METHOD AND APPARATUS FOR SETTING COORDINATE SYSTEM

摘要

A figure on a drawing DR placed on the read-out area TRA of a tablet is entered with a coordinate designating device by designating a plurality of points on the drawing, and at the same time a coordinate system of the figure is set and entered. To carry out the above coordinate setting, a first point Pt on the drawing DR is designated by the coordinate designating device to enter the coordinates of the first point Pt on a tablet coordinate system Xt-Yt, and coordinates of the designated first point Pt on an NC data coordinate system Xn-Yn are entered through a keyboard to set a reference point of the NC data coordinate system. A second point Pt min on a straight line passing through the first point Pt parallel to an X-axis or Y-axis of the NC data coordinate system Xn-Yn is designated by the coordinate designating device to enter the coordinates of the second point Pt min on the tablet coordinate system. The NC data coordinate system can be set and entered by employing the first and second points and the coordinates on the tablet coordinate system. An embodiment of the present invention may provide a method and apparatus for effecting the foregoing coordinate setting process. The reference point of the NC data coordinate system can easily be established, and it can be set and entered even when the reference point is located outside the read-out area of the tablet.