| Patent application number | Description | Published |
|---|
| 20090086888 | X-RAY CT APPARATUS AND IMAGE RECONSTRUCTION METHOD - An X-ray CT apparatus is provided for reducing the amount of computation at image reconstruction thereby to shorten an image reconstruction time. The X-ray CT apparatus comprises a cradle which moves in a horizontal direction to convey a subject to a photography space, an X-ray detector comprising a plurality of detecting clement rows, for obtaining projection data by a helical scan when the cradle is moved under acceleration/deceleration and at a constant velocity, and backprojection processing device for performing a backprojection process on the projection data. When image reconstruction is carried out using the projection data acquired when the cradle is moved under acceleration/deceleration, the backprojection processing device assumes a virtual image reconstruction plane P′ where the cradle is assumed to be moved at the constant velocity, with respect to an image reconstruction plane P of each view and backprojects projection data onto the virtual image reconstruction plane P′. | 04-02-2009 |
| 20090092224 | X-RAY CT APPARATUS - An X-ray CT apparatus enables decreasing the degradation of image quality and reducing futile exposure to X-ray in a helical shuttle scan. The X-ray CT apparatus comprises: a gantry rotating device having an X-ray generator for generating the X-ray and an X-ray detector for detecting the generated X-ray and transmitted through a subject; a gantry controller for performing the helical shuttle scan by reciprocally moving the gantry rotating device and the cradle; a scan condition setting device for setting the scan condition of the helical shuttle scan in a predetermined range in the direction of body axis of the subject; an X-ray projection data acquisition device for acquiring the X-ray projection data; a scan controller for controlling the scan as specified in the scan condition; and a image reconstruction device for performing the image reconstruction processing based on the X-ray projection data. | 04-09-2009 |
| 20090161822 | X-RAY CT APPARATUS AND IMAGE RECONSTRUCTING DEVICE - An X-ray CT apparatus includes image reconstructing device which specifies a first imaging range, a second imaging range and a third imaging range located between the first imaging range and the second imaging range in association with each position on a body axis of a subject, image-reconstructs a tomographic image included in the first imaging range using a first projection data amount necessary for image reconstruction of the tomographic image, image-reconstructs a tomographic image included in the second imaging range using a second projection data amount less than the first projection data amount, and image-reconstructs a tomographic image included in the third imaging range using a third projection data amount less than the first projection data amount and greater than the second projection data amount. | 06-25-2009 |
| 20100104313 | POWER SOURCE DEVICE AND IMAGE FORMING APPARATUS - A power source device includes an oscillator generating a clock, a frequency division unit dividing the clock to output a pulse, a sequence generation unit generating sequences “N” with respect to each switching of the pulse, a frequency division ratio setting unit setting frequency division ratio, a switching element driven by the pulse, and a piezoelectric transformer outputting alternating high voltage from a secondary-side when a primary-side is applied with voltage. The generated sequence and the set frequency division ratio are compared to output the pulses of fractional-M, −M+1 frequencies. An average frequency division ratio of the pulses of fractional-M, −M+1 frequencies determined by (M×α)+(M+1)×β/(α+β), where α and β respectively represent the number of pulses of “M” and “M+1” per unit time. The average frequency division ratio and frequency division ratio become equal at a sequence generation cycle and approximated in a period shorter than the sequence generation cycle. | 04-29-2010 |
| 20100172563 | X-RAY CT APPARATUS - An X-ray CT apparatus reconstructs a CT image (extended CT image) at each slice position lying outside a relative linear movement range at a helical scan or the like at low exposure and with high image quality. Scans each provided with a residence time are executed at relative linear movement start and end points (Zs and Zf). Projection data in a view range (F) corresponding to a predetermined view angle centering on a view (CVp | 07-08-2010 |
| 20100172564 | IMAGE RECONSTRUCTION METHOD AND X-RAY CT APPARATUS - An image reconstruction method includes a reconstruction algorithm of pixel data, weighting coefficients by which first projection data and second projection data at which a corresponding X-ray beam passes through a pixel lying on a reconstruction plane and which are opposite in view angle direction to each other, are to be multiplied, are calculated by equations each using a term of a distance between an X-ray generator and detector system and the reconstruction plane plus an offset distance at the acquisition of the projection data. | 07-08-2010 |
| 20100188011 | PIEZOELECTRIC TRANSFORMER DRIVING DEVICE, COLD-CATHODE TUBE INVERTER, COLD-CATHODE TUBE DRIVING DEVICE, AND IMAGE FORMING APPARATUS - A piezoelectric transformer driving device including: an oscillator; a frequency-divider outputting a pulse by dividing a clock signal from the oscillator by a frequency-divide ratio received thereto; a switching element driven by the pulse and intermittently applying a voltage to a primary side of a piezoelectric transformer; a frequency-divide ratio instructing unit holding a frequency-divide ratio instruction value of a real number having an integer part and an fractional part; a binarization unit binarizing the frequency-divide ratio instruction value into two different integer frequency-divide ratios and selectively outputting the frequency-divide ratios. The binarization unit adjusts an appearance ratio of the frequency-divide ratios such that an average of the frequency-divide ratios output from the binarization unit is equal to an average of the frequency-divide ratio instruction value. | 07-29-2010 |
| 20100202794 | POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS - A power supply device includes: an oscillator configured to output a clock signal; a pulse output unit configured to output a pulse by dividing the frequency of the clock signal; a switching element driven by the pulse; a piezoelectric transformer configured to intermittently receive a voltage from the switching element and to output a high alternating current voltage; a rectifier configured to convert the high alternating current voltage to a high direct current voltage; an output voltage conversion unit configured to convert the high direct current voltage to a low direct current voltage; a target setter configured to output a target value; and a comparison unit configured to compare the low direct current voltage with the target value and to output a comparison result. A frequency division ratio of the pulse is controlled according to the comparison result, and thereby is changed so as to obtain the target value. | 08-12-2010 |
