Global Patent Index - EP 0318113 A3

EP 0318113 A3 19890913 - CATHODE RAY TUBE DISPLAY SYSTEM

Title (en)

CATHODE RAY TUBE DISPLAY SYSTEM

Publication

EP 0318113 A3 19890913 (EN)

Application

EP 88202655 A 19881124

Priority

GB 8727565 A 19871125

Abstract (en)

[origin: EP0318113A2] A CRT display system in which an electron beam (32) is directed in a plane substantially parallel to a faceplate (14) carrying a phosphor screen (16) the beam (32) being deflected towards the screen. The position of the beam is controlled to correct for deviation caused, for example, by the influence of ambient magnetic fields. Sensor devices (50, 51) periodically detect during the tube operation deviation of the beam from the desired plane and control deflector electrodes (37) which return the beam to the desired plane. Twisting and lateral shifting of the scanning beam can also be corrected. Beam position sensing is accomplished by overscanning the beam towards the sensor devices during, for example, field blanking periods, so as not to interfere with the display picture.

IPC 1-7

H01J 29/46; H01J 29/54; H01J 31/12; H01J 29/56

IPC 8 full level

H01J 29/46 (2006.01); H01J 29/56 (2006.01); H01J 29/74 (2006.01); H01J 31/12 (2006.01); H01J 31/20 (2006.01)

CPC (source: EP)

H01J 29/56 (2013.01); H01J 29/74 (2013.01); H01J 31/124 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR GB IT

DOCDB simple family (publication)

EP 0318113 A2 19890531; EP 0318113 A3 19890913; GB 2213029 A 19890802; GB 8727565 D0 19871231; JP H01167939 A 19890703

DOCDB simple family (application)

EP 88202655 A 19881124; GB 8727565 A 19871125; JP 29372988 A 19881122