METHOD FOR COMPUTATION OF POSITION OF STYLUS ON TABLET DEVICE AND PEN INPUT-TYPE COMPUTER OR PORTABLE COMPUTER USING IT

摘要

PROBLEM TO BE SOLVED: To correct various errors and to calculate an accurate position of a stylus by preparing plural sensors where the signals are induced by the stylus and measuring the stylus absence signals for every sensor to built them into a calculating procedure. SOLUTION: The position of a stylus 6 is calculated on a tablet 3 containing plural sensors where the signals are induced by the stylus 6. In this calculation method, the stylus absence signals A to D are measured for every sensor and built into a calculating procedure. In other words, the signals A to D are read out of a multiplexer MUX only when the stylus 6 is not put on the tablet 3 and then corrected by the compensation signals. Then the denominators of computational expressions x=(A+B-C-D)/(A+B+C+D) and y=(A+ C-B-D)/(A+B+C+D) are corrected by the algebraic sum of correction absence signals. Furthermore, it is desirable to correct the numerators of those computational expressions based on the signals A to D.