Development of capacitance type micro encoder

Micro sensors are key devices for developing miniature sized micromachines which are topically required to be developed. In this paper, micro rotary and linear encoders using electrical capacitance and a signal processing circuit for the encoders are proposed. Capacitance change occurs according to the rotation of two micro discs whose surfaces are patterned by metal thin film. This type of micro encoder has the advantages of 1) easy micronization by using sputtering method and photolithography, 2) robust against electrical noise, 3) without temperature compensation. Trial productions were made and the characteristics were tested