Patent ID: 7705612

Claim:
A capacitance type sensor characterized in that the sensor comprises: a substrate; a detective member opposed to the substrate; a conductive member disposed between the substrate and the detective member with being kept in an insulating state so that the conductive member can be displaced in the same direction as the detective member when the detective member is displaced perpendicularly to the substrate; a first capacitance electrode formed on the substrate so as to cooperate with the conductive member to form a first capacitance element; a second capacitance electrode formed on the substrate so as to cooperate with the conductive member to form a second capacitance element; a plurality of first switch electrodes disposed so as to be distant from the conductive member and kept at a ground potential; and a plurality of second switch electrodes disposed so as to be distant from the conductive member and cooperate with the respective first switch electrodes to make pairs, and kept at a potential different from the ground potential, the conductive member can be displaced toward the first and second capacitance electrodes with displacement of the detective member, and come into contact with a plurality of pairs of first and second switch electrodes, the displacement of a portion of the detective member corresponding to the first capacitance electrode can be detected on the basis of detection of a change in the capacitance value of the first capacitance element due to a change in the distance between the conductive member and the first capacitance electrode, by using only a signal input to the first capacitance electrode, when the conductive member is not in contact with at least one of the plurality of pairs of first and second switch electrodes, and the displacement of a portion of the detective member corresponding to the second capacitance electrode can be detected on the basis of detection of a change in the capacitance value of the second capacitance element due to a change in the distance between the conductive member and the second capacitance electrode, by using only a signal input to the second capacitance electrode, when the conductive member is in contact with all of the plurality of pairs of first and second switch electrodes.