US4281407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface acoustic wave pickup and recording device
Assignee: RCA Corp
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Filing: 1979-12-14
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Granted: 1981-07-28
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Expires: 1999-12-14
Abstract
Abstract A surface acoustic wave (SAW) pickup and record stylus is constructed from an elongated substrate which supports the propagation of SAW. The substrate is tapered to a tip at one end and a fan-shaped interdigital electrode structure having curved fingers is formed thereon. During operation in the pickup mode a beam of SAW is focused to the tip of the stylus which is arranged in contact with a record medium. During playback, the beam reflected by the record medium generates a signal in the interdigital electrode of the stylus representative of the acoustic conditions at the stylus tip and, correspondingly, of the information recorded on the record medium surface. In the record mode the stylus is brought into contact with a record medium. During recording, the input power applied to the interdigital electrode is increased to effect a deformation of the surface of the record medium representative of the information to be recorded.
Inventors
- 👤 Soitiro Tosima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:23
CPC Classifications
G; G11; G11B; G11B9/00; G10; G10K; G10K11/00; G10K11/36; G11B11/00; G11B11/16
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
77 words
In a disc record or playback system for recording or retrieving information in the form of surface variations in a disc-shaped record medium, a surface acoustic wave stylus, comprising: an elongated member tapered to a tip at one end, said member being arranged to support the propagation of surface acoustic wave in at least one region of said member; and electrode means provided in the vicinity of said tip for focusing surface acoustic waves to said tip.
Claim 2
Dependent Claim
77 words
In a disc record or playback system for recording or retrieving information in the form of surface variations in a disc-shaped record medium, a surface acoustic wave stylus, comprising: an elongated member tapered to a tip at one end, said member being arranged to support the propagation of surface acoustic wave in at least one region of said member; and electrode means provided in the vicinity of said tip for focusing surface acoustic waves to said tip.
Claim 3
Dependent Claim
19 words
The surface acoustic wave stylus according to claim 1 wherein said focussing electrode means comprises a fan-shaped interdigital electrode.
Claim 4
Dependent Claim
17 words
The surface acoustic wave stylus according to claim 2 wherein said fan-shaped interdigital electrode comprises curved fingers.
Claim 5
Dependent Claim
42 words
The surface acoustic wave stylus according to claim 3 wherein said fan-shaped electrode is positioned on said member such that the narrowest section of said fan-shaped electrode is in the vicinity of the narrowest portion of said tapered end of said member.
Claim 6
Dependent Claim
18 words
The surface acoustic wave stylus according to claim 4 wherein said member is formed from a piezoelectric material.
Claim 7
Dependent Claim
19 words
The surface acoustic wave stylus according to claim 4 further comprising: a piezoelectric film overlying said fan-shaped interdigital electrode.
Claim 8
Dependent Claim
176 words
A surface acoustic wave device, comprising: an elongated member tapered to a tip at one end, said member being arranged to support the propagation of surface acoustic waves in at least one region of said member; electrode means provided in the vicinity of said tip for focusing surface acoustic waves to said tip, said electrode means comprising a fan-shaped interdigital electrode having curved fingers; said fan-shaped electrode being positioned on said member such that the narrowest section of said fan-shaped electrode is in the vicinity of the narrowest portion of said tapered end of said member; means, coupled to said interdigital electrode, for generating surface acoustic waves on the surface of said member in said at least one region; and means, coupled to said interdigital electrode, for detecting impedance variations of said interdigital electrode; whereby said surface acoustic wave device is used to recover information signals recorded on a surface of a record medium and whereby the impedance variations detected by said interdigital electrode are representative of the information signals recorded on said record medium surface.
