Trickle Developing Apparatus Toner Concentration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The trickle developing apparatus for electrophotographic image forming machines faces challenges in maintaining accurate toner concentration detection due to changes in developer amount, leading to errors in toner concentration measurement and inconsistent image formation, especially when using a two-component developer system.
Innovation Solution
A developing apparatus with stirring members, a developer holder, a toner concentration detecting sensor, a developer amount estimating sensor, a discharging mechanism, and a controller that calculates and adjusts the toner and carrier replenishment based on the detected toner concentration and estimated developer amount, using different sensing states to accurately determine the toner concentration and developer level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the amount of carrier stored in the developing apparatus is increased to extend the life of the developing apparatus, then the operating duration is improved, but the device size becomes larger
Solution Approach 1:
The patent implements a trickle developing system where deteriorated developer is continuously discharged and fresh developer is replenished. The developing apparatus includes a developer supply tank that stores additional developer, and a replenishment mechanism that gradually adds fresh developer to the developing tank while discharged deteriorated developer is removed. This allows extended operation without increasing the main developing tank size, as the supply tank acts as a reservoir that feeds fresh developer over time.
2Reliability
If fresh developer is gradually replenished and deteriorated developer is gradually discharged in the trickle developing apparatus, then the charging performance is maintained, but the amount of developer inside the developing apparatus changes causing toner concentration detection error
Solution Approach 1:
The patent employs a feedback control system where a toner concentration detection sensor continuously monitors the toner concentration in the developer. The controller receives this detection signal and compares it against a predetermined reference value. When the detected concentration deviates from the reference, the controller automatically adjusts the replenishment amount of fresh developer to maintain the optimal toner concentration. This closed-loop feedback mechanism ensures accurate toner concentration detection despite the continuous replenishment and discharge operations.
Solution Approach 2:
The patent replaces mechanical volume-based developer amount detection with a magnetic detection system. A toner concentration detection sensor based on magnetic properties detects the toner concentration by measuring the magnetic characteristics of the developer, rather than relying on mechanical volume measurements. This substitution provides more accurate and reliable detection that is not affected by the changing developer volume during trickle replenishment operations.
3Ease of manufacture
If the magnetic detection method is used to detect toner concentration, then the cost of sensor and staining properties are improved, but errors occur in detection due to changes in bulk density
Solution Approach 1:
The patent addresses the bulk density interference in magnetic detection by implementing a dual-detection system. In addition to the magnetic detection sensor that provides cost-effective and stain-resistant monitoring, an optical detection sensor is also employed. The optical sensor detects toner concentration by measuring light absorption or reflection properties. By combining both detection methods, the system can distinguish between changes in toner concentration and changes in bulk density, as these two parameters affect the magnetic and optical properties differently. This allows accurate toner concentration measurement while maintaining the cost and durability advantages of magnetic detection.
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 accurate toner concentration measurement and appropriate developer replenishment, maintaining optimal image formation quality over an extended period by addressing the issues of toner concentration variability and developer amount changes.
Implementation Method 1
a toner concentration detecting sensor for detecting the toner concentration inside the developer tank
Implementation Method 2
the two-component developing system in which toner and carrier are used as the main components of the developer, in which the toner and carrier are charged by friction contact therebetween
Data Source
AI summary
The developing apparatus, having stirring members for conveying and stirring developer-tank-contained developer and a developer holder, comprises a developer replenishing tank; a magnetic-type toner concentration detecting sensor; a trickle-type discharging mechanism; conveying state switching device for temporarily blocking the flow of the developer-tank-contained developer and for temporarily switching the circulating state of the developer-tank-contained developer to the staying state thereof; and a controller for controlling replenishment operation for replenishing the toner and the carrier for replenishment to the developer tank when the toner concentration is lower than a predetermined reference toner concentration, wherein the controller determines the amounts of the toner and the carrier to be replenished on the basis of the calculated toner concentration and the estimated amount of the developer.