Abstract: The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Abstract: At least one primary diaphragm comprises two elements displaceable so as to form a linear fan-shaped beam which is incident on an object to be examined. The elements form the slit-shaped aperture forming the fan beam in their normal X-ray beam forming position and are moveable to a respective, selectable limit position perpendicularly to the fan shaped beam in order to define and mark an examination zone greater in cross-section area than the fan beam with a light beam. Light incident on the examination zone is restricted by the diaphragm elements in their limit positions, thus marking the examination zone with the light beam. X-ray exposure of the object to be examined takes place only when the elements are between the two positions defining the examination zone of the primary diaphragm where its diaphragm elements occupy in their respective limit positions.

Abstract: An improved metal center rotating anode x-ray tube is shown. The improved x-ray tube includes means for preventing the build-up of charge on the anode glass portion of the tube envelope where the glass flares by constraining the equipotential lines of the electric field in the vicinity of th eflare to parallel the flare surface. Parallelism may be achieved by (1) controlling the angle of the flare and sealing the flare directly to the metal section, (2) modifying the anode rotor to include a flare conforming to the glass flare, and (3) including a ground plane screen in the tube housing.

Abstract: An inner focusing type telephoto zoom lens includes a fixed first lens group having a positive refractive power, the first lens group being disposed closest to the object, a second lens group having a negative refractive power, the second lens group being movable along an optical axis for focusing, a fixed third lens group having a positive refractive power, a fourth lens group having a negative refractive power, the fourth lens group being movable along the optical axis for zooming, a fifth lens group having a positive refractive power, the fifth lens group being movable along the optical axis relative to the fourth lens group, and a fixed sixth lens group having a positive refractive power. The zoom lens satisfies the following condition:0.4<.vertline.f.sub.2 .vertline./f.sub.123 <0.9where f.sub.123 is a composite focal length of the first, second and third lens groups, and f.sub.2 indicates a focal length of the second lens group.

Abstract: An optical communication link coupling a rotating part of a gantry of a computerized tomographic scanner to the stationary part of the gantry. The link comprises an arcuate hollow light conductor having one part rotating with the rotor of the gantry and the other part fixed to the stator of the gantry. Signal bearing light beams are transmitted into the link and are subsequently received from the link after transversing at least a portion theroef.

Abstract: An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

Abstract: A measurement-while-drilling (MWD) density tool is provided which incorporates a single gamma ray source and a pair of longitudinally displaced and mutually aligned detector assemblies (i.e., dual scintillation counters). A nuclear source is mounted in a pocket in the sub wall and partially surrounded by gamma ray shielding. The subwall section adjacent the source is expanded radially so as to define a lobe which displaces mud thus reducing borehole and mudcake effects. The two detector assemblies are mounted within a cavity or hatch formed in the subwall and enclosed by a detector hatch cover under ambient pressure. The detector assemblies are fixedly spaced from the source and are also partially surrounded by gamma ray shielding to provide good formation response. The hatch cover is secured to the sub by bolts and contains radiation transparent windows therethrough in alignment with the detector assemblies. A threaded-on fluid displacement sleeve is positioned on the sub and over the detector hatch cover.

Abstract: A projection lens system having a first positive lens group which includes a positive lens having a strongly convex surface facing the enlarged side and a negative lens, a seond negative lens group which includes a positive lens and a lens in the form of a negative meniscus lens having a concave surface facing the enlarged side, a third lens group which includes a lens in the form of a meniscus lens, wherein at least one lens surface is aspherical, having a concave surface facing the enlarged side, and a diaphragm is arranged between the first positive lens group and the second negative lens group, and wherein said projection lens system is standardized by the conditional expression to form compactly.

Abstract: A method for sorting a plurality of diverse objects into groups, each such object being made predominately from at least polyethylene terephthalate and polystyrene and at least two of polyvinyl chloride, polyethylene and polypropylene, the groups consisting at least of objects of like type of polymer identified to be polyethylene terephthalate and polystyrene and at least two of polyvinyl chloride, polyethylene and polypropylene. The method includes three steps. The first step is to irradiate the objects to be sorted with near-infrared radiation. The second step is to measure the diffuse reflectance of the irradiated objects in the near-infrared region to identify the objects as to the type of polymer used to make them. The third step is to direct the objects to their respective groups according to the measurement and identification of the second step.

Abstract: A linear detector selectively detects successive line images from different angles while the linear detector and a radiation source are rotated about a patient. Radiation-transmission images are generated and detected and converted to computer-grabbed images by a computer which acquires, processes, stores and reconstructs the images. A visual monitor display reconstructs video images including a planar image and tomographic images representing sections orthogonal to the planar image. Selectively-positionable field-delineating lines corresponding to intersectional outlines between a simulation beam and the planar image are overlaid on the planar image. Beam-delineating lines are updated by the computer to correspond to intersectional outlines as the field-delineating lines are positioned.

Abstract: Arrangement for supporting and positioning X-ray cassettes (13) in the required position in radiography of patients confined to bed. The arrangement comprises at least one holder (10) and a lifting means (30). The holder (10) may be of different design, and in one preferred embodiment it comprises a base member (11) and a cassette support (12) extending upwardly therefrom, the base member (11) being supported by the bedstead bottom (15), and the X-ray cassette (13) being fixable standing on edge between the base member (11) and the cassette support (12). The lifting means (30) is adapted to be inserted between the bedstead bottom (15) and the mattress (14) in order to raise the latter, so that the X-ray cassette (13) is insertable in the space thus formed.

