| 摘要 |
PURPOSE:To eliminate the uneven sheet thickness due to voltage waveform as a main cause by a method wherein the waveform and phase of voltage output, which is applied by a high-voltage generator to a discharge electrode, are variably controlled in synchronization with the change of the thickness of a produced sheet. CONSTITUTION:A discharge electrode 6 is held at high potential by being applied with high voltage generated by a high-voltage generator 5. The change of the thickness of the sheet in contact with a cooling roller is monitored with a thickness measuring apparatus 7 installed just after the point of contact of the sheet with the roller. Obtained thickness change waveform signal is sent to a waveform signal analyzer 7 so as to be analyzed in order to express the signal in terms of the sum of a plurality of sinusoidal waves. Control signals generating potential change to apply periodic waveforms, the frequencies and amplitudes of which are equal to and the phases of which are shifted 180 degrees to each of split up sinusoidal waves, are sent from the analyzer 8 to the high-voltage generator 5 in order to variably control the potential of the discharge electrode 6 as mentioned above. |
