| 摘要 |
PURPOSE:To permit the control of halation by reducing scattered radiation by a procedure in which paired two blades of quadrilateral blades made of an X-ray-impervious material are divided into two, respectively, so as to enable them to be adjusted in shape according to the shape of an object to be photographed. CONSTITUTION:The blades 2 and 2' of the quadrilateral blade 18 made of an X- rays-impervious material are divided into the two, or the blades 2a, 2b, 2a', and 2b', respectively, and the ends of the blades 2a and 2b' are provided with the pins 3 and 3' with respective screw portions. Also, the ends of the blades 2b and 2a' are provided with the slender grooves 4 and 4' which are, in turn, fitted on the pins 3 and 3'. In case where the affected portion of the object to be photographed is relatively small, the driving motor 17 is first actuated to turn the gear 13 in the direction of the arrow mark, the lining 10 is shifted along the guide cylinder 9 through the lever 12, and then the irradiation field is determined by the said quadrilateral blade 18. |
