US4499005A
Expired / Lapsed
US
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Infrared emitting phosphor
Assignee: Osram Sylvania Inc
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Filing: 1984-04-30
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Granted: 1985-02-12
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Expires: 2004-04-30
Abstract
Abstract A ZnS:Tm,Ag cathodoluminescent phosphor composition is described. The phosphor emits in the infrared region at approximately 800 nm. The method of making this phosphor is also described. The ingredients are mixed, formed into a cake, dried, comminuted, heated at 800° C. followed by a 1180° C. firing and then cooled to room temperature. All the heating and cooling is done in a hydrogen sulfide atmosphere.
Inventors
- 👤 James R. McColl
- 👤 Thomas E. Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:16
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7701; C09K11/7702
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
41 words
A luminescent composition comprising thulium and silver coactivated zinc sulfide having the approximate formula ZnS:Tm.sub.x Ag.sub.y wherein x is from about 100 to about 1000 atomic parts per million, y is from about 10 to about 100 atomic parts per million.
Claim 2
Dependent Claim
41 words
A luminescent composition comprising thulium and silver coactivated zinc sulfide having the approximate formula ZnS:Tm.sub.x Ag.sub.y wherein x is from about 100 to about 1000 atomic parts per million, y is from about 10 to about 100 atomic parts per million.
Claim 3
Independent Claim
147 words
A method for making a thulium and silver coactivated zinc sulfide phosphor comprising the steps Step 1. mixing zinc sulfide powder with about 100 to about 1000 atomic parts per million thulium and about 10 to about 100 atomic parts per million silver in water to form a slurry; Step 2. removing said water from said slurry of step 1 by evaporation to form a dry cake; Step 3. comminuting said dry cake from step 2 to form a powder; Step 4. heating said powder from step 3 at a temperature of about 800° C. for about 30 minutes in a hydrogen sulfide atmosphere; Step 5. increasing said temperature of about 800° C. from step 4 to about 1180° C. for about 30 minutes to form a reacted powder; and Step 6. cooling said reacted powder from step 5 to room temperature in a hydrogen sulfide atmosphere.
Claim 4
Independent Claim
147 words
A method for making a thulium and silver coactivated zinc sulfide phosphor comprising the steps Step 1. mixing zinc sulfide powder with about 100 to about 1000 atomic parts per million thulium and about 10 to about 100 atomic parts per million silver in water to form a slurry; Step 2. removing said water from said slurry of step 1 by evaporation to form a dry cake; Step 3. comminuting said dry cake from step 2 to form a powder; Step 4. heating said powder from step 3 at a temperature of about 800° C. for about 30 minutes in a hydrogen sulfide atmosphere; Step 5. increasing said temperature of about 800° C. from step 4 to about 1180° C. for about 30 minutes to form a reacted powder; and Step 6. cooling said reacted powder from step 5 to room temperature in a hydrogen sulfide atmosphere.
Claim 5
Dependent Claim
18 words
A infrared emitting phosphor comprising a thulium and silver coactivated zinc sulfide phosphor emitting at about 800 nm.
Claim 6
Dependent Claim
18 words
A infrared emitting phosphor comprising a thulium and silver coactivated zinc sulfide phosphor emitting at about 800 nm.
References Cited (Backward Citations)
US381709A
Cited
US3203899A
Cited
US2774901A
Cited
US3459667A
Cited
US3785991A
Cited
USB381709I5
Cited
US4208612A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |