Reflective Coated Glass Stack for Mirror-Like Video Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flat screen video displays struggle to maintain a mirror-like appearance when not in use while ensuring a bright and sharp video image under high levels of natural light.
Innovation Solution
A method involving chemical vapor deposition of a first coating layer with a refractive index of 3.0 or more, typically elemental silicon, and a second coating layer with a refractive index of less than 1.6, typically silicon dioxide, on a glass substrate, to create a reflective coated glass article with a total visible light reflectance of 45% or more and transmittance of 40% or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflective coating is applied to conceal the video display when not in use, then the mirror-like appearance is improved, but the brightness and sharpness of the video image deteriorates under high natural light conditions
Solution Approach 1:
The reflective coating is divided into multiple distinct layers (first coating layer with high refractive index, second coating layer with low refractive index) deposited in sequence. This segmentation allows each layer to perform a specific optical function, collectively achieving both mirror-like appearance and acceptable video image quality under high light conditions
Solution Approach 2:
The patent optimizes specific parameters including the thickness of each coating layer (5-50 nm range), the refractive index contrast between layers (first layer ≥3.0, second layer <1.6), and the chemical composition (elemental silicon and silicon dioxide). These parameter changes enable the coating to achieve 45% or more visible light reflectance while maintaining video image brightness
2Illumination intensity
If the first coating layer is deposited at a thickness of 5-50 nm, then the reflectance is improved, but the deposition time and process complexity increase
Solution Approach 1:
The patent specifies a controlled thickness range of 5-50 nm for the first coating layer, optimizing this parameter to achieve the required 45% or more visible light reflectance. This precise parameter control ensures efficient deposition that balances reflectance performance with reasonable deposition time
Solution Approach 2:
The combination of first coating layer (elemental silicon, refractive index ≥3.0) and second coating layer (silicon dioxide, refractive index <1.6) creates a composite coating structure. This composite approach achieves high reflectance through constructive interference of light waves, reducing the total deposition time compared to using a single thick layer
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 coated glass article achieves a mirror-like appearance when not in use and allows a bright and sharp video image when in use, with high reflectance and low transmittance, enhancing visibility under various ambient light conditions.
Implementation Method 1
A first coating layer is deposited directly on the major surface of the glass substrate from a first gaseous mixture that comprises a silane compound and inert gas
Implementation Method 2
A second coating layer is deposited over the first coating layer from a second gaseous mixture that comprises a silane compound, a radical scavenger and molecular oxygen
Data Source
AI summary
A method of making a reflective coated glass article includes providing a glass substrate. A first gaseous mixture is formed. The first gaseous mixture includes a silane compound and inert gas. The first gaseous mixture is delivered to a location above a major surface of the glass substrate to deposit a first coating layer directly on the major surface of the glass substrate. The first coating layer is deposited at a thickness of 5-50 nm. A second gaseous mixture is formed. The second gaseous mixture includes a silane compound, a radical scavenger and molecular oxygen. The second gaseous mixture is delivered to a location above the first coating layer. A second coating layer is deposited at a thickness of 5-50 nm over the first coating layer. The coated glass article exhibits a total visible light reflectance (Illuminant D65, ten degree observer) of 45% or more from a coated side of the coated glass article.