| 摘要 |
PROBLEM TO BE SOLVED: To provide an operation position detection device capable of increasing the frequency of a scan signal for detecting the operation position of an operation body which operates a capacitance type touch panel.SOLUTION: When a capacitance signal is applied to a capacitance sensor 12 disposed on a touch panel 10, a sensor voltage VM of the capacitance sensor 12 temporarily rises or lowers in accordance with the level of the scan signal, and then converges to a reference voltage Vref. When charging a capacitor 48 is started by the sensor voltage VM, the capacitor 48 is connected to one of constant current sources 50 and 52 in accordance with the switching of a switch 60, and the capacitor 48 is discharged. A scan signal generation part 32 generates the san signal whose signal width in an H level is lower than 1/2 of one cycle, and whose signal width in an L level is shorter than 1/2 of one cycle. When the scan signal is in the H level, a measurement part 36 measures time since charging/discharging the capacitor 48 is started until a voltage Vin of the capacitor 48 matches the reference voltage Vref. |
