NEEDLES FOR POSITIVE OR AC CORONA
Original Publication Date: 1980-Apr-30
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
Needle corona generating devices offer some potential advantages in xerographic applications. It has been observed, however, that it is difficult to obtain large positive or AC corona currents without sparking. It has been found that tip shape and size are important parameters in generating positive and AC corona. Needles with tapered shafts leading to rounded points are most desirable. Tip diameters below O.lOmm readily yield to sparking. Larger tips require higher voltage and do not offer any known advantages. Thus, for positive and low frequency AC corona the optimum tip diameter is in the range of 0.lOmm to 0.15mm.