| 摘要 |
An X-ray photographing device of a digital fluorographic apparatus for use in X-ray diagnosis includes an image intensifier for converting X-rays transmitted through an object to an optical image, and a TV camera for converting the optical image to a television video signal. An effective video level range of the TV camera is narrower than that of the image intensifier. In order to perform a proper X-ray transmittance correction for the object, an X-ray television video signal is converted, at levels out of the effective video level range of the TV camera, to a maximum allowable input video level. In a TV monitor, the levels of the television signal which are out of the effective video signal level range of the TV camera are displayed at the maximum signal level to permit a ready transmittance correction operation. The subtraction image is displayed in accordance with the proper corrected levels. |
