Airflow Regulator Prevents Air Leakage in Pneumatic Developer Delivery

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Solution Overview

Problem

Conventional two-component developing systems face issues with air leakage in pneumatic paths, leading to insufficient mixing and delivery of developers, resulting in reduced print quality due to variations in toner concentration and electrical charge distribution.

Innovation Solution

An image forming apparatus with a developing system that includes a rotary feeder, an air pump, and an airflow regulator to prevent compressed air from leaking into the mixing container, ensuring reliable and efficient delivery of developers by using a configuration where the airflow regulator obstructs air flow at the junction zone between the rotary feeder and the delivery path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a pneumatic path is used to deliver developer from mixing container to development unit, then delivery efficiency is improved, but air leakage occurs at the dispensing opening causing reduction in propelling pressure and delivery performance

Engineering Contradiction:
Improvedelivery efficiencyVSAvoiddelivery performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A flexible membrane is provided at the dispensing opening of the measuring feeder to seal the opening when compressed air is flowing through the delivery tube. The membrane is flexible enough to allow developer passage when not pressurized, but forms a seal when air pressure is applied, preventing air leakage while maintaining delivery efficiency.

Inventive Principle:
Principle #30Flexible shells and thin films

2Speed

If compressed air is used to propel developer through delivery tube, then delivery speed is improved, but air leakage causes loss of propelling pressure and insufficient delivery

Engineering Contradiction:
Improvedelivery speedVSAvoidpropelling pressure
Core Design Contradiction:
SpeedVSStress or pressure

Solution Approach 1:

The flexible membrane seals the dispensing opening during compressed air flow, preventing air leakage that would cause propelling pressure loss. This maintains the pressure necessary for high-speed delivery while allowing rapid developer transport through the delivery tube.

Inventive Principle:
Principle #30Flexible shells and thin films

3Measurement precision

If measuring feeder dispenses developer at the connection point, then delivery precision is improved, but compressed air leakage into mixing container obstructs developer flow and varies dispensing rate

Engineering Contradiction:
Improvedispensing precisionVSAvoiddispensing rate
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The membrane seals the dispensing opening when compressed air is flowing, preventing air from entering the mixing container. This obstruction prevention ensures consistent developer flow from the mixing container to the measuring feeder, maintaining stable dispensing rates and precise measurement.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If rotor blades are formed of resilient material to fit tightly in stator for sealing, then sealing performance is improved, but rubbing against stator wall causes degradation of metering mechanism

Engineering Contradiction:
Improvesealing performanceVSAvoiddurability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

A flexible membrane is used instead of resilient rotor blades to achieve sealing. The membrane provides the necessary seal at the dispensing opening without contact friction against the stator wall, eliminating wear and degradation while maintaining sealing performance during compressed air flow.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible membrane acts as an intermediary sealing element that provides the seal function without the mechanical contact and friction that would degrade the metering mechanism. It mediates between the need for sealing and the need for durability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2031459B1Image forming apparatus and developing system incorporated therein
Publication Date: 2012.04.25 RICOH CO LTD
  • EP2031459B1 patent drawingFigure 1
  • EP2031459B1 patent drawingFigure 2A~2B
  • EP2031459B1 patent drawingFigure 3A~3B

AI summary

An image forming apparatus includes an electrophotographic system and a developing system (50). The electrophotographic system forms an electrostatic latent image. The developing system develops the electrostatic latent image, and includes a developing unit, a mixing container (51), a rotary feeder (53), an air pump (54), and an airflow regulator (80). The mixing container (51) is separated from the developing unit and holds and mixes part of the developer after use. The rotary feeder (53) dispenses the developer from the mixing container (51) to a delivery path (56,58,77). The air pump (54) supplies compressed air to deliver the dispensed developer to the developing unit through the delivery path (56,58,77). The airflow regulator (80) is located where the rotary feeder (53) connects to the delivery path (56,58,77), and hinders the compressed air from flowing toward the rotary feeder (53) from the delivery path (56,58,77).