X-ray or infrared imaging device, of the radiography or scanography type, comprising: a support (1) for receiving a body (3) to be examined a source (5) supplying a focus (F, F1, F2), from which there emanates an X-ray or light beam (7,71,72) that passes through a slit (8) in a dose limiter (8, 8a, 8b) translationally controlled so as to scan the body (3) to be examined a detector (9) translationally controlled so as to be irradiated or illuminated by the beam scanning the body (3) to be examined and to detect an attenuated intensity as a function of the X-rays or light rays passing through the body (3) to be examined an analogue-to-digital converter (11), for converting the detected intensities into data for determining an attenuation by the body (3) to be examined of the X-rays or light rays and a computer (13) programmed to process the data coming from the conversion of the detected intensities in order to result in an image expressing the attenuation of the X-rays or light rays by the examined body (3). According to the invention, the dose limiter (8, 8a, 8b) is translationally controlled with a speed proportional to that of the detector (9), said speed being controlled by the ratio (D2/D1) of the distance (D1) between the focus (F,F1,F2) and the detector (9) to the distance (D2) between the focus (F, F1, F2) and the dose limiter (8, 8a, 8b).Dispositif dimagerie X ou infrarouge, du type radiographie ou scanographie, comprenant : - un support (1 ) pour recevoir un corps à examiner (3), - une source (5) alimentant un foyer (F,F1,F2) dont est issu un faisceau (7,71,72) (7) de rayons X ou lumineux traversant une fente (8) dun limiteur de dose (8, 8a, 8b) commandé en translation pour balayer le corps à examiner (3), - un détecteur (9) commandé en translation pour être irradié ou illuminé par le faisceau balayant le corps à examiner (3) et détecter une intensité atténuée en fonction dune traversée des rayons X ou lumineux à travers le corps à examiner (3), - un conver
