Patent ID: 7586731
Filing Date: 2009-09-08
Classification: H01T,H05F

Abstract:
1. A method of removing charges from a workpiece by applying positive and negative pulse-like high voltages to positive and negative electrode needles of an ionizer, thereby producing corona discharge to generate positive and negative ions in a charge removing area, and intermittently feeding the charged workpiece into said charge removing area by a conveying apparatus to remove the charges from said workpiece, the method comprising: measuring an ion balance inside the charge removing area by a surface potential sensor in the absence of the workpiece before said workpiece is fed into said charge removing area; changing a pulse width of a positive side or negative side pulse-like high voltage applied to said electrode needle depending on a measured result, thereby adjusting an amount of positive or negative ions generated from said electrode needle to maintain a previous balance between the positive and negative ions in the charge removing area; and then feeding said workpiece into said charge removing area to remove the charges from said workpiece.