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
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.
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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 |