LED Rear Lamp Light Guide for Bicycle Visibility
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Solution Overview
Problem
Existing bike rear lamps often suffer from inefficient operation due to weak side visibility and inefficient use of light, as they either rely on stray light or additional LEDs for side visibility, which compromises rear visibility.
Innovation Solution
A compact LED rear lamp design featuring a light guide with a plate-like shape and central aperture, where LEDs emit light directly towards the inner side face, allowing a portion to escape through outer side faces for side visibility and using internal reflection or scattering to direct light towards the rear main surface for enhanced rear visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If additional LEDs are used for side visibility, then side visibility is improved, but rear visibility and operational efficiency deteriorate
Solution Approach 1:
The patent makes the light guide serve multiple functions: it guides light for rear visibility while simultaneously allowing direct light transmission for side visibility. This single component replaces what would traditionally require separate LED elements, achieving universal functionality and improving operational efficiency while maintaining both visibility requirements.
Solution Approach 2:
The patent combines the functions of rear illumination and side illumination into a single optical system using one or more LEDs coupled with a light guide. By merging these functions, the design eliminates the need for additional dedicated side-visibility LEDs, thereby improving operational efficiency while achieving both visibility goals.
2Illumination intensity
If stray light is used for side visibility, then side visibility is improved, but operational efficiency deteriorates
Solution Approach 1:
The patent applies local quality by creating different optical pathways within the light guide: one pathway allows direct light transmission for side visibility without energy loss, while another pathway uses internal reflection for rear visibility. This localized differentiation of light transmission quality optimizes energy utilization while achieving both visibility requirements.
3Illumination intensity
If light is internally reflected multiple times for rear visibility, then rear visibility is improved, but light loss increases
Solution Approach 1:
The patent applies partial action by allowing a portion of the light to escape directly through the light guide for side visibility without undergoing multiple reflections, while only the necessary portion is internally reflected for rear visibility. This partial utilization of the light path minimizes energy loss while achieving adequate illumination in both directions.
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 design achieves efficient operation with improved rear and side visibility by optimizing light usage, ensuring that a significant portion of emitted light is utilized effectively for both rear and side illumination without additional reflections or attenuation.
Implementation Method 1
The light guide is designed to guide a first portion of the emitted light to escape through at least two opposing outer side faces of the light guide and to internally reflect or scatter a second portion of the emitted light traveling towards the two outer side faces to escape through a main surface of the light guide
Implementation Method 2
The light guide is designed to guide a first portion of the emitted light to escape through at least two opposing outer side faces of the light guide and to internally reflect or scatter a second portion of the emitted light traveling towards the two outer side faces
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to a LED rear lamp comprising a light guide (1) arranged in or forming part of a housing (10), said light guide (1) having a plate-like shape with a central aperture (2) surrounded by an inner side face (9) of the light guide. One or several LEDs (3) are arranged in the central aperture (2) such that a main emission direction of each LED (3) is aligned towards the inner side face (9) to couple emitted light through the inner side face (9) into the light guide (1). The light guide (1) is designed to guide a first portion (5) of the emitted light to escape through at least two opposing outer side faces (4) of the light guide (1) and to internally reflect or scatter a second portion (6) of the emitted light traveling towards the two outer side faces (4) to escape through a main surface (7) of the light guide (1). With the proposed LED rear lamp a good rear and side visibility is achieved in an efficient manner.