Developing Unit Control for Low-Transferability Media
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Solution Overview
Problem
Image forming apparatuses face challenges in maintaining image transferability on media with low transferability, such as embossed or rough paper, due to deteriorated toner accumulation, leading to quality issues like white spots.
Innovation Solution
An image forming apparatus with a developing unit that applies a developing voltage with a reduced AC component on media with low transferability, minimizing the use of deteriorated toner and adjusting the developing conditions to prevent toner deterioration, including a second control mode with lower peak-to-peak voltage and potentially altered DC component to ensure better image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the same developing conditions are used for different media types, then the device complexity is reduced and operation is simplified, but image transferability deteriorates on media with low transferability such as embossed or rough paper
Solution Approach 1:
The developing conditions are made dynamic and adjustable based on the medium type being used. The control unit varies the AC component voltage parameters (peak-to-peak voltage and/or frequency) according to the transferability characteristics of the medium, allowing the system to adapt to different paper types while maintaining optimal image transfer quality
Solution Approach 2:
The patent changes the electrical parameters of the developing voltage, specifically the AC component's peak-to-peak voltage and frequency, to match the transferability requirements of different media. By adjusting these parameters, the system optimizes toner transfer efficiency for each medium type without requiring complete redesign of the developing mechanism
2Illumination intensity
If a high AC component voltage is applied to improve image density, then the image density increases, but deteriorated toner accumulates faster in the developing device
Solution Approach 1:
The system implements periodic action by alternating between normal developing operations and maintenance operations. During maintenance operations, the AC component voltage is reduced or the developing device is paused, allowing deteriorated toner to be removed or replaced, thereby preventing toner quality degradation while maintaining image density during normal operation
Solution Approach 2:
The patent applies discarding and recovering by removing deteriorated toner from the developing device through maintenance operations and replacing it with fresh toner. This ensures the developing device always contains high-quality toner capable of producing dense images without degradation from accumulated deteriorated particles
3Productivity
If the developing operation continues without interruption to maintain productivity, then the output speed is maintained, but deteriorated toner accumulates leading to image quality degradation
Solution Approach 1:
The system performs preliminary maintenance actions before toner deterioration significantly impacts image quality. The control unit monitors developing operation duration and schedules toner replacement or developing device maintenance in advance, preventing image quality degradation while minimizing interruptions to productivity
Solution Approach 2:
The patent maintains continuity of useful action by implementing maintenance operations that minimize interruption to the image forming process. The system schedules brief maintenance intervals during which toner is replaced or the developing device is cleaned, allowing productivity to resume immediately afterward with restored image quality
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 solution effectively reduces the transfer of deteriorated toner, enhancing image quality on low-transferability media by optimizing developing conditions, thereby minimizing white spots and maintaining image quality across different paper types.
Implementation Method 1
a developing unit configured to apply a developing voltage in which an AC component is superimposed on a DC component between the image carrier and the developer carrying unit so as to develop an electrostatic latent image formed on the image carrier with a developer carried by the developer carrying unit
Implementation Method 2
a transfer unit configured to electrostatically transfer the image, which is carried on the image carrier and developed by the developing unit, onto media of different types
Data Source
AI summary
An image forming apparatus includes an image carrier that carries an image, a developing unit that applies a developing voltage to develop an electrostatic latent image formed on the image carrier with a developer, a transfer unit that electrostatically transfers the image onto media of different types, and a development controller that controls a developing operation of the developing unit. The development controller has a first control mode for a first medium, and a second control mode for a second medium having a lower transferability than the first medium. In the first control mode, the developing unit applies the developing voltage according to a first developing condition. In the second control mode, the developing unit applies the developing voltage according to a second developing condition in which a developing property is reduced as compared with the first developing condition.