Global Patent Index - EP 0178857 A2

EP 0178857 A2 19860423 - Electron gun.

Title (en)

Electron gun.

Title (de)

Elektronenkanone.

Title (fr)

Canon à électrons.

Publication

EP 0178857 A2 19860423 (EN)

Application

EP 85307284 A 19851011

Priority

US 66260384 A 19841019

Abstract (en)

An inline electron gun (26:26 min ) for a cathode-ray tube (8) includes an improved beam forming region comprising three cathodes (34), a control grid (36) and a novel screen grid electrode means (38,38 min ), the latter comprising two spaced apart metal members (G2a, G2b;G2a min ,G2b min ). In one embodiment (26), the first member (G2a) closest to the control grid is relatively thick and has three slots (52) formed in one surface thereof facing away from the control grid. Circular apertures (54) are formed within the slots and extend through the body of the first member. The second member (G2b) has three circular apertures (56) therethrough aligned with the circular apertures in the first member. When a dynamic signal is superimposed on the DC bias voltage and applied to the second member, the first member shields the control grid from the dynamic signal so that little or no brightness modulation occurs. In a second embodiment (26 min ), the first (G2a min ) and second (G2b min ) members of the screen grid (38 min ) are structurally interchanged. In a third embodiment, the first (G2a) and the second (G2b) members have orthogonally disposed rectangular slots formed in facing surfaces.

IPC 1-7

H01J 29/50

IPC 8 full level

H01J 29/50 (2006.01)

CPC (source: EP KR)

H01J 29/48 (2013.01 - KR); H01J 29/503 (2013.01 - EP); H01J 2229/4841 (2013.01 - EP); H01J 2229/4865 (2013.01 - EP); H01J 2229/4872 (2013.01 - EP)

Designated contracting state (EPC)

DE FR GB IT

DOCDB simple family (publication)

EP 0178857 A2 19860423; EP 0178857 A3 19860820; EP 0178857 B1 19890830; BR 8505150 A 19860729; CA 1237464 A 19880531; CN 85107200 A 19860723; CS 719485 A2 19891114; DD 238473 A5 19860820; DE 3572748 D1 19891005; IN 165574 B 19891118; JP S6199251 A 19860517; KR 860003644 A 19860528

DOCDB simple family (application)

EP 85307284 A 19851011; BR 8505150 A 19851016; CA 491668 A 19850926; CN 85107200 A 19850926; CS 719485 A 19851008; DD 28183585 A 19851017; DE 3572748 T 19851011; IN 863CA1985 A 19851203; JP 23439385 A 19851018; KR 850007609 A 19851016