| 摘要 |
PURPOSE:To prevent the deterioration of the brightness due to the brightness saturation or the temperature rise, by employing terbium activated oxy-yttrium sulfide (Y1-xTbx)2O2S having predetermined Tb concentration x as the phosphor material of a projection type picture tube for green color. CONSTITUTION:The phosphor material layer of a projection type picture tube for green color is formed with a green phosphor light emission material such as terbium activated oxy-yttrium sulfide phosphor material shown by general formula (Y1-xTbx)2O2S where Tb concentration x is 3X10<-2=x<=6X10<-2>. When operating such picture tube with anode voltage of 28KV and the current density of 4muA/mm.<2> [Temperature 30 deg.C, (1) in the drawing] -10muA/mm.<2> [Temperature 80 deg.C (3) in the drawing], higher brightness than that of the conventional (Gd1-xTbx)2 O2S (Dushed line) is obtained and the deterioration of the brightness due to the temperature rise is reduced. |
