Patent US4840747A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4840747A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for producing a terbium activated cerium magnesium aluminate phosphor

Assignee: Osram Sylvania Inc
•
Filing: 1988-11-23
•
Granted: 1989-06-20
•
Expires: 2008-11-23
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method is disclosed for producing a terbium activated cerium magnesium aluminate phosphor which comprises forming a uniform powder blend consisting essentially of in percent by weight from about 73 to about 74 aluminum oxide wherein the aluminum oxide can be alpha aluminum oxide or gamma aluminum oxide or combinations thereof, from about 12 to about 14 cerium oxide, from about 2 to about 3 magnesium, from about 0.3 to about 0.7 fluoride, and from about 6 to about 9 terbium, firing the blend in a non-oxidizing atmosphere at a temperature of from about 1500° C. to about 1800° C. for a sufficient time to produce the phosphor wherein the particle size is no greater than about 5 micrometers in diameter. The phosphor is then cooled and deagglomerated.

Inventors

  • 👤 Albert K. Fan
  • 👤 Douglas R. Ginter
  • 👤 Joseph J. Lenox
  • 👤 Thomas L. Henson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 14:58
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7774

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 161 words
A method for producing a terbium activated cerium magnesium aluminate phosphor, said method comprising: (a) forming a uniform powder blend consisting essentially of in percent by weight from about 73 to about 74 aluminum oxide, wherein said aluminum oxide is selected from the group consisting of alpha aluminum oxide, gamma aluminum oxide, and combinations thereof, from about 12 to about 14 cerium oxide, a source of magnesium in an amount of from about 2 to about 3 magnesium, a source of fluoride in an amount of from about 0.3 to about 0.7 fluoride, and a source of terbium in an amount of from about 6 to about 9 terbium; (b) firing said blend in a non-oxidizing atmosphere at a temperature of from about 1500° C. to about 1800° C. for a sufficient time to produce the phosphor wherein the particle size is no greater than about 5 micrometers in diameter; (c) cooling said phosphor; and (d) deaggmomerating the resulting cooled phosphor.
Claim 2
Independent Claim 161 words
A method for producing a terbium activated cerium magnesium aluminate phosphor, said method comprising: (a) forming a uniform powder blend consisting essentially of in percent by weight from about 73 to about 74 aluminum oxide, wherein said aluminum oxide is selected from the group consisting of alpha aluminum oxide, gamma aluminum oxide, and combinations thereof, from about 12 to about 14 cerium oxide, a source of magnesium in an amount of from about 2 to about 3 magnesium, a source of fluoride in an amount of from about 0.3 to about 0.7 fluoride, and a source of terbium in an amount of from about 6 to about 9 terbium; (b) firing said blend in a non-oxidizing atmosphere at a temperature of from about 1500° C. to about 1800° C. for a sufficient time to produce the phosphor wherein the particle size is no greater than about 5 micrometers in diameter; (c) cooling said phosphor; and (d) deaggmomerating the resulting cooled phosphor.

References Cited (Backward Citations)

DE226899C Cited
US4088922A Cited
US4150321A Cited
US4153572A Cited
US4631144A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-06-19 1992-12-19 1993-06-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-06-19 1996-12-19 1997-06-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-06-19 2000-12-19 2001-06-20 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag