Five-Lens Imaging System Shortening Total Length

The patent applies parameter changes by precisely controlling the refractive indices and curvature radii of each lens element. Specifically, it sets the refractive index of the first lens to 1.6-1.7 and the second lens to 1.5-1.6, while controlling curvature radii within specific ranges (e.g., first lens curvature between 0.5-2.0). These parameter optimizations enable the five-lens configuration to achieve high imaging performance while maintaining a compact total length of 3.5-4.5 times the focal length.

The patent utilizes curved surfaces with specific radius of curvature values for all lens elements. Each lens is designed with precise curvature parameters (e.g., first lens has curvature radii of 0.5-2.0 and 1.0-3.0, second lens has -1.0 to -3.0 and -0.5 to -2.0). These optimized curvatures enable effective aberration correction while maintaining a compact overall length, resolving the contradiction between imaging performance and total length.

The patent segments the optical system into five distinct lens elements with specific functions: the first lens (positive refractive power) for light gathering, the second lens (negative refractive power) for aberration correction, the third lens (positive refractive power) for focus control, the fourth lens (negative refractive power) for distortion correction, and the fifth lens (positive refractive power) for final image formation. This segmentation allows each lens to be optimized for its specific function, achieving high overall imaging performance while maintaining a compact total length.

The patent employs a composite optical system combining multiple lens materials with different refractive indices and dispersion characteristics. The first lens uses material with refractive index 1.6-1.7, the second lens uses 1.5-1.6, and subsequent lenses use appropriate materials for their specific functions. This composite approach enables effective correction of various optical aberrations across the entire field of view while maintaining a shortened total length.

The patent applies local quality by optimizing each lens element's parameters specifically for its function in the optical path. The first lens is optimized for light gathering with curvature 0.5-2.0, the second lens for aberration correction with negative curvature -1.0 to -3.0, the third lens for focus control, the fourth lens for distortion correction, and the fifth lens for final image formation. This localized optimization ensures high image quality across the entire field of view, meeting the stringent requirements of high-resolution imaging.

The patent replaces complex mechanical focus adjustment mechanisms with an optical design that achieves high resolution through precise optical parameter control. Instead of relying on mechanical focus tuning, the system uses optimized lens curvatures, refractive indices, and spacing to achieve diffraction-limited performance across the entire field of view, thereby meeting high-resolution requirements without complex mechanical systems.