Cushman, Darby & Cushman
Photographic lens system having a large aperture ratio
 A gauss type photographic lens system having a large aperture ratio which comprises five components of six lens elements and wherein symmetry of coma is improved and curvature of field, spherical aberration, etc., are favorably corrected by enlarging the airspace comprising a stop and increasing refractive indices of the lens elements arranged on both the sides of said stop. 
Olympus Optical Co., Ltd.
G
G02B
inventional
Toru
Fujii