Movable Indicator With Fluorescent Light Guide Eliminates Friction

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Solution Overview

Problem

Existing analog display devices, such as watches, face mechanical overload and energy loss due to frictional contacts between electrical components, leading to precision issues and uncontrolled wear.

Innovation Solution

A movable indicator with a multi-layer structure comprising an opaque metal layer and a transparent light guide layer, where fluorescent material absorbs and re-emits light flux without physical contact, eliminating the need for frictional contacts and allowing remote excitation of the light source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If friction contacts are used between drive shafts and battery terminals to provide power to light sources, then electrical power can be transmitted, but mechanical overload and energy loss occur due to friction

Engineering Contradiction:
Improveenergy lossVSAvoidmechanical overload
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent replaces the mechanical friction-based electrical contact system with a magnetic field-based wireless power transmission system. The battery contains a magnet that generates a magnetic field, which induces current in a coil within the indicator, eliminating the need for physical friction contacts and thereby reducing both mechanical overload and energy loss from friction

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

Solution Approach 2:

The patent introduces a magnetic field as an intermediary to transfer energy from the battery to the indicator. Instead of direct mechanical contact, the magnet in the battery creates a magnetic field that couples with the coil in the indicator, serving as a non-contact energy transmission medium that eliminates friction-related losses

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If friction contacts are used between drive shafts and battery terminals, then electrical connection is established, but precision is lost due to wear and mechanical interference

Engineering Contradiction:
ImproveprecisionVSAvoidwear of contacts
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The patent eliminates mechanical friction contacts entirely by using magnetic field-based wireless power transmission. The magnet in the battery and the coil in the indicator create an inductive coupling that transfers energy without physical contact, preventing wear and maintaining precision over time

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

Solution Approach 2:

The magnetic field acts as an intermediary that enables energy transfer without direct contact between moving parts. This eliminates the wear and precision loss associated with friction contacts while maintaining reliable power delivery to the light sources

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This solution reduces mechanical overload, minimizes energy loss, and enhances precision by eliminating frictional contacts while allowing for easy manufacturing and customizable color generation, maintaining aesthetic standards.

Implementation Method 1

A fluorescent material is arranged on the transparent light guide layer at the head of the indicator to absorb at least a portion of said luminous flux and to re-emit a second luminous flux of fluorescence into the transparent light guide layer

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3845974B1Mobile indicator for an analogue display device
Publication Date: 2024.02.21 THE SWATCH GRP RES & DEVELONMENT LTD
  • EP3845974B1 patent drawingFigure 1~3

AI summary

One aspect of the invention relates to a movable indicator for an analog display device, particularly for a timepiece. The indicator comprises a multi-layered component including an opaque metallic layer and a transparent light-guide layer, forming the body and head of the indicator. The head is centered about an axis of rotation of the indicator and arranged to receive a luminous flux on its underside. A fluorescent material is arranged on the transparent light-guide layer at the indicator head to absorb at least a portion of said luminous flux and to re-emit a second fluorescent luminous flux into the transparent light-guide layer. Other aspects include a set of indicators, a display device, and a watch comprising one or more movable indicators.