With Solid-state Image Detector Patents (Class 378/98.8)
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Patent number: 6895078Abstract: An X-ray examination apparatus includes an X-ray source, an X-ray detector and an exposure control system. The exposure control system is arranged to control the X-ray source so as to perform a test exposure at a low X-ray dose and to perform an X-ray exposure at a higher X-ray dose. The X-ray detector applies a control signal resulting from the test exposure to the exposure control system and the X-ray source is adjusted on the basis of this control signal. The X-ray exposure produces an X-ray image and the X-ray detector supplies an image signal representing this X-ray image. The exposure control system is arranged to adjust the X-ray detector to a low spatial resolution during the test exposure and to a high spatial resolution during the X-ray exposure. The X-ray detector preferably includes a sensor matrix having sensor elements arranged in columns and rows. The spatial resolution is adjusted by deriving the control signal and the image signal from large and small groups of sensor elements, respectively.Type: GrantFiled: March 24, 2003Date of Patent: May 17, 2005Assignee: Koninklijke Philips Electronics N.V.Inventors: Peter Lex Alving, Albert Louw Faber
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Patent number: 6890098Abstract: An imaging system and method for using the same is disclosed. The imaging system includes an x-ray detection array or plurality of detection arrays, a point x-ray source, and a controller. The point x-ray source moves relative to a detection array, each of the x-ray detectors subtending a solid angle at the point source that depends on the relative position of the point source and the detection array and on the location of the detector in the detection array. The signal generated by each x-ray detector depends on a calibration parameter that is independent of the solid angle subtended by that x-ray detector at the point source. The controller stores a table of calibration values that determines the calibration parameter for each of the x-ray detectors. The controller corrects the signals generated by the x-ray detectors for solid angle and for variations in the calibration parameter.Type: GrantFiled: November 22, 2002Date of Patent: May 10, 2005Assignee: Agilent Technologies, Inc.Inventors: S. Jeffrey Rosner, Russell Iimura
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Patent number: 6891923Abstract: A scheme for enabling proper radiation sensing to be performed without establishing a synchronous connection by generating radioscopic and sensing timings of an image sensor, includes a timing prediction unit for predicting an x-ray pulse timing on the basis of a detection value of a first X-ray detection unit, and outputting the predicted radiation pulse timing, and a drive control unit for effecting drive control of a second X-ray detection unit on the basis of an output of the timing prediction unit, thereby making it possible to perform the proper radiation sensing without establishing the wired or wireless online synchronous connection.Type: GrantFiled: April 15, 2003Date of Patent: May 10, 2005Assignee: Canon Kabushiki KaishaInventor: Osamu Tsujii
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Patent number: 6891926Abstract: An apparatus includes a sensor and a bundle of optical fibers. The bundle of optical fibers has a first end and a second end. The bundle of optical fibers at the first end extends in a first fiber direction and defines a first section plane that is normal to the first fiber direction. The first end defines a first end plane that is obliquely oriented with respect to the first section plane. The bundle of optical fibers at the second end extends in a second fiber direction and defines a second section plane that is normal to the second fiber direction. The second end defines a second end plane that is obliquely oriented with respect to the second section plane. The sensor is disposed in a confronting relation with the second end.Type: GrantFiled: August 9, 2001Date of Patent: May 10, 2005Assignee: Dalsa, Inc.Inventors: Douglas Raymond Dykaar, Colin J. Flood
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Patent number: 6888969Abstract: A pixel sensing subsystem (110) for a solid state image sensor includes frame timing logic (114) that produces a frame timing signal indicative of an end-of-frame time and a beginning-of-frame time and reset logic (116) that produces a reset signal for a charge accumulator of pixel sensing electronics. The reset logic (116) asserts the reset signal at least once between the end-of-frame time and the beginning-of-frame time to prevent saturation of the pixel sensing element.Type: GrantFiled: September 11, 2000Date of Patent: May 3, 2005Assignee: General Electric CompanyInventors: Scott William Petrick, Roland Frederick Saunders, Douglas I. Perry
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Patent number: 6885725Abstract: Sensitivity information on the sensitivities of the channels of a flat x-ray detector (3) is used for sensitivity correction of an image formed by irradiation of a subject with x-rays and read out of the flat x-ray detector (3). The collection of sensitivity information is started when a signal for starting the collection of the sensitivity information is sent to a sensitivity information collection control means (11) from an operator console (12). The sensitivity information collection control means (11) sends an irradiation start signal for starting irradiation with calibration light to calibration light control means (10). The calibration light control means (10) controls calibration light irradiation means (9) so that a desired intensity of light may be applied to the inside of the flat x-ray detector (3). Thus, a calibration light reception signal outputted from the flat x-ray detector (3) is stored as sensitivity information in sensitivity information storage means (5).Type: GrantFiled: October 25, 2001Date of Patent: April 26, 2005Assignee: Hitachi Medical CorporationInventor: Katsumi Suzuki
