Toner Supply Control via Partitioned Developing Vessel
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Solution Overview
Problem
In image forming apparatuses using dual-component developers, toner empty detection is delayed due to the location of toner concentration detecting sensors, leading to increased carrier adherence issues, and existing technologies do not effectively manage toner concentration variations.
Innovation Solution
An image forming apparatus with a toner supply detecting sensor, a toner concentration controller, and a paper conveyance detecting sensor that samples toner supply detection at optimal times, using a developer container with a partitioned structure and a developing roller to agitate and convey the developer, ensuring precise toner supply and detection of toner empty states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a toner concentration detecting sensor is used to monitor toner levels in the developing device, then toner supply control is improved, but detection precision is reduced due to the sensor's location away from the toner supply port
Solution Approach 1:
The developing device is divided into multiple sections: a toner supply section near the supply port and a detection section where the sensor is positioned. The sensor detects toner concentration in the detection section, and based on this information, the system controls toner supply to the supply section, segmenting the monitoring and control functions to optimize both detection precision and supply control reliability.
Solution Approach 2:
The patent introduces an intermediary detection mechanism where the sensor indirectly monitors toner concentration by detecting the state of the developer (magnetic carrier) in the detection section. This intermediary detection allows precise inference of toner empty states without requiring the sensor to be positioned directly at the supply port, thus maintaining measurement precision while ensuring reliable supply control.
2Manufacturing precision
If toner supply is continuously monitored and controlled, then image quality is improved, but device complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The patent extracts the essential detection function by positioning the sensor to detect only the critical parameter (toner empty state) rather than continuously monitoring all toner concentration variations. This extraction of the key detection need simplifies the control system while maintaining sufficient image quality, avoiding unnecessary complexity from over-monitoring.
Solution Approach 2:
The developing device structure itself is designed to facilitate detection, where the natural flow and distribution of developer creates detectable patterns that indicate toner concentration. The system uses the existing developer circulation and magnetic carrier behavior to provide self-indicating information about toner status, reducing the need for complex external sensing and 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
This configuration allows for accurate detection of toner empty states, preventing carrier adherence and ensuring precise toner concentration control, resulting in high-quality image printing.
Implementation Method 1
a toner and a carrier, which are agitated in the developing device and frictionally rubbed with each other to thereby produce appropriately tribo-electrified toner
Implementation Method 2
The toner thus supplied to the developing roller is moved by electrostatic attraction to the electrostatic latent image formed on the photoreceptor drum
Data Source
AI summary
An image forming apparatus includes: a developing device having a developing vessel, a developing roller and a toner supply port; a toner supply device; a toner supply detecting sensor for detecting the toner concentration inside the developing vessel; a toner concentration controller for directing toner supply; a toner empty detector; and a sheet conveyance detecting sensor. The toner concentration controller has a toner supply device control function; and a toner supply stopping function of stopping toner supply when the last sheet of image printout being executed has passed by the predetermined position in the sheet conveyance path.