Abstract: The first plasma discharge chamber of the dual discharge plasma device contains an electron emitter and a first anode and contains gas at a sufficiently high pressure that the discharge voltage in the first chamber is below the sputtering threshold. The second chamber has a main anode and receives a plume of plasma from the first chamber. The main anode operates at a voltage above the sputtering threshold with a respect to the first anode and the gas in the second chamber is at a low enough pressure for a conventional low pressure plasma discharge which is used as an ion source.
Abstract: In an apparatus for examining a body by means of penetrating radiation a source is arranged to direct radiation through the body and a plurality of detectors are arranged to receive it thereafter. The source and detector are arranged to scan the body to obtain data for use in obtaining a distribution of absorption of the radiation for part of the body. For correction for differences in the relative sensitivities of the detectors they are arranged in pairs to examine radiation along substantially identical paths and for correction for drift each detector is caused to examine a substantially identical path at different times.
Abstract: Apparatus and method for the tomographic examination of planar sections of an object is disclosed which includes a plurality of sources spaced about an object at fixed intervals which emit a set of planar beams of penetrating radiation, such as X-rays or gamma rays, through a planar section of the object and a plurality of self-collimating detector arrays positioned to receive only photons of radiation which pass through the planar section of the object from the source directly opposite the array. The sources and detector arrays are mounted on a mounting apparatus to prevent movement relative to each other. Each of the detector arrays includes a plurality of self-collimating detectors which count the number of individual primary radiation photons passing through the object along the path from the source to the detector without absorption or deflection.
February 21, 1978
Date of Patent:
August 18, 1981
Ira Lon Morgan, E. C. George Sudarshan
Ira L. Morgan, E. C. George Sudarshan, Alvin L. Mitchell, James P. Coose, Hunter D. Ellinger, James W. Jagger
Abstract: There is provided polychromatic X-ray source used in a polychromatic X-ray diffraction apparatus, in which polychromatic X-rays are cast upon a sample to be analyzed, the energies of the X-rays diffracted from the crystallographic planes of the sample are measured and the physical properties of the sample are detected on the basis of the measured energies. The polychromatic X-ray source has a container made of radiation shielding material and having an X-ray outlet channel and the container contains therein a radionuclide for emitting radioactive rays and a substance for scattering and absorbing the radioactive rays emitted from the substance so as to obtain polychromatic X-rays. The polychromatic X-rays emitted from the substance travel through the X-ray outlet channel and are then made parallel through a Soller slit to be cast upon the sample. A slide door is provided in the channel so as to block the polychromatic X-rays if necessary.
Abstract: A rotational direction detection device is disclosed which has a single permanent magnet rotatable in response to the rotation of a rotary shaft. A magnetic field sensor is composed of a plurality of magnetic field detecting elements responsive to a rotating magnetic field produced by the rotation of the permanent magnet for generating an output representative of the rotation of the rotary shaft. The magnetic field detecting elements are arranged so that signals developed by at least two such elements differ in phase by a phase angle of other than 0 degree and 180 degrees. A rotary condition detector is responsive to the output of the magnetic field sensor for determining the rotational direction of the rotary shaft.
Abstract: An irradiation apparatus having a housing, a reflector and a source of ultraviolet radiation. The irradiation apparatus has a timing mechanism detachably located within the housing, the timing mechanism being an integral portion of the circuit which supplies power from a power source to the ultraviolet radiation source. The timer is adapted to be removed from the housing and attached to the housing by means of a cord having a non-standard plug to allow the lamp to be operated by means of the timer from a remote position.
Abstract: A computerized tomography system and method using penetrating radiation having a radiation source for radiating penetrating radiation into the interior of a thin sliced layer portion of a subject, in a manner that it expands substantially in a fanned fashion, a detector for substantially dividing the radiation after passing through said sliced layer portion into a plurality of radiation beams diverging at a defined angle, thereby detecting the intensity of said beams, a moving unit for substantially linearly scanning each of said beams at least once in a direction transverse of said sliced layer portion, a data processing unit for reconstructing an image of said sliced layer portion on the basis of detected data delivered from said detector, and a display unit for displaying said image on the basis of the results of said reconstruction.
Abstract: Upon applying a discharge voltage between opposed electrodes of a plasma display panel, all electrodes other than a selected electrode are clamped at a fixed potential. To that end, a toggled voltage is supplied from a toggled voltage source and applied via a first switching circuit, to one ends of a plurality of second switching circuits in common. The other ends of the second switching circuits are respectively connected to panel electrodes and to one end of third switching circuits. The other ends of the third switching circuits are respectively held at a fixed potential. The second and third switching circuits may be driven synchronously in such manner that when one is ON, the other is OFF and vice versa when a toggled voltage is not brought to a panel electrode, that panel electrode is clamped at a fixed potential. Such a first switching circuit and a group of second switching circuits are combined into one set.
Abstract: A driving circuit for fluorescent display device capable of displaying letters, figures, symbols or the like in multiple luminous colors with a constant brightness is disclosed. The driving circuit comprises a voltage controlling means for controlling an output voltage in response to inputs to be displayed in the device, a pulse generating means for generating a pulse signal having the peak value which is regulated by the voltage level of the voltage controlling means and having the pulse width which is regulated by the input to be displayed in the device, and a driving means for driving the fluorescent display device in response to the output of the pulse generating means.
