Abstract: After gain correction acquisition images are collected, an image reading apparatus calculates any deviation between the grid direction and the pixel line-up direction of a solid-state imaging element (12) in the rotation direction in the grid direction calculation process, and the deviation of a grid (11) in the rotation direction is corrected by accurately aligning the grid direction in the gain correction acquisition image to have a given relationship with respect to the pixel line-up direction, thus photographing an image in practice.

Abstract: An X-ray image pickup device has a two-dimensional image reading device which is constituted by two-dimensionally forming a plurality of photoelectric conversion elements on an insulating substrate, and has switching elements in the vicinities of these photoelectric conversion elements, a phosphor which is formed on the two-dimensional image reading device and serves as a wavelength converter for converting X-ray radiation into visible light, and a grid plate which is formed on the phosphor and guides only X-rays from a specific direction toward the phosphor and the two-dimensional image reading device, whereby a next-generation X-ray image pickup device which can improve diagnostic efficiency that cannot be attained by the conventional film method, and has a high space factor and a high S/N ratio that cannot be attained by the CCD method can be provided.

Abstract: An apparatus for radiological examination is provided with the grid 16 that is driven in reciprocating motion in order to reduce the effect of radiation scattered by the body of the patient being irradiated. The grid 16 is connected to a counterweight 23, and is moved through a motion transmission mechanism that is of the crank and connecting-rod type so as to ensure a dynamic balancing of the oscillating masses. With this simple and accurate type of driving system, better quality radiographic images can be obtained under different adjustment and set-up conditions of the apparatus.

Abstract: Air cross grids, for absorbing scattered secondary radiation and improving radiation imaging in general radiography and in mammography, are provided with a large plurality of open air passages extending through each grid panel. These passages are defined by two large pluralities of substantially parallel partition walls, respectively extending transverse to each other. Each grid panel is made by laminating a plurality of thin metal foil sheets photo-etched to create through openings defined by partition segments. The etched sheets are aligned and bonded to form the laminated grid panel, which is moved edgewise during the radiation exposure to pass primary radiation through the air passages while absorbing scattered secondary radiation arriving along slanted paths.

Abstract: In an x-ray imaging system, an x-ray detector assembly includes an x-ray detector and a support assembly secured to the x-ray detector for supporting an antiscatter grid assembly. The x-ray detector preferably includes a matrix of crystal detectors. The support assembly includes a foam bezel having one or more magnets disposed therein. The antiscatter grid assembly includes an antiscatter grid secured to a metal frame. The one or more magnets disposed in the bezel are situated so as to align with the metal frame of the antiscatter grid assembly when the antiscatter grid assembly is coupled to the x-ray detector assembly. The strengths of the one or more magnets are such as to allow the antiscatter grid assembly to be removably secured to the x-ray detector assembly. Alternatively, the one or more magnets may be secured to the metal frame of the antiscatter grid assembly and corresponding metal plates may be placed in the support assembly.

Abstract: A radiographic grid with reduced line density artifacts. The radiographic grid includes a grid housing sized to receive a plurality of x-ray radiation absorbing lamellae. Each of the plurality of lamellae has a foil strip applied to its lower end portion. The foil eliminates the lamella line artifacts otherwise emanating from the lamellae.

Abstract: A stray radiation grid for penetrating radiation is produced by starting with a carrier material and producing holes in a first surface thereof, and subsequently filling the holes with penetrating radiation absorbing material. A second, opposite surface of the carrier block is etched away to reduce the thickness of the carrier block, leaving a carrier which is flexible and bendable, from which the radiation absorbing material projects as a number of free-standing absorption elements.

Abstract: A stray radiation grid, particularly for a medical X-ray apparatus, is composed of a carrier material with absorption elements, particularly in the form of lead lamellae, that are arranged in rows spaced from one another and proceeding essentially parallel to one another, with the respective spacings between the successive rows of absorption elements being larger in the region of the edges of the grid than in the middle region.

Abstract: An X-ray collimator grid is formed within a wafer of monocrystalline silicon material by forming a plurality of spaced parallel elongate slots within a planar surface of a silicon crystal wafer, and forming slats of heavy metal in situs within each of said slots, including squeegeeing the heavy metal into the slots, from particles of heavy metal, each said slat gripping the walls of an associated slot.

Abstract: An integrated radiation detecting and collimating assembly for an x-ray tomography scanning system. The assembly includes a housing which mounts to a spine of the system and aligns corresponding arrays of photodiodes, scintillator crystals and anti-scatter plates with one another and with x-ray beams arriving directly at the detectors from the focal spot. The arrays of photodiodes, crystals and anti-scatter plates are thus all fixed relative to one another within the housing, which is itself securely fixed to the frame of the scanner system.

Abstract: The present invention resides in a Fourier filter to detect defects on semiconductor wafers. The present invention relates to a Fourier filter to detect defects on semiconductor wafers which is less susceptible to having the filter output affected by vibrations and which avoids the physical contact from conventional damping.

Abstract: Methods for making large area grids consisting of focused and unfocused holes in sheets of metal. The grid consists of thin metal walls surrounding hollow openings. The projection of all walls converge to a focal spot in the focused grid, and on parallel or substantially parallel in an unfocused grid. A grid having a large area is made by interlocking together smaller grid pieces. A tall device is made by stacking layers of focused grids. Methods to make unfocused grids that detect parallel incoming x-rays are also described. The opening of the grid can be filled with phosphor or other scintillating materials to make a integrated grid/scintillator structure. These grids can also be applied to many applications such as x-ray antiscatter for diagnostic medical imaging, non-destructive testing, x-ray collimation, filters for liquids or electromagnetic radiation.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Abstract: A receptacle (3, 13) for an anti-scatter grid (4) and the anti-scatter grid (4) of a catapult grid drawer (1) are constructed such that the anti-scatter grid (4) is held in the receptacle (3, 13) only in a predetermined orientation. In accordance with one variant, guides (5, 6) of the receptacle (3) cooperate with edges (7, 8, 9, 10, 11, 12) of the anti-scatter grid (4) so that together they form a key and slot connection. In accordance with a further variant of the invention, e.g. the anti-scatter grid (4) is provided with a machine-readable code (14). A reader (15) for the code (14) as well as a lock (19) controlled by a signal from the reader (15) are provided in the region of the receptacle (13). The lock (19) releases the access to the receptacle (13) only if the predetermined orientation between the grid (4) and the receptacle (13) exists.

Abstract: A method of nondestructive investigation of the internal structure of an object uses deflected penetrating radiation. In one embodiment, an incident penetrating radiation flow 4 with angular divergence restricted by a collimator 3 passes through an object 5 to create the a radiation flow 6 registered by a direction-selective detector 10. Typically, the directivity pattern of detector 10 selects a desired angle and has a width no larger than twice the local angular divergence of the incident penetrating radiation flow 4. The desired angle can be the maxima of a scattering pattern for a substance suspected of being in object 5. To improve the quality and range of measurements, the local restrictions of radiation flow 4 is fulfilled in the two intersecting planes; and detector 10 and/or incident radiation flow 4 can be swept through a range of orientations to detect radiation deflected at a range of angles larger than the directivity pattern detector 10 has when fixed.

Abstract: Air cross grids, for absorbing scattered secondary radiation and improving X-ray imaging in general radiography and in mammography, are provided with a large plurality of open air passages extending through each grid panel. These passages are defined by two large pluralities of substantially parallel partition walls, respectively extending transverse to each other. Each grid panel is made by laminating a plurality of thin metal foil sheets photo-etched to create through openings defined by partition segments. The etched sheets are aligned and bonded to form the laminated grid panel, which is moved edgewise during the X-ray exposure to pass primary radiation through the air passages while absorbing scattered secondary radiation arriving along slanted paths.

Abstract: A radiographic grid with reduced line density artifacts. The radiographic grid includes a grid housing sized to receive a plurality of x-ray radiation absorbing lamellae. Each of the plurality of lamellae has a foil strip applied to its outer walls. The foil eliminates the lamella line artifacts otherwise emanating from the lamellae.

