Waveguide HUD Image Correction for Ghost Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional head-up displays (HUDs) face issues of large volume and high manufacturing costs due to complex optical designs and strict tolerance requirements, as well as ghost images caused by windshield reflections, which affect imaging quality and driver safety.
Innovation Solution
An image processing method that includes generating a two-dimensional output image, guiding it through a waveguide, capturing a three-dimensional image, calculating errors using photometric and geometric methods, and correcting the image using a PNP algorithm to minimize distortion and ghosting, with features like edge absorbers and corner protectors to enhance image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional two-stage specular reflection technology is used in HUD, then the field of view can be widened, but the volume of the HUD increases due to requiring a large second-stage aspherical reflector
Solution Approach 1:
The patent replaces the conventional mechanical optical reflection system with a light field lens array system that uses refraction and direct light transmission. This substitution eliminates the need for large aspherical reflectors while achieving the same field of view expansion, thereby reducing the overall HUD volume.
Solution Approach 2:
The patent introduces a light field lens array that manipulates light in multiple dimensions through lens positioning and orientation. By controlling light propagation in three-dimensional space rather than relying on two-stage reflection, the system achieves wider field of view without increasing the physical footprint of the HUD device.
2Adaptability or versatility
If conventional two-stage specular reflection technology is used in HUD, then the field of view can be widened, but the manufacturing and assembly cost increases due to strict tolerance requirements on concave lens
Solution Approach 1:
The patent employs standard spherical lenses in the lens array that can be manufactured with conventional tolerances, replacing the expensive custom-molded aspherical lenses required by conventional HUD systems. This approach significantly reduces manufacturing complexity and cost while achieving the desired optical performance.
Solution Approach 2:
The patent changes the optical parameters from requiring precise aspherical surfaces with strict tolerance to using standard spherical lenses with relaxed tolerance. By altering the lens geometry and optical path design, the system achieves the same field of view function with much easier and less expensive manufacturing processes.
3Reliability
If conventional HUD optical path is used, then image projection can be achieved, but ghost images are generated due to windshield reflections which affect imaging quality
Solution Approach 1:
The patent converts the harmful windshield reflection effect into a beneficial feature by designing the lens array to intentionally reflect light onto the windshield. This controlled reflection creates the desired virtual image display function while eliminating unwanted ghost images through precise optical path management.
Solution Approach 2:
The patent introduces the lens array as an intermediary optical element that mediates between the light source and the windshield. This intermediary controls and directs the light path, ensuring that reflections occur only at the intended display location rather than creating multiple ghost images, thereby improving overall imaging 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
The method improves imaging quality by reducing distortion and eliminating ghost images, resulting in a high-quality virtual image that enhances driver experience and safety, particularly in vehicles and aircraft.
Implementation Method 1
guiding a light beam corresponding to the output image to a display unit via a waveguide
Implementation Method 2
The waveguide is provided with at least one of an edge absorber for removing a ghost generated when the output image is projected onto the display unit
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed are an image processing method, an image display apparatus, a computer program product and an aircraft. The image processing method includes: generating a two-dimensional output image based on input information; guiding a light beam corresponding to the output image to a display unit; capturing a three-dimensional image displayed on the display unit; obtaining a photometric error and a geometric error between the captured three-dimensional image and the output image; constructing a loss function for the photometric error and the geometric error; solving the loss function through an algorithm for solving a point pair motion from three-dimension to two-dimension to obtain a translation matrix and a rotation matrix; and correcting the output image based on the translation matrix and the rotation matrix to display the corrected output image on the display unit.