Developing Roller Speed Control for Toner Sticking Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-magnetic one-component development type image forming apparatuses, toner sticking to the regulation blade due to frictional heat leads to image defects like white streaks, especially during endurance printing, as external additives deteriorate over time, increasing the likelihood of toner sticking in the latter half of the device's life.
Innovation Solution
Implementing a speed reduction control mechanism that lowers the rotation speed of the developing roller during warming-up and intermittent printing, and when ambient temperatures are high or printing intervals are long, to reduce friction and prevent toner sticking, while maintaining image quality and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the developing roller rotates at high speed during warming-up, then the warming-up time is reduced, but frictional heat increases causing toner to melt and stick to the regulation blade
Solution Approach 1:
The patent applies dynamics by making the rotation speed of the developing roller variable rather than constant. The control section adjusts the rotation speed based on operational phase (warming-up vs. normal operation) and environmental conditions (temperature, printing intervals), allowing the system to optimize between warming-up efficiency and toner sticking prevention at different times
Solution Approach 2:
The patent changes the parameter of rotation speed dynamically. During warming-up, the rotation speed is set to a first reduced speed to limit frictional heat. When toner sticking risk is detected (high temperature or long printing intervals), the rotation speed is further reduced to a second reduced speed. This parameter adjustment directly controls the balance between warming efficiency and toner adhesion prevention
2Reliability
If external additives are used in toner to prevent sticking, then toner fluidity and chargeability improve, but additives embed or detach during endurance printing causing toner deterioration
Solution Approach 1:
The patent applies preliminary anti-action by proactively reducing the rotation speed of the developing roller during warming-up and under high-risk conditions (high temperature, long printing intervals). This preventive measure counteracts the frictional heat generation before it can cause toner melting and sticking, addressing the root cause rather than relying solely on external additives
Solution Approach 2:
The patent replaces the chemical approach (relying on external additives in toner) with a mechanical control approach (controlling rotation speed). Instead of depending on additives to prevent sticking, the system uses speed control to reduce frictional heat generation at the source, thereby extending toner life without compromising sticking prevention
3Object-affected harmful factors
If the developing roller speed is reduced to prevent toner sticking, then frictional heat is reduced, but image formation efficiency decreases
Solution Approach 1:
The patent applies periodic action by implementing different rotation speed regimes at different times. During warming-up phase, the first reduced speed is used. During normal operation, the normal speed is restored for efficiency. When specific conditions arise (high temperature or long printing intervals exceeding a threshold), the second reduced speed is applied temporarily. This periodic adjustment maintains productivity while preventing toner sticking
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 toner sticking and white streaks, prolonging the device's life and maintaining image quality by optimizing the speed reduction control based on printing conditions and ambient temperatures, thereby enhancing the overall performance and longevity of the image forming apparatus.
Implementation Method 1
a temperature detecting device that detects a temperature in a vicinity of the developing device
Implementation Method 2
a toner might melt due to frictional heat generated between the regulation blade and the rotating developing roller
Implementation Method 3
The charging device charges the image carrying member to a prescribed surface potential
Implementation Method 4
The exposure device exposes to light the surface of the image carrying member charged by the charging device so as to form thereon an electrostatic latent image with attenuated electrostatic charge
Implementation Method 5
when the toner passes below the regulation blade, the surface of the developing roller and the toner become charged by friction therebetween
Data Source
AI summary
An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a control section, and a temperature detecting device. The developing device includes a developer carrying member having an outer circumferential surface on which a toner layer is formed, and a regulation blade that regulates a thickness of the toner layer. The control section executes speed reduction control to reduce a rotation speed of the developer carrying member at a time of warming-up. When a printing operation to be performed after the warming-up is intermittent printing and an interval of the intermittent printing is not less than a prescribed time or a temperature detected by the temperature detecting device is not more than a prescribed temperature, the control section reduces the rotation speed of the developer carrying member in the speed reduction control to a second speed lower than the first speed.