| 摘要 |
PURPOSE:To improve the picture quality while removing border lines on the screen divided into plural sections in the vertical direction by electrically dividing a vertical focusing electrode in a flat display device into plural pieces in the horizontal direction and giving them proper potential respectively. CONSTITUTION:A flat display device is formed of a rear electrode 23, the linear cathode 24, a vertical focusing electrode 25, a vertical focusing electrode 25', which is electrically divided into three sections 25'a, 25'b and 25'c in the horizontal direction, a vertical deflection electrode 26, a control electrode 27, a horizontal focusing electrode 28, a horizontal focusing electrode 30 and a screen plate 31 while giving different kinds of potential to vertical focusing electrodes 25'a, 25'b and 25'c respectively in order to enable them to be regulated. Accordingly, by properly performing fine regulation of those kinds of potential, the generation of border lines on the screen caused by gaps of the positions to vertically reach the screen plate 31 due a curve or the like of each electrode can be checked thus improving the picture quality. |
