| 摘要 |
<p>PURPOSE:To cancel the stray capacity and improve the sensitivity of a finger- touching type coordinate input device, by adding LC parallel resonators which resonate when no finger touches the finger-touching type coordinate input panel of the device. CONSTITUTION:When either one of X- and Y-directions is selected under a time shared condition by means of analog switches 8-1, 8-2, 9-1, and 9-2, it can be known from the output of an output terminal 13 that which position in this direction is touched with a finger. Since stray capacities exist in the analog switches and wiring and, therefore, the sensitivity of a touch sensor is lowered, LC parallel resonators 6 and 7 which resonate together with the above mentioned floating capacities when no finger touches a finger-touching type coordinate input panel 4 are provided in this invention. Because of the parallel resonators 6 and 7 which resonate to the frequency of a sine wave oscillator 1 including the stray capacities, decline in the sensitivity resulting from the existence of a stray capacity can be prevented.</p> |
