Developer Carrying Device Pressing Wall for Toner Sensor Accuracy

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Solution Overview

Problem

Conventional toner-concentration detecting units in developer carrying devices are prone to erroneous detection due to environmental fluctuations and electric charge variations, leading to misinterpretation of toner concentration changes, despite the toner concentration remaining unchanged.

Innovation Solution

The implementation of a developer carrying device with a pressing mechanism that applies a controlled force to the developer in the detection area, utilizing a reverse carrying blade and a pressing wall to ensure consistent contact with the toner concentration sensor, thereby reducing misdetected toner concentration fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the developer is pressed strongly in the detection position to adjust the amount of toner affecting concentration detection, then the detection reliability is improved, but the device complexity increases due to additional pressing mechanisms

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressing wall is positioned specifically at the detection position to apply localized pressure only where needed for accurate measurement. This local pressing action ensures consistent developer contact with the concentration sensor without requiring system-wide pressing mechanisms, thus improving detection reliability while minimizing added complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The pressing wall acts as an intermediary element between the developer flow and the detection system. It mediates the interaction by providing controlled pressure at the detection interface, ensuring reliable toner concentration measurements without directly modifying the overall developer carrying mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If environmental fluctuation or electric charge variation occurs, then the measurement precision deteriorates due to erroneous detection, but adding pressing mechanisms increases device complexity

Engineering Contradiction:
Improvetoner concentration measurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pressing wall provides localized pressure control at the detection position, ensuring that the developer maintains consistent contact with the concentration sensor. This local intervention compensates for environmental fluctuations and electric charge variations without requiring complex system-wide adjustments, thereby improving measurement precision with minimal added complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The pressing mechanism changes the physical state of the developer at the detection position by applying controlled pressure. This parameter change (pressure application) stabilizes the developer's physical properties during measurement, reducing erroneous detection caused by environmental fluctuations and charge variations while maintaining simple device architecture.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the developer volume changes due to environmental fluctuation, then the detection accuracy deteriorates, but strong pressing to compensate increases device complexity

Engineering Contradiction:
Improvedetection accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pressing wall is strategically positioned at the detection location to apply pressure only where volume changes affect measurement accuracy. This localized pressing compensates for developer volume variations caused by environmental fluctuations without requiring complex overall system modification, thus improving detection accuracy while keeping device complexity low.

Inventive Principle:
Principle #3Local quality

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 solution effectively minimizes misdetected toner concentration readings by ensuring consistent developer contact with the sensor, maintaining accurate toner concentration control and preventing toner density fluctuations.

Implementation Method 1

a permeability sensor that detects a toner concentration of the developer passing through the sensor in a rotation radial direction

Methodology Applied
Scientific EffectPermeability measurement: Permeation

Data Source

PatentEP2054775B1Developer carrying device, developing device, process unit, and image forming apparatus
Publication Date: 2020.06.17 RICOH CO LTD
  • EP2054775B1 patent drawingFigure 1~2
  • EP2054775B1 patent drawingFigure 3~4
  • EP2054775B1 patent drawingFigure 5

AI summary

A pressing wall is provided in a part of the entire area of the first carrying chamber in which a first screw member is housed. The area is opposed to a bottom wall of the first carrying chamber on the lower side in the gravity direction of the first screw member and opposed to the side walls of the first carrying chamber on both lateral sides orthogonal to a rotation axis direction of the first screw member. In the area, a toner concentration of a K developer being carried is detected by a K toner concentration sensor. The pressing wall comes into contact with, from above in the gravity direction, the K developer, which moves from a lower side to an upper side in the gravity direction according to the rotation of the first screw member, and presses the K developer downward in the gravity direction.