US4889974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin-film heating element
Assignee: US Philips Corp
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Filing: 1988-02-22
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Granted: 1989-12-26
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Expires: 2008-02-22
Abstract
Abstract A thin-film heating element is formed of a temperature-stable, electrically insulating substrate having a thin, electrically conductive metal oxide film which is doped with foreign atoms which compensate each other in pairs and which each consist of at least one acceptor-forming element and one donor-forming element the metal oxide film being provided with connecting electrodes; the metal oxide film being doped with maximally 10% of each of the foreign atoms compensating each other in pairs, the quantity of the atoms differing maximally 10%.
Inventors
- 👤 Hans Auding
- 👤 Gunter Frank
- 👤 Heiner Kostlin
- 👤 Bruno Vitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:50
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H01; H01C; H01C17/00; H01C17/06; H01C17/20; H01C7/00; H01C7/02; H01C7/021; H05B3/20; H05B3/22; H05B3/26; H05B3/265
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
94 words
A thin-film heating element comprising a temperature-stable, electrically insulating substrate having a thin, electrically conductive metal oxide film which is doped with foreign atoms which compensate each other in pairs and each of which pairs consist of at least one acceptor-forming element and one donor-forming element, the metal oxide film being provided with connecting electrodes, characterized in that the metal oxide film is doped with maximally 10 at % of each of the foreign atoms compensating each other in pairs, the quantity of said acceptor-forming elements and said donor-forming elements differs maximally by 10%.
Claim 2
Dependent Claim
94 words
A thin-film heating element comprising a temperature-stable, electrically insulating substrate having a thin, electrically conductive metal oxide film which is doped with foreign atoms which compensate each other in pairs and each of which pairs consist of at least one acceptor-forming element and one donor-forming element, the metal oxide film being provided with connecting electrodes, characterized in that the metal oxide film is doped with maximally 10 at % of each of the foreign atoms compensating each other in pairs, the quantity of said acceptor-forming elements and said donor-forming elements differs maximally by 10%.
Claim 3
Dependent Claim
20 words
A heating element as claimed in claim 1, characterized in that the metal oxide film is a SnO 2 -film.
Claim 4
Dependent Claim
25 words
A heating element as claimed in claim 2, characterized in that the metal oxide film is doped with indium, boron and/or aluminum as acceptor-forming element(s).
Claim 5
Dependent Claim
24 words
A heating element as claimed in claim 2, characterized in that the metal oxide film is doped with antimony and/or fluorine as donor-forming element(s).
Claim 6
Dependent Claim
23 words
A heating element as claimed in claim 2, characterized in that the metal oxide film is doped with zinc as an acceptor-forming element.
Claim 7
Dependent Claim
38 words
A heating element as claimed in claim 1, characterized in that the metal oxide film is doped with at least one acceptor-forming element and at least one donor-forming element, in a quantity from 3 to 5 at. %.
Claim 8
Dependent Claim
30 words
A heating element as claimed in claim 1, characterized in that the metal oxide film is produced by pyrolysis of a solution containing the elements used to produce the layer.
Claim 9
Dependent Claim
17 words
A heating element as claimed in claim 1, characterized in that the substrate consists of hard glass.
Claim 10
Dependent Claim
17 words
A heating element as claimed in claim 1, characterized in that the substrate consists of quartz glass.
Claim 11
Dependent Claim
17 words
A heating element as claimed in claim 1, characterized in that the substrate consists of a ceramic.
References Cited (Backward Citations)
US3551195A
Cited
US4340508A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |