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US4377768A
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Data display CRT having a white-emitting screen
Assignee: Philips North America LLC
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Filing: 1981-06-11
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Granted: 1983-03-22
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Expires: 2001-06-11
Abstract
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.
Inventors
- 👤 Anthony V. Gallaro
- 👤 Robert A. Hedler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:10
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/187
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
197 words
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° 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.
Claim 2
Dependent Claim
197 words
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° 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.
Claim 3
Dependent Claim
57 words
The monochrome data display cathode ray tube according to claim 1 wherein said green-emitting phosphor evidences a persistence of at least 32 milliseconds, said orange-emitting phosphor a persistence of at least 35 milliseconds, and said blue-emitting phosphor having a persistence of less than 1 millisecond, and wherein said white-emitting blend a persistence of at least 28 milliseconds.
Claim 4
Dependent Claim
46 words
The monochrome data display cathode ray tube according to claim 1 wherein the white-emitting cathodoluminescent screen component is a blend of phosphors evidencing persistence characteristics capable of producing a substantially flicker-free image display at scanning refresh rates substantially within the range of 20 to 40 Hz.
Claim 5
Dependent Claim
30 words
The monochrome data display cathode ray tube according to claim 1 wherein said green-emitting phosphor is a zinc orthosilicate host co-activated with manganese and arsenic (Zn 2 SiO 4 :Mn:As).
Claim 6
Dependent Claim
28 words
The monochrome data display cathode ray tube according to claim 1 wherein said orange-emitting phosphor is a cadmium silicate host co-activated with manganese and arsenic (CdSiO 3 :Mn:As).
Claim 7
Dependent Claim
24 words
The monochrome data display cathode ray tube according to claim 1 wherein said blue-emitting phosphor is a zinc sulfide host activated with silver (ZnS:Ag).
Claim 8
Dependent Claim
43 words
The monochrome data display cathode ray tube according to claim 1 wherein said blend of phosphors substantially comprises: 60±2 weight percent of orange-emitting CdSiO 3 :Mn:As, 25±2 weight percent of green-emitting Zn 2 SiO 4 :Mn:As and 15±2 weight percent of blue-emitting ZnS:Ag.
Claim 9
Independent Claim
50 words
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 3 :Mn:As; 25±2 weight percent of green-emitting Zn 2 SiO 4 :Mn:As; and 15±2 weight percent of blue-emitting ZnS:Ag.
Claim 10
Independent Claim
50 words
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 3 :Mn:As; 25±2 weight percent of green-emitting Zn 2 SiO 4 :Mn:As; and 15±2 weight percent of blue-emitting ZnS:Ag.
References Cited (Backward Citations)
US4151442A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-21 | 1986-09-20 | 1987-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-21 | 1990-09-20 | 1991-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-21 | 1994-09-20 | 1995-03-22 | $7700.00 | Window Closed / Lapsed |