Developing Device Upstream Restriction Portion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional developing devices experience uneven developer supply due to the close proximity of the stirring conveyance member and restriction member, leading to inconsistent developer layer thickness and image density when inclined, causing defects like uneven density, clogging, and carrier adhesion.
Innovation Solution
A developing device with a hollow cylindrical developer carrier, a feed screw, a magnetic restriction member, and an upstream restriction portion, where the restriction member and upstream portion are positioned to stabilize the developer supply, ensuring consistent layer thickness and conveying amount, with the restriction member disposed above the carrier's central axis and the upstream portion controlling the developer flow before reaching the restriction member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the stirring conveyance member and restriction member are disposed at positions close to each other, then the device structure is compact, but the developer supply amount becomes unstable when the device is inclined, causing uneven density
Solution Approach 1:
The upstream restriction portion is positioned upstream of the restriction member to preliminarily control and stabilize the developer supply amount before it reaches the restriction member. This preliminary action ensures that even when the device is inclined, the developer flow is regulated in advance, preventing unstable supply and maintaining consistent image density.
2Manufacturing precision
If the upstream restriction portion is positioned downstream, then the restriction member can effectively control layer thickness, but the developer supply amount becomes unstable due to inclination effects
Solution Approach 1:
By positioning the upstream restriction portion upstream of the restriction member, the system performs preliminary control of developer supply. This ensures that the developer amount is stabilized before reaching the restriction member, allowing the restriction member to effectively control layer thickness without suffering from inclination-induced supply instability.
3Length of moving object
If the restriction member and upstream restriction portion are disposed outside the 90° range, then the developer flow path is longer, but the conveying amount becomes unstable and causes clogging and carrier adhesion
Solution Approach 1:
The invention optimizes the positional parameters of the restriction member and upstream restriction portion by constraining them within a 90° range. This parameter optimization ensures that the developer flow path length is appropriate, preventing both insufficient control and excessive path length that would cause clogging and carrier adhesion, thereby eliminating harmful effects.
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
The solution stabilizes the developer conveying amount, preventing defects such as uneven density, clogging, and carrier adhesion by maintaining consistent developer flow and layer thickness, regardless of device inclination or rotation speed.
Implementation Method 1
The restriction member has a magnetic property and is formed in a solid cylindrical shape
Implementation Method 2
The feed screw is configured to rotate to feed the developer to the developer carrier
Data Source
AI summary
A restriction member is disposed above a central axis of a developing roller. An upstream restriction portion is disposed on an upstream side of the restriction member in a conveyance direction of a developer and configured to restrict an amount of the developer that is to be supplied to the restriction member. The central axis of the developing roller and a rotation axis of a feed screw extend in parallel with each other. In a view of a developing device seen in a direction in which the central axis and the rotation axis extend, the restriction member and the upstream restriction portion are disposed within a range of 90°, to the upstream side in the conveyance direction, from an intersection point at which a straight line connecting the central axis and the rotation axis intersects with an outer circumferential surface of the developing roller.