Non-rotary Pad Fixing Apparatus with Edge Pressure Guide

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Solution Overview

Problem

In pad-fixing systems for image forming apparatuses, lubricant leakage from the belt edge leads to increased frictional resistance and accelerated wear, hindering smooth operation and sheet conveyance due to uneven lubricant distribution and pressure within the fixing nip.

Innovation Solution

A fixing apparatus with a non-rotary pad and a guide that applies pressure to the belt's edge upstream of the fixing nip, with pressure decreasing from the edge towards the center, to guide the lubricant into the nip formation area and prevent leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a lubricant is applied on the inner peripheral surface of the belt to reduce frictional resistance, then frictional resistance between the belt and fixed pad is reduced, but the lubricant leaks from the belt edge causing reduced lubricant amount and increased frictional resistance

Engineering Contradiction:

Improvefrictional resistanceVSAvoidlubricant distribution stability

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The invention divides the belt width direction into multiple regions by introducing guide parts that create separate pathways for lubricant flow. The guide parts segment the lubricant distribution pattern, directing lubricant toward the center region and preventing it from reaching the edges where it would leak, thus solving the contradiction between reducing friction and maintaining lubricant stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The guide parts act as intermediary structures between the lubricant source and the belt surface. These guide parts mediate the lubricant flow by channeling it along the belt inner peripheral surface toward the center, preventing direct leakage at the edges while ensuring adequate lubrication of the contact region between belt and fixed pad.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stress or pressure

If pressure is applied uniformly across the belt width, then the fixing nip pressure is maintained, but lubricant cannot be effectively guided into the nip formation area and leaks from the edges

Engineering Contradiction:

Improvefixing nip pressureVSAvoidlubricant leakage

Core Design Contradiction:

Stress or pressureVSLoss of substance

Solution Approach 1:

The invention applies different pressure characteristics to different regions of the belt width direction. By introducing guide parts with specific geometric configurations, the system creates localized pressure variations that guide lubricant flow toward the center region. This local quality differentiation allows maintaining overall fixing nip pressure while preventing lubricant leakage from edges.

Inventive Principle:

Principle #3Local quality

3Productivity

If the belt circulates continuously, then sheet conveyance is maintained, but lubricant gradually flows toward the end side and leaks from the belt edge

Engineering Contradiction:

Improvesheet conveyance continuityVSAvoidlubricant amount on belt

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The guide parts are positioned upstream of the fixing nip to preliminarily guide and direct lubricant flow before the lubricant can reach the edges and leak. This preliminary action of channeling lubricant toward the center region prevents the gradual migration and leakage that would otherwise occur during continuous belt circulation, ensuring sustained lubricant quantity on the belt surface.

Inventive Principle:

Principle #10Preliminary action

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 lubricant within the belt, reducing frictional resistance and wear, ensuring smooth belt and roller rotation, and preventing sheet conveyance failures by stabilizing lubricant distribution and pressure within the fixing nip.

Implementation Method 1

a pressure application part that applies a pressure between an end of the belt in a belt width direction and the guide at a position that is upstream of and immediately before the fixing nip in the belt circulating direction, the pressure gradually decreasing from the end side toward a central side in the belt width direction

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

a lubricant is applied on an inner peripheral surface of the belt to reduce frictional resistance between the belt and the fixed pad

Methodology Applied

Scientific EffectLubrication: Lubrication

Data Source

PatentUS11774892B2Fixing apparatus containing non-rotary pad and pressure application part, and image forming apparatus containing same

Publication Date: 2023.10.03 KONICA MINOLTA INC

AI summary

Provided is a fixing apparatus that fixes an unfixed image on a sheet by causing the sheet to pass through a fixing nip formed by pressing a belt by a pressurizing roller, a lubricant being applied on an inner peripheral surface of the belt, the pressurizing roller being disposed on an outer peripheral side of the belt, and the fixing apparatus includes: a non-rotary pad including a pressed part disposed on an inner peripheral side of the belt and pressed by the pressurizing roller via the belt, and a guide that is disposed upstream of the pressed part in a belt circulating direction and guides the belt to the fixing nip; and a pressure application part that applies a pressure between an end of the belt in a belt width direction and the guide at a position upstream of and immediately before the fixing nip in the belt circulating direction.