Developing Device Air Pressure Relief Structure
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Solution Overview
Problem
As printing speed increases, the high rotation speed of the developing roller in electrophotographic image forming devices leads to increased air pressure, causing excessive discharge of developer through the discharge port, which reduces the developer amount in the developing device and results in decreased image density.
Innovation Solution
The developing device incorporates an air pressure relief structure with an air discharge port and internal circulation path, allowing partial air discharge before reaching the developer discharge port, reducing air pressure and preventing excessive developer discharge, while maintaining an appropriate developer level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the developing roller rotates at high speed to increase printing speed, then productivity is improved, but air pressure increases causing excessive developer discharge and image density degradation
Solution Approach 1:
The air discharge function is segmented from the developer discharge function by providing a separate air discharge port distinct from the developer discharge port. This allows independent control of air pressure relief and developer discharge, enabling high-speed rotation without excessive developer loss while maintaining image density.
Solution Approach 2:
A dedicated air discharge port acts as an intermediary channel that allows trapped air to escape separately from the developer discharge path. This intermediary structure prevents air pressure buildup that would otherwise cause unwanted developer discharge through the developer discharge port, resolving the contradiction between high-speed operation and precise developer control.
2Productivity
If the developing roller rotates at high speed, then productivity is improved, but air pressure increases causing excessive developer discharge
Solution Approach 1:
The air discharge function is segmented from the developer discharge function by providing a separate air discharge port distinct from the developer discharge port. This allows independent control of air pressure relief and developer discharge, enabling high-speed rotation without excessive developer loss while maintaining image density.
Solution Approach 2:
The harmful air pressure is extracted separately through a dedicated air discharge port, removing it from the system before it can cause excessive developer discharge. This extraction of the problematic element (air) through a separate pathway prevents the substance loss (developer) that would occur if air and developer were discharged together.
3Productivity
If air pressure is increased due to high rotation speed, then productivity is improved, but developer discharge control becomes difficult
Solution Approach 1:
The air discharge function is segmented from the developer discharge function by providing a separate air discharge port distinct from the developer discharge port. This allows independent control of air pressure relief and developer discharge, enabling high-speed rotation without excessive developer loss while maintaining image density.
Solution Approach 2:
The separate air discharge port provides a pressure relief feedback mechanism that automatically regulates internal air pressure during high-speed rotation. By allowing air to escape through the dedicated air discharge port, the system maintains stable pressure conditions that facilitate precise developer discharge control through the developer discharge port, improving ease of operation at high printing speeds.
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 effectively reduces the influence of increased air pressure on developer discharge speed and amount, preventing excessive developer discharge and maintaining optimal developer levels, thus ensuring consistent image density.
Implementation Method 1
a structure for releasing an internal air pressure is provided in the developing device
Data Source
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AI summary
The developing device includes a developing roller, a developer conveying unit, a developer discharge unit, and an air discharge port. The developer conveying unit includes a developing chamber provided with the developing roller and extending in a longitudinal direction of the developing roller, a stirring chamber arranged in parallel to the developing chamber, and a barrier wall having a first communication port and a second communication port, at respective ends in the longitudinal direction, to connect the developing chamber with the stirring chamber. The developer discharge unit extends from the developer conveying unit in the longitudinal direction of the developing roller and includes a developer discharge port to discharge excess developer. The air discharge port is to house a filter to filter a developer, the air discharge port being provided between the developer conveying unit and the developer discharge unit to discharge air in the developer conveying unit.