Other

Digiray Corporation

Richard D Albert

Dale W Fitting

William P Dube

Thomas A Siewert

David L Reyna

The present invention relates to x-ray diffraction measurement by using moving x-ray source x-ray diffraction. The invention comprises a raster-scanned x-ray source, a specimen, a collimator, and a detector. The x-ray source is electronically scanned which allows a complete image of the x-ray diffraction characteristics of the specimen to be produced. The specimen is placed remote from the x-ray source and the detector. The collimator is located directly in front of the detector. The x-rays are diffracted by the specimen at certain angles, which cause them to travel through the collimator and to the detector. The detector may be placed in any radial location relative to the specimen in order to take the necessary measurements. The detector can detect the intensity and/or the wavelength of the diffracted x-rays. All information needed to solve the Bragg equation as well as the Laue equations is available. The x-ray source may be scanned electronically or mechanically. The present invention is used to perform texture analysis and phase identification.

Method and apparatus for diffraction measurement using a scanning x-ray source

X-ray images are produced on a monitor display screen by situating the subject between a detector having a minute x-ray sensitive area and an x-ray source having an extensive anode plate on which an x-ray origin point is swept in a raster pattern similar to the raster of the display monitor. Operating parameters of the x-ray source are controlled by digital data processing circuits which enable magnification of operator selected areas of the image by reducing the size of x-ray source raster pattern and repositioning of the raster pattern on the anode plate in response to operator actuation of one or more computer input devices. In the preferred form, the system also enables image enhancements and control of image characteristics such as contrast and brightness in response to actuations of the input devices or in response to programming. X-ray exposure and image acquisition time may be reduced by operator selection of only specific areas of particular interest for high resolution scanning. In the preferred form, the apparatus can detect a particular gray level in the image data and relocate the scan to image the region where the gray level is found. This enables fixed imaging of a moving object.

Method and apparatus for digital control of scanning x-ray imaging

Method and apparatus for digital control of scanning X-ray imaging

X-ray examination of objects, which may be very large objects such as aircraft, boat hulls or lengthy pipelines, is accomplished with an x-ray source having a moving x-ray origin point that is scanned in a raster pattern. At least one x-ray detector having a very small x-ray sensitive area is disposed behind or within the object and provides an output signal indicative of internal characteristics of an adjacent region of the object. The source and detector undergo relative travel at least in a lateral direction during the examination to provide a sequence of different x-ray views that may include views of successive regions of the object, views from different angles and stereo views. X-ray images are produced at one or more monitor screens by sweeping a point of light in a raster pattern corresponding to that of the x-ray source while modulating the intensity of the point of light in accordance with the output signal of the detector. An array of spaced apart detectors may be used to simplify examination of large objects or to speed examination of small objects.

Multiple image scanning X-ray method and apparatus

Tomographic or sectional X-ray images (46) of a subject (32) are obtained rapidly by a method and apparatus that do not inherently require motion of the X-ray source (12) and detectors (13) or motion of the subject in order to generate the tomographic image data. In the source, a charged particle beam (17) is directed to a broad target plate (18) and raster scanned to produce a moving X-ray origin point (19). X-ray count values are obtained at a plurality of spaced apart detection points (D1, D2, D3, D4, D5, D6, D7) situated at the opposite side of the subject from the source. Successive count values from a first detection point are combined with successive count values from at least one other detection point that originated at a later time in the course of the raster scan to provide a sequence of composite data values. Display of an image of at least a portion of the raster scan which exhibits variations between successive values of the composite data provides an image in which data from a specific plane (31a, 31b) within the subject is emphasized while data from other planes is suppressed. The apparatus may be compact and inexpensive in comparsion with tomographic installations that are dependent on precisely controlled motion of components or the subject during scanning.

Method and apparatus for scanning X-ray tomography

The distribution of one or more chemical elements within an object is detected by directing primary x-rays to successive points along a scan path on the object and by analyzing the energies of fluorescent x-rays emitted from the successive points to identify characteristic x-rays of the element. In the preferred form, a moving primary x-ray origin point is established by sweeping an electron beam along a broad target plate in a raster pattern corresponding to the desired scan path on the object. A collimator between the target plate and the object has x-ray transmissive zones alternated with x-ray absorbent zones to assure that primary x-rays from the moving origin point reach only corresponding successive points on the object. High precision with a minimum of structural complication is realized by scanning electronically rather than with a mechanical system.

Scanning x-ray spectrometry method and apparatus

A collimator (21, 38, 38A) transmits intercepted X rays or the like along an array of predetermined spaced apart paths (22, 22A), which may be parallel or convergent, while absorbing intercepted radiation which is traveling in other directions. A laminated construction of the collimator provides for an extremely large number of very minute and closely spaced radiation passages (42, 42A) which may have a noncircular cross section to increase transmissivity. The laminated construction also reduces the amount of heavy and sometimes costly radiation absorbent material required in the collimator, enables precise control of the transmitted radiation paths and facilitates the establishing of a desired focal point for the paths. Photoetching techniques, including optical image reduction, are used in the manufacture of the collimator laminations. In some variations of the method, the radiation absorbent material is plated onto the laminations.

