Compact Telephoto Optical Imaging System Using Folded Light Path

The patent introduces a reflective member (prism) that bends light paths in three-dimensional space, allowing the optical system to achieve a long effective focal length while maintaining a compact form factor. The light path is folded through multiple reflections, effectively utilizing spatial dimensions to resolve the contradiction between focal length and system size.

The optical system is divided into distinct functional groups: a first lens group with positive refractive power, a reflective member, and a second lens group with negative refractive power. This segmentation allows each component to be optimized independently for its specific function while working together to achieve the desired telephoto performance in a compact configuration.

The patent combines reflective surfaces directly onto the lens groups rather than using separate optical elements. The first lens group includes a first reflective surface and the second lens group includes a second reflective surface, merging the reflection function with the existing lens structure to minimize additional complexity.

The reflective member serves multiple functions: it bends light to achieve compact folding, provides additional optical path length for telephoto performance, and can be integrated with the lens groups to provide both reflection and refraction functions. This multi-functionality reduces the need for separate dedicated components.