| 摘要 |
PURPOSE:To prevent troubles occurring at the time of pick-off by forming alternately pick-off lines with linear and dotted perforated holes in a base plate. CONSTITUTION:Both negatives using a photosensitive film are formed in line for linear portion and also in dots or slots for chain-point portion. Using the negatives, the linear perforated holes 11, 13, 15... and the dotted perforated holes 12, 14,... are bored in the soft steel plate 10 to form pick-off lines. Thus, troubles such as local expansion, etc., occurring at the time of pick-off for flat mask can be prevented and its quality can therefore be raised. |
