Windshield Head-Up Display Ghost Image Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current windshield head-up display systems suffer from ghost image issues due to image reflection by the windshield, requiring modifications to the windshield structure or coatings, which increase costs and are not feasible with an unchanged original windshield.
Innovation Solution
A windshield head-up display system that projects image information onto the windshield, forming two virtual images on the same side with the first image closer to the eye-box region, adjusting the imaging distance and astigmatism to reduce the ghost image value, using a projection assembly with reflecting mirrors and controlling diopter differences between tangential and sagittal plane images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the windshield structure or coating is modified to suppress ghost images, then the ghost image is reduced, but the manufacturing cost increases
Solution Approach 1:
The patent changes optical parameters (imaging distance, diopter, astigmatism) of the projection system rather than modifying the windshield structure or coating. By adjusting the imaging distance to be greater than 3 meters and controlling the diopter difference between tangential and sagittal planes, the ghost image is suppressed without requiring windshield modifications, thus avoiding increased manufacturing costs
Solution Approach 2:
The patent creates a virtual copy of the image at a different optical distance. By projecting the image to form a first virtual image at a specific imaging distance and controlling its optical parameters, the system effectively replaces the need for physical windshield modifications with an optical parameter-based solution
2Object-affected harmful factors
If the imaging distance is increased to suppress ghost images, then the ghost image value is reduced, but the system complexity increases
Solution Approach 1:
The patent suppresses ghost images by changing optical parameters (imaging distance > 3m, diopter difference control) rather than adding complex hardware components. This parameter-based approach reduces ghost image value while maintaining relatively simple system structure
Solution Approach 2:
The patent makes the imaging distance adjustable and optimizes it dynamically. By allowing the imaging distance to be greater than 3 meters and controlling astigmatism dynamically, the system adapts to different conditions to suppress ghost images without requiring complex fixed structures
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
The system effectively suppresses ghost images by extending the imaging distance and controlling astigmatism, reducing the ghost image value, and does not require special windshield coatings or structures, thus maintaining the original windshield while improving visibility.
Implementation Method 1
the first virtual image is formed after reflection of an inner surface of the windshield
Implementation Method 2
the second virtual image is formed after sequentially subjecting to refraction of the inner surface of the windshield, reflection of an outer surface of the windshield and refraction of the inner surface of the windshield
Data Source
AI summary
A windshield head-up display, and a method for suppressing a ghost image are disclosed. The windshield head-up display comprises an image source and a projection assembly. The image source is projected onto a windshield by means of the projection assembly, such that a first virtual image and a second virtual image are formed on the same side of the windshield. The first virtual image is closer to an eye-box region than the second virtual image. The distance from the first virtual image to the eye-box region is an imaging distance. The method comprises: measuring a ghost image value of the first virtual image and the second virtual image upon a change in the imaging distance; and if the imaging distance has increased, reducing the ghost image value of the first virtual image and the second virtual image projected by the projection assembly onto the same side of the windshield.