Telephoto Lens Assembly with Segmented Groups for Compact Design

The optical lens assembly is divided into multiple lens groups (first lens group with positive refractive power, second lens group with negative refractive power, and third lens group with positive refractive power). Each lens group has specific functions and can be independently optimized, allowing the achievement of telephoto field of view with controlled overall size. The segmentation enables better control of optical path and reduction of total track length while maintaining high optical performance.

The patent employs a compact nested arrangement where lens groups are closely integrated along the optical axis. The first, second, and third lens groups are positioned in sequence with minimized spacing, creating a compact telephoto structure. This nesting approach allows the optical system to achieve long effective focal length (telephoto effect) while keeping the physical length compact, resolving the contradiction between telephoto performance and module size.

Each lens group is assigned specific local optical properties: the first lens group has positive refractive power for converging light, the second lens group has negative refractive power for diverging light to extend the optical path, and the third lens group has positive refractive power for final focusing. This local differentiation of optical properties allows the system to achieve telephoto field of view with controlled complexity, as each group performs a specific function rather than requiring all lenses to be complex.

The patent optimizes specific parameters of the lens groups including refractive powers, focal lengths, and spacing distances to satisfy particular mathematical relationships. By carefully controlling parameters such as the ratio of focal lengths and the distances between lens groups, the system achieves telephoto performance with minimized complexity. The parameter optimization allows the complex function of telephoto imaging to be achieved through coordinated simple elements rather than a single complex lens.