Head-Up Display Cover Element Polarization Conversion
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Solution Overview
Problem
Head-up display devices for motor vehicles experience significant light losses due to transmission through transparent cover elements and reflection on windshields, leading to inefficiencies and increased power requirements for image generation.
Innovation Solution
The head-up display device emits light as p-polarized light, which is transmitted through a cover element designed to convert it into s-polarized light, optimizing reflection on the windshield and minimizing light losses, using a polarization-converting coating or a polycarbonate film as the cover element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transparent cover element is used to protect the image generation unit, then protection from dust and contaminants is improved, but light loss increases due to transmission through the cover element
Solution Approach 1:
The patent changes the polarization parameter of light to resolve the contradiction. By emitting p-polarized light instead of unpolarized or s-polarized light, the system achieves significantly reduced light loss (up to 20% improvement) while maintaining the protective function of the transparent cover element. The cover element's transmission characteristics for p-polarized light are optimized to minimize energy loss.
2Illumination intensity
If the image generation unit emits higher power light to compensate for light loss, then display visibility is improved, but power consumption increases
Solution Approach 1:
The patent changes the polarization state parameter of the emitted light to p-polarization, which fundamentally alters the transmission characteristics through the cover element and reflection characteristics at the windshield. This parameter change enables high display visibility with reduced power consumption, as the p-polarized light experiences minimal loss (up to 20% improvement) compared to conventional lighting approaches.
3Loss of energy
If multiple polarization converters are used to optimize light polarization, then light efficiency is improved, but device complexity increases
Solution Approach 1:
The patent extracts the polarization conversion function from separate converter components and integrates it directly into the cover element itself. By incorporating a polarization-converting coating or using a polycarbonate film with inherent polarization properties, the system achieves the desired light efficiency (reducing light loss) while eliminating the need for multiple discrete polarization converters, thus simplifying the overall device structure.
Solution Approach 2:
The patent merges the protective cover element function with the polarization conversion function into a single integrated component. The cover element is designed to simultaneously protect the image generation unit from contaminants and convert/optimze the polarization state of transmitted light. This consolidation reduces device complexity by eliminating separate polarization converter components while maintaining or improving light efficiency.
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 approach increases the efficiency of the head-up display by up to 20%, reduces power consumption, and avoids the need for multiple polarization converters, while maintaining high light and energy efficiency and compatibility with polarizing sunglasses.
Implementation Method 1
The cover element is designed to convert at least predominantly of the p-polarized light emitted by the image generation unit into s-polarized light during transmission
Implementation Method 2
the housing having a transparent cover element designed to transmit the light emitted by the image generation unit
Implementation Method 3
an optical device, such as reflectors or mirrors, that projects the light emitted by the image generation unit onto a display element
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a top-mounted display device (3) for a motor vehicle, comprising an image generator (4) designed to emit light (P) to provide a display, and a housing (5) in which the image generator (4) is arranged, the housing (5) having a transparent cover element (6) designed to transmit the light emitted by the image generator (4). The top-mounted display device (3) is further configured such that, for displaying the display provided by the image generator (4), the light (P) emitted by the image generator (4) is at least partially transmitted through the cover element (6).Furthermore, the image generation unit (4) is configured to emit the light (P) at least to a large extent as p-polarized light (P) for the purpose of providing the display, wherein the cover element (6) is configured to convert the p-polarized light (P) emitted by the image generation unit (4) at least to a large extent into s-polarized light (S) during transmission.