| 摘要 |
PURPOSE:To obtain a printing partofmance with a stabilized quality with any desired standard by controlling in such a way that, voltage or current of positive side in an alternating wave form is maintained constant and voltage and current of negative side is controlled on a lightness on the surface of aluminium plate and providing the secondary roughening. CONSTITUTION:In an electrolyte both an aluminium plate subjected to the primary surface roughening is immersed, voltage or current for an anode is maintained constant and diameter and depth of pit are controlled by adjusting voltage and current for a cathode. Primarily, on the surface of aluminium plate, along its breadths lightnesses are measured and plotted. Next, after controlling voltage or current for a cathode, the lightnesses are measured again. Repeating these procedures if necessary, voltage and current are so controlled that the lightness comes in the specified range. A 1:1 correspondence exists between grain pattern formed by the secondary roughening process and lightness and when the lightness is maintained constant, a constant grain pattern is available for a constant printing performance. |
