Video monitor which superimposes a high frequency periodic wave over signals to vertical deflection plates to increase display quality in low resolution modes

摘要

A video monitor including logic circuitry which superimposes a high frequency periodic wave on the vertical positioning provided by the monitor's vertical deflection plates in low resolution modes. The waveform operates to slightly and periodically adjust the electromagnetic output of the vertical deflection plates, enabling the electron beam to pass through the shadow mask in a plurality of locations. In low resolution modes, the electron beam passes through additional holes in the shadow mask line that formerly presented a black stripe, thus enabling additional pixels to be struck and causing the black lines to disappear. This creates the appearance of a larger electron beam without changing the electron gun or adding additional deflection hardware.