Detection device

A detection device comprising:

• a detector including a plurality of first electrodes arranged in a predetermined direction and a plurality of second electrodes disposed around a detection region in which the first electrodes are disposed;
• a detection circuit configured to detect proximity of an external object to the detector based on electrical change at the first electrodes;
• a power circuit configured to generate a square wave based on electric power supply from outside;
• and
• a filter that is coupled to the power circuit through an isolator and configured to receive the square wave transmitted through the isolator, wherein
• the filter includes a low-pass filter circuit and a digital potentiometer,
• a periodically oscillating potential based on output from the filter is provided as a reference potential of the power circuit and provided to the second electrodes,
• a reference potential of the filter is a fixed potential,
• the power circuit is provided capable of changing the frequency of the generated square wave, and
• the filter is provided capable of changing the frequency of the periodically oscillating potential in accordance with an electric resistance value of the digital potentiometer.