Intermediate Transfer Belt Speed Control for Image Forming Apparatus
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Solution Overview
Problem
In image forming apparatuses using the tandem method, controlling the intermediate transfer belt with high accuracy is challenging, especially in monochrome mode, due to variations in the number of photoconductive drums in contact, which leads to reduced load on the belt and instability in rotation, causing color shift and abrasion issues.
Innovation Solution
The apparatus adjusts the moving speed difference between the intermediate transfer belt and photoconductive drums, optimizing the load applied to the belt by varying the speed of the photoconductive drums based on the mode of operation, ensuring the intermediate transfer belt receives a consistent and sufficient load for accurate rotation, even when the number of drums in contact changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the moving speed of photoconductive drums is reduced to apply load to the intermediate transfer belt, then the rotation accuracy of the intermediate transfer belt is improved, but the productivity decreases due to slower image forming speed
Solution Approach 1:
The patent applies dynamics by making the moving speed of photoconductive drums variable rather than fixed. The control unit dynamically adjusts the speed based on the operational mode (full-color or monochrome) to optimize both rotation accuracy and productivity. In full-color mode, the speed is set to create optimal load for rotation accuracy, while in monochrome mode, the speed is adjusted to maintain productivity while still providing sufficient load.
Solution Approach 2:
The patent changes the speed parameter of photoconductive drums based on operational conditions. By varying this parameter according to whether full-color or monochrome mode is active, the system achieves different optimization goals: rotation accuracy in full-color mode and productivity in monochrome mode, resolving the contradiction between these two requirements.
2Device complexity
If the number of photoconductive drums in contact with the intermediate transfer belt is reduced in monochrome mode, then the device complexity is reduced, but the load on the intermediate transfer belt becomes insufficient causing rotation instability
Solution Approach 1:
The patent changes the speed parameter of the single photoconductive drum in monochrome mode to compensate for the reduced number of drums in contact. By increasing the speed difference between the drum and the intermediate transfer belt, sufficient load is generated to maintain rotation stability despite the simplified configuration with fewer drums.
Solution Approach 2:
The control unit preemptively adjusts the speed parameter before monochrome mode operation begins, ensuring that the single photoconductive drum generates adequate load on the intermediate transfer belt. This preliminary adjustment prevents rotation instability from occurring in the first place, rather than attempting to correct it after the fact.
3Productivity
If the moving speed of photoconductive drums is increased to match the intermediate transfer belt in monochrome mode, then the productivity is improved, but the abrasion of photoconductive drums increases due to grazing contact
Solution Approach 1:
The patent optimizes the speed parameter to find the optimal balance between productivity and drum life in monochrome mode. Rather than simply matching the intermediate transfer belt speed, the system sets the photoconductive drum speed to provide sufficient load for rotation stability while minimizing excessive grazing contact that would cause abrasion, thereby extending drum life while maintaining productivity.
Data Source
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AI summary
A first mode to form a toner image of single color where a pressure contact release section T changes a primary transfer section 7 to be in a pressure contact state, and a second mode to form an overlapped toner image where the pressure contact device T changes a plurality of the primary transfer sections 7 to be in the pressure contact state can be executed, wherein a speed difference D1 between an image carrier 1 and an intermediate transfer belt 6 in the first mode is controlled to be greater than a speed difference D2 between the image carrier 1 and the intermediate transfer belt 6 in the second mode.