Vehicle HUD Optics Using Polarized Solar-Light Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing information display apparatuses for vehicles face challenges in reducing damage to liquid crystal display elements due to solar light, particularly with large concave mirrors that collect and direct solar light into the system, leading to image quality degradation.
Innovation Solution
The apparatus incorporates a dielectric multilayer film on the surface of mirrors and lenses to selectively reflect or transmit light based on polarizing direction and wavelength, effectively blocking or reducing incident solar light without compromising image quality, and uses a transparent cover with polarizing films to manage polarized light components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a large concave mirror is used to enlarge the virtual image region, then the display area is increased, but solar light is collected and concentrated onto the liquid crystal display element causing damage
Solution Approach 1:
A polarizing film is introduced as an intermediary component between the liquid crystal display element and the optical path. This polarizing film selectively blocks polarized solar light while allowing the display image light to pass through, thereby protecting the liquid crystal display element from solar light damage without compromising the enlarged display area provided by the large concave mirror
Solution Approach 2:
The invention changes the polarization state parameter of the light by using a polarizing film. The polarizing film is configured to block polarized light from the sun while transmitting the display image light, effectively differentiating between harmful solar light and useful display light based on their polarization characteristics
2Object-affected harmful factors
If a light polarizing member is pasted on a glass substrate to block polarized solar light, then solar light damage is reduced, but flatness cannot be secured and image quality deteriorates
Solution Approach 1:
Instead of using a separate pasted polarizing film on a glass substrate, the invention forms a dielectric multilayer film that directly provides the polarizing function as an integrated optical coating. This dielectric multilayer film achieves the polarizing effect through its layered structure without requiring additional substrates or pasting processes, thereby maintaining flatness and image quality while blocking polarized solar light
3Object-affected harmful factors
If a dielectric multilayer film is formed on mirror or lens surface, then polarized solar light is blocked and image quality is maintained, but the manufacturing process becomes more complex
Solution Approach 1:
The invention merges the polarizing function with the existing dielectric multilayer coating process for mirrors and lenses. By integrating the solar light blocking function into the standard optical component manufacturing process, the system achieves polarized light blocking without adding separate manufacturing steps or components, thereby maintaining relatively simple manufacturing processes while protecting against solar light damage
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 reliably reduces solar light damage to the liquid crystal display elements while maintaining high-quality display images, enhancing the durability and performance of the information display system.
Implementation Method 1
a dielectric multilayer film on a surface of a mirror or a lens, the dielectric multilayer film having a property that selectively reflects/transmits light in a desirable polarizing direction or with a desirable wavelength
Implementation Method 2
the dielectric multilayer film having a property that selectively reflects/transmits light in a desirable polarizing direction
Implementation Method 3
by using a light polarizing member (film) pasted on a glass substrate arranged in front of a liquid crystal display element that is the image display device, transmit the polarized light that has been emitted from a light source and has penetrated the liquid crystal display element but to block a polarized component of the incident solar light entering the apparatus from outside
Data Source
AI summary
The information display apparatus has a housing with an opening and a transparent cover formed on the opening, the housing includes image-light generating means configured to generate image light that displays the image information and an optical system configured to allow a driver of the vehicle to recognize image information based on the image light from the image-light generating means as a virtual image in front of the windshield. When S-polarized light on the windshield is assumed to be a first polarized wave while polarized light that orthogonally crosses the S-polarized light in a polarizing direction is assumed to be a second polarized wave, the image-light generating means is configured to generate the image light made of the first polarized wave, and a transmittance/reflectance control means blocks a part of the first polarized wave and the second polarized wave of incident external light entering the housing from the opening.