Transfer Device Prepressing Member for Toner Scattering Control
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Solution Overview
Problem
High-speed image forming apparatuses experience toner image scattering due to compressed air between the intermediate transfer belt and the recording sheet, leading to defects in high-density images, particularly straight lines, as the existing solutions either partially suppress scattering or introduce gap discharge issues.
Innovation Solution
A transfer device with a prepressing member positioned upstream of the contact section between the intermediate transfer belt and the recording sheet, applying a pressure that is higher than the contact pressure between the second transfer roller and the backup roller, to manage the fluid force and electrostatic forces, ensuring the sum of forces exceeds the fluid force and prevents scattering, while maintaining a controlled distance to avoid gap discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure applied by the prepressing member is increased to suppress toner image scattering, then scattering suppression is improved, but gap discharge may occur
Solution Approach 1:
The patent optimizes the pressure parameter applied by the prepressing member to a specific range (0.5 to 5 N/mm) that balances scattering suppression and gap discharge prevention. This parameter optimization resolves the contradiction by finding the optimal operating point where sufficient pressing force prevents toner scattering while avoiding excessive force that would cause gap discharge.
Solution Approach 2:
The prepressing member acts as an intermediary component between the intermediate transfer belt and the recording sheet. It applies controlled pressure to the toner image before the main transfer process, managing the fluid force and electrostatic forces to prevent scattering without creating excessive pressure gaps that would lead to discharge.
2Object-affected harmful factors
If the pressure applied by the prepressing member is decreased to prevent gap discharge, then gap discharge is suppressed, but toner image scattering increases
Solution Approach 1:
The patent establishes a minimum pressure threshold (0.5 N/mm) for the prepressing member that is sufficient to suppress toner image scattering while preventing gap discharge. This parameter setting resolves the contradiction by ensuring the pressure is high enough for scattering suppression but not so high as to cause gap discharge.
3Productivity
If high-speed transfer is used to improve productivity, then productivity is improved, but toner image scattering increases
Solution Approach 1:
The prepressing member applies pressure to the toner image before the main transfer process begins, in advance of the high-speed transfer operation. This preliminary action prepares the toner image by securing it to the intermediate transfer belt, ensuring that even during high-speed transfer, the toner remains firmly attached and does not scatter.
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
Effectively suppresses toner image scattering and prevents gap discharge, ensuring high-quality image formation by balancing forces to securely transfer images without defects, even at high speeds.
Implementation Method 1
manage the fluid force and electrostatic forces, ensuring the sum of forces exceeds the fluid force and prevents scattering
Implementation Method 2
manage the fluid force and electrostatic forces, ensuring the sum of forces exceeds the fluid force and prevents scattering
Implementation Method 3
A pressure applied by the prepressing member is lower than a pressure with which the facing member is in pressed contact with the transfer member
Data Source
AI summary
A transfer device includes a transfer device, a facing member, and a prepressing member. The transfer member transfers a toner image, which is carried on an intermediate transfer member, to a recording medium. The facing member is disposed so as to be in pressed contact with the transfer member with the intermediate transfer member therebetween. The prepressing member is disposed so as to be in pressed contact with the transfer member with the intermediate transfer member therebetween at a position that is upstream of a contact section in which the facing member is in pressed contact with the transfer member and that is immediately behind a position at which the toner image starts to come into contact with the recording medium. A pressure applied by the prepressing member is lower than a pressure with which the facing member is in pressed contact with the transfer member.