Feeding Screw Pitch Ratio for Developer Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional developing devices face challenges in maintaining effective developer delivery through communication ports, leading to stagnation and image defects due to uneven developer distribution, especially when process speed increases.
Innovation Solution
The developing device incorporates a feeding screw with a first helical blade and a returning portion having a plurality of threads, where the pitch of the returning blade is equal to or greater than the pitch of the feeding blade, and the number of threads times the length of the returning blade exceeds the pitch of the returning blade, ensuring balanced developer delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a returning screw with a plurality of threads is provided with a smaller pitch than the feeding screw, then the developer feeding amount per rotation is increased, but the developer does not readily move toward the communication ports causing delivery property deterioration
Solution Approach 1:
The patent applies parameter changes by adjusting the pitch relationship between the feeding screw and returning screw. Specifically, it sets the pitch of the returning screw (P2) to be equal to or greater than the pitch of the feeding screw (P1), which reverses the conventional approach. This parameter adjustment ensures that while maintaining adequate feeding amount, the developer flow velocity and direction are optimized to readily move toward communication ports, preventing delivery property deterioration.
2Quantity of substance
If the pitch of the returning screw is smaller than the feeding screw, then the developer feeding amount is increased, but the developer moves toward the returning screw side excessively causing stagnation
Solution Approach 1:
The patent resolves this contradiction by changing the pitch parameter relationship, setting P2≥P1. This ensures that the returning screw does not over-feed developer in one location, maintaining uniform distribution throughout the developing container and preventing stagnation while still achieving adequate feeding amounts.
3Productivity
If process speed is increased, then productivity is improved, but developer distribution becomes uneven causing image defects
Solution Approach 1:
The patent addresses this contradiction through parameter changes in the screw pitch relationship. By setting the returning screw pitch (P2) equal to or greater than the feeding screw pitch (P1), the system maintains stable developer circulation and distribution even at increased process speeds, preventing the uneven distribution that would otherwise cause image defects while preserving high productivity.
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 maintains stable developer delivery and prevents excessive discharge, ensuring consistent image quality even at increased process speeds by balancing the developer feeding amount per rotation and preventing peak shifts, thus reducing the likelihood of density non-uniformity and overflow.
Implementation Method 1
a first helical blade configured to feed the developer in a first direction from the first communicating portion toward the second communicating portion
Implementation Method 2
a second helical blade in the form of a plurality of threads configured to feed the developer fed to the feeding portion in a second direction opposite to the first direction
Data Source
AI summary
A developing device includes a developer carrying member, a first chamber, a second chamber, a first communicating portion, a second communicating portion, and a feeding screw, provided in the second chamber, including a feeding portion having a first helical blade and including a returning portion having a second helical blade in the form of a plurality of threads, the feeding portion and the returning portion being provided so that a boundary portion therebetween opposes the second communicating portion. The first helical blade and the second helical blade satisfy the following relationship: P2≥P1, where P1 is a pitch, or lead, of the first helical blade and P2 is a lead of the second helical blade.