Developing Device Toner Particle Size Control
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Solution Overview
Problem
The existing developing devices with multiple rollers face the challenge of sleeve memory, where toner unevenness leads to optical density variations in images, due to stress applied during layer thickness regulation and scraping, which affects developing efficiency and image quality.
Innovation Solution
A developing device with an upstream and downstream developing roller system, where the toner in the developer handed over from the upstream roller to the downstream roller has a larger volume average particle size, and a bias voltage composed of DC and AC biases is applied to ensure proper toner adhesion and distribution, minimizing stress on the toner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If layer thickness regulation and scraping are applied to prevent sleeve memory, then toner distribution uniformity is improved, but stress on toner increases which reduces developing efficiency
Solution Approach 1:
The invention changes the particle size parameter of toner by controlling the development process parameters (bias voltage, developing roller speed, developer composition) to produce toner with larger average particle size that adheres more uniformly to the photoreceptor without requiring mechanical scraping, thus preventing sleeve memory while maintaining developing efficiency
2Productivity
If multiple developing rollers are used to increase developing efficiency, then image formation speed is improved, but sleeve memory occurs due to toner adhesion variations
Solution Approach 1:
The invention adjusts the particle size parameter of toner and the electric field parameters (bias voltage composition) to control toner adhesion behavior, ensuring uniform toner distribution across multiple developing rollers and preventing sleeve memory while maintaining high image formation speed
Solution Approach 2:
The invention replaces mechanical layer thickness regulation and scraping mechanisms with an electric field-based control system that uses bias voltage to regulate toner adhesion, eliminating mechanical stress on toner while preventing sleeve memory in multi-roller systems
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 approach effectively prevents sleeve memory by ensuring uniform toner distribution and adhesion, maintaining high developing efficiency and image quality without increasing stress on the toner, thus achieving consistent optical density across images.
Implementation Method 1
develops the latent image carried by the photoreceptor by making toner particles in the developer to adhere the latent image under a bias voltage composed of a DC bias and an AC bias
Data Source
AI summary
A developing device, includes a developer agitating member, an upstream side developing roller, and a downstream side developing roller; wherein a toner in a developer handed over from the upstream side developing roller to the downstream side developing roller has a volume average particle size larger than a volume average particle size of the toner in the developer conveyed by the upstream side developing roller to the facing position between the upstream side developing roller and a photoreceptor drum.