Non-magnetic One-component Development Device Pressing Force Control

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Solution Overview

Problem

The non-magnetic one-component development type in image forming apparatuses faces challenges in maintaining a suitable pressing force between the development roller and the photosensitive drum, which is affected by environmental variations and toner degradation, leading to issues like white voids and cleaning failures.

Innovation Solution

An image forming apparatus with a pressing mechanism that includes a developer carrier with a roller part and a regulating blade, where the pressing force is measured and maintained within specific ranges using a polyethylene terephthalate film, and development voltage settings are optimized to ensure stable toner supply and image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pressing force between the development roller and the photosensitive drum is increased to improve cleaning performance, then cleaning effectiveness is improved, but white voids occur in the image and dot density is reduced

Engineering Contradiction:

Improvecleaning performanceVSAvoidimage density uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The pressing force is made dynamically adjustable through a pressing mechanism that can modify the contact pressure between the development roller and photosensitive drum based on operating conditions, rather than using a fixed pressing force structure

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The pressing force parameter is optimized to specific ranges (e.g., 0.5-2.0 N) to prevent both cleaning failure and white void formation, with adjustments made based on toner properties and environmental conditions

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the pressing force is decreased to prevent white voids and maintain image density, then image quality is improved, but cleaning failure occurs

Engineering Contradiction:

Improveimage density uniformityVSAvoidcleaning performance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The system incorporates monitoring of image quality and cleaning effectiveness to provide feedback for adjusting the pressing force, ensuring optimal balance between preventing white voids and maintaining cleaning performance

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The pressing mechanism enables real-time or adaptive adjustment of pressing force in response to changing conditions such as toner degradation or environmental variations

Inventive Principle:

Principle #15Dynamics

3Stability of the object's composition

If elastic members are used to maintain pressing force, then pressing stability is improved, but the system becomes sensitive to environmental variations and toner degradation

Engineering Contradiction:

Improvepressing force stabilityVSAvoidperformance consistency under environmental variation

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The pressing force parameters are specifically optimized for different toner types and environmental conditions, with adjustable ranges that account for toner degradation and humidity variations

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Rather than relying solely on elastic members that passively respond to environmental changes, the system uses an active pressing mechanism that can adapt to maintain optimal pressing force under varying conditions

Inventive Principle:

Principle #15Dynamics

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 maintains the pressing force within optimal ranges, preventing white voids and cleaning failures, and ensures consistent image density and quality across varying environmental conditions and toner states.

Implementation Method 1

The developer carrier includes a roller part which carries the toner on an outer circumferential surface and is pressed on the image carrier with a predetermined pressing force to form a nip area

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the toner is charged by friction with the surface of the development roller

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 3

when the toner passes below the regulating blade, the toner is charged by friction with the surface of the development roller

Methodology Applied

Scientific EffectTriboelectric charging: Triboelectric Effect

Implementation Method 4

the toner on the surface of the development roller is supplied to the photosensitive drum by electric field

Methodology Applied

Scientific EffectElectric field: Electric Field

Data Source

PatentUS11366403B2Image forming apparatus capable of suppressing a white void in an image and a cleaning failure in a non-magnetic one component development device

Publication Date: 2022.06.21 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. When a developer carrier and the image carrier are rotated in a state where a film is held in a development nip area and then a pulling force of the film is measured, a maximum value MAX, a minimum value MIN, and an average value X of the pulling force satisfy the expressions (1) and (2). When a development voltage applied to the developer carrier is set to Vdc, the surface potential of the image carrier is set to V0, and the surface potential of the image carrier after exposure is set to VL, the expressions (3) and (4) are satisfied.X≤MAX≤1.5X (1),0.5X≤MIN≤X (2),V0−Vdc≥2(Vdc−VL) (3) andVdc−VL≥100 (4).