Watch Case Control Wheel with Magnetic Sensor Detection

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Solution Overview

Problem

Current watch user interfaces are limited and poorly suited for use in all conditions, especially in humid environments or with wet hands, and lack effective protection against shock and water exposure.

Innovation Solution

A watch case with a housing that allows a movable control wheel to be manipulated by the user for rotation and limited translation, equipped with elastic return means and detection mechanisms to activate sensor systems for contactless interaction, enabling control of watch functions without compromising water resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional user interfaces (crown, pushers, touch-sensitive crystals) are used, then the watch can be operated in basic conditions, but the interface becomes fragile and unsuitable for use in humid environments or with wet hands

Engineering Contradiction:
Improveoperability in all conditionsVSAvoidinterface durability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces conventional mechanical interfaces (crown, pushers) and touch-sensitive electronic interfaces with a magnetic field-based control system. The control wheel generates magnetic field variations that are detected by sensors, eliminating the need for direct electrical contacts or mechanical switches that are vulnerable to moisture and corrosion. This substitution of the control mechanism fundamentally resolves the contradiction by creating an interface that is both mechanically simple and environmentally robust.

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

Solution Approach 2:

The patent introduces magnetic field detection as an intermediary between the user's mechanical manipulation of the control wheel and the electronic control system. Instead of direct mechanical or electrical contact, the control wheel's position and movements are transmitted through magnetic field variations detected by non-contact sensors. This intermediary magnetic field transmission mechanism protects the electronic components from direct exposure to moisture while maintaining full operational capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the control wheel is made accessible for direct manipulation, then user interaction is improved, but water and shock protection is compromised

Engineering Contradiction:
Improvedirect user manipulationVSAvoidwater and shock exposure
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent employs a waterproof casing structure with magnetic field transmission capability that allows the control wheel to be manipulated through a sealed barrier. The control wheel is positioned such that it can be operated through the case back or side, which is sealed with waterproof materials that transmit magnetic fields. This allows direct user manipulation while maintaining the protective barrier against water and shock.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent replaces mechanical transmission mechanisms (gears, shafts penetrating the case) with magnetic field-based detection. The control wheel's rotational position and movements are detected through magnetic field variations that can be sensed through the waterproof case material, eliminating the need for mechanical penetrations that would compromise water and shock protection.

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

3Measurement precision

If sensor means are integrated near the housing for detecting wheel position, then control precision is improved, but the device complexity increases

Engineering Contradiction:
Improvewheel position detectionVSAvoidsensor integration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent integrates multi-functional sensor means that simultaneously detect the control wheel's angular position, rotational direction, and pressing actions. The magnetic field sensors serve multiple detection purposes: determining wheel position for menu navigation, detecting rotation direction for scrolling, and identifying pressing actions for selection. This multi-functionality reduces the need for separate sensors for each function, thereby limiting the increase in device complexity while maintaining high measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses magnetic field variations as an intermediary that encodes multiple control information (position, direction, pressing) in a single detection system. The magnetic field pattern changes in response to the control wheel's various movements, and the sensor means decodes these patterns to determine the user's intentions. This single intermediary mechanism replaces what would otherwise require multiple separate sensing systems, maintaining simplicity while achieving precise multi-parameter detection.

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

The solution provides a user-friendly and durable interface that operates effectively in humid conditions, maintaining water resistance and allowing intuitive control of watch functions with enhanced protection against shock and water exposure.

Implementation Method 1

against elastic return means which are arranged to move said part away from the inside of said case

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

sensor means included in said box near said housing, which sensor means are arranged to detect, during a rotational movement imparted by the user to said wheel, the passage of discontinuous emitting means included in said wheel

Methodology Applied
Scientific EffectElectromagnetic detection: Electromagnetic Induction

Data Source

PatentEP3440516B1Watch case with control means using a rotating ring
Publication Date: 2024.01.17 ETA SA MFG HORLOGERE SUISSE
  • EP3440516B1 patent drawingFigure 1~4
  • EP3440516B1 patent drawingFigure 5~10
  • EP3440516B1 patent drawingFigure 11~14

AI summary

A watch case (1) comprising a bezel (3) for controlling a function of the watch, to be handled by the user and movable in a recess (2) which is arranged to allow limited translational motion of a portion (30) of the bezel (3) in a radial direction of the case (1), counter to resilient return means (5) arranged to move this portion (30) away from the inside of the case (1); this recess (2) comprises a control detection means (7) detecting the presence of this portion (30) at the point closest to the centre of the case (1) when pressure is applied by a user, and arranged to activate or deactivate sensor means (8) which the case (1) comprises, close to the recess (2), and arranged to detect, when a rotational movement is imparted by the user to the bezel (3), the passage of transmitter means (9) which this bezel (3) comprises.