Bicycle Rear Light with Stepped Light Guide for Distance Estimation
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Solution Overview
Problem
It is difficult for road users approaching a bicycle from behind in the dark to estimate the distance based on the intensity of a punctiform rear light, which lacks angular extent for accurate distance perception.
Innovation Solution
A rear light design featuring a light-emitting diode with a light guide that laterally deflects light into multiple partial bundles, creating a bar-like appearance by using a stepped and curved light guide structure, allowing for better distance estimation due to its apparent angular extent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a punctiform light source is used for the rear light, then the device complexity is low and manufacturing is simple, but the distance estimation capability for road users is poor
Solution Approach 1:
The light guide structure is segmented into multiple planar sections and curved sections that form a stepped configuration. Each section serves a specific function in directing light, creating multiple partial light bundles that collectively form a bar-shaped radiation pattern. This segmentation transforms a simple point light source into a complex optical system that provides distance estimation capability through its extended angular extent.
Solution Approach 2:
The invention transitions from a zero-dimensional point light source to a one-dimensional bar-shaped light distribution by introducing a light guide with extended dimensions. The light guide creates radiation in multiple directions (angular extent) while maintaining a compact physical footprint, effectively adding spatial dimensionality to the light emission pattern without significantly increasing the device complexity.
2Illumination intensity
If a light guide with extended dimensions is used to create bar-shaped radiation, then the angular extent and visibility are improved, but the light loss increases
Solution Approach 1:
The invention optimizes the geometric parameters of the light guide, including the angles of planar sections, curvature radii of curved sections, and overall dimensions, to achieve efficient light distribution. By carefully selecting these parameters, the design maximizes the angular extent of radiation (improving visibility) while minimizing light loss through optimized total internal reflection paths within the light guide structure.
3Reliability
If a flat rear light design is implemented, then the safety and visibility are improved, but the cleaning accessibility may be reduced
Solution Approach 1:
The light guide's flat external design allows it to be easily cleaned by simply wiping the surface, as the flat geometry does not trap dirt in complex crevices. The stepped internal structure is enclosed and does not interfere with external cleaning operations. This self-service cleaning capability maintains the high safety and visibility benefits of the flat design without compromising ease of maintenance.
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 design enhances visibility and distance estimation by presenting a quasi-bar-shaped radiation pattern, improving safety without significant light loss, and enabling a compact, flat, and easily cleanable rear light.
Implementation Method 1
the light guide being designed such that it laterally deflects at least part of the light that can be generated in the light-emitting diode and deflects it again into various partial light bundles
Implementation Method 2
the boundary surfaces of which run at such an angle to the main direction of emission and have such a shape and depth that light emitted by the light-emitting diode is totally reflected into the light guide
Data Source
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AI summary
The light (1) has an LED (2), and a light conductor (3) attached to the LED and provided in a main radiation direction (H) before the LED, where the conductor is arranged in a plane perpendicular to main radiation direction. The light conductor is formed such that the conductor laterally diverts a portion of the light generated from the LED and divides into different partial light bundles (9) spaced from each other and again returns with a preset intensity distribution at a preset angle (beta) range in radiation direction. The light conductor has a flat outer side (4) and an inner side (5).