Watch Dial Recess Geometry for Uniform Surface Brightness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing watch dials with laser-processed grooves struggle to enhance brightness uniformly across the surface, as the brightness of areas without grooves remains unchanged, limiting design and decorative options.

Innovation Solution

A watch component featuring a substrate with recesses formed such that their depth is 55 µm or less, pitch is 65 µm or more, and tangent inclination is 70° or less, which scatters incident light to increase brightness uniformly across the surface, combined with a multilayer film for enhanced color and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the pitch between recesses is reduced to increase surface coverage, then the light scattering effect is improved, but the manufacturing precision and uniformity of recess formation deteriorates

Engineering Contradiction:
Improvelight scattering effectVSAvoiduniformity of recess formation
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent optimizes the pitch parameter to 65μm or more, establishing a minimum spacing that balances light scattering effectiveness with manufacturing feasibility. This parameter setting ensures sufficient surface coverage for light diffusion while maintaining the precision required for uniform recess formation through laser processing.

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 solution achieves a higher average brightness value across a wider range of viewing angles, allowing for a greater variety of brightness expression and improved decorative and design properties, while the multilayer film extends color tones and enhances appearance stability.

Implementation Method 1

the plurality of recesses 32 scatter incident light, so that an average value of brightness L* as viewed from a wide range of viewing angles is made higher

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP4428629A1Watch component, watch, and method for manufacturing watch component
Publication Date: 2024.09.11 SEIKO EPSON CORP
  • EP4428629A1 patent drawingFigure 1
  • EP4428629A1 patent drawingFigure 2
  • EP4428629A1 patent drawingFigure 3

AI summary

A watch component includes a substrate having a surface on which a plurality of recesses are formed, wherein in a cross-sectional view obtained by cutting the substrate in a thickness direction, a depth of the recesses along the thickness direction is 55 µm or less, and a pitch which is a length between bottom portions of adjacent ones of the recesses is 65 µm or more.