Laser Satin Timepiece Component for Scratch-Resistant Handling

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Solution Overview

Problem

Existing timepiece components with satin patterns formed by blast processing are prone to noticeable scratches when handled with tweezers due to the crushing of protrusions, leading to degradation in design and assembly issues.

Innovation Solution

A timepiece component with a satin pattern formed by laser processing, where the average length RSm of the roughness curve is 40 µm to 135 µm and skewness Rsk is -3.1 to 0, minimizing protrusion crushing and enhancing the satin pattern's aesthetic appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If blast processing is used to form a satin pattern, then the processing method is simple and cost-effective, but the protrusions are crushed when held with tweezers causing noticeable scratches

Engineering Contradiction:
Improveprocessing method simplicityVSAvoidnoticeable scratches
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the surface roughness parameters by controlling the average length RSm (40-135 μm) and skewness Rsk (-3.1 to 0) of the satin pattern. This parameter optimization ensures that protrusions are not too sharp or prominent, thereby reducing noticeable scratches when the component is handled with tweezers while maintaining the aesthetic satin appearance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical blast processing method with a different surface treatment approach that achieves the desired satin pattern with controlled roughness characteristics. This substitution allows for precise control over the surface topology, creating a pattern that resists showing scratches during handling.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Shape

If the satin pattern has prominent protrusions, then the aesthetic appearance is enhanced, but the protrusions become noticeable as scratches when held with tweezers

Engineering Contradiction:
Improvesatin pattern appearanceVSAvoidnoticeable scratches
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent optimizes the skewness Rsk parameter to be between -3.1 and 0, which controls the shape characteristics of the surface protrusions. This parameter control creates a satin pattern with sufficient aesthetic appearance while ensuring protrusions are not overly sharp or prominent, thereby minimizing noticeable scratches during handling.

Inventive Principle:
Principle #35Parameter changes

3Shape

If the roughness curve average length RSm is increased, then the satin pattern becomes more pronounced, but the protrusions are more likely to be crushed and show as scratches

Engineering Contradiction:
Improvesatin pattern prominenceVSAvoidprotrusion crushing
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent establishes an optimal range for the average length RSm parameter (40-135 μm) that balances two competing requirements: creating a sufficiently pronounced satin pattern for aesthetic purposes while limiting the size and sharpness of protrusions to prevent them from being crushed and showing as noticeable scratches during handling.

Inventive Principle:
Principle #35Parameter changes

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 laser-processed satin pattern reduces noticeable scratches and maintains the design integrity of the timepiece component, allowing for easier handling and improved assembly efficiency.

Implementation Method 1

irradiating a base with a laser, and forming a satin pattern in a processing region of the base

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4650092A1Timepiece component and method for manufacturing timepiece component
Publication Date: 2025.11.19 SEIKO EPSON CORP
  • EP4650092A1 patent drawingFigure 1
  • EP4650092A1 patent drawingFigure 2
  • EP4650092A1 patent drawingFigure 3

AI summary

A timepiece component has a satin pattern formed. An average value of an average length RSm of a roughness curve of a surface of the satin pattern is 40 µm or more and 135 µm or less. An average value of a skewness Rsk of the roughness curve is - 3.1 or more and 0 or less.