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US4661373A Expired / Lapsed US ⏱️ 0.0 years remaining

Dispersion electroluminescent element

Assignee: Alps Alpine Co Ltd
•
Filing: 1986-01-06
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Granted: 1987-04-28
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Expires: 2006-01-06
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Abstract

Abstract A dispersion electroluminescence element comprising a fluorescent powder layer which is formed on a transparent electrode by coating process and a counter electrode facing said transparent electrode with said fluorescent powder layer interposed therebetween, characterized in that the fluorescent particles in the fluorescent material layer are coated with copper after forming the layer on the transparent electrode and then laminating the counter electrode thereon.

Inventors

  • 👤 Yoshinori Kato
  • 👤 Masami Igarashi
  • 👤 Yoshimi Kamijo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 20:23
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/02; H; H05; H05B; H05B33/00; H05B33/12; H05B33/14; H05B33/20; Y; Y10; Y10S; Y10S428/00; Y10S428/917

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 172 words
In a method for forming a dispersion electroluminescent element of the type comprising a transparent electrode, a fluorescent powder layer coated on said transparent electrode, and a counter electrode spaced apart from said transparent electrode by said fluorescent powder layer, the improvement comprising the steps of first forming the fluorescent powder layer by suspending the fluorescent particles of said fluorescent powder layer in a binder with an excess amount of binder being provided as a binder layer in the vicinity of said transparent electrode, then immersing the fluorescent particles suspended in the binder in a copper solution such that the particles are coated with copper to a lesser extent on their sides facing toward said transparent electrode due to the excess binder layer in the vicinity of said transparent electrode than toward said counter electrode, whereby the resultant electrolumienscent element is formed with much less or no copper coating on the sides of the fluorescent particles facing the transparent electrode and a subsequent copper diffusion forming step can be minimized or avoided.
Claim 2
Dependent Claim 172 words
In a method for forming a dispersion electroluminescent element of the type comprising a transparent electrode, a fluorescent powder layer coated on said transparent electrode, and a counter electrode spaced apart from said transparent electrode by said fluorescent powder layer, the improvement comprising the steps of first forming the fluorescent powder layer by suspending the fluorescent particles of said fluorescent powder layer in a binder with an excess amount of binder being provided as a binder layer in the vicinity of said transparent electrode, then immersing the fluorescent particles suspended in the binder in a copper solution such that the particles are coated with copper to a lesser extent on their sides facing toward said transparent electrode due to the excess binder layer in the vicinity of said transparent electrode than toward said counter electrode, whereby the resultant electrolumienscent element is formed with much less or no copper coating on the sides of the fluorescent particles facing the transparent electrode and a subsequent copper diffusion forming step can be minimized or avoided.
Claim 3
Dependent Claim 98 words
The method for forming a dispersion electroluminescence element according to claim 1, wherein said fluorescent material layer is formed by calcining zinc sulfide powder containing 0.5% of manganese and 0.05% of copper as activators at a temperature of 900° to 950° C. in an atmosphere of nitrogen or hydrogen sulfide for 1 hour, dispersing the powder into a binder in excess of the amount required to bind the particles, applying the dispersion to the transparent electrode, and then drying the element after it is allowed to stand so that the excess binder is gathered toward the transparent electrode.
Claim 4
Dependent Claim 31 words
The method for forming a dispersion electroluminescence element according to claim 1, wherein said binder comprises ethyl cellulose and terpineol in the proportion of the former to the latter of 1:20.
Claim 5
Dependent Claim 30 words
The method for forming a dispersion electroluminescence element according to claim 2, wherein said drying is conducted so that the thickness of the dried film reaches 15 to 30 μm.
Claim 6
Dependent Claim 54 words
The method for forming a dispersion electroluminescence element according to claim 1, wherein the formation of copper coat is executed by immersing the fluorescent material layer in a 0.1% aqueous solution of copper chloride (II), withdrawing the layer therefrom, washing the layer with pure water several times, and then allowing the layer to dry.
Claim 7
Dependent Claim 34 words
The method for forming a dispersion electroluminescence element according to claim 5, wherein the time of immersion of the fluorescent material layer in the aqueous solution of copper chloride (II) is within 3 minutes.
Claim 8
Dependent Claim 27 words
The method for forming a dispersion electroluminescence element accoding to claim 1, wherein the counter electrode is formed by by vacuum-depositing aluminum on the fluorescent material layer.
Claim 9
Dependent Claim 27 words
The method for forming a dispersion electroluminescence element according to claim 1, wherein the mixing ratio of the binder to the fluorescent material is 1.6/1 or more.
Claim 10
Dependent Claim 11 words
A dispersion electroluminescent element formed by the method of claim 1.

References Cited (Backward Citations)

US2310852A Cited
US2675331A Cited
US2866878A Cited
US3775173A Cited
US4486499A Cited
US4376145A Cited
US4415471A Cited
US4500173A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-04-27 1990-10-27 1991-04-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-04-27 1994-10-27 1995-04-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-04-27 1998-10-27 1999-04-28 $7700.00 Window Closed / Lapsed

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