| 摘要 |
PURPOSE:To realize a high landing tolerance by the minimum variation of pitch by arranging holes on a flat mask so that each line of holes extends parallel to the Y-axis, and so that the pitch of holes which are located at each diagonal end and are parallel to the Y-axis has a specified relation to the pitch of holes located on the Y-axis. CONSTITUTION:Perforating holes 2a on the Y-axis extend from the center (O) of the effective part of a mask, which corresponds to the center of a fluorescent screen, at pitch (ao). Holes 2a on the X-axis are located at every even number rank including the center (O) at pitch 3<1/2>a. The pitches of holes 2a arranged on each line parallel to the Y-axis become gradually smaller as they become apart from the X-axis. Each odd number rank is located in the middle of even number ranks. The holes 2a of each odd number rank extending along the Y-axis are positioned so that the hole number M of each odd number rank corresponds approximately to the mean point of the 4 holes, which are the hole numbers (M) and (M+1) of an even number rank and the hole numbers (M) and (M+1) of the next even number rank. As a result, a high landing tolerance can be realized with the minimum variation of pitch. |
