公开(公告)号：GB2264587A

公开(公告)日：1993-09-01

申请号：GB9203771

申请日：1992-02-21

Applicant: IBM

Inventor： GIBBS TERENCE KEITH ,  LUCK GRAHAM ,  EAGLE DAVID JOHN ,  BATEMAN ANTHONY JOHN ,  LANHAM TONY ERIC

IPC: H01J29/00 ,  H01J29/06 ,  H01J29/86 ,  H01J29/88

Abstract: In a cathode ray display tube the front of the display screen (20) is shielded from the electric fields generated by the electromagnetic deflection coils (40) by an electrically conductive extension (60') of the usually provided exterior conductive coating 60 on the tube funnel, the extension coating (60') being disposed between the deflection coils (40) and the cathode ray tube envelope (10). Preferably a frustoconical insulating insert 90 electrically insulates the deflection coils from the coating extension 60'. Alternatively, Fig. 3 (not shown), the coating 60 is effectively extended by a conductive coating (62), on the inner face of a flexible plastics frustoconical insert (61), in electrical contact with and secured to the coating 60.