Lens's centering error determining method, involves measuring displacement of energy center of gravity of image of blind on sensor during rotation of lens, and determining error of lens from value of displacement of centre of gravity

摘要

The method involves supporting a lens (100) on a lens retainer, and rotating the lens through a drive roller (216). A light source (220) is focused on a blind (224), and another blind (226) is arranged behind the formed blind in a light direction. An image-giving sensor (232) e.g. charge-coupled device camera, is arranged behind a third blind (230) in the direction. A displacement of an energy center of gravity of an image of the latter blind on the sensor is measured during the rotation of the lens, and a centering error of the lens is determined from the value of the displacement. An independent claim is also included for a device for determining a centering error of a lens through optical scanning of a lens surface.