Glass-Ceramic Scattering Layer for Homogeneous Display Illumination

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Solution Overview

Problem

Glass or glass-ceramic cooking surfaces with integrated electro-optical display elements face challenges in visibility due to viewing angle dependency and optical wandering, especially when using punctiform light sources, leading to uneven illumination and distortion of display elements.

Innovation Solution

A glass or glass-ceramic element with a scattering layer containing 0.1% to 25% by weight of scattering particles and a polyester-modified, condensation-curing silicone resin on its underside, which reduces viewing angle dependency and provides homogeneous illumination, maintaining impact resistance and adhesion even under thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a scattering layer is added to improve visibility and reduce viewing angle dependency, then illumination homogeneity improves, but device complexity increases

Engineering Contradiction:
Improveillumination homogeneityVSAvoiddevice complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a scattering layer with specific local properties (particle size 200-800 nm, specific binder composition) only in the region where display element visibility needs improvement. This localized approach enhances illumination homogeneity in the critical viewing area without adding complexity to the entire glass ceramic structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The scattering layer is formed as a composite material combining inorganic scattering particles (200-800 nm diameter) with a polyester-modified condensation-curing silicone resin binder. This composite structure provides both the scattering function for homogeneous illumination and the adhesion/thermal stability required for cooking surface applications.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If the glass ceramic element has a nubbed underside for improved handling, then ease of operation improves, but manufacturing precision deteriorates due to light refraction distortion

Engineering Contradiction:
Improvehandling easeVSAvoiddisplay contour sharpness
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The scattering layer is applied locally to specific regions of the glass ceramic underside where display elements are located. This localized scattering compensates for the optical distortion caused by the nubbed underside structures, improving display contour sharpness in the critical display areas while preserving the ergonomic handling benefits of the nubbed design.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If punctiform light sources are used for display illumination, then power consumption decreases, but illumination homogeneity deteriorates causing separate light source perception

Engineering Contradiction:
Improvepower consumptionVSAvoidillumination homogeneity
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The scattering layer acts as an intermediary between the punctiform light sources and the viewer. It diffuses the light from discrete LED sources, transforming the light distribution pattern from spotted to homogeneous while maintaining the energy efficiency of using compact punctiform light sources in the first place.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Illumination intensity

If a scattering layer with high particle content is used to improve visibility, then illumination homogeneity improves, but impact resistance deteriorates

Engineering Contradiction:
Improveillumination homogeneityVSAvoidimpact resistance
Core Design Contradiction:
Illumination intensityVSStrength

Solution Approach 1:

The patent optimizes the particle content parameter within a specific range (0.1-25% by weight) to balance optical performance and mechanical strength. Additionally, the particle size is controlled (200-800 nm) and a specific binder type (polyester-modified condensation-curing silicone resin) is used to maintain adhesion and impact resistance while achieving sufficient scattering for homogeneous illumination.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The scattering layer uses a composite formulation with scattering particles dispersed in a polyester-modified condensation-curing silicone resin binder. This composite structure provides both the optical scattering function and the mechanical adhesion properties needed to maintain impact resistance, as the binder creates strong bonding between particles and to the glass ceramic substrate.

Inventive Principle:
Principle #40Composite materials

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 ensures improved visibility of electro-optical display elements with reduced optical wandering, maintaining homogeneous illumination and high impact resistance, while allowing for sufficient adhesion and thermal stability, achieving a haze value of over 95% and a minimum intensity to maximum intensity ratio greater than 0.95.

Implementation Method 1

a layer which has a content of scattering particles between 0.1% by weight and 25% by weight

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

a polyester-modified, condensation-curing silicone resin

Methodology Applied
Scientific EffectCondensation curing: Condensation

Data Source

PatentEP3222594B1Glass or glass-ceramic article, in particular with improved visibility for electro-optic display elements, and method for producing the same
Publication Date: 2020.04.29 SCHOTT AG
  • EP3222594B1 patent drawingFigure 1a~1c
  • EP3222594B1 patent drawingFigure 2a~2c
  • EP3222594B1 patent drawingFigure 3~4

AI summary

The invention relates to a glass or glass-ceramic element, in particular with improved visibility for electro-optical display elements (1) in at least one area (5). The glass or glass-ceramic element has an upper side (11) and an underside (12) and on the underside (12), at least in the region (5), in particular with improved visibility for electro-optical display elements, at least one layer (3) which Content of scattering particles between 0.1 and 25 wt. 6) of the glass or glass-ceramic element (1). A further aspect of the invention relates to a method for producing a glass or glass-ceramic element according to the invention.