Electro-optic Assembly Double Image Reduction
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Solution Overview
Problem
Existing electro-optic devices in heads-up displays face challenges in maintaining high contrast ratios and reducing double image effects in bright lighting conditions, particularly due to secondary reflections from substrates, which can cause blurry or unclear primary images.
Innovation Solution
A variable transmittance electro-optic assembly is designed with partially reflective and transmissive substrates, an electro-optic material, and low reflectance coatings on secondary surfaces, achieving a high double image ratio by optimizing the reflectance of transflector coatings and net reflectance, thereby minimizing double image effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional electro-optic devices use standard substrates without optimized coatings, then manufacturing is simpler, but double image effects occur due to secondary reflections from substrates
Solution Approach 1:
The patent applies low reflectance coatings on secondary surfaces (surfaces other than the principle transflector) to convert harmful secondary reflections into beneficial reduced reflections. By specifically targeting non-principle surfaces with low reflectance coatings, the patent eliminates double image effects while maintaining the overall device structure, thus converting the harmful reflection phenomenon into a beneficial outcome without requiring complete redesign of the system.
Solution Approach 2:
The patent implements different reflectance characteristics on different surfaces of the electro-optic device. The principle transflector maintains its standard reflective properties, while secondary surfaces are specifically treated with low reflectance coatings. This localized differentiation of surface properties allows the patent to eliminate double image effects from secondary reflections without affecting the primary optical function, resolving the contradiction between maintaining simple manufacturing and eliminating harmful effects.
2Illumination intensity
If high reflectance transflector coatings are used to improve image brightness, then contrast ratio improves, but secondary surface reflections increase causing double image
Solution Approach 1:
The patent allows the principle transflector to maintain high reflectance for optimal image brightness and contrast, while simultaneously applying low reflectance coatings on secondary surfaces to eliminate their harmful reflections. This selective approach converts the potential harm of high reflectance (which could cause secondary reflections) into a benefit by restricting high reflectance only to the principle surface where it is needed, while suppressing secondary reflections from other surfaces.
Solution Approach 2:
The patent creates a localized optical property distribution where the principle transflector surface has high reflectance for optimal image brightness, while secondary surfaces have low reflectance to minimize double image effects. This spatial differentiation of reflectance properties allows the system to achieve high contrast ratios without suffering from secondary reflection issues, as each surface is optimized for its specific functional role.
3Manufacturing precision
If low reflectance coatings are added to secondary surfaces to reduce double image, then image clarity improves, but manufacturing complexity increases
Solution Approach 1:
The patent addresses the manufacturing complexity by focusing low reflectance coating application only on secondary surfaces rather than all surfaces. This selective approach maintains image clarity by eliminating double image effects while minimizing the scope of additional manufacturing steps required, thus converting the potential harm of increased manufacturing complexity into a manageable process by limiting it to specific surfaces only.
4Reliability
If angle stabilized reflectance is implemented for p polarized light, then performance in bright lighting conditions improves, but device complexity increases
Solution Approach 1:
The patent implements angle stabilized reflectance specifically for p polarized light on the principle transflector surface, while maintaining standard properties on secondary surfaces. This localized optimization of polarization control on the principle surface improves reliability in bright lighting conditions without requiring complex polarization control mechanisms throughout the entire device, thus resolving the contradiction between improved performance and device complexity.
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 effectively enhances contrast ratios and reduces double image issues, ensuring clear and bright image visibility in varying lighting conditions by controlling transmittance and reflectance levels, thereby improving the overall performance of heads-up displays.
Implementation Method 1
A principle transflector having a transflector coating on at least one of first and second surfaces
Implementation Method 2
Low reflectance coatings are disposed on secondary surfaces of the variable transmittance electro-optic assembly
Implementation Method 3
An electro-optic material is positioned between the second surface and the third surface
Data Source
AI summary
A variable transmittance electro-optic assembly includes a first partially reflective, partially transmissive substrate defining first and second surfaces. A second partially reflective, partially transmissive substrate defines a third surface and a fourth surface. The first substrate and the second substrate are configured to be held in a parallel spaced apart relationship and sealed about a perimeter of the first and second substrates. An electro-optic material is positioned between the second surface and the third surface. The electro-optic assembly includes a principle transflector having a transflector coating on at least one of first and second surfaces. Low reflectance coatings are disposed on secondary surfaces of the variable transmittance electro-optic assembly. The electro-optic assembly has a high double image characteristic defined by a ratio of a reflectance of the transflector coating to a net reflectance of at least one of the secondary surfaces, and further wherein the ratio is greater than 50.