Neutralization of electrostatic charges

Apparatus for regulating electrostatic charges on charge-retaining materials, comprising:

• a common electrical conductor;
• means for establishing an electrically conductive reference surface;
• a multiplicity of electrically conductive elongated bristles supported over said reference surface with one end of said bristles being in an electrically coupled relation to said common conductor, said bristles extending from their said one end toward said reference surface with the free ends of said bristles being adjacent said reference surface and with the positional relationship of said free ends approximating a row and column grid-like pattern;
• means for establishing a signal representative of the magnitude of the actual electrostatic charge level on a charge-retaining material;
• means for establishing a signal representative of the desired electrostatic charge level on said charge-retaining material;
• and
• a variable AC potential source whose output is determined by said actual and said desired electrostatic charge level signals, the output of said AC potential source being connected between said common electrical conductor and said reference surface for the purpose of producing an alternating electric field for neutralizing positive and negative electrostatic charges on charge-retaining material passed between the free end of said multiplicity of bristles and said reference surface such that said material is supported by said reference surface and is spaced a finite distance from said free bristle ends, the magnitude of said AC potential source being less than that required for the generation of corona.

A method of neutralizing positive and negative electrostatic charges on charge-retaining materials, comprising steps of:

• mounting a multiplicity of at least slightly conductive elongated bristles over a reference surface with one end of said bristles in an electrically coupled relation to a common conductor and the free ends thereof adjacent said reference surface, the positional relationship of the free ends of said bristles approximating a row and column grid-like pattern;
• connecting an AC potential source having a particular magnitude and frequency between said common electrical conductor and said reference surface to establish an alternating electrostatic field between the free ends of said bristles and said reference surface, said predetermined potential source magnitude being less than that required for the generation of corona;
• and
• moving a charge-retaining material through said alternating electrostatic field between said free bristle ends and said reference surface in contact with said reference surface but spaced a finite distance from said free bristle ends to thereby uniformly neutralize positive and negative electrostatic charges on said charge-retaining material.