Deflector coil arrangement for colour CRT - has distance between coil and electron beam greatest at coil centre

摘要

Electron beam deflection accuracy is improved and beam deflection energy requirements reduced when the fields produced by the ends of the deflector coils are more powerful than the field in the centre. The coil arrangement and assembly (3) is placed on the c.r.t. to cover the area of transition between the tubular part (2) and the conical part (1). The coils are formed so that the assembly is closer to the tube parts (1,2) at the ends (4,5) than in the centre (6). In the centre there may be a gap (8) between coil and tube. The arrangement ensures that the distance between coil surface and beam (7) is less at the ends (a,b) than in the centre (c). The result is accurate beam positioning even at extreme deflection angles.PS.