Abstract: A two dimensional array of image positions on the screen of an image converter is provided by switching the potentials applied to each of the deflector plates, which are arranged in pairs, one at a time in sequence, each step change in the applied potential for a given deflector plate being sufficient to shift the image position from one position to the next in the array. Pairs of plates can be arranged in orthogonal relationships. Shifting of image positions is performed in the intervals between shutter pulses and the durations of the shutter pulses and the inter-pulse intervals are individually adjustable. The converter includes a programmable memory for holding data words representing the said intervals and circuitry for converting these data words into timing signals for the shuttering and switching of the image converter.