Non-Contact Lubricant Application for Photosensitive Drum Uniformity

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Solution Overview

Problem

Image forming apparatuses using electrophotography face challenges in maintaining uniform lubricant application to extend the service life of photosensitive drums, leading to potential image defects like vertical stripe-like defects during printing due to uneven lubricant distribution and abrasion.

Innovation Solution

A lubricant application device featuring a grinding roller and a scattering member, such as a rod-shaped or perforated member, that pulverizes and scatters fine lubricant particles uniformly onto the photosensitive drum, preventing deposition and ensuring consistent lubrication, with optional conductive components and voltage application for enhanced distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lubricant application device uses contact-based application method, then lubricant can be applied to the photosensitive drum, but uneven lubricant distribution occurs leading to vertical stripe-like defects

Engineering Contradiction:

Improveprint qualityVSAvoidlubricant distribution uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical contact-based lubricant application system with a non-contact electrostatic application system. The charging roller applies electrostatic charge to the lubricant particles, and the photosensitive drum receives the charged lubricant without direct mechanical contact, eliminating the stripe-like defects caused by contact-based application while ensuring uniform distribution.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses a charging roller that rotates in contact with the lubricant supply to pick up lubricant particles through electrostatic charging. This mechanism allows the lubricant to be transferred to the photosensitive drum in a controlled, uniform manner without the mechanical pressure and uneven contact that cause striping in traditional systems.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If the grinding roller contacts the photosensitive drum directly, then lubricant application is effective, but the photosensitive drum surface is damaged increasing abrasion rate

Engineering Contradiction:

Improveservice lifeVSAvoidabrasion rate

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates direct mechanical contact between the grinding roller and the photosensitive drum by using electrostatic charging. The charging roller picks up lubricant particles through electrostatic attraction and transfers them to the drum surface without mechanical pressure, thereby preventing surface damage and reducing abrasion rate while maintaining effective lubrication.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Duration of action of stationary object

If conventional lubricant application methods are used, then lubricant is applied to extend service life, but image defects occur due to uneven distribution

Engineering Contradiction:

Improveservice lifeVSAvoidimage quality

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent replaces conventional mechanical lubricant application with an electrostatic non-contact system. The charging roller electrostatically charges lubricant particles and transfers them uniformly to the photosensitive drum, ensuring even distribution that prevents image defects while extending service life through consistent lubrication.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution effectively prevents image defects by ensuring uniform lubricant application, reducing abrasion rates, and maintaining low friction on the photosensitive drum, thus extending its service life and improving print quality.

Implementation Method 1

a scattering member disposed to contact the grinding roller at an outer periphery thereof, to scatter the carried lubricant toward a separate rotating member

Methodology Applied

Scientific EffectScattering: Scattering

Implementation Method 2

a grinding roller to carry, upon rotation, a lubricant scraped off from a solid lubricant source

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 3

with optional conductive components and voltage application for enhanced distribution

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentUS11454916B2Lubricant application device for non-contact applying of lubricant

Publication Date: 2022.09.27 HEWLETT PACKARD DEVELOPMENT COMPANY LP

AI summary

A lubricant application device for an image forming apparatus includes a grinding roller that is rotatable to scrape off a lubricant from a solid lubricant source, and a scattering member to scatter the lubricant from the grinding roller toward a separate rotating member.