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US4245200A
Expired / Lapsed
US
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Method of intermediate frequency filtration in a television receiver
Assignee: Toshiba Corp
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Filing: 1978-11-22
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Granted: 1981-01-13
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Expires: 1998-11-22
Abstract
Abstract An elastic surface wave device includes a transducer having an elastic surface wave propagated in the direction of 75 to 133 degrees to a Y-axis on an X-cut lithium tantalate (LiTaO 3 ) substrate.
Inventors
- 👤 Sadao Takahashi
- 👤 Hitoshi Hirano
- 👤 Sadao Matsumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:15
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/36; H; H03; H03H; H03H3/00; H03H3/007; H03H3/08; H03H3/10; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02559
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
154 words
A method of intermediate frequency filtration in a television receiver comprising: applying a television intermediate frequency signal to an elastic surface wave device, which elastic surface wave device includes at least one transducer which includes an X-cut lithium tantalate (LiTaO 3 ) substrate in which the lithium tantalate crystal is vertically x-cut at an angle of ±10° from the substrate based on the IRE standard and the Y-axis based on the IRE standard in an axis projected on the X-cut substrate, said intermediate frequency signal being applied in a direction to produce an elastic surface wave propagated in a direction of (112°±10°) or (112°+180°±10°) to the Y-axis on the X-cut lithium tantalate substrate, said intermediate frequency signal being applied to electrodes on said substrate which are oriented on said substrate to produce said elastic surface wave; and dimensioning said transducer such that the passband width of the filter is less than about 5 MHz.
Claim 2
Independent Claim
154 words
A method of intermediate frequency filtration in a television receiver comprising: applying a television intermediate frequency signal to an elastic surface wave device, which elastic surface wave device includes at least one transducer which includes an X-cut lithium tantalate (LiTaO 3 ) substrate in which the lithium tantalate crystal is vertically x-cut at an angle of ±10° from the substrate based on the IRE standard and the Y-axis based on the IRE standard in an axis projected on the X-cut substrate, said intermediate frequency signal being applied in a direction to produce an elastic surface wave propagated in a direction of (112°±10°) or (112°+180°±10°) to the Y-axis on the X-cut lithium tantalate substrate, said intermediate frequency signal being applied to electrodes on said substrate which are oriented on said substrate to produce said elastic surface wave; and dimensioning said transducer such that the passband width of the filter is less than about 5 MHz.
Claim 3
Dependent Claim
41 words
The method of intermediate frequency filtration according to claim 1 comprising applying said intermediate frequency signal in a direction to produce an elastic surface wave propagated in a direction of about 112.2° to the Y-axis of said X-cut lithium tantalate substrate.
Claim 4
Dependent Claim
46 words
The method of intermediate frequency filtration according to claim 1 comprising applying said intermediate frequency signal in a direction to produce an elastic surface wave propagated in a direction within a range of from 110.2° to 112.2° to the Y-axis of said X-cut lithium tantalate substrate.
Claim 5
Dependent Claim
41 words
The method of intermediate frequency filtration according to claim 1 comprising applying said intermediate frequency signal in a direction to produce an elastic surface wave propagated in a direction of about 292.2° to the Y-axis of said X-cut lithium tantalate substrate.
Claim 6
Dependent Claim
37 words
The method of intermediate frequency filtration according to claim 1 comprising applying said intermediate frequency signal in a direction to produce an elastic surface wave propagated in a direction within a range of from 290.2° to 292.2°.
Claim 7
Dependent Claim
18 words
The method of intermediate frequency filtration according to claim 1 comprising aligning said electrodes in said propagation direction.
Claim 8
Dependent Claim
21 words
The method of intermediate frequency filtration according to claim 6 wherein said electrodes comprise interdigital electrodes aligned in said propagation direction.
Claim 9
Dependent Claim
34 words
The method of intermediate frequency filtration according to claim 7 wherein said interdigital electrodes comprise a plurality of elongate digit electrodes, and comprising orienting said elongate digit electrodes substantially perpendicularly to said propagation direction.
References Cited (Backward Citations)
US3818382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |