(19)
(11) EP 0 452 789 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.02.1992 Bulletin 1992/07

(43) Date of publication A2:
23.10.1991 Bulletin 1991/43

(21) Application number: 91105658.8

(22) Date of filing: 10.04.1991
(51) International Patent Classification (IPC)5H01J 29/50, H01J 29/62
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 16.04.1990 US 509537

(71) Applicant: THOMSON CONSUMER ELECTRONICS, INC.
Indianapolis Indiana 46201 (US)

(72) Inventors:
  • Maninger, Loren Lee
    Lancaster, Pennsylvania (US)
  • Marks, Bruce George
    Lancaster, Pennsylvania (US)

(74) Representative: Einsel, Robert, Dipl.-Ing. 
Deutsche Thomson-Brandt GmbH Patent- und Lizenzabteilung Göttinger Chaussee 76
30453 Hannover
30453 Hannover (DE)


(56) References cited: : 
   
       


    (54) Color picture tube having inline electron gun with focus adjustment means


    (57) A color picture tube (10) has a viewing screen (22) and an electron gun (26) for generating and directing three inline electron beams, a center beam and two side beams, toward the screen. The gun includes electrodes that form three focus lenses. A first lens (L1) is located in a beam-forming region of the gun. A second lens (L2) includes at least one electrode (42) for providing asymmetrically-shaped beams to a third lens (L3). The third lens is a common main focus lens for all three beams. The improvement comprises one (48) of the electrodes (44,48) of the third lens being shaped to provide a major amount of focus correction for each individual electron beam, and the one electrode of the second lens including means (70,71,72) for providing the remaining amounts of focus correction needed to substantially totally correct each individual electron beam.





    Search report