DISPLACEMENT SENSOR, PUSH-IN AMOUNT DETECTION SENSOR, AND TOUCH TYPE DEVICE

摘要

A push-in amount detection sensor includes a piezoelectric film, an electrode-formed protective film, and an adhesive layer. The electrode-formed protective film adheres to the piezoelectric film with the adhesive layer interposed therebetween such that an electrode is located on the side of the piezoelectric film. Relative permittivity ∈a of the adhesive layer is higher than relative permittivity ∈p of the piezoelectric film. Preferably an electrostatic capacitance per unit area of the adhesive layer is higher than an electrostatic capacitance per unit area of the piezoelectric film, more preferably the electrostatic capacitance per unit area of the adhesive layer is substantially double the electrostatic capacitance per unit area of the piezoelectric film. The thickness of the adhesive layer is set within a predetermined thickness range.

主权项

1. A displacement sensor comprising:
a piezoelectric film that generates an electric charge based on a displacement amount of the piezoelectric film; an adhesive layer disposed above a first surface of the piezoelectric film; and an electrode disposed above the adhesive layer opposite the piezoelectric film, wherein the adhesive layer comprises a permittivity greater than a permittivity of the piezoelectric film.