Light Control Film Groove Geometry for Filling and Scratch Reduction

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Solution Overview

Problem

Conventional light control films face issues such as surface scratches, bending of grooves during formation, and the white line phenomenon due to narrow groove entrances, which affect the filling of light absorbing materials.

Innovation Solution

A light control film manufacturing apparatus with a pattern formation mold that forms a bent portion in the groove portion, featuring intersecting lines with specific angles and spacings to reduce bending and scratches, and ensures proper filling of the light absorbing material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the groove portion is made thin and slim to achieve high aspect and aperture ratios, then the light control performance is improved, but the groove shape bends during formation and surface scratches occur on the mold

Engineering Contradiction:
Improvegroove shape accuracyVSAvoidmold surface integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The pattern formation structure incorporates a bent portion with a curved cross-section consisting of first and second intersecting lines. This curved geometry allows the groove to be formed without sharp corners that would concentrate stress and cause bending, while the curvature radii are controlled to prevent mold surface scratches during the forming process

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention optimizes specific geometric parameters including the first intersecting angle (α) between 80° to 100°, the second intersecting angle (β) smaller than α, the length of the first intersecting line (1μm to 5μm), and the curvature radii (R1 and R2) of the bent portion. These parameter changes enable the groove to maintain its shape during formation while achieving high aspect and aperture ratios

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the groove entrance is narrowed to achieve high aspect ratio, then the light control performance is improved, but the light absorbing material cannot be properly filled, causing white line phenomenon

Engineering Contradiction:
Improvelight control performanceVSAvoidlight absorbing material filling
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The bent portion with curved cross-section and controlled curvature radii (R1 and R2) creates a gradual transition in the groove geometry. This curved structure prevents sharp corners that would trap air or prevent material flow, allowing the light absorbing material to be properly filled even in narrow grooves while maintaining high aspect ratio

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention optimizes the intersecting angles (α and β) and the length of the first intersecting line to create a groove geometry that balances narrow entrance for high aspect ratio with sufficient opening for material filling. The curved cross-section parameters are specifically designed to enable complete material infiltration

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4091804B1Light control film manufacturing apparatus and light control film manufactured by same
Publication Date: 2025.12.03 LG CHEM LTD
  • EP4091804B1 patent drawingFigure 1
  • EP4091804B1 patent drawingFigure 2
  • EP4091804B1 patent drawingFigure 3

AI summary

The light control film manufacturing apparatus according to an example of the present invention comprises: a film supply device for supplying a base film; and a pattern formation mold for applying pressure onto one side of the base film to form a pattern thereon, wherein the pattern formation mold comprises a main body and a pattern formation structure protruding from the outer surface of the main body and extending in a first direction, where in the pattern formation structure, a cross-section perpendicular to the first direction may include: a pair of first intersecting lines, one ends of which are connected to the main body, having a first intersecting angle; and a pair of second intersecting lines extending from the other ends of the pair of first intersecting lines, respectively and having a second intersecting angle smaller than the first intersecting angle.