| 摘要 |
PURPOSE:To decrease the circuit scale of the decoder by inputting a signal which indicates an X-axial direction and a signal which indicates a Y-axial direction and utilizing the two signals and the symmetry of coordinates. CONSTITUTION:The X and Y coordinates Pix and Pjx, and Piy and Pjy of two points Pi and Pj are inputted and an output signal showing the relation between the two points is decoded. In this case, the signal XDIR (0 for positive direction and 1 for negative direction) indicating the X-axial direction and the signal YDIR (0 for positive direction and 1 for negative direction) indicating the Y-axial direction are inputted and ANDed by an AND circuit 9 and EXORed by an EXOR circuit 10. An OR circuit 11 inputs plural output signals of a decoding circuit 1 and ORs all of them. |
