Abstract: A flat panel x-ray imager includes a gain layer (charge multiplication layer) that facilitates imaging at low x-ray exposure levels. The gain layer can be a gas chamber or a solid state material operating in an avalanche mode.

Abstract: A shielding grid constructed of a radiation absorbing material for use with an array of discreet, non contiguous radiation sensors to protect such sensors from scattered radiation. The sensors each have a radiation sensitive area with a width and a length. In designing the grid a prototile having a prototile width and a prototile length is developed. The prototile width is equal to the radiation sensitive area width divided by an integer and the prototile length is also equal to the radiation sensitive area length divided by a integer. The prototile contains a motif contained solely within the prototile that forms a pattern when a plurality of prototiles sufficient to cover the array of discreet sensor are arrayed contiguously. The grid is constructed with the radiation absorbing material in this pattern.

Abstract: A flat panel x-ray imager includes a gain layer (charge multiplication layer) that facilitates imaging at low x-ray exposure levels. The gain layer can be a gas chamber or a solid state material operating in an avalanche mode.

Abstract: A panel for radiation detection having a plurality of sensors arrayed thereon. Each sensor includes a charge storage capacitor, a radiation sensitive layer over the charge storage capacitor and a dielectric layer over the radiation sensitive layer. The dielectric layer has an adjusted resistivity resulting in a time constant &tgr;=&rgr;&kgr;&egr;0 between 0.050 and 20 seconds, wherein &kgr; is the dielectric constant of the dielectric layer, and &egr;0 is the permitivity of free space. The radiation detection layer is a photoconductor, and the dielectric layer is, preferably, a linear segmented polyurethane.

Abstract: A radiation anti-scatter device comprising a grid and a grid driver connected to the grid for unidirectionaly moving the grid with a variable grid velocity along a path between a starting and an end position, and a method of providing such grid motion. The variable grid velocity may have a velocity profile V1=k1t for a first period and then V2=k2t−m for a second period, where V1 and V2 are velocity, k1 and k2 are constants, t is time, and m is an exponent having a value greater than 0. The anti-scatter device may be a component of a direct radiographic diagnostic imaging system which includes an image-producing element having an array of radiation detectors aligned in rows, and where the anti-scatter device is a grid having vanes oriented at an angle to the detector rows. Radiation emission may be synchronized with the grid motion to optimize a radiograph for a particular grid, radiation source, or examination procedure.

Abstract: An image capture panel including a substrate with a plurality of radiation detection sensors, a plurality of conductors connected one to each radiation detection sensor, a plurality of amplifiers connected to the sensors all on the substrate, and a field electrode having an peripheral edge mounted above the radiation detection sensors and the conductors. A shielding electrode may surround the field electrode peripheral edge or may completely cover the field electrode with a dielectric layer in-between. A shielding electrode may instead surround or completely cover each amplifier. The shielding electrode may be biased to ground via a resistor, and may be constructed of a conductive paint, such as silver paint.

Abstract: An X-ray image capture radiation detector for use in digital radiography is disclosed. The radiation detector has, in order, a dielectric substrate, a TFT transistor and a capacitor on the surface of the dielectric substrate, an insulating layer, a photoconductive layer over the insulating layer, a top dielectric layer, and a top conducting layer. The insulating layer prevents any direct charge transfer between the photoconductive layer and the capacitor.

Abstract: A method for the elimination of residual image artifacts from prior image exposure in an x-ray image obtained by exposing an x-ray image detector which includes a photoconductor to imaging x-ray radiation, wherein the residual image artifacts are eliminated by a process which includes obtaining and averaging pre and post exposure image data from the detector and subtracting the averaged pre and post exposure data from the image exposure data.

Abstract: A digital array for capturing a radiogram. The array includes a generally flat base on which there is mounted with a plurality of shock absorbing mounts a rigid support plate. A radiation electronic detection panel is mounted on the rigid plate in a way that the panel "floats" over the base. Electronic circuitry associated with the radiation detection panel is connected thereto with flexible connectors. A cover, which is transparent to X-ray radiation and opaque to visible radiation, is attached to the base to form a light tight enclosure for the panel. The top cover inner surface opposite the front surface of the radiation detection panel, is spaced from the detection panel front surface, and the detection panel is also spaced from the side walls.

