformity while avoiding complex pressure control systems.
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 stabilizes the charging performance by maintaining a consistent contact area and pressure, reducing fluctuations in charging regions and achieving uniform electrostatic charging, thereby improving the overall charging efficiency and reducing manufacturing costs.
Implementation Method 1
The elastic layer is disposed facing the image bearing member, is supported in a rotatable manner about a rotation axis, and is composed of a foam material
Implementation Method 2
The applying member applies voltage to an image bearing member
Implementation Method 3
The contact member comes into contact with the surface layer at an upstream side, in a rotational direction of the applying member, relative to an imaginary line segment that connects a rotation axis of the image bearing member and the rotation axis of the applying member, so as to apply tension to the surface layer
Data Source
AI summary
An applying device includes an applying member and a contact member. The applying member applies voltage to an image bearing member and has an elastic layer and an endless surface layer. The elastic layer is disposed facing the image bearing member, is rotatable about a rotation axis, and is composed of a foam material. The surface layer surrounds an outer periphery of the elastic layer, is supported by the elastic layer in a non-bonded state, and is rotatable together therewith. The contact member comes into contact with the surface layer at an upstream side, in a rotational direction of the applying member, relative to an imaginary line segment connecting a rotation axis of the image bearing member and the rotation axis of the applying member, so as to apply tension to the surface layer at a contact position between the image bearing member and the applying member.