Developer Supply Member Segmentation for Toner Stirring
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Solution Overview
Problem
Conventional electrophotographic image forming apparatuses face challenges in efficiently feeding and stirring toner in upsized developer accommodating portions without causing image defects or increasing costs, particularly due to the need for precise control of elastic sheet dimensions and the use of multiple stirring means.
Innovation Solution
A developing device with a shaft member and a feeding member featuring specific geometric relationships between its components, allowing a first feeding portion to enter the developing chamber while preventing contact with the developer carrying member, and a second feeding portion that does not enter the chamber, ensuring effective toner feeding and stirring without image defects or excessive cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the elastic sheet is elongated to stir toner in an upsized developer accommodating portion, then the toner stirring effectiveness is improved, but the elastic sheet free end portion enters the developing chamber and contacts the developer carrying member, causing image defects
Solution Approach 1:
The elastic sheet is divided into multiple segments along its length, with each segment having different functional characteristics. The first portion has sufficient length to reach and stir toner in the upsized developer accommodating portion, while the second portion is shortened to prevent entry into the developing chamber, thus eliminating image defects while maintaining stirring effectiveness.
Solution Approach 2:
Different portions of the elastic sheet are given different lengths and functional properties. The first portion (near the rotation center) is designed with sufficient length for effective toner stirring, while the second portion (free end) is truncated to a specific length that prevents it from entering the developing chamber, creating local quality differentiation to resolve the contradiction.
2Ease of operation
If multiple stirring means are provided in the developer accommodating portion, then the toner stirring effectiveness is improved, but the manufacturing cost is increased
Solution Approach 1:
The elastic sheet is designed to perform multiple functions: it both feeds toner from the developer accommodating portion and stirs toner within the same component. By making the elastic sheet sufficiently long and positioning it to contact the developer carrying member, a single component achieves what would traditionally require multiple separate stirring means, thereby reducing manufacturing cost while maintaining effectiveness.
Solution Approach 2:
The feeding function and stirring function are merged into a single elastic sheet component. The first portion of the elastic sheet performs feeding while the same component's extended length enables it to also perform stirring in the developer accommodating portion, eliminating the need for separate stirring means and reducing overall system complexity and cost.
3Object-affected harmful factors
If the dimension of the elastic sheet free end portion is strictly controlled, then image defects are prevented, but the manufacturing precision requirements are increased
Solution Approach 1:
The elastic sheet is designed with a predetermined truncated length from the outset, rather than requiring post-manufacturing adjustment or strict dimensional control during production. The second portion is intentionally made shorter than the distance to the developing chamber opening, creating a built-in safety margin that prevents image defects without imposing stringent dimensional control requirements on the manufacturing process.
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 allows for efficient feeding and stirring of toner in the developing chamber, reducing toner packing and maintaining image quality while keeping costs low by avoiding the need for precise elastic sheet control and multiple stirring means.
Implementation Method 1
a stirring means 26 rotatable in an arrow RR direction is provided. Further, the stirring means 26 is constituted by a shaft member 60 as a base member and the elastic sheet 50 as a developer feeding member
Implementation Method 2
the case where the elastic sheet free end portion enters the developing chamber to contact a developer carrying member exists, so that there was a liability that an image defect was caused
Data Source
AI summary
A developing device includes a developer carrying member for developing an electrostatic image with a developer, a developer container including a developing opening, and a developer supplying member for supplying the developer to a developing chamber through the developing opening. The developer supplying member includes a shaft member rotatably supported by the developer accommodating portion and a feeding member, wherein the feeding member includes a first feeding portion and a second feeding portion. The first feeding portion is provided in a downstream side, and the second feeding portion is provided in an upstream side with respect to a rotational direction of the shaft member.