Abstract: A radiation image pickup device comprises temperature control means for maintaining the temperature of an X ray conversion layer to be substantially constant by performing a feedback process for controlling a voltage which is applied to the Peltier element based on the temperature of the X ray conversion layer. The temperature control means starts reading out an electric charge from each pixel (DU), then converts the electric discharge to voltage with a charge amplifier and in a period until an A/D conversion process for the voltage is completed, and restricts a variation in the voltage which is applied to the Peltier element.

Abstract: An image processing system of this invention includes a variation calculator for calculating a variation in pixel value of each pixel relative to adjacent pixels, and an edge degree calculating device for calculating, for one arbitrary pixel, an edge degree which expresses numerically a probability of the one pixel being an edge, based on variations of a peripheral pixel group consisting of the one pixel and surrounding pixels. According to the image processing system constructed in this way, whether edges or not can be evaluated with high accuracy even when the pixels undergoing noise.

Abstract: A radiation image pickup device comprises temperature control means for maintaining the temperature of an X ray conversion layer to be substantially constant by performing a feedback process for controlling a voltage which is applied to the Peltier element based on the temperature of the X ray conversion layer. The temperature control means starts reading out an electric charge from each pixel (DU), then converts the electric discharge to voltage with a charge amplifier and in a period until an A/D conversion process for the voltage is completed, and restricts a variation in the voltage which is applied to the Peltier element.

Abstract: A radiographic apparatus according to this invention stores, before an imaging event, offset images and gain correcting images corresponding to a plurality of storage times, and acquires a lag image and a radiographic image based on these stored images. Then, lag correction is carried out to remove lags, using the lag image, from the radiographic image. In this way, from the radiographic image taking into consideration the offset images and gain correcting images corresponding to the storage times, lags are removed using the lag image which similarly fakes into consideration the offset images and gain correcting images corresponding to the storage times. Lag-behind parts, including offset and gain components, are removed from radiation detection signals in a simple way.

Abstract: A radiographic apparatus according to this invention, when carrying out recursive computation, pixel groups consisting of detection pixels respectively corresponding to positions on a radiation detection device are sorted into locations subjected to the recursive computation and locations exempted from the recursive computation. For the locations subjected to the recursive computation, lag-behind parts are removed by the recursive computation to obtain corrected radiation detection signals. The recursive computation is not carried out at least for the locations exempted from the recursive computation. The lag-behind parts can be removed from the radiation detection signals, with a calculation amount for the recursive computation reduced by an amount corresponding to the recursive computation excluded.

Abstract: A radiographic apparatus according to this invention carries out lag correction by applying lag data based on a plurality of radiation detection signals acquired in time of non-irradiation before first irradiation, to both first and second radiation detection signals. Thus, lag correction is possible without acquiring lag components between the first irradiation and second irradiation. Also in the case of carrying out two radiation irradiations (first irradiation and second irradiation) for one image, lag-behind parts included in the radiation detection signals can be removed simply from the radiation detection signals.

Abstract: A radiographic apparatus according to this invention, when a predetermined operation relating to radiographic imaging is interposed during an emission of radiation, stops the emission temporarily, and also stops a recursive computation temporarily. With start of the predetermined operation, the emission is started again and also the recursive computation is started again. Radiation detection signals at the time of non-emission due to the temporary stop are acquired, and the recursive computation is carried out based on initial values derived from the radiation detection signals at the time of non-emission. The lag-behind parts are removed from the radiation detection signals with increased accuracy while reducing the trouble of radiographic images caused by the predetermined operation relating to radiographic imaging being interposed during an emission of radiation.

Abstract: An image processing system of this invention includes a variation calculator for calculating a variation in pixel value of each pixel relative to adjacent pixels, and an edge degree calculating device for calculating, for one arbitrary pixel, an edge degree which expresses numerically a probability of the one pixel being an edge, based on variations of a peripheral pixel group consisting of the one pixel and surrounding pixels. According to the image processing system constructed in this way, whether edges or not can be evaluated with high accuracy even when the pixels undergoing noise.

Abstract: With a radiographic apparatus according to this invention, a storage time for storing X-ray detection signals is a fixed predetermined time without regard to an irradiation time, and imaging is performed with only one type of storage time. Even with only one type of storage time, it is possible to read the X-ray detection signals stored for the fixed predetermined time for every one image, thereby obtaining stored frame data for multiple images, and to obtain X-ray images based on the multiple stored frame data associated with irradiation. Thus, imaging and signal processing can be performed with one type of storage time.

Abstract: A radiographic apparatus according to this invention carries out lag correction by applying lag data based on a plurality of radiation detection signals acquired in time of non-irradiation before first irradiation, to both first and second radiation detection signals. Thus, lag correction is possible without acquiring lag components between the first irradiation and second irradiation. Also in the case of carrying out two radiation irradiations (first irradiation and second irradiation) for one image, lag-behind parts included in the radiation detection signals can be removed simply from the radiation detection signals.

Abstract: A radiographic apparatus according to this invention stores, before an imaging event, offset images and gain correcting images corresponding to a plurality of storage times, and acquires a lag image and a radiographic image based on these stored images. Then, lag correction is carried out to remove lags, using the lag image, from the radiographic image. In this way, from the radiographic image taking into consideration the offset images and gain correcting images corresponding to the storage times, lags are removed using the lag image which similarly fakes into consideration the offset images and gain correcting images corresponding to the storage times. Lag-behind parts, including offset and gain components, are removed from radiation detection signals in a simple way.

Abstract: A radiographic apparatus according to this invention, when a predetermined operation relating to radiographic imaging is interposed during an emission of radiation, stops the emission temporarily, and also stops a recursive computation temporarily. With start of the predetermined operation, the emission is started again and also the recursive computation is started again. Radiation detection signals at the time of non-emission due to the temporary stop are acquired, and the recursive computation is carried out based on initial values derived from the radiation detection signals at the time of non-emission. The lag-behind parts are removed from the radiation detection signals with increased accuracy while reducing the trouble of radiographic images caused by the predetermined operation relating to radiographic imaging being interposed during an emission of radiation.

Abstract: A radiographic apparatus according to this invention, when carrying out recursive computation, pixel groups consisting of detection pixels respectively corresponding to positions on a radiation detection device are sorted into locations subjected to the recursive computation and locations exempted from the recursive computation. For the locations subjected to the recursive computation, lag-behind parts are removed by the recursive computation to obtain corrected radiation detection signals. The recursive computation is not carried out at least for the locations exempted from the recursive computation. The lag-behind parts can be removed from the radiation detection signals, with a calculation amount for the recursive computation reduced by an amount corresponding to the recursive computation excluded.

Abstract: Corrected X-ray detection signals are obtained by removing lag-behind parts through a recursive computation based on initial values determined from lag signal value (step T2). Thus, the lag-behind parts can be removed by taking into consideration lag signal values remaining at a starting point of the recursive computation. The lag signal values are dependent on the characteristic of an FPD (flat panel X-ray detector). By removing the lag-behind parts, with the lag signal values taken into consideration, the lag-behind parts are removed from X-ray detection signals with increased accuracy, without being influenced by the characteristic of the FPD.

Abstract: A radiographic apparatus obtains lag-free radiation detection signals with lag-behind parts removed from radiation detection signals taken from a flat panel X-ray detector as X rays are emitted from an X-ray tube. The lag-behind parts are removed by a recursive computation 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. X-ray images are created from the lag-free radiation detection signals.

Abstract: 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 a plurality of exponential functions with different attenuation time constants. When a single attenuation time constant and intensity are provisionally set, checking is made whether an attenuation to a noise level of X-ray detection signals occurs in an X-ray non-emission state following an X-ray emission state. When the set attenuation time constant and intensity are found appropriate (OK), the impulse response having the single exponential function is determined valid. Corrected radiation detection signals are obtained by removing the lag-behind parts using the impulse response determined.

Abstract: Corrected X-ray detection signals are obtained by removing lag-behind parts through a recursive computation based on initial values determined from lag signal value (step T2). Thus, the lag-behind parts can be removed by taking into consideration lag signal values remaining at a starting point of the recursive computation. The lag signal values are dependent on the characteristic of an FPD (flat panel X-ray detector). By removing the lag-behind parts, with the lag signal values taken into consideration, the lag-behind parts are removed from X-ray detection signals with increased accuracy, without being influenced by the characteristic of the FPD.

Abstract: In the radiographic apparatus according to this invention, when a radiographic mode designator 16 designates a non-standard radiographic mode, a signal corrector 15 uses defect information stored in one of non-standard image defect information memories 18B–18E for correcting X-ray detection signals outputted from an FPD 2. Since the pixel defect information for non-standard X-ray images is acquired by a pixel defect information converter 19 through a conversion from defect information for standard X-ray images stored in a standard image defect information memory 18A, it is unnecessary to collect output signals for pixel defect information acquisition from the FPD 2 all over again. As a result, abnormal X-ray detection signals due to defects of radiation detecting elements may be corrected promptly, regardless of how the radiation detecting elements are assigned to the pixels in the X-ray images.

Abstract: When performing a lag correction of a lag-behind part by eliminating the lag-behind part from an X-ray detection signal obtained, a plurality of X-ray detection signals in time of non-irradiation before X-ray irradiation in an imaging event, and a lag image based on the X-ray detection signals acquired. The lag correction performed by subtracting the lag image acquired from the X-ray detection signal. Thus, the lag-behind part is eliminated from the X-ray detection signal in a simple way.

Abstract: An apparatus according to the invention includes a response coefficient to dose relationship memory for storing, in advance, a relationship of correspondence between intensities of an exponential function for impulse response and X-ray doses. The intensities of the exponential function determine conditions relating to an impulse response in a recursive computation performed to remove lag-behind parts from X-ray detection signals outputted from an FPD, thereby to obtain corrected X-ray detection signals. An impulse response coefficient setter sets an impulse response coefficient corresponding to an X-ray dose for an object under examination based on the relationship of correspondence between intensities of the exponential function and radiation doses. A time lag remover performs the recursive computation for time lag removal, with the intensity of an exponential function set to correspond to the X-ray dose for the object under examination.