Method for determining centering data for working of optical glass in spectacle frames, requires taking at least one digital recording of the customer with matched spectacle frame, for display on image screen

摘要

A first raster line joins the lower or upper edges of the spectacles frame and two raster lines perpendicular to these are arranged outside and inside the edges of the disc-shape of a glass and a raster point for marking the null viewing point on the cornea reflex of the corresponding pupil, is shifted. For determining the null viewing point of this glass the spacing between the vertical raster lines is ascertained by computer and is compared with the previously inputted disc width and web/bridge width. From the conversion of the determined disc spacing of the vertical raster lines to the actual disc widths, a calibration ratio is calculated with which, by using the coordinates of the raster points, the horizontal actual position of the null viewing point of the glass, is determined.