Claim 9
Dependent Claim
176 words
A surface acoustic wave device, comprising: an elongated member tapered to a tip at one end, said member being arranged to support the propagation of surface acoustic waves in at least one region of said member; electrode means provided in the vicinity of said tip for focusing surface acoustic waves to said tip, said electrode means comprising a fan-shaped interdigital electrode having curved fingers; said fan-shaped electrode being positioned on said member such that the narrowest section of said fan-shaped electrode is in the vicinity of the narrowest portion of said tapered end of said member; means, coupled to said interdigital electrode, for generating surface acoustic waves on the surface of said member in said at least one region; and means, coupled to said interdigital electrode, for detecting impedance variations of said interdigital electrode; whereby said surface acoustic wave device is used to recover information signals recorded on a surface of a record medium and whereby the impedance variations detected by said interdigital electrode are representative of the information signals recorded on said record medium surface.
Claim 10
Dependent Claim
124 words
A surface acoustic wave device, comprising: an elongated member tapered to a tip at one end, said member being arranged to support the propagation of surface acoustic waves in at least one region of said member; electrode means provided in the vicinity of said tip for focusing surface acoustic waves to said tip, said electrode means comprising a fan-shaped interdigital electrode having curved fingers; said fan-shaped electrode being positioned on said member such that the narrowest section of said fan-shaped electrode is in the vicinity of the narrowest portion of said tapered end of said member; said member having a shank end opposite said tapered end; and a reflecting interdigital electrode interposed between said fan-shaped interdigital electrode and said shank end of said member.
Claim 11
Dependent Claim
124 words
A surface acoustic wave device, comprising: an elongated member tapered to a tip at one end, said member being arranged to support the propagation of surface acoustic waves in at least one region of said member; electrode means provided in the vicinity of said tip for focusing surface acoustic waves to said tip, said electrode means comprising a fan-shaped interdigital electrode having curved fingers; said fan-shaped electrode being positioned on said member such that the narrowest section of said fan-shaped electrode is in the vicinity of the narrowest portion of said tapered end of said member; said member having a shank end opposite said tapered end; and a reflecting interdigital electrode interposed between said fan-shaped interdigital electrode and said shank end of said member.
Claim 12
Dependent Claim
98 words
In a recording system for recording information signals on a record medium, the apparatus comprising: a surface acoustic wave stylus having a tapered tip on one end thereof, said tapered tip having a fan-shaped interdigital electrode structure formed thereon; said surface acoustic wave device being supported such that said tapered tip contacts said record medium; means for establishing relative motion between said tapered tip and said record medium; and means for coupling said information signals to be recorded to said interdigital electrode structure whereby said tapered tip effects variations in said record medium corresponding to said information signals.
Claim 13
Dependent Claim
98 words
In a recording system for recording information signals on a record medium, the apparatus comprising: a surface acoustic wave stylus having a tapered tip on one end thereof, said tapered tip having a fan-shaped interdigital electrode structure formed thereon; said surface acoustic wave device being supported such that said tapered tip contacts said record medium; means for establishing relative motion between said tapered tip and said record medium; and means for coupling said information signals to be recorded to said interdigital electrode structure whereby said tapered tip effects variations in said record medium corresponding to said information signals.
Claim 14
Dependent Claim
100 words
In a playback system for recovering information signals recorded in the form of variations in a record medium, the apparatus comprising: a surface acoustic wave stylus having a tapered tip on one end thereof, said tapered tip having a fan-shaped interdigital electrode structure formed thereon; said surface acoustic wave device being supported such that said tapered tip contacts said record medium; means for establishing relative motion between said tapered tip and said record medium; and means, coupled to said interdigital electrode structure, for sensing signals which vary in accordance with variations on said record medium corresponding to said information signals.
Claim 15
Dependent Claim
100 words
In a playback system for recovering information signals recorded in the form of variations in a record medium, the apparatus comprising: a surface acoustic wave stylus having a tapered tip on one end thereof, said tapered tip having a fan-shaped interdigital electrode structure formed thereon; said surface acoustic wave device being supported such that said tapered tip contacts said record medium; means for establishing relative motion between said tapered tip and said record medium; and means, coupled to said interdigital electrode structure, for sensing signals which vary in accordance with variations on said record medium corresponding to said information signals.
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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) | 1984-07-27 | 1985-01-26 | 1985-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-27 | 1989-01-26 | 1989-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-27 | 1993-01-26 | 1993-07-28 | $7700.00 | Window Closed / Lapsed |