Abstract: An imaging system spatially modulates penetrating radiation that passes through an object under investigation. The modulation introduces spatial irregularities which can be deflected while passing through the object under investigation. The deflection of each irregularity can be identified and is converted into contrast of in a projection of the object. One embodiment of the invention includes: a source of penetrating radiation 1, and a modulator 3 for the creation of spatial irregularities; and a detector 5 for measuring transverse translations of spatial irregularities and converting the measured transverse translations into contrast in a projection 8 of object 4.

Abstract: In a CT scanning system having an x-ray source, a plurality of x-ray detector modules, and a plurality of anti-scatter plate modules, signal instability and the associated introduction of artifacts into the reconstructed images are prevented by an alignment assembly which permits the anti-scatter plates to be substantially aligned with regions of substantially constant maximum sensitivity of corresponding detectors. Shadows cast by the anti-scatter plates fall entirely within these regions of substantially constant maximum sensitivity to radiation, thereby minimizing signal modulation due to thermal effects or relative movement of the source, the detectors and the anti-scatter plates between scans.

Abstract: It is an object of the invention to provide an X-ray diagnosis apparatus having an X-ray plane detector capable of removing the influence of a scattered X-ray by using a grid and also preventing a Moire image. An X-ray image transmitted through a target object is sensed by a plane detector in units of pixels which are two-dimensionally arranged at a predetermined pitch. A scattered X-ray incident on the plane detector is removed by a scattered ray removing grid having plate-like X-ray shielding members and arranged on an X-ray incident side of the plane detector. The X-ray shielding members are arranged such that an X-ray shielding pattern on the X-ray incident surface of the plane detector has a pitch corresponding to an integer fraction of the arrangement pitch of the pixels. When a steady positional relationship is kept between the pitch of the X-ray detection elements and the period of the fringe pattern of the X-ray which is shielded by the grid, a Moire image can be prevented.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Abstract: Air cross grids, for absorbing scattered secondary radiation and improving X-ray imaging in general radiography and in mammography, are provided with a large plurality of open air passages extending through each grid panel. These passages are defined by two large pluralities of substantially parallel partition walls, respectively extending transverse to each other. Each grid panel is made by laminating a plurality of thin metal foil sheets photo-etched to create through openings defined by partition segments. The etched sheets are aligned and bonded to form the laminated grid panel, which is moved edgewise during the X-ray exposure to pass primary radiation through the air passages while absorbing scattered secondary radiation arriving along slanted paths.

Abstract: An anti-scatter x-ray grid for medical diagnostic radiography includes a substrate having channels therein of material that is substantially non-absorbent of x-radiation and absorbing material in the channels including material that is substantially absorbent of x-radiation. The substrate preferably comprises material capable of remaining stable at the melting temperature of the absorbing material.

Abstract: In an x-ray diagnostics apparatus having a scattered radiation grid moveable in a plane, the movement of the scattered radiation grid ensues via a tumbling or wobble bearing arranged between a rotating drive and the scattered radiation grid. An advantage of this arrangement is that relatively long standstill times during the reversal of the grid movement are reduced. Moreover, the tumbling or wobble bearing can be economically manufactured and is less structurally complicated than a lever articulation.

Abstract: A method for fabricating an anti-scatter x-ray grid for medical diagnostic radiography includes providing a substrate having channels therein and material that is substantially non-absorbent of x-radiation; and filling the channels with absorbing material that is substantially absorbent of x-radiation. In one embodiment, the step of providing a substrate having channels therein comprises sawing a plastic substrate with a thin circular blade and the step of filling the channels with absorbing material comprises melting the absorbing material and flowing the melted absorbing material into the channels.

Abstract: The invention provides a polarizing device and a method for producing and utilizing the device. The device produces a modification in radiation flux and provides a bias toward photons approaching a target's face at more or less right angles. Accordingly, the radiation flux polarizing device reduces the number of photons that are not traveling at near right angle to the face of a "target" being irradiated, without significantly reducing photons approaching, or reaching the minimum base point in the target. In a sense, the invention converts a normal isotropic radiation source to one that is anisotropic.

Abstract: A collimator assembly for removing selected radiation output from a specimen. The assembly includes collimator elements with each element having walls comprised of a first material covered by an inner layer of a second material which preferentially absorbs inelastic scattered radiation created in the first material.

Abstract: The invention is directed to a grid used in x-ray imaging applications to block scattered radiation while allowing the desired imaging radiation to pass through, and to process for making the grid. The grid is composed of glass containing lead oxide, and eliminates the spacer material used in prior known grids, and is therefore, an air-core grid. The glass is arranged in a pattern so that a large fraction of the area is open allowing the imaging radiation to pass through. A small pore size is used and the grid has a thickness chosen to provide high scatter rejection. For example, the grid may be produced with a 200 .mu.m pore size, 80% open area, and 4 mm thickness.

Abstract: An x-ray anti-scatter grid for x-ray imaging, particularly for screening mammography, and method for fabricating same, x-rays incident along a direct path pass through a grid composed of a plurality of parallel or crossed openings, microchannels, grooves, or slots etched in a substrate, such as silicon, having the walls of the microchannels or slots coated with a high opacity material, such as gold, while x-rays incident at angels with respect to the slots of the grid, arising from scatter, are blocked. The thickness of the substrate is dependent on the specific application of the grid, whereby a substrate of the grid for mammography would be thinner than one for chest radiology. Instead of coating the walls of the slots, such could be filed with an appropriate liquid, such as mercury.

Abstract: A scanning radiographic system having reduced scatter and improved tube loading employs a pre-patient slit to form the x-ray beam into a fan beam and a post-patient slot to eliminate scattered rays from the fan beam. A grid incorporated into the slot permits a further reduction of scatter sufficient to employ a wider slot without detrimental increase in scatter but with significant improvement in tube loading. The lamellae of the grid proceed diagonally across the width of the slot to reduce grid lines and are tipped to focus on the focal spot of the x-ray source.

Abstract: A grid for use in a collimator system for high energy waves such as X-rays and gamma rays includes a silicon base in which slits are etched along multiple separated lines. Located transversely in the slits are tungsten slats. Between the separated lines, silicon is removed by etching. Pairs of grids are longitudinally spaced apart along a longitudinal axis running transversely to the direction of the lines and the slats. Rotating the pair of grids about the longitudinal axis, and providing a detector associated with each grid pair provides for metering high energy rays.

Abstract: An imaging system includes a linear detector array which measures x-rays passing through a patient from an x-ray source. A mask disposed over the detector array has staggered segments that block x-rays and divide the detector array into a pair of slice planes. Signals from the detector elements receiving x-rays in respective ones of the two slice planes are used to separately reconstruct a slice image for each of the two slice planes.

Abstract: An alignment method and system for aligning an anti-scatter grid with an x-ray source of a radiographic apparatus, to facilitate accurate alignment of the central x-ray beam of the x-ray source of the radiographic apparatus with a focused grid. The present invention uses a first light projector that is substantially fixed relative to the x-ray source, which produces a first alignment image that is substantially fixed relative to the grid. Also included is a second light projector that is substantially fixed relative to the grid, and that produces a second alignment image that is substantially fixed relative to the x-ray source. The first light projector is preferably the collimator light included within the collimator housing of the x-ray apparatus, and the second light projector is preferably a laser light source, that is attachable to a grid cassette holding the grid.

Abstract: A radiographic imaging system is comprised of a radiation source 12, a radiation adsorbing grid assembly 18, an image producing element 22 a controller 34, an exposure sequence start means 28 and a grid assembly oscillation means 20. The radiation source and grid define a subject receiving gap, wherein an object under examination is disposed, and through which the source propagates a beam of radiation onto the face of the image producing element. The controller recognizes when the exposure sequence start means is activated and starts the exposure sequence. The exposure sequence is comprised of an exposure preparation interval and an exposure interval. The exposure preparation interval is comprised of a radiation source preparation time and a point-in-time when the grid assembly oscillation commences oscillating the grid assembly.

Abstract: A radiographic grid includes a grid housing having first and second side walls, a first cover sheet disposed on the grid housing, and a plurality of x-ray radiation absorbing lamellae disposed between the first and second side walls of the grid housing. Each of the plurality of lamellae has at least one alignment tab protruding from a lateral edge thereof for engaging the cover sheet such that each of the lamellae are maintained in alignment with respect to each other.

Abstract: A X-ray imaging system has a moveable grid which rejects X-rays that were scattered by a body being imaged. During an X-ray exposure the grid is reciprocated to blur the shadow of the grid in the image. Upon commencement of an X-ray exposure, the grid is moved at decreasing rate in a first direction toward an end point of travel. When the grid is near the end point, the movement rate increases and continues at this faster rate before and after the grid reverses direction at the end point. A given distance after the direction reversal, the rate decreases to a slow constant rate.

Abstract: An improved bucky drive utilizes a reversible rotary motor which drives a screw received in a nut fixed to a bucky grid. A integrated control circuit board for the motor insures that the motor is quickly operated. In other features, the motor is a DC motor with a position sensor. A transistor speed control is utilized. The bucky system may be operated in either a semi-automatic or an automatic mode. The speed of the grid may be controlled. Further, other operational parameters of the system may also be controlled.

Abstract: A collimator for use in an imaging system with a radiation point source has a plurality of channels formed therein along longitudinal axes aligned with selected orientation angles that correspond to the direct beam path from the radiation source to the radiation detectors. The collimator comprises a photosensitive material coated with a radiation absorbent material. The cross-sectional shape of the channels corresponds to the cross-sectional shape of the radiation detecting area of the detector element adjoining the channel, and the sidewalls of the channel are smooth along their length.

Abstract: A collimator for use in an imaging system with a radiation point source is formed from a plurality of collimator plates stacked together. Passages in each collimator plate in conjunction with the respective passages in adjoining plates form a plurality of channels through the collimator. The channel longitudinal axes are aligned with selected orientation angles that correspond to the direct beam path from the radiation source to the radiation detectors. The collimator plates are made up of patterned sheets of radiation absorbent material or alternatively comprise patterned photosensitive material substrates coated with a radiation absorbent material. The cross-sectional shape of each channel corresponds to the cross-sectional shape of the radiation detecting area of the detector element adjoining the channel.

Abstract: A flexible elongated slatted grid structure is suspended between a pair of spaced apart grid support frames each of which is adapted for rotation about a transverse axis intermediate the suspended ends of the grid. Mechanical adjustment means provides equal but opposite angular motion of the frames to curve the grid along a circular path.

Abstract: A method of producing a high angular resolution collimator implemented in an inspection system for detecting the presence of selected crystalline materials, such as explosives or drugs. The system includes an x-ray source and an array of energy dispersive detectors to sense radiation scattered by the objects being inspected. The collimator includes a bundle of optical fibers bonded together to form a stack of plates having a plurality of microcapillaries therein to pass an x-ray beam therethrough. The method includes the steps of stacking the plates, aligning the plates in registration, and etching an inner core without disrupting registration.

Abstract: An X-ray imaging assembly is disclosed comprised of (I) a front and back pair of intensifying screens, (II) a radiographic element mounted between the intensifying screens, and (III) a collimating grid The front screen being chosen to exhibit modulation transfer factors greater than those of reference curve A in FIG. 2 . The radiographic element is comprised of a transparent film support, a front silver halide emulsion layer unit coated on the support and located adjacent the front intensifying screen, a back silver halide emulsion layer unit coated on the support and located adjacent the back intensifying screen, and means for reducing crossover to less than 10 percent. The X-ray collimating grid, located to receive X-radiation prior to the front screen, is comprised of an X-ray opaque material forming an array of at least 85 X-ray transmission apertures per inch providing at least 50 percent open area.

Abstract: An optical alignment system for aligning a film cassette carrying grid cassette with an x-ray source of a portable x-ray apparatus. To facilitate accurate alignment of the central x-ray beam of the x-ray source of a portable x-ray apparatus with a focused grid in a clinical setting, the present invention uses a light projector and a reflector device. The light projector is substantially fixed relative to the x-ray source and projects a spot or line of light on the surface of the grid cassette. The reflector device, which can be temporarily or permanently fixed to the grid cassette, includes a reflector surface and an image surface. Images of the incident light spot or line and of the reflected light spot or line are formed on the image surface, and the distance between the images indicates the magnitude of angulation alignment error between the grid cassette and the x-ray source.

Abstract: A collimator assembly for removing selected radiation output from a specimen. The assembly includes collimator elements with each element having walls comprised of a first material covered by an inner layer of a second material which preferentially absorbs inelastic scattered radiation created in the first material.

Abstract: A collimator for use in an imaging system with a radiation point source has a plurality of channels formed therein along longitudinal axes aligned with selected orientation angles that correspond to the direct beam path from the radiation source to the radiation detectors. The collimator comprises a photosensitive material coated with a radiation absorbent material. The cross-sectional shape of the channels corresponds to the cross-sectional shape of the radiation detecting area of the detector element adjoining the channel, and the sidewalls of the channel are smooth along their length.

Abstract: A collimator for use in an imaging system with a radiation point source is formed from a plurality of collimator plates stacked together. Passages in each collimator plate in conjunction with the respective passages in adjoining plates form a plurality of channels through the collimator. The channel longitudinal axes are aligned with selected orientation angles that correspond to the direct beam path from the radiation source to the radiation detectors. The collimator plates are made up of patterned sheets of radiation absorbent material or alternatively comprise patterned photosensitive material substrates coated with a radiation absorbent material. The cross-sectional shape of each channel corresponds to the cross-sectional shape of the radiation detecting area of the detector element adjoining the channel.

Abstract: A method and apparatus for radiographic techniques using an x-ray source (13). The radiographed object (M) is subjected to a beam (X) of radiation which is employed for forming a radiographic image of the object (M) onto a film (25). Between the radiographed object (M) and the film (25) is utilized a grid assembly (20) that prevents the disturbing effect of backscattered radiation or secondary radiation generated in the radiographed object on the radiographed image. The grid assembly (20) comprises a grid plate (22) having several equidistantly spaced lamellas opaque to x-rays. The x-rays can pass in the direction of the beam axis between the spaces (24) of said lamellas to the film (25). The grid plate is reciprocatingly oscillated at a varying amplitude so that the stops and changes of travel direction (K.sub.1 . . . K.sub.

Abstract: In a radiological apparatus using an antiscatter grid, this grid is kept fixed instead of being movable, and its image is removed by irradiating it as well as the object to be examined by two X-ray sources that have to be separated by a distance b determined by the first zero of the modulation transfer function of this two-source system. To take account of the magnification G, the distance b can be adjusted by means of a cathode emitting two electron beams with adjustable deflection.

Abstract: The quality of image of an object hidden inside a highly scattering semi-opaque disordered medium is improved by using space gate imaging or time gate imaging or space time gate imaging. In space gate imaging, a small segment of the object is illuminated at a time. The scattered light is passed through a spatial noise filter. On the image plane, an aperture is open at the position of the image segment which correspond to the segment of the illuminated object. A full image is obtained by scanning the object segment by segment and simultaneously recording the signal at the corresponding image segment. In time gate imaging, the unscattered (i.e. ballistic) portion of the pulse which contains the information of the image is temporally separated from the other (i.e. scattered) portions which contains the noise using a ultrafast laser pulse and temporal gating devices. The technique is in space-time gate imaging, the two techniques are combined to produce an image with a much higher signal to noise ratio.

Abstract: Scanning slit radiography apparatus with a radiographic grid of the invention makes possible the X-ray imaging at an enhanced primary radiation transmission, yet at a reduced scatter transmission. By orienting long axes A of radiopaque strips 12 obliquely to the sweep S of the grid 1, the strips 12 being separated by air interspaces 13 can be performed with a sufficient own stiffness that no aluminum top and bottom covers are needed. The planes of downward lateral faces 12' intersect each other in an upward decentration line D.sub.+ and the planes of upward lateral faces 12" intersect each other in a downward decentration line D.sub.-. In a preferred embodiment of the invention the grid 1 is inclined during the sweep S so that the convergent line of the grid continues to pass through the tube focus.