| 摘要 |
PURPOSE:To prevent any width variation of stripe images, which might be caused when a continuous phosphor stripe is formed on the inner surface of a panel by use of both a slit-type shadow mask and a linear light source, by adjusting the length of the light source to a given value. CONSTITUTION:A shadow mask plate 1 is provided with a plural number of slits 2, and bridges 3 which are located between the slits 2. When the length of a light source 5 is represented by (l), the length of the slit 2 is represented by (b), the distance between the source 5 and the plate 1 is represented by (p), and the distance between the plate 1 and a panel 4 is represented by (q), the complete shadow length (Ps) and the half shadow length (Pl) of the image are represented by the equations, Ps=¦b-(l-b)q/p¦and Pl=b+(l+b)q/p. The length (l) of the light source 5 is determined so that the relation of Ps+Pl=2nh in satisfied when (h) represents the pitch of the slit 2 and (n) represents a positive integer. As a result, the influence of shadows caused due to the bridges 3 of the plate 1 can be extinguished, and stripe images of even width can be obtained. |
