Six-Lens Camera System for Near-Infrared Driver Monitoring

The patent divides the optical system into six separate lens elements (L1-L6) with alternating positive and negative refractive powers. This segmentation allows each lens to be optimized for specific functions: L1 and L3 for near-infrared correction, L2 and L4 for FNO brightness enhancement, and L5-L6 for additional optical optimization. The division into more elements enables simultaneous achievement of both near-infrared optical characteristics and bright FNO.

Each lens element is designed with specific local properties: L1 and L3 have positive refractive power optimized for near-infrared light, while L2 and L4 have negative refractive power configured to enhance brightness. The patent applies different curvature radii, thicknesses, and refractive indices to each lens based on its position and function, allowing localized optimization that collectively achieves both near-infrared performance and bright FNO.

The patent combines multiple functions into the six-lens system: near-infrared correction, FNO brightness enhancement, and aberration control are all integrated into a single compact optical assembly. The lenses are arranged in a specific sequence with controlled air gaps, merging what could be separate optical modules into one unified system that achieves multiple objectives without proportionally increasing complexity.

The patent employs aspherical surfaces on multiple lens elements to reduce the number of components needed for aberration correction. By using curved surfaces with varying radii (R1-R12) and aspherical coefficients, the design achieves complex optical functions with simpler individual lens elements, offsetting the complexity increase from adding two more lenses to the four-lens baseline.