Abstract: A zoom lens comprising a first lens unit of positive refractive power for focusing, a second unit of negative refractive power movable for zooming in a mono-direction throughout, a third unit of positive refractive power movable for zooming in the opposite mono-direction to that of movement of the second unit, and a fourth unit of positive refractive power having an image forming function which is held stationary during zooming, with a diaphragm being arranged in between the second and third units to be stationary.
Abstract: A detonator-activated ball shutter for closing an aperture in about 300.mu. seconds. The ball shutter containing an aperture through which light, etc., passes, is closed by firing a detonator which propels a projectile for rotating the ball shutter, thereby blocking passage through the aperture.
Type:
Grant
Filed:
May 14, 1981
Date of Patent:
August 16, 1983
Inventors:
Roy A. McWilliams, William G. von Holle
Abstract: Photometer circuitry includes a capacitor discharge means for establishing a time period related to the light absorption properties of a test sample. The time period is used, in conjunction with a frequency generator to drive a digital counter to provide a digital indication of light absorption.
Abstract: A multifrequency laser oscillator which generates coherent light of two closely adjacent optical frequencies in rapid succession for recording contour holograms by the double exposure technique. The two light frequencies are selected by an optical intercavity frequency selector which is rotatable to a first position to select one frequency and to a second position to select the other frequency. The described laser oscillators have a ruby lasing medium and lase at the R.sub.1 and R.sub.2 transitions of the ruby resonant fluorescence.
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