Illuminating Device with Spectral Differentiation for Pedestrian Visibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Drivers of automobiles have difficulty visualizing pedestrians on footways, especially at night, due to illuminance deficiencies and the way human vision operates under mesopic conditions, leading to potential delays in reacting to pedestrians crossing the roadway.
Innovation Solution
An illuminating device with distinct spectral characteristics for the footway and roadway, using blue-green light for the footway and green-red light for the roadway, where the spectral radiant intensity is adjusted to prioritize short wavelength light for the footway to enhance visibility under scotopic vision, with a 30% greater value to create a clear luminance difference, and long wavelength light for the roadway to match photopic vision sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If uniform illumination is provided to both roadway and footway using conventional light sources, then general visibility is maintained, but pedestrians on the footway remain difficult to visualize due to mismatch with human visual sensitivity characteristics
Solution Approach 1:
The patent applies local quality by providing different spectral characteristics to different areas: the footway side light source emits light with spectral characteristics rich in blue-green color light (short wavelength) to match scotopic vision sensitivity for pedestrian detection, while the roadway side light source emits light with spectral characteristics rich in green-red color light (long wavelength) for general illumination. This localized spectral differentiation enhances pedestrian visibility without requiring complete system redesign.
Solution Approach 2:
The patent changes the spectral parameter of the light sources based on location. The footway side light source is configured to emit light with a spectral power distribution that emphasizes short wavelengths (blue-green region), while the roadway side light source emits light emphasizing long wavelengths (green-red region). This parameter change aligns the illumination characteristics with human visual sensitivity under different viewing conditions, specifically optimizing for pedestrian detection in the footway area.
2Illumination intensity
If blue-green light is used for footway illumination to match scotopic vision sensitivity, then pedestrian visibility is enhanced, but energy distribution efficiency decreases due to non-uniform spectral output
Solution Approach 1:
The patent implements local quality by assigning different spectral energy distributions to different light sources based on their functional requirements. The footway side light source concentrates energy in the blue-green spectral region (short wavelength) to maximize perceived brightness under scotopic vision conditions, while the roadway side light source distributes energy in the green-red spectral region (long wavelength) for general illumination. This localized energy optimization ensures efficient energy use tailored to specific visual detection needs.
Solution Approach 2:
The patent changes the spectral energy distribution parameter of the light sources to match human visual sensitivity characteristics. The footway side light source is configured with spectral power distribution emphasizing short wavelengths where scotopic vision sensitivity peaks, thereby maximizing perceived brightness per unit of energy consumed in that specific area, while maintaining different energy distribution for the roadway area.
3Device complexity
If conventional light sources are used for both roadway and footway, then device complexity is minimized, but the driver cannot easily detect pedestrians due to illuminance deficiency and visual characteristics
Solution Approach 1:
The patent applies local quality by differentiating the spectral characteristics of light sources according to their specific functional roles. The footway side light source uses spectral characteristics rich in blue-green color light optimized for detecting pedestrians under scotopic vision conditions, while the roadway side light source uses spectral characteristics rich in green-red color light for general roadway illumination. This localized optimization enhances detection reliability without requiring complete system replacement.
Solution Approach 2:
The patent changes the spectral parameter of the light sources to improve detection reliability. By configuring the footway side light source to emit light with spectral power distribution emphasizing short wavelengths (blue-green region), the system aligns with human visual sensitivity under low-light conditions, thereby improving pedestrian detection reliability while maintaining relatively simple device structure through selective parameter adjustment rather than complete system redesign.
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 allows drivers to more easily and clearly visualize pedestrians on the footway by increasing the perceived brightness by 10% compared to the roadway, ensuring safer nighttime driving conditions by optimizing light spectral characteristics for human visual sensitivity.
Implementation Method 1
a footway side light source portion for irradiating light of spectral characteristics rich in blue-green color light
Implementation Method 2
a roadway side light source portion for irradiating light of spectral characteristics rich in green-red color light
Data Source
AI summary
An illuminating device able to easily visualize a pedestrian, etc. on a footway by the driver of an automobile is provided. The illuminating device has a footway side light source portion for irradiating light of spectral characteristics rich in blue-green color light to the footway, and a roadway side light source portion for irradiating light of spectral characteristics rich in green-red color light to a roadway. Further, the spectral characteristics of the light irradiated from the footway side light source portion are set such that a value Ip obtained by the following formula (1) is greater than a value IC obtained by the following formula (1) from the spectral characteristics of the light irradiated from the roadway side light source portion.I=∫abS(λ)·V′(λ)ⅆλ∫380780S(λ)·V(λ)ⅆλ(1)