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US4529885A Expired / Lapsed US ⏱️ 0.0 years remaining

Direct current electroluminescent devices

Assignee: UK Secretary of State for Defence
•
Filing: 1982-12-01
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Granted: 1985-07-16
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Expires: 2002-12-01
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Abstract

Abstract A direct current electroluminescent device having a phosphor layer and coating electrodes, at least one of which is translucent, which has interposed between the phosphor layer and at least one of said electrodes a thin non-planar layer of an electrically non-conducting substance. The non-planar layer may have a cross section of undulating outline or may be a discontinuous layer, e.g. in the form of closely spaced dots. Preferably the non-planar layer is translucent and is arranged between the phosphor layer and a translucent electrode. Suitable materials for the non-planar layer include silicon monoxide, silicon dioxide, germanium dioxide, magnesium fluoride, cadmium fluoride, yttrium fluoride, yttrium oxide, zinc sulphide, copper sulphide.

Inventors

  • 👤 Michael S. Waite
  • 👤 Surjit S. Chadha
  • 👤 Weng Y. Leong

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 19:50
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/22

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 45 words
A direct currect electroluminescent device comprising (a) a phosphor layer, (b) coacting electrodes, at least one of said electrodes being planar and translucent, and (c) a thin non-planar layer of an electrically non-conducting substance interposed between said phosphor layer and said at least one electrode.
Claim 2
Dependent Claim 45 words
A direct currect electroluminescent device comprising (a) a phosphor layer, (b) coacting electrodes, at least one of said electrodes being planar and translucent, and (c) a thin non-planar layer of an electrically non-conducting substance interposed between said phosphor layer and said at least one electrode.
Claim 3
Dependent Claim 18 words
A device according to claim 1 in which the non-planar layer has a cross section of undulating outline.
Claim 4
Dependent Claim 15 words
A device according to claim 1 in which the non-planar layer is a discontinuous layer.
Claim 5
Dependent Claim 23 words
A device according to claim 3 in which the non-planar layer is in the form of closely spaced dots of said non-conducting substance.
Claim 6
Dependent Claim 22 words
A device according to claim 1 in which the maximum thickness of the non-planar layer is not more than about one micrometer.
Claim 7
Dependent Claim 19 words
A device according to claim 2 in which the minimum thickness of the non-planar layer is about fifty nanometers.
Claim 8
Dependent Claim 26 words
A device according to claim 1 in which the non-planar layer is translucent and is arranged between the phosphor layer and an electrode which is translucent.
Claim 9
Dependent Claim 35 words
A device according to claim 1 in which the non-planar layer consists of at least one of silicon monoxide, silicon dioxide, germanium dioxide, magnesium fluoride, cadmium fluoride, yttrium fluoride, yttrium oxide, zinc sulphide, copper sulphide.
Claim 10
Independent Claim 55 words
A method of producing an electroluminescent device having a non-planar layer of an electrically non-conducting substance which includes the steps of evaporating particles of a selected non-conducting substance and directing the evaporated particles onto a substrate which is part of the device to be produced, while controlling the distribution of said particles on the substrate.
Claim 11
Independent Claim 55 words
A method of producing an electroluminescent device having a non-planar layer of an electrically non-conducting substance which includes the steps of evaporating particles of a selected non-conducting substance and directing the evaporated particles onto a substrate which is part of the device to be produced, while controlling the distribution of said particles on the substrate.
Claim 12
Dependent Claim 34 words
A method according to claim 9 in which an undulating layer is produced on the substrate by directing the evaporated particles onto the substrate at an angle thereto differing substantially from a right angle.
Claim 13
Dependent Claim 39 words
A method according to claim 10 in which the evaporated particles are directed onto the substrate at an angle in the range from about 10° to about 40° from a normal to the substrate where the particles are deposited.
Claim 14
Dependent Claim 32 words
A method according to claim 9 in which a discontinuous layer of closely spaced dots is produced on the substrate by directing the evaporated particles onto the substrate through a perforate mask.
Claim 15
Dependent Claim 55 words
A direct current electroluminescent device comprising (a) a first planar and translucent electrode, (b) a thin non-planar layer of an electrically non-conducting substance formed on said first electrode, (c) a second electrode spaced from said non-planar layer, and (d) a phosphor layer disposed between and in contact with said non-planar layer and said second electrode.
Claim 16
Dependent Claim 55 words
A direct current electroluminescent device comprising (a) a first planar and translucent electrode, (b) a thin non-planar layer of an electrically non-conducting substance formed on said first electrode, (c) a second electrode spaced from said non-planar layer, and (d) a phosphor layer disposed between and in contact with said non-planar layer and said second electrode.
Claim 17
Dependent Claim 15 words
A device as in claim 13 wherein said non-planar layer has an undulating cross-sectional outline.
Claim 18
Dependent Claim 14 words
A device as in claim 13 wherein said non-planar layer is a discontinuous layer.
Claim 19
Dependent Claim 21 words
A device as in claim 15 wherein said non-planar layer includes a plurality of closely spaced dots of said non-conducting substance.

References Cited (Backward Citations)

US2829265A Cited
US3731353A Cited
US4015166A Cited
GB1407098A Cited
GB1568111A Cited
JPS53138751A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-07-15 1989-01-14 1989-07-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-07-15 1993-01-14 1993-07-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-07-15 1997-01-14 1997-07-16 $7700.00 Window Closed / Lapsed

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