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US5072152A Expired / Lapsed US ⏱️ 0.0 years remaining

High brightness TFEL device and method of making same

Assignee: Planar Systems Inc
•
Filing: 1990-02-05
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Granted: 1991-12-10
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Expires: 2010-02-05
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Abstract

Abstract A TFEL device for producing a high brightness output comprises a substrate supporting a laminar thin film stack including a front electrode layer and a rear electrode layer sandwiching an electroluminescent laminate comprising an electroluminescent layer sandwiched by a pair of insulating layers. A thin film insulating layer is grown by evaporation on the glass substrate and produces a surface having a degree of roughness which is replicated by the remaining thin film layers. The surface contour at the interfaces between each of the thin film layers is convoluted which reduces internal light reflection and provides more light output at the front of the panel.

Inventors

  • 👤 Richard T. Tuenge
  • 👤 Christopher N. King

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 15:12
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/22; H05B33/10

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 94 words
A method of fabricating a TFEL device comprising the steps of: (a) forming a thin film insulating layer on a transparent planar substrate to create a roughened template surface; (b) depositing a transparent electrode layer on top of said thin film insulating layer so as to conform to the roughened template surface; (c) placing a thin film laminate electroluminescent structure on top of the transparent electrode layer so as to conform to the contour of the electrode layer; and (d) placing a rear electrode layer on top of the thin film laminate electroluminescent structure.
Claim 2
Independent Claim 94 words
A method of fabricating a TFEL device comprising the steps of: (a) forming a thin film insulating layer on a transparent planar substrate to create a roughened template surface; (b) depositing a transparent electrode layer on top of said thin film insulating layer so as to conform to the roughened template surface; (c) placing a thin film laminate electroluminescent structure on top of the transparent electrode layer so as to conform to the contour of the electrode layer; and (d) placing a rear electrode layer on top of the thin film laminate electroluminescent structure.
Claim 3
Dependent Claim 15 words
The method of claim 1 wherein the thin film insulating layer is formed by evaporation.
Claim 4
Dependent Claim 13 words
The method of claim 1 wherein the thin film insulating layer is ZnS.
Claim 5
Dependent Claim 17 words
The method of claim 1 wherein the thin film laminate includes an electroluminescent layer formed by sputtering.
Claim 6
Dependent Claim 18 words
The method of claim 2 wherein the surface roughness of the thin film insulating layer is approximately 1000Å.
Claim 7
Dependent Claim 86 words
A thin film electroluminescent device comprising: (a) a planar substrate; (b) a thin film stack comprising a front transparent electrode layer and a rear electrode layer sandwiching an electroluminescent laminate comprising a layer of electroluminescent phosphor film sandwiched between a pair of insulating layers; and (c) a transparent thin film insulating layer deposited by evaporation on said substrate between said stack and said substrate and having a surface roughness of approximately 1000Å which is substantially replicated by said thin film stack for reducing internal light reflection.
Claim 8
Dependent Claim 86 words
A thin film electroluminescent device comprising: (a) a planar substrate; (b) a thin film stack comprising a front transparent electrode layer and a rear electrode layer sandwiching an electroluminescent laminate comprising a layer of electroluminescent phosphor film sandwiched between a pair of insulating layers; and (c) a transparent thin film insulating layer deposited by evaporation on said substrate between said stack and said substrate and having a surface roughness of approximately 1000Å which is substantially replicated by said thin film stack for reducing internal light reflection.

References Cited (Backward Citations)

US4020389A Cited
JPS5415689A Cited
US4675092A Cited
US4728581A Cited
US4774435A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-12-09 1995-06-10 1995-12-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-12-09 1999-06-10 1999-12-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-12-09 2003-06-10 2003-12-10 $7700.00 Window Closed / Lapsed

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