Motor Vehicle Light Guide with Inclined Transitional Surface
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Solution Overview
Problem
Existing light guides for motor vehicle signal lamps face inefficiencies in binding and directing light rays, leading to suboptimal output light characteristics due to mechanical design limitations and light loss, particularly when using larger collimators, which can result in light exiting at unintended angles, affecting the required diffusion angles of 5° to 25° horizontally and 5° to 10° vertically.
Innovation Solution
A light guide with an integral collimating wall and a spatially shaped light guiding body that narrows from the collimator to the output surface, featuring a transitional surface with a specific inclination ratio defined by the relationship ab=tg(12arcsin(sinωn)), ensuring light rays are directed within the required diffusion angles, and optionally including a superstructural segment for improved design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a collimator with bigger dimensions is used at the input, then light binding efficiency is improved, but the light guide cannot provide a thin light emitting output surface
Solution Approach 1:
The light guide transitions from a cylindrical cross-section at the input to a flattened cross-section at the output, changing the dimensional characteristics along the propagation path. This allows the light guide to maintain a larger input aperture for efficient light binding while providing a thin output surface for the light trace, resolving the contradiction between input size and output thickness.
2Volume of moving object
If the light guide gets narrower in the direction from the light source, then output surface thickness is reduced, but light rays may exit under any angle from the output surface
Solution Approach 1:
Different sections of the light guide have different geometric properties optimized for their specific functions: the input section has a larger cylindrical cross-section for efficient light binding, while the output section is flattened to control the emission angle. The gradual transition between these sections ensures that light rays maintain the required angular distribution throughout the propagation path.
3Manufacturing precision
If the light guide body is spatially shaped with varying cross-section, then output light diffusion angle is controlled, but device complexity increases
Solution Approach 1:
The light guide employs smooth curved transitions between cylindrical and flattened cross-sections, avoiding sharp angles and complex geometries. This curved transition profile is easier to manufacture while still achieving the required light routing and angular control, reducing device complexity compared to more elaborate spatial shaping approaches.
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 effectively binds and directs light rays within the desired diffusion angles, ensuring a homogeneous output light trace while adapting to mechanical design constraints and maintaining low production costs, ensuring efficient light emission within the required angular specifications.
Implementation Method 1
at least one collimator with a collimating wall for binding and routing light rays emitted by the lighting means in the light guide
Implementation Method 2
a light guiding body that continues the collimating wall, is integral, spatially shaped, with a profile elongated in the direction of the optical axis
Data Source
AI summary
The light guide, especially for motor vehicle signal lamps, comprises a collimator with a collimating wall for binding and routing light rays, and a light guiding body that continues the collimating wall, is of a material with refractive index (n), and is integral, spatially shaped, planar, and fitted at its end with an output emitting surface providing a signal light function. The first height (d) of the body at its beginning where it adjoins the collimating wall, is bigger than its second height where it passes into the emitting surface. The body is adapted to emit light rays generally within angle (ω) of diffusion from the optical axis (x), and comprises a transitional surface that is, in its profile towards the emitting surface, inclined towards the longitudinal axis of the profile. The ratio of inclination height (a) and inclination length (b) of the transitional surface is defined as:ab=tg(12arcsin(sinωn))