Positioning unit for radiation tomography apparatus

摘要

A positioning unit for a radiation tomography apparatus comprises light beam detector and a light beam generator which are disposed opposite to each other on a horizontal line passing through the center of a photographing region irradiated by X-rays, a table top on which a patient is laid, driving device for driving the table top in the vertical direction, position detector for outputting a signal whose magnitude corresponds to the position of the table top; and controller which obtains data corresponding to the distance from an upper surface of a part of body to be photographed of the patient to the horizontal line of the photographing region, based on an output signal of the light beam detector and an output signal of the position detector. The controller obtains distance data for aligning the horizontal line passing through the center of the photographing region with the center of the part of body to be photographed, in accordance with the distance data and data corresponding to the horizontal line, and it drives the driving device until a signal which corresponds to desired distance data is output from the position detector.