Thin Image Display Resin Curing Method
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Solution Overview
Problem
Conventional liquid crystal display devices with a gap between the display panel and protection member suffer from light scattering, reduced contrast and brightness, and display defects due to resin curing shrinkage, and incomplete curing of photo-curable resin in areas with light-shielding members.
Innovation Solution
A method involving a curable resin composition with a curing shrinkage ratio of 5% or less and a storage elastic modulus of 1.0 x 10^7 Pa or less, interposed between the image display unit and protection member, ensuring minimal stress and complete curing of the resin, including direct UV irradiation to areas with light-shielding members.
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 surface is 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-filled continuous medium. This extracts the light-scattering interface (air-resin boundary) while maintaining the protective function, thereby improving brightness and contrast without sacrificing surface protection.
Solution Approach 2:
The patent changes the optical parameter of the medium filling the gap from air (refractive index ~1.0) to resin (refractive index ~1.5), matching the refractive index of the liquid crystal panel. This parameter change eliminates refraction and reflection at the interface, reducing light scattering while maintaining the protective gap structure.
2Manufacturing precision
If the gap is filled with photo-curable resin and light is irradiated to cure the resin, then the resin cures, but the light-shielding member blocks light from reaching areas where it is formed preventing complete curing
Solution Approach 1:
The patent adds a vertical irradiation dimension by providing light sources from both the upper and lower sides of the resin layer. This multi-dimensional lighting approach allows light to reach all areas of the resin including those blocked by the light-shielding member from a single side, ensuring complete curing without increasing horizontal structural complexity.
Solution Approach 2:
The patent positions the light-shielding member after resin application but before curing, and uses preliminary dual-side irradiation to ensure complete curing before final assembly. This sequencing allows the light-shielding member to remain in place during curing while still achieving complete resin polymerization through the combined light paths from both sides.
3Length of moving object
If the gap is filled with resin, then thickness is reduced, but stress during cure shrinkage causes deformation of the optical glass plates resulting in display defects
Solution Approach 1:
The patent changes the physical parameter of the resin by selecting materials with low shrinkage ratios (5% or less) and controlled elastic moduli. This parameter selection allows the resin to cure with minimal volume contraction, reducing stress on the optical glass plates and preventing deformation and display defects while maintaining the thin-profile benefit.
Solution Approach 2:
The patent employs resin materials with specific viscoelastic properties that allow gradual stress relaxation during curing. The resin's mechanical parameters are optimized to accommodate shrinkage without transmitting excessive stress to the rigid optical glass plates, thereby preventing display defects while achieving thinness.
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 minimizes strain on the display unit and protection member, achieving high-brightness, high-contrast images without defects, and provides a thinner, more impact-resistant display device with complete curing of the resin in all areas.
Implementation Method 1
a photo-curable resin composition is used as the curable resin composition interposed between the image display unit and the protection member, and is irradiated with rays of light
Data Source
Figure 1(a)~1(c)
Figure 2
Figure 3(a)~3(c)
AI summary
A thin image display device having a resin interposed between an image display unit and a protection member having a light-shielding member is manufactured. In the manufactured image display device, display defects caused by the deformation of the image display unit do not occur, and high-brightness and high-contrast display can be achieved. In addition, the resin in the area where the light-shielding member is formed can be sufficiently cured. The method for manufacturing an image display device includes the step of forming a cured resin layer by interposing a photo-curable resin composition between a base including the image display unit and a light-transmitting protection member including a light-shielding member 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 a visible range is used as the photo-curable resin composition. The photo-curable resin composition is photo-cured by irradiating it with rays of light at least from an outer side surface with respect to a forming surface of the light-shielding member.