Colour picture tube (colour television tube) with an in-line electron gun which has three astigmatic lenses

摘要

An improved colour picture tube (10) contains a screen (22) and an in-line gun (26) in order to generate three electron beams (28), located in one plane, and to direct them along separate paths onto a screen. The electron gun contains electrodes which provide a beam-shaping region, a pre-focusing region and a main focusing region. The beam-shaping region of the gun contains a cathode (34), a G1 electrode (36), a G2 electrode (38) and a first part (60) of a G3 electrode (40). The pre-focusing region contains a second part (62) of the G3 electrode, a G4 electrode and a first part (68, 70) of a G5 electrode (44). The main focusing region contains a second part (72) of the G5 electrode and a G6 electrode (40). The improvement consists in that the beam-shaping region, the pre-focusing region and the main focusing region are in each case astigmatic. <IMAGE>