Uniform Lighting Reflector with Segmented Hemispherical Reliefs

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Solution Overview

Problem

Existing reflectors for lighting apparatuses suffer from non-uniform light emission due to manufacturing irregularities and asymmetries in light sources, leading to inconsistencies in illuminance and chromaticity, particularly affecting the quality of lighting for displays and artworks.

Innovation Solution

A roto-symmetric reflector with a surface divided into approximately trapezoidal segments, featuring reliefs with a hemispherical shape and convexity, optimized for increased light mixing by adjusting the size and number of these segments and their reliefs, which enhances the uniformity and independence from surface flaws.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a roto-symmetric reflector with a smooth reflecting surface is used, then the manufacturing process is simple and cost-effective, but the light emission uniformity deteriorates due to surface irregularities causing spots and rings

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidlight emission uniformity
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The reflector's internal surface is divided into multiple surface segments, each with a curved reflecting surface. This segmentation transforms the smooth surface into a multi-faceted structure that redistributes light rays, eliminating the uniformity defects caused by manufacturing irregularities while maintaining manufacturing feasibility through molding techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each surface segment is equipped with a curved reflecting surface with specific curvature radius, creating local optical properties that differ from the overall reflector. This local curvature variation ensures that light rays reflected from different segments are distributed more uniformly in space, addressing the uniformity issue without complicating the overall manufacturing process.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If the reflecting surface is divided into surface segments with curved surfaces, then the light mixing and uniformity improve, but the device complexity increases

Engineering Contradiction:
Improvelight emission uniformityVSAvoidreflector structure complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The reflector is segmented into multiple surface elements, each with a curved reflecting surface. This segmentation creates a complex light-mixing effect that improves uniformity while keeping the overall structure manageable through systematic arrangement of the segments around the optical axis.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each surface segment incorporates a curved reflecting surface with a defined curvature radius. This curvature is optimized to achieve the desired light mixing effect and uniformity. The curvature parameter becomes a design variable that balances optical performance with manufacturing complexity, allowing standard molding techniques to be used.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Illumination intensity

If surface segments with specific curvature radius are used, then the light beam mixing and uniformity are improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvelight beam uniformityVSAvoidcurvature radius precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The curved reflecting surfaces of the surface segments are designed with specific curvature radii that are optimized for light mixing. By carefully selecting these curvature parameters, the invention achieves high light uniformity while maintaining compatibility with standard molding and turning manufacturing processes, avoiding the need for excessively tight precision tolerances.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The curvature radius of the surface segments is used as a key design parameter that can be adjusted to optimize the balance between light uniformity and manufacturing precision. By varying the curvature radius within a reasonable range, the invention achieves the desired optical performance without requiring extreme manufacturing precision that would be costly or difficult to obtain.

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

The reflector achieves a higher degree of light beam mixing, resulting in improved lighting uniformity and reduced color temperature variations, enhancing the overall quality of light emission and reducing the impact of surface irregularities and light source asymmetries.

Implementation Method 1

the reflection of a part of the emission of the light source takes place according to the local inclination of the reflector portion impinged by the incident light rays, in observance of the Euclidean theories according to which the incidence angle is equal to the reflection angle

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2626620B1Uniform lighting reflector for lighting apparatuses
Publication Date: 2020.12.09 IGUZZINI ILLUMINAZIONE
  • EP2626620B1 patent drawingFigure 1~2
  • EP2626620B1 patent drawingFigure 3~4

AI summary

The present invention relates to a reflector for light emission sources, having a rotational symmetry about an axis, an apex comprising a first opening of size such to accommodate a light source and a second opening, larger in size than the first opening, adapted to let out the direct light emitted by said light source and the light reflected by the internal surface of the reflector, surface which is has a series of segments (10) comprising a plurality of approximately rectangular surface segments in turn comprising a plurality of reliefs (13), preferably having a substantially hemispherical shape, and characterized by a convexity facing towards the inside of the reflector, said convexity being characterized by a single curvature radius.