We shall now describe a device for the focusing of a beam of electrons in a tube - image and to adjust this focusing we shall now describe

摘要

The invention relates to a device for we shall now describe the focussing of a beam of electrons in a tube - image having a set of an electron gun in order to produce a beam of electrons, the beam forming impact on a display screen in order to excite a certain number of elements of phosphorus, the detection device comprising a means in order to deflect the beam through the screen in order to produce the excitation of the elements of phosphorus in a predetermined. / p & & p & according to the invention, a means 17 detected the output of the elements of phosphorus and a means 20, 21, 22 which is sensitive to the output detected, the precursor, the variation of a signal indicating the condition for focusing the beam of electrons. / p & & p & the invention applies particularly to the television.