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Patent number: 6879660Abstract: A technique is provided in which a gain correction map derived for a detector at one X-ray spectrum may be adapted to accommodate images acquired by the detector at a different X-ray spectrum. The technique accounts for the physical variations in the detector which may produce spectrally-sensitive artifacts as well as for the particular image acquisition conditions. A technique is also provided for correcting edge artifacts in an acquired image by measuring median signal intensity within columns or rows of the image and deriving correction factors for the respective edge columns or rows based upon the trends of the median signal intensities. A technique is also provided for storing detector attributes during a manufacturing calibration process and accessing them during system operation such that a suitable gain correction factor is employed based upon the spectrum and operating conditions.Type: GrantFiled: December 18, 2002Date of Patent: April 12, 2005Assignee: General Electric CompanyInventors: Paritosh Jayant Dhawale, Douglas Albagli
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Patent number: 6876723Abstract: A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.Type: GrantFiled: July 1, 2003Date of Patent: April 5, 2005Assignee: The United States of America as represented by the Department of EnergyInventors: Peter M. Celliers, Franz A. Weber, Stephen J. Moon
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Patent number: 6873361Abstract: An image sensor (21) has a plurality of chips (31). Each chip (31) has a plurality of converter (33) for converting incident beams into electric signals and a plurality of electric signal storages (35). The converters (33) are arranged in one row or a plurality of rows in the vicinity of the first end portion (31a) of the chip (31). Each electric signal storage (35) extends from the converter (33) to the second end portion (31b) opposite to the first end portion (31a). The first end portion (31a) of each chip (31) is shifted relative to the first end portion (31a) of an adjacent chip (31) so that the row of the converters (33) of the respective chips (31) are stepwise exposed.Type: GrantFiled: January 27, 2000Date of Patent: March 29, 2005Assignees: Takeharu Etoh, Shimadzu CorporationInventor: Takeharu Etoh
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Patent number: 6868138Abstract: A method, processor and computed tomography (CT) machine for generating images utilizing high and low sensitivity data collected from a flat panel detector having an extended dynamic range. Hardware modifications for extending the dynamic range include grouping pixel rows and pixel columns into clusters of two. The sensitivity of the rows/columns is modified by positioning optical masks that have different transparencies for different rows/columns. Software modifications for extending the dynamic range include taking two correlated exposure scan measurements at each angle and combining the two data sets into one scan prior to image reconstruction. This method uses a spatially varying pixel exposure method where several adjacent pixels are clustered and each cluster has a different sensitivity. The signals of these clusters are combined to form one image effectively producing an increased dynamic range.Type: GrantFiled: May 29, 2002Date of Patent: March 15, 2005Assignee: The Regents of the University of MichiganInventors: Neal H. Clinthorne, Predrag Sukovic
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Patent number: 6862338Abstract: There are provided a photoelectric conversion film converting an x-ray to a charge, a switching element composed of a transistor, of which a gate is connected to a corresponding scanning line, a source is connected to the photoelectric conversion film, and a drain is connected to a corresponding signal line, and a accumulation element connected to the photoelectric conversion film and the switching element, accumulating the charged produced in the photoelectric conversion element, a scanning line driving circuit driving the scanning lines, and a signal detection circuit connected to the signal lines and reading out the charge accumulated in the accumulation element. A potential of the photoelectric conversion film and a gate potential of the switching element is set such that an absolute value of a gate-source voltage of the switching element decreases when the charge is accumulated in the accumulation element.Type: GrantFiled: May 13, 2003Date of Patent: March 1, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Akira Kinno, Mitsushi Ikeda
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Patent number: 6858159Abstract: Hafnium oxide HfO2 scintillator compositions are doped with titanium oxide and at least an oxide of a metal selected from the group consisting of Be, Mg, and Li. The scintillator compositions can include sintering aid material such as scandium and/or tin and a rare earth metal and/or boron for improved transparency. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power. The scintillators can be used as detector elements in X-ray CT systems.Type: GrantFiled: March 28, 2002Date of Patent: February 22, 2005Assignee: General Electric CompanyInventor: Robert Joseph Lyons
