Abstract: A polygon scanner utilizing a fluid film bearing and method for its use in a flat field imaging device having a relatively large format size, a very high scan rate and high resolution. The polygon scanner has a polygon scan optic connected to a motor, a fluid film bearing, and a windowed enclosure. Repeating cross-scan error components are mapped and actively corrected using a piezoelectric actuator to directly displace the laser element or using a mirror in the optical path that is tilted by means of an electro-optic device to influence a virtual displacement of the optical beam. The repeating components of in-scan errors are similarly, and independently, mapped and corrected by summing with the output of a phase detector in a line scan speed control system.

Abstract: An infrared image is formed on the surface of a light-sensitive silicon position sensor having four outer electrodes equally spaced around the periphery of the sensor and a central electrode. A bias voltage is applied between the outer electrodes and the central electrode. Changes in current at the central electrode is used to modulate the intensity of a CRO beam. A light beam is used to scan the surface of the sensor in a fixed pattern and the CRO beam is scanned in synchronism with the light beam. Thermal variations produced by the IR image modulate the CRO beam, producing a visual image on the CRO screen of the IR image formed on the sensor.