| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for detecting the coordinates of a contact position capable of detecting a contact position with high accuracy by avoiding a decrease in the accuracy of detecting the contact position when a touch panel is touched. <P>SOLUTION: Using an error amplifier 9 and an amplitude detection circuit 10 in a single line, touch panel output signals outputted from the electrodes 2, 3, 4, 5 of a touch panel 1 are inputted as they are switched from one to another in a circulatory manner by means of a circulating type switch circuit 8. Also, based on temperature drift offset error signals updated at all times in a circulatory manner and on offset error signals held only when power is inputted or when a recorrection operation signal is given, the touch panel output signals outputted from the electrodes 2, 3, 4, 5 of the touch panel 1 are subjected to offset compensation so as to effectively reduce errors in the computation results of a coordinate computing circuit 53 due to the temperature drift offset signals caused by variations in circuit characteristic among detection channels, initial offsets, and temperature drifts. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