Abstract: An X-ray collimator for use in computerized axial tomography apparatus includes a plurality of substantially parallel X-ray absorbing laminae disposed in the plane of a wedge-shaped X-ray beam. The length and position of each lamina with respect to a divergent X-ray source is chosen to maximize the ratio of X-ray flux impinging upon a detector array to flux falling within the collimator's penumbra, outside the detector array.A single set of moveable jaws may be disposed at the collimator exit for adjustment of the beam thickness.
Abstract: Starting and operating circuit for gaseous discharge lamps has device for quickly re-starting extinguished lamps while still hot. Circuit comprises ballast reactor, pulse transformer having a magnetic core formed with an air gap, charging capacitor and voltage sensitive switch device connected to the pulse transformer to form a series discharge loop with a portion of the transformer, and a storage capacitor connected at the output of the ballast reactor having sufficiently high capacitance to provide, in combination with the pulse transformer, for hot re-start of the lamp.
Abstract: A field emission electron gun including a cathode, a control electrode which is disposed in the vicinity of the cathode, an anode which is disposed for accelerating electrons emitted from the cathode, and a source of a D.C. voltage to be applied between the cathode and the anode. Also, there is provided a switching arrangement capable of changing-over a potential of the control electrode between ground potential and a potential of the cathode, and an arrangement capable of varying relative positions of the cathode and the control electrode.
Abstract: A magnetic rotary encoder for detecting the absolute value of an angular displacement using magneto-resistors is disclosed. A drum, disk or cup-shaped rotary member is attachable to a rotatable shaft. A magnetic medium divided into a plurality of tracks is provided on a surface of the rotary member. Each of the tracks produces magnetic fields changing in magnitude and direction as the rotary member revolves. Alternatively, a plurality of permanent magnets are provided on the surface of the rotary member to produce the alternating magnetic field as the rotary member revolves. A plurality of magneto-resistors are provided in the vicinity of the rotating paths of the tracks and produce analog signals indicative of changes in their electrical resistances. A rotary condition detector receives the analog signals and produces digital signals and/or an analog signal indicative of the angular distance moved by the rotatable shaft in an absolute value.
Abstract: A D.C. power supply energized directly from an A.C. source including a voltage doubler circuit supplied with current from the A.C. source via a gate controlled bidirectional switch with the gate circuit for the bidirectional switch connected for control by a disabling switch means. The disabling switch means is controlled by a voltage level sensing circuit that senses the output voltage of the voltage doubler circuit to cause operation of the disabling switch means to disable the gate circuit for the bidirectional switch when a predetermined voltage level is sensed by the sensing circuit.
February 28, 1980
Date of Patent:
June 9, 1981
Minnesota Mining and Manufacturing Company
Abstract: A multi-stable optical device and system which utilizes an active optical element such as a spatial light modulator (SLM) in a feedback path configuration. The elementary system consists of a pair of image element (pixels) on the SLM whose input and outputs are coupled to each other by purely optical means. In another arrangement, multi-stable performance is achieved by optical path geometry defining a single pixel which performs in conjunction with a feedback path. Analysis is provided identifying the equilibrium states of the system as well as those equilibrium states which are stable in nature.
March 28, 1979
Date of Patent:
June 9, 1981
The Ohio State University
Stuart A. Collins, Jr., Uday K. Sengupta, Ulrich H. Gerlach
Abstract: The time of travel of an electromagnetic rapping device plunger is measured between two predetermined points so that the height of lift of the plunger and the terminal velocity can be determined.
Abstract: A compact low loss microwave filter is disclosed which utilizes an angular section of a right circular cylindrical cavity at the resonance structure excited in the circular electric TE.sub.0mn mode. The individual sectors may be electrically or magnetically coupled through common walls to obtain various filter characteristics.
Abstract: In an exemplary embodiment, a charge image resulting from x-ray exposure of a plate originally charged to 1.5 to 5 kV, is developed by applying powder of opposite polarity while applying a voltage of from 1 to 4.5 kV, also of opposite polarity, to a conductive backing for neutralizing the effect of image background charge. A grid is spaced a small distance from the charge image and receives a voltage of about 1000 volts for controlling edge emphasis. For a positive charge image and negatively charged powder, a negative potential of e.g. -2500 volts may be applied to the backing for the photoconductive layer and +1000 volts may be applied to the grid.
Abstract: A gas detecting means of this invention is provided with a discharge section which radiates light by electric discharge, a detecting section which collects an ion current of a sample gas ionized by the light, and an optical path which connects the discharge and the detecting sections. The discharge is formed by a pointed cathode and an anode having a penetration hole. The tip of the pointed cathode is directed to the optical path. The diameter of the penetration hole of the anode is smaller than that of the optical path. The anode is disposed in such a manner that any peripheral part of an inlet of the penetration hole is at an equal distance from the tip of the cathode. Both the discharge section and the detecting section are shielded electrically by an outer shell of metal.
Abstract: A method of apparatus for making X-ray photographs of a jaw structure which makes it possible to obtain clear and distinct images of the dental arch without superimposition of neighboring teeth and further to equalize the enlargement ratio of images to be made on the film no matter which spots of the teeth may be taken at the time of X-ray photographing.