US4071640A
Expired / Lapsed
US
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Penetration phosphors for display devices
Assignee: Unisys Corp
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Filing: 1976-03-22
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Granted: 1978-01-31
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Expires: 1996-03-22
Abstract
Abstract La2O2S particles are employed as a carrier host in conjunction with terbium activator ions in a cathodo-luminescent penetration phosphor composition for cathode ray display tubes. A thin layer of La2O2SO4:Tb or La2O2SO4:Tb,Eu is utilized to provide a barrier which must be penetrated by excitation electrons to produce green spectral emission from the particle thereby increasing the voltage-turn-on characteristic of the phosphor. Additionally, methods are disclosed for synthesizing the same in addition to an improved method for synthesizing a penetration phosphor particle comprising a core of La2O2S:Tb and a barrier layer of La2O2S:Tb,Eu.
Inventors
- 👤 Stanley F. Ignasiak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:54
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7713; C09K11/7701; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
97 words
A method for making a cathodo-luminescent particle having a central region consisting of La 2 O 2 S with Tb 2 O 2 S uniformly distributed therethrough and a peripheral region of La 2 O 2 SO 4 with a distribution of Tb 2 O 2 SO 4 therethrough comprising: selecting a host material consisting of La 2 O 2 S particles with a uniform distribution of Tb 2 O 2 S therethrough, annealing said host material with oxygen for at least 25 minutes at a temperature in excess of 700° C, and air cooling said material.
Claim 2
Independent Claim
97 words
A method for making a cathodo-luminescent particle having a central region consisting of La 2 O 2 S with Tb 2 O 2 S uniformly distributed therethrough and a peripheral region of La 2 O 2 SO 4 with a distribution of Tb 2 O 2 SO 4 therethrough comprising: selecting a host material consisting of La 2 O 2 S particles with a uniform distribution of Tb 2 O 2 S therethrough, annealing said host material with oxygen for at least 25 minutes at a temperature in excess of 700° C, and air cooling said material.
Claim 3
Dependent Claim
43 words
The method as set forth in claim 1 wherein the step of annealing said host material further includes the step of rotating said host material in a rotating quartz chamber for producing a generally uniform thickness throughout the peripheral region of the particle.
Claim 4
Dependent Claim
35 words
The method as set forth in claim 2 further including the step of controlling the thickness of the peripheral region of said particle by limiting the amount of oxygen supplied during the step of annealing.
Claim 5
Dependent Claim
38 words
The method as set forth in claim 2 further including the step of controlling the thickness of the peripheral region of said particle by regulating the time duration of the step of annealing and the temperature utilized therein.
Claim 6
Independent Claim
120 words
A method for producing a cathodo-luminescent particle having a central region consisting of La 2 O 2 S with Tb 2 O 2 S uniformly distributed therethrough and a peripheral region of La 2 O 2 SO 4 with a distribution of Tb 2 O 2 SO 4 and Eu 2 O 2 SO 4 therethrough comprising: selecting a host material of La 2 O 2 S particles with a uniform distribution of Tb 2 O 2 S therethrough, combining said host material with an organic Eu compound, annealing the mixture of the organic Eu compound and the host material with oxygen for at least 25 minutes at a temperature in excess of 700° C, and air cooling said mixture.
Claim 7
Independent Claim
120 words
A method for producing a cathodo-luminescent particle having a central region consisting of La 2 O 2 S with Tb 2 O 2 S uniformly distributed therethrough and a peripheral region of La 2 O 2 SO 4 with a distribution of Tb 2 O 2 SO 4 and Eu 2 O 2 SO 4 therethrough comprising: selecting a host material of La 2 O 2 S particles with a uniform distribution of Tb 2 O 2 S therethrough, combining said host material with an organic Eu compound, annealing the mixture of the organic Eu compound and the host material with oxygen for at least 25 minutes at a temperature in excess of 700° C, and air cooling said mixture.
Claim 8
Dependent Claim
39 words
The method as set forth in claim 5 wherein the step of annealing further includes the step of rotating said mixture in a rotating quartz chamber for producing a generally uniform thickness throughout the peripheral region of said particle.
Claim 9
Dependent Claim
35 words
The method as set forth in claim 6 further including the step of controlling the thickness of the peripheral region of said particles by limiting the amount of oxygen supplied during the step of annealing.
Claim 10
Dependent Claim
33 words
The method of claim 6 further incuding the step of controlling the thickness of the peripheral region of said particle by regulating the duration of the step of annealing and temperature utilized therein.
Claim 11
Dependent Claim
23 words
The method as set forth in claim 5 wherein the organic compound of Eu is selected from the group comprising Eu-tris-2,2,6,6-tetramethylheptanedionate and Eu-pentanedione.
Claim 12
Independent Claim
173 words
The method of producing a penetration phosphor particle for use in an electron tube and having a central region of La 2 O 2 S with a substantially smaller concentration of Tb 2 O 2 S uniformly distributed therethrough and a pheripheral region surrounding said central region comprised on La 2 O 2 S with substantially smaller concentrations of Tb 2 O 2 S and Eu 2 O 2 S distributed therethrough comprising: selecting a host material of La 2 O 2 S particles having a uniform distribution of Tb 2 O 2 S therethrough, combining said host material with an organic Eu compound, annealing of the mixture of the host material and the organic Eu compound with oxygen for a period in excess of 20 minutes and at a temperature in excess of 700° C, firing the product from the preceding step in a furnace in an atmosphere comprising H 2 S and an inert gas bubbled through H 2 O, and cooling the product in an atmosphere of an inert gas.
Claim 13
Independent Claim
173 words
The method of producing a penetration phosphor particle for use in an electron tube and having a central region of La 2 O 2 S with a substantially smaller concentration of Tb 2 O 2 S uniformly distributed therethrough and a pheripheral region surrounding said central region comprised on La 2 O 2 S with substantially smaller concentrations of Tb 2 O 2 S and Eu 2 O 2 S distributed therethrough comprising: selecting a host material of La 2 O 2 S particles having a uniform distribution of Tb 2 O 2 S therethrough, combining said host material with an organic Eu compound, annealing of the mixture of the host material and the organic Eu compound with oxygen for a period in excess of 20 minutes and at a temperature in excess of 700° C, firing the product from the preceding step in a furnace in an atmosphere comprising H 2 S and an inert gas bubbled through H 2 O, and cooling the product in an atmosphere of an inert gas.
Claim 14
Dependent Claim
39 words
The method as set forth in claim 10 wherein the step of annealing further includes the step of rotating the mixture in a rotating quartz chamber for producing a generally uniform thickness throughout the peripheral region of the particle.
Claim 15
Dependent Claim
35 words
The method as set forth in claim 11 further including the step of controlling the thickness of the peripheral region of said particles by limiting the amount of oxygen supplied during the step of annealing.
Claim 16
Dependent Claim
32 words
The method of claim 11 further including the step of controlling the thickness of the peripheral region of said particles by regulating the duration of the annealing step and temperature utilized therein.
Claim 17
Dependent Claim
22 words
The method as described in claim 10 wherein the organic Eu compound is selected from the group comprising Eu-tris-2,2,6,6-tetramethylheptanedionate and Eu pentanedione.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |