METHOD OF PROVIDING REFERENCE POINTS FOR THE MAGNETIC DEFLECTION UNIT OF A COLOUR DISPLAY TUBE, DEVICE FOR CARRYING OUT SUCH A METHOD, AND DISPLAY TUBE PROVIDED WITH REFERENCE POINTS ACCORDING TO THE METHOD OR BY MEANS OF THE DEVICE

摘要

The place and the direction of the electron beam of the central gun of an "in-line" tube are fixed by the line through a) the centre of a dynamic magnetic multipole which is provided around the neck of the tube in such manner that a colour pure dot is displayed on the display screen, and b) said dot on the display screen. Reference points related with said line are provided on the envelope against which the deflection unit is placed in such manner that its axis coincides with the line.