摘要 |
Disclosed herein is a method for detecting capacitance including: allowing an oscillator to output a plurality of time division oscillation frequencies according to the capacitance detected by a capacitance detection plate; counting the plurality of time division oscillation frequencies during a predetermined time period; and offsetting increasing and decreasing of the oscillation frequencies due to noise such that a count value becomes uniform over the predetermined time period. Even when external noise is applied, distortion of the oscillation frequency due to the external noise is minimized and the oscillation frequency varies depending on only the capacitance of the capacitance detection plate. Accordingly, it is possible to prevent an error due to the noise at the time of the detection of the capacitance. |