Secondary Transfer Voltage Control for White-Void-Free Image Forming
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Solution Overview
Problem
Conventional image forming apparatuses face issues with 'white voids' due to reversed toner charge polarity and image density loss when adjusting secondary transfer voltage, often settling for low voltage to prevent voids at the cost of density, and fail to compatibly suppress both issues.
Innovation Solution
An image forming apparatus that adjusts transfer voltage based on multiple test toner images under different voltages, using a controller to set the voltage based on density variations in these images, ensuring optimal transfer without voids or density loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the secondary transfer voltage is increased to improve transfer efficiency, then the image density is improved, but white voids occur due to reversed toner charge polarity
Solution Approach 1:
The patent applies dynamics by making the transfer voltage adjustable and adaptive rather than fixed. The controller dynamically selects from multiple predetermined transfer voltage values based on detected image density, allowing the system to optimize transfer voltage in real-time for different recording materials and conditions, thus preventing white voids while maintaining image density.
Solution Approach 2:
The patent implements feedback by detecting the image density of transferred images and using this information to adjust the transfer voltage. The controller monitors image density and selects appropriate transfer voltage values from predetermined options, creating a closed-loop control system that prevents white void occurrence while maintaining optimal image quality.
2Object-affected harmful factors
If the secondary transfer voltage is decreased to prevent white voids, then white void occurrence is suppressed, but image density lowering occurs
Solution Approach 1:
The system dynamically adjusts transfer voltage based on actual image density measurements rather than using a fixed low voltage. By selecting from multiple predetermined voltage values based on detected density, the system prevents white voids while maintaining optimal image density for different recording materials.
Solution Approach 2:
The patent changes the transfer voltage parameter adaptively by selecting from multiple predetermined voltage values based on image density detection. This allows the system to optimize the voltage parameter for different recording materials and conditions, preventing both white voids and image density loss.
3Device complexity
If a fixed transfer voltage is used to simplify the control system, then device complexity is reduced, but adaptability to different recording materials deteriorates
Solution Approach 1:
The system achieves adaptability without excessive complexity by implementing dynamic voltage selection from a limited set of predetermined values. The controller adjusts transfer voltage based on detected image density and recording material type, providing versatility while maintaining manageable system complexity through discrete voltage options rather than continuous adjustment.
Solution Approach 2:
The patent enables adaptability to different recording materials by changing the transfer voltage parameter based on detected conditions. The system selects from multiple predetermined voltage values to optimize transfer for different paper types and conditions, achieving versatility without requiring complex continuous control mechanisms.
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 apparatus effectively suppresses 'white voids' and maintains image density by dynamically adjusting transfer voltage through a controller-driven process using test toner images, optimizing transfer conditions.
Implementation Method 1
The transfer of the toner image from an image bearing member to the recording material is performed by applying a transfer voltage to a transfer member such as a transfer roller which contacts the image bearing member to form a transfer portion (transfer nip)
Implementation Method 2
an acquiring portion configured to acquire information on an image density of an image transferred on the recording material
Data Source
AI summary
An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, a power source, an acquiring portion, and a controller capable of executing an operation in an adjustment mode. A plurality of test toner images transferred onto a recording material in the occurrence in the adjusting mode include a first test toner image transferred under application of a first test voltage and a second test toner image transferred under application of a second test voltage different from the first test voltage. In the operation in the adjustment mode, the controller adjusts the transfer voltage set for transfer on the basis of first information on variation in image density acquired in different regions of the first test toner image and second information on variation in image density acquired in different regions of the second test toner image.