Switchable Diffusers for Variable Depth Head-Up Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current head-up displays face challenges in providing a safe and robust viewing system with variable perceived depth, especially in direct view configurations, due to limited diffraction angles and exposure to laser radiation, which increases system complexity and cost.
Innovation Solution
A viewing device utilizing a plurality of switchable diffusers, controlled by a controller to display an object on one diffuser at a time, with each diffuser independently operating in either a scattering or transmissive mode, allowing for adjustable virtual image distance and reducing exposure to laser radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed diffuser is used in a head-up display system, then the structure is simple, but the perceived depth of displayed information cannot be varied
Solution Approach 1:
The single diffuser is segmented into multiple diffusers arranged at different distances from the projection optic. Each diffuser can be independently controlled to display the image at a specific depth position, enabling variable perceived depth while maintaining manageable system complexity through modular design
Solution Approach 2:
The diffusers are made dynamically switchable between different operational states (scattering and transmissive modes) through electronic control. This dynamic capability allows the system to vary the perceived depth of displayed information by selecting which diffuser is active, transforming a static system into an adaptable one
2Object-affected harmful factors
If direct view configuration is used, then the system is simple, but the viewer is exposed to laser radiation
Solution Approach 1:
Multiple diffusers serve as intermediary elements between the laser projection source and the viewer's eye. By positioning diffusers at different distances and controlling their scattering states, the system mediates the laser radiation to create virtual images at various depths while protecting the viewer from direct laser exposure through the scattering effect
Solution Approach 2:
The diffusers change their optical properties (from transmissive to scattering state) to control light propagation. This state change mechanism allows the system to manage laser radiation exposure by switching diffusers into scattering mode, which diffuses the laser light and reduces direct exposure to the viewer
3Area of stationary object
If limited diffraction angle is used, then the system is simple, but the viewing area is restricted
Solution Approach 1:
The system transitions from a two-dimensional projection problem to a three-dimensional solution by arranging diffusers at different distances along the optical axis. This dimensional approach creates multiple virtual image planes at different depths, expanding the effective viewing area and angle without requiring complex lateral optics
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 solution provides a safe, robust, and cost-effective method to vary the perceived depth of displayed information, enhancing the viewing experience while minimizing complexity and ensuring eye safety by using liquid crystal devices that can switch between scattering and transmissive states.
Implementation Method 1
a first diffuser positioned a first distance from the virtual projection optic; a second diffuser positioned a second distance from the virtual projection optic; Each diffuser is independently controlled to operate in either a display (e.g. scattering) mode or a non-display (e.g. transparent) mode
Implementation Method 2
the diffusers are liquid crystal devices which are switchable between a transmissive state in which they are effectively transparent to the projected light and a scattering state in which they display the object
Data Source
Figure 1
Figure 2
Figure 3
AI summary
There is provided an imaging device. The imaging device comprises a projection optic arranged to form a virtual image of an object. The imaging device further comprises a first diffuser positioned a first distance from the virtual projection optic and a second diffuser positioned a second distance from the virtual projection optic. The controller is arranged to control the first and second diffuser to make the real image visible on one of the diffusers.