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US5574333A
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US
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Method for manufacturing a cathode for fluorescent display screens of the microtip-type
Assignee: Pixel International SA
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Filing: 1995-02-17
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Granted: 1996-11-12
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Expires: 2015-02-17
Abstract
Abstract A method for manufacturing a fluorescent display screen cathode including microtips, comprises a supporting plate bearing cathode conductors in meshed columns, a resistive layer bearing microtips, an insulating layer and a grid conductive layer in rows. The method comprises the step of simultaneously etching the three upper grid layer, insulating layer and resistive layer according to a single perforated pattern defining both the grid rows and the access resistance to the microtips through the resistive layer.
Inventors
- 👤 Jean-Frederic Clerc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:22
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/022; H01J9/025; H01J31/00; H01J31/08; H01J31/10; H01J31/12; H01J31/123; H01J31/125; H01J31/127; H01J2201/00; H01J2201/30; H01J2201/319
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
93 words
A microtip fluorescent display screen having a cathode plate (1) including a supporting plate (1) bearing cathode conductors in meshed columns (2), a resistive layer (3) bearing microtips (4), an insulating layer (5) and a grid conductive layer (6) disposed in rows, wherein the grid layer (6), insulating layer (5) and resistive layer (3) are etched according to a single pattern forming predetermined elements so that empty areas (9) remain between said elements and the column meshes, thus allowing the observation of the phosphor elements of an anode plate through the cathode structure.
Claim 2
Dependent Claim
93 words
A microtip fluorescent display screen having a cathode plate (1) including a supporting plate (1) bearing cathode conductors in meshed columns (2), a resistive layer (3) bearing microtips (4), an insulating layer (5) and a grid conductive layer (6) disposed in rows, wherein the grid layer (6), insulating layer (5) and resistive layer (3) are etched according to a single pattern forming predetermined elements so that empty areas (9) remain between said elements and the column meshes, thus allowing the observation of the phosphor elements of an anode plate through the cathode structure.
Claim 3
Dependent Claim
74 words
The microtip fluorescent display screen of claim 1, wherein the elements constituting the pattern of the grid (6), the insulating layer (5) and the resistive layer (3) are squares into which the microtips (4) are positioned, the squares being interconnected through thin conductive bridges (8) for the grid (6) and through resistive bars (10) to form lattices, each pixel (7) being formed by a plurality of lattices, and each square bearing several microtips (4).
Claim 4
Dependent Claim
71 words
The microtip fluorescent display screen of claim 2, wherein the grid (6) is made of niobium or aluminum having a thickness of approximately 400 nm, and wherein the resistive layer (3) is made of amorphous silicon having a resistance of approximately 100 megohms per square, four respective bars (10) with a length/width ratio of 2 allowing the access to each square lattice, the sides of the squares being approximately 25 micrometers.
Claim 5
Independent Claim
84 words
A method for manufacturing a fluorescent display screen cathode including microtips, including a supporting plate (1) bearing cathode conductors in meshed columns (2), a resistive layer (3) bearing microtips (4), an insulating layer (5) and a grid conductive layer (6) in rows, comprising the step of simultaneously etching the three upper grig layer (6), insulating layer (5) and resistive layer (3) according to a single perforated pattern defining both the grid rows and the access resistance to the microtips (4) through said resistive layer.
Claim 6
Independent Claim
84 words
A method for manufacturing a fluorescent display screen cathode including microtips, including a supporting plate (1) bearing cathode conductors in meshed columns (2), a resistive layer (3) bearing microtips (4), an insulating layer (5) and a grid conductive layer (6) in rows, comprising the step of simultaneously etching the three upper grig layer (6), insulating layer (5) and resistive layer (3) according to a single perforated pattern defining both the grid rows and the access resistance to the microtips (4) through said resistive layer.
Claim 7
Dependent Claim
10 words
The method of claim 4, including only three etching steps.
Claim 8
Dependent Claim
95 words
The method of claim 5, including the following steps: depositing a cathode metal layer (11), etching meshed columns of conductors (2) in said metal layer through a first mask, depositing a resistive layer (3), an insulating layer (5), and a grid conductive layer (6), etching holes (12) for forming microtips (4) with a second mask, depositing microtips (4), simultaneously etching the grid layer (6), the insulating layer (5) and the resistive layer (3) in perforated rows with a third and last mask which also serves to define the contact areas of the rows and columns.
Claim 9
Dependent Claim
40 words
The method of claim 4, wherein the pattern or the grid conductive layer (6), insulating layer (5) and resistive layer (3) is formed by squares mutually interconnected by thin bridges, each pixel (7) being constituted by a plurality of squares.
Claim 10
Dependent Claim
56 words
The method of claim 7, wherein the path of the current flowing through the resistive layer (3), from the sides of a mesh of a column conductor (2) to the base of a microtip (4) is defined by four resistive bars (10) surrounding each square and formed simultaneously as conductive bridges (8) of the grid (6).
Claim 11
Dependent Claim
54 words
The method of claim 7, wherein the respective sizes of the meshes of the column conductors (2) and of the grid squares are selected so that empty areas (9) remain between said squares and said meshes allowing the observation through the structure of the cathode of the phosphor elements formed on an anode plate.
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) | 1999-11-12 | 2000-05-13 | 2000-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-12 | 2004-05-13 | 2004-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-12 | 2008-05-13 | 2008-11-12 | $7700.00 | Window Closed / Lapsed |