Abstract: A radiographic machine in which the exposure is equalized as between different areas of the image plane so as to enhance high spatial frequency features of the image and suppress low spatial frequency features and achieve other benefits as well. A fan beam which is wide enough to encompass the object being imaged is swept across the object and segments of that beam are individually pulse width modulated at each of a number of sampling intervals during the sweep by monostable or bistable shutter pins which either completely block or completely uncover the sectors which they control. An alternate embodiment adds beam width modulation as well, by making the shutter pins either completely block their sectors of uncover them only to the degree necessary for beam width modulation.

Abstract: A high thermal emittance coating for an x-ray tube anode target which permits broader application parameters and a stable coating. The coating is composed of Al.sub.2 O.sub.3 present in an amount of 50% to 80% by weight and ZrO.sub.2 or La.sub.2 O.sub.3 and TiO.sub.2 present in an amount of 50% to 20% by weight with the TiO.sub.2 and ZrO.sub.2 or La.sub.2 O.sub.3 being present in a ratio in the range of 1:1 to 10:1. A preferable coating is composed of about 80% by weight of Al.sub.2 O.sub.3 and 20% by weight of TiO.sub.2 and ZrO.sub.2.

Abstract: An X-ray analysis crystal is also curved in a direction transverse to the dispersion direction to increase the radiation efficiency. As a result of this radiation diffracted at the crystal is focused towards a detector input. In order to ensure a non-deformable crystal surface the crystal is preferably bonded to a carrier having an adapted bonding profile.

Abstract: A dental X-ray irradiation indicating device which permits accurate indication of a location to be X-rayed and also permits photographing of an image substantially with the exact size. The device comprises a supporting member, an arm means extending from the supporting member, and an indicating member mounted on the arm means by way of a mounting member, whereby the indicating member is positioned in an opposing relationship to an intra-oral X-ray film package which is held in a predetermined angular position in an oral cavity of a patient. When an intra-oral X-ray photograph is to be taken, an X-ray is irradiated with reference to the indicating member of the device.

Abstract: Detectors (20) of a CT scanner (10) have a radiation receiving face (34) which is larger than a photosensitive face (30) of a photodiode (22). Lead wires (28) connect the ends of the diode photosensitive surface to terminals (26). A scintillation crystal (32) has an overhanging portion (38) which overhangs at least the interconnection between the lead wires and the photosensitive face to protect the adjoining areas of the photosensitive face from incident radiation. This enables the radiation receiving surface to be larger than the photosensitive surface. The crystal is either undercut to define the overhanging area or a section of light pipe (60) is provided between the photosensitive surface and the crystal. Increasing the radiation receiving face decreases rotor ripple artifacts. Decreasing the photosensitive face area decreases diode capacitance and increases resistance which improves amplifier performance.

Abstract: A raster scan x-ray bone densitometer. The densitometer shown uses an x-ray tube operated at two different voltages to generate a pencil beam, the energy levels of the x-ray photons being a function of the voltage applied. An integrating detector is timed to integrate the detected signal of the patient-attenuated beam over each pulse, the signals are converted to digital values and a digital computer converts the set of values produced by the raster scan into a representation of the bone density of the patient. Multiple reference detectors with differing absorbers are used by the system to continuously correct for variation in voltage and current of the x-ray tube. Calibration is accomplished by the digital computer on the basis of known bone-representing substance being carried repeatedly through the pencil beam so that a set of detected signals affected by the calibration substance is compared by the computer with a set of detected signals unaffected by the calibration material.

Abstract: A lithography system is disclosed which is capable of doubling the spatial frequency resolution associated with conventional systems. A spatial filter, positioned to intercept the Fraunhofer diffraction pattern of the mask being exposed, is configured to prevent certain orders of the diffraction pattern (in most causes the O-order and .+-.2nd, 3rd, . . . orders) from reaching the wafer's surface. The remaining orders reaching the wafer surface (in most cases the .+-. first-order beams) will produce a cos-type interference pattern with a period half of that if the mask grating were imaged without spatial filtering. Therefore, for a system with a given magnification factor m, a mask grating with a period p will be exposed on the wafer surface as a grating with a period of p'=pm/2. Advantageously, the spatial filtering technique of the present invention allows for a variety of different structures (conventional gratings, chirped and phase-shifted gratings, grids, Fresnel zone plates, etc.

Abstract: An apparatus for producing high energy, pulsed, flash X-rays which is of a useful laboratory-scale size. The apparatus includes a hydrogen thyratron coupled between a D.C. power source and a low impedance Blumlein, and a low impedance X-ray head. The thyratron is in a grounded grid configuration and provides a commutated input voltage to the Blumlein at a high repetition rate. The switching waveform output of the Blumlein is applied across a pair of spaced electrodes in the X-ray head to produce an X-ray emitting discharge therebetween. A portion of the electrode assembly is preferably cast integral in an insulating base plate of the head. A pair of foil sheet conductors are preferably cast in the base plate to respectively connect the electrodes to the Blumlein. An apertured cover plate is mounted over the base plate with a seal ring interposed between the plates around the electrodes to establish a sealable evacuatable chamber around the discharge gap between the electrodes.

Abstract: A soft X-ray lithographic system for making a reduced copy of a pattern is described. The system contains a source of soft X-rays, a spherical concave reflector which convergently projects the soft X-rays from the emitting means through a pattern to be copied and a Fresnel zone plate which focuses and reduces the beam of soft X-rays convergently projected through the pattern.

