Multilayer Retroreflective Back Cover to Eliminate Waviness and Peeling

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Solution Overview

Problem

Existing glass back covers for terminal devices lack a retroreflective structure that provides high brightness and luxury aesthetics without non-reflective sections, waviness, lifting, or peeling, and require finer corner cube patterns that are indistinguishable to the naked eye.

Innovation Solution

A multilayer retroreflective structure for terminal devices comprising a shielding print layer, base layer, prism pattern layers, substrate layers, and cover layer, with specific spacing and bonding configurations to minimize non-reflective sections and enhance aesthetics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If corner cube patterns are applied to glass back covers for retroreflective effects, then brightness is improved, but non-reflective sections and waviness occur

Engineering Contradiction:
ImprovebrightnessVSAvoidnon-reflective sections
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the geometric parameters of the retroreflective structure by transitioning from corner cube patterns to micro prism patterns with optimized dimensions. The micro prisms have heights of 5-50 micrometers and base widths of 3-20 micrometers, creating a gradient structure that eliminates non-reflective sections while maintaining high brightness through optimized light reflection angles.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite retroreflective structure by integrating micro prism patterns directly into the glass back cover material itself, rather than applying separate corner cube pattern films. This composite approach ensures uniform optical properties throughout the glass, eliminating the non-reflective sections that occur at boundaries between the glass and applied retroreflective materials.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If finer corner cube patterns are applied for luxury aesthetics, then visual quality is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvepattern finenessVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical UV molding processes with a chemical etching method using fluorinated compounds. This substitution allows finer micro prism patterns to be created through chemical reactions rather than mechanical molding, achieving higher precision while simplifying the manufacturing process and reducing the need for complex soft molds.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the manufacturing approach from mechanical UV molding to chemical etching, allowing for finer pattern dimensions. The micro prism patterns with heights of 5-50 micrometers and base widths of 3-20 micrometers are achieved through controlled chemical etching parameters such as etchant concentration, temperature, and exposure time, which offer more precise control than mechanical molding.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If retroreflective films are applied to glass back covers, then brightness is improved, but lifting and peeling occur

Engineering Contradiction:
ImprovebrightnessVSAvoidbonding stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent merges the retroreflective function directly into the glass back cover by creating micro prism patterns within the glass material itself through chemical etching. This integration eliminates the separate retroreflective film layer, thereby eliminating the bonding interface that causes lifting and peeling, while maintaining high brightness through the embedded micro prism structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a composite structure where the retroreflective micro prism patterns are an integral part of the glass back cover material. The fluorinated compound treatment modifies the glass surface to create a stable, unified composite structure that eliminates the separation between adhesive layers and substrate, preventing lifting and peeling while maintaining optical performance.

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 multilayer retroreflective structure achieves high brightness and luxury aesthetics by minimizing non-reflective sections and eliminating waviness, lifting, and peeling, while maintaining fine prism patterns.

Implementation Method 1

A back cover including a retroreflective structure with no or decreased non-reflective sections

Methodology Applied
Scientific EffectRetroreflection: Retroreflector

Implementation Method 2

prism pattern layers, substrate layers, and adhesive layers

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4670962A1Back cover including multi-layer retro-reflective structure and terminal device
Publication Date: 2025.12.31 SAMSUNG ELECTRONICS CO LTD
  • EP4670962A1 patent drawingFigure 1
  • EP4670962A1 patent drawingFigure 2
  • EP4670962A1 patent drawingFigure 3

AI summary

The present disclosure relates to a terminal device including a multi-layer retro-reflective structure. According to one embodiment, a terminal device may include a housing and a back cover forming a rear surface of the housing, wherein the back cover includes: a shield print layer; a base layer disposed on the shield print layer; two or more prism pattern layers arranged on the base layer; one or two or more substrate layers bonded to at least one of the two or more prism pattern layers; and a cover layer disposed on the two or more prism pattern layers.