Abstract: The invention relates to a motor vehicle headlight glass suitable for being mounted in a position where it slopes relative to a vertical plane, and being of the type that comprises a plurality of stripes for the purpose of spreading the light emitted by the headlight substantially in a lateral direction. Each stripe in at least one given group of stripes has a stripe surface which is ruled and without slope discontinuity, having tangency planes which define a set of unit prisms whose prism angles and whose slopes relative to the vertical vary together in such a manner that an incident ray on any one of the prisms is deflected laterally by the prism by an amount that varies depending on the prism, but without being subjected to vertical deflection. The invention also provides a method of making a mold die for mass producing the glass, and a method of manufacturing the glass by molding.

Abstract: An X-ray imaging system includes an vacuum tube, which is biased by a high voltage power supply connected to the tube by two shielded cables. The cables collectively have a plurality of conductors which are coupled at one end to the high voltage power supply. The other end of each conductor is coupled to a component of the vacuum tube by a separate inductor. During a voltage breakdown of the vacuum tube, the inductors depress electrical current flow between the anode and the cathode of the tube to reduce the erosion of tube components which results from the discharge. This current is in part due to the energy stored in the cable, which is not depressed by conventional current limiting circuits in the high voltage power supply. Voltage limiting devices connected to the tube prevent ringing in the cables from generating excessively high voltage levels.

Abstract: Transmission images are obtained by radiating X-rays having two different energy levels onto a subject in one direction, and then transformed into logarithmic images, respectively. From these logarithmic images, a contrast ratio due to the two kinds of X-rays having different energies is obtained. From this contrast ratio, the term relating to the thickness of the subject is eliminated, thereby providing information only relating to the quality of the material. By collating the information with the previously measured data of materials, the material of the subject is identified.

Abstract: A direction sensitive energy detecting apparatus characterized by having a pair of energy receiving and transmitting devices of different polar characteristics and so disposed that they define together one end of a path in such a way as to be coincident with each other; with the sensor being adapted to give two first outputs at least one of which is variable as a function of the direction of the path and the detector having ratiometric means for generating a second output which is a function of the ratio of the two first outputs and is variable only in response to changes in direction.

Abstract: The invention relates to a circuit array for an optical Schmitt trigger in which an optical input signal is converted into an electrical output signal by means of a light-sensitive receiver element, an amplifier stage, a Schmitt trigger stage and an output stage.It is provided in accordance with the invention that the amplifier stage contains a transimpedance amplifier stage, a differential amplifier stage, a first reference network and a compensating element, that the Schmitt trigger stage comprises a differential amplifier stage, a second reference network and a positive-feedback network, and that the output signal is emitted at the circuit output of the output stage.

Abstract: An imaging X-ray microscope having an X-ray radiation source, a condenser for condensing X-rays radiated from the X-ray source on an object, an objective for forming an image of the object by the X-rays transmitted through or diffracted by the object, and an X-ray detector for receiving the image formed by the objective, the objective comprising a Schwarzschild optical system in which a concave mirror with an opening in the center thereof and a convex mirror are coaxially arranged in such a manner that the convex mirror opposes to the opening of the concave mirror, the object-side numerical aperture is at least 0.24, and the following condition is satisfied:(N.A.-0.6)/12.ltoreq.(W.sub.2 -W.sub.1)/f.ltoreq.-0.005where N.A. is the object-side numerical aperture of the Schwarzschild optical system, W.sub.1 is the distance from the object to the center of curvature of the concave mirror, W.sub.

Abstract: A heterojunction optical switch is taught. Briefly stated, birefringence in the form of a Pockel Cell is utilized such that biasing of the Pockel Cell permits the passage of light therethrough. Preferably, a light detector and resistor are electrically in parallel with the Pockel Cell such that light impinging upon the light detector causes the Pockel Cell to be reverse biased with the result that a separate light source may pass through the Pockel Cell. In this fashion, the Pockel Cell operates as a true optical switch.

Abstract: Disclosed is a plate with lens array comprising a transparent plate, and a plurality of gradient index lenses, at least two of which have different focal lengths, the lenses being linearly or two-dimensionally arranged in the transparent plate.

Abstract: The radiation image of a subject such as a human spine is recorded on and read from a stimulable phosphor sheet which is circulated in a radiation image recording and reading apparatus. The stimulable phosphor sheet with the radiation image recorded thereon is fed to an image reading unit in which stimulating light is applied to the stimulable phosphor sheet to cause the stimulable phosphor sheet to emit light representative of the recorded radiation image. Then, the stimulable phosphor sheet is fed to and past an erasing unit, which applies erasing light to the stimulable phosphor sheet to erase any residual radiation image information from the stimulable phosphor sheet in the erasing unit, while feeding the stimulable phosphor sheet back past the erasing unit. The stimulable phosphor sheet is held in readiness for recording another radiation image thereon after the residual image information has been erased, and thereafter, the stimulable phosphor sheet is fed to an image recording unit.