Developing Device Air Flow Control for Toner Scattering

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Solution Overview

Problem

Existing developing devices in image forming apparatuses face challenges in managing air pressure and preventing toner scattering during the rotation of the developing sleeve, which affects the efficiency and reliability of the image formation process.

Innovation Solution

The developing device incorporates an inflow portion with an inflow port placed downstream of the supply region and an outflow portion with an outflow port, both adjacent to each other, to control air flow and maintain atmospheric pressure, utilizing a forming member to create a pressure gradient that reduces the risk of toner scattering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the developing sleeve rotates at high speed to increase image forming speed, then productivity is improved, but air pressure instability and toner scattering occur

Engineering Contradiction:

Improveimage forming speedVSAvoidair pressure stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The developing device is segmented into distinct functional regions: a supply region where developer is supplied to the image holding member, and a downstream region where air flow control is implemented. The inflow port and outflow port are positioned in different locations to create controlled air flow zones, allowing high-speed rotation while maintaining air pressure stability through regional functional differentiation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Air acts as an intermediary substance introduced through the inflow port to regulate pressure within the storage container. The air flow, controlled by the positioned inflow and outflow ports, mediates between the rotating developing sleeve and the stored developer, preventing toner scattering while enabling high-speed operation for improved productivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If filters are added to prevent toner scattering, then reliability is improved, but device complexity and size increase

Engineering Contradiction:

Improvetoner scattering preventionVSAvoiddevice structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the air flow control function from the traditional filter system. Instead of using physical filters to prevent toner scattering, the invention introduces controlled air flow through strategically positioned inflow and outflow ports, which naturally regulates pressure and prevents toner scattering without adding complex filtering components.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention employs pneumatic principles by introducing air flow through the inflow port and controlling pressure differential via the outflow port. This pneumatic approach replaces mechanical filter systems, maintaining toner scattering prevention through pressure control while reducing device complexity and avoiding additional filter components.

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Speed

If the inflow port is positioned upstream to improve air flow, then air flow efficiency is improved, but toner scattering increases due to pressure instability

Engineering Contradiction:

Improveair flow rateVSAvoidtoner scattering

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

Instead of positioning the inflow port upstream as conventionally expected for improved air flow, the invention inverts the approach by positioning the inflow port downstream of the supply region. This inverted positioning, combined with the outflow port placement, creates a pressure gradient that flows air through the storage container in a direction that maintains stability and prevents toner scattering while still achieving efficient air flow.

Inventive Principle:

Principle #13The other way round (Inversion)

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 effectively manages air pressure within the device, preventing toner scattering and ensuring consistent image formation, even at increased image forming speeds, while minimizing the need for additional filters and maintaining a compact device size.

Implementation Method 1

utilizing a forming member to create a pressure gradient that reduces the risk of toner scattering

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

an outflow portion that is provided with an outflow port and emits air in the storage container from the outflow port

Methodology Applied

Scientific EffectAir flow control: Convection

Data Source

PatentUS9244376B2Developing device

Publication Date: 2016.01.26 FUJIFILM BUSINESS INNOVATION CORP

AI summary

Provided is a developing device including a storage container that stores a developer, a rotating body that supplies the developer to an image holding member in a supply region by being rotated with holding the developer, an inflow portion that is provided with an inflow port placed on a downstream side of the supply region in a rotation direction of the rotating body, and flows air into the storage container, and an outflow portion that is provided with an outflow port and emits air in the storage container from the outflow port, wherein the outflow port and the inflow port are placed to be adjacent to each other.