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Patent number: 6856670Abstract: An X-ray diagnostics installation has an X-ray tube, a voltage generator, a solid state X-ray detector, an image system and a playback device. The solid state X-ray detector is fashioned flexible and includes a flexible housing, a flexible substrate with a matrix of thin-film transistors (TFT), and a flexible X-ray converter.Type: GrantFiled: July 26, 2002Date of Patent: February 15, 2005Assignee: Siemens AktiengesellschaftInventor: Martin Hoheisel
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Patent number: 6854885Abstract: The invention relates to a method for the correction or compensation of individual differences between the conversion characteristics of the image sensors (11) and the processing units (12) of an X-ray detector which are connected thereto. It is assumed that a functional relationship in conformity with GW=Fi(Lij(?)) exists between the quantity of radiation (?) entering the detector and the grey value (GW) resulting therefrom for a pixel (j, i), where Lij describes the approximately linear behavior of the sensor arrangement (10) and Fi the non-linear behavior of the processing unit (12). For the inverse value Lij?1 a linear model function is used and for the inverse value Fi?1 a non-linear model function is used with parameters which can be calculated from calibration measurements with different radiation quantities (?k).Type: GrantFiled: September 27, 2002Date of Patent: February 15, 2005Assignee: Koninklijke Philips Electronics N.V.Inventors: Hans-Aloys Wischmann, Michael Overdick, Ralf Schmidt, Roelant Visser
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Patent number: 6851852Abstract: The invention concerns methods and devices for obtaining a radiographic image of a tooth and its surrounding environment. The method and the device are essentially characterized in that cylindrical rods produced from a material capable of transforming X-rays into light rays are arranged side by side for receiving the X-rays emitted by a source after they have passed through the tooth and its surrounding environment so as to both guide them and transform them into light rays, means thereafter converting said light rays into electric signals which are processed to produce the radiographic image.Type: GrantFiled: August 29, 2000Date of Patent: February 8, 2005Assignee: Trophy RadiologieInventor: Francis Mouyen
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Patent number: 6853707Abstract: An x-ray shielded imaging detector is disclosed. In one embodiment, the x-ray shielded imaging detector comprises a scintillator, a photodetector, and an optical connection between the scintillator and the photodetector. The x-ray shielded imaging detector also includes a first high density shielding material adjacent the optical connection. The first high density shielding material absorbs x-ray energy and attenuates it before the x-ray energy reaches the photodetector when the x-ray energy impinges on the x-ray shielded imaging detector at an angle other than perpendicular to a major axis of the scintillator and the photodetector. Other embodiments and related methods of operating an x-ray system are also disclosed.Type: GrantFiled: September 5, 2002Date of Patent: February 8, 2005Assignee: Agilent Technologies, Inc.Inventor: Ronald K Kerschner
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Patent number: 6847698Abstract: When a phototimer unit is used for exposure control, a deterioration in a S/N ratio occurs, and optimal exposure cannot be performed due to a deviation from a proper image sensing position and the like. Therefore, there is provided a radiation image sensing apparatus comprising an X-ray image sensing panel which is capable of non-destructive reading and adapted to sense an object image by allowing radiation from an X-ray source to pass through an object, and a control circuit adapted to perform control to stop emission of radiation from the X-ray source on the basis of a signal obtained from the X-ray image sensing panel by non-destructive reading in the image sensing operation.Type: GrantFiled: July 30, 2001Date of Patent: January 25, 2005Assignee: Canon Kabushiki KaishaInventors: Noriyuki Kaifu, Kazuaki Tashiro, Osamu Yuki
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Patent number: 6847042Abstract: An apparatus for detecting X-rays comprises a scintillator which emits a plurality of photoelectrons upon being impacted by an X-ray photon. The photoelectrons are amplified in a gas electron multiplier and the resultant photoelectrons are accumulated on a two dimensional array of charge collection electrodes. Electrical signals are produced which indicate the quantity of photoelectrons which strike each charge collection electrode. A processor determines a location of the X-ray photon strike by analyzing the spatial distribution of the photoelectrons accumulated by the array of charge collection electrodes. The intensity of the X-ray photon is determined from the number of accumulated photoelectrons.Type: GrantFiled: June 19, 2003Date of Patent: January 25, 2005Assignee: GE Medical Systems Global Technology Co., LLCInventors: Manat Maolinbay, Paul R. Granfors
