Rearview Mirror Rounded Substrate Grinding Contamination
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Solution Overview
Problem
Existing rearview mirror assemblies face challenges in maintaining the cleanliness of the transparent conductive layer on the front glass substrate during grinding and polishing, leading to contamination and potential defects in the electrochromic mirror reflective element.
Innovation Solution
A separate front rounded substrate is laminated or adhered to the electrochromic mirror reflective element, with its grinding and polishing done independently of the front glass substrate, thereby separating the processing steps and minimizing contamination, and allowing for a thinner, defect-free assembly with reduced waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If grinding and polishing is performed on the front glass substrate of the electrochromic mirror reflective element, then a rounded perimeter edge region is achieved, but contamination of the rear surface with transparent conductive layer occurs
Solution Approach 1:
The patent divides the mirror assembly into separate components: a front substrate and an electrochromic mirror reflective element. The front substrate is ground and polished separately to create the rounded perimeter edge region, while the electrochromic element with its transparent conductive layer remains uncontaminated. These components are then assembled together, allowing the rounded shape to be achieved without harming the sensitive conductive layer.
Solution Approach 2:
The patent extracts the grinding and polishing operation from the electrochromic mirror reflective element and applies it only to the front substrate. This separation removes the harmful contamination effect from the system while preserving the desired rounded perimeter edge region aesthetic and functional properties.
2Device complexity
If the front glass substrate is ground and polished together with the electrochromic mirror reflective element, then processing is simplified, but defects in the transparent conductive layer are introduced
Solution Approach 1:
The manufacturing process is segmented into separate stages: first, the front substrate is ground and polished to achieve the desired rounded perimeter edge region; second, the electrochromic mirror reflective element is assembled without contamination; third, the components are joined together. This segmentation prevents defects in the transparent conductive layer while achieving the required shape.
Solution Approach 2:
The front substrate is prepared with its rounded perimeter edge region through grinding and polishing before the electrochromic mirror reflective element is assembled. This preliminary action ensures that the shape is established beforehand, preventing any contamination or defects to the transparent conductive layer during the shaping process.
3Ease of manufacture
If a thicker front glass substrate is used to maintain structural integrity during grinding, then processing is easier, but the final assembly is thicker and more material is wasted
Solution Approach 1:
The patent separates the structural function (providing rounded perimeter edge region) from the electrochromic function. The front substrate can be optimized for structural integrity and rounded shape, while the electrochromic element provides the reflective functionality. This allows for more efficient material usage overall.
Solution Approach 2:
The patent changes the parameter of substrate thickness optimization from a single thick substrate to a combination of a thinner front substrate and a separate electrochromic element. This parameter change reduces overall material consumption while maintaining the structural integrity needed for grinding and polishing to achieve the rounded perimeter edge region.
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
This approach enhances processing efficiency, reduces waste, and ensures a smooth transition from the mirror casing to the reflective element, while maintaining the integrity of the transparent conductive layer and electrochromic medium, resulting in a more reliable and cost-effective mirror assembly with improved defect detection.
Implementation Method 1
a variable reflectance electro-optic (such as electrochromic) mirror reflective element
Implementation Method 2
the rear surface of the front glass substrate, which is coated with a transparent conductive layer
Data Source
AI summary
An interior rearview mirror assembly for a vehicle includes a mirror casing and a mirror reflective element having a first glass substrate and a second glass substrate with an electro-optic medium sandwiched therebetween and bounded by a perimeter seal. A front substrate has a rounded perimeter edge region that has a radius of curvature of at least 2.5 mm and that spans between a front side and a rear side of the front substrate. The rear side of the front substrate is adhesively attached at a first surface of the first glass substrate of the mirror reflective element. The rounded perimeter edge region of the front substrate is exterior the mirror casing and provides a smooth continuous transition between the front side of the front substrate and a side wall surface of the mirror casing.