| 摘要 |
PURPOSE:To enable appropriate X-ray exposure to be provided by installing a multi-lighting part consisting of a plural number of channels within the visual field of the lighting of image intensifier output, and setting the exposure condition on the basis of a channel with appropriate X-ray exposure. CONSTITUTION:A multi-lighting part 11 consisting of channels 11A-11N is installed within the visual field of the lighting of image intensifier output. A high level is sent out when the lighting amount of one of the chnnels 11A-11N is excessive or deficient, while a low level is sent out when the lighting amount is appropriate. Each output sent from the channels 11A-11N is fed into a latch circuit 23 through an over-under detection circuit 19. The circuit 23 turns on one of analog switches 12A-12N which corresponds to one of the channels 11A- 11N having a low level, and analog outputs are sent out through an adding circuit 13 into a dividing circuit 14. The number of channels with low levels are counted with a counting circuit 24, and the counted number is sent out into the circuit 14, and the average value per channel is simultaneously given to an X-ray irradiation condition setting circuit or the like by means of the circuit 14. Consequently, appropriate X-ray exposure can be provided. |
