Planar Nano-Photonic Microlens Array for Optical Sensor Edge Sensitivity

The patent applies local quality by implementing different microlens structures at different locations on the sensor. Specifically, the microlens curvature radius is varied across the sensor surface, with larger curvature radii at the edge regions and smaller curvature radii at the center regions. This local differentiation allows each region to be optimized for its specific chief ray angle conditions, maintaining pixel sensitivity at the edges while preserving overall sensor miniaturization.

The patent implements local quality through position-dependent microlens design where the curvature radius varies across the sensor surface. Edge-region microlenses have larger curvature radii that are better suited for handling oblique incident light with high chief ray angles, while center-region microlenses have smaller curvature radii optimized for near-normal incident light. This local optimization ensures effective light condensation across the entire sensor surface, preventing dark edges while maintaining overall illumination efficiency.

The patent applies preliminary action by optically compensating for edge darkening before the light reaches the photosensitive pixels. The variable-curvature microlenses pre-adjust the light paths and condense light onto the photosensitive cells before detection, ensuring that the photosensitive elements receive sufficient light intensity across the entire sensor surface. This optical pre-compensation eliminates the need for complex post-processing algorithms, thereby maintaining image quality while reducing processing complexity.