Refractive-Index Resin Film for Hidden Display Pattern Visibility

The patent applies local quality by creating a resin layer with spatially varying refractive indices. The first area has a first refractive index, the second area has a second refractive index different from the first, and the third area has a third refractive index different from both. This local variation in optical properties allows different regions to perform different functions: enhancing pattern visibility where needed while minimizing light scattering in display areas.

The patent changes the refractive index parameter across different areas of the resin layer. By irradiating the resin layer with ultraviolet light through a mask, the refractive index is modified in specific regions (first area, second area, third area) to achieve the desired optical effects. This parameter change enables the resin layer to simultaneously provide pattern enhancement and reduce unwanted light scattering.

The resin layer is designed with local quality variations where different areas have different refractive indices. This allows the structure to maintain flat surfaces (avoiding step formation) while still achieving pattern enhancement through localized refractive index modulation rather than physical height differences.

The patent replaces the mechanical approach of creating physical steps or height differences with an optical approach using refractive index variation. Instead of forming actual steps that cause light scattering, the invention uses ultraviolet irradiation to create optical path differences through refractive index changes, thereby eliminating the harmful mechanical steps while maintaining the desired optical effects.