US3899709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathode ray tube acoustic transducers
Assignee: EMI Ltd
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Filing: 1974-06-13
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Granted: 1975-08-12
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Expires: 1994-06-13
Abstract
Abstract An acoustic transducer comprises a cathode ray tube which has an acoustically transmissive faceplate and a layer of piezoelectric material, disposed internally of the tube supported by the faceplate. A layer of resilient material, which is acoustically transmissive and vacuum compatible is interposed between the layer of piezoelectric material and the faceplate to provide vibrational decoupling between them.
Inventors
- 👤 Patrick Harold Brown
- 👤 Raymond Frank Sivyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:17
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/495
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
119 words
A cathode ray tube acoustic transducer including, a. an evacuated envelope, b. a faceplate of acoustically transmissive material sealed to said envelope, c. a piezo-electric transducing layer supported by said faceplate within said envelope and sensitive to spatial variations of pressure applied thereto, d. an electron gun mounted within said envelope for providing a beam of electrons directed toward said transducing layer, e. means for scanning said beam, f. signal electrode means for deriving electrical output signals from said transducing layer indicative of the spatial variations of pressure applied thereto and g. an acoustically transmissive layer of resilient material separating and in contact with said faceplate and said transducing layer for maintaining the resonant frequency of said transducing layer.
Claim 2
Dependent Claim
119 words
A cathode ray tube acoustic transducer including, a. an evacuated envelope, b. a faceplate of acoustically transmissive material sealed to said envelope, c. a piezo-electric transducing layer supported by said faceplate within said envelope and sensitive to spatial variations of pressure applied thereto, d. an electron gun mounted within said envelope for providing a beam of electrons directed toward said transducing layer, e. means for scanning said beam, f. signal electrode means for deriving electrical output signals from said transducing layer indicative of the spatial variations of pressure applied thereto and g. an acoustically transmissive layer of resilient material separating and in contact with said faceplate and said transducing layer for maintaining the resonant frequency of said transducing layer.
Claim 3
Dependent Claim
31 words
An acoustic transducer according to claim 1 arranged such that part of said layer of resilient material may be compressed between said faceplate and said envelope to provide a hermetic seal.
Claim 4
Dependent Claim
16 words
An acoustic transducer according to claim 1 wherein said resilient layer is formed of Viton rubber.
Claim 5
Dependent Claim
14 words
An acoustic transducer according to claim 1 wherein said envelope is formed of glass.
Claim 6
Dependent Claim
14 words
An acoustic transducer according to claim 1 wherein said envelope is formed of metal.
Claim 7
Dependent Claim
17 words
An acoustic transducer according to claim 1 wherein said piezoelectric layer comprises a tesselation of smaller plates.
Claim 8
Dependent Claim
15 words
An acoustic transducer according to claim 1 wherein said faceplate is formed of Pyrex glass.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |