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US4264408A Expired / Lapsed US ⏱️ 0.0 years remaining

Methods for applying phosphors particularly adapted for intagliated phosphor screens

Assignee: ITT Inc
•
Filing: 1979-06-13
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Granted: 1981-04-28
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Expires: 1999-06-13
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Abstract

Abstract A method is described for applying dry phosphor particles on a substrate, such as an intagliated array of fiber optic rods, each etched to form a pit in the surface. In this technique a thin layer of a heated thermoplastic is formed on the surface of the substrate to uniformly coat the etched pits and receive the phosphor particles. The plastic film is heated to receive the particles which are deposited upon the plastic layer. The particles become embedded in the plastic. The plastic layer is removed and the screen is then secured with a binder to fix the particles within the etch pits or cells of the intagliated array.

Inventors

  • 👤 James D. Benham

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 02:06
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/20; H01J9/22; H01J9/227; C; C03; C03C; C03C25/00; H01J29/00; H01J29/86; H01J29/89; H01J29/892

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 148 words
A method of dry depositing phosphor particles on a substrate, said substrate having an intagliated surface comprising a honeycomb array of a plurality of fiber optic rods, each etched to form a pit in the surface manifesting said array, comprising the steps of: depositing a thin uniform layer of metal on said intagliated surface to metallize each of said etch pits, spin coating said intagliated surface of said substrate with a thin thermoplastic film to uniformly coat said metallized etch pits, heating the assembly to bake the film at a predetermined temperature to soften the same, depositing dry phosphor particles on the heated thermoplastic coated surface, removing said thermoplastic coating by heating said substrate at a higher temperature than said predetermined temperature to remove the thermoplastic to cause said particles to enter said metallized etch pits, binding the particles in place in said etch pits with a binder.
Claim 2
Independent Claim 148 words
A method of dry depositing phosphor particles on a substrate, said substrate having an intagliated surface comprising a honeycomb array of a plurality of fiber optic rods, each etched to form a pit in the surface manifesting said array, comprising the steps of: depositing a thin uniform layer of metal on said intagliated surface to metallize each of said etch pits, spin coating said intagliated surface of said substrate with a thin thermoplastic film to uniformly coat said metallized etch pits, heating the assembly to bake the film at a predetermined temperature to soften the same, depositing dry phosphor particles on the heated thermoplastic coated surface, removing said thermoplastic coating by heating said substrate at a higher temperature than said predetermined temperature to remove the thermoplastic to cause said particles to enter said metallized etch pits, binding the particles in place in said etch pits with a binder.
Claim 3
Dependent Claim 33 words
The method according to claim 1 wherein said step of spin coating said intagliated surface is provided by uniformly applying a solution of a thermoplastic to said substrate and spinning the coated substrate.
Claim 4
Dependent Claim 13 words
The method according to claim 2 wherein said thermoplastic is an acrylic plastic.
Claim 5
Dependent Claim 30 words
The method according to claim 1 wherein the step of heating to soften the film includes heating the substrate to a temperature of about 220° C. for approximately five minutes.
Claim 6
Dependent Claim 28 words
The method according to claim 1 wherein the step of depositing phosphor particles includes depositing said particles having a diameter within the range of two to four microns.
Claim 7
Dependent Claim 33 words
The method according to claim 1 further including the step of rubbing said assembly after deposition of said particles to remove any excess particles prior to said step of removing said plastic coating.
Claim 8
Dependent Claim 35 words
The method according to claim 1 wherein the step of removing said plastic coating includes baking said substrate at a temperature of about 400° C. for a period of time sufficient to remove said coating.
Claim 9
Dependent Claim 29 words
The method according to claim 1 including the step of polishing said surface after removing said plastic coating to remove excess phosphor particles and to smooth said intagliated surface.
Claim 10
Dependent Claim 29 words
The method according to claim 1 wherein the step of binding said particles in place includes immersing said assembly in a silicate solution and then spin drying said assembly.
Claim 11
Dependent Claim 29 words
The method according to claim 9 wherein said silicate solution is a solution of potassium silicate and said assembly is immersed therein for a period of approximately five minutes.
Claim 12
Dependent Claim 37 words
The method according to claim 1 further including the steps of: lacquering said assembly after binding said particles thereto; and applying a thin opaque layer of aluminum to said surface of said assembly containing said phosphor particles.
Claim 13
Dependent Claim 15 words
The method according to claim 1 wherein said particles of phosphor are zinc sulfide particles.
Claim 14
Dependent Claim 16 words
The method according to claim 1 wherein said particles of phosphor are zinc cadmium sulfide particles.
Claim 15
Dependent Claim 26 words
The method according to claim 1 wherein said substrate is an intagliated fiber optic array adapted for use as a screen for an image intensifier tube.
Claim 16
Dependent Claim 31 words
The method according to claim 1 wherein said pits on said fiber optic surface are approximately between six to ten micrometers in diameter and between ten to twelve micrometers in depth.
Claim 17
Dependent Claim 43 words
The method according to claim 1 comprising the step of etching said pits in said fiber optic rods by inserting said array in an etchant solution at a temperature of about 50° C. for a period determined by the depth of said pit.
Claim 18
Dependent Claim 28 words
The method according to claim 16 wherein said etchant solution is a solution of an acid selected from the group consisting of hydrochloric, nitric, phosphoric or hydrofluoric acid.
Claim 19
Dependent Claim 18 words
The method according to claim 1 wherein said intagliated substrate is the screen of an image intensifier tube.
Claim 20
Independent Claim 141 words
A method of dry depositing phosphor particles on a surface of an intagliated substrate of the type consisting of a plurality of fused fiber optic cables, each having an etched aperture on a surface to formulate said intagliated surface, comprising the steps of: spin coating said intagliated surface with an acrylic plastic to uniformly coat said apertures with said plastic, heating said coated assembly to a temperature of about 200° C. for a period of approximately five minutes to bake and soften said plastic coating, uniformly applying dry phosphor particles to said plastic coated surface, baking said assembly at about 400° C. for a period of about one hour to remove said acrylic plastic coating to cause said particles to enter said etch pits, binding said phosphor particles in place in said pits by immersing said assembly in a silicate solution.
Claim 21
Independent Claim 141 words
A method of dry depositing phosphor particles on a surface of an intagliated substrate of the type consisting of a plurality of fused fiber optic cables, each having an etched aperture on a surface to formulate said intagliated surface, comprising the steps of: spin coating said intagliated surface with an acrylic plastic to uniformly coat said apertures with said plastic, heating said coated assembly to a temperature of about 200° C. for a period of approximately five minutes to bake and soften said plastic coating, uniformly applying dry phosphor particles to said plastic coated surface, baking said assembly at about 400° C. for a period of about one hour to remove said acrylic plastic coating to cause said particles to enter said etch pits, binding said phosphor particles in place in said pits by immersing said assembly in a silicate solution.
Claim 22
Dependent Claim 30 words
The method according to claim 19 wherein said step of binding includes immersing in a potassium silicate solution, soaking said substrate in said solution and thereafter spin drying said substrate.
Claim 23
Dependent Claim 24 words
The method according to claim 19 wherein said phosphor particles are between two to four microns in diameter and are fabricated from phosphor material.

References Cited (Backward Citations)

US2828216A Cited
US3139340A Cited
US3701658A Cited
US4025662A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-04-27 1984-10-27 1985-04-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-04-27 1988-10-27 1989-04-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-04-27 1992-10-27 1993-04-28 $7700.00 Window Closed / Lapsed

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