Patent ID: 8378689

Claim:
An electrostatic sensor device comprising: a first sensor element and a second sensor element; a dielectric substrate material formed in two layers, a sensing hole which penetrates the dielectric substrate material from its upper surface to its lower surface, said first sensor element being receivable in said sensing hole; and wherein said first sensor element comprises a conductive zone that contains conductive material, and wherein said conductive zone contains portions that are covered by said conductive material and portions that are not covered by said conductive material; and said second sensor element comprising a first conducting ring disposed on an upper surface of said dielectric substrate and surrounding said sensing hole and second conducting ring disposed on a lower surface of said dielectric substrate and surrounding said sensing hole wherein said first sensor element and said second sensor are capable of producing variable responses that are proportional to said portions of said conductive zone that are covered by said conductive material in said sensing hole when said first sensor element is disposed at different positions in said sensing hole.