| 摘要 |
<p>1,227,677. Luminescent materials and uses thereof. RCA CORPORATION. 8 Aug., 1969 [9 Aug., 1968], No. 39832/69. Heading C4S, [Also in Division H1] A luminescent screen for a C.R.T. comprises red emitting, green emitting and blue emitting phosphor elements, the red phosphors being yttrium oxysulphide with europium activator, the green phosphors being zinc-sulphide or zinc-cadmium sulphide with copper and aluminium activators and the blue phosphors zinc sulphide with at least silver as activator. The green and preferred blue phosphors are substantially more resistant to Cu contamination. The C.R.T. may be of the focus grill, penetration, projection line sensing or shadow mask types with single or multiple guns, e.g. three. The elements may be produced by silk screening or photographic deposition and may be layers, lines or dots. The red emitting phosphors may be represented by (Y 1-a Eu a ) 2 O 2 S wherein a is 0À025 to 0À055. Eu may be present in the range 2À5 to 5À5 mol per cent of the Y+ Eu, e.g. 2À5 to 3À0 and 5À0 to 5À5. With 5 mol per cent Eu, the CIE co-ordinates are x = 0À675 and y = 0À325 and with 3 mol per cent Eu, = 0À663 and y = 0À337. Y 1À916 Eu 0À084 O 2 S is instanced. The green emitting phosphors may be represented by Zn 1-b Cd b S:Cu(x):Al(y) wherein b is 0À00 to 0À10, x and y are each 0À001 to 0À100 wt. per cent. A preferred phosphor is 0À928 ZnS.0À072 CdS:Cu(0À006 wt. per cent) :Al(0À006 wt. per cent). Persistences are 10 to 1000 microseconds and the CIE co-ordinates may be x = 0À311 and y = 0À601. In the blue emitting ZnS:Ag(y) phosphors, y may be 0À005 to 0À040 wt. per cent preferably 0À015. Preferably the blue phosphor is ZnS: Ag(z):M(c), wherein M is one of Mg, Ca, Sn and Ba, z is 0À015 to 0À040 wt. per cent and c is 0À02 to 2À00 wt. per cent. Preferably M is Mg, z = 0À030 and c = 0À35. Persistences are 10 to 1000 microseconds and the CIE co-ordinates x = 0À140 to 0À160 and y = 0À50 to 0À100. Mention is made of reduced X-radiation emission.</p> |
