U-Shaped Light Source for Dual-Mode Hair Removal and Skin Rejuvenation

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Solution Overview

Problem

Existing home-use IPL devices face challenges in achieving faster hair removal and effective skin rejuvenation due to limited space and fluence constraints, with larger treatment areas resulting in lower fluence and vice versa.

Innovation Solution

A dual-function treatment device with a U-shaped light source and reflector that can switch between configurations for hair removal and skin rejuvenation, utilizing a U-shaped light source to maintain fluence and increase treatment area for faster hair removal, and concentrate light for higher fluence in a smaller area for skin rejuvenation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the treatment area is increased to reduce treatment time, then productivity is improved, but fluence decreases

Engineering Contradiction:
Improvetreatment speedVSAvoidfluence
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The light source is configured in a U-shape rather than a straight line, effectively segmenting and redistributing the light emission along a curved path. This allows the light to cover a larger treatment area while maintaining adequate fluence through the geometric arrangement of the light-emitting segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light source transitions from a one-dimensional linear arrangement to a two-dimensional U-shaped configuration. This dimensional change allows the light source to cover a larger area while maintaining proximity to the treatment surface across the entire treatment zone, preserving fluence while increasing treatment area.

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

2Reliability

If the fluence is increased for skin rejuvenation, then treatment effectiveness is improved, but the treatment area must be reduced

Engineering Contradiction:
Improvetreatment effectivenessVSAvoidtreatment area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The system dynamically adjusts the operational parameters of the light source based on the selected treatment mode. For skin rejuvenation, the light source operates at higher fluence settings, while for hair removal, it operates at lower fluence but covers a larger effective treatment area through the U-shaped configuration.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The U-shaped light source configuration and associated optical components are designed to serve multiple functions: delivering high fluence for skin rejuvenation and providing extended coverage for hair removal. The same physical structure adapts its operational characteristics based on the treatment mode selected.

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

3Illumination intensity

If the light source size is increased to provide higher fluence, then illumination intensity is improved, but device size increases

Engineering Contradiction:
ImprovefluenceVSAvoiddevice size
Core Design Contradiction:
Illumination intensityVSVolume of moving object

Solution Approach 1:

The U-shaped light source is nested within the housing structure, with the reflector positioned to maximize light utilization within the available space. The compact U-shaped configuration allows the light source to be efficiently packaged within the device housing without requiring excessive volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The U-shaped (curved) light source configuration allows for more efficient packing within the device housing compared to a straight linear arrangement. The curved geometry enables better spatial utilization and compact integration of the optical components within the device form factor.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 device provides faster hair removal and improved skin rejuvenation without compromising compact size or effectiveness, achieving larger treatment areas with maintained fluence for hair removal and higher fluence for skin rejuvenation.

Implementation Method 1

a light source (12) for generating a light pulse (L)

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

a reflector (22) for reflecting the light pulse towards the light exit window (11)

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

The light penetrates the skin and is absorbed, among other places, in the root of the hair by the pigment melanin

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 4

This causes an increase in the temperature of the root of the hair to rise and subsequently the temperature of the surrounding tissue. The generated heat damages the hair follicles, and the growth of the hair is inhibited if the temperature rise is sufficient. This process is known as photothermolysis.

Methodology Applied
Scientific EffectPhotothermolysis:

Data Source

PatentEP4514257B1Treatment device for performing light-based treatment operations
Publication Date: 2025.09.03 KONINKLIJKE PHILIPS NV
  • EP4514257B1 patent drawingFigure 1
  • EP4514257B1 patent drawingFigure 2(a)~2(b)
  • EP4514257B1 patent drawingFigure 3(a)~3(b)

AI summary

According to an aspect, there is provided a treatment device (2; 400) for performing light- based treatment operations on or to a subject. The treatment device (2; 400) comprises a U-shaped light source (12; 202; 301; 402) for emitting a light pulse; a light exit window (10; 201) through which the light pulse is emitted from the treatment device (2; 400); and a reflector (302; 403) for reflecting the light pulse towards the light exit window (10; 201). The treatment device (2; 400) is configured to operate with the light source (12; 202; 301; 402) and the reflector (302; 403) in a first configuration (210; 310, 320) for performing hair removal on the subject, and with the light source (12; 202; 301; 402) and the reflector (302; 403) in a second configuration (220; 330) for performing skin rejuvenation on the subject.