| 摘要 |
A description is given of a method for selecting pre-framed spectacle glasses of minimum central thickness, which have been finished on two sides, which have a predetermined pane form. The method according to the invention is distinguished by the combination of the following features: - in a first step the horizontal line is determined which runs through the centre of a rectangle which surrounds the pane form and touches the pane form with each side at at least one point and whose sides are arranged horizontally and vertically, - in a second step the circle is determined which circumscribes the pane form and whose centre is on the horizontal line, - in a third step the centre thickness is selected in such a manner that it does not fall below the minimum edge thickness on the circle in the case of a predetermined position of the optical centring point. |
