Collecting Roller Axial Roughness Gradient for Toner Scraping

Solution Overview

Problem

Conventional cleaning devices for image forming apparatuses face challenges in effectively collecting toner residue due to issues with surface roughness of the collecting roller and toner sphericity, leading to clogging and deteriorated scraping properties, as well as potential blade turning-up and failures.

Innovation Solution

The cleaning device features a collecting roller with varying surface roughness along its axial direction, with lower roughness at the central part and higher roughness at the ends, and is made of a metal material with a high electrical resistance surface layer, ensuring efficient toner collection and preventing blade turning-up, regardless of toner sphericity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the surface roughness of the collecting roller is lowered to improve scraping property, then the scraping property of the cleaning blade is improved, but clogging of residue between the collecting roller and sealing member occurs

Engineering Contradiction:

Improvescraping propertyVSAvoidclogging prevention

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The collecting roller is designed with different surface roughness values at different locations: the central portion has a first surface roughness value (lower) to maintain good scraping property with the cleaning blade, while the both-end portions have a second surface roughness value (higher) to prevent clogging of residue with the sealing member. This local differentiation resolves the contradiction by optimizing each region for its specific function.

Inventive Principle:

Principle #3Local quality

2Reliability

If the surface roughness of the collecting roller is raised to prevent clogging, then clogging of residue is prevented, but scraping property by the cleaning blade is deteriorated

Engineering Contradiction:

Improveclogging preventionVSAvoidscraping property

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The collecting roller is designed with different surface roughness values at different locations: the central portion has a first surface roughness value (lower) to maintain good scraping property with the cleaning blade, while the both-end portions have a second surface roughness value (higher) to prevent clogging of residue with the sealing member. This local differentiation resolves the contradiction by optimizing each region for its specific function.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If the surface roughness of the collecting roller is extremely lowered to improve scraping property regardless of toner sphericity, then scraping property is improved, but close contact property increases causing blade turning-up and failures

Engineering Contradiction:

Improvescraping propertyVSAvoidblade stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The collecting roller is designed with different surface roughness values at different locations: the central portion has a first surface roughness value (lower) to maintain good scraping property with the cleaning blade, while the both-end portions have a second surface roughness value (higher) to prevent clogging of residue with the sealing member. This local differentiation resolves the contradiction by optimizing each region for its specific function.

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 configuration maintains excellent scraping properties and prevents blade turning-up, ensuring stable cleaning performance across different toner sphericity conditions and enhancing the collection of toner and sheet powder.

Implementation Method 1

The cleaning member is disposed to be rotatable while being in contact with a surface of an image carrier

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

it is necessary to construct the cleaning device in consideration of parameters, such as a material and surface roughness of the collecting roller, as well as an electrostatic friction coefficient of the sealing member

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 3

the collecting roller is made of a metal material with a high electrical resistance surface layer, ensuring efficient toner collection

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 4

the cleaning blade is disposed while being in contact with the collecting roller in a counter direction with respect to rotation of the collecting roller

Methodology Applied

Scientific EffectMechanical force: Mechanical Force

Data Source

PatentUS9772583B2Cleaning device and image forming apparatus

Publication Date: 2017.09.26 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A cleaning device includes a cleaning member, a collecting roller and a cleaning blade. The cleaning member is disposed to be rotatable while being in contact with a surface of an image carrier configured to carry a toner image to the surface. The collecting roller is disposed to be rotatable while being in contact with the cleaning member at a downstream side from the image carrier in a rotation direction of the cleaning member. The cleaning blade is disposed while being in contact with the collecting roller in a counter direction with respect to rotation of the collecting roller at a downstream side from the cleaning member in a rotation direction of the collecting roller. The collecting roller is formed so as to have larger surface roughness at an end than that at a central part in an axial direction.