Five-Lens Optical Assembly with Positive-Negative Power Distribution

The patent applies parameter changes by precisely controlling the refractive powers, curvatures, and thicknesses of each lens element. Specific conditions are imposed on parameters such as the effective optical diameter ratio (0.10<D1/ALD<0.15), the focal length ratios, and the curvature radii to achieve optimal optical performance in a miniaturized configuration. This systematic parameter optimization allows the lens assembly to maintain high resolution while achieving a compact total length.

The patent resolves this contradiction by establishing a specific parameter range for the effective optical diameter ratio D1/ALD (0.10<ratio<0.15). This controlled parameter change ensures that the first lens maintains an appropriately sized effective optical diameter relative to the total assembly, preventing both excessive size and insufficient performance. The balanced parameter selection enables compact design while preserving optical quality.

The patent applies local quality by assigning specific functional characteristics to different lens elements. The first lens has positive refractive power with a convex object-side surface, the second lens has negative refractive power, the third lens has positive refractive power, and so on. Each lens element is optimized with specific curvature radii and thicknesses to address particular aberration types. This localized functional differentiation enables effective aberration correction while maintaining a relatively simple overall five-element structure.