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Patent number: 6840674Abstract: The invention relates to a method for the calibration of a radiation sensor, in which method a first calibration takes place with external radiation x and an internal signal s of the radiation sensor, and in which later calibrations are carried out exclusively with the internal signal. This enables the calculation of an approximate value x*(t) for the quantity of radiation x(t) absorbed in a radiation sensor (10) while taking into account a behavior of the radiation sensor that changes in time. First the primary characteristic ft1(x) is measured at a first instant t1; this characteristic describes the dependency of an output signal o on the absorbed quantity of radiation x. At the same time the secondary characteristic gt2(s) is measured, which characteristic describes the dependency of the output signal o on an internal signal s. The signals s and x should together form an intermediate signal w that is further processed with a function D(w,t) that varies in time in order to form the output signal o.Type: GrantFiled: March 20, 2002Date of Patent: January 11, 2005Assignee: Koninklijke Philips Electronics N.V.Inventors: Ralf Schmidt, Kai Eck
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Patent number: 6839407Abstract: The invention relates to an arrangement of sensor elements in which the sensor elements are arranged to detect electromagnetic radiation, such as X-rays or light, and to generate in response thereto a charge signal which corresponds to the radiation intensity. Furthermore, a sensor element includes means which enable determination of the incident radiation dose. The sensor elements in the arrangement form groups so that the outputs of all sensor elements of a group are coupled and the sensor elements of a group are preferably arranged so as to neighbor one another. This on the one hand enables determination of the dose in these zones while on the other hand images of lower resolution can be formed simply by combining output signals of a plurality of sensor elements. An arrangement of this kind can be used, for example, in an X-ray diagnostic device or in an optical image acquisition system.Type: GrantFiled: November 15, 2002Date of Patent: January 4, 2005Assignee: Koninklijke Philips Electronics N.V.Inventors: Augusto Nascetti, Michael Overdick
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Publication number: 20040262536Abstract: As a europium-activated rare earth oxysulfide phosphor with an enhanced X-ray absorption coefficient for direct-X-rays, a lutetium oxysulfide phosphor has been shown to be preferred, wherein said phosphor further prompt emits red light, which makes it particularly suitable for use as a scintillator material in a device for direct-radiography.Type: ApplicationFiled: June 29, 2004Publication date: December 30, 2004Inventors: Rudy Van den Bergh, Paul Leblans
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Publication number: 20040258207Abstract: A radiographic apparatus removes lag-behind parts from radiation detection signals taken from an FPD as X rays are emitted from an X-ray tube, on an assumption that the lag-behind part included in each X-ray detection signal is due to an impulse response formed of exponential functions, N in number, with different attenuation time constants. The lag-behind parts are removed by using impulse responses corresponding to variations in the sensor temperature of the FPD. X-ray images are created from corrected radiation detection signals with the lag-behind parts removed therefrom.Type: ApplicationFiled: May 26, 2004Publication date: December 23, 2004Inventors: Shoichi Okamura, Toshinori Yoshimuta
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Publication number: 20040258206Abstract: An apparatus for detecting X-rays comprises a scintillator which emits a plurality of photoelectrons upon being impacted by an X-ray photon. The photoelectrons are amplified in a gas electron multiplier and the resultant photoelectrons are accumulated on a two dimensional array of charge collection electrodes. Electrical signals are produced which indicate the quantity of photoelectrons which strike each charge collection electrode. A processor determines a location of the X-ray photon strike by analyzing the spatial distribution of the photoelectrons accumulated by the array of charge collection electrodes. The intensity of the X-ray photon is determined from the number of accumulated photoelectrons.Type: ApplicationFiled: June 19, 2003Publication date: December 23, 2004Inventors: Manat Maolinbay, Paul R. Granfors
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Publication number: 20040247078Abstract: An X-ray light emitting phosphor film (22) such as a CsI film that converts an X-ray to light is formed on an input substrate (21) constituting an input part of an X-ray image detector. A surface portion of the X-ray light emitting phosphor film (22) is irradiated with high-energy light having a wavelength of 500 nm or less. The surface portion of the X-ray light emitting phosphor film (22) is locally sublimated and/or fused to be flattened by the irradiation with the high-energy light. The use of the high-energy light such as a laser beam makes it possible to efficiently and uniformly flatten the surface portion of the X-ray light emitting phosphor film.Type: ApplicationFiled: February 24, 2004Publication date: December 9, 2004Inventor: Shirofumi Yamagishi
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Publication number: 20040234032Abstract: A radiography apparatus comprises an X-ray irradiation unit to irradiate an object with radiation, an X-ray detector which converts radiation projection images obtained by transmission through an object into signals and is capable of non-destructive readout of the signals, and an image analyzing unit for analyzing the signals read out by non-destructive readout from the X-ray detector. This allows information relating to the radiation which has been transmitted through an object such as a subject to be quickly comprehended.Type: ApplicationFiled: May 14, 2004Publication date: November 25, 2004Applicant: Canon Kabushiki KaishaInventor: Makoto Nokita
