Determination method and processing method of machined surface of plate-like material, and apparatus for use in said methods

An apparatus for determining a machined surface of a plate-like material capable of minimizing machining margin upon machining the plate-like material with two- or three-dimensional deformation to realize a uniform thickness, comprising:

• a surface plate on which the plate-like material is supported as an object to be measured, a distance sensor retained a height from said surface plate, and a computer receiving data measured by said distance sensor and having a recording device;
• said surface plate having a surface defining coordinates (X,Y) used to define orthogonal coordinates (X,Y,Z) formed from a Z coordinate that is perpendicular to the coordinates (X,Y) on the surface plate, and said computer having software stored on a computer storage medium for virtually configuring a plane ABCD that is parallel to the XY plane in which a distance from the surface plate is H;
• said distance sensor being arranged to measure a distance (height) Zm,n from coordinates (Xm, Yn) of the virtual plane ABCD to coordinates (Xm, Yn) of an upper surface of the plate-like material as an object to be measured m times in the X direction and n times in the Y direction while changing the coordinates (X, Y) for all areas of the plate-like material, and the measured data being stored in said recording device of the computer;
• said software for searching for a maximum value and a minimum value of Zm,n regarding all coordinate points and calculating the difference thereof and setting the value as difference H 0.0, 0.0 when no inclination operation is performed on the virtual plane ABCD;
• subsequently regarding a maximum fluctuation width and pitch predetermined in the Z axis direction, said software for inclining the virtual plane ABCD against the surface plate by fixing end A of the virtual plane ABCD and respectively raising and lowering end C and end B at prescribed fluctuation widths B, C;
• said software for calculating a distance (height) (Zm,n) B, C from all coordinate points (Xm,Yn) on the virtual plane ABCD to the corresponding coordinate point of the upper surface of the plate-like material each time the inclination is changed, searching for the maximum value and the minimum value of (Zm,n) B, C and calculating the difference H (B,C) thereof and repeating the search for all combinations of B and C in advance;
• wherein the smallest value of H(B,C) is determined to be a parallel plane of a plane in which the virtual plane ABCD will be of a minimum machining margin.