Skeleton Watch Case Back Coating for Movement Visibility Privacy

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Solution Overview

Problem

Skeleton watches with transparent case backs often reveal the wearer's wrist, detracting from the aesthetic appeal and compromising privacy.

Innovation Solution

A skeleton watch with a semi-transparent coating on the case back that conceals the support when worn and reveals the movement when not in use, using materials like chromium, titanium, or aluminum, and optionally a transparent protective layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the case back is made transparent to showcase the movement, then the aesthetic appeal and visibility of the movement is improved, but the wearer's wrist becomes visible which compromises privacy and aesthetics

Engineering Contradiction:
Improvevisibility of movementVSAvoidwrist visibility
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies a dynamic solution by using an electrochromic coating that can change its transparency state. The case back transitions from transparent to opaque based on electrical signals, allowing the watch to adapt between showcasing the movement and concealing the wrist as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electrochromic coating changes its optical parameters (transparency/opacity) in response to electrical voltage changes. By adjusting the electrical parameter, the case back can switch between transparent and opaque states, resolving the contradiction between visibility and privacy.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If a semi-transparent coating is applied to the case back to conceal the wrist, then privacy and aesthetic integrity is improved, but the visibility of the movement from the back is reduced

Engineering Contradiction:
Improvewrist concealmentVSAvoidmovement visibility
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The electrochromic coating provides dynamic control over transparency. When voltage is applied, the coating becomes transparent allowing movement visibility; when voltage is removed, it becomes opaque to conceal the wrist. This dynamic switching resolves the contradiction between concealment and visibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The optical parameters of the coating are changed through electrical control. The coating transitions between transparent and opaque states based on electrical parameters, enabling the system to achieve both wrist concealment and movement visibility at different times as needed.

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

Maintains the aesthetic integrity and privacy by hiding the support while showcasing the movement from the back, enhancing the visual experience.

Implementation Method 1

The coating is an electrochromic material coating

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Data Source

PatentEP3828645B1Skeleton watch
Publication Date: 2025.11.12 MONTRES BREGUET SA
  • EP3828645B1 patent drawingFigure 1~3

AI summary

The present invention relates to a skeleton watch designed to be placed on a stand. The watch comprises a case with a transparent back and a crystal, and a set of components forming a movement of the skeleton watch. These components are arranged within the case between the back and the crystal and are wholly or partially visible through the crystal. According to the invention, the back comprises a semi-transparent coating arranged to conceal the stand when the watch is on it and to make the movement visible through the back when the watch is not on the stand.