Laser-Ablated Opaque Coating for Dead-Front Glass Display Windows
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Solution Overview
Problem
Existing glass or glass ceramic articles with opaque coatings struggle to create fine structures and windows that allow light from display elements to pass through while maintaining a homogeneous appearance, especially when display elements are switched off, due to difficulties in achieving congruent structuring and high setup costs with screen printing techniques.
Innovation Solution
A glass or glass ceramic article with a flat substrate and an opaque coating that allows light transmission of at most 5% in the visible spectral range, featuring a linear opening created by pulsed laser ablation with a width of up to 25 μm, which becomes visible only when a light source is activated, providing a 'dead front effect' by appearing opaque until illuminated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If screen printing is used to create fine structures and windows in opaque coatings, then the manufacturing process is simple and cost-effective, but the manufacturing precision and ability to create fine structures deteriorates
Solution Approach 1:
The patent replaces the mechanical screen printing process with a laser-based structuring method. The laser beam precisely removes coating material to create windows and fine structures, achieving manufacturing precision of at least 0.5 μm that is unattainable with screen printing, while maintaining ease of manufacture through direct digital control of the laser pattern.
Solution Approach 2:
The patent changes the fundamental parameter of how structures are created in the coating - from mechanical deposition and screening to laser-induced material removal. This parameter change enables precise control of window dimensions and positions, allowing creation of fine structures with widths of at least 0.5 μm that were previously impossible to achieve.
2Reliability
If multi-layer coatings are used with larger windows to ensure opacity, then the opacity is improved, but the visibility of display elements when illuminated deteriorates
Solution Approach 1:
The patent applies local quality by creating precisely sized windows (at least 0.5 μm wide) in the opaque coating at specific locations where display elements will be positioned. The coating maintains its opaque quality in all areas except these localized windows, ensuring both overall opacity and optimal display element visibility when illuminated.
3Adaptability or versatility
If screen printing is used for each new product design, then customization is achieved, but the setup costs and manufacturing time increase significantly
Solution Approach 1:
The patent replaces the physical screen manufacturing process with digital laser pattern control. Each new design can be implemented by simply changing the laser programming parameters, eliminating the need to manufacture new screens for each product variant. This enables rapid customization while maintaining high manufacturing efficiency and low setup costs.
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 achieves a visually inconspicuous opening that allows clear visibility of backlit display elements with high contrast, making the display elements appear larger due to diffraction effects, and enables precise control over brightness and heating level indication, addressing the challenge of creating a homogeneous and functional display.
Implementation Method 1
a pulsed laser beam is directed onto the opaque coating and the coating is locally removed by ablation up to the surface of the glass or glass-ceramic article and an opening is thus created in the opaque coating
Data Source
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AI summary
The aim of the invention is to achieve what is known as a "dead front effect", in which display elements or symbols to be displayed on a glass or glass-ceramic article are not visible to an operator when they are switched off. For this purpose, a glass or glass-ceramic article (1) is provided, with - a flat glass or glass-ceramic substrate (2) with two opposite side surfaces (20, 21), which - in the visible spectral range from 380 nm to 780 nm, has a light transmission τvis of at least 1 % for visible light which traverses the glass or glass-ceramic substrate (2) from one side surface (20, 21) to the opposite side surface (21, 20), wherein - a side surface (20, 21) of the glass or glass-ceramic substrate (2) is provided with an opaque coating (5) which has a light transmission τvis of at most 5% in the visible spectral range from 380 nm to 780 nm, and there is an opening (9) in the opaque coating (5) which allows the passage of on the surface of the coating (5) incident light allowed through the coating (5) and the glass or glass ceramic substrate, wherein the opening (9) on the glass or glass ceramic substrate (2) has a width (91) of at most 80 µm.