Developing Roller Voltage Control for Toner Supply Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-magnetic one-component development type image forming apparatuses, insufficient toner supply on the developing roller can lead to afterimages or development ghosts due to the thin toner layer, which affects image quality and coverage, especially during high coverage rate printing.
Innovation Solution
The apparatus includes a developing device with a toner supply system that adjusts the supply voltage and development voltage dynamically based on cumulative print cycles, ensuring a consistent toner supply and maintaining optimal toner layer thickness through a regulation blade, thereby preventing toner depletion and image defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the toner layer is kept thin to reduce toner consumption, then toner usage is reduced, but image quality deteriorates due to afterimages and development ghosts
Solution Approach 1:
The patent applies dynamics by making the pressing force between the supply roller and developing roller variable rather than constant. The control section adjusts the pressing force based on cumulative drive time, increasing it after high coverage rate images are formed to ensure sufficient toner supply and prevent afterimages, while using lower pressing force during normal operation to maintain thin toner layers and reduce consumption.
Solution Approach 2:
The patent changes the parameter of pressing force dynamically. The control section modifies the pressing force between the supply roller and developing roller based on the cumulative drive time and image coverage rate, transitioning from a fixed parameter to a variable one that adapts to different printing conditions to balance toner consumption and image quality.
2Reliability
If the toner layer thickness is increased to prevent afterimages, then image quality improves, but toner consumption increases
Solution Approach 1:
The patent uses dynamics to adjust the pressing force between the supply roller and developing roller based on cumulative drive time. This dynamic adjustment ensures that the toner layer thickness is optimized for each printing condition, preventing afterimages only when necessary (after high coverage images) while maintaining thin layers during normal operation to reduce toner consumption.
Solution Approach 2:
The patent implements periodic action by cyclically adjusting the pressing force based on the cumulative drive time. After a high coverage rate image is formed, the pressing force is increased to replenish toner, then reduced again for subsequent normal printing, creating a periodic pattern of force adjustment that balances image quality and toner consumption over time.
3Device complexity
If a constant pressing force is applied between supply roller and developing roller, then device complexity is reduced, but toner supply consistency deteriorates under varying print conditions
Solution Approach 1:
The system performs self-service by automatically adjusting the pressing force between the supply roller and developing roller based on cumulative drive time and image coverage rate. The control section monitors printing conditions and autonomously modifies the pressing force without manual intervention, ensuring consistent toner supply adaptation to varying print conditions while maintaining relatively simple hardware.
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 stable image density and reduced toner consumption by maintaining the potential difference between supply and development voltages, preventing afterimages and improving image quality while controlling toner usage effectively.
Implementation Method 1
when the toner passes below the regulation blade, the surface of the developing roller and the toner become charged by friction therebetween
Implementation Method 2
The control section performs control so that, as a cumulative drive time of the developing device from a start of use of the developing device increases, the supply voltage Vsdc becomes larger than a reference supply voltage and the development voltage Vdc becomes smaller than a reference development voltage, thus executing control to vary the development voltage Vdc and the supply voltage Vsdc so as to increase a potential difference Vsdc−Vdc between the supply voltage Vsdc and the development voltage Vdc
Data Source
AI summary
An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a development voltage power supply, and a control section. The developing device includes a development container for containing a non-magnetic one-component developer composed only of a toner, a developer carrying member having an outer circumferential surface on which a toner layer is formed, and a toner supply member that supplies the toner to the developer carrying member. The control section performs control so that, as a cumulative drive time of the developing device increases, a supply voltage Vsdc becomes larger than a reference supply voltage and a development voltage Vdc becomes smaller than a reference development voltage, thus executing control to vary the development voltage Vdc and the supply voltage Vsdc so as to increase a potential difference Vsdc−Vdc between the supply voltage Vsdc and the development voltage Vdc.