Primary Transfer Voltage Control for Image Forming Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses, changes in the resistance value of the intermediate transfer member due to temperature fluctuations can lead to transfer failures and image deterioration, particularly in double-sided print modes, where the increased sheet resistance after fixing can cause discharge phenomena and productivity losses due to the need to suspend print jobs and re-set transfer voltages.
Innovation Solution
The apparatus includes a characteristic measuring portion to determine current-voltage characteristics of the primary transfer member, storing this information for determining optimal transfer voltages. It applies different transfer voltages based on target current values for the first and second surfaces of a sheet, using constant-voltage control, thereby minimizing transfer failures and maintaining productivity without the need for frequent voltage re-adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If constant-voltage control is applied to the primary transfer member, then the transfer voltage is stable, but transfer failures occur when the resistance value of the intermediate transfer member changes due to temperature
Solution Approach 1:
The patent implements dynamic transfer voltage control by switching between constant-voltage control and constant-current control based on the printing mode. In double-sided printing mode, when the intermediate transfer member's resistance changes due to temperature, the system transitions to constant-current control to maintain reliable toner transfer, thereby resolving the contradiction between voltage stability and transfer reliability.
2Reliability
If print job is suspended to re-set transfer voltage after temperature change, then transfer reliability is improved, but productivity decreases
Solution Approach 1:
The patent performs preliminary actions by measuring the current-voltage characteristics of the intermediate transfer member before temperature changes significantly affect transfer reliability. The system stores this characteristic information and uses it to proactively adjust control parameters, avoiding the need to suspend print jobs for re-measurement and voltage re-setting, thus maintaining both reliability and productivity.
Solution Approach 2:
The patent implements a feedback mechanism where the measured current-voltage characteristics of the intermediate transfer member are continuously monitored and used to adjust the transfer voltage control strategy. This feedback loop enables the system to adapt to temperature changes without suspending operations, resolving the contradiction between reliability and productivity.
3Reliability
If different transfer voltages are applied for first and second surfaces, then transfer failures are suppressed, but device complexity increases
Solution Approach 1:
The patent uses dynamic control strategies that adapt to the printing mode. In single-sided printing, constant-voltage control is used, while in double-sided printing, the system switches to constant-current control with adjusted target current values for the second surface. This dynamic approach manages complexity by using different control modes only when necessary, rather than implementing a complex dual-mode system for all operations.
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 approach effectively suppresses transfer failures in double-sided print modes while maintaining productivity by determining and applying appropriate transfer voltages based on measured characteristics, reducing the impact of temperature changes on image quality and processing efficiency.
Implementation Method 1
a primary transfer member configured to primarily transfer a toner image from an image carrying member to an intermediate transfer member
Implementation Method 2
The characteristic measuring portion measures current-voltage characteristics of the primary transfer member before a toner image for a first surface of a sheet is primarily transferred
Implementation Method 3
The voltage control portion applies the first transfer voltage to the primary transfer member by a constant-voltage method when the toner image for the first surface of the sheet is primarily transferred
Data Source
AI summary
A characteristic measuring portion measures current-voltage characteristics of a primary transfer member before a toner image for a first surface of a sheet is primarily transferred. A characteristic information storage portion stores characteristic information that indicates the current-voltage characteristics. A first transfer voltage determining portion determines a first transfer voltage based on a first target current value and the characteristic information. A second transfer voltage determining portion determines a second transfer voltage based on a second target current value and the characteristic information that was used when the first transfer voltage was determined, the second target current value being smaller than the first target current value. A voltage control portion applies the first and second transfer voltages to the primary transfer member by a constant-voltage method when the toner images for the first and second surfaces of the sheet are primarily transferred, respectively.