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Patent number: 6823038Abstract: A detector array for detecting X-rays has a number of sensor elements that each have a scintillator element, which is sensitive to X-rays, and a photo-electrical transducer optically coupled thereto. An intermediate areas separating adjacent scintillator elements from one another is present between each two adjacent scintillator elements. Scintillator material is present in the intermediate area. In a production method for such a detector array for detecting X-rays, separating channels are introduced into a layer that is composed of scintillator material, which is sensitive to X-rays, without completely separating the layer.Type: GrantFiled: March 6, 2002Date of Patent: November 23, 2004Assignee: Siemens AktiengesellschaftInventor: Thomas Von Der Haar
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Patent number: 6823044Abstract: An x-ray imaging system includes an x-ray source for projecting imaging radiation onto a sampled object that is secured by a support member and a detector support assembly having multiple detecting modules distributed in a sparse configuration for detecting imaging radiation that has passed through the object. The x-ray source and the detector support assembly are on opposite sides of the support member. Relative displacement is provided between the object and the imaging radiation. By providing the relative displacements and illuminating the object with pulses of imaging radiation at selected intervals, a time series of successive sub-images corresponding to overlapping regions of the object is captured by each module. Computational algorithms combine the captured sub-images to form a composite three-dimensional description of the sampled object. There are multiple pulses of x-ray illumination for each region of the object, and each pulse irradiates more than one detecting module.Type: GrantFiled: November 21, 2001Date of Patent: November 23, 2004Assignee: Agilent Technologies, Inc.Inventor: S. Jeffrey Rosner
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Patent number: 6823039Abstract: A computed tomography apparatus has a gantry with an X-ray source and an x-ray detector, and at least one further, curved solid-state radiation detector that is movable into and out of the beam path of the x-ray source is provided in the gantry.Type: GrantFiled: June 20, 2002Date of Patent: November 23, 2004Assignee: Siemens AktiengesellschaftInventors: Martin Hoheisel, Hartmut Sklebitz
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Patent number: 6819740Abstract: An X-ray diagnosis apparatus having a flat panel detector which converts an X-ray into an electric signal, comprises extracting means for extracting a noise element, which is stable in a row direction and fluctuant in a column direction, included in an X-ray image obtained on the basis of the electric signal, and subtracting means for subtracting the noise element extracted by the extracting means from the X-ray image.Type: GrantFiled: September 9, 2002Date of Patent: November 16, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Akihito Takahashi, Michitaka Honda
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Patent number: 6816572Abstract: A method of processing dual energy images. The method includes obtaining a first image generated at a first energy level and obtaining a second image generated at a second energy level different than the first energy level. The first and second images are pre-processed and decomposed to form a raw soft-tissue image and a raw bone image. The raw soft-tissue image is post-processed to form a processed soft-tissue image and the raw bone image is post-processed to form a processed bone image. The processed soft-tissue image and the processed bone image are then display processed.Type: GrantFiled: March 8, 2002Date of Patent: November 9, 2004Assignee: GE Medical Systems Global Technology Co., LLCInventors: Kadri Nizar Jabri, Gopal B. Avinash, Amber Elaine Rader, Renuka Uppaluri, John Michael Sabol, Francois Serge Nicolas
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Publication number: 20040200971Abstract: A radiographic image is obtained by combining at least two radiographic sub-images acquired by at least an upper and lower 2-dimensional radiation sensor having sensor pixels. The radiation sensitive area of the lower sensor is overlapped by the upper sensor. Overlap is preferably at least two pixel rows, but can also be limited to non-imaging parts of the upper sensor. The radiation sensors may comprise a radiation to light converting layer. Preferably the sensors are built using CMOS technology, exhibiting less radiation absorption outside the radiation sensitive area.Type: ApplicationFiled: April 5, 2004Publication date: October 14, 2004Inventor: Paul De Keyser
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Publication number: 20040202281Abstract: A method for providing X-ray image data signals corresponding to a selected portion of a two-dimensional image at an enhanced image resolution. During selective exposure of an X-ray receptor to X-ray radiation corresponding to the subject image, image pixel data corresponding to the region of interest (used pixels) are read out with normal pixel data pixel discharge times and at the normal pixel data rate, while image pixel data corresponding to the region not of interest (unused pixels) are read out also with normal pixel data pixel discharge times and at either the normal pixel data rate or an increased pixel data rate. During such pixel data readout intervals, the X-ray radiation exposure can be continuous or selectively pulsed.Type: ApplicationFiled: April 10, 2003Publication date: October 14, 2004Inventors: Richard E. Colbeth, Ivan P. Mollov
