Developing Apparatus Screw Port Configuration
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Solution Overview
Problem
In function separated type developing apparatuses, the fluidity of the developer can drop, leading to increased surface levels in the agitating chamber, which can cause image defects due to inadequate delivery to the developing chamber and excessive discharge, affecting the coating process and image quality.
Innovation Solution
The developing apparatus includes a configuration with a second wall defining a third communication port upstream of the discharge portion, which faces part of the return portion of the agitating screw, optimizing the delivery of developer from the agitating chamber to the developing chamber and controlling the discharge through a discharge port, ensuring adequate developer distribution and preventing excessive discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the width of the communication port is reduced to suppress the apparatus from enlarging in the conveyance direction of the screw, then the apparatus size is reduced, but the amount of developer delivered from the agitating chamber to the developing chamber decreases and the amount of developer discharged out of the discharge port increases
Solution Approach 1:
The communication port is divided into two separate ports: a first communication port for delivering developer from the agitating chamber to the developing chamber, and a second communication port for discharging excess developer. This segmentation allows independent control of delivery and discharge functions, enabling the apparatus to maintain compact size while properly managing developer flow distribution.
Solution Approach 2:
The discharge port acts as an intermediary mechanism that provides a controlled pathway for excess developer to exit the system. By introducing this intermediate discharge path, the system can maintain smaller communication ports while still preventing developer accumulation and ensuring proper flow balance between chambers.
2Ease of operation
If the return screw is provided at a position facing the communication port, then the discharge of developer can be controlled, but most of the developer is delivered to the developing chamber before reaching the discharge port
Solution Approach 1:
The return screw is divided into a first return screw positioned at the communication port for controlled discharge, and a second return screw positioned downstream for additional flow control. This segmentation creates multiple control points that can independently regulate developer flow, preventing the single-point control limitation where most developer reaches the developing chamber before discharge control can act.
Solution Approach 2:
The first return screw positioned at the communication port performs preliminary action by controlling developer discharge at the point where developer enters the developing chamber. This preliminary control prevents excessive developer accumulation before it can be delivered to the developing chamber, addressing the timing issue where discharge control is too late in the single-screw configuration.
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 enhances the delivery of developer to the developing chamber, preventing image defects like density unevenness and coating failures, while maintaining controlled discharge, ensuring consistent developer distribution and improved image quality.
Implementation Method 1
a second screw disposed within the second chamber, including a first conveyance portion configured to convey the developer in a second direction opposite to the first direction
Implementation Method 2
a return portion provided downstream in the second direction and downstream of the first communication port and configured to convey the developer in the first direction
Implementation Method 3
a discharge portion provided in the second chamber downstream of the return portion in the second direction to discharge the developer out of the second chamber
Data Source
AI summary
A developing apparatus includes a first screw disposed within a first chamber and conveying developer in a first direction, a second screw disposed within a second chamber and having a conveyance portion conveying the developer in a second direction opposite to the first direction and a return portion provided downstream of a first communication port in a first wall dividing the first and second chambers. A discharge portion in the second chamber, downstream of the return portion, discharges the developer out of the second chamber, and a second wall through which a third communication port is disposed upstream of the discharge portion is defined to deliver the developer from the second chamber to the first chamber. The second wall faces at least a part of the return portion in a view from a horizontal direction such that a lower end of the third communication port is located above a lower end of the first communication port.