US3876906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual display devices
Assignee: Ferranti International PLC
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Filing: 1973-06-19
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Granted: 1975-04-08
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Expires: 1993-06-19
Abstract
Abstract A visual display device consists of a matrix of cold-cathode direct-current discharge devices any one of which is addressable by a cross-bar arrangement of conductors to produce a required display. Each discharge device is provided with a subsidiary electrode, say an anode, spaced further than the main anode electrode from the cathode electrode. The subsidiary electrodes are capacitively coupled to conductors grouped as for the main anodes. The arrangements permit discharge devices which contained a discharge and which have been turned off to be turned on a short time later by way of a pulse applied to the subsidiary anodes but not those devices which did not contain a discharge. By varying the time delay between turn-off and turn-on, variable brightness can be obtained.
Inventors
- 👤 Frank Walters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:33
CPC Classifications
H; H01; H01J; H01J17/00; H01J17/38; H01J17/48; H01J17/49; H01J17/492
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
282 words
A visual display device incorporating a two-co-ordinate array of gas-filled cold-cathode direct-current discharge devices adapted to enable a variable brightness display to be produced and producing the variation without applying to any conductor of the panel a potential in excess of a maintaining potential comprising a block of electrically insulating material containing a plurality of gas-filled apertures arranged in a two-co-ordinate array; a first end plate of electrically insulating material fixed to the block and sealing one end of the apertures, a plurality of first electrodes, one for each discharge device, carried by a face of the first end plate adjacent one end of the aperture, a plurality of electrical impedance elements, carried by said face of the first end plate, individual elements being connected to individual first electrodes, a first set of electrical conductors also carried by said face of the first endplate, individual conductors interconnecting the impedance elements associated with particular values of one co-ordinate of the array; a second set of electrical conductors adjacent the other end of the apertures, individual conductors of the second set forming second electrodes of the discharge devices associated with particular values of the other co-ordinate of the array; a second end-plate of electrically insulating material fixed to the block and sealing the other ends of the apertures and adapted to retain the second set of electrical conductors, a third set of electrical conductors carried by the second end plate, means for capacitively coupling individual conductors of the third set to the discharge devices associated with particular values of said other co-ordinate of the array and said individual conductors of the third set being more remote than the second electrodes from the first electrodes.
Claim 2
Dependent Claim
282 words
A visual display device incorporating a two-co-ordinate array of gas-filled cold-cathode direct-current discharge devices adapted to enable a variable brightness display to be produced and producing the variation without applying to any conductor of the panel a potential in excess of a maintaining potential comprising a block of electrically insulating material containing a plurality of gas-filled apertures arranged in a two-co-ordinate array; a first end plate of electrically insulating material fixed to the block and sealing one end of the apertures, a plurality of first electrodes, one for each discharge device, carried by a face of the first end plate adjacent one end of the aperture, a plurality of electrical impedance elements, carried by said face of the first end plate, individual elements being connected to individual first electrodes, a first set of electrical conductors also carried by said face of the first endplate, individual conductors interconnecting the impedance elements associated with particular values of one co-ordinate of the array; a second set of electrical conductors adjacent the other end of the apertures, individual conductors of the second set forming second electrodes of the discharge devices associated with particular values of the other co-ordinate of the array; a second end-plate of electrically insulating material fixed to the block and sealing the other ends of the apertures and adapted to retain the second set of electrical conductors, a third set of electrical conductors carried by the second end plate, means for capacitively coupling individual conductors of the third set to the discharge devices associated with particular values of said other co-ordinate of the array and said individual conductors of the third set being more remote than the second electrodes from the first electrodes.
Claim 3
Dependent Claim
25 words
A visual display device as claimed in claim 1 in which the conductors of the second set extend across the end faces of the apertures.
Claim 4
Dependent Claim
30 words
A visual display device as claimed in claim 1 in which the conductors of the third set are carried by a face of the second end plate adjacent the block.
Claim 5
Dependent Claim
29 words
A visual display device as claimed in claim 1 in which the conductors of the third set extend in a direction parallel to the conductors of the second set.
Claim 6
Dependent Claim
49 words
A visual display device as claimed in claim 4 in which the means for capacitively coupling the conductors of the third set and the discharge devices comprises a layer of dielectric material carried by a face of the second end plate and covering the third set of electrical conductors.
Claim 7
Dependent Claim
49 words
A visual display device as claimed in claim 1 in which the means for capacitively coupling the conductors of the third set and the discharge devices comprises a layer of dielectric material carried by a face of the second end plate and covering the third set of electrical conductors.
Claim 8
Dependent Claim
47 words
A visual display device as claimed in claim 6 in which the portions of said layer of dielectric material which are adjacent to and which cover the third set of conductors and in registration with the apertures are of less thickness than the remainder of said layer.
Claim 9
Dependent Claim
17 words
A visual display device as claimed in claim 6 in which the dielectric material is solder glass.
Claim 10
Dependent Claim
200 words
A visual display device incorporating a two-co-ordinate array of gas-filled cold-cathode direct-current discharge devices, adapted to enable a variable brightness display to be produced and producing the variation without applying to any conductor of the panel a potential in excess of a maintaining potential, each discharge device of the array having a gas filled discharge space, a first electrode communicating with the discharge space, an impedance element connected to the first electrode, a second electrode in communication with the discharge space, a third electrode more remote than the second electrode from the first electrode, means for capacitively coupling the third electrode to the discharge device, the array also comprising a first set of electrical conductors, individual conductors of the set interconnecting the impedance elements of the discharge devices associated with the individual values of one co-ordinate of the array, a second set of electrical conductors, individual conductors of the set interconnecting the second electrodes of the discharge devices associated with individual values of the other co-ordinate of the array, and a third set of conductors, individual conductors of the third set interconnecting the third electrodes of the discharge devices associated with individual values of said other co-ordinate of the array.
Claim 11
Dependent Claim
200 words
A visual display device incorporating a two-co-ordinate array of gas-filled cold-cathode direct-current discharge devices, adapted to enable a variable brightness display to be produced and producing the variation without applying to any conductor of the panel a potential in excess of a maintaining potential, each discharge device of the array having a gas filled discharge space, a first electrode communicating with the discharge space, an impedance element connected to the first electrode, a second electrode in communication with the discharge space, a third electrode more remote than the second electrode from the first electrode, means for capacitively coupling the third electrode to the discharge device, the array also comprising a first set of electrical conductors, individual conductors of the set interconnecting the impedance elements of the discharge devices associated with the individual values of one co-ordinate of the array, a second set of electrical conductors, individual conductors of the set interconnecting the second electrodes of the discharge devices associated with individual values of the other co-ordinate of the array, and a third set of conductors, individual conductors of the third set interconnecting the third electrodes of the discharge devices associated with individual values of said other co-ordinate of the array.
Claim 12
Dependent Claim
57 words
A visual display device as set forth in claim 9 in which the means for capacitively coupling the third electrode and the discharge space comprises a layer of dielectric material between the discharge spaces of the array and the third electrode of the array having areas of reduced thickness in registration with the gas filled discharge spaces.
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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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |