Data display CRT having a white-emitting screen
AssigneeNorth American Philips Consumer Electronics Corp.
InventorsAnthony V. Gallaro, Robert A. Hedler
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Abstract
The invention provides an advantageous blend of green, orange and blue-emitting phosphors to constitute an improved white-emitting screen component in a data display CRT. The improved white-emitter evidences medium-long persistence and thereby provides flicker-free imagery when the tube is expeditiously employed in conjunction with field refresh rates of 20 to 40 Hz.
Claims8
A monochrome data display cathode ray tube having means for forming and directing an electron beam to impinge a cathodoluminescent screen evidencing medium-long image persistence disposed in the viewing area, such being constituted of a bright white-emitting screen component substantially defined by C.I.E. color coordinates having an "x" value in the order of 0.275.+-.0.015 and a "y" value in the order of 0.295.+-.0.010 and exhibiting a nominal color temperature in the order of 10,600.degree. K. (+18 MPCD), at substantially 15 KV, 50 ua excitation, said white-emitting screen component being formed of a discrete blend of phosphors comprising:
- a medium-long persistence green-emitting phosphor evidencing an excited hue substantially defined by C.I.E. color coordinates having an "x" value in the order of 0.210.+-.0.010 and a "y" value in the order of 0.700.+-.0.010;
- a medium-long persistence orange-emitting phosphor evidencing an excited hue substantially defined by C.I.E. color coordinates having an "x" value in the order of 0.550.+-.0.010 and a "y" value in the order of 0.440.+-.0.010;
- and
- a medium persistence blue-emitting phosphor exhibiting an excited hue substantially defined by C.I.E. color coordinates having an "x" value in the order of 0.145.+-.0.010 and a "y" value in the order of 0.060.+-.0.005.
A medium-long persistence white emitting cathodoluminescent phosphor component for use in a data display CRT screen, said component being a blend of phosphors substantially comprising:
- 60.+-.2 weight percent of orange-emitting CdSiO.sub.3 :Mn:As;
- 25.+-.2 weight percent of green-emitting Zn.sub.2 SiO.sub.4 :Mn:As;
- and 15.+-.2 weight percent of blue-emitting ZnS:Ag.
Dependencies are inferred from the claim text.