A dynamic focus voltage generator is provided for a tensioned focus mask
of a cathode ray tube of video display. The tensioned focus mask includes
spaced apart strands and spaced apart crosswires separated from the
strands. A synchronizing signal at a horizontal deflection frequency is
used for generating a dynamic focus voltage component that varies in
accordance with a position of an electron beam on a screen of the cathode
ray tube. A synchronizing signal at a vertical deflection frequency is
used for generating a dynamic focus voltage component that varies in
accordance with the position of the electron beam on the screen of the
cathode ray tube. The time varying voltage components are combined with a
direct current voltage component for producing a dynamic focus voltage
between the strands and crosswires.