US5300862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Row activating method for fed cathodoluminescent display assembly
Assignee: Motorola Solutions Inc
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Filing: 1992-06-11
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Granted: 1994-04-05
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Expires: 2012-06-11
Abstract
Abstract A display addressing method applied in conjunction with an array of cold cathode field emission micro-emitters employs a row-by-row addressing technique in concert with controlled constant current sources connected simultaneously to each column of the array of emitters to provide a novel addressing scheme which yields an improvement in cathodoluminescent display brightness on the order of a full order of magnitude over that of the prior art.
Inventors
- 👤 Norman W. Parker
- 👤 James E. Jaskie
- 👤 Robert C. Kane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:21
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/22; H; H01; H01J; H01J31/00; H01J31/08; H01J31/10; H01J31/12; H01J31/123; H01J31/125; H01J31/127
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
338 words
A method for addressing an image display comprising the steps of: providing an image display device including a viewing screen whereon a cathodoluminescent material is disposed and an array of field emission devices distally disposed with respect to the viewing screen and further providing a plurality of conductive paths separated into a plurality of conductive paths in rows and a plurality of conductive paths in columns with each field emission device being selectively independently operably connected to one of the conductive paths separated into rows and one of the conductive paths separated into columns so that a plurality of the array of field emission devices is connected in each row and a plurality of the array of field emission devices is connected in each column; providing a plurality of controlled constant current sources each operably coupled between a conductive path of the plurality of conductive paths in columns and a reference potential; providing a switching circuit having an input terminal and a plurality of output terminals wherein each of the plurality of output terminals is operably connected to a different conductive path of the plurality of conductive paths in rows; providing a first voltage source operably coupled between the switching circuit input terminal and the reference potential and the switching circuit functions to operably connect the first voltage source to one selected conductive path of the plurality of conductive paths in rows at a given time; providing a second voltage source operably coupled between the viewing screen and the reference potential; and switching the switching circuit and controlling the constant current sources so that substantially all of the plurality of field emission devices connected in a selected conductive path of the plurality of conductive paths in rows are selectively simultaneously placed in an ON mode and each of the plurality of field emission devices connected in a selected conductive path of the plurality of conductive paths in rows emits an electron current substantially determined by a controlled constant current source of the plurality of controlled constant current sources.
Claim 2
Independent Claim
338 words
A method for addressing an image display comprising the steps of: providing an image display device including a viewing screen whereon a cathodoluminescent material is disposed and an array of field emission devices distally disposed with respect to the viewing screen and further providing a plurality of conductive paths separated into a plurality of conductive paths in rows and a plurality of conductive paths in columns with each field emission device being selectively independently operably connected to one of the conductive paths separated into rows and one of the conductive paths separated into columns so that a plurality of the array of field emission devices is connected in each row and a plurality of the array of field emission devices is connected in each column; providing a plurality of controlled constant current sources each operably coupled between a conductive path of the plurality of conductive paths in columns and a reference potential; providing a switching circuit having an input terminal and a plurality of output terminals wherein each of the plurality of output terminals is operably connected to a different conductive path of the plurality of conductive paths in rows; providing a first voltage source operably coupled between the switching circuit input terminal and the reference potential and the switching circuit functions to operably connect the first voltage source to one selected conductive path of the plurality of conductive paths in rows at a given time; providing a second voltage source operably coupled between the viewing screen and the reference potential; and switching the switching circuit and controlling the constant current sources so that substantially all of the plurality of field emission devices connected in a selected conductive path of the plurality of conductive paths in rows are selectively simultaneously placed in an ON mode and each of the plurality of field emission devices connected in a selected conductive path of the plurality of conductive paths in rows emits an electron current substantially determined by a controlled constant current source of the plurality of controlled constant current sources.
Claim 3
Dependent Claim
14 words
A method as claimed in claim 1 wherein the conductive path is electronically selected.
Claim 4
Dependent Claim
14 words
A method as claimed in claim 2 wherein electronic selection is sequential and cyclic.
Claim 5
Dependent Claim
34 words
A method as claimed in claim 3 wherein the cycle is determined to provide that each selected conductive path is operably connected to the first voltage source for approximately 20 micro-seconds during each cycle.
Claim 6
Dependent Claim
37 words
A method as claimed in claim 4 wherein the cycle provides that each conductive path operably coupled to the switching circuit is operably connected to the first voltage source on the order of 1 milli-second per second.
Claim 7
Dependent Claim
38 words
A method as claimed in claim 2 wherein the selected conductive path is operably coupled to an extraction electrode of field emission devices of the array of field emission devices which comprise a row of field emission devices.
Claim 8
Dependent Claim
48 words
A method as claimed in claim 6 wherein each field emission device of the row of field emission devices also operably coupled to the one controlled constant current source of the plurality of controlled constant current sources comprises a pixel electron source to energize a viewing screen pixel.
Claim 9
Dependent Claim
31 words
A method as claimed in claim 7 wherein each of the plurality of controlled constant current sources provides a determinate current of electrons corresponding to a desired viewing screen pixel brightness.
Claim 10
Dependent Claim
26 words
A method as claimed in claim 8 wherein a row of viewing screen pixels corresponding to a row of pixel electron sources are simultaneously selectively energized.
Claim 11
Dependent Claim
22 words
A method as claimed in claim 9 wherein sequentially energized rows of viewing screen pixels provides row by row image display addressing.
References Cited (Backward Citations)
US2553585A
Cited
US3889151A
Cited
US4459514A
Cited
US4723119A
Cited
US4835447A
Cited
US5153483A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-04-04 | 1997-10-04 | 1998-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-04 | 2001-10-04 | 2002-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-04 | 2005-10-04 | 2006-04-05 | $7700.00 | Window Closed / Lapsed |