Grounded Registration Roller and Guide Mechanism for Image Transfer Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face challenges in ensuring stable electrostatic latent image and toner image transfer due to sheet conveyance issues, leading to potential defects like banding and image shifts, which are not adequately addressed by existing registration and guiding systems.
Innovation Solution
The apparatus incorporates a housing with a grounded metal inner wall, a registration roller pair with a metallic and elastic roller, and conductive guiding portions, along with a resistor-based grounding conductive mechanism to ensure electrical conductivity and stable sheet conveyance, preventing electrostatic instability and image defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional registration roller pairs and guide members are used, then sheet conveyance is achieved, but electrostatic instability occurs leading to image defects
Solution Approach 1:
The patent applies equipotentiality by electrically grounding the registration roller, guide members, and housing through conductive connections. This creates an equipotential environment that prevents electrostatic charge accumulation on the sheet, thereby eliminating image defects such as banding and white spots while maintaining reliable toner transfer.
Solution Approach 2:
The patent introduces conductive guide members and grounding mechanisms as intermediaries between the sheet and the housing. These intermediaries provide a controlled electrical path that dissipates static charges, preventing harmful electrostatic effects during sheet conveyance and transfer without interfering with the mechanical conveyance function.
2Object-affected harmful factors
If metal housing with grounded inner wall is used, then electrostatic stability is improved, but device complexity increases
Solution Approach 1:
The patent merges the grounding function with existing structural components by making the housing itself conductive and grounding it. The registration roller, guide members, and housing are integrated into a unified grounding system, eliminating the need for separate grounding mechanisms and reducing overall device complexity while maintaining electrostatic control.
Solution Approach 2:
The conductive housing serves multiple functions: it provides structural support, acts as an electrostatic shield, and serves as a grounding reference. The guide members simultaneously guide sheet conveyance and dissipate static charges. This multi-functionality reduces the number of dedicated components needed for electrostatic control.
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 transfer of toner images by grounding key components and ensuring consistent sheet conveyance, thereby reducing image defects and maintaining image quality.
Implementation Method 1
The grounding conductive mechanism electrically conducts the registration roller, the first guiding portion, and the second guiding portion to the inner wall via the resistor.
Implementation Method 2
This configuration stabilizes the transfer of toner images by grounding key components and ensuring consistent sheet conveyance, thereby reducing image defects and maintaining image quality.
Data Source
AI summary
An image forming apparatus includes a housing, a registration roller pair, a first guiding portion, a second guiding portion, a resistor, and a grounding conductive mechanism. The housing is made of metal and has a grounded inner wall. The registration roller pair is located between the paper sheet feeder and the transfer member in the sheet conveyance path, includes a metallic registration roller and a facing roller that is constituted of an elastic material, and rotates in abutting contact with the registration roller, so as to convey the sheet toward the transfer nip portion. The first guiding portion is made of metal. The second guiding portion is made of a conductive resin material. The grounding conductive mechanism electrically conducts the registration roller, the first guiding portion, and the second guiding portion to the inner wall via a resistor.