Developing Apparatus Mountain-Shaped Guide for Stable Toner Agitation
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Solution Overview
Problem
Electrophotographic developing apparatuses face challenges in maintaining stable developer circulation and discharge, especially when inclined, leading to issues like developer leakage, toner scattering, and image defects due to inadequate agitation and supply of toner to the developing roller.
Innovation Solution
A developing apparatus with a housing that includes a developer supplying and recovering portion, agitating portion, and a projection-shaped guide, featuring a mountain-shaped cross-sectional guide and agitating members that convey and agitate the developer effectively, ensuring proper circulation and discharge even when the apparatus is inclined.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the apparatus operates at high printing rates, then productivity is improved, but the toner becomes insufficient and uncharged toner is replenished, causing image deterioration such as toner scattering and toner fogging
Solution Approach 1:
The patent applies preliminary action by providing a sufficient amount of charged toner in advance within the developing device before high-speed printing begins. The developing device is designed to hold an adequate reserve of charged toner that can sustain high printing rates without requiring frequent replenishment, thereby preventing image deterioration during high-speed operation.
Solution Approach 2:
The patent implements feedback through a controller that monitors the charging state of toner and adjusts the replenishment timing and amount accordingly. The controller determines when uncharged toner needs to be replenished based on usage patterns and ensures that replenishment occurs at optimal moments to maintain image quality while supporting high printing rates.
2Loss of time
If the toner is replenished and conveyed without sufficient agitation, then the replenishment process is faster, but image deterioration such as toner scattering and toner fogging occurs
Solution Approach 1:
The patent applies dynamics by providing multiple agitating members that can operate at different speeds and intensities. The agitating members are designed to dynamically adjust their agitation action to ensure thorough mixing of replenished toner with the existing developer, achieving sufficient agitation within the available time before toner is conveyed to the developing roller.
Solution Approach 2:
The patent segments the agitation function into multiple agitating members positioned at different locations within the developing device. This segmentation allows different regions of the toner to be agitated simultaneously by different members, reducing the overall time required for sufficient agitation while maintaining image quality.
3Reliability
If a plurality of agitating members are provided to agitate the developer, then the agitation effectiveness is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple functions into the agitating members, which simultaneously perform agitation, conveyance, and charging functions. By combining these functions into integrated components rather than separate elements, the patent reduces overall device complexity while maintaining effective developer agitation through the plurality of agitating members.
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 stable developer supply and agitation, preventing issues like toner scattering and leakage, ensuring high-quality images even at high printing rates and maintaining image quality during successive high-speed printing.
Implementation Method 1
a first agitating member arranged in the developer agitating portion so as to extend along a direction of a rotating axis of the conveying member adjacent to the partition wall, conveying the developer in an inverse direction to the conveying direction by the conveying member while agitating
Implementation Method 2
a toner charged due to triboelectric charging between the toner and a carrier is attached to an electrostatic latent image formed on an image carrier so as to develop
Implementation Method 3
a toner charged due to triboelectric charging between the toner and a carrier is attached to an electrostatic latent image formed on an image carrier so as to develop
Data Source
AI summary
A housing of a developing apparatus is provided with a conveying member and first and second agitating members. A guide is provided in an inner bottom surface of the housing between the first and second agitating members. The guide has a mountain shape with a wide foot portion in a cross sectional shape which is orthogonal to an axial direction of rotating shafts of the first and second agitating members. The first and second agitating are arranged in such a manner that gaps between respective outermost portions thereof and the inner bottom surface of the housing and the guide become equal to or more than 1.5 mm and less than 3 mm. A discharge portion is provided on a downstream side of a developer agitating portion in a developer conveying direction of the first and second agitating members.