(19)
(11) EP 0 066 948 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.01.1983 Bulletin 1983/02

(43) Date of publication A2:
15.12.1982 Bulletin 1982/50

(21) Application number: 82302091

(22) Date of filing: 23.04.1982
(84) Designated Contracting States:
DE FR NL

(30) Priority: 19.05.1981 GB 8115377

(71) Applicant: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and
 ()

(72) Inventors:
  • Glasper, John Lewis
     ()
  • Robbins, David John
     ()

   


(54) Cathode ray tubes


(57) A cathode ray tube (1) (C.R.T.) comprises an envelope (2) having a fibre optic face plate (4) formed of light transmitting fibres (6) in a light absorbing matrix (7). Islets (8) of phosphor are arranged in register with the fibres (6). A thin electrically conducting layer (9) covers the islets and inner face of the face plate. The islets (8) are formed by covering the face plate (4) with a phosphor layer (5) then a layer of photo resist (10). The photo resist (10) is exposed to light transmitted along the fibres (6) thereby providing a mask for removing phosphor not in register with a fibre (6). The photo resist may be a single layer of negative resist, or a layer of negative resist follewed by a barrier layer and a layer of positive resist.






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