Arrangement for preventing discharge current flow between a rotary recording medium and a reproducing stylus in a rotary recording medium reproducing apparatus

Claim 1

An arrangement for preventing discharge current flow between a rotary recording medium and a reproducing stylus in a rotary recording medium reproducing apparatus, said rotary recording medium having recorded thereon an information signal as variations in electrostatic capacitance and being rotated for reproduction, said reproducing stylus making contact with and scanning over the recording surface of said rotary recording medium upon reproduction and having an electrode for detecting the information signal as variations in electrostatic capacitance said arrangement comprising: a reference potential member functioning as a reference potential point; a first direct-current connection path for connecting said rotary recording medium with said reference potential member for direct-current; and a second direct-current connection path for connecting said reproducing stylus with said reference potential member for direct-current said second direct-current connection path including a signal pickup circuit, said signal pickup circuit having a resonant line which includes a conductive frame, a trimmer capacitor, and a strip of conductor, said strip of conductor having one end coupled to said electrode of said reproducing stylus, and having another end coupled to said frame through said trimmer capacitor, said other end of said strip of conductor being also coupled to said frame through a coil which has an inductance large enough so that an impedance thereof is relatively high at an ultrahigh frequency.