Photo-curable Resin Curing for Image Display Manufacturing
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Solution Overview
Problem
Conventional methods for manufacturing image display devices with a transparent protection member result in light scattering due to gaps between the liquid crystal display panel and the protection member, leading to reduced contrast and brightness, and can cause display defects from resin curing shrinkage and incomplete curing of light-shielding members.
Innovation Solution
A method involving a photo-curable resin composition with a thermal polymerization initiator is interposed between the light-shielding member and the base, where light and heat are applied to ensure complete curing, minimizing stress and deformation, and using a resin with a low curing shrinkage ratio and storage elastic modulus to reduce strain on the image display unit and protection member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap is provided between the liquid crystal display panel and the protection member using a spacer, then the surfaces are protected, but light scattering occurs resulting in reduced contrast and brightness
Solution Approach 1:
The patent removes the spacer component entirely and replaces the air gap with a resin layer that is cured in place. This extracts the problematic air interface that causes light scattering while maintaining the protective function through the cured resin structure.
Solution Approach 2:
The patent changes the physical state of the resin from liquid (uncured) to solid (cured) to transform the gap-filling material into a stable structural element. This phase change enables the resin to maintain protective spacing without creating light scattering interfaces.
2Manufacturing precision
If the gap is filled with photo-curable resin and cured with light, then the resin cures in light-transmissive areas, but the resin in areas with light-shielding members does not cure sufficiently
Solution Approach 1:
The patent divides the curing process into two distinct segments: first UV light curing for light-transmissive areas, then thermal curing for light-shielding areas. This segmentation allows each curing method to be optimized for its appropriate region, ensuring complete and uniform curing throughout.
Solution Approach 2:
The patent employs sequential curing actions - first UV irradiation, then heating. This periodic application of different curing mechanisms ensures that all areas of the resin receive appropriate curing treatment at different stages of the process.
3Ease of manufacture
If the resin is cured by UV light irradiation only, then the process is simple, but the resin in areas with light-shielding members remains uncured causing display defects
Solution Approach 1:
The curing process is segmented into UV irradiation for simple, quick curing of accessible areas, followed by thermal curing to complete the process in shielded areas. This maintains simplicity where possible while ensuring completeness where needed.
Solution Approach 2:
The UV irradiation is applied first as a preliminary curing step that handles the majority of the resin quickly and simply. The subsequent thermal curing then completes the process for remaining areas, maintaining overall process efficiency while ensuring completeness.
4Manufacturing precision
If the resin has high curing shrinkage ratio, then the resin cures completely, but stress during curing causes deformation of the liquid crystal display panel
Solution Approach 1:
The patent selects a resin with specifically controlled physical parameters - low curing shrinkage ratio and appropriate storage elastic modulus. This parameter optimization allows the resin to cure completely while minimizing stress and deformation of the panel.
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
This approach enables high-brightness, high-contrast image display without defects, provides improved impact resistance, and results in a thinner image display device by ensuring complete curing of the resin and minimizing strain on the components.
Implementation Method 1
a photo-curable resin composition is interposed between the light-shielding member and the base and is photo-cured to form a cured resin layer
Implementation Method 2
the curable resin composition containing the thermal polymerization initiator is heated
Data Source
Figure 1(a)~1(c)
Figure 2
Figure 3(a)~3(c)
AI summary
A method for manufacturing an image display device includes the step of forming a cured resin layer 15 by interposing a photo-curable resin composition between a base 2 including an image display unit such as a liquid crystal display panel 8 and a light-transmitting protection member 3 including a light-shielding member 5 and then photo-curing the photo-curable resin composition. In this method, a resin composition having a curing shrinkage ratio of 5% or less, yielding a cured product having a storage elastic modulus at 25°C of 1.0 x 107 Pa or less, and forming the cured resin layer having a light transmittance of 90% or more in the visible range is used as the photo-curable resin composition. The method further includes the step of interposing a curable resin composition 11 containing a thermal polymerization initiator at least between the light-shielding member 5 and the base 2 and heating the curable resin composition 11. In this manner, display defects caused by the deformation of the image display unit do not occur in manufacturing a thin image display device in which the resins are interposed between the image display unit and the protection unit including the light-shielding member. In addition, high-brightness and high-contrast display can be achieved, and the resin in the area where the light-shielding member is formed can be sufficiently cured.