Pivoting Grooming Head Light Guide With Stable Optical Coupling

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Solution Overview

Problem

Maintaining effective optical coupling between movable and fixed parts of grooming devices with pivoting capability is challenging, especially when conveying light from a light source to a movable housing part for enhanced grooming precision.

Innovation Solution

A housing assembly with a fixed and movable light guide section and an optical coupling interface that maintains coupling in all pivot positions, utilizing windows with specific curvatures and dimensions to ensure efficient light delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a light guide is used to convey light from a fixed light source to a movable housing part in a grooming device with pivoting capability, then light delivery efficiency is improved, but maintaining effective optical coupling between movable and fixed parts becomes challenging

Engineering Contradiction:
Improvelight delivery efficiencyVSAvoidoptical coupling effectiveness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The light guide is divided into a fixed light guide section housed in the fixed housing part and a movable light guide section housed in the movable housing part. This segmentation allows each section to remain stable in its respective housing while maintaining optical coupling through the optical coupling interface, resolving the contradiction between light delivery efficiency and optical coupling reliability during pivoting movements.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the movable housing part is made pivotable to enhance grooming precision on curved skin surfaces, then adaptability is improved, but maintaining consistent optical coupling throughout the pivot range becomes difficult

Engineering Contradiction:
Improvegrooming adaptability to curved surfacesVSAvoidoptical coupling stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The optical coupling interface incorporates curved surfaces (spheroidal geometry) that are specifically designed to maintain optical coupling stability throughout the pivot range. The curved geometry allows the interface to accommodate angular changes while preserving the optical path between the fixed and movable light guide sections, enabling both pivoting adaptability and optical coupling stability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If the optical coupling interface is designed with specific size and shape to maintain coupling in all pivot positions, then optical coupling reliability is improved, but device complexity increases

Engineering Contradiction:
Improveoptical coupling reliabilityVSAvoidoptical coupling interface complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The optical coupling interface is designed with specific geometric parameters (curvature radius, aperture size, and shape dimensions) that are optimized to maintain optical coupling across the entire pivot range. By carefully selecting these parameters, the interface achieves reliable optical coupling without requiring overly complex structures, balancing reliability and device complexity.

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

Ensures consistent and efficient light delivery to the skin surface during pivoting movements, improving grooming precision and visibility.

Implementation Method 1

an optical coupling interface between the fixed light guide section and the movable light guide section, wherein the optical coupling interface is configured to maintain optical coupling in all pivot positions in the range

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP4703102A1Housing assembly for a grooming device
Publication Date: 2026.03.04 KONINKLIJKE PHILIPS NV
  • EP4703102A1 patent drawingFigure 1A
  • EP4703102A1 patent drawingFigure 1B
  • EP4703102A1 patent drawingFigure 2A

AI summary

A housing assembly for a grooming device comprises a fixed housing part affixable to a handle, and a movable housing part configured to house a grooming element. The movable housing part is pivotably connected to the fixed housing part for enabling pivoting movement over a range of pivot positions. The housing assembly further comprises a light guide having a fixed light guide section and a movable light guide section. The fixed light guide section is arranged to receive light from a light source and the movable light guide section is arranged to direct the light to a region of skin to be groomed. The fixed light guide section is housed within the fixed housing part and the movable light guide section is housed within the movable housing part, the movable light guide section being thereby constrained to follow the pivoting movement of the movable housing part relative to the fixed housing part over the range of pivot positions. The housing assembly further comprises an optical coupling interface between the fixed light guide section and movable light guide section. The optical coupling interface is configured to maintain optical coupling in all pivot positions in the range, thereby enhancing grooming precision and visibility.