Dielectric Multi-Layer Filter for UV Recycling in Illuminating Elements

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Solution Overview

Problem

Conventional illuminating elements, such as fluorescent lamps, suffer from reduced energy efficiency and non-uniform brightness due to ultraviolet light decay and incomplete absorption, leading to wasted energy and inferior brightness.

Innovation Solution

The implementation of a dielectric optical multi-layer filter that reflects ultraviolet light back onto an exciting coating within the illuminating element, enhancing energy utilization and brightness by ensuring complete absorption and efficient conversion to visible light across a wide range of angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the fluorescent film is made thicker to fully absorb ultraviolet light, then energy efficiency is improved, but the brightness uniformity deteriorates because ultraviolet light decays as it passes through the film

Engineering Contradiction:
Improveenergy efficiencyVSAvoidbrightness uniformity
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent implements continuous circulation of ultraviolet light through the fluorescent film by introducing a reflecting film. UV light that passes through the fluorescent film is reflected back and re-absorbed, ensuring continuous useful action and complete energy utilization without decay-related non-uniformity.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

A reflecting film is introduced as an intermediary component between the fluorescent film and the transparent closed tube. This mediator reflects UV light back onto the fluorescent film, enabling complete absorption while maintaining brightness uniformity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the fluorescent film is made thinner to enhance transparency, then brightness is improved, but energy efficiency deteriorates due to incomplete absorption of ultraviolet light

Engineering Contradiction:
ImprovebrightnessVSAvoidenergy efficiency
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The reflecting film enables continuous circulation of UV light, allowing thin fluorescent film to absorb UV light multiple times. This ensures complete energy absorption while maintaining the brightness advantages of a thin film structure.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The reflecting film acts as an intermediary that redirects UV light back onto the thin fluorescent film, enabling complete absorption without requiring increased film thickness, thus preserving brightness while improving energy efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If conventional dichroic mirror is used to reflect ultraviolet light, then energy efficiency is improved within narrow angle range, but the reflectance deteriorates when angle of incidence exceeds 15 degrees

Engineering Contradiction:
Improveenergy efficiencyVSAvoidreflectance stability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the key parameter of the reflecting film from angle-dependent (conventional dichroic mirror with 15° limit) to angle-independent (wide AOI reflectance LPF with 0-90° effectiveness). This parameter change ensures stable reflectance across all angles of incidence, maintaining both energy efficiency and reliability.

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

This solution significantly improves illuminating efficiency and brightness uniformity by ensuring that ultraviolet light is fully utilized, resulting in enhanced light output and energy utilization.

Implementation Method 1

a dielectric optical multi-layer filter that reflects ultraviolet light back onto an exciting coating

Methodology Applied
Scientific EffectOptical reflection: Reflection

Implementation Method 2

exciting coating within the illuminating element, enhancing energy utilization and brightness by ensuring complete absorption and efficient conversion to visible light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP1970939B1Light illuminating element
Publication Date: 2021.04.14 MII JENN WEI
  • EP1970939B1 patent drawingFigure 1
  • EP1970939B1 patent drawingFigure 1A~1B
  • EP1970939B1 patent drawingFigure 2

AI summary

A light illuminating element including a transparent closed casing (310), an exciting gas (320), a first exciting coating (330), and a first dielectric multi-layer long-pass filter (340) is provided. The transparent closed casing has a first inner side (312), a second inner side (316), a first outer side (314) corresponding to the first inner side, and a second outer side (318) corresponding to the second inner side. The exciting gas is disposed inside the transparent closed casing, and suitable for providing an ultraviolet light (322). The first exciting coating is disposed on the first inner side or the first outer side, and is suitable for absorbing the ultraviolet light to provide a visible light (324). The first dielectric multi-layer long-pass filter is disposed on the second inner side or the second outer side, and suitable for reflecting the ultraviolet light and allowing the visible light to pass through.