Abstract: An x-ray tube includes a cathode which supplies electrons that bombard a target material to produce x-rays. The target is supported on a rotating anode that includes fins covered with a high emissivity material. An envelope surrounds these elements and provides a vacuum chamber in which they operate. A receptor is mounted to the envelope and includes fins which mate with the anode fins to enhance the radiation of heat from the rotating anode. A cooling liquid is pumped through the receptor.

Abstract: Apparatus is described for immobilizing a child and shielding its gonads during X-ray examination. The child is held on the upper surface of an X-ray transparent horizontal platform with its legs straddling a vertical post bearing a laterally extending lead shield. The lead shield is both vertically and horizontally positionable so as to permit precise and close spacing above the child's body. The lower surface of the child supporting platform is flanged to provide a frame which retains an X-ray film cassette and minimizes blurring resulting from the child's movement. A gonadal shield assembly which is suitable for both male and female children has a generally triangular sheet of lead mounted on a rotatable X-ray transparent plate which is supported by an X-ray transparent arm extending laterally from the post.

Abstract: An x-ray diagnostics installation having an image intensifier video chain which back-projects a region of primary medical interest within an x-ray image into the overall video image is provided with fiber optics and opto-electronic transducers which are actuated by a switching bank in accordance with the desired shape and position of the region of primary interest. The transducers and switching arrangment can be removed, so that the output image from the x-ray image intensifier can be viewed at the output side of the fiber optics.

Abstract: A contoured X-ray imaging system consists of an X-ray source and X-ray film holding cassette for taking X-ray pictures closely adjacent to a body surface without unnecessary exposure of adjacent body parts to X-rays. The X-ray cassette is contoured to the outline of a structure or a body part to evaluate it without the radiation spreading unnecessarily to the adjacent areas. The X-ray cassette is a thin flat box which has an edge wall contoured outline of the subject or an adjacent structure. The X-ray source and intervening shields or the like are each configured to project an X-ray beam which is contoured in the same contour as the film-holding cassette so that the X-rays reach the film in the same contour as avoid unnecessary exposure of adjacent portions of the body to the X-rays.

Abstract: In an X-ray scanner, the driving motor (10) for the X-ray source (4) with the detector (5) is in the form of a linear motor, which is preferably provided with two magnet poles (15), between which a metal disk (9) is moveable. The metal disk is connected to a supporting ring (7) for the source and the detector.

Abstract: In a diagnostic process in which two images are made on an image recording medium of the same structure at the beginning and the end of a time interval during which the structure changes, a method is provided for permitting a computing device to improve the alignment of the images as reproduced in the form of pixels on a monitor screen. A particular spatial pattern of marker elements is provided, when each of the images is made, in a particular juxtaposition to the structure being imaged, so that the shadows of the elements arise on the respective images. The computing device can then rotate, translate and alter the scale of one image with respect to the other until the shadows of the elements on one image coincide as closely as possible with those on the other image.

Abstract: A light distributor for directing the light of the output image of an x-ray image intensifier to a number of different types of cameras in an x-ray diagnostics installation has a housing to which the cameras are attached with their respective beam path axes disposed perpendicularly relative to each other and perpendicularly relative to the axis of the beam path from the x-ray image intensifier. A first mirror deflects the beam from the x-ray image intensifier to one of the cameras, and a second moveable mirror is introducible into the beam path between the first mirror and the first camera to deflect the beam from the x-ray image intensifier onto a second camera.

Abstract: Spot film apparatus which includes a menu-driven microprocessor for producing control signals to position a film cassette as required to carry out operations in a manner shown on a display. The spot film apparatus includes an improved carriage assembly which comprises a pair of opposing holding arms which conform with the film cassette. The opposing holding arms are biased towards each other with a helical spring. Loading of a cassette into the arms is accomplished by moving one arm with a continuous chain drive which supports a pawl-like member projecting therefrom, while maintaining the position of the second arm.

Abstract: A method is disclosed for producing a X-ray image by a photoconductor which converts X-rays into a charge pattern and which is uniformly charged prior to the X-ray exposure and is discharged during the X-ray exposure as a function of the intensity of the X-rays, the surface of the photoconductor being scanned to measure the charge density, for each pixel point there being formed an image value which is dependent on the discharge at the relevant pixel whereby dot-shaped artefacts in the X-ray image may appear.

Abstract: A gating and target device for an x-ray examination apparatus has a secondary radiation diaphragm and an x-ray film cassette, the secondary radiation diaphragm having two diaphragm plates disposed in parallel planes, and moveable relative to each other so that the diaphragm plates can be adjusted to at least partially overlap. Each of the diaphragm plates has a diaphragm opening therein, with the remainder of the plate being impermeable to x-radiation, so that by adjusting the relative positions of the plates, an opening of selected size may be formed by either one of said diaphragm plates at least partially covering the opening of the other diaphragm plate. To minimize the thickness of the device, and thus to minimize the distance between the target x-ray film and an examination subject, one of the diaphragm plates has a scattered ray grid structurally integrated within the opening of that plate.

Abstract: In a system for exposing X-ray film to X-rays, to adequate density, X-rays emitted from a X-ray tube and passing through an object are incident on a X-ray film through a X-ray pickup device. A X-ray pickup device having a plurality of pickup fields comprises an intensifying screen for converting X-rays into light rays. In each of the pickup fields, a bundle of optical fibers are extended and end faces of the fibers are so arranged as to occupy each of the pickup field with segment pickup field of the optical fibers. The optical fiber bundles are optically coupled to photodetectors, respectively so that light rays are converted into electrical signals.