Method of manufacture of laminate radiation collimator

Visual display of dental, medical or other radiographic images is realized with an X-ray tube in which an electron beam is scanned through an X-Y raster pattern on a broad anode plate, the scanning being synchronized with the X-Y sweep signals of a cathode ray tube display and the intensity signal for the display being derived from a small X-ray detector which receives X-rays that have passed through the subject to be imaged. Positioning and support of the detector are provided for by disposing the detector in a probe which may be attached to the X-ray tube at any of a plurality of different locations and by providing a plurality of such probes of different configuration in order to change focal length, to accommodate to different detector placements relative to the subject, to enhance patient comfort and to enable production of both periapical images and wider angle pantomographic images. High image definition with reduced radiation dosage is provided for by a lead glass collimator situated between the X-ray tube and subject and having a large number of spaced-apart minute radiation transmissive passages convergent on the position of the detector. Releasable mounting means enable changes of collimator in conjunction with changes of the probe to change focal length. A control circuit modifies the X-Y sweep signals applied to the X-ray tube and modulates electron beam energy and current in order to correct for image distortions and other undesirable effects which can otherwise be present in a scanning X-ray system.

Scanning radiographic method

Focusing radiation collimator

Laminate radiation collimator

A method and apparatus for producing X-rays having any selected one of a plurality of specific different wavelength spectra greatly facilitates X-ray fluorescence analysis of samples to detect constituent elements. In the X-ray source, an electron beam is directed to any selectable one of an array of primary targets of different composition. X-rays from the selected primary target may be utilized directly or caused to impinge on any selected one of a plurality of secondary targets, which are also each of differing composition to cause the secondary target to emit a specific X-ray spectrum characteristic of that secondary target. Analysis of the X-ray fluorescence from a sample irradiated by a plurality of different specific selected X-ray spectra enables identification and measurement of particular chemical elements in the sample.

Selectable wavelength X-ray source, spectrometer and assay method

Examination of dental patients or other subjects (14) with a radiographic system (11) having a scanning X-ray source (17) and a collimator (58) with a plurality of passages (62) for directing X rays to a detector (51) is facilitated by an image region selector (12) which is separate from the source. The selector (12) includes the detector (51) and means (64) defining the collimator position at which the collimator passages (62) are directed towards the detector (51). The selector (12) may be positioned and independently supported, to establish the region to be imaged, prior to the time that the relatively heavy and bulky X-ray source (17) is maneuvered into position for making the examination.

Image region selector for a scanning X-ray system

Radiographic images are produced by situating a subject (13) between a scanning x-ray source (16) and an x-ray detector (14) to produce electrical signals indicative of variations of x-ray transmissivity in different regions of the subject (13). A signal processing system (11) enables simultaneous display of a plurality of visible images at a plurality of display devices (52 to 55) with each image emphasizing a different aspect of the information generated by a given scanning of the subject. A feedback circuit (68) from the detector (14) to the x-ray source (16) maintains the average level of the detector signal constant while allowing short term fluctuations so that only abrupt or brief changes of x-ray transmissivity in the subject are visible in a first image at a first display device (52). A second image signal circuit (93) recovers the data suppressed by the feedback circuit (68) to enable a full contrast range image to be presented at another display device (53) and to enable display at additional display devices (54, 55) of still more images, each of which emphasizes a different selected contrast range from the total range of subject transmissivity variations developed by the scanning of the subject (13). Radiation exposure of the subject (13) is reduced by enabling extraction and display of a greater amount of information from a given scanning of the subject (13).

Plural image signal system for scanning x-ray apparatus

Scanning radiographic apparatus

A plurality of radiographic images of a subject are obtained simultaneously by situating the subject between a scanning X-ray source and an X-ray detector. The source has an electron beam which is swept through a raster pattern on a broad target to produce a moving X-ray origin point while the detector has an effective radiation-sensitive area which is very small in relation to the raster pattern. The X-axis and Y-axis beam deflection signals which control the X-ray source are also transmitted to both sets of raster signal terminals of a dual-image oscilloscope of the form having two deflectable electron beams for producing two separate images at a display screen. Both intensity signal terminals of the oscilloscope receive processed X-ray count signals from the detector through separate signal channels so that a pair of radiographic images of the scanned region of the subject are generated at the display screen. Separate signal processing circuits in each channel may be adjusted to have different gain factors and to establish different base levels and peak levels for the intensity signals enabling each radiographic image to emphasize a different aspect of the scanned region of the subject as each image may have a different contrast range. The plural images taken in conjunction exhibit contrast ranges which may exceed the contrast limitations of a single oscilloscope image or the similar limitations of photographic film which may be used to record the oscilloscope display.

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Danville, CA, United States of America

Richard D Albert