| 摘要 |
PURPOSE:To simplify the process of manufacture for mask framework by forming an acute angle at the bottom edge of the mask framework only by punching and folding processes along the axial direction of tube. CONSTITUTION:A framework body 10, consisting of the bottom peripheral side 102 formed at almost right angle to the side wall portion 101, the inclined portion 103 formed at angle of almost 45 deg. along the side wall portion 101, and the bottom portion 105 formed in almost parallel with the bottom peripheral side 102, is prepared. Then, the inclined portion 103 is punched by moving the punching tool 11 in the parallel direction with the axle of tube, and then part of the inclined portion 103 is folded by applying a parallel force with the axle of tube so that it is almost parallelized with the bottom peripheral side 102 and the folded portion 104 is arranged at almost right angle to the axle of tube. The edge 103', having an inclined angle of approx. 45 deg., takes a shape projecting toward the axle of tube and therefore eliminates the occurrence of scattered electron. |
