Developing Device Transport Member Screw-Less Discharge Aperture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatus using the premixed developing system, the degradation of the carrier within the developing device leads to unstable image quality due to excessive discharge of developing agent, resulting in reduced toner charge and image density, which existing solutions fail to adequately address.
Innovation Solution
A developing device with transport members featuring a screw portion and a discharge aperture positioned opposite to an area without a screw portion, where the discharge aperture is shorter than the screw-less area, effectively prevents the discharge of developing agent thrown up by the transport member, maintaining consistent image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a discharge aperture is provided in the wall of the developing device to discharge excess developing agent, then the carrier charging capacity is maintained, but developing agent is excessively discharged including the necessary developing agent, resulting in insufficient developing agent and reduced image quality
Solution Approach 1:
The discharge aperture is positioned at a specific location on the transport member where the screw portion is not formed, creating a localized discharge zone. This local positioning ensures that only excess developing agent is discharged while preserving the necessary developing agent for image formation, resolving the contradiction between maintaining carrier charging capacity and preventing excessive discharge.
Solution Approach 2:
The transport member is segmented into different regions: a screw portion region for transporting developing agent and a screw-less region with the discharge aperture for controlled discharge. This segmentation allows the system to distinguish between developing agent that needs to be transported and developing agent that should be discharged, preventing excessive loss while maintaining adequate supply.
2Loss of substance
If the screw portion is removed from the transport member to reduce developing agent discharge, then the discharge of thrown-up developing agent is reduced, but the transport capability of the screw portion is compromised
Solution Approach 1:
The transport member is divided into functional segments: the screw portion maintains full transport capability where needed, while the screw-less region with the discharge aperture handles the discharge function. This segmentation allows the system to retain transport productivity while reducing excessive discharge of developing agent.
Solution Approach 2:
The discharge function is extracted from the screw portion by providing a separate discharge aperture in the screw-less region. This extraction allows the screw portion to focus on transport capability while the discharge aperture handles the discharge function, avoiding the compromise of transport capability that would result from removing the screw portion entirely.
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 significantly reduces the discharge of developing agent, stabilizing the image quality by ensuring the correct amount of carrier is maintained within the device, thereby enhancing the consistency and density of output images.
Implementation Method 1
a plurality of transport members which have a screw portion formed on a shaft portion, and which transport the developing agent housed within the device in a longitudinal direction
Implementation Method 2
at the position in opposition to the photosensitive drum, the toner in the two part developing agent adheres to the latent image on the photosensitive drum
Data Source
AI summary
A developing device, process cartridge, and image forming apparatus, include at least one developing roller. A plurality of transport members with screw and shaft portions, transport developing agent housed within the device in a longitudinal direction, and form a circulation path. A discharge aperture, formed in a transport path wall of one transport member, discharges developing agent to the outside when a surface of the developing agent transported by one of the plurality of transport members exceeds a predetermined height. The one transport member is adjacent to the developing roller that supplies the developing agent and includes, in a part in the longitudinal direction, an area on which the screw portion is not formed. The discharge aperture is disposed opposite to the area on which the screw portion is not formed, and the length of the discharge aperture is formed smaller than that of the area in the longitudinal direction.