Character recognition apparatus

Claim 1

A character recognition apparatus in which character,, numeral or mark (hereafter described as character) is recognized by detecting position of stylus pen for writing on a tablet with detection means of its position in terms of three coordinate axes of X, Y and Z comprising: detection circuit means (5, 6, 7) for detecting the initiation and completion of the movement of said pen (3) for writing one character by detecting change of the position of said pen (3) on the vertical coordinate axis (z) to the surface of said tablet (1) and by detecting deviation of the position on Z axis and by comparing the difference of the two pen positions on the plane axis (X and Y plane) before and after the change of the pen position; character size nomalizing circuit means (9) for making sizes of written characters uniform by processing data on the pen positions on the plane (X and Y plane) according to the following equations: where A is the maximum shift of said pen (3) on the X-coordinate axis and B is that of said pen (3) on the Y-coordinate axis, C is a desired size of character after normalization, Xt, Yt are coordinates of said pen (3) position on the axes of X and Y, respectively, Xmin, Ymin are the minimum value of the position of said pen (3) for writing one character on the X and Y axes, respectively, and X' and Y' are transformed coordinates after the normalization; calculating circuit means for the gradient & and the length L of a line segment in a stroke of a character by processing data on the pen position upon writing according to the following equation: where X' t , X' t-1 are transformed X-coordinates taken at the time t, and t-l,respectively, and Y' t . Y' t-1 are also transformed Y-coordinates taken at times T and t-1; determination means for extracting destinction of a stroke of a character by order of occurrence of θ and L of line segment(s) of a stroke; character recognition circuit means for recognizing character by combination in terms of the order of of occurrence of the distinctions of strokes.