device for reducing magnetic feltstyrka in nerheten device with katodstraleror with magnetic avlenkning

摘要

Apparatus of the type picture screen terminals and the like comprising a cathode ray tube (CRT) operating with electromagnetic deflection of the electron ray. In an area in front of the screen (2) there appears a leakage field (BL/D) from the deflection assembly (4) the presence of which is considered injurious to the health of persons within the area. The invention indicates a solution of the problem of how to suppress this field by means of a compensating field (BC) in such a way that the compensation field does not generate a disturbing field intensity on other sides of the apparatus. This is achieved by means of windings (7, 8) generating the compensating field (BC) and located in or near the plane of screen (2). The two fields shall be mutually antiparallel, synchronous and have substantially the same field intensity.