Curvature measuring optical system in ophthalmometer - has lens groups with intermediate rotary prisms each deflecting section of beam

摘要

A curvature measuring optical system in an ophthalmometer comprises a first and a second lens group and rotary prisms disposed between the two lens groups. A light-intercepting member formed with at least three openings is disposed just behind the first lens group to divide the light beam between the two lens groups, and the rotary prisms are a first rotary prism member behind one of the openings to cause a light beam to be deflected on the focal plane in a predetermined direction and a second rotary prism member behind another opening to cause a light beam to be deflected on the focal plane in a perpendicular direction.