(19)
(11) EP 0 067 507 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.05.1983 Bulletin 1983/18

(43) Date of publication A2:
22.12.1982 Bulletin 1982/51

(21) Application number: 82302090

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

(30) Priority: 19.05.1981 GB 8115379

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

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

   


(54) Cathode ray tube screens


(57) A cathode ray tube comprises an envelope (1) having a screen (3) of a single crystalline or polycrystalline material such as yttrium aluminium garnet. Dopants such as Tb3+, Eu3+, Ce3+ or Tm3+ are implanted to different depths or in different areas (7, 10) of the screen. Annealing the screen removes lattice damage caused by the implanting. Multicolour luminescence is obtained by scanning an electron beam over the differently doped areas (7, 10), or by varying the electron beam energy as it scans.






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