Conductive Intermediate Transfer Belt for Primary Transfer
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Solution Overview
Problem
Conventional image forming apparatuses require multiple voltage power supplies for primary transfer, increasing size and cost, and requiring time to set suitable transfer voltages due to resistance variations, which complicates the image formation process.
Innovation Solution
An image forming apparatus with a conductive intermediate transfer belt that allows current to flow in the rotational direction from a current supply member to image bearing members, eliminating the need for multiple voltage power supplies by using a single current supply member for primary transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple voltage power supplies are used for primary transfer in each image forming unit, then suitable primary transfer voltage can be set for each unit, but the number of power supplies increases, increasing apparatus size and cost
Solution Approach 1:
The patent merges the primary transfer function into the intermediate transfer belt by making the belt itself conductive. Instead of having separate voltage power supplies for each primary transfer roller, a single voltage power supply is used to apply voltage to the intermediate transfer belt, which then serves all image forming units. This reduces the number of power supplies from multiple (one per image forming unit) to just one, thereby reducing apparatus size and cost while maintaining reliable primary transfer performance across all units.
2Reliability
If primary transfer voltage is calculated before image formation considering resistance variation, then suitable transfer voltage is set, but time is consumed before image formation can start
Solution Approach 1:
The patent applies preliminary action by pre-applying a constant voltage to the intermediate transfer belt before image formation begins. The single voltage power supply continuously maintains the intermediate transfer belt at the appropriate potential, so that when image formation is initiated, the primary transfer function is already ready to operate. This eliminates the need for time-consuming resistance measurements and voltage calculations before each image formation process, as the voltage is already established and maintained continuously.
3Device complexity
If a single current supply member is used for primary transfer, then the number of power supplies is reduced, but the intermediate transfer belt must be made conductive
Solution Approach 1:
The patent changes the electrical parameter of the intermediate transfer belt by incorporating conductive materials into the belt structure. The intermediate transfer belt is manufactured with carbon black or other conductive fillers mixed into the resin, giving it sufficient electrical conductivity to carry the primary transfer function. This parameter change allows the belt to function as an active electrical component rather than a passive mechanical component, enabling the use of a single power supply while maintaining ease of manufacture through standard material mixing and extrusion processes.
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 reduces the number of power supplies needed, decreases the apparatus's size and cost, and enables faster setup for image formation by stabilizing primary transfer performance across varying resistance conditions.
Implementation Method 1
the intermediate transfer belt is provided with electrical conductivity capable of passing a current from a contact position of the current supply member in the rotational direction of the intermediate transfer belt to the plurality of image bearing members via the intermediate transfer belt
Implementation Method 2
the power supply applies a voltage to the current supply member to pass a current from the current supply member to the plurality of image bearing members via the intermediate transfer belt
Data Source
AI summary
An image forming apparatus sequentially transfers toner images formed on a plurality of photosensitive drums onto an intermediate transfer member or a transfer material to form an image. The image forming apparatus includes an intermediate transfer belt provided with electrical conductivity, and a power supply for applying a voltage to a current supply member contacting the outer circumferential surface of the intermediate transfer belt to pass a current from the current supply member to the plurality of photosensitive drums via the intermediate transfer belt, thus primarily transferring the toner images from the plurality of photosensitive drums onto the intermediate transfer belt.