Optical Sheet Co-Extrusion Micro-Pattern Transcription
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Solution Overview
Problem
Conventional optical sheets for LCDs and lighting devices face challenges in mass productivity and cost due to difficulties in reproducing micro-patterns on thicker sheets, leading to poor commercialization and increased costs.
Innovation Solution
An optical sheet composed of a light-permeable resin with a pattern layer and a core layer, where the diffusion or light guiding pattern is formed on the pattern layer, and the core layer has higher viscosity, manufactured using a co-extrusion process, calendering, and cooling to enhance transcription rates and reduce production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If micro-patterns are reproduced on the surface of thick optical sheets using conventional methods, then the optical sheet can provide light diffusion or light guiding function, but the manufacturing process becomes complex and costly, reducing mass productivity
Solution Approach 1:
The patent combines the core layer and pattern layer into a single integrated optical sheet structure manufactured through co-extrusion. The pattern layer with micro-patterns is formed simultaneously with the core layer during the extrusion process, eliminating the need for separate secondary processing steps such as coating or surface processing. This integration resolves the contradiction by achieving high manufacturing precision while maintaining mass productivity through a streamlined, single-step manufacturing process.
Solution Approach 2:
The patent incorporates the micro-pattern formation into the initial extrusion process rather than applying it as a subsequent step. The pattern layer is extruded with pre-formed micro-patterns that are transferred to the core layer during the co-extrusion process. This preliminary action resolves the contradiction by establishing the optical function early in manufacturing, avoiding complex secondary processes and enabling high-volume production.
2Reliability
If secondary processes such as coating or surface processing are used to manufacture optical sheet patterns, then the optical sheet can achieve desired light diffusion or light guiding properties, but the manufacturing cost increases and productivity decreases
Solution Approach 1:
The patent merges the core layer and pattern layer manufacturing into a single co-extrusion process. The pattern layer with integrated micro-patterns is formed simultaneously with the core layer, eliminating the need for separate coating or surface processing steps. This integration resolves the contradiction by achieving reliable optical function through a simplified, single-step manufacturing process that reduces both cost and complexity.
3Ease of manufacture
If light scattering agents and additives are mixed with transparent resin to manufacture optical sheets, then the manufacturing process is simpler, but the ability to reproduce micro-patterns on thicker sheets is limited
Solution Approach 1:
The patent uses a composite structure consisting of a core layer and a pattern layer with different viscosities. The pattern layer contains the micro-patterns and is designed with specific viscosity characteristics that enable effective pattern transfer to the core layer during co-extrusion. This composite material approach resolves the contradiction by combining the manufacturing simplicity of extrusion with the precision of micro-pattern reproduction, overcoming the limitations of conventional mixing methods for thick sheets.
4Volume of moving object
If the volume and weight of the optical sheet increase, then the light diffusion or light guiding function is enhanced, but the sheet becomes harder to handle and mass productivity decreases
Solution Approach 1:
The patent combines the core layer and pattern layer into a single integrated structure manufactured through co-extrusion. This integration maintains the necessary volume for optical function while creating a unified, homogeneous structure that is easier to handle compared to multi-layer assemblies requiring separate processing. The simultaneous formation of both layers eliminates the need for additional handling steps, resolving the contradiction between volume enhancement and handling ease.
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 increases mass productivity and reduces costs by efficiently forming high-quality micro-patterns on the optical sheet, achieving high transcription rates and enabling the use of a broader range of resins, while also providing UV-blocking protection.
Implementation Method 1
the co-extrusion process continuously transports, pressurizes and melts the first and second raw materials in the main extruder and the co-extruder, respectively, by the difference in the relative velocity between a rotating screw and a barrel
Implementation Method 2
a calendering process that forms the diffusion or light guiding pattern, which diffuses lights, on the pattern layer by pressing said optical sheet using a calender roll
Implementation Method 3
a cooling process wherein said optical sheet with the diffusion or light guiding pattern formed on the pattern layer is cooled evenly by use of a guide roll
Data Source
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AI summary
An optical sheet and a method of manufacturing the same, and more specifically an optical sheet to use for back light units of Liquid Crystal Devices (LCD's), lighting devices of billboards and the like, and a method of manufacturing the same, is disclosed.