Curved Contact Regulating Member for Toner Thickness Control
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Solution Overview
Problem
Existing electrophotographic image forming apparatuses face issues with developing hysteresis, leading to ghost image generation due to uneven toner layer thickness and charge distribution, which affects image quality and longevity.
Innovation Solution
A developing apparatus with a regulating member featuring a support member fixed to a developer container and a contact curved surface that decreases pressure as it moves along the developer carrying member, ensuring uniform toner layer thickness and charge distribution by using a concave curved surface and a step surface to manage toner flow and charging effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a blade-type regulating member is used to regulate toner layer thickness, then the charge amount can be controlled, but ghost images are generated due to developing hysteresis
Solution Approach 1:
The regulating member features a curved contact surface that contacts the developing roller along an arc rather than at a single point. This curved surface distributes the regulating action over a longer toner transport path, ensuring more uniform toner layer thickness and charge distribution, thereby preventing ghost image formation while maintaining precise thickness control
2Reliability
If a supply roller is used to scrape residual toner, then developing hysteresis is suppressed, but toner deterioration accelerates due to mechanical stress
Solution Approach 1:
The invention replaces the mechanical scraping action of a supply roller with an electrostatic regulating mechanism. The curved contact surface of the regulating member controls toner layer thickness through regulated contact during the development process itself, eliminating the need for separate toner scraping operations that cause mechanical stress and toner deterioration
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 stabilizes image formation over time by preventing developing hysteresis, reducing ghost image occurrences, and maintaining image quality without accelerating toner deterioration.
Implementation Method 1
a contact curved surface having a concave curved surface that is provided approximately along a peripheral surface of the developer carrying member
Implementation Method 2
a developing roller (elastic roller) carrying toner and contacting the surface of a photosensitive drum
Implementation Method 3
The supply roller transports toner from the developer container and adheres the toner to the developing roller
Implementation Method 4
charge the toner layer by triboelectric charging
Data Source
AI summary
A developing apparatus includes a developer carrying member, a developer container, and a regulating member to regulate the thickness of the developer. The regulating member includes a support member having one end fixed to the developer container and the other end free, with the support member extending in a direction opposite to the rotating direction of the developer carrying member, and a contact member to be fixed to the other end of the support member and to contact the developer carrying member. The contact member includes a contact curved surface along a peripheral surface of the developer carrying member, and an opposite surface to face the developer carrying member. The contact pressure of the contact curved surface applied to the developer carrying member decreases as a location on the developer carrying member approaches a downstream side in the rotating direction.