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US4931312A Expired / Lapsed US ⏱️ 0.0 years remaining

Sol-gel process for producing liminescent thin film, and film so produced and devices utilizing same

Assignee: Philips North America LLC
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Filing: 1988-10-20
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Granted: 1990-06-05
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Expires: 2008-10-20
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Abstract

Abstract Luminescent thin films are produced by a sol-gel process in which a gellable liquid is applied to a substrate to form a thin film, gelled and heated to remove volatile constituents and form a polycrystalline luminescent material.

Inventors

  • 👤 Dagobert M. de Leeuw
  • 👤 Walter K. Zwicker
  • 👤 Rameshwar N. Bhargava

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 10:38
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; H; H01; H01J; H01J9/00; H01J9/20; H01J9/22; H01J9/221; H01J9/223

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 143 words
A sol-gel process for producing a thin film of luminescent material on a substrate, the process comprising: (a) forming a gellable liquid by first dissolving at least one metal alkoxide precursor of at least one constituent of the luminescent material in a water-miscible non-polar solvent, and adding sufficient water to at least partially hydrolize the alkoxide without gelling the solution; (b) applying the gellable liquid to a substrate to form a thin film; (c) gelling the film by allowing the film to air dry; and (d) heating the gelled film to decompose precursors into non-volatile constituents and volatile components, to remove the volatile components, and to convert the non-volatile, non-luminescent constituents into a luminescent material, the heating being carried out in an atmosphere containing a gaseous reactant in order to promote incorporation of the reactant which is ion forming into the luminescent material.
Claim 2
Dependent Claim 143 words
A sol-gel process for producing a thin film of luminescent material on a substrate, the process comprising: (a) forming a gellable liquid by first dissolving at least one metal alkoxide precursor of at least one constituent of the luminescent material in a water-miscible non-polar solvent, and adding sufficient water to at least partially hydrolize the alkoxide without gelling the solution; (b) applying the gellable liquid to a substrate to form a thin film; (c) gelling the film by allowing the film to air dry; and (d) heating the gelled film to decompose precursors into non-volatile constituents and volatile components, to remove the volatile components, and to convert the non-volatile, non-luminescent constituents into a luminescent material, the heating being carried out in an atmosphere containing a gaseous reactant in order to promote incorporation of the reactant which is ion forming into the luminescent material.
Claim 3
Dependent Claim 138 words
A sol-gel process for producing a thin film of luminescent material on a substrate, the process comprising: (a) forming a gellable liquid by suspending in the liquid a co-precipitate of at least two metal hydroxide prescursors of at least two constituents of the luminescent material in the proportion required to form the luminescent material; (b) applying the gellable liquid to a substrate to form a thin film; (c) gelling the film by allowing the film to air dry; and (d) heating the gelled film to decompose the precursors into non-volatile constituents and volatile components, to remove the volatile components, and to convert the non-volatile, non-luminescent constituents into a luminescent material, the heating being carried out in an atmosphere containing a gaseous reactant which is ion forming in order to promote incorporation of the reactant into the luminescent material.
Claim 4
Dependent Claim 138 words
A sol-gel process for producing a thin film of luminescent material on a substrate, the process comprising: (a) forming a gellable liquid by suspending in the liquid a co-precipitate of at least two metal hydroxide prescursors of at least two constituents of the luminescent material in the proportion required to form the luminescent material; (b) applying the gellable liquid to a substrate to form a thin film; (c) gelling the film by allowing the film to air dry; and (d) heating the gelled film to decompose the precursors into non-volatile constituents and volatile components, to remove the volatile components, and to convert the non-volatile, non-luminescent constituents into a luminescent material, the heating being carried out in an atmosphere containing a gaseous reactant which is ion forming in order to promote incorporation of the reactant into the luminescent material.

References Cited (Backward Citations)

US3927224A Cited
US4271210A Cited
US4278632A Cited
US4419115A Cited
US4420517A Cited
US4472510A Cited
JPS59138291A Cited
US4551397A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-04 1993-12-04 1994-06-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-06-04 1997-12-04 1998-06-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-06-04 2001-12-04 2002-06-05 $7700.00 Window Closed / Lapsed

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