Traffic Light Signalling with Serrated Lightpipe for Solar Contrast

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Solution Overview

Problem

Existing traffic light technologies, particularly those using incandescent and halogen lamps, face issues with depth, size, energy efficiency, and contrast due to reflective surfaces and the inefficiency of Fresnel lenses in gathering and directing light, especially under solar conditions, leading to reduced contrast and energy loss.

Innovation Solution

A light system comprising a primary lightpipe with a serrated structure on its back side for efficient light reflection and absorption, featuring a light-absorbing surface perpendicular to the back side, and optionally a secondary lightpipe for uniform distribution, along with a collector lens and separator to manage light beams, reducing back reflections and enabling thinner, more efficient designs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If incandescent or halogen lamps with reflective surfaces are used, then light can be directed at desired angles, but the light structure requires more depth and bigger dimensions

Engineering Contradiction:
Improvelight direction controlVSAvoidlight structure depth
Core Design Contradiction:
Illumination intensityVSLength of stationary object

Solution Approach 1:

The patent replaces traditional mechanical reflective surfaces with a lightpipe structure that uses total internal reflection to direct light. The lightpipe has specific geometric features (first and second surfaces with different orientations) that guide light from the source to the exit face without requiring deep mechanical reflectors, thus reducing the overall depth of the light structure while maintaining directional control.

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

Solution Approach 2:

The invention transitions from using reflective surfaces in a traditional depth-oriented arrangement to a lightpipe structure where light propagation occurs through a different dimensional path - entering through the side face and exiting through the front face, utilizing internal reflection geometry to achieve light direction control with reduced depth requirements.

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

2Illumination intensity

If incandescent or halogen lamps with reflective surfaces are used, then light can be distributed homogeneously, but the light source must be located at a certain distance from the lens, increasing dimensions

Engineering Contradiction:
Improvelight intensity homogeneityVSAvoidlight structure footprint
Core Design Contradiction:
Illumination intensityVSArea of stationary object

Solution Approach 1:

The patent replaces the need for spaced lens arrangements with a lightpipe structure that inherently distributes light homogeneously through its geometric design. The lightpipe's internal reflection surfaces and face orientations ensure uniform light emergence across the exit face, eliminating the need for additional spacing between light source and lens, thus reducing the overall footprint.

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

3Illumination intensity

If reflective surfaces are used in traffic lights, then light can be directed appropriately, but solar rays reflect back and reduce the contrast ratio

Engineering Contradiction:
Improvelight direction controlVSAvoidsolar reflection interference
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces traditional reflective surfaces with a lightpipe structure that uses total internal reflection. This substitution prevents solar ray back-reflection because the lightpipe geometry channels light in a controlled manner through its internal surfaces, blocking external solar radiation from reflecting back to drivers, thus maintaining high contrast ratio while preserving light direction control.

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

4Illumination intensity

If a Fresnel lens is used to gather light, then parallel light beams can be formed, but light gathering efficiency is insufficient and structure depth increases

Engineering Contradiction:
Improveparallel light beam formationVSAvoidlight gathering efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent replaces the Fresnel lens with a lightpipe structure that achieves parallel light beam formation through its geometric configuration. The lightpipe's internally reflected light paths are designed to emerge as parallel beams from the exit face, achieving the same optical effect as a Fresnel lens but with higher light gathering efficiency and reduced structural depth.

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

5Object-affected harmful factors

If colored lenses are used to increase contrast, then solar spectrum absorption improves, but light source energy is lost due to absorption in the lens

Engineering Contradiction:
Improvesolar spectrum filteringVSAvoidlight source energy absorption
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent replaces colored lenses with a lightpipe structure that achieves solar spectrum filtering through its geometric design and surface orientations. The lightpipe structure blocks harmful solar radiation from reflecting back while allowing the desired light signals to pass through, eliminating the energy absorption losses associated with colored lenses while maintaining contrast enhancement.

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

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 enhances light intensity distribution, reduces back reflections, and increases contrast while maintaining energy efficiency, allowing for thinner and more compact traffic light designs that can handle solar conditions effectively.

Implementation Method 1

the second surface is provided with a light absorbing surface

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

the first surface is provided with a reflecting surface to reflect light from the light source

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

the front side constructed and arranged to internally reflect the light received from the light source to the back side of the primary lightpipe

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3209929B1Signalling light for traffic control
Publication Date: 2020.02.19 ORTANA ELEKTRONIK YAZILIM TAAH SAN VE TIC AS
  • EP3209929B1 patent drawingFigure 1~3
  • EP3209929B1 patent drawingFigure 4~5
  • EP3209929B1 patent drawingFigure 6~7

AI summary

The invention relates to a light comprising: a primary lightpipe (2); and, a light source (1 ). The primary lightpipe may have: a lightpipe inlet side (3) constructed and arranged to receive light from the light source and to allow it to enter the primary lightpipe; a back side (6b) being provided with a serrated structure (5) comprising a reflecting surface (10) to reflect light from the light source; and, a front side (6a) constructed and arranged to internally reflect the light received from the light source to the back side of the primary lightpipe and to transmit light received from the reflecting surface.