Abstract: A radiation detection panel for X-ray imaging systems is made up of an assembly of radiation detector sensors arrayed in rows and columns. Each sensor includes a radiation detector connected to a charge storage capacitor. Each capacitor is connected to a diode. When proper biasing voltages are applied to the sensor, capacitor, and diode, the diode is reverse biased and radiation induced charges accumulate in the capacitor. When the biasing voltages are changed appropriately, the diode is forward biased and the stored charge flows from the capacitor to a detector. Both still and moving images may be displayed.

Abstract: An image capture panel includes a plurality of sensors arrayed adjacent to a substrate layer of dielectric material, and a radiation sensitive layer disposed over the sensors. The radiation sensitive layer is exposed to a first substantially uniform pattern of light radiation for partially neutralizing residual electrical charges trapped within the image capture panel. The radiation sensitive layer is then exposed to a second substantially uniform pattern of light radiation sufficient to neutralize substantially all residual electrical charges trapped within the image capture panel.

Abstract: An image capture panel includes a substrate layer of dielectric material having a top surface and a bottom surface. A plurality of sensors is arrayed in a matrix of rows and columns adjacent the top surface of the substrate layer. Each of the sensors has a switching device and a sensing element. A portion of the sensing element are really covers the switching device so as to be substantially coextensive therewith. Prefereably, the sensing element also extends over at least a part of the horizontal spacing and/or the vertical spacing which separates, respectively, each row of sensors and each column of sensors.

Abstract: Process and apparatus for reduced noise reception of frequency modulated electromagnetic signal transmissions employing at least three spatially displaced receiving channels. The received at least three signals are continuously sampled at a high frequency, and the sampled signals are compared to each other. As a result of this comparison one sampled signal is selected and used for the reconstruction of the original transmission. The process is repeated for each sampling.

Abstract: The present invention relates to an X-ray image capturing element comprising a panel having a layered structure, including a conductive layer comprising a plurality of discrete microplates having dimensions coextensive with an image pixel and a plurality of access electrodes and electronic components built on the panel, which allow access to the microplates for capturing and reading out a latent radiographic image captured in the panel in the form of stored electrical charges.

Abstract: An X-ray image capture element includes a dielectric substrate layer having a top surface and a bottom surface. A plurality of transistors is arrayed adjacent the top surface of the dielectric layer. A plurality of charge storage capacitors is also arrayed adjacent the top surface of the dielectric layer, each capacitor having a conductive inner microplate connected to at least one of the transistors. Conductive address lines and sense lines are disposed adjacent the top surface of the dielectric layer for electronically activating the transistors and individually accessing each of the capacitors. A photoconductive layer is disposed over the transistors, address and sense lines, and a top conducting layer is disposed over the photoconductive layer opposite the dielectric layer.

Abstract: An X-ray image capturing element comprising a panel having a layered structure, including a conductive layer comprising a plurality of discrete microplates having dimensions co-extensive with an image pixel and a plurality of access electrodes and electronic components built on the panel, which allow access to the microplates for capturing and reading out a latent radiographic image captured in the panel in the form of stored electrical charges.

Abstract: A method and apparatus for capturing digital radiographic images. More particularly, the present invention relates to a method and associated apparatus for reading varying electrical charges representing a latent radiographic image stored in a unique microcapacitor matrix structure to obtain an electrical signal representing a radiogram. The microcapacitor matrix structure or element comprises a first, electrically conductive, backing layer, a second photoconductive layer, a third dielectric layer and a plurality of conductive microplates having dimensions coextensive with a minimum resolvable picture element.

Abstract: An element, a device and an associated method for capturing radiographic images. More particularly, the present invention uses a unique microcapacitor matrix structure to hold varying electrical charges representing a latent radiographic image. The microcapacitor matrix structure or element comprises a first, electrically conductive, backing layer, a second photoconductive layer, a third dielectric layer and a plurality of conductive microplates having dimensions coextensive with a minimum resolvable picture element. The method comprises (a) preventing actinic radiation from impinging on the element, (b) applying an electric potential difference between the plurality of microplates and the backing layer, (c) impinging imagewise modulated X-ray radiation for a first time period onto the element, and (d) after the first time period, stopping the applying step.

Abstract: A method for capturing and displaying radiographic images. More particularly, the present invention uses a unique microcapacitor matrix structure to hold varying electrical charges representing a latent radiographic image which are subsequently rendered visible through toning.

Abstract: An exposure control system which permits accurate reproduction of optical density levels on a final image is characterized by a dynamically corrected look-up table. The look-up table is used to calculate each desired exposure intensity level for each image pixel on the basis of data obtained during the exposure and development of an immediately preceding image.