Patent EP0573754A1 successfully refreshed from Google Patents.
EP0573754A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Addressing method for cathodoluminescent display assembly
Assignee: Motorola Solutions Inc
•
Filing: 1993-04-05
•
Granted: —
•
Expires: 2013-04-05
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 (301A - 301D) 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
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:27
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: 10
Claim 1
Independent Claim
169 words
A method for addressing an image display including providing an image display device (300) including a viewing screen (305) whereon a cathodoluminescent material (108) is disposed and an array of field emission devices distally disposed with respect to the viewing screen and selectively independently operably connected each to at least some of a plurality of conductive paths (304A, 304B) and characterized by the steps of: providing a plurality of controlled constant current sources (301A -301D) each operably coupled between a conductive path of the plurality of conductive paths and a reference potential; providing a switching circuit (302) having an input terminal (311) and a plurality of output terminals (316) wherein each of at least some of the plurality of output terminals is operably connected to one conductive path of the plurality of conductive paths; providing a first voltage source (303) operably coupled between the switching circuit input terminal and the reference potential; and providing a second voltage source (310) operably coupled between the viewing screen and the reference potential.
Claim 2
Dependent Claim
40 words
A method as claimed in claim 1 further characterized in that the switching circuit (302) functions to operably connect the first voltage source (303) to one conductive path of the plurality of conductive paths (304A, 304B) at a given time.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 2 further characterized in that the conductive path is electronically selected.
Claim 4
Dependent Claim
17 words
A method as claimed in claim 3 further characterized in that electronic selection is sequential and cyclic.
Claim 5
Dependent Claim
37 words
A method as claimed in claim 4 further characterized in that 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
40 words
A method as claimed in claim 5 further characterized in that 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
42 words
A method as claimed in claim 3 further characterized in that the selected conductive path is operably coupled to an extraction electrode (304B0 of field emission devices of the array of field emission devices which comprise a row of field emission devices.
Claim 8
Dependent Claim
66 words
A method as claimed in claim 7 further characterized in that substantially all of the field emission devices of a row of field emission devices are selectively simultaneously placed in an ON mode and wherein each field emission device of the row of field emission devices emits an electron current substantially determined by a controlled constant current source of the plurality of controlled constant current sources.
Claim 9
Dependent Claim
54 words
A method as claimed in claim 7 further characterized in that 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 (301A - 301D) comprises a pixel electron source to energize a viewing screen pixel.
Claim 10
Dependent Claim
157 words
An image display assembly characterized by: an image display device (300) including a viewing screen (305) whereon a cathodoluminescent material (108) is disposed and an array of field emission devices distally disposed with respect to the viewing screen and selectively independently operably connected each to at least some of a plurality of conductive paths (304A, 304B); a plurality of controlled constant current sources (301A - 301D) each operably coupled between a conductive path of the plurality of conductive paths and a reference potential; a switching circuit (302) having an input terminal (311) and a plurality of output terminals (316) wherein each of at least some of the plurality of output terminals is operably connected to one conductive path of the plurality of conductive paths; a first voltage source (303) operably coupled between the switching circuit input terminal and the reference potential; and a second voltage source (310) operably coupled between the viewing screen and the reference potential.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.