Vehicle Head-Up Display Combining Polarization Filter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Combiner head-up displays in vehicles suffer from undesired reflections on the windscreen due to light-transmissive properties, which can negatively affect the viewer's visual impression by overlaying the displayed information.
Innovation Solution
A head-up display with a combiner screen and a polarization filter attached to its rear side, which filters out polarized light reflections from the windscreen, preventing disturbing reflections from passing through and improving visibility of the displayed information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a combiner screen is used to reflect the image to the viewer, then the viewer can perceive the image as an imaginary image behind the combiner screen, but the light-transmissive property of the combiner screen allows undesired reflections on the windscreen to pass through, negatively affecting the visual impression
Solution Approach 1:
A polarization filter is introduced as an intermediary element between the windscreen and the combiner screen. This filter selectively blocks polarized light from windscreen reflections while allowing non-polarized light from the head-up display image to pass through, thereby mediating between the conflicting requirements of image transmission and reflection suppression
Solution Approach 2:
The solution changes the optical parameter of the light by using a polarization filter that exploits the polarization state of reflected light. Windscreen reflections are polarized due to the angle of incidence, and the filter selectively blocks this polarized component while maintaining transmission of the display image, thus changing how light interacts with the system
2Ease of operation
If the combiner screen is made light-transmissive to allow viewing through it, then the viewer can see the situation outside the vehicle, but undesired reflections from the windscreen can also pass through and overlay the displayed information
Solution Approach 1:
The polarization filter serves as a selective intermediary that distinguishes between desired light (from the head-up display) and undesired light (windscreen reflections) based on their polarization states, allowing the combiner screen to remain light-transmissive while blocking only the harmful reflected light
Solution Approach 2:
The solution converts the harmful polarized windscreen reflections into a beneficial filtering mechanism. By exploiting the polarization property of reflected light, the system uses the very characteristic that causes the problem (polarization of reflections) as the basis for eliminating it, while preserving the light-transmissive viewing function
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
Significantly enhances the visibility and perceptibility of the information displayed by eliminating or reducing unwanted reflections, allowing the viewer to see the virtual image clearly without interference from windscreen reflections.
Implementation Method 1
a polarization filter is attached to a rear side, which is remote from the viewer, of the reflection surface of the combiner screen
Data Source
AI summary
The disclosure relates to a head-up display for a vehicle. The head-up display includes a combiner screen that is arranged between a viewer and a window pane of the vehicle. The combiner screen reflects an image, which is generated by an image generating and imaging device at a front-side reflection surface, which faces the viewer, to the viewer. The viewer can perceive the generated image as an imaginary image located behind the combiner screen. A polarization filter is attached on a rearward side, which is remote from the viewer, of the reflection surface of the combiner screen.