Image Forming Apparatus Cleaning Toner Control
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Solution Overview
Problem
Existing image forming apparatuses face challenges in maintaining the optimal amount of toner on the image bearing element during cleaning, leading to either excessive or insufficient toner supply, which affects image quality due to varying print coverage in preceding processes.
Innovation Solution
An image forming apparatus that includes a control portion to calculate the average print coverage over a predetermined period, determining the appropriate amount of cleaning toner to be supplied to the image bearing element, ensuring the toner is neither excessive nor insufficient by forming a cleaning toner image and adjusting the transfer voltage polarity to manage toner distribution effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the amount of cleaning toner is adjusted only according to the print coverage in the immediately preceding image forming process, then the cleaning toner supply can be optimized for that specific process, but the accumulated residual toner from multiple processes causes the toner amount to become excessive or insufficient
Solution Approach 1:
The system performs preliminary calculation of the average print coverage over a predetermined period before the cleaning process. This advance preparation allows the control portion to determine the appropriate cleaning toner amount based on historical data, ensuring that the cleaning toner is supplied in the optimal amount without excess or insufficiency, thereby resolving the contradiction between precision and reliability.
Solution Approach 2:
The system uses feedback from the print coverage calculation portion, which continuously monitors and stores the print coverage of sheets over a predetermined period. The control portion refers to this stored historical data to determine the cleaning toner amount, creating a closed-loop control system that adapts to actual usage patterns and ensures accurate cleaning toner supply.
2Productivity
If the surface of the image bearing element contacts the cleaning element when toner is low, then cleaning can proceed, but friction increases and damages the surface of the image bearing element
Solution Approach 1:
The control portion forms a cleaning toner image in advance before the cleaning process begins. This preliminary action ensures that a sufficient amount of toner is present on the surface of the image bearing element when cleaning starts, preventing direct contact between the cleaning element and the element surface and thereby avoiding friction-induced damage while maintaining cleaning efficiency.
Solution Approach 2:
By supplying cleaning toner in advance through the formation of a cleaning toner image, the system creates a protective cushion of toner on the image bearing element surface. This beforehand cushioning prevents the harmful friction and surface damage that would otherwise occur during cleaning when toner levels are low.
3Productivity
If the surface of the image bearing element contacts the cleaning element when toner is high, then cleaning can proceed, but toner leaks to the downstream side of the cleaning element
Solution Approach 1:
The control portion uses feedback from the print coverage calculation to precisely determine the optimal cleaning toner amount. By referring to the stored average print coverage data, the system can accurately control the toner supply to match actual usage patterns, preventing toner leakage while maintaining efficient cleaning operation.
Solution Approach 2:
The system dynamically adjusts the cleaning toner amount based on the calculated average print coverage parameter. By changing the toner supply parameter according to historical print coverage data, the system optimizes the balance between preventing surface damage and avoiding toner leakage, thereby resolving the contradiction.
4Manufacturing precision
If cleaning toner is supplied to maintain optimal toner amount, then image quality is maintained, but the cleaning process time increases
Solution Approach 1:
The control portion continuously calculates the average print coverage over a predetermined period and continuously determines the optimal cleaning toner amount. This continuous operation ensures that the cleaning toner is always supplied in the optimal amount, maintaining image quality consistency while avoiding unnecessary delays through efficient, real-time control.
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 solution ensures a consistent and optimal amount of cleaning toner is supplied, preventing toner leakage or excess, thereby maintaining image quality and reducing surface damage, while also shortening the cleaning process by intermittently forming cleaning toner images in the sheet feed direction.
Implementation Method 1
Some electrophotographic image forming apparatuses are configured to transfer a toner image that is born on an image bearing element, such as a photoreceptor drum and an intermediate transfer element, onto a sheet in a transfer position
Implementation Method 2
if the surface of the image bearing element contacts the cleaning element to be cleaned, friction will increase between the surface of the image bearing element and the cleaning element
Implementation Method 3
the control portion makes the image forming portion form a cleaning toner image to be supplied to the image bearing element at time of cleaning by the cleaning element
Data Source
AI summary
An image forming apparatus includes: an image bearing element that bears a toner image to be transferred to a sheet; an image forming portion that forms the toner image on the image bearing element; a cleaning element that cleans the surface of the image bearing element; a storage portion that stores a history of print coverage; a control portion that makes the image forming portion form a cleaning toner image to be supplied to the image bearing element at time of cleaning by the cleaning element; and a print coverage calculating portion that calculates the print coverage of the sheet. The control portion obtains an average value of the print coverage in a period from after a previous cleaning by the cleaning element until before a current cleaning, and determines an amount of toner for the cleaning toner image supplied to the image bearing element based on the average value.