Optical Film Protrusions for OLED Luminance Uniformity

The patent applies curvature by forming protrusions with rounded tops on the optical film surface instead of using a flat surface. These protrusions have a curved spherical cap structure that effectively controls light diffusion angles, improving luminance uniformity and color consistency across different viewing angles while maintaining manufacturing feasibility through injection molding or extrusion processes

The patent implements local quality by creating protrusions with specific geometric characteristics (height H, width W, and aspect ratio H/W ≥ 0.5) at specific locations on the optical film. The protrusions are arranged with a pitch of 5-50 μm and cover a density of 10-90%, creating localized light diffusion zones that enhance overall luminance uniformity without requiring the entire film structure to be complex

The patent optimizes the protrusion aspect ratio parameter (H/W) to be at least 0.5, which balances light diffusion effectiveness with manufacturing feasibility. The height H is controlled at 1-10 μm and width W at 2-20 μm, creating protrusions that provide sufficient light diffusion while being manufacturable using conventional injection molding or extrusion processes with standard tolerances

The patent uses a pitch of 5-50 μm between protrusions, which is sufficient to achieve the desired light diffusion effect without requiring excessively precise manufacturing. The protrusion density is controlled at 10-90% of the total surface area, providing adequate light diffusion coverage while allowing for manufacturing variations without compromising overall performance