Virtual Image Display Diffractive Optical Elements Windshield Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional virtual image display devices for vehicles face challenges in maintaining image quality and robustness due to varying windshield shapes, leading to deformation and reduced visibility.
Innovation Solution
The virtual image display device incorporates a light guide unit with a negative and positive diffractive optical element, which guides display light to correct image deformation and maintain robustness across different windshield shapes without requiring curved surfaces, using a combination of diffractive structures to adjust optical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional projection methods are used on windshields with varying shapes, then the device can be mounted on different vehicles, but the image becomes deformed and visibility is reduced
Solution Approach 1:
The patent uses diffractive optical elements with specific diffraction patterns to change the optical parameters of the projection system. By controlling the diffraction angles and light distribution, the system maintains accurate image projection on windshields of varying shapes without deformation, resolving the contradiction between adaptability and image quality.
2Adaptability or versatility
If curved surfaces are used to accommodate different windshield shapes, then adaptability improves, but device complexity increases
Solution Approach 1:
The patent replaces complex curved mechanical surfaces with planar diffractive optical elements that achieve the same adaptive function through optical diffraction. This substitution maintains adaptability to different windshield shapes while significantly reducing the mechanical complexity of the projection device.
3Manufacturing precision
If diffractive optical elements are used to correct image deformation, then image quality improves, but chromatic aberration occurs
Solution Approach 1:
The patent applies different diffraction patterns to different regions of the optical element, with each region optimized for specific wavelength ranges. This local optimization corrects chromatic aberration by directing different colors along appropriate optical paths while maintaining overall image quality.
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 enhances the robustness and visibility of the virtual image by minimizing changes in other components and correcting image deformation accurately, regardless of windshield shape, while reducing chromatic aberration and allowing for a commonized design.
Implementation Method 1
The light guide unit includes a negative diffractive optical element and a positive diffractive optical element
Implementation Method 2
cause a projection portion to reflect a display light of an image to display the image as a virtual image
Data Source
AI summary
A light guide unit forms an optical path to guide a display light emitted from a display unit toward a projection portion. The light guide unit includes a negative optical element and a positive optical element. The negative optical element is placed on the optical path and has a negative optical power. The positive optical element is placed on the optical path and is closer to the projection portion than the negative optical element. The positive optical element has a positive optical power. The positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light.