Transfer Voltage Control for Charge Member Smearing Prevention
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Solution Overview
Problem
Conventional image forming apparatuses using the electrophotographic method face issues with smearing of the charge member, particularly when forming images with low page coverage, leading to charging defects and image defects due to the optimization of transfer voltage focusing solely on transfer properties.
Innovation Solution
An image forming apparatus that includes a detection unit to monitor the toner amount, a memory unit to adjust variables based on detected toner amounts, and a control unit to adjust the transfer voltage accordingly, increasing the voltage for high toner amounts and decreasing it for low toner amounts to prevent smearing while maintaining transfer properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transfer voltage is increased to improve transfer properties, then the transfer efficiency is improved, but the smearing of the charge member worsens
Solution Approach 1:
The patent applies dynamics by making the transfer voltage adjustable rather than fixed. The control unit dynamically changes the transfer voltage based on detected smearing conditions, allowing the system to adapt to varying operational states and prevent charge member smearing while maintaining adequate transfer efficiency
Solution Approach 2:
The patent implements feedback by using a detection unit to monitor charge member conditions (smearing) and feeding this information back to the control unit, which then adjusts the transfer voltage accordingly. This closed-loop control prevents smearing by responding to actual device state rather than using a fixed voltage
2Object-generated harmful factors
If the transfer voltage is decreased to suppress charge member smearing, then the smearing is reduced, but the transfer properties deteriorate
Solution Approach 1:
The system dynamically adjusts the transfer voltage based on real-time detection of charge member conditions. When smearing is detected, the voltage is decreased to suppress smearing; when smearing is suppressed, the voltage can be increased to maintain transfer efficiency, creating a dynamic balance between the two competing requirements
Solution Approach 2:
The patent changes the transfer voltage parameter in response to detected conditions. By adjusting this critical parameter based on feedback from the detection unit, the system optimizes the balance between preventing charge member smearing and maintaining adequate transfer properties
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
The solution effectively suppresses smearing of the charge member while maintaining transfer properties, ensuring stable image output by dynamically adjusting the transfer voltage based on toner amounts, thereby preventing charging defects and improving image quality.
Implementation Method 1
The process for charging the photosensitive member is performed, for example, by applying a charging bias voltage (hereunder, referred to as 'charging voltage') to a charge member that is disposed in contact with the photosensitive member
Implementation Method 2
the transfer of a toner image from an image bearing member to a transferred member such as a transfer material or an intermediate transfer member is performed, for example, by applying a transfer bias voltage (hereunder, referred to as 'transfer voltage') to a transfer member
Data Source
AI summary
The image forming apparatus includes an image bearing member, a charge member, a transfer unit, an application unit, a cleaning member, a detection unit that detects an index value, and a control unit that, in a case where one or a plurality of consecutive toner images for which the index value is equal to or greater than a first threshold value is formed, performs control which increases an absolute value of the transfer voltage for a toner image to be formed next, and in a case where one or a plurality of consecutive toner images for which the index value is less than a second threshold value equal to or greater than the first threshold value is formed, performs control which decreases an absolute value of the transfer voltage for a toner image to be formed next.