Abstract: An infrared video camera system comprises an uncooled infrared sensor mounted and a thermally conductive thin walled radiation shield for shielding radiation from reaching an active surface of the uncooled infrared sensor. A TEC maintains the sensor active surface and the radiation shield at a substantially constant temperature. The uncooled infrared sensor and radiation shield are further housed in a hollow thermally conductive vacuum cover which is vacuum sealed with a base assembly and includes a vacuum sealed infrared transparent window in an aperture at a top end of the vacuum cover for allowing infrared radiation to reach the active surface and for forming a vacuum chamber enclosing the infrared sensor and radiation shield. A relay optical cell mounted to a camera body comprises at least one optical element for relaying an image formed at its entrance onto the active surface.

Abstract: A dual-mode resonant scanning system comprising an electronic control circuit and a dual-mode resonant mechanical scanner to produce an essentially triangular scan pattern. The dual-mode mechanical scanner is mechanically tuned to simultaneously oscillate at a predetermined third harmonic frequency and the free running fundamental thereof. The electronic control circuit drives the mechanical scanner to oscillate at the exact fundamental frequency of the predetermined third harmonic frequency and phase locks the fundamental oscillation to the third harmonic oscillation. The dual-mode resonant mechanical scanner includes an optical scanning element having a first mass, a second mass, at least one torsion rod, a rotational actuator and a mechanical ground designed and integrated together such that the mechanical scanner is self resonant at the predetermined third harmonic frequency and at or within a few hertz of the exact fundamental frequency of the predetermined third harmonic frequency.

Abstract: A scan converter circuit for use in a imaging system that uses a sinusoidally oscillating scanning reflector for scanning an object and a constant rate scanned display monitor for displaying an image of the object. The circuit enables a variable time rate of sampling of picture elements in the object field to match a desired constant display rate of picture elements in the CRT display monitor. The circuit comprises a constant rate VCO clock and a sampling clock that produces periodically variable rate pulses, the periodicity of which being phase locked with zero crossings of the oscillating reflector and wherein the pulses are derived from the constant rate VCO clock. The sampling clock enables an image sensor to sample the radiance levels at a rate which varies with the sinusoidal sweep speed of the oscillating reflector.