| CPC G06F 3/0418 (2013.01) [G06F 3/04164 (2019.05); G06F 3/044 (2013.01); G06F 2203/04107 (2013.01)] | 14 Claims |
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1. A capacitance detection device configured to detect a capacitance between a target and a detection electrode placed close to a shield electrode, the device comprising:
an alternating-current voltage output unit configured to output an alternating-current voltage to the shield electrodes through a plurality of first wires;
a first detection signal creation unit configured to have a plurality of detection nodes connected to a plurality of detection electrodes in one-to-one correspondence through a plurality of second wires, each of which is placed close to one of the plurality of first wires, to supply charge from a detection node, the detection node being one of the plurality of detection nodes, through a second wire, the second wire being one of the plurality of second wires, to a detection electrode, the detection electrode being one of the plurality of detection electrodes so that a voltage at the detection electrode vibrates according to the alternating-current voltage, and to create a plurality of first detection signals matching the charge supplied from the plurality of detection nodes;
an alternating-current output node from which the alternating-current voltage output unit outputs the alternating-current voltage;
a plurality of first paths, each of which branches from the alternating-current output node to one of the plurality of first wires;
a plurality of first filters disposed in the plurality of first paths; and
at least one phase difference signal creation unit configured to create a phase difference signal matching a phase difference between the alternating-current voltage and a first detection signal, the first detection signal being one of the plurality of first detection signals.
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