Elastic Regulating Blade with Projections for Toner Leakage Prevention
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Solution Overview
Problem
Thin metal developing blades in image forming apparatuses often cause toner leakage due to deformation of sealing members, leading to increased pressure between the blade and roller, which can result in image defects from toner adherence.
Innovation Solution
A developing device with a plate-like elastic regulating blade and an elastic seal, where the blade includes a second projection approaching the developer bearing member and a first projection away from it, with the elastic seal compressed to prevent toner leakage and maintain optimal contact pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a thin metal blade is used as a developing blade, then the blade thickness is reduced to 1 mm or less, but the sealing member deforms and crawls under the blade causing toner leakage
Solution Approach 1:
A pressing member is introduced as an intermediary component between the sealing member and the developing blade. This pressing member applies controlled pressing force to the sealing member, preventing it from deforming and crawling under the thin metal blade, thereby maintaining reliable sealing performance while allowing the use of thin blades
Solution Approach 2:
The pressing force applied to the sealing member is controlled within a specific range (0.01 to 0.05 MPa) to prevent deformation without causing excessive contact pressure between the blade and developing roller. This parameter control resolves the contradiction by optimizing the sealing pressure while maintaining blade thinness
2Reliability
If the sealing member is pressed to attach to the developing blade, then sealing is improved, but the contact pressure between blade and roller increases causing toner adherence
Solution Approach 1:
The pressing force on the sealing member is precisely controlled within the range of 0.01 to 0.05 MPa. This parameter optimization ensures adequate sealing while preventing excessive contact pressure between the developing blade and roller, thereby avoiding toner adherence and image defects
3Shape
If the sealing member deforms and crawls under the blade, then sealing position shifts, but abutting pressure increases causing toner circulation failure
Solution Approach 1:
The pressing member acts as a mediator that maintains the sealing member in its proper position prevents crawling under the blade. By applying controlled pressure through this intermediary, the sealing member remains correctly positioned, preventing toner circulation failure while maintaining adequate sealing
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
Prevents toner leakage and maintains optimal contact pressure between the developing blade and roller, enhancing image quality by preventing toner adherence and deformation issues.
Implementation Method 1
an elastic seal provided to be compressed between the developer bearing member and the developer container in an area of the developer container outside of the regulating blade in the rotation axis direction, configured to seal a gap between the developer bearing member and the developer container
Implementation Method 2
a regulating blade including a plate-like elastic portion, configured to regulate a thickness of a layer of the developer born on a surface of the developer bearing member
Data Source
AI summary
A developing device includes a developer bearing member, a developer container, a regulating blade including a plate-like elastic portion, and an elastic seal sealing, and a pressing member pressing the elastic seal, wherein the plate-like elastic portion includes a metal plate, a second projection projecting from a second surface of the metal plate facing the developer bearing member, and a first projection projecting from a first surface opposite to the second surface of the metal plate, and wherein a projecting amount of the first projection is greater than a projecting amount of the second projection, wherein a top surface of the second projection contacts the surface of the developer bearing member, and an end surface of the first projection contacts an end surface of the elastic seal in the rotation axis direction.