US4689614A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Touch sensitive cathode ray tube
Assignee: Syrinx Innovations Ltd
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Filing: 1985-04-01
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Granted: 1987-08-25
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Expires: 2005-04-01
Abstract
Abstract A cathode ray tube provided on the exterior of its screen with a layer of polymeric piezoelectric material, for example polyvinylidene fluoride. Localized changes in physical stress on the layer, such as by way of localized pressure of heating on the layer, create a charge region which produces alteration of a beam current of an electron beam when the beam scans over the region. This alteration is detected, as by a sensing loop, to produce a data input.
Inventors
- 👤 John S. Strachan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:09
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/0414
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
81 words
A cathode ray tube comprising: a screen having an exterior surface; a transparent layer on said exterior surface, said layer being of polymeric piezoelectric material having the characteric of generating a localized charge at an area of said screen in response to localized changes in physical stress applied to said layer; detecting means for monitoring a beam current of an electron beam traveling along a beam path, to detect when said electron beam scans over a said area of localized charge.
Claim 2
Dependent Claim
81 words
A cathode ray tube comprising: a screen having an exterior surface; a transparent layer on said exterior surface, said layer being of polymeric piezoelectric material having the characteric of generating a localized charge at an area of said screen in response to localized changes in physical stress applied to said layer; detecting means for monitoring a beam current of an electron beam traveling along a beam path, to detect when said electron beam scans over a said area of localized charge.
Claim 3
Dependent Claim
16 words
A cathode ray tube according to claim 1, in which said layer is of polyvinylidene fluoride.
Claim 4
Dependent Claim
22 words
A cathode ray tube according to claim 1, in which said layer is coated with a transparent conductive layer connected to ground.
Claim 5
Dependent Claim
22 words
A cathode ray tube according to claim 2, in which said layer is coated with a transparent conductive layer connected to ground.
Claim 6
Dependent Claim
28 words
A cathode ray tube according to claims 1, 2, 3, or 4, in which said detecting means comprises a current sensing loop disposed around said electron beam path.
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) | 1990-08-24 | 1991-02-23 | 1991-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-24 | 1995-02-23 | 1995-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-24 | 1999-02-23 | 1999-08-25 | $7700.00 | Window Closed / Lapsed |