A versatile electrical shutter for optical pumping experiments
Electro-optical shutter for optical pumping experiments using Kerr cell controlled by high voltage modulator
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Electro-optical shutter for optical pumping experiments using Kerr cell controlled by high voltage modulator
Kerr cell-shuttered high speed stigmatic spectrograph for shock tube electron density distribution measurement
Surveyor camera double acting rotary solenoid actuated focal plane shutter utilizing two blades in parallelogram linkage
Combination shutter and filter-changing mechanism for spacecraft vidicon cameras
Event-triggered high speed spectrograph shutter, studying shock tube plasmas
Shutter design consists of two axially mounted spring driven rotating blades with two lenses mounted between the blades. Features include excellent repeatability and flash synchronization. Design permits packaging in small volume and is beneficial where focal distance, magnification, and exposure time are fixed.
Nonmechanical shutter utilizes nematic crystals to attenuate illumination, thus protecting light-sensitive devices such as vidicon or image orthicon tubes and phototubes. Opacity of liquid crystals is controlled by photosensor.
Thin metal shutter that is forced into angled optical slit isolates spectrograph from high speed shock tube both optically and mechanically so neither radiation nor particulate material enters spectrograph.
A new mathematical model is presented which describes the image produced by a focal plane shutter-equipped camera. The model is based upon the well-known collinearity condition equations and incorporates both the translational and rotational motion of the camera during the exposure interval. The first differentials of the model with respect to exposure interval, delta t, yield the general matrix expressions for image velocities which may be simplified to known cases. The exposure interval, delta t, may be replaced under certain circumstances with a function incorporating blind velocity and image position if desired. The model is tested using simulated Lunar Orbiter data and found to be computationally stable as well as providing excellent results, provided that some external information is available on the velocity parameters.
Device can operate in close-open-close mode. Beam splitter placed behind static-slit assembly allows use of more than one camera. Each frame in particular series may be conveniently varied in exposure time and spacing. This can be done independent of other frames in the series. In ''open'' position, shutter transmits light over wide wavelength range.
The construction and electrical circuit of a rotating photoshutter are described. The photoshutter can operate, using both stationary and expeditional astronomical instruments under one of three conditions: (1) short exposures from 0.01 to 0.06 sec, controlled by a mobile sector; (2) exposures from 1 sec and more, fixed by hand; and (3) exposures fixed by an electronic or electromechanical timer. The working aperture of the shutter is 150 x 150 mm.
When photographic equipment is miniaturized, in order to conserve weight and size for spacecraft use, by using wide angle, short focus lenses, a band-type central between-the-lens shutter must be used. The rectangular slot shape was the form with the highest optical efficiency. To overcome the problem of burrs caused in the punching out of the slots in a carbon steel band, a shape limited by arcs with radius equal to half the slot width is preferred.
Solar receiver turned off by movable reflective shutter. When reflective surface interposed across optical axis, incoming solar heat reflected back to concentrator for rejection into space.
The design requirements, the design, the assembly and alignment, and the test program for a shutter mechanism which must operate at cryogenic temperature and draw less than 1.0 milliwatt are discussed. The design solution to meet these requirements is a device that positions a mirror with repeated accuracy, has no wearing surfaces, and operates at 2.0 K. The unique feature of this device is the simplicity of the mechanism, thus obtaining high reliability.
System of shutters for dual-molecular-beam epitaxy apparatus delays start of one beam with respect to another. Used in pulsed-beam equipment for deposition of low-dislocation layers of InAs on GaAs substrates, system delays application of arsenic beam with respect to indium beam to assure proper stoichiometric proportions on newly forming InAs surface. Reflectance high-energy electron diffraction (RHEED) instrument used to monitor condition of evolving surface of deposit. RHEED signal used to time pulsing of molecular beams in way that minimizes density of defects and holds lattice constant of InAs to that of GaAs substrate.
The interface switching systems are discussed which are related to those used in the Space Shuttle ground control system, transmission systems, communications systems, and airborne radar electronic countermeasure systems. The main goal is to identify a need that exists throughout the comprehensive information processing and communications disciplines supporting the Space Shuttle and Space Station programs, and introduce one viable approach to satisfy that need. The proposed device, described in NASA patent entitled 'Optical Shutter Switch Matrix', is discussed.
A thermal vacuum box bakeout and certification allows orbital payloads to be cleaned and certified when the background TQCM measurements (a measure of how much molecular contamination is on a payload or chamber) are unacceptable or unmanageable in the standard thermal vacuum chamber. The box bakeout procedure is usually performed in 4 steps: bakeout the box, certify the box, bake out the payload, and finally certify the payload. In the procedure's current setup, the contaminant conduction hole ("lid") is initially open and a vacuum chamber break must occur between the bakeout and certification phases to close the box from the vacuum chamber. This exposure is necessary to allow the outgassed contaminants to escape the box's volume rapidly during bakeout phase, but payload certification isn't usually performed while the lid is still open, because it exposes the payload, TQCM, and box volume to chamber contaminants. The Remotely Operated Bakeout Box Shutter (ROBBS) is a new facility design and will allow the remote closure of the contamination hole while the chamber is still under vacuum, and with little or no time to do so.
This paper describes the design requirements, the design, the assembly and alignment, and the test program for a shutter mechanism which must operate at cryogenic temperature and draw less than 1.0 milliwatt. The design solution to meet these requirements is a device that positions a mirror with repeated accuracy, has no wearing surfaces and operates at 2.0 K. The unique feature of this device is the simplicity of the mechanism, thus obtaining high reliability.