The Scophony scanner

The Scophony scanner uses the same optical elements as the more familiar flying spot scanner: a rotating polygon mirror, an acoustooptic (A/0) modulator, and a laser light source. The flying spot scanner is designed to construct its image a pixel at a time; no more than one pixel is illuminated at any given instant. The Scophony scanner is designed to image a broad swath of the A/0 modulator's acoustic pulses onto the photoreceptor. Many pixels are illuminated at any given instant in the Scophony scanner. The acoustic pulse image motion is frozen in place by a compensating scanning action. The result is a scanner with a coherent imaging response. This coherent response implies that the optical phase of a given pixel profoundly influences the formation of neighboring pixels. The optical phase at the scanner image plane is driven by the electronic phase of the video signal applied to the A/0 modulator. This coherent response enables electronic manipulation of the video drive signal to have significant impact on the optical imaging performance of the scanner. Two electronic manipulation schemes are proposed for doubling the resolution of the Scophony scanner, one scheme for analog video signals, and one scheme for binary digital video signals. Each scheme gives superior contrast ratio performance compared with the flying spot scanner.