Plasma CVD apparatus for making photoreceptor drum

Claim 1

A plasma CVD (chemical vapor deposition) apparatus of the capacitance coupling type defining a plasma discharge circuit for effecting the chemical vapor deposition on a drum surface for making a photoreceptor for use in an electrophotographic copying machine, said plasma CVD apparatus comprising: an air tight chamber made of electrically conductive material and connected to ground; a support provided in said chamber for supporting a drum inside said chamber insulated from said chamber; a shaft made of an electrically conductive material projecting from a wall of said chamber with a first end portion thereof located inside said chamber and a second end portion located outside said chamber, said drum being electrically connected to and fixedly supported by said first end portion; means for electrically insulating said shaft from said chamber; a source of RF power; a matching unit connecting said source of RF power to said shaft comprising a series connection of a capacitor and a first inductance element such that impedance of said RF power source matches on impedance of said plasma discharge circuit between said drum and said chamber; and a second inductance element connected between said shaft and ground thereby moderating a gradient of electric potential near said drum surface preventing positive ions from bombarding said drum surface, providing a smooth drum surface.