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Patent number: 6801598Abstract: A radiation sensing apparatus which includes a sensing unit for sensing a subject image to be obtained by irradiating a radiation from a radiation source to a subject, the sensing unit being capable of reading out non-destructively, and a detection circuit for detecting a start and/or a stop of irradiation of the radiation on a basis of a signal obtained from the sensing unit by the non-destructive read-out.Type: GrantFiled: October 22, 2002Date of Patent: October 5, 2004Assignee: Canon Kabushiki KaishaInventors: Kazuaki Tashiro, Noriyuki Kaifu
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Publication number: 20040188625Abstract: The invention relates to an image for creating digital images. In the image detector there are present means for receiving and storing administrative data.Type: ApplicationFiled: March 15, 2004Publication date: September 30, 2004Applicant: Sirona Dental Systems GmbHInventor: Ulrich Schulze-Ganzlin
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Patent number: 6798453Abstract: For accomplishing increase in S/N ratios, improvement in operability, and decrease of cost, a photoelectric conversion device comprises: a photoelectric conversion portion comprising a plurality of photoelectric conversion pixels arranged in row and column directions, a plurality of signal wires wired in the column direction, each of the signal wires connecting outputs of photoelectric conversion pixels arranged in the same column, and a plurality of control lines wired in the row direction, each of the control lines connecting control terminals for controlling signal output operation of photoelectric conversion pixels arranged in the same row; a plurality of analog memory means for storing analog voltages obtained from analog voltage conversion means for converting information charges based on the photoelectric conversion pixels to the analog voltages and for maintaining the analog voltages as outputs, each of the analog memory means being connected to each of the signal wires; and a plurality of A/D conversType: GrantFiled: November 16, 1998Date of Patent: September 28, 2004Assignee: Canon Kabushiki KaishaInventor: Noriyuki Kaifu
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Patent number: 6798864Abstract: Methods and apparatus are provided in a diagnostic X-ray system for reducing signal conversion time for a solid-state detector panel of the X-ray system in order to increase frame rate. A measurement of a set of induced signal offsets caused by time varying charge retention associated with the detector panel is performed during a phantom time segment prior to normal signal readout of the detector panel for a current image frame. A set of adjustment values is generated in response to the set of induced signal offsets. Subsets of signal values of the detector panel are read out to a pre-determined signal dynamic range as part of normal signal readout of the detector panel in response to the set of adjustment values, thus generating a set of normalized detector signals.Type: GrantFiled: March 28, 2002Date of Patent: September 28, 2004Assignee: GE Medical Systems Global Technology Company, LLCInventors: Scott William Petrick, Rowland Frederick Saunders, Richard Gordon Cronce, Jeffrey Alan Kautzer
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Patent number: 6795525Abstract: A radiation detecting apparatus has a conversion element having a semiconductor layer for directly converting a radiation into a charge; and a variable voltage source for applying an electric field to the semiconductor layer, wherein the variable voltage source applies a voltage of a plurality of values as to apply at least electric fields in an identical direction and in different strengths.Type: GrantFiled: June 21, 2002Date of Patent: September 21, 2004Assignee: Canon Kabushiki KaishaInventor: Toshio Kameshima
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Patent number: 6793848Abstract: The present invention provides terbium or lutetium garnet x ray scintillators activated with a rare earth metal ion, such as cerium, and treated by annealing in a controlled atmosphere comprising a predetermined amount of oxygen for a predetermined time and temperature to reduce radiation damage that would otherwise occur when the scintillator material is exposed to high energy radiation, such as the type of radiation required to use the scintillator for medical radiographic imaging and the like. In an embodiment, a single crystal or a polycrystalline scintillator comprising the general formula (Tb1−xLuxCey)3Al5O12 (where 0<×≦0.5, and y is in the range from about 0.0005 to about 0.2, and annealed at 1400° C. to 1500° C. in a controlled atmosphere comprising 1×10−6 to 0.22 atm oxygen shows an increased resistance to radiation damage.Type: GrantFiled: December 10, 2002Date of Patent: September 21, 2004Assignee: General Electric CompanyInventors: James Scott Vartuli, Steven Jude Ductos, Robert Joseph Lyons, Charles David Greskovich
