Rollable Light Guide Back Sheet With Air-Blocking Adhesive Lines

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Solution Overview

Problem

Conventional light guide sheets face issues with separation between release paper and base film during storage in a roll form, leading to reduced adhesive strength and increased product defects due to air ingress, requiring high skill for attachment and detachment, and causing smearing of patterns.

Innovation Solution

A rollable back sheet with a base film and light guide pattern, featuring a line printing portion using adhesive ink to adhere to the release paper, preventing separation and maintaining adhesive strength, and a multi-layered structure for easy unrolling and attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the back sheet is stored in a roll form with release paper, then space is minimized and work efficiency is increased, but air flows into the gap between release paper and base film causing adhesive strength to lower and separation to occur

Engineering Contradiction:
Improvework efficiencyVSAvoidadhesive strength
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The adhesive layer is applied in advance during manufacturing before the sheet is rolled and stored. This preliminary application ensures that when the sheet is later unrolled and attached, the adhesive is already in position and ready to bond, preventing issues that would arise from delayed adhesive application

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A release paper is introduced as an intermediary protective layer between the adhesive-coated base film and the external environment during storage and handling. The release paper prevents contamination and maintains the adhesive layer's integrity until attachment time

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If workers attach and detach the light guide sheet manually, then pattern smearing can be avoided, but high skill is required and the process is time-consuming

Engineering Contradiction:
Improvepattern integrityVSAvoidattachment difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The back sheet is segmented into distinct functional layers: a base film providing structural support, an adhesive layer for bonding, and a light guide pattern layer for optical function. This segmentation allows each layer to be optimized independently and facilitates easier handling and attachment

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the base film is made thin for flexibility, then it is easy to roll and store, but it becomes difficult to unroll and spread without damage

Engineering Contradiction:
ImproverollabilityVSAvoidunrolling ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The base film is constructed as a composite material combining materials with different properties - one component provides flexibility and thinness for easy rolling, while another component provides tensile strength and dimensional stability for easy unrolling and spreading without damage

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 long-term storage and improved adhesive strength, allowing easy unrolling and attachment, reducing product defects and enhancing workability and quality by preventing pattern smearing and maintaining light guiding performance.

Implementation Method 1

a line printing portion that completely adheres the base film to the release paper

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

the base film is configured in a multi-layered structure so as to be easily unrolled and spread out

Methodology Applied
Scientific EffectLamination: Lamination

Data Source

PatentEP4071527B1Rollable back sheet for a light emitting device, and a light emitting device using same
Publication Date: 2026.02.18 EZ GRP INC
  • EP4071527B1 patent drawingFigure 1(A)~1(C)
  • EP4071527B1 patent drawingFigure 2(A)~2(D)
  • EP4071527B1 patent drawingFigure 3(A)~3(B)

AI summary

Proposed are a rollable back sheet for a light emitting device and a light emitting device using the same. More particularly, proposed are a rollable back sheet for a light emitting device and a light emitting device using the same, the rollable back sheet including a base film and a light guide pattern formed on the base film, and capable of blocking air from flowing into a gap between a release paper and the base film manufactured to have a line printing portion that completely adheres the base film to the release paper, thereby preventing the release paper and the base film from being separated from each other even when the base film is produced, distributed, stored, and used in a roll form and thus enabling long-term storage of the back sheet. In addition, when the base film is needed to be used in an unrolled form, the base film is easily unrolled and spread out due to the unique multi-layered structure thereof and thus is easy to cut and attach.