High-resolution variable focus lens having an extra-long back focal length with telecentric design

摘要

A high-resolution variable focus lens system that has an extra-long back focal length with a telecentric design. The lens system includes three groups of lenses between an object (screen) and an image (a liquid crystal panel). The first group of lenses, comprising three lenses and having a negative power, is used for focusing and zooming of the lens system. The second group of lenses, comprising two lenses and having also a negative power, is used for zooming of the lens system. The third group of lenses, comprising six lenses and having a positive power, is similarly used for zooming of the lens system.