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Publication number: 20040179650Abstract: The present invention is directed to a CT detector array having uniform cross-talk. Discontinuities in cross-talk between adjacent CT detectors of a CT detector array are minimized by increasing the cross-talk at the boundaries of adjacent CT detectors. Discontinuities throughout a CT detector contribute to artifact presence in a final reconstructed image, therefore, it is preferred that cross-talk throughout the CT detector array be relatively uniform. Reducing the width of reflector material between adjacent CT detectors increases the cross-talk between the CT detectors. This increase in cross-talk offsets the reduced cross-talk that typically occurs between scintillators, optical epoxy layers, and photodiodes at the CT detector interface. Cross-talk may also be increased by reducing the amount of chrome deposited in the reflector between CT detectors or reducing the levels of titanium oxide typically used in reflector layers.Type: ApplicationFiled: March 14, 2003Publication date: September 16, 2004Inventor: David M. Hoffman
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Publication number: 20040179651Abstract: A digital radiographic system in which a digital detector captures digital radiographic image data based on exposure of a patient to x-ray energy from an x-ray source, and assesses the acceptability of the digital radiographic image data at a time before the radiographic protocol has otherwise ended. Additionally, the digital radiographic system signals whether the digital radiographic image data is unacceptable based on the assessment, and allows for the initiation of a retake. The assessment may be made based on acceptability of the exposure and/or based on the acceptability of motion artifacts in the image. If the image is unacceptable, the technologist is alerted that a re-image is needed, with the alert being made in real-time immediately after the image is captured.Type: ApplicationFiled: March 12, 2003Publication date: September 16, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Xin Tong, Alexander Berestov
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Patent number: 6792070Abstract: Radiation is irradiated to an object, and the radiation, which carries image information of the object, is detected at a plurality of positions for image recording, which are set at different distances from the object, a plurality of radiation images of the object being thereby acquired. The acquisition of the radiation images is performed by use of a plurality of two-dimensional detectors, such that the radiation, which carries the image information of the object, at a position for image recording, which is remote from the object, is detected with a two-dimensional detector having a sensitivity higher than the sensitivity of a two-dimensional detector for detecting the radiation at a position for image recording, which is close to the object.Type: GrantFiled: October 15, 2002Date of Patent: September 14, 2004Assignee: Fuji Photo Film Co., Ltd.Inventor: Hideyuki Sakaida
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Patent number: 6792068Abstract: In a CT device with a multi-line detector system, different columns of the detector system can be connected to different numbers of electronic elements in order to read the signals generated in the detector elements. Thus, by using the detector systems, regions of the object to be examined can be scanned with a high resolution, and other regions can be scanned with a lower resolution. A high resolution in regions can therefore be achieved with a simplified and less expensive detector system, which generates a comparatively low data rate and amount of data.Type: GrantFiled: August 6, 2002Date of Patent: September 14, 2004Assignee: Siemens AktiengesellschaftInventors: Thomas Flohr, Bernd Ohnesorge
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Publication number: 20040174951Abstract: The present invention is directed to an improved CT detector scintillator to photodiode optical coupling. The CT detector utilizes a controlled air gap between the photodiode array and the scintillator array together with an anti-reflective layer on the scintillator array. To improve the absorption of light at the photodiode array, the photodiode array includes a textured light reception surface. By incorporating a textured layer with the photodiode array, the light collection efficiency of the photodiodes is improved. The textured layer may extend along an x- and/or z-axis and the texturing may be in different forms. For example, the textured layer may include a series of pyramidally-shaped protrusions.Type: ApplicationFiled: March 3, 2003Publication date: September 9, 2004Inventor: David M. Hoffman
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Publication number: 20040174953Abstract: An X-ray diagnosis apparatus comprises an X-ray tube for projecting X-rays onto a subject, a two-dimensional X-ray detector for detecting X-ray signals from the subject, an image processing means for generating image signals to perform image display of the X-ray signal from the two-dimensional X-ray detector, and an image displaying means for displaying the image signal, and further comprises a noise eliminating means for generating noise correction signals from the X-ray signal of two scanning lines adjacent to each other out of a plurality of scanning lines of the two-dimensional X-ray detector and eliminating noise in an X-ray signal of the scan lines by using the noise correction signal.Type: ApplicationFiled: January 23, 2004Publication date: September 9, 2004Inventors: Shigeyuki Ikeda, Katsumi Suzuki
