Fixing Belt Surface Roughness Control for Image Quality
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Solution Overview
Problem
The existing fixing systems in electrophotography face issues with image defects such as poor mirror surface properties and white-spot defects due to the surface characteristics of the fixing belt, which affect the quality of the images formed on recording media.
Innovation Solution
A fixing method and apparatus where the recording medium is conveyed in contact with a fixing belt having a surface roughness of 0.7 μm or less in ten-point average roughness (Rz) and filtered maximum waviness of 50 μm or less, to prevent defects by ensuring a smooth and even surface for toner image solidification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixing belt with conventional surface roughness is used, then the fixing function is achieved, but image defects such as poor mirror surface properties and white-spot defects occur
Solution Approach 1:
The patent applies parameter changes by precisely controlling the surface roughness of the fixing belt to Rz ≤ 0.7 μm and filtered maximum waviness to 50 μm or less. This parameter optimization resolves the technical contradiction by ensuring that the fixing belt surface characteristics do not impart defects to the toner image while maintaining effective fixing functionality.
2Strength
If a metal substrate is used for the fixing belt, then structural strength is improved, but operator safety deteriorates due to hot edges and handling becomes inconvenient
Solution Approach 1:
The patent employs composite materials by combining a metal substrate (providing structural strength) with a heat-resistant resin coating layer (providing safety and ease of handling). This composite structure resolves the contradiction by integrating the advantages of both materials while eliminating their respective disadvantages.
Solution Approach 2:
The patent uses a heat-resistant resin coating layer as a thin film covering the metal substrate. This flexible coating provides a safe, non-hot surface for handling while the underlying metal substrate maintains the structural strength required for the fixing function.
3Object-affected harmful factors
If a heat-resistant resin belt is used, then operator safety is improved, but the surface state causes image defects such as orange peel effect and white-spot defects
Solution Approach 1:
The patent applies parameter changes by precisely controlling the surface roughness of the fixing belt to Rz ≤ 0.7 μm and filtered maximum waviness to 50 μm or less. This parameter optimization resolves the technical contradiction by ensuring that the fixing belt surface characteristics do not impart defects to the toner image while maintaining effective fixing functionality.
Solution Approach 2:
The patent applies preliminary action by performing surface treatment on the heat-resistant resin belt before it contacts the toner image. The surface is treated to achieve the required roughness specifications, preventing image defects before they can occur during the fixing process.
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 suppresses the generation of image defects, resulting in improved mirror surface properties and reduced white-spot defects, enhancing the overall image quality.
Implementation Method 1
a fixing portion that heats and presses a recording medium having a toner image formed thereon
Implementation Method 2
a cooling portion that cools the recording medium after the recording medium has passed through the fixing portion
Data Source
AI summary
The invention provides a fixing method including conveying a recording medium on which a toner image has been formed using a fixing belt, in a state in which the fixing belt contacts with a surface of the recording medium on which the toner image is formed, at least from a fixing portion in which the toner image is fixed by heating and pressing the recording medium to a cooling portion in which the recording medium after fixing is cooled, wherein the ten-point average roughness (Rz) of a surface of the fixing belt contacting with the recording medium is 0.7 μm or less or the filtered maximum waviness in every convex portion present on a surface of the fixing belt contacting with the recording medium is 50 μm or less. The invention also provides a fixing apparatus using the method and an image forming apparatus using the method.