Flat Light Guide With Oblique Reflective Zone For Uniform Illumination
Solution Overview
Problem
Existing vehicle lighting systems using flat light guides suffer from reduced light intensity directly in front of the light guide, leading to increased power consumption, temperature issues, and malfunctions, making them unsuitable for low or high beam functions.
Innovation Solution
Incorporating a compensating optical element on the reflective surface that reflects light obliquely to the side surface of the flat light guide, ensuring even illumination and directed output to the peripheral area of the light output surface, and using a combination of reflective surfaces to maintain intensity and directionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflective surface is used to improve light distribution, then illumination uniformity is improved, but light intensity in the direct forward direction is reduced
Solution Approach 1:
The reflective surface is divided into two distinct zones with different functions: a first zone that reflects light directly to the light output surface, and a second zone that reflects light obliquely to the side surface. This local differentiation allows each zone to optimize for its specific purpose, resolving the contradiction between uniform illumination and forward light intensity.
Solution Approach 2:
The reflective surface is segmented into functionally distinct areas (first zone and second zone) with different reflection angles and targets. This segmentation enables independent optimization of each zone's contribution to either uniformity or forward intensity, allowing both requirements to be met simultaneously.
2Illumination intensity
If light is reflected obliquely to the side surface, then peripheral illumination is improved, but light intensity in the direct forward direction may be reduced
Solution Approach 1:
The second zone of the reflective surface is specifically designed to reflect light obliquely toward the side surface, creating a localized function that targets peripheral illumination. This local quality assignment ensures that peripheral areas receive adequate light without compromising the overall forward intensity, as the first zone continues to provide direct forward reflection.
3Illumination intensity
If a collimating element is used to direct light, then light directionality is improved, but light intensity distribution becomes uneven
Solution Approach 1:
The reflective surface is segmented into zones that complement the collimating element's function. The first zone maintains the collimated light's directional properties while the second zone redistributes light to peripheral areas, thus preserving directionality while improving overall intensity distribution uniformity.
Solution Approach 2:
The reflective surface acts as an intermediary between the collimating element and the light output surface. It receives the collimated light and redistributes it through different reflection zones, mediating between the collimating element's directional focus and the need for uniform distribution across the output surface.
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 solution ensures even illumination and precise directional output of light from the peripheral area of the light output surface, maintaining desired intensity and directionality, thus enhancing the suitability for low and high beam functions without the need for more powerful light sources.
Implementation Method 1
a collimating element (2) which is arranged transversely or obliquely with respect to the base plane of the flat light guide (1)... and the collimating element is adapted for the entry of light from the light source into the light guide
Implementation Method 2
an obliquely inclined reflective surface (3) which is adapted to reflect light from the collimating element (2) into the light guide (1)
Implementation Method 3
the light guide (1) is adapted to guide light from the collimating element (2) between the side surfaces (11, 12) of the light guide (1) to the light output surface (13)
Implementation Method 4
at least one reflective surface (3) comprises at least one compensating optical element (30), which is adapted to reflect at least part of the light incident on this reflective surface (3) in the direction of rays obliquely to the side surface (12) of the flat light guide (1) as far as to the end tip area
Implementation Method 5
this side surface being adapted to reflect these rays into the peripheral area of the light output surface (13)
Data Source
AI summary
A flat light guide (1) for a vehicle lighting device, which includes a rear end (10) and a front end with a light output surface (13), the light guide (1) being defined between the two ends by a pair of side surfaces (11, 12). The light guide (1) has a base plane (X-Y) and at its rear end (10) is provided with at least one collimating element (2) arranged transversely or obliquely with respect to the plane (X-Y). Opposite the collimating element (2) is arranged an obliquely inclined reflective surface (3) to reflect light from the collimating element (2) into the flat light guide (1). The collimating element (2) is adapted for the light input from the light source into the light guide (1) which further guides the light between the side surfaces (11, 12) to the output surface (13).