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Publication number: 20040174952Abstract: The present invention is directed to a scintillator array having an integrated air gap. By integrating an air gap within the reflector, light collection efficiency is improved while simultaneously lowering cross-talk between scintillators. That is, implementing a reflector without chromium oxide (Cr2O3) increases light reflectivity and an air gap lowers cross talk through the reflector. To further improve the reflectivity, the base reflector material may be coated with a low index material and a reflective material such as silver.Type: ApplicationFiled: March 3, 2003Publication date: September 9, 2004Inventor: David M. Hoffman
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Patent number: 6782077Abstract: The object of the present invention is to provide a satisfactory image at a desired imaging timing by implementing grid movement control according to the time response characteristics of the radiation generation function and a decrease in time delay from an imaging request to actual irradiation. In order to achieve this object, a control device controls the actual irradiation instruction timing for an irradiation device on the basis of a pre-irradiation delay time as a time between an instruction and irradiation of actual irradiation of the irradiation device.Type: GrantFiled: March 29, 2001Date of Patent: August 24, 2004Assignee: Canon Kabushiki KaishaInventor: Akira Hirai
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Publication number: 20040159794Abstract: An image pickup apparatus or a radiation image pickup apparatus according to the present invention includes: a plurality of pixels which are two-dimensionally arranged on a substrate, each of the plurality of pixels including a set of a semiconductor conversion element that converts an incident electromagnetic wave into an electrical signal and a switching element connected with the semiconductor conversion element; a drive wiring which is commonly connected with the plurality of switching elements arranged in a direction; and a signal wiring which is commonly connected with the plurality of switching elements arranged in a direction different from the direction, the switching element including a first semiconductor layer, the semiconductor conversion element being formed after the switching elements are formed and including the second semiconductor layer formed after the first semiconductor layer is formed, in which the semiconductor conversion element has an electrode formed outside a region in which two ofType: ApplicationFiled: November 13, 2003Publication date: August 19, 2004Inventors: Toshiko Morii, Masakazu Morishita, Minoru Watanabe
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Patent number: 6778632Abstract: In an arrangement having an X-ray detector or a gamma detector with detector elements arranged in a matrix in row and column directions that form a detector surface with detection regions that are sensitive to X-rays or gamma radiation and insensitive intermediate regions, and a stray radiation grid or collimator of absorbent structure elements that is arranged over the detector surface, the absorbent structure elements proceed over the intermediate regions and are fashioned such that their detector-side center-to-center spacing in the row direction and/or column direction is greater by a whole-numbered factor than the center-to-center spacing of the detector elements in the same direction, and/or sections of the absorbent structure elements that proceed in one direction exhibit a lower height than sections that proceed in the respectively other direction.Type: GrantFiled: October 21, 2002Date of Patent: August 17, 2004Assignee: Siemens AktiengesellschaftInventors: Martin Hoheisel, Hartmut Sklebitz
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Publication number: 20040156473Abstract: An object of this invention is to appropriately execute automatic exposion control. A radiographic apparatus has a radiographic image detection section (62) which detects the radiographic image of an object and a plurality of radiation dose detection sections (631-634) which detect the dose of radiation from the object. The radiographic apparatus includes a control section (61) which decides the mode of use of the outputs from the plurality of radiation dose detection sections (631-634) on the basis of the arrangement state of the radiographic apparatus.Type: ApplicationFiled: January 26, 2004Publication date: August 12, 2004Inventors: Hideki Nonaka, Masakazu Morishita, Tatsuya Yamazaki, Isao Kobayashi, Osamu Tsujii, Akira Hirai, Toshikazu Tamura, Takamasa Ishii
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Patent number: 6775351Abstract: An apparatus and method used in intra-oral dental x-ray imaging equipment provides automatic detection of the x-ray emission in order to obtain timely transition to the image integration and acquisition phase with high level of rejection of false triggering induced by blemish defects of the image sensor or by variations of the ambient and temperature conditions. A solid state imager, such as a CCD image sensor, is continually clocked during the standby phase prior to irradiation from an X-ray source, so providing on same time an output signal proportional to the accumulated dark current and the continuous removal of the same. A control unit analyses the output signal of the imager, detects the variation caused by the start of the x-ray emission using appropriate threshold levels, and automatically triggers the imager to the image integration and acquisition phases.Type: GrantFiled: January 4, 2001Date of Patent: August 10, 2004Inventors: Gerardo Rinaldi, Venturino Gianfranco