Patent ID: 7991501

Claim:
A method of determining a work surface of a planar material for cutting a plate of a uniform thickness from a planar material, comprising the steps of: setting, with a surface plate of a measuring device as coordinates (X, Y), orthogonal coordinates (X, Y, Z) composed of the coordinates (X, Y) and a Z coordinate perpendicular to the coordinates (X, Y) on the surface plate, and mounting a planar material as an object to be measured on the surface plate; virtually configuring a plane ABCD that is parallel to the XY plane; setting the distance or height from the coordinates (X m , Y n ) of the virtual plane ABCD to the plate thickness center plane composed of midpoints of segments connecting an upper and lower surface of the planar material as the object to be measured as Z (m, n) , measuring Z (m, n) across the entire area of the planar material to be measured for m distances or heights in the X direction and n distances or heights in the Y direction while changing the coordinates (X, Y), and storing the measured data in a storage apparatus of a computer; seeking a maximum and minimum value of Z (m, n) for all coordinate points and calculating the difference thereof, and setting the obtained value as difference H(0.0, 0.0) when the measured value is not manipulated in any way; subsequently fixing end A of the virtual plane ABCD and respectively moving end B and end C vertically at a prescribed deflection width B, C regarding a predetermined maximum deflection width and pitch in the Z-axis direction so as to tilt the virtual plane ABCD against the surface plate on the computer; calculating the distance or height Z (m, n) (B, C) from all coordinate points (X m , Y n ) on the virtual plane ABCD to the plate thickness center plane of the coordinate points corresponding to the planar material each time the tilt is changed, and seeking the maximum and minimum value of Z (m, n) (B, C) and calculating the difference H(B, C) thereof; and repeating the calculation for all predetermined B and C combinations, and determining the virtual plane ABCD with the smallest value of H(B, C) calculated in all B and C combinations as a plane that is parallel to a plane of minimum machining cost.