Variable focal length lens system for e.g. camera, has two sets of fixed lenses , and another two sets of lenses displaceable to be positioned between variable wide angle lens focal position and variable telephone lens focal position

摘要

The system has three sets of lenses (110, 130, 140) formed in a single block, where two lens sets (110, 140) are fixed. Two sets of lenses (120, 130) are displaceable to be selectively positioned between a variable wide angle lens focal position and a variable telephoto lens focal position to change the focal distance, where the lenses are made of positive or negative refraction power. The lens set (130) is adjusted in a fine manner for focusing on an object, when the object is positioned at different distances.