Luminescent screens utilizing nonluminescent separator layers

• US 3,294,569 A
• Filed: 12/12/1962
• Issued: 12/27/1966
• Est. Priority Date: 12/12/1962
• Status: Expired due to Term

• Current Assignee: Milton Thomsen Soren, Paul J. Messineo
• Original Assignee: Milton Thomsen Soren, Paul J. Messineo
• Inventors: Messineo, Paul J., MILTON THOMSEN SOREN
• Application Number:
  US04/244,201
• Time in Patent Office: 1,476 Days
• US Class Current: 428/328
• CPC Class Codes: H01J 29/26 with superimposed luminescent layers
• CPC Class Codes: H01J 29/32 with adjacent dots or lines of different luminescent material, e.g. for colour television
• CPC Class Codes: H01J 9/22 Applying luminescent coatings
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A luminescent screen comprises superimposed layers of a first phosphor, a non-luminescent material, and a second phosphor, the nonluminescent material being formed by poisioning a surface of one of the phosphor layers. The screen may be built up of a stack of continuous layers (Fig. 3, not shown), or it may be coated with a layer of phosphor particles, each particle being multi-coated, and may be used in a colour television display tube, with one or more electron guns, the energy of the electron beam determining the beam'"'"'s penetration, and hence the colour emitted. In an example, a blue-emitting silver activated zinc sulphide is surface poisoned by coating with a nickel sulphide and firing, and is then coated with a second, green-emitting phosphor layer, a separator layer and finally a red-emitting phosphor layer. Numerous classes of phosphor are mentioned, poisoned by iron, cobalt or nickel, and separator materials mentioned are silica, titanium dioxide, mica, bentonate, talc and vanadium oxide.

Claims

1. A LUMINESCENT SCREEN COMPRISING A SUBSTRATE COATED WITH A LAYER OF PHOSPHOR PARTICLES, EACH OF SAID PARTICLES COMPRISED OF:

(A) A CORE OF A FIRST PHOSPHOR HAVING A SURFACE SKIN LAYER THEREOF POISONED TO PROVIDE A NON-LUMINESCENT SEPARATOR LAYER SURROUNDING SAID CORE, (B) AND A SECOND AND DIFFERENT PHOSPHOR LAYER SURROUNDING SAID SEPARATOR LAYER.