Stylus for capacity change detection type disc system

A stylus for a capacity change detection type disc system for reproducing information signals from a track which is formed on a surface of a disc as a geometrical arrangement of pits corresponding to the information signals, comprising:

• a stylus body portion having a slide surface slidingly engageable with the track on the disc surface and made of a material which has the property that it is graphitizable when subjected to ion implantation;
• and
• an electrode portion provided on said stylus body portion having an intersecting relationship with said slide surface for detecting the information signals recorded on the track in the disc surface as a capacitance variation between the electrode portion and said pits and being formed integrally with said material of the stylus body portion by implantation of ions into said material, said electrode portion having graphitization concentrated most in the vicinity of the surface of said electrode portion and less concentrated in a portion remote from said surface and which varies continuously depthwise from said vicinity of said surface to said remote portion, said continuous depth-wise variation being obtained by implanting ions onto said stylus body portions and controlling the implantation by varying the ion acceleration voltage and the dose rate such that the approximated gradient of said continuous depth-wise variation is smaller than the approximated gradient which results from a single dose of implantation of ions.