Cushman, Darby & Cushman
Wide-angle zoom lens system
 A wide-angle zoom lens system comprising a front negative lens group and rear positive lens group and arranged to be zoomed by varying the airspace between the front and rear lens groups and to minimize variation of aberrations to be caused at the time of zooming. 
Olympus Optical Co., Ltd.
G
G02B
inventional
Toru
Fujii