| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To mitigate a time and energy necessary for normally detecting that human hands brought into contact with or approaching a data input device (mouse) exist. <P>SOLUTION: Electrostatic capacitive sensing is carried out by detecting a relative change in the capacity of a scoop capacitor formed by a conductor and the ground plane of a periphery. Charge is moved between the scoop capacitor and a bucket capacitor, and a voltage of the bucket capacitor is applied on an input threshold switch. State transition of the input threshold switch is detected, and a touch value (Touch Val) indicating the number of cycles of charge movement necessary for inducing the state transition is determined. The presence of an object brought into contact with or approaching the device is found by comparing the touch value with a prescribed threshold (Touch Off). At first, the bucket capacitor is charged up to a repeatable non-zero reference level to approach a charge level inducing the state transition. <P>COPYRIGHT: (C)2004,JPO</p> |
