Rotor-Integrated Watch Microgenerator for Battery-Free Lighting

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Solution Overview

Problem

Existing mechanical watches with lighting systems compromise the mechanical character by incorporating electronic and electrical components that occupy a large surface area and extend beyond the rotor, creating a hybrid appearance.

Innovation Solution

A micro-generator with a rotor carrying coils and light-emitting diodes, powered directly by the coils, and a stator with permanent magnets, where all electrical and electronic components are integrated onto the rotor, eliminating the need for external wiring and PCBs, and a stationary light guide structure to distribute light uniformly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If lighting systems are provided with electroluminescent elements, electronic circuits and electrical circuits arranged on a fixed support at the periphery of the rotor, then lighting function is achieved, but the mechanical character of the watch is compromised and surface area is increased

Engineering Contradiction:
Improvelighting functionVSAvoidmechanical character
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges the lighting function directly into the rotor assembly by integrating electroluminescent elements and electrical circuits onto the rotor itself, rather than placing them on a separate fixed support. This consolidation eliminates the need for external wiring and reduces the overall device complexity while maintaining the lighting function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention transitions from a two-dimensional arrangement where lighting components are placed on the periphery of the rotor to a three-dimensional integration where components are embedded within the rotor structure itself. This dimensional reorganization reduces the surface area occupied by lighting components and preserves the mechanical aesthetic.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If lighting components are arranged on a fixed support at the periphery of the rotor, then lighting is provided, but the surface area beyond the rotor surface is extended

Engineering Contradiction:
Improvelighting functionVSAvoidsurface area
Core Design Contradiction:
Illumination intensityVSArea of stationary object

Solution Approach 1:

The patent nests the lighting components (electroluminescent elements and electrical circuits) within the rotor structure itself, rather than placing them on an external fixed support. This nesting approach allows the lighting function to be achieved while keeping the overall surface area occupied by the timepiece compact and aesthetically pleasing.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Illumination intensity

If stationary electrical and electronic parts are arranged on a fixed support, then lighting function is achieved, but the hybrid character of the watch is accentuated

Engineering Contradiction:
Improvelighting functionVSAvoidhybrid character
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent combines the lighting function directly into the rotor assembly by integrating electroluminescent elements and electrical circuits onto the rotor itself, rather than placing them on a separate fixed support. This consolidation eliminates the need for external wiring and reduces the overall device complexity while maintaining the lighting function.

Inventive Principle:
Principle #5Merging (Combining)

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 maintains the mechanical integrity of high-end watches by integrating discreet, high-speed lighting that appears continuous and uniform, compatible with skeleton constructions and allowing on-demand operation without batteries or capacitors.

Implementation Method 1

a micro-generator comprising a rotor, carrying at least one coil and at least one light-emitting diode powered by at least one said coil during its rotation relative to the stator of the micro-generator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a stator comprising permanent magnets

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Data Source

PatentEP4443247B1Timepiece comprising a microgenerator and a light source
Publication Date: 2025.08.20 THE SWATCH GRP RES & DEVELONMENT LTD
  • EP4443247B1 patent drawingFigure 1
  • EP4443247B1 patent drawingFigure 2A~2B
  • EP4443247B1 patent drawingFigure 3~4

AI summary

One aspect of the invention relates to a timepiece comprising a micro-generator (100), formed of a stator (20) having permanent magnets (25) and a rotor (10) having coils (11) and at least one light-emitting diode (31, 32), which is powered, directly or indirectly through an electrical and/or electronic circuit, by at least one of the coils that provides an induced electric current during its rotation relative to the stator (20). The rotor carries all the electrical and electronic equipment formed by said at least one light-emitting diode, the coils and, where applicable, said electrical and/or electronic circuit.