Vehicle Mirror Display Light Guide with Variable Refraction Elements
Solution Overview
Problem
Existing display devices for rear view mirrors in vehicles face challenges in achieving uniform light illumination and high light densities across different viewing angles, making it difficult to effectively assist drivers with blind spot detection.
Innovation Solution
The display device incorporates a light-conducting body with optical elements that vary in refraction and reflection behavior based on their distance from the coupling-in section, featuring a multi-layer reflection means and a mask with sawtooth-patterned coupling-out regions to adjust light density, ensuring high light density across various viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light guide plate with diffraction gratings is used to spread and diffract light, then light distribution is improved, but manufacturing complexity and precision requirements increase
Solution Approach 1:
The light guide plate is divided into multiple sections along the light propagation direction, with each section containing diffraction gratings at different positions. This segmentation allows independent optimization of each section's diffraction characteristics, reducing the overall manufacturing precision requirements while maintaining good light distribution across different viewing angles.
Solution Approach 2:
Different regions of the light guide plate are equipped with diffraction gratings having different parameters (such as different groove depths, spacing, or orientations). This local quality variation enables each region to contribute differently to light distribution, achieving uniform illumination across various viewing angles without requiring high precision throughout the entire structure.
2Adaptability or versatility
If optical elements are added to control light distribution, then viewing angle performance improves, but device complexity increases
Solution Approach 1:
The diffraction grating structure is integrated directly into the light guide plate, merging the light guiding function and the light diffusing function into a single component. This eliminates the need for separate optical elements and reduces overall device complexity while maintaining good viewing angle characteristics.
Solution Approach 2:
The light guide plate serves multiple functions simultaneously: it guides light from the light source, distributes light uniformly, and controls light emission at different angles through its integrated diffraction grating structure. This multi-functionality reduces the number of separate components needed in the optical unit.
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 configuration ensures consistent and high light density across different viewing angles, enhancing the visibility of symbols or warnings for the driver, thereby improving safety by providing uniform illumination and clear visual cues.
Implementation Method 1
light from a light source falls on a light guide plate of a light incident surface. Within the light guide plate, the incident light spreads in the longitudinal direction while it is repeatedly totally reflected at the top and bottom surfaces of the light guide plate.
Implementation Method 2
A multiplicity of diffraction gratings is formed continuously on the top and/or bottom surface of the light guide plate in order to form a hologram pattern. Some of the light which spreads in the light guide plate is therefore diffracted and emitted at the top of the light guide plate.
Implementation Method 3
which comprises at least one optical element by means of which a beam path of at least the light passing through the optical element can be deflected and/or split into light bundles
Implementation Method 4
which comprises at least one optical element by means of which a beam path of at least the light passing through the optical element can be deflected and/or split into light bundles, in particular scattered
Data Source
AI summary
A display arrangement for a motor vehicle can be disposed in a rear view device such as an interior- or exterior rear view mirror. The display arrangement may include at least one light source and at least one optical unit. The at least one optical unit may include at least one light-conducting body having at least one coupling-in section through which light emitted by at least one light source can be coupled into the light-conducting body and having at least one coupling-out section through which light can be coupled out of the light-conducting body. The at least one optical unit also comprises at least one optical means which at least in some sections is or can be secured to the light conducting body such that it is overlaid on the surface of the at least one coupling-out section of said light-conducting body. The optical means comprises at least one optical element by means of which a beam path of at least the light passing through the optical element can be deflected and/or split into light bundles, in particular scattered. The display arrangement is characterized in that the optical means includes a plurality of optical elements which, when they are at the same distance from the coupling-in section of the light-conducting body, correspond in their refraction- and/or reflection behavior and, in the opposite case, differ. Further provided are a rear view device comprising such a display arrangement, and a motor vehicle comprising such a rear view device.