DAVISSON CATHODE RAY TELEVISION TUBE 



857 



Beyond the aperture 5' the electron beam enters a projection lens sys- 

 tem designed to project an enlarged electron image of 5' onto the fluores- 

 cent screen of the tube. In order to avoid further modulation of the beam 



VERTICALLY 



DEFLECTING 



PLATES 



HORIZONTALLY 

 DEFLECTING o 

 PLATES 



APERTURE S--^ 



APERTURE S- 



M2+0 

 MODULATING 

 PLATES,, ^ 

 Mi+o- 



P2"— 



i:t = 



APERTURE S- 



P,___, 



*-oP2±0V 

 OP4-66OOV ±200V 



-0M2- 

 ■oM,'- 



^ Pa -7500 V± 200 V 

 ■oCP,CC-200V 



CC; 



^ |U oCP2«* 200V +100V 



J] |W— ^-<'CP,«^-200V ±100V 



<C 



■op, ^ 



-o _ 



-8000 V ± 1000 V 

 -10,000 V 



■oP/-^ -10,500 V ±250V 



Fig. 2 — Schematic diagram of electron optical system. 



in the projection lens system it is essential that the beam be maintained 

 parallel with the tube axis and not be deflected by modulation as in Fig. 

 1(b). To accomplish this a second pair of